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1.
J Plast Reconstr Aesthet Surg ; 93: 254-260, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38723511

RESUMEN

PURPOSE OF THE STUDY: To elucidate the design and fabrication methodologies employed in creating a personalized cleft lip simulation model, primarily intended for enhancing surgical training and diverse applications. The study further sought to assess the viability of integrating this simulation model into undergraduate oral experiments and instructional settings. STUDY DESIGN: Facial data from individuals with cleft lip conditions were acquired using a scanner. Subsequent stages involved reverse engineering and the utilization of 3D printing technology to generate a cleft lip silicone simulation model. The molding process entailed injecting silicone into a polylactic acid mold. The study enrolled 53 undergraduate students majoring in dentistry, who were randomly assigned to either a control or experimental group. A dedicated instructor guided each group independently, employing a combination of multiple-choice tests and surveys to gauge real-time evaluations and discern inter-group disparities. RESULTS AND CONCLUSIONS: We successfully designed and produced a personalized cleft lip simulation model, demonstrating notable efficacy in the context of cleft lip experimental teaching. Statistical analysis revealed a significant difference (P < 0.05) in the scores of the experimental group students on multiple-choice questions pertaining to cleft lip surgical procedures. Survey outcomes indicated that the experimental group students exhibited higher confidence levels in cleft lip surgery, as reflected from their responses to relevant questions, compared to the traditional group students. These differences were statistically significant (P < 0.05). The simulation model developed in this study emerges as a reliable and cost-effective training and teaching tool for cleft lip surgery.

2.
Environ Sci Technol ; 58(16): 6978-6987, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38598712

RESUMEN

Decarbonization of the cement sector is essentially required to achieve carbon neutrality to combat climate change. Amine-based CO2 capture is a leading and practical technology to deeply remove CO2 from the cement industry, owing to its high retrofittability to existing cement plants and extensive engineering experience in industrial flue gas decarbonization. While research efforts have been made to achieve low-carbon cement with 90% CO2 removal, a net-zero-emission cement plant that will be required for a carbon neutrality society has not yet been investigated. The present study proposed an advanced amine-based CO2 capture system integrated with a cement plant to achieve net-zero CO2 emission by pushing the CO2 capture efficiency to 99.7%. Monoethanomaine (MEA) and piperazine/2-amino-2-methyl-1-propanol (PZ-AMP) amine systems, which are considered to be the first- and second-generation capture agents, respectively, were detailed investigated to deeply decarbonize the cement plant. Compared to MEA, the advanced PZ-AMP system exhibited excellent energy performance with a regeneration duty of ∼2.6 GJ/tonne CO2 at 99.7% capture, 39% lower than the MEA process. This enabled a low CO2 avoided cost of $72.0/tonne CO2, which was 18% lower than that of the MEA-based zero-emission process and even 16.2% lower than the standard 90% MEA process. Sensitivity analysis revealed that the zero-emission capture cost of the PZ-AMP system would be further reduced to below $56/tonne CO2 at a $4/GJ steam production cost, indicating its economic competitiveness among various CO2 capture technologies to achieve a zero-emission cement plant.


Asunto(s)
Aminas , Dióxido de Carbono , Dióxido de Carbono/química , Aminas/química , Materiales de Construcción
4.
J Virus Erad ; 10(1): 100365, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38590730

RESUMEN

This study is a single-arm, single-center phase IV clinical trial on a rabies vaccine that has been marketed in China. The Vero cells and CTN-1V strain are used in the rabies vaccine product. The purpose of this study was to investigate the safety, immunogenicity and immune persistence of this product. One hundred and forty-nine participants were enrolled to the study, all of whom were included in the safety analysis set (SS), among which 116 participants were included in the protocol analysis set (PPS), One hundred and fifteen participants were included in the 6-month immune persistence analysis set (IPS6) and 111 in the 12-month immune persistence analysis set IPS12. Results showed that: 1) In the SS analysis set, adverse reactions were mainly pyrexia and pain at the vaccination site, the severity of which were mostly grade 1, and concentrated in 0-3 days after vaccination. No grade 3 or above adverse events and serious adverse events (SAE) related to the experimental vaccine were observed. 2) In the PPS analysis set, the antibody positive conversion rate reached 100% at 14 days after full immunization of the pre-immunized negative population; The antibody geometric mean titer (GMT) (95% CI) was 14.82 (13.00, 16.90). 3) The positive rate of serum neutralizing antibody was 93.91 % and the GMT at 1.58 IU/ml at 6 months after full immunization. The positive rate of neutralizing antibody was 85.59 % and GMT at 1.30 IU/ml at 12 months after immunization. Our results show that the human rabies vaccine with the CTN-1V strain and Vero cells as matrix had good safety, immunogenicity and immune persistence in our study.

5.
Small ; : e2400661, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38597688

RESUMEN

Renewable energy-driven conversion of CO2 to value-added fuels and chemicals via electrochemical CO2 reduction reaction (CO2RR) technology is regarded as a promising strategy with substantial environmental and economic benefits to achieve carbon neutrality. Because of its sluggish kinetics and complex reaction paths, developing robust catalytic materials with exceptional selectivity to the targeted products is one of the core issues, especially for extensively concerned Cu-based materials. Manipulating Cu species by anionic coordination is identified as an effective way to improve electrocatalytic performance, in terms of modulating active sites and regulating structural reconstruction. This review elaborates on recent discoveries and progress of Cu-based CO2RR catalytic materials enhanced by anionic coordination control, regarding reaction paths, functional mechanisms, and roles of different non-metallic anions in catalysis. Finally, the review concludes with some personal insights and provides challenges and perspectives on the utilization of this strategy to build desirable electrocatalysts.

6.
Mol Med ; 30(1): 46, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38584262

RESUMEN

Effective therapeutic targets and early diagnosis are major challenges in the treatment of gastrointestinal tract (GIT) cancers. SALL4 is a well-known transcription factor that is involved in organogenesis during embryonic development. Previous studies have revealed that SALL4 regulates cell proliferation, survival, and migration and maintains stem cell function in mature cells. Additionally, SALL4 overexpression is associated with tumorigenesis. Despite its characterization as a biomarker in various cancers, the role of SALL4 in GIT cancers and the underlying mechanisms are unclear. We describe the functions of SALL4 in GIT cancers and discuss its upstream/downstream genes and pathways associated with each cancer. We also consider the possibility of targeting these genes or pathways as potential therapeutic options for GIT cancers.


Asunto(s)
Neoplasias Gastrointestinales , Factores de Transcripción , Humanos , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Neoplasias Gastrointestinales/genética , Células Madre/metabolismo , Desarrollo Embrionario , Línea Celular Tumoral
7.
Microbiol Spectr ; 12(5): e0324523, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38602397

RESUMEN

Microorganisms are a crucial component of lake ecosystems and significant contributors to biogeochemical cycles. However, the understanding of how primary microorganism groups (e.g., bacteria and fungi) are distributed and constructed within different lake habitats is lacking. We investigated the bacterial and fungal communities of Hulun Lake using high-throughput sequencing techniques targeting 16S rRNA and Internal Transcribed Spacer 2 genes, including a range of ecological and statistical methodologies. Our findings reveal that environmental factors have high spatial and temporal variability. The composition and community structures vary significantly depending on differences in habitats. Variance partitioning analysis showed that environmental and geographical factors accounted for <20% of the community variation. Canonical correlation analysis showed that among the environmental factors, temperature, pH, and dissolved oxygen had strong control over microbial communities. However, the microbial communities (bacterial and fungal) were primarily controlled by the dispersal limitations of stochastic processes. This study offers fresh perspectives regarding the maintenance mechanism of bacterial and fungal biodiversity in lake ecosystems, especially regarding the responses of microbial communities under identical environmental stress.IMPORTANCELake ecosystems are an important part of the freshwater ecosystem. Lake microorganisms play an important role in material circulation and energy flow owing to their unique enzymatic and metabolic capacity. In this study, we observed that bacterial and fungal communities varied widely in the water and sediments of Hulun Lake. The primary factor affecting their formation was identified as dispersal limitation during stochastic processes. Environmental and geographical factors accounted for <20% of the variation in bacterial and fungal communities, with pH, temperature, and dissolved oxygen being important environmental factors. Our findings provide new insights into the responses of bacteria and fungi to the environment, shed light on the ecological processes of community building, and deepen our understanding of lake ecosystems. The results of this study provide a reference for lake management and conservation, particularly with respect to monitoring and understanding microbial communities in response to environmental changes.


