Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Zhongguo Zhong Yao Za Zhi ; 44(10): 2015-2019, 2019 May.
Artigo em Zh | MEDLINE | ID: mdl-31355554

RESUMO

This study was aimed to clarify the toxicity indoor and inhibition effect of biocontrol strain NJ13 and its mixture with chemical fungicides against Fusarium solani causing ginseng root rot. The method of mycelial growth rate and Sun Yunpei method were used to determine the indoor toxicity and co-toxicity coefficient of strain NJ13 and their mixture with chemical pesticides against F. solani. The dual culture assay method,mixed culture method and microscopic observation were used to determine the sporulation and germination of spores and mycelial growth and morphological change of hyphae of F. solani treated by strain NJ13. The results of toxicity indoor showed that strain NJ13 had the best inhibitory effect on pathogen,and its EC_(50) value was 0. 071 mg·L~(-1). It was all synergistic for antifungal effect that strain NJ13 was mixed with propiconazole and difenoconazole respectively with a range from 1 ∶4 to 4 ∶1( volume ratio). Both of optimal ratios were 1 ∶1,and the co-toxicity coefficients were 848. 70 and 859. 73,respectively. The strain NJ13 could inhibit the sporulation,germination and mycelial growth of F. solani. The biocontrol strain NJ13 had an inhibition effect on F. solani,and the optimal antifungal ratio of strain NJ13 mixed with propiconazole and difenoconazole was obtained.


Assuntos
Bactérias , Agentes de Controle Biológico , Fungicidas Industriais , Fusarium/patogenicidade , Panax/microbiologia , Raízes de Plantas/microbiologia
2.
Zhongguo Zhong Yao Za Zhi ; 43(11): 2230-2235, 2018 Jun.
Artigo em Zh | MEDLINE | ID: mdl-29945372

RESUMO

This study was aimed to isolate the strains with both disease resistance and growth-promoting, and clarify the field application effects of the strain for laying the further application foundation. The strains with good antagonistic effect were isolated from the 298 strains in Panax ginseng and the soil by plate confrontation method. The nitrogen fixation potential was verified by Ashby medium. The Salkowski method was used to determine the ability of producing IAA. Silicate medium screening and flame spectrophotometry was used to determine the ability of dissolving potassium. CAS method was applied to detect the ability of producing siderophores to determine its growth characteristics. The morphological, physiological and biochemical and 16S rRNA sequences were used to identify the species. The method of root irrigation was used to determine the effects of its disease control and growth-promoting on ginseng. A strain TY15 with broad spectrum of antimicrobial effect, nitrogen fixation, potassium-dissolving and the capacity of producing IAA and siderophores was obtained by screening. And the strain TY15 was identified as Pantoea agglomerans. The control effect of TY15 on the disease of ginseng in the field was 68.02%, which was equivalent to 68.94% of 30 billion per gram of beneficial microecological bacterium agent. The fresh weight of P. ginseng treated with TY15 strain was increased by 22.73% compared with the control group treated with water. And finally a strain TY15 with good application prospects was obtained.


Assuntos
Resistência à Doença , Panax/microbiologia , Pantoea/classificação , Microbiologia do Solo , Ácidos Indolacéticos , Fixação de Nitrogênio , Pantoea/isolamento & purificação , Filogenia , RNA Ribossômico 16S
3.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 38(4): 393-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27594150

RESUMO

Objective To evaluate the effect of interventions for premature ejaculation (PE) in the management of patients with chronic prostatitis and secondary premature ejaculation. Methods Totally 90 patients diagnosed as chronic prostatitis with PE were randomly divided into control group (n=45) and interventional group (n=45). Control group received a conventional therapy consisted of oral administration of antibiotics,α-receptor blocker,and proprietary Chinese medicine for clearing away heat and promoting diuresis. Interventional group received a conventional therapy combined with treatment for ameliorating the PE symptom (oral dapoxetine on-demand and ejaculation control exercise).National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI),Chinese Index of Sexual Function for Premature Ejaculation (CIPE)-5 questionnaires,intravaginal ejaculatory latency time,and the number of coituses per week were applied for evaluating the treatment outcomes. Results Follow-up was accomplished in 35 and 38 patients in the control and interventional group.The CIPE-5 score,intravaginal ejaculatory latency time,and the number of coituses per week were significantly improved in both two groups but more significantly in interventional group (all P<0.05). The NIH-CPSI pain,urination,and quality of life subscores and total score were improved significantly in both two groups after treatment,but the NIH-CPSI pain and quality of life subscores had been improved more significantly in the interventional group (all P<0.05). The variation of NIH-CPSI was negatively correlated with that of CIPE-5 in both two groups (r=-0.362,P=0.016;r=-0.330,P=0.021). Conclusions For CP with secondary PE patients,the interventions for PE can not only improve the quality of sexual life but also help improve the NIH-CPSI pain and quality of life subscores. PE should be routinely screened and treated during the management of CP.p.


