Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 169
Filtrar
1.
Chempluschem ; : e202400192, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38979961

RESUMO

A three-dimensional (3D) anionic cadmium-organic framework, namely [(CH3)2NH2][Cd1.5(DMTDC)2] ⋅ 2DMA ⋅ 0.5H2O (Cd-MOF; DMA=N,N-dimethylacetamide), was successfully synthesized under solvothermal conditions by using a linear thienothiophene-containing dicarboxylate ligand, 3,4-dimethylthieno [2,3-b]-thiophene-2,5-dicar-boxylic acid (H2DMTDC). Single-crystal X-ray diffraction analysis reveals that Cd-MOF exhibits a 3D anionic framework with pcu α-Po topology, featuring rectangle and rhombus-shaped channels along b- and c- axis direction. Cd-MOF demonstrates selective adsorption of cationic dyes over anionic and neutral dyes. Additionally, Tb3+-loaded Cd-MOF serves as a fast-response fluorescence sensor for the sensitive detection of Fe3+ ions with a low limit of detection (8.90×10-7 M) through fluorescence quenching.

2.
Public Health Nutr ; 27(1): e118, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38600858

RESUMO

OBJECTIVE: This study aimed to evaluate the methodological quality of existing meta-analyses (MA) and the quality of evidence for outcome indicators to provide an updated overview of the evidence concerning the therapeutic efficacy of the Mediterranean diet (MD) for various types of CVD. DESIGN: We conducted comprehensive searches of PubMed, Cochrane Library, and Embase databases. The quality of the MA was assessed using the A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) checklist, while the Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence evaluation system was employed to evaluate the quality of evidence for significant outcomes. SETTING: The CVD remains a significant contributor to global mortality. Multiple MA have consistently demonstrated the efficacy of medical interventions in managing CVD. However, due to variations in the scope, quality and outcomes of these reviews, definitive conclusions are yet to be established. PARTICIPANTS: This study included five randomized trials and twelve non-randomized studies, with a combined participant population of 716 318. RESULTS: The AMSTAR 2 checklist revealed that 54·55 % of the studies demonstrated high quality, while 9·09 % exhibited low quality, and 36·36 % were deemed critically low quality. Additionally, there was moderate evidence supporting a positive correlation between MD and CHD/acute myocardial infarction, stroke, heart failure, cardiovascular events, coronary events and major adverse cardiovascular events. CONCLUSIONS: This study indicates that although recognizing the potential efficacy of MD in managing CVD, the quality of the methodology and the evidence for the outcome indicators remain unsatisfactory.


Assuntos
Doenças Cardiovasculares , Dieta Mediterrânea , Humanos , Doenças Cardiovasculares/prevenção & controle , Dieta Mediterrânea/estatística & dados numéricos
3.
J Colloid Interface Sci ; 665: 133-143, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38520930

RESUMO

Anion exchange membranes (AEMs) are the heart of alkaline fuel cells and water electrolysis, and have made a great progress in recent years. However, AEMs are still unable to satisfy the needs of high conductivity and stability, hindering their widespread commercialization. Side chain regulations have been widely used to prepare highly conductive and durable AEMs. Here, we construct a series of polyaromatic AEMs grafted with fluorinated cation side chains and cation-free alkyl chains with different end groups to explore the polar discrimination of side chains on membrane performance. This work demonstrates that AEMs grafting the cation side chains with superhydrophobic fluorine pendent and alkyl side chains with hydrophilic pendent enhance water content and ion conductivity. This is due to the strong immiscibility between the hydrophilic and hydrophobic head groups which promotes the establishments of microphase separation and ion highways. Specifically, poly(binaphthyl-co-terphenyl piperidinium) containing fluorinated piperidinium side chains and alkyl chains with methoxy pendent (QBNTP-QFM) possesses a satisficed OH- conductivity (170.6 mS cm-1 at 80 °C) and can tolerate 5 M hot NaOH for 2100 h with only 3.4 % conductivity loss. Expectedly, the single cell with QBNTP-QFM yields a prominent maximum power density of 1.62 W cm-2 and the water electrolysis cell with QBNTP-QFM achieves a pronounced current density of 3.0 A cm-2 at 1.8 V, both cells also display a prominent durability for 120 h operation. The results prove that this side chain optimization can improve ion conductivity and is a promising method for AEM development.

5.
Chem Commun (Camb) ; 59(91): 13651-13654, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37905986

RESUMO

An organic-inorganic hybrid ferroelectric, (C6H5CH2CH2NH3)2[HgI4], undergoes an exceptional structural phase transition near room temperature, triggered by a flip of half the organic cations and an order-disorder transition of the inorganic anions, and may be regarded as a displacive-type ferroelectric. This finding provides a new structural phase transition mechanism in molecule-based ferroelectrics.

6.
J Colloid Interface Sci ; 651: 404-414, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37549525

RESUMO

Anion exchange membrane fuel cells (AEMFCs), which are more economical than proton exchange membrane fuel cells (PEMFCs), stand out in the context of the rapid development of renewable energy. Superacid-catalyzed ether-free aromatic polymers have recently received a lot of attention due to their exceptional performance, but their development has been hampered by the trade-off between the dimensional stability and ionic conductivity of anion exchange membranes (AEMs). Here, we introduced fluoroketones containing different numbers of fluorinated groups (x = 0, 3 and 6) in the main chain of p-terphenyl piperidine because of the favorable hydrophobic properties of fluorinated groups. The results show that fluorinated AEMs can enhance OH- conductivity by building more aggregated hydrophilic channels while ensuring dimensional stability. The PTF6-QAPTP AEM with more fluorinated groups has the most excellent performance at 80 °C with an OH- conductivity of 142.7 mS cm-1 and a swelling ratio (SR) of only 4.55 %. Additionally, it exhibits good alkali durability, with the OH- conductivity and quaternary ammonium (QA) cation retaining at 93.45% and 92.6%, respectively, after immersion in a 2 M NaOH solution at 80 °C for 1200 h. In addition, the power density of the PTF6-QAPTP based single cell reaches 849 mW cm-2 when the current density is 1600 mA cm-2. The PTF6-QAPTP based cell has a voltage retention of 88% after 80 h of stability testing at a constant current density of 300 mA cm-2 at 80 °C.

7.
Opt Express ; 31(12): 20160-20173, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37381416

RESUMO

A scheme of nonreciprocal conventional phonon blockade (PB) is proposed in a spinning optomechanical resonator coupled with a two-level atom. The coherent coupling between the atom and breathing mode is mediated by the optical mode with a large detuning. Due to the Fizeau shift caused by the spinning resonator, the PB can be implemented in a nonreciprocal way. Specifically, when the spinning resonator is driven from one direction, the single-phonon (1PB) and two-phonon blockade (2PB) can be achieved by adjusting both the amplitude and frequency of the mechanical drive field, while phonon-induced tunneling (PIT) occurs when the spinning resonator is driven from the opposite direction. The PB effects are insensitive to cavity decay because of the adiabatic elimination of the optical mode, thus making the scheme more robust to the optical noise and still feasible even in a low-Q cavity. Our scheme provides a flexible method for engineering a unidirectional phonon source with external control, which is expected to be used as a chiral quantum device in quantum computing networks.

8.
Dalton Trans ; 52(24): 8198-8203, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37283185

RESUMO

A new 2D flexible cobalt(II) framework (Co-MOF) exhibits a reversible solid-state structural transformation upon guest molecule removal/uptake. After activation, Co-MOF-α with 1D porous channels transformed into Co-MOF-ß (0D voids) accompanied by a shift in metal and carboxylate coordination modes, the rotation of organic linkers and the contraction of interstitial spaces. Gas adsorption experiments reveal that Co-MOF-ß exhibits a two-step CO2 adsorption isotherm and close-to-open (type F-IV) isotherms for C2H2, C2H4 and C2H6 at 195 K. Moreover, it shows typical type I adsorption isotherms for the above gases and the selective uptake of C2H2 over CH4 and CO2 at room temperature.

9.
Sci Rep ; 13(1): 7149, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37130872

RESUMO

Major outbreaks of influenza virus occurred in China in 2017-2018. To describe the pattern of influenza circulation and timing of seasonal epidemics, we analyzed data from influenza-like illness (ILI) specimens on surveillance wards of sentinel hospitals during 2014-2018. Among 1,890,084 ILI cases, 324,211 (17.2%) tested positive for influenza. Influenza A virus (particularly A/H3N2), which circulates annually, was detected in 62% of cases, compared with influenza B virus in 38% of cases. The detection rate of A/H1N1, A/H3N2, B/Victoria, and B/Yamagata viruses were 3.56%, 7.07%, 2.08%, and 3.45%, respectively. Influenza prevalence was generally stable over the four years analyzed, but obvious outbreaks occurred in 2015-2016 (17.28%) and 2017-2018 (22.67%), with B/Victoria and B/Yamagata contributing to these outbreaks, respectively. In the south, a characteristic peak in infections was detected in the summer (week 23-38), which was not detected in the north. Influenza B was found high frequency in school-age children (5-14 years) with 4.78% of B/Victoria and 6.76% of B/Yamagata. Therefore, the epidemiological characteristics of seasonal influenza were complex in China during 2014-2018, presenting distinctions in region, season, and susceptible population. These findings underline the importance of enhancing year-round influenza surveillance and provide a reference for the timing and variety of influenza vaccination.


Assuntos
Herpesvirus Cercopitecino 1 , Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Criança , Humanos , Pré-Escolar , Adolescente , Influenza Humana/epidemiologia , Estações do Ano , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza B , China/epidemiologia
10.
J Colloid Interface Sci ; 643: 62-72, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37044014

RESUMO

Anion exchange membrane fuel cells (AEMFCs) have emerged as a promising alternative to proton exchange membrane fuel cells (PEMFCs) due to their adaptability to low-cost stack components and non-noble-metals catalysts. However, the poor alkaline resistance and low OH- conductivity of anion exchange membranes (AEMs) have impeded the large-scale implementation of AEMFCs. Herein, the preparation of a new type of AEMs with crown ether macrocycles in their main chains via a one-pot superacid catalyzed reaction was reported. The study aimed to examine the influence of crown ether cavity size on the phase separation structure, ionic conductivity and alkali resistance of anion exchange membranes. Attributed to the self-assembly of crown ethers, the poly (crown ether) (PCE) AEMs with dibenzo-18-crown-6-ether (QAPCE-18-6) exhibit an obvious phase separated structure and a maximum OH- conductivity of 122.5 mS cm-1 at 80 °C (ionic exchange capacity is 1.51 meq g-1). QAPCE-18-6 shows a good alkali resistance with the OH- conductivity retention of 94.5% albeit being treated in a harsh alkali condition. Moreover, the hydrogen/oxygen single cell equipped with QAPCE-18-6 can achieve a peak power density (PPD) of 574 mW cm-2 at a current density of 1.39 A cm-2.

11.
Front Public Health ; 11: 1036823, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36761141

RESUMO

Objectives: To assess and evaluate the knowledge of Shanghai, China, residents on the use of SARS-CoV-2 antigen detection and rapid diagnostic self-test. Methods: A cross-sectional electronic survey using a self-administered questionnaire was sent via the online platform, Sojump, to general individuals. Multiple linear regression analysis was performed to determine the variables associated with knowledge of self-test. Results: A total of 283 participants were recruited between July 1, 2022 and July 20, 2022 through an online survey. The mean score of knowledge on the tests was 14.33 ± 2.85 (out of 21). The questions concerning the depth of swab insertion and minimum number of swab rotations in the nostril, necessity of bilateral sampling, necessity of rotating and squeezing the swab for 10 times in the extraction buffer tube, and waiting time for the results showed the highest rate of incorrect responses. In the multiple regression analysis model, sex, social status, and source of information were associated with the knowledge on the self-test kits. Conclusion: Immediate health education programs should be made available and the kits could be improved appropriately to ensure adequate knowledge. The use of technology should be fully leveraged to achieve accurate self-diagnosis and correct interpretation of the results.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , Testes de Diagnóstico Rápido , Estudos Transversais , Autoteste , China , Teste para COVID-19
12.
IEEE Trans Nanobioscience ; 22(1): 45-51, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35130165

RESUMO

Long-range surface plasmon resonance (LRSPR) sensors have been extensively studied by virtue of their extremely narrow full width at half maxima (FWHM) characteristics, but their low sensitivity remains an important factor limiting the figure of merit (FOM), making the sensors have difficulties in detecting small refractive index changes accurately. To address this problem, this paper proposes and demonstrates a low dimensional nanostructure (Au nanospheres, WS2) assisted LRSPR sensor to achieve an effective enhancement of the sensor interfaced electric field and thus improve the sensitivity. The performance parameters of the two sensors are compared with the LRSPR sensor by finite element method analysis, and the results showed that the assistance of the low dimensional nanostructure has a positive effect on the sensor. The first refractive index sensing experiment of the WS2-assisted LRSPR sensor was realized with a 25.47% increase in sensitivity and a 7.13% increase in FOM simultaneously, and the Au nanospheres-assisted LRSPR sensor with a 29.23% increase in sensitivity and a 15.95% increase in FOM simultaneously. The introduction of low dimensional nanostructures provides a flexible and effective means of sensitization for LRSPR sensors, making the plasmon resonance sensors combine high sensitivity, narrow FWHM and high FOM, which have promising applications in biochemical sensing.


Assuntos
Nanoestruturas , Ressonância de Plasmônio de Superfície , Ressonância de Plasmônio de Superfície/métodos , Refratometria
13.
J Colloid Interface Sci ; 634: 110-120, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36535151

RESUMO

In order to realise high ionic conductivity and improved chemical stability, a series of anion exchange membranes (AEMs) with semi-interpenetrating polymer network (sIPN) has been prepared via the incorporation of crosslinked poly(biphenyl N-methylpiperidine) (PBP) and spirobisindane-based intrinsically microporous poly(ether ketone) (PEK-SBI). The formation of phase separated structures as a result of the incompatibility between the hydrophilic PBP network and the hydrophobic PEK-SBI segment, has successfully promoted the hydroxide ion conductivity of AEMs. A swelling ratio (SR) as low as 12.2 % at 80 °C was recorded for the sIPN containing hydrophobic PEK-SBI as the linear polymer and crosslinked structure with a mass ratio of PBP to PEK-SBI of 90/10 (sIPN-90/10(PEK-SBI)). The sIPN-90/10(PEK-SBI) AEM achieved the highest hydroxide ion conductivity of 122.4 mS cm-1 at 80 °C and a recorded ion exchange capacity (IEC) of 2.26 meq g-1. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) clearly revealed the improved phase separation structure of sIPN-90/10(PEK-SBI). N2 adsorption isotherm indicated that the Brunauer-Emmett-Teller (BET) surface area of the AEMs increased with the increase of microporous PEK-SBI content. Interestingly, the sIPN-90/10(PEK-SBI) AEM showed good alkaline stability for being able to maintain a conductivity of 94.7 % despite being soaked in a 1 M sodium hydroxide solution at 80 °C for 30 days. Meanwhile, a peak power density of 481 mW cm-2 can be achieved by the hydrogen/oxygen single cell using sIPN-90/10(PEK-SBI) as the AEM.


Assuntos
Éter , Etil-Éteres , Éteres , Ânions , Cetonas
14.
J Colloid Interface Sci ; 629(Pt A): 377-387, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36087553

RESUMO

Poly(aryl piperidinium) (PAP) anion exchange membranes (AEMs) furnish an important avenue for the commercialization of anion exchange membrane fuel cells (AEMFCs), but their ionic conductivity and alkali resistance still need to be improved. Here, we report the synthesis of PAP AEMs with a branched structure by the acid-catalyzed reaction and compare them with the main-chain AEMs. The experimental results show that the branched AEMs have higher OH- conductivity and alkaline resistance than the poly(terphenyl piperidine) (PTPQ1) AEM. The alkaline stability and OH- conductivity of the AEMs were further improved by a flexible multi-cation crosslinker. The results show that the branched poly(p-terphenyl triphenylmethane 1-methyl piperidine) membrane crosslinked by multi-cation (PTTPQ4-40) shows an excellent OH- conductivity (155.3 mS cm-1) at 80 °C. The OH- conductivity of the PTTPQ4-40 membrane was maintained at 92.1% after soaking in 2 M NaOH for 1080 h at 80 °C. In addition, the peak power density (PPD) of the crosslinked PTTPQ4-40 membrane can reach 656.7 mW cm-2. Compared to the PTPQ1 AEM, the PPD of the crosslinked PTTPQ4-40 AEM is increased by 38.6% in H2-O2. All of the results confirm that the PTTPQ4-40 AEM has excellent fuel cell application prospects.

15.
IUCrdata ; 7(Pt 4): x220377, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36337687

RESUMO

In the title compound, [NiCl2(C20H18N4)2] n , the Ni2+ cation is situated on an inversion center and is coordinated by two chloride ions and four imidazole N atoms of four different 4,4'-bis-[(1H-imidazol-1-yl)meth-yl]-1,1'-biphenyl (BIMB), forming a slightly distorted octa-hedral geometry. Each BIMB ligand adopts a linear linker to connect Ni2+ ions, forming a two-dimensional layer with an sql network. In the crystal, neighboring layers repeat in an ABAB stacking mode, and weak inter-molecular C-H⋯Cl hydrogen bonds between alternate layers lead to a three-dimensional, twofold inter-penetrated, supra-molecular framework with a pcu topology net.

16.
Plants (Basel) ; 11(19)2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36235396

RESUMO

Grain shape and size are key determinants of grain appearance quality and yield in rice. In our previous study, a grain shape QTL, qGS1-35.2, was fine-mapped using near-isogenic lines (NILs) derived from a cross between Zhenshan 97 (ZS97) and Milyang 46 (MY46). One annotated gene, OsPUB3, was found to be the most likely candidate gene. Here, knockout and overexpression experiments were performed to investigate the effects of OsPUB3 on grain shape and size. Four traits were tested, including grain length, grain width, grain weight, and the ratio of grain length to width. Knockout of OsPUB3 in NILZS97, NILMY46, and another rice cultivar carrying the OsPUB3MY46 allele all caused decreases in grain width and weight and increases in the ratio of grain length to width. Results also showed that the magnitude of the mutational effects varied depending on the target allele and the genetic background. Moreover, it was found that NILZS97 and NILMY46 carried different functional alleles of OsPUB3, causing differences in grain shape rather than grain weight. In the overexpression experiment, significant differences between transgenic-positive and transgenic-negative plants were detected in all four traits. These results indicate that OsPUB3 regulates grain shape and size through a complex mechanism and is a good target for deciphering the regulatory network of grain shape. This gene could be used to improve grain appearance quality through molecular breeding as well.

17.
BMC Med Imaging ; 22(1): 170, 2022 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-36175879

RESUMO

INTRODUCTION: Calcaneal fractures, especially those involving the articular surface, should be anatomically reduced as much as possible. Fixing the fracture by placing a screw into the sustentaculum tali from the lateral side of the calcaneus is generally considered to be the key to successful surgery. However, due to the limited visibility during surgery, it is not easy to place screws into the sustentaculum tali accurately. The purpose of this study was to explore a new fluoroscopy method for the sustentaculum tali and verify the value of this method in improving screw placement accuracy. METHODS: In this study, a total of 42 human foot and ankle specimens were dissected and measured. The shape and position of the sustentaculum tali were observed, and the influence of adjacent bones on imaging findings was analysed. The axial and frontal X-ray fluoroscopy method to view the sustentaculum tali was formulated, and the appropriate projection angle through anatomical and image measurements was explored. Thirty specimens were randomly selected for screw placement, and the direction of the screw was dynamically adjusted under the new imaging method. The success rate of sustentacular screw placement was evaluated. RESULTS: The anteversion angles of the sustentaculum tali were 30.81 ± 2.21° and 30.68 ± 2.86° by anatomical and imaging measurements, respectively. There was no statistically significant difference in the anteversion angle between the two measurement methods. Harris heel views should be obtained at 30° to identify the sustentaculum tali on axial X-ray images. Frontal X-ray imaging was performed perpendicular to this projection angle. Through frontal and axial X-ray imaging, the position and shape of the sustentaculum tali can be clearly observed, and these factors are seldom affected by adjacent bones. Under the new fluoroscopy method, the screws were placed from the anterior region of the lateral wall of the calcaneus to the sustentaculum tali. A total of 60 screws were placed in the 30 specimens; of these, 54 screws were in good position, 2 screws penetrated the cortical bone, and 4 screws did not enter the sustentaculum tali. The success rate of sustentacular screw placement was 90% (54/60). CONCLUSIONS: Axial and frontal X-ray images of the sustentaculum tali can clearly show the shape of the structure, which improves sustentacular screw placement accuracy.


Assuntos
Calcâneo , Fraturas Ósseas , Parafusos Ósseos , Calcâneo/cirurgia , Fluoroscopia , Fixação Interna de Fraturas , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Humanos , Raios X
18.
Chem Commun (Camb) ; 58(59): 8218-8221, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35790175

RESUMO

[Zn(3-tba)2], 1, a 1-D coordination polymer synthesised as 1 DMA, 1α, transformed to a nonporous form, 1ß, upon activation. 1ß underwent further transformation to the dimeric complex [Zn(3-tba)2(H2O)2], 2, above 40% RH. The reverse transformations, 2 to 1ß and 1ß to 1α, were accomplished by heating and exposure to DMA, respectively, and were single-crystal-to-single-crystal phase changes. Single crystal X-ray diffraction revealed that the second transformation resulted from Zn-carboxylate bond breakage and concomitant coordination of water molecules. Other solvent molecules did not induce a phase change.

19.
Int J Dev Biol ; 66(4-5-6): 305-309, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35770734

RESUMO

The aim of this study was to investigate the correlation between CDK1 protein and CDK1 mRNA during oocyte maturation in vivo in mouse. GV, GVBD, MI and MII oocytes were obtained from mice, respectively. Western blot validated that the CDK1 protein expression increased continuously and significantly with oocyte maturation in vivo (P<0.05). Real-time qRT-PCR showed that CDK1 mRNA expression was down-regulated significantly during transformation from GV to MI stages (P<0.05), and up-regulated significantly during transformation from MI to MII stages (P<0.05). The level of CDK1 mRNA peaked at MII stages. Spearman correlation analysis indicated that CDK1 protein expression was poor correlation with CDK1 mRNA expression during oocyte maturation in vivo (R=0.200). This finding suggested that the increase of CDK1 protein during oocyte maturation in vivo was not entirely caused by the change of transcription level. The results provide new food for thought for further research on the molecular mechanism of oocyte maturation in vivo.


Assuntos
Oócitos , Oogênese , Animais , Camundongos , Oócitos/metabolismo , Oogênese/genética , RNA Mensageiro/genética
20.
Sci Rep ; 12(1): 2707, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177730

RESUMO

Root zone microbial structure is particularly complex in plants with rhizosheaths, and greater understanding of the rhizosheath may play an important role in the future development of sustainable agricultural practices. However, one important reason to focus study on rhizosheath microbial structure is that there is no definite method for rhizosheath separation. The aim of this study was to explore rhizosheath isolation methods and the diversity characteristics of microorganisms around the rhizosphere. In this study, we isolated the rhizosheath of Stipa grandis, a dominant species in desert steppe, and the microorganisms in the roots, root epidermis, rhizosheath and rhizosphere soil were extracted and sequenced by 16S rRNA and ITS. The alpha diversity index of bacteria in Stipa grandis rhizosphere soil was the greatest, followed by rhizosheath, and the alpha diversity index of endophytic bacteria in root system was the smallest. The alpha diversity index of fungi in the rhizosheath and rhizosphere soil were significantly higher than that in the root epidermis and root system. There were significant differences in bacterial community structure between the root epidermis, endophytic bacteria, rhizosheath and rhizosphere soil. Unlike bacterial community structure, the community structure of fungi in the root epidermis was similar that of endophytic fungi, but significantly different from those in rhizosheath and rhizosphere soil. This study demonstrated a feasible method for separating plant rhizosheath and root epidermis. We suggest that the root epidermis can act as the interface between the host plant root and the external soil environment. We will have to re-examine the biological and ecological significance of rhizosheath and microorganisms in rhizosheath, as well as the mechanism explaining the close relationship of the rhizosheath and the plant root epidermis. This study provides theoretical and technical guidance for the isolation of the plant rhizosheath and the study of microorganisms in plant rhizosheath.


Assuntos
Microbiota/genética , Raízes de Plantas/microbiologia , Poaceae/microbiologia , Bactérias/genética , Fungos/genética , RNA Ribossômico 16S , Rizosfera , Solo , Microbiologia do Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...