Asunto(s)
Bacterias , Biodiversidad , Hongos , Lagos , Microbiota , Lagos/microbiología , Hongos/genética , Hongos/clasificación , Hongos/aislamiento & purificación , Bacterias/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , Microbiota/genética , Ecosistema , ARN Ribosómico 16S/genética , Procesos Estocásticos , Micobioma , Temperatura , Concentración de Iones de Hidrógeno , China
8.
Int J Biol Macromol ; 266(Pt 2): 131279, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38561115

RESUMEN

The influence of ferulic acid (FA) on rice starch was investigated by incorporating it at various concentrations (0, 2.5, 5, 7.5, and 10 %, w/w, on dry starch basis) and subjecting the resulting composites to hot-extrusion 3D printing (HE-3DP) process. This study examined the effects of FA addition and HE-3DP on the structural, rheological, and physicochemical properties as well as the printability and digestibility of rice starch. The results indicated that adding 0-5 % FA had no significant effect; however, as the amount of FA increased, the printed product edges became less defined, the product's overall stability decreased, and it collapsed. The addition of FA reduced the elasticity and viscosity, making it easier to extrude the composite gel from the nozzle. Moreover, the crystallinity and short-range ordered structure of the HE-3D printed rice starch gel decreased with the addition of FA, resulting in a decrease in the yield stress and an increase in fluidity. Furthermore, the addition of FA reduced the digestibility of the HE-3D-printed rice starch. The findings of this study may be useful for the development of healthier modified starch products by adding bioactive substances and employing the 3D printing technology.


Asunto(s)
Ácidos Cumáricos , Oryza , Impresión Tridimensional , Reología , Almidón , Almidón/química , Oryza/química , Ácidos Cumáricos/química , Viscosidad , Calor , Digestión/efectos de los fármacos
9.
Environ Sci Technol ; 58(10): 4606-4616, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38427797

RESUMEN

Transforming hazardous species into active sites by ingenious material design was a promising and positive strategy to improve catalytic reactions in industrial applications. To synergistically address the issue of sluggish CO2 desorption kinetics and SO2-poisoning solvent of amine scrubbing, we propose a novel method for preparing a high-performance core-shell C@Mn3O4 catalyst for heterogeneous sulfur migration and in situ reconstruction to active -SO3H groups, and thus inducing an enhanced proton-coupled electron transfer (PCET) effect for CO2 desorption. As anticipated, the rate of CO2 desorption increases significantly, by 255%, when SO2 is introduced. On a bench scale, dynamic CO2 capture experiments reveal that the catalytic regeneration heat duty of SO2-poisoned solvent experiences a 32% reduction compared to the blank case, while the durability of the catalyst is confirmed. Thus, the enhanced PCET of C@Mn3O4, facilitated by sulfur migration and simultaneous transformation, effectively improves the SO2 resistance and regeneration efficiency of amine solvents, providing a novel route for pursuing cost-effective CO2 capture with an amine solvent.


Asunto(s)
Dióxido de Carbono , Protones , Electrones , Solventes , Aminas , Azufre
10.
Environ Sci Technol ; 58(12): 5557-5566, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38412381

RESUMEN

Wet flue gas denitrification offers a new route to convert industrial nitrogen oxides (NOx) into highly concentrated nitrate wastewater, from which the nitrogen resource can be recovered to ammonia (NH3) via electrochemical nitrate reduction reactions (NITRRs). Low-cost, scalable, and efficient cathodic materials need to be developed to enhance the NH3 production rate. Here, in situ electrodeposition was adopted to fabricate a foamy Cu-based heterojunction electrode containing both Cu-defects and oxygen vacancy loaded Cu2O (OVs-Cu2O), which achieved an NH3 yield rate of 3.59 mmol h-1 cm-2, NH3 Faradaic efficiency of 99.5%, and NH3 selectivity of 100%. Characterizations and theoretical calculations unveiled that the Cu-defects and OVs-Cu2O heterojunction boosted the H* yield, suppressed the hydrogen evolution reaction (HER), and served as dual reaction sites to coherently match the tandem reactions kinetics of NO3-to-NO2 and NO2-to-NH3. An integrated system was further built to combine wet flue gas denitrification and desulfurization, simultaneously converting NO and SO2 to produce the (NH4)2SO4 fertilizer. This study offers new insights into the application of low-cost Cu-based cathode for electrochemically driven wet denitrification wastewater valorization.


Asunto(s)
Amoníaco , Aguas Residuales , Nitratos/química , Dióxido de Nitrógeno , Desnitrificación , Electrodos
11.
Environ Pollut ; 345: 123507, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38325508

RESUMEN

As a potential low-cost and environmentally friendly strategy, bioremediation of herbicide polluted soil has attracted increasing attention. However, there is a lack of knowledge regarding the response of the atrazine-degrading bacterial community to coinoculation of arbuscular mycorrhizal (AM) fungi and rhizobia for atrazine dissipation. In this study, a pot experiment was conducted with AM fungi Glomus mosseae (AM), rhizobia Rhizobium trifolii TA-1 (R) and their coinoculation (AMR) with atrazine. In each treatment, the atrazine-degrading bacterial community of four soil size aggregates, namely large macroaggregates (LMa), small macroaggregates (SMa), microaggregates (Mia) and primary particles (P) were investigated. The results showed that the atrazine residue concentration was lowest in AMR, and that in LMa was also significantly lower than that in the other smaller aggregate sizes. Overall, inoculation, the aggregate fraction and their interaction had significant effects on soil TN, SOC, AP and pH. For the atrazine-degrading bacterial community, the Chao1 index increased with decreasing particle size, but the Shannon index decreased. Moreover, the abundances of the dominant atrazine-degrading bacterial genera Arthrobacter, Bacillus, Marmoricola and Nocardioides in the Mia and P particle size groups were greater than those in the LMa and SMa groups in each treatment. The bacterial communities in the Mia and P particle sizes in each treatment group were more complex. Therefore, coinoculation of AM fungi and rhizobia stimulated atrazine dissipation by changing the atrazine-degrading bacterial community, and the response of the atrazine-degrading bacterial community to each aggregate size varied depending on its distinct soil physicochemical properties.


Asunto(s)
Atrazina , Micorrizas , Rhizobium , Contaminantes del Suelo , Atrazina/análisis , Micorrizas/fisiología , Suelo , Microbiología del Suelo , Hongos , Bacterias , Biodegradación Ambiental , Contaminantes del Suelo/análisis
12.
Int J Biol Macromol ; 262(Pt 2): 129949, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38311132

RESUMEN

Chikungunya virus (CHIKV) is a single positive-stranded RNA virus of the Togaviridae family and Alphavirus genus, with a typical lipid bilayer envelope structure, and is the causative agent of human chikungunya fever (CHIKF). The U.S. Food and Drug Administration has recently approved the first chikungunya vaccine, Ixchiq; however, vaccination rates are low, and CHIKF is prevalent owing to its periodic outbreaks. Thus, developing effective anti-CHIKV drugs in clinical settings is imperative. Viral proteins encoded by the CHIKV genome play vital roles in all stages of infection, and developing therapeutic agents that target these CHIKV proteins is an effective strategy to improve CHIKF treatment efficacy and reduce mortality rates. Therefore, in the present review article, we aimed to investigate the basic structure, function, and replication cycle of CHIKV and comprehensively outline the current status and future advancements in anti-CHIKV drug development, specifically targeting nonstructural (ns) proteins, including nsP1, nsP2, nsP3, and nsP4 and structural proteins such as capsid (C), E3, E2, 6K, and E1.


Asunto(s)
Fiebre Chikungunya , Virus Chikungunya , Humanos , Preparaciones Farmacéuticas , Replicación Viral/genética , Fiebre Chikungunya/tratamiento farmacológico , Fiebre Chikungunya/genética , Fiebre Chikungunya/metabolismo , Proteínas no Estructurales Virales/metabolismo
13.
Entropy (Basel) ; 26(1)2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38248173

RESUMEN

This paper introduces the notion of multi-sensitivity with respect to a vector within the context of non-autonomous dynamical systems on uniform spaces and provides insightful results regarding N-sensitivity and strongly multi-sensitivity, along with their behaviors under various conditions. The main results established are as follows: (1) For a k-periodic nonautonomous dynamical system on a Hausdorff uniform space (S,U), the system (S,fk∘⋯∘f1) exhibits N-sensitivity (or strongly multi-sensitivity) if and only if the system (S,f1,∞) displays N-sensitivity (or strongly multi-sensitivity). (2) Consider a finitely generated family of surjective maps on uniform space (S,U). If the system (S,f1,∞) is N-sensitive, then the system (S,fk,∞) is also N-sensitive. When the family f1,∞ is feebly open, the converse statement holds true as well. (3) Within a finitely generated family on uniform space (S,U), N-sensitivity (and strongly multi-sensitivity) persists under iteration. (4) We present a sufficient condition under which an nonautonomous dynamical system on infinite Hausdorff uniform space demonstrates N-sensitivity.

14.
Diabetes Metab Syndr Obes ; 17: 215-225, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38229907

RESUMEN

Introduction: To investigate the predictors of diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM) patients and establish a nomogram model for predicting the risk of DKD. Methods: The clinical data of T2DM patients, admitted to the Endocrinology Department of Chengde Central Hospital from October 2019 to September 2020 and divided into a case group or a control group based on whether they had DKD, were collected. The predictive factors of DKD were screened by univariate and multivariate analysis, and a nomogram prediction model was constructed for the risk of DKD in T2DM. Bootstrapping was used for model validation, receiver operating characteristic (ROC) curve and GiViTI calibration curve were used for evaluating the discrimination and calibration of prediction model, and decision analysis curve (DCA) was used for evaluating the practicality of model. Results: Predictors for DKD are diabetic retinopathy (DR), hypertension, history of gout, smoking history, using insulin, elevation of body mass index (BMI), triglyceride (TG), cystatin C (Cys-C), and reduction of 25 (OH) D. The nomogram prediction model based on the above nine predictors had good representativeness (Bootstrap method: precision: 0.866, Kappa: 0.334), differentiation [the area under curve (AUC) value: 0.868], and accuracy (GiViTI-corrected curved bands, P = 0.836); the DAC curve analysis showed that the prediction model, whose threshold probability was in the range of 0.10 to 0.70, had clinical practical value. Conclusion: The risk of DKD in T2DM could be predicted accurately by DR, hypertension, history of gout, smoking history, using insulin, elevation of BMI, TG, Cys-C, and reduction of 25 (OH) D.

15.
Oncogene ; 43(7): 495-510, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38168654

RESUMEN

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies in the world with poor prognosis. Despite the promising applications of immunotherapy, the objective response rate is still unsatisfactory. We have previously shown that Hippo/YAP signaling acts as a powerful tumor promoter in ESCC. However, whether Hippo/YAP signaling is involved in tumor immune escape in ESCC remains largely unknown. Here, we show that YAP directly activates transcription of the "don't eat me" signal CD24, and plays a crucial role in driving tumor cells to avoid phagocytosis by macrophages. Mechanistically, YAP regulates CD24 expression by interacting with TEAD and binding the CD24 promoter to initiate transcription, which facilitates tumor cell escape from macrophage-mediated immune attack. Our animal model data and clinical data show that YAP combined with CD24 in tumor microenvironment redefines the impact of TAMs on the prognosis of ESCC patients which will provide a valuable basis for precision medicine. Moreover, treatment with YAP inhibitor altered the distribution of macrophages and suppressed tumorigenesis and progression of ESCC in vivo. Together, our study provides a novel link between Hippo/YAP signaling and macrophage-mediated immune escape, which suggests that the Hippo-YAP-CD24 axis may act as a promising target to improve the prognosis of ESCC patients. A proposed model for the regulatory mechanism of Hippo-YAP-CD24-signaling axis in the tumor-associated macrophages mediated immune escape.


Asunto(s)
Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Animales , Humanos , Transducción de Señal/fisiología , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias Esofágicas/genética , Evasión Inmune , Proteínas Señalizadoras YAP , Macrófagos/metabolismo , Fagocitosis , Línea Celular Tumoral , Microambiente Tumoral , Antígeno CD24
16.
Br J Educ Psychol ; 94(1): 181-197, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37963575

RESUMEN

BACKGROUND: Mathematics homework is highly prevalent in East Asia. Teachers and parents expect mathematics homework to improve students' performance; however, studies have not clearly defined the effectiveness of the assignment of different amounts of homework. AIMS: This study analyses the differential effect of homework amount on various facets of Chinese students' mathematics achievement using a longitudinal design. It aims, thereby, to contribute to the existing knowledge of homework effectiