Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Plant J ; 110(3): 899-915, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35106861

RESUMO

The phellem is a specialized boundary tissue providing the first line of defense against abiotic and biotic stresses in organs undergoing secondary growth. Phellem cells undergo several differentiation steps, which include cell wall suberization, cell expansion, and programmed cell death. Yet, the molecular players acting particularly in phellem cell differentiation remain poorly described, particularly in the widely used model plant Arabidopsis thaliana. Using specific marker lines we followed the onset and progression of phellem differentiation in A. thaliana roots and further targeted the translatome of newly developed phellem cells using translating ribosome affinity purification followed by mRNA sequencing (TRAP-SEQ). We showed that phellem suberization is initiated early after phellogen (cork cambium) division. The specific translational landscape was organized in three main domains related to energy production, synthesis and transport of cell wall components, and response to stimulus. Novel players in phellem differentiation related to suberin monomer transport and assembly as well as novel transcription regulators were identified. This strategy provided an unprecedented resolution of the translatome of developing phellem cells, giving a detailed and specific view on the molecular mechanisms acting on cell differentiation in periderm tissues of the model plant Arabidopsis.


Assuntos
Arabidopsis , Arabidopsis/genética , Câmbio/genética , Parede Celular , Regulação da Expressão Gênica de Plantas , Raízes de Plantas , Fatores de Transcrição/genética
2.
Zhongguo Zhong Yao Za Zhi ; 47(1): 85-94, 2022 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-35178914

RESUMO

With reference to the production process documented in Chinese Pharmacopoeia, this paper prepared the calibrator samples of Xiaochaihu Granules from multiple batches and established a method for fingerprint analysis and content determination that could be used to evaluate Xiaochaihu Granules available in market. Multiple batches of Chinese herbal pieces contained in Xiaochaihu Granules were collected for preparing the calibrator samples according to the process in Chinese Pharmacopoeia. Following the establishment of fingerprints for calibrator samples by UHPLC, the method for determining the contents of saikosaponin B2, saikosaponin B1, baicalin, wogonoside, baicalein, liquiritin, glycyrrhizin G2 and glycyrrhizic acid in Xiaochaihu Granules was established. The experimental results showed that the fingerprints of calibrator samples had 26 common peaks, covering the chemical compounds of main herbs Bupleuri Radix, Scutellariae Radix, Changii Radix, Glycyrrhizae Radix et Rhizoma, and Rhizoma Zingiberis Recens. The similarity of fingerprints for 47 batches of Xiaochaihu Granules from 31 companies with the calibrator sample fingerprint ranged from 0.74 to 0.99, indicating good applicability of the established fingerprint. The contents of main components baicalin, saikosaponin B2, and glycyrrhizic acid in Xiaochaihu Granules were within the ranges of 22.917-49.108 mg per bag(RSD 19%), 0.28-2.19 mg per bag(RSD 62%), and 0.897-6.541 mg per bag(RSD 41%), respectively. The quality difference in saikosaponin B2, and glycyrrhizic acid among different manufacturers was significant. The fingerprint analysis and content determination method for calibrator samples of Xiaochaihu Granules prepared according to the production process in Chinese Pharmacopoeia has been proved suitable for evaluating the quality of Xiaochaihu Granules from different manufacturers. Saikosaponin B2, glycyrrhizic acid, and liquiritin should be added as content control indicators for Xiaochaihu Granules, aiming to further improve the product quality.


Assuntos
Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Ácido Glicirrízico/análise , Rizoma/química , Scutellaria baicalensis
3.
Zhongguo Zhong Yao Za Zhi ; 46(8): 2016-2019, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33982514

RESUMO

In leading the high-quality development of Chinese medicine preparations, it is an important link to formulate the scientific, reasonable, and feasible guidelines for the change of Chinese medicines in accordance with the change characteristics and principles of the Chinese medicines is an important work to promote the Technical guidelines for the study of pharmaceutical changes in traditional Chinese medicines was formed by a broad consensus based on the characteristics and research results of the pharmaceutical changes in Traditional Chinese Medicines(TCM)with the principles of science and risk management. This guideline has clarified the basic principles and requirements for the evaluation of changes in TCM, specified the research and verification work of common change scenarios, defined the boundaries of changes in TCM, and proposed to encourage the use of new technologies, new methods, and new excipients that meet product characteristics. It will definitely promote the quality improvement and the secondary development of TCM. In this article, the revision background and main content of the guideline were introduced, and the main features of the Guideline were analyzed, in order to provide references for the industry.


Assuntos
Medicamentos de Ervas Chinesas , Preparações Farmacêuticas , Consenso , Composição de Medicamentos , Medicina Tradicional Chinesa , Melhoria de Qualidade
4.
Zhongguo Zhong Yao Za Zhi ; 45(18): 4285-4290, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33164354

RESUMO

Pudilan Xiaoyan Oral Liquid is widely used in clinical applications, with safe and effective results. Its coverage rate in the national first, second and third grade hospitals is as high as 71%. In this study, we analyzed and summarized the research progress on the material basis, quality control, production process and clinical medication of Pudilan Xiaoyan Oral Liquid based on the clinical diseases(parotitis, tonsillitis, pharyngitis), and deeply explored the intrinsic quality improvement and secondary development of Pudilan product. Pharmacodynamic material basis of Pudilan Xiaoyan Oral Liquid was explored through the network pharmacology technology and quality control indicators of the production process were optimized by cell anti-inflammatory experiments. Through these techno-logies, it would be more specific, scientific and effective to carry out process optimization of each link and multidimensional quality control of the whole process. The dosage and oral compliance for special patients(children) were explored, providing a reference for clinical pediatric medication of Pudilan Xiaoyan Oral Liquid. Simultaneously, it is helpful to expand the application market by developing Pudilan daily chemical products, and promote the traditional Chinese medicine products in terms of curative effect and daily life.


Assuntos
Medicamentos de Ervas Chinesas , Faringite , Anti-Inflamatórios , Criança , Humanos , Medicina Tradicional Chinesa
5.
Zhongguo Yi Liao Qi Xie Za Zhi ; 44(3): 194-198, 2020 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-32621424

RESUMO

In order to evaluate the biomechanical stability of titanium alloy screw with different structural parameters under bone remodeling, some three-dimensional finite element models were established and the bone remodeling process after implanting the screw was simulated. Three-dimensional finite element models consist of bone and screw with different lengths and diameters. Bone remodeling process was simulated by user-defined subroutine. It is found that the stress on the bone is concentrated on the groove and root of the internal thread. The screw stress is mainly on the beginning of the thread, and the whole stress decreases along the long axis of the screw. The stress distribution trend of bone and screw did not change significantly during the bone remodeling. The maximum equivalent stress value was different, the maximum equivalent stress on the screw and cancellous bone increased while the maximum equivalent stress value on the cortical bone decreased.


Assuntos
Remodelação Óssea , Parafusos Ósseos , Fenômenos Biomecânicos , Análise de Elementos Finitos , Estresse Mecânico , Titânio
6.
Zhongguo Zhong Yao Za Zhi ; 44(13): 2736-2741, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31359684

RESUMO

Astragali Radix( AR) polysaccharide for injection( Guoyao Zhunzi Z20040086) is a traditional Chinese medicine for intravenous powder injection developed by Shanxi Academy of Traditional Chinese Medicine in early 1990 s by taking advantage of AR resources in Shanxi province. The effective parts of AR polysaccharides were obtained by advanced technology. The hemogram of patients with radiotherapy and chemotherapy showed alleviations in clinic. However,due to the technical bottleneck in separation of the complex polysaccharides mixture and the difficulties in accurate measurement of the polysaccharide structures,the pharmacodynamic mechanism of the drug remained unclear,and the side effect was hard to control. In recent years,the theoretical studies for polysaccharide receptors have indicated that when polysaccharides bound to protein receptors,only the oligosaccharide fragments of the polysaccharide molecule bound to the receptors,and one or more active sites of oligosaccharide fragments may existed in the polysaccharide molecule.Therefore,the active center of polysaccharides can be studied based on the level of oligosaccharides through degradation of the polysaccharides,which provided a new strategy for breaking through the bottleneck in polysaccharide structure determination. Therefore,this paper reviews the current status of studies for AR polysaccharides for injection,the polysaccharide receptors theory and successful cases,in order to propose the secondary development ideas of AR polysaccharides for injection. The study results will lay a material foundation for the development of new drugs of polysaccharides from traditional Chinese medicine,and provide a basis for the resolution of international difficulties in quality control of polysaccharide drugs and molecular models,so as to further study of glycobiology,and enrich the polysaccharide receptors theory.


Assuntos
Astrágalo/química , Medicamentos de Ervas Chinesas , Raízes de Plantas/química , Polissacarídeos/farmacologia , Humanos , Medicina Tradicional Chinesa
7.
New Phytol ; 215(2): 642-657, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28609015

RESUMO

Plant secondary growth derives from the meristematic activity of the vascular cambium. In Arabidopsis thaliana, cell divisions in the cambium are regulated by the transcription factor WOX4, a key target of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (ESR)-RELATED 41 (CLE41) signaling pathway. However, function of the WOX4-like genes in plants that are dependent on a much more prolific secondary growth, such as trees, remains unclear. Here, we investigate the role of WOX4 and CLE41 homologs for stem secondary growth in Populus trees. In Populus, PttWOX4 genes are specifically expressed in the cambial region during vegetative growth, but not after growth cessation and during dormancy, possibly involving a regulation by auxin. In PttWOX4a/b RNAi trees, primary growth was not affected whereas the width of the vascular cambium was severely reduced and secondary growth was greatly diminished. Our data show that in Populus trees, PttWOX4 genes control cell division activity in the vascular cambium, and hence growth in stem girth. This activity involves the positive regulation of PttWOX4a/b through PttCLE41-related genes. Finally, expression profiling suggests that the CLE41 signaling pathway is an evolutionarily conserved program for the regulation of vascular cambium activity between angiosperm and gymnosperm tree species.


Assuntos
Câmbio/citologia , Proteínas de Plantas/metabolismo , Populus/crescimento & desenvolvimento , Populus/genética , Câmbio/genética , Câmbio/crescimento & desenvolvimento , Divisão Celular , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Filogenia , Células Vegetais , Proteínas de Plantas/genética , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Populus/citologia
8.
Heliyon ; 10(16): e35922, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39220974

RESUMO

There are still problems such as low standardization and low interoperability in the prefabricated building precast component design with BIM technology, which lead to the absence and separation of precast components in the deepening design stage and other stages. Therefore, how to solve the problem of mutual loss and separation among the various levels of the precast component deepening design process has become one of the key problems to be urgently resolved. To link up each stage of the deepening design and improve its efficiency. Based on semi-structured interview, the primary and secondary functional modules required for the detailed design of precast components were clarified. Based on C# programming language and Revit API, the Revit API-based the design platform for deepening precast components (DPDPC) of prefabricated buildings was independently developed by using secondary development technology. Based on the research method of case analysis, this paper uses the DPDPC to study and demonstrate the actual project, and finally verifies the feasibility of the precast component deepening design process. The research results show that, the prototype of the DPDPC constructed includes three first-level function modules and eleven second-level function modules. The detailed design process of precast components with Revit as the core is component split → component design → optimized design → component drawing → material list. This paper provides clarity on the main process of precast deepening design. The prototype of DPDPC constructed not only helps to better connect each level of prefabricated building precast component deepening design, but also helps to display the functional requirements of each level of deepening design process through a systematic platform from the technical level. To provide a reference for further design of precast components.

9.
Micromachines (Basel) ; 15(4)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38675251

RESUMO

Aluminum alloy 6082-T6 is an important material for manufacturing the outer skin of high-speed trains, and laser shock forming can realize the rapid forming of complex-shaped plates. In order to improve the efficiency of the simulation modeling of laser shock forming for aluminum alloy 6082-T6, Python scripting language was used for the secondary development of Abaqus. A plugin was utilized to simulate and analyze the laser shock forming process of aluminum alloy 6082-T6. The coordinates of the plate after laser impact molding were measured using a coordinate measuring machine to calculate the arc bow height of the plate. The accuracy of the simulation model was verified by comparing with the simulation results. The deformation characteristics of plastic strain and arc height of aluminum alloy 6082-T6 under different laser process parameters were analyzed. The simulation plugin has a concise interface, high operability, and accurate results with the other parameters unchanged. When the laser energy is 5 J, 6 J, and 7 J, the corresponding arc heights are 5.9 mm, 6.6 mm, and 7.2 mm, respectively. As the thickness of the sheet increases, the deformation changes from concave at 1 mm to convex at 2 mm, 3 mm, 4 mm, and 5 mm. As the spot size increases from 1 mm to 5 mm, the transmission mode of the shock wave gradually changes from spherical wave to planar wave, and the arc height of the sheet increases from 4.6 mm to 8.2 mm. With the increase in the spot overlap rate, the impact area accumulates residual stress, and the arc height of the sheet is 5.7 mm, 6.6 mm, 7.3 mm, and 8.5 mm, respectively. The secondary development of ABAQUS 2021 using Python 3.6 scripting language has improved the efficiency of simulation modeling and provided reference for rapidly predicting the deformation characteristics of aluminum alloy 6082-T6 under different laser process parameters.

10.
Chin Med ; 18(1): 45, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37098552

RESUMO

Shufeng Jiedu Capsule (SFJDC), composed of eight herbs, is a big brand traditional Chinese medicine (TCM) for the treatment of different respiratory tract infectious diseases with good clinical efficacy and few side effects. It is clinically applied to acute upper respiratory tract infection(URI), influenza, acute exacerbation of chronic obstructive pulmonary disease (AECOPD), community-acquired pneumonia(CAP) and other diseases, due to its antibacterial, antiviral, anti-inflammatory, immunoregulatory and antipyretic activities. In particular, it has shown good clinical effects for COVID-19, and was included in the fourth to tenth editions of the 'Diagnosis and Treatment Protocol for COVID-19 (Trial)' by the National Health Commission. In recent years, studies on the secondary development which focus on the basic and clinical application of SFJDC have been widely reported. In this paper, chemical components, pharmacodynamic material basis, mechanisms, compatibility rule and clinical application were systematically summarized, in order to provide theoretical and experimental basis for further research and clinical application of SFJDC.

11.
Cells ; 11(15)2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35954186

RESUMO

The simultaneous occurrence of heat stress and drought is becoming more regular as a consequence of climate change, causing extensive agricultural losses. The application of either heat or osmotic stress increase cell-wall suberization in different tissues, which may play a role in improving plant resilience. In this work, we studied how the suberization process is affected by the combination of drought and heat stress by following the expression of suberin biosynthesis genes, cell-wall suberization and the chemical composition in Arabidopsis roots. The Arabidopsis plants used in this study were at the onset of secondary root development. At this point, one can observe a developmental gradient in the main root, with primary development closer to the root tip and secondary development, confirmed by the suberized phellem, closer to the shoot. Remarkably, we found a differential response depending on the root zone. The combination of drought and heat stress increased cell wall suberization in main root segments undergoing secondary development and in lateral roots (LRs), while the main root zone, at primary development stage, was not particularly affected. We also found differences in the overall chemical composition of the cell walls in both root zones in response to combined stress. The data gathered showed that, under combined drought and heat stress, Arabidopsis roots undergo differential cell wall remodeling depending on developmental stage, with modifications in the biosynthesis and/or assembly of major cell wall components.


Assuntos
Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Parede Celular/metabolismo , Lipídeos/fisiologia , Pressão Osmótica/fisiologia , Raízes de Plantas/metabolismo , Plantas
12.
Front Plant Sci ; 13: 1006153, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36247566

RESUMO

Periderm protects enlarged organs of most dicots and gymnosperms as a barrier to water loss and disease invasion during their secondary growth. Its development undergoes a complex process with genetically controlled and environmental stress-induced characters. Different development of periderm makes the full and partial russet of fruit skin, which diverges in inheritance with qualitative and quantitative characters, respectively, in pear pome. In addition to its specific genetics, fruit periderm has similar development and structure as that of stem and other organs, making it an appropriate material for periderm research. Recently, progress in histochemical as well as transcriptome and proteome analyses, and quantitative trait locus (QTL) mapping have revealed the regulatory molecular mechanism in the periderm based on the identification of switch genes. In this review, we concentrate on the periderm development, propose the conservation of periderm regulation between fruit and other plant organs based on their morphological and molecular characteristics, and summarize a regulatory network with the elicitors and repressors for the tissue development. Spontaneous programmed-cell death (PCD) or environmental stress produces the original signal that triggers the development of periderm. Spatio-temporal specific PCD produced by PyPPCD1 gene and its homologs can play a key role in the coordinated regulation of cell death related tissue development.

13.
Environ Sci Pollut Res Int ; 29(36): 55003-55025, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35314931

RESUMO

In the process of exploiting mineral resources, dust enters the environment through air suspended particles and surface runoff, which has a serious impact on the atmospheric environment and human health. From all-year and seasonal scenarios, the migration trajectories and cumulative concentration based on the secondary development of Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) in four mining areas (SF, BC, SJZ, and MJT) in Northwest China are studied. The convergent cross mapping (CCM) method is used to study the causal relationship between concentration and meteorological factors. In this process, the problem of missing non-station meteorological data is solved with the help of the inverse distance weighted interpolation method, and the problem in which the convergence requirements of the CCM algorithm cannot meet the requirements is solved with the bootstrap method. The results indicated that the short path has the characteristics of slow movement, short migration path, low altitude(< 1 km), and high contribution rate, while the long path has the opposite characteristics. Furthermore, the results demonstrated that the concentration is centered on the pollution source and diffuses around, with a diffusion radius of 220-270 km, showing a serious pollution center and slight gradient settlement on the edge, but the overall distribution of accumulated concentration is uneven. The results also show that temperature (TEMP and S_TEMP), evaporation, and air pressure are the main meteorological factors affecting the all-year concentration. The concentration and meteorological factors in the four mining areas also show significant seasonal characteristics, and the correlation in spring, summer, and autumn is stronger than that in winter. This study not only provides a reference for the green and sustainable exploitation of mineral resources but also provides theoretical support for the joint prevention and control of transboundary pollution.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental/métodos , Humanos , Conceitos Meteorológicos , Meteorologia , Material Particulado/análise , Estações do Ano
14.
Artigo em Inglês | MEDLINE | ID: mdl-36497994

RESUMO

The long-term stability of coal mine roadway engineering is critical to the safe mining of coal resources and the protection of the surface environment. In this paper, the creep test of coal samples in coal roadway was carried out by multi-stage constant load method, and the test results showed that when the stress level was low, the creep curve had a attenuated stage and a steady-state stage, and the steady-state creep rate tended to increase with the increase in the stress level; When the stress level was higher than the yield stress, the creep rate curve appeared to have an acceleration stage after the steady-state stage. The instability failure mode of the coal sample was mainly shear failure with local tension failure. For this, a New Fractional-order Nonlinear Viscoelastic-plastic Rheological Model (NFNVRM) was established by introducing Abel elements and Nonlinear elements, and the constitutive equation of the model was deduced. The new model can fully reflect the stable decay stage and accelerated rheological stages of coal samples, and the parameter identification curve was consistent with the experimental results, which verifies the correctness and reasonableness of the NFNVRM. Meanwhile, based on the FLAC3D secondary development interface, the constitutive equations of the NFNVRM were written into the software to obtain new Dynamic Link Library (DLL) files. The simulation results were consistent with the experimental results when the DLL file was called. Finally, the NFNVRM.dll was applied to predict the surrounding rock deformation of an S mine. The study's findings offer suggestions for environmental protection.


Assuntos
Minas de Carvão , Carvão Mineral , Mineração , Engenharia , Minas de Carvão/métodos
15.
Materials (Basel) ; 14(6)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803860

RESUMO

In the rolling process of heavy cylinders, the deformation section is subjected to the effects of compression and shear. In order to analyze the influences of the shear effect on the microstructure evolution characteristics, a mathematical model was established and the rolling process was simulated. Firstly, shear-compression specimen (SCS) and ordinary cylinder specimens were designed, high-temperature compression experiments were carried out and the mathematical model of microstructure evolution considering shear effect was established; then, a program based on finite element software was developed to simulate the microstructure evolution process, and the feasibility of the development program was verified by compression experiments. Finally, a macro-micro coupling model based on the development program was established to simulate the microstructure evolution of the heavy cylinder during the rolling process. Then, the influence of the shear effect on the microstructure evolution was analyzed. The results showed that the shear effect had a great influence on the heavy cylinder. Dynamic recrystallization was more likely to occur in the heavy cylinder during the rolling process and the grain refinement was more obvious; compared with the case without considering the shear effect, the volume fraction of dynamic recrystallization was increased by 0.25%, and the grain size was refined by 30 µm.

16.
Materials (Basel) ; 12(13)2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31284693

RESUMO

The high-temperature deformation behavior of Q345 steel is detected by a Gleeble-3800 thermal simulator. The Arrhenius constitutive equation for high-temperature flow stress and the dynamic recrystallization model are constructed. With the secondary development technology, customized modifications are made on existing Deform-3D software. The constructed constitutive model and dynamic recrystallization model are embedded into Deform-3D to realize the secondary development of Deform-3D. The grain size and volume percentage distribution of dynamic recrystallization are obtained by simulating the shear connection process at high temperature and high speed. The results show that the constitutive equation and the dynamic recrystallization model constructed in this paper can be used to predict the evolution of the microstructure. The difference between the prediction results and the experimental data is about 3%. The accuracy of Arrhenius constitutive equation, dynamic recrystallization model and the feasibility of software secondary development are verified.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA