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1.
Plant Physiol Biochem ; 207: 108316, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38176189

RESUMO

Mulberry (Morus alba) is an essential plant with countless economic benefits; however, its growth and metabolic processes are hampered by boron (B) stresses. Very little research has been performed to elucidate boron tolerance and detoxification mechanisms in this species. The M. alba cultivar, Yu-711, was exposed to five different concentrations of boric acid (H3BO3), including deficient (T1; 0 mM) moderate B deficiency (T2; 0.02 mM), sufficient (CK; 0.1 mM) and toxic (T3 and T4; 0.5 and 1 mM) levels for 18 days of growth in pots experiment. Transcriptome analysis of B deficiency and toxicity treatments was performed on mulberry leaves. The transcriptome data reveal that a total of 6114 genes were differentially expressed (DEGs), of which 3830 were up-regulated and 2284 were down-regulated. A comparative analysis between treatment groups CK-vs-T1 (deficiency) and CK-vs-T4 (toxicity) indicates that 590 and 1383 genes were down-regulated in both deficiency and B toxicity, respectively. The results show that 206 genes were differentially expressed in all treatments. B deficiency and toxicity significantly altered the expression of the key aquaporins (PIP2-1, PIP2-7, PIP2-4 and NIP3-1) and high-affinity boron transporter genes (BOR1 and BOR7). In addition, boron stress also altered the expression of antioxidants and photosynthesis-related genes. B stresses were found to alter several transcription factors including ERF1B, which is associated with the regulation of boron uptake and the synthesis and signaling of phytohormones. Unravelling the mechanisms of B tolerance and detoxification is important and would give us further insight into how B stresses affect mulberry plants.


Assuntos
Morus , Morus/genética , Boro/toxicidade , Boro/metabolismo , Perfilação da Expressão Gênica/métodos , Transcriptoma/genética , Folhas de Planta/metabolismo
2.
Food Chem ; 426: 136624, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37356242

RESUMO

This study investigated effects of insoluble dietary fiber (IDF) from wheat bran on starch digestion in vitro, analyzed the inhibition kinetics of IDF toward α-amylase and discussed the underlying mechanisms. Digestion results showed IDF significantly retarded starch digestion with reduced digestion rate and digestible starch content. Enzyme inhibition kinetics indicated IDF was a mixed-type inhibitor to α-amylase, because IDF could bind α-amylase, as evidenced by confocal laser scanning microscopy. Fluorescence quenching and UV-vis absorption experiments conformed this, found IDF led to static fluorescence quenching of α-amylase, mainly through van der Waals and/or hydrogen bonding forces. This interaction induced alternations in α-amylase secondary structure, showing more loosening and misfolding structures. This may prevent the active site of enzyme from capturing substrates, contributing to reduced α-amylase activity. These results would shed light on the utilization of IDF in functional foods for the management of postprandial blood glucose.


Assuntos
Fibras na Dieta , alfa-Amilases , Amido/química , Glicemia , Digestão
3.
ChemSusChem ; 16(9): e202202216, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-36797983

RESUMO

Solid-state batteries have become one of the hottest research areas today, due to the use of solid-state electrolytes enabling the high safety and energy density. Because of the interaction with electrolyte salts and the abundant ion transport sites, natural polysaccharide polymers with rich functional groups such as -OH, -OR or -COO- etc. have been applied in solid-state electrolytes and have the merits of possibly high ionic conductivity and sustainability. This review summarizes the recent progress of natural polysaccharides and derivatives for polymer electrolytes, which will stimulate further interest in the application of polysaccharides for solid-state batteries.

4.
Bioengineering (Basel) ; 10(2)2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36829656

RESUMO

(1) Background: A combination of radiofrequency (RF) volumetric heating and convection cooling has been proposed to realize plaque ablation while protecting the endothelial layer. However, the depth of the plaque and the thickness of the endothelial layer vary in different atherosclerotic lesions. Current techniques cannot be used to achieve penetrating heating for atherosclerosis with two targets (the specified protection depth and the ablation depth). (2) Methods: A tissue-mimicking phantom heating experiment simulating atherosclerotic plaque ablation was conducted to investigate the effects of the control parameters, the target temperature (Ttarget), the cooling water temperature (Tf), and the cooling water velocity (Vf). To further quantitatively analyze and evaluate the ablation depth and the protection depth of the control parameters, a three-dimensional model was established. In addition, a conformal penetrating heating strategy was proposed based on the numerical results. (3) Results: It was found that Ttarget and Tf were factors that regulated the ablation results, and the temperatures of the plaques varied linearly with Ttarget or Tf. The simulation results showed that the ablation depth increased with the Ttarget while the protection depth decreased correspondently. This relationship reversed with the Tf. When the two parameters Ttarget and Tfwere controlled together, the ablation depth was 0.47 mm-1.43 mm and the protection depth was 0 mm-0.26 mm within 2 min of heating. (4) Conclusions: With the proposed control algorithm, the requirements of both the ablation depth and the endothelium protection depth can be met for most plaques through the simultaneous control of Ttarget and Tf.

5.
Int J Hyperthermia ; 40(1): 2122597, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36642421

RESUMO

OBJECTIVES: The outcome of balloon-based atherosclerosis thermoplasty is closely related to the temperature/stress distribution during the treatment. For precise prediction of a required thermal lesion in the heterogeneous and thin atherosclerotic vessel, a numerical model incorporating heat-induced tissue expansion or shrinkage and the strain caused by balloon dilation is necessary. METHODS: A fully coupled thermal-electrical-structural new model was established. The model features a heterogeneous structure including eccentric plaque, healthy artery and surrounding tissue. Tissue expansion/shrinkage and hyperelasticity material model were taken into consideration. Different heating strategies and plaque mechanical properties were investigated. The temperature distribution was compared with the traditional thermal-electrical coupled model. The possibility of thermoplasty treatment using balloons with different sizes was also explored. RESULTS: The temperature, the electrical intensity and the stress during the thermoplasty were obtained. Lower stress was found in the heating region where tissue shrinkage occurred. The ablation depth was predicted to be ∼0.42 mm larger without coupling the biomechanical influence. The mechanical properties and input condition significantly affect the temperature and stress distribution considering the small dimensions of the tissue. Besides, with a 12.5% reduction of balloon diameter, the largest Von Mises stress decreases by 25.4%. CONCLUSIONS: It is confirmed that a coupled thermal-electrical-structural model is needed for precise temperature prediction in the balloon-based thermoplasty of the heterogeneous and thin tissue. The model presented may help with future development of optimized treatment planning considering both ablation depth and minimum stress.


Assuntos
Aterosclerose , Temperatura Alta , Humanos , Temperatura
6.
Chem Commun (Camb) ; 58(85): 11993-11996, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36217964

RESUMO

Redox-active organic materials have shown great potential as electrodes in lithium-ion batteries (LIBs). However, most of them showed a low discharge potential. We report a thianthrene-based small molecule (BDBDT), which could be facilely synthesized, as a high-potential cathode. The BDBDT cathode exhibited good electrochemical performance with a discharge plateau at 3.9 V (vs. Li/Li+) and a discharge capacity of 63 mA h g-1 after 100 cycles at 500 mA g-1 (∼10C). Our results demonstrate that thianthrene-based molecules are promising for the development of high-potential organic electrodes towards rechargeable batteries with high energy and power density.

7.
Angew Chem Int Ed Engl ; 61(37): e202116289, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-35005819

RESUMO

Aqueous zinc-ion batteries (ZIBs) are promising for next-generation energy storage. However, the reported electrode materials for ZIBs are facing shortcomings including low capacity and unsatisfactory cycling stability etc. Herein, hexaazatrinaphthalene-quione (HATNQ) is reported for aqueous ZIBs. The HATNQ electrodes delivered an ultrahigh capacity (482.5 mAh g-1 at 0.2 A g-1 ) and outstanding cyclability of >10 000 cycles at 5 A g-1 . The capacity sets a new record for organic cathodes in aqueous ZIBs. The high performances are ascribed to the rich C=O and C=N groups that endowed HATNQ with a 2D layered supramolecular structure by multiple hydrogen bonds in plane with π-π interactions out-of-plane, leading to enhanced charge transfer, insolubility, and rapid ion transport for fast-charge and -discharge batteries. Moreover, the 2D supramolecular structure boosted the storage of Zn2+ /H+ , particularly the storage of Zn2+ , due to the more favorable O⋅⋅⋅Zn⋅⋅⋅N coordination in HATNQ.

8.
IEEE J Biomed Health Inform ; 26(5): 2158-2168, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34727042

RESUMO

Accurate and continuous measurement of the human core body temperature by a wearable device is of great significance for human health care and disease monitoring. The current wearable thermometers ignore the physiological differences between individuals and the role of blood perfusion in thermoregulation, resulting in insufficient accuracy and limitations in terms of the measurement sites. This study proposed a novel personal model for measuring core body temperature by taking dynamic tissue blood perfusion and individual differences into consideration. The technique facilitates possible accurate core body temperature measurements from the skin surface of the wrist and forehead. First, the personal core body temperature model was established based on the thermal equilibrium between the human body and the measurement device, in which the tissue blood perfusion changes dynamically with tissue temperature. Then, the parameters of the personal model that imply individual physiological differences were obtained based on personal data collected daily. The results show that with the developed personal model, the accuracy of the measured body temperature from the wrist is close to that of the forehead model. The wrist model and the forehead model have a mean absolute error of 0.297 (SD = 0.078)°C and 0.224 (SD = 0.071)°C, respectively, which meets the accuracy and robustness requirements of practical applications. The personal models significantly improve the accuracy compared with that of the group model, especially for the wrist model.


Assuntos
Temperatura Corporal , Dispositivos Eletrônicos Vestíveis , Temperatura Corporal/fisiologia , Humanos , Individualidade , Perfusão , Temperatura Cutânea , Termômetros
9.
Opt Express ; 28(26): 39241-39249, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33379478

RESUMO

In the second-harmonic generation processes involving Laguerre-Gaussian (LG) beams, the generated second-harmonic wave is generally composed of multiple modes with different radial quantum numbers. To generate single-mode second-harmonic LG beams, a type of improved quasi-phase-matching method is proposed. The Gouy phase shift has been considered in the optical superlattice designing and an adjustment phase item is introduced. By changing the structure parameters, each target mode can be phase-matched selectively, whose purity can reach up to 95%. The single LG mode generated from the optical superlattice can be modulated separately and used as the input signals in the mode division multiplexing system.

10.
Zhongguo Yi Liao Qi Xie Za Zhi ; 44(6): 503-507, 2020 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-33314858

RESUMO

According to the actual requirements of pediatric intensive care, a suction detection system of pediatric oral secretions integrated with monitoring function is designed. The system has the function of adjustable intermittent attraction. The duration and proportion of intermittent attraction can be adjusted according to the individualized needs of pediatric intensive care. The suction head of pacifier can reduce the mechanical damage to pediatric oral mucosa as much as possible. Meanwhile, the system can detect and monitor the real-time biochemical indexes of the collected oral secretions, which can be used to help the judgement of aspiration and quantitatively evaluate the microcirculation dysfunction.


Assuntos
Secreções Corporais , Boca , Sucção/instrumentação , Criança , Humanos
11.
Biomed Eng Online ; 19(1): 44, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522205

RESUMO

BACKGROUND: Restenosis remains a challenge in the treatment of atherosclerosis due to damage to the endothelial layer and induced proliferation of smooth muscle cells. A novel radiofrequency (RF) heating strategy was proposed to selectively ablate atherosclerosis plaque and to thermally inhibit the proliferation of smooth muscle cells while keeping the endothelial cells intact. METHODS: To realize the proposed strategy, a new radiofrequency balloon catheter, consisting of three ports, a three-channel tube, a balloon and an electrode patch, was designed. To evaluate the feasibility of this new design, a phantom experiment with thermocouples measuring temperatures with different voltages applied to the electrodes was conducted. A numerical model was established to obtain the 3D temperature distribution. The heating ability was also evaluated in ex vivo diseased artery samples. RESULTS: The experimental results showed that the highest temperature could be achieved in a distance from the surface of the balloon as designed. The temperature differences between the highest temperature at 0.78 mm and those of the surface reached 9.87 °C, 12.55 °C and 16.00 °C under applied 15 V, 17.5 V and 20 V heating, respectively. In the circumferential direction, the heating region (above 50 °C) spread from the middle of the two electrodes. The numerical results showed that the cooling effect counteracted the electrical energy deposition in the region close to the electrodes. The thermal lesion could be directed to cover the diseased media away from the catheter surface. The ex vivo heating experiment also confirmed the selective heating ability of the device. The temperature at the targeted site quickly reached the set value. The temperature of the external surface was higher than the inner wall surface temperature of the diseased artery lumen. CONCLUSION: Both the experimental and numerical results demonstrated the feasibility of the newly designed RF balloon catheter. The proposed RF microelectrodes heating together with the cooling water convection can realize the desired heating in the deeper site of the blood vessel wall while sparing the thin layer of the endothelium.


Assuntos
Angioplastia com Balão/instrumentação , Aterosclerose/terapia , Ondas de Rádio , Eletrodos , Imagens de Fantasmas , Temperatura
12.
Chemosphere ; 251: 126372, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32169707

RESUMO

Heavy metal pollution is becoming an increasingly serious problem globally, and cadmium pollution ranks first in the world. Reproduction in insects is affected by cadmium stress in a dose-dependent manner. However, no previous studies have examined the molecular mechanisms underlying the influence of cadmium exposure on insect reproduction. In this study, RNA-Seq was used to investigate changes in ovary gene expression in newly emerged female beet army worms. The beet armyworms were reared under 4 cadmium concentrations: 0 mg/kg (control), low 0.2 mg/kg (L), medium 12.8 mg/kg (M) and high 51.2 mg/kg (H). Compared with the control (CK), a total of 3453 differentially expressed genes (DEGs) were identified in L cadmium stress, including 1791 up-regulated and 1662 down-regulated candidates; in L versus M groups, 982 up-regulated and 658 down-regulated DEGs; and in M versus H groups, 6508 up-regulated and 2000 down-regulated DEGs were identified and the expression patterns of ten genes were verified by q PCR. Many of the identified DEGs were relevant to juvenile hormone and molting hormone biosynthesis, insulin secretion, estrogen signaling, amino acid metabolism and lipid biosynthesis. These data will provide a molecular prospective to understand the ecological risk of heavy metal pollution and are a resource for selecting key genes as targets in gene-editing/silencing technologies for sustainable pest management.


Assuntos
Cádmio/toxicidade , Poluentes do Solo/toxicidade , Spodoptera/fisiologia , Animais , Antioxidantes , Beta vulgaris , Cádmio/metabolismo , Feminino , Perfilação da Expressão Gênica , Ovário/metabolismo , Estudos Prospectivos , Poluentes do Solo/metabolismo , Spodoptera/metabolismo , Transcriptoma
13.
IEEE Trans Biomed Eng ; 66(9): 2663-2670, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30676939

RESUMO

OBJECTIVES: Restenosis remains a challenge for the treatment of atherosclerosis due to the damage of the endothelial layer and induced proliferation of the smooth muscle cell. METHODS: A new RF heating strategy was proposed to selectively ablate the atherosclerosis plaque, and to thermally inhibit the proliferation of smooth muscle cells, while keeping the endothelial cells intact. To achieve the goal, an internal cooling agent and distributed electrodes have been integrated in the new designed balloon catheter to focus the shape conformal energy onto the plaque shape. A three-dimensional (3-D) model with experimentally fitted parameters has been established to demonstrate the heating ability of the design and evaluate the microelectrodes configurations for different plaque geometries. RESULTS: The 3-D shape of the lesions resulting from different electrodes settings is obtained. It is found that by individual control of the micro-electrodes, special shapes of the lesions can be formed, which can match the eccentric crescent plaques. Besides, through changing of the polarity of the electrodes, separate lesions can be reached. This suggests the possibility for treatment of disconnected plaques in situ. CONCLUSION: By the control of RF heating and convection coefficient of the internal cooling agent, a targeted heating region away from the inner surface of the blood vessel can be realized. SIGNIFICANCE: This study has illustrated the possibility of achieving a precision thermal treatment of atherosclerosis in favor of inhibiting further restenosis.


Assuntos
Aterosclerose/terapia , Imageamento Tridimensional/métodos , Ablação por Radiofrequência , Eletrodos , Células Endoteliais , Desenho de Equipamento , Humanos , Modelos Cardiovasculares , Imagens de Fantasmas , Ablação por Radiofrequência/instrumentação , Ablação por Radiofrequência/métodos
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 5514-5517, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31947103

RESUMO

This study proposed a control strategy of the ablation margin using the temperature of the probe, without causing additional damage. Compared with other methods, the proposed strategy is real time and impedance-ignored, thus has a better performance in practice. A theoretical model was established to obtain the temperature distribution during the treatment. Several functions were obtained by fitting the results of the simulation model, with which a preset central temperature curve corresponding to a desired ablation zone was determined to regulate the temperature of the control point. Considering the various impedances in practice, a voltage adjustment method according to the error between the preset central temperature and the practical central temperature was proposed to minimize the effect of impedances. At last, the strategy was verified with phantom experiments. The results show that all the temperatures of the control points reached to 50°C at a specific time and kept for a while, which demonstrated the strategy had a good performance within the error range allowed.


Assuntos
Ablação por Cateter , Impedância Elétrica , Modelos Teóricos , Temperatura Corporal , Temperatura
15.
Zhongguo Yi Liao Qi Xie Za Zhi ; 42(6): 409-412, 2018 Nov 30.
Artigo em Chinês | MEDLINE | ID: mdl-30560617

RESUMO

In order to support study of new radiofrequency ablation treatments and finally realize of precise conformal ablation of targeted tissue, this paper proposed a system which is able to generate radio frequency currents at different frequencies. The designed system bases on the basic principle of Class E power amplifier and uses MSP430 microcontroller as a controller and uses a touch screen as human-machine interface to design a frequency-selectable radiofrequency ablation treatment system,. The RF signals at frequencies of 230 kHz, 460 kHz, 920 kHz, and 2 000 kHz were tested to verify the feasibility of the system, and by using a tissue phantom, tested the heating ability of the RF signals at frequencies of 460 kHz, 920 kHz, and 2 000 kHz. The results show the device could well heat the tissue at the three frequencies. The study has also found that both the highest temperature and the ablation area decreases with RF frequency, when using the constant power control mode.


Assuntos
Ablação por Cateter , Ondas de Rádio , Ablação por Cateter/instrumentação , Temperatura Alta , Humanos , Hipertermia Induzida , Imagens de Fantasmas
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 3232-3235, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30441080

RESUMO

Numerical simulations provide effective way to acquire detailed temperature field during radiofrequency ablation (RF). Based on the patient's real electrical resistance and RF power, we have designed a theoretical model suitable for clinical treatment planning. The human body is assumed to be two cylinders with the inner cylinder simulating the liver with real liver electrical conductivity, while the electrical conductivity of the out cylinder adjusted to match the real resistance recorded when treated with RFA. The orthogonal-array method has been applied to analyze the impact of the main geometric parameters. Results show that a limited range of model parameters with the same resistance and power condition results in similar prediction of ablation range. In addition, RF heating experiments have been performed in the liver of a live pig to validate this model. The simulated temperature fits well with the real temperature. The comparison of the results predicted using the proposed model and previous models finds that the previous uniform-electrical-conductivity model would significantly underestimates or overestimates the ablation range based on the magnitude of the electrical resistance recorded.


Assuntos
Ablação por Cateter , Animais , Condutividade Elétrica , Impedância Elétrica , Humanos , Fígado , Suínos , Temperatura
17.
Int J Hyperthermia ; 35(1): 79-89, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29865914

RESUMO

In our previous animal model study, we found that radiofrequency (RF) ablation of pre-frozen tumor resulted in improved therapeutic effects. To understand the underlying mechanisms and optimize the treatment protocol, the RF heating pattern in pre-frozen tissue was studied in this paper. Both ex vivo and in vivo experiments were conducted to compare the temperature profiles of RF heating with or without pre-freezing. Results showed that the heating rate of in vivo tissues was significantly higher with pre-freezing. However, little difference was observed in the heating rate of ex vivo tissues with or without pre-freezing. In the histopathologic analysis of in vivo tissues, both a larger ablation area and a wider transitional zone were found in the tissue with pre-freezing. To investigate the cause for the enhancement in RF heating, the parameters affecting the tissue temperature rise were studied. It was found that the electrical conductivity of in vivo tissue with pre-freezing was much higher at low frequencies, but little difference was found at the 460 kHz frequency commonly used in clinical applications. A finite element model for RF heating was developed and validated to fit the thermal conductivity of in vivo tissue including effects of pre-freezing and the associated blood perfusion rate. Results showed that the enhancement of the heating rate was primarily attributed to the decreased blood perfusion rate in the tissue with vascular damage caused by pre-freezing. The ablation volume was increased by 104% due to the reduced heat dissipation.


Assuntos
Criopreservação/métodos , Temperatura Alta/uso terapêutico , Neoplasias/radioterapia , Terapia por Radiofrequência , Animais , Ablação por Cateter/métodos , Modelos Animais , Neoplasias/patologia
18.
Pestic Biochem Physiol ; 140: 51-57, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28755694

RESUMO

Spodoptera exigua is a secondary target pest of Bt cotton commercialized in China. With the continuous adoption of Bt cotton, populations of S. exigua have gradually increased. However, the cold tolerance ability of Bt-resistant S. exigua and the effect of continuous Bt diet on anti-cold materials are unknown. In our study, it was found that Bt-resistant S. exigua (Bt10) developed better with shorter larval and pupal duration and higher pupation rate compared to CK at the suboptimal low temperature. The supercooling points and freezing points of the Bt-resistant S. exigua strain were determined, and body water content and anti-cold materials such as total sugar, trehalose and glycogen, glycerol and fat were examined to explore the effect of Bt toxin on overwintering and on population increase. The results showed that the supercooling point and the freezing point of the Bt-resistant S. exigua pupae were both significantly lower than that of the Bt-susceptible strain. No difference was found in the body water content of pupae and adults between the two strains. Total sugar content of the Bt-resistant strain at both the pupal and adult stages was higher than that of the susceptible strain at the corresponding stages, and glycogen content of the Bt-resistant strain at the larval stage was higher than that of the susceptible larval S. exigua. Fat content of the Bt-resistant larvae, pupae and adults was for each higher than that of the susceptible strain, but the difference was not significant except for that of the 3rd instar larvae. Glycerol content of the Bt-resistant strain at larval, pupal and adult stages was for each higher than that of the corresponding life stages of the susceptible strain. It can be seen that more glycerol was accumulated in Bt-resistant S. exigua. The results indicate that Bt-resistant S. exigua has better cold tolerance. The contents of the anti-freeze substances of progeny, especially glycerol, were increased after previous generations were continuously fed on Bt protein, which means that the Bt-resistant secondary target pests could more easily overcome the overwinter season and become a source of crop damage the following year.


Assuntos
Proteínas de Bactérias/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Resistência a Inseticidas/genética , Spodoptera/efeitos dos fármacos , Animais , Toxinas de Bacillus thuringiensis , Carboidratos/química , Temperatura Baixa , Glicerol/metabolismo , Larva/química , Larva/fisiologia , Pupa/química , Pupa/fisiologia , Spodoptera/química
19.
Zhongguo Yi Liao Qi Xie Za Zhi ; 41(4): 240-243, 2017 Jul 30.
Artigo em Chinês | MEDLINE | ID: mdl-29862779

RESUMO

In order to solve the heat transfer mechanism in radiofrequency treatment of atherosclerosis, we design two experimental structures to simulate the plaque, and use three frequencies and a variety of electrode arrangement, to study the heat transfer mechanism and heating capacity under the special structure. The results show that the temperature increment and heating area increase with increasing frequency. Under the structure in which the lipid particles are embedded in the fiber cap, using three electrodes with opposite polar arrangement between middle electrode and others, achieves effective heating to lipid pool in the plaque.


Assuntos
Aterosclerose/terapia , Ablação por Cateter/instrumentação , Eletrodos , Humanos , Ondas de Rádio
20.
Appl Microbiol Biotechnol ; 99(4): 1897-910, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25398282

RESUMO

The antagonistic activity of lipopeptides in Bacillus subtilis 916 has been well documented, yet relatively little is known about their mechanism in biofilm formation and environmental colonization. This study sought to examine the interaction of B. subtilis 916 on Rhizoctonia solani-infected rice sheath to elucidate the mechanism of colonization on plant leaves. Results showed that the mutants Δbac, Δsrf, and Δsrf + bac of B. subtilis 916, deficient in bacillomycin L and surfactin production, respectively, not only altered colony morphology but also changed swarming motility, reduced antagonistic activity, and decreased biofilm formation. In particular, biofilm formation in mutant Δbac, not Δsrf or Δsrf + bac, were restored with addition of surfactin and bacillomycin L at 10 and 50 µg/mL, respectively. Moreover, surfactin and bacillomycin L were able to restore or enhance swarming motility in the corresponding mutants at 10 µg/mL, respectively. With the aid of green fluorescent protein tagging, it was demonstrated that B. subtilis 916 formed a robust biofilm on the rice sheath blight lesion and colonized well on R. solani-infected rice sheath, while its corresponding mutants performed poorly. These observations also correlated with the rice cultivar pot experiments, in which B. subtilis 916 exhibited greater biocontrol than its mutants. Our results suggest that surfactin and bacillomycin L contribute differently but synergistically to the biocontrol of rice sheath blight in B. subtilis 916 through its antifungal activity, biofilm formation, and colonization.


Assuntos
Antibiose , Antifúngicos/farmacologia , Bacillus subtilis/fisiologia , Sinergismo Farmacológico , Lipopeptídeos/metabolismo , Peptídeos Cíclicos/metabolismo , Rhizoctonia/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/metabolismo , Biofilmes/crescimento & desenvolvimento , Deleção de Genes , Genes Bacterianos , Locomoção , Oryza/microbiologia , Controle Biológico de Vetores/métodos , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Folhas de Planta/microbiologia
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