Assuntos
Ejaculação Precoce/tratamento farmacológico , Ejaculação Precoce/etiologia , Prostatite/complicações , Prostatite/tratamento farmacológico , Antibacterianos/uso terapêutico , Doença Crônica , Dor Crônica , Coito , Medicamentos de Ervas Chinesas/uso terapêutico , Ejaculação , Humanos , Masculino , Qualidade de Vida , Inquéritos e Questionários , Resultado do Tratamento
4.
Zhongguo Zhong Yao Za Zhi ; 40(2): 213-7, 2015 Jan.
Artigo em Zh | MEDLINE | ID: mdl-26080547

RESUMO

Endophytic bacteria which was producing indoleacetic acid was screened from Panax ginseng by using the Salkowski method. The active strain was also tested for its ability of nitrogen fixation by using the Ashby agar plates, the PKV plates and quantitative analysis of Mo-Sb-Ascrobiology acid colorimetry was used to measure its ability of phosphate solubilization, for its ability of potassium solubilization the silicate medium and flame spectrophotometry was used, for its ability of producing siderophores the method detecting CAS was used, for its ability of producing ACC deaminase the Alpha ketone butyric acid method was applied. And the effect on promoting growth of seed by active strain was tested. The results showed that the indoleacetic acid producing strain of JJ5-2 was obtained from 118 endophytes, which the content of indoleacetic acid was 10.2 mg x L(-1). The JJ5-2 strain also had characteristics of phosphate and potassium solubilization, nitrogen fixation, producing siderophores traits, and the promoting germination of ginseng seeds. The JJ5-2 strain was identified as Bacillus thuringiensis by analyzing morphology, physiological and biochemical properties and 16S rRNA gene sequences.


Assuntos
Bactérias/isolamento & purificação , Endófitos/isolamento & purificação , Ácidos Indolacéticos/metabolismo , Panax/microbiologia , Bactérias/metabolismo , Endófitos/metabolismo
5.
Zhongguo Zhong Yao Za Zhi ; 39(10): 1782-7, 2014 May.
Artigo em Zh | MEDLINE | ID: mdl-25282882

RESUMO

To reveal the colonization characteristics in host of endophytic biocontrol bacteria NJ13 isolated from Panax ginseng, this study obtained the marked strain NJ13-R which was double antibiotic resistant to rifampicin and streptomycin through enhancing the method of inducing antibiotic. The colonization characteristics in ginseng and its biocontrol efficiency against Alternaria spot of ginseng in the field were studied. The results showed that the strain could colonize in root, stem and leaf of ginseng and the colonization amount was positive correlated with inoculation concentration. Meanwhile, the strain could infect and then transfer in different tissues of ginseng The colonization amount of strain in roots and leaves of ginseng increased first and then decreased. However, the tendency of colonization amount of strain in stems was ascend at first and then descend slowly, and was more than that in roots and leaves along with time, which had a preference to specific tissue of its host. In field experiment, the endophytic bacteria NJ13 was proved to be effective in controlling Alternaria leaf spot of ginseng. The biocontrol efficiency of fermentation broth at the concentration of 0.76 x 10(8) cfu x mL(-1) reached 75.62%, which was close to the controlling level (73.06%) of 0.67 mg x L(-1) 50% cyprodinil WG.


Assuntos
Alternaria/fisiologia , Antibiose , Bacillus/fisiologia , Endófitos/fisiologia , Panax/microbiologia , Doenças das Plantas/microbiologia , Bacillus/crescimento & desenvolvimento , Bacillus/isolamento & purificação , Endófitos/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Panax/crescimento & desenvolvimento
6.
Natl Sci Rev ; 11(9): nwae110, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39144739

RESUMO

The confinement of waves within a waveguide can enable directional transmission of signals, which has found wide applications in communication, imaging, and signal isolation. Extending this concept to static systems, where material deformation is piled up along a spatial trajectory, remains elusive due to the sensitivity of localized deformation to structural defects and impurities. Here, we propose a general framework to characterize localized static deformation responses in two-dimensional generic static mechanical metamaterials, by exploiting the duality between space in static systems and time in one-dimensional non-reciprocal wave systems. An internal time-reverse symmetry is developed by the space-time duality. Upon breaking this symmetry, quasi-static load-induced deformation can be guided to travel along a designated path, thereby realizing a stress guide. A combination of time-reverse and inversion symmetries discloses the parity-time symmetry inherent in static systems, which can be leveraged to achieve directional deformation shielding. The tailorable stress guides can find applications in various scenarios, ranging from stress shielding and energy harvesting in structural tasks to information processing in mechanical computing devices.

7.
Adv Sci (Weinh) ; 11(33): e2310241, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38898738

RESUMO

Mechanical computing provides an information processing method to realize sensing-analyzing-actuation integrated mechanical intelligence and, when combined with neural networks, can be more efficient for data-rich cognitive tasks. The requirement of solving implicit and usually nonlinear equilibrium equations of motion in training mechanical neural networks makes computation challenging and costly. Here, an explicit mechanical neuron is developed of which the response can be directly determined without the need of solving equilibrium equations. A training method is proposed to ensure the robustness of the neuron, i.e., insensitivity to defects and perturbations. The explicitness and robustness of the neurons facilitate the assembly of various network structures. Two exemplified networks, a robust mechanical convolutional neural network and a mechanical recurrent neural network with long short-term memory capabilities for associative learning, are experimentally demonstrated. The introduction of the explicit and robust mechanical neuron streamlines the design of mechanical neural networks fulfilling robotic matter with a level of intelligence.


Assuntos
Redes Neurais de Computação , Neurônios , Neurônios/fisiologia , Robótica/métodos , Humanos , Inteligência Artificial
8.
Nat Commun ; 14(1): 5204, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37626088

RESUMO

Mechanical computing requires matter to adapt behavior according to retained knowledge, often through integrated sensing, actuation, and control of deformation. However, inefficient access to mechanical memory and signal propagation limit mechanical computing modules. To overcome this, we developed an in-memory mechanical computing architecture where computing occurs within the interaction network of mechanical memory units. Interactions embedded within data read-write interfaces provided function-complete and neuromorphic computing while reducing data traffic and simplifying data exchange. A reprogrammable mechanical binary neural network and a mechanical self-learning perceptron were demonstrated experimentally in 3D printed mechanical computers, as were all 16 logic gates and truth-table entries that are possible with two inputs and one output. The in-memory mechanical computing architecture enables the design and fabrication of intelligent mechanical systems.

9.
Sci Adv ; 9(27): eadf7299, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37406119

RESUMO

The combination of broken Hermiticity and band topology in physical systems unveils a novel bound state dubbed as the non-Hermitian skin effect (NHSE). Active control that breaks reciprocity is usually used to achieve NHSE, and gain and loss in energy are inevitably involved. Here, we demonstrate non-Hermitian topology in a mechanical metamaterial system by exploring its static deformation. Nonreciprocity is introduced via passive modulation of the lattice configuration without resorting to active control and energy gain/loss. Intriguing physics such as the reciprocal and higher-order skin effects can be tailored in the passive system. Our study provides an easy-to-implement platform for the exploration of non-Hermitian and nonreciprocal phenomena beyond conventional wave dynamics.

10.
Adv Sci (Weinh) ; 10(13): e2206637, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36793150

RESUMO

Robotic materials, with coupled sensing, actuation, computation, and communication, have attracted increasing attention because they are able to not only tune their conventional passive mechanical property via geometrical transformation or material phase change but also become adaptive and even intelligent to suit varying environments. However, the mechanical behavior of most robotic materials is either reversible (elastic) or irreversible (plastic), but not transformable between them. Here, a robotic material whose behavior is transformable between elastic and plastic is developed, based upon an extended neutrally stable tensegrity structure. The transformation does not depend on conventional phase transition and is fast. By integrating with sensors, the elasticity-plasticity transformable (EPT) material is able to self-sense deformation and decides whether to undergo transformation or not. This work expands the capability of the mechanical property modulation of robotic materials.

11.
Adv Sci (Weinh) ; 10(20): e2301581, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37083263

RESUMO

Information processing using material's own properties has gained increasing interest. Mechanical metamaterials, due to their diversity of deformation modes and wide design space, can be used to realize information processing, such as computing and storage. Here a mechanical metamaterial system is demonstrated for material-based encoding and storage of data through programmed reconfigurations of the metamaterial's structured building blocks. Sequential encoding and decoding are achieved in the three-dimensional (3D) printed pixelated mechanical metamaterial via kirigami-based "pixels" with programmable, temperature-dependent bistability. The mechanical metamaterial is demonstrated via a multistep deformation of encoding messages of texts and surfaces with arrays of binary data, and then decoding them by applying a predetermined stretching and heating regimen to sequentially retrieve layers of stored information and display them on its surface. This approach serves as a general framework to enable the encoding and storage of data with mechanical metamaterials.

12.
Sci Adv ; 8(23): eabn5460, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35675398

RESUMO

Transformations in shape are critical to actuation in engineered metamaterials. Existing engineering metamaterials are typically limited to a small number of shape transformations that must be built-in during material synthesis. Here, inspired by the multistability and programmability of kirigami-based self-folding elements, a robust framework is introduced for the construction of sequentially programmable and reprogrammable mechanical metamaterials. The materials can be locked into multiple stable deployed configurations and then, using tunable bistability enabled by temperature-responsive constituent materials, return to their original reference configurations or undergo mode bifurcation. The framework provides a platform to design metamaterials with multiple deployable and reversible configurations in response to external stimuli.

13.
Zhonghua Wai Ke Za Zhi ; 49(2): 125-9, 2011 Feb 01.
Artigo em Zh | MEDLINE | ID: mdl-21426826

RESUMO

OBJECTIVE: To investigate the feasibility and safety of the treatment for thoracolumbar fractures with transpedicular intracorporeal hydroxyapatite grafting and pedicle screw fixation via paraspinal approach. METHODS: From June 2007 to December 2008, 19 cases of thoracolumbar fractures were treated with transpedicular intracorporeal hydroxyapatite grafting and pedicle screw fixation via paraspinal approach. There were 7 female and 12 male, ranging from 21 to 57 years of age (mean 40.8 years) at surgery. The time from injury to surgery varied from 1 d to 5 d (mean 2.9 d). Nineteen patients all suffered from single thoracolumbar fracture with the distribution of injury level being T(11) in 1, T(12) in 5, L(1) in 9, and L(2) in 4. According to Denis fracture classification, there were 5 compression fractures and 14 burst fractures. The mean preoperative ratio of the anterior height of the body was 57.2%, kyphosis angle was 17.6° and occupation of spinal canal was 27.7%. The mean preoperative load-sharing classification of spine fractures was 5.2. Based on the ASIA neurologic grading system, preoperative neurological function was grade B in 2 cases, C in 9 and D in 8. RESULTS: Median operating time was 83.8 min (range 60-95 min) and median blood loss was 133 ml (range 90 - 200 ml). Infection did not occur in any of the patients and the operative incisions were healing well. Average follow-up time was 19.2 months (range 12 - 36 months). At the latest follow-up, the height of the anterior border was corrected to 88.4%, the kyphosis angle was 6.1°, and the occupation of spinal canal was 8.2% on average. The postoperative neurologic function of all 19 patients was improved with grade D in 2 cases and E in 17. There were no instances of instrumentation failure and no patient had persistent postoperative back pain. CONCLUSIONS: Transpedicular intracorporeal hydroxyapatite grafting and pedicle screw fixation via paraspinal approach could provide reliable neurologic improvement in patients with incomplete neurologic deficit, and could prevent the development of kyphosis.Furthermore, it has the obvious advantages of less invasive and blood loss, and decreases the risks of postoperative lumbodorsal pain.


Assuntos
Fixação Interna de Fraturas/métodos , Vértebras Lombares/lesões , Fraturas da Coluna Vertebral/cirurgia , Vértebras Torácicas/lesões , Adulto , Parafusos Ósseos , Transplante Ósseo/métodos , Durapatita , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
14.
Nat Commun ; 12(1): 7234, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34903754

RESUMO

Embedding mechanical logic into soft robotics, microelectromechanical systems (MEMS), and robotic materials can greatly improve their functional capacity. However, such logical functions are usually pre-programmed and can hardly be altered during in-life service, limiting their applications under varying working conditions. Here, we propose a reprogrammable mechanological metamaterial (ReMM). Logical computing is achieved by imposing sequential excitations. The system can be initialized and reprogrammed via selectively imposing and releasing the excitations. Realization of universal combinatorial logic and sequential logic (memory) is demonstrated experimentally and numerically. The fabrication scalability of the system is also discussed. We expect the ReMM can serve as a platform for constructing reusable and multifunctional mechanical systems with strong computation and information processing capability.

16.
Biol Pharm Bull ; 32(8): 1406-10, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19652381

RESUMO

Hydrogen sulfide (H(2)S), as an endogenous gas signaling molecule with important biological function that has been found recently, may play a protection in ischemic reperfusion (I/R) myocardium. We investigated the cardioprotective effect of H(2)S in rats model of ischemic reperfusion in vivo and a probably influence on the expression of survivin, an anti-apoptosis gene. Animals were randomly divided into 3 groups and received either vehicle, sodium hydrosulfide (NaHS) or DL-propargylglycine (PAG) respectively everyday for 1 week before surgery and the treatment continued for a further 2 d after I/R till the animals were sacrificed. We investigated the plasma H(2)S concentration and blood pressure, with the electrocardiogram (ECG) together, to prove the effect of H(2)S to the heart function. We also compared the heart infarct size and the expression of an anti-apoptosis gene, survivin, among groups. As the data shown, the NaHS group had great improvement in blood pressure and electrocardiogram situation. And the remarkable shrink of the infarct size and up-regulation of survivin in NaHS group comparing with the other two groups also showed the cardio protective effect of H(2)S in our study.


Assuntos
Cardiotônicos/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Sulfeto de Hidrogênio/sangue , Proteínas Associadas aos Microtúbulos/genética , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Sulfetos/uso terapêutico , Alcinos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Western Blotting , Cardiotônicos/administração & dosagem , Cardiotônicos/farmacocinética , Cistationina gama-Liase/antagonistas & inibidores , Cistationina gama-Liase/metabolismo , Modelos Animais de Doenças , Eletrocardiografia , Glicina/análogos & derivados , Glicina/farmacologia , Imuno-Histoquímica , Masculino , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/complicações , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/enzimologia , Miocárdio/patologia , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfetos/administração & dosagem , Sulfetos/farmacocinética , Survivina
17.
Wei Sheng Wu Xue Bao ; 47(4): 622-7, 2007 Aug.
Artigo em Zh | MEDLINE | ID: mdl-17944361

RESUMO

An actinomycete strain xjy was isolated from the soil of cotton field in Xinjiang against pathogenic fungus Fulvia fulva. The growth of 23 plant pathogens and 6 bacteria were strongly inhibitded by strain xjy on PDA plate. Antimicrobial spectrum of fermentation filtrate of strain xjy is extensive and selective to different pathogens. The morphology, cultural characteristics, physiological and biochemical properties, chemotaxonomy and 16S rDNA sequences of this strain were studied. The strain showed faint yellow vegetative mycelium, spiral spore-bearing filaments and column spores with smooth surface. No pigment was produced in culture. The cell wall type I and sugar type C showed the strain with streptomyces character. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the related species and showed 99.6% identity of nucleotide sequence of 16S rDNA with Streptomyces lavendulae. From the polyphasic taxonomical view, the strain xjy falls into Streptomyces lavendulae. The optimum fermentation condition of strain xjy for producing the most effective ferment filtrate were cultured in 2% soybean flour, 2% glucose, 0.8% NaCl, 0.2% CaCO3, 0.32% (NH4)2 SO4, the initial pH of 7.0, at 28 degrees C and shaked at 180r/mim for 6d. These results are valuable to strain application, antibiotics purification and its industrialization.


Assuntos
Antibiose , Ascomicetos/fisiologia , Fermentação , Doenças das Plantas/microbiologia , Microbiologia do Solo , Streptomyces/fisiologia , Filogenia , Streptomyces/classificação , Streptomyces/genética , Streptomyces/isolamento & purificação
18.
Ying Yong Sheng Tai Xue Bao ; 27(10): 3307-3315, 2016 Oct.
Artigo em Zh | MEDLINE | ID: mdl-29726158

RESUMO

Northeast China is one of the most important farming regions in China, due to its great contribution to national food security. Crop production is a main source of carbon emission. To assess the differences in carbon footprints of major grain crop production will benefit the achievement of low carbon agriculture. Therefore, this study calculated the regional carbon foot prints of rice (Oryza sativa), maize (Zea mays) and soybean (Glycine max) production in Northeast China du-ring 2004-2013 using the provincial statistical data, including crop yield, sown area and production inputs. The results showed that the highest area-scale carbon footprint was found in rice production, with the average value of (2463±56) kg CE·hm-2, while the second was found in maize production during 2004-2013. The sharpest rise occurred in maize production, from 1164 kg CE·hm-2 in 2004 to 1768 kg CE·hm-2 in 2013, with the average rate of 67 kg CE·hm-2·a-1. The application of chemical fertilizer contributed to the carbon footprint largely, accounting for 45%, 90% and 83% for rice, maize and soybean, respectively. Moreover, the contribution of electricity for irrigation in rice production ranged from 29% to 42%, which was larger than that in maize and soybean production. The carbon footprints were significantly different among the three provinces of Northeast China. The highest yield-scaled carbon footprints for three crops were found in Jilin Province, while the lowest area-scaled carbon footprints found in Heilongjiang Province. Given to the large transfer of rural labor from agricultural to non-agricultural sections and the development of mechanization, diesel and other mechanical inputs would increase rapidly in the future. Therefore, improving ferti-lizer utilization, mechanical and irrigation efficiencies in crop production would be the main approaches to promoting low-carbon agriculture in Northeast China.


Assuntos
Agricultura , Pegada de Carbono , Grão Comestível/crescimento & desenvolvimento , Carbono/análise , China , Fertilizantes , Oryza/crescimento & desenvolvimento , Glycine max/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimento
19.
J Phys Condens Matter ; 27(24): 245303, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26030722

RESUMO

The stability, elastic properties, and electronic structure of germanane nanoribbons (GeNRs) are studied from first-principles calculations. When using atomic H as the hydrogen source, a germanane monolayer spontaneously breaks into ribbons. GeNRs can be easily stretched due to their small in-plane stiffness, suggesting that it is feasible to modulate their properties by strain. All GeNRs show direct band gaps at the Γ point when external strain is zero, with the gap value decreasing with increasing ribbon width. When axial tensile strain is applied, the band gap decreases, and a direct-to-indirect gap transition occurs. The transition can be attributed to different deformation potentials of different states in the valence band. These results suggest potential applications of GeNRs in the fields of pressure sensors and tunable optical electronics.

20.
Int J Clin Exp Med ; 8(1): 472-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25785019

RESUMO

PURPOSE: To establish a classification system for the different types of posterior tibial plateau fractures (PTPF), and to explore the fracture patterns and early results of treatment. METHODS: 39 PTPFs patients who received surgeries through posteromedial or (and) posterolateral knee approaches were analyzed retrospectively. RESULTS: There were 5 types of PTPFs identified in the new classification system: posteromedial split fracture (type I, 7 patients), posterolateral split fracture (type II, 5 patients), posterolateral depression fracture (type III, 11 patients), posterolateral split and depression fracture (type IV, 2 patients), and posteromedial split combined with posterolateral depression fracture (type V, 14 patients). All patients underwent surgeries safely without complications. The average follow up was 18.1 months (12-30 months). The average weight-bearing durations were 15.6 weeks (12-20 weeks). Based on Rasmussen functional scoring system, 20 cases were regarded as excellent, 14 were good, 5 were fair, and 0 was poor. There was significant change in the Rasmussen functional score before (8.38 ± 2.87) and after surgery (24.20 ± 3.44). According to Rasmussen radiology system, 28 cases were excellent, 8 cases were good, 3 were fair, and none was poor. There was also a significant difference detected between pre-operation (6.77 ± 2.27) and post-operation (16.41 ± 2.65). CONCLUSION: This study presents a new classification system for the different types of PTPFs based on the treatment. The classification is clinically relevant and can be used to guide the surgical management.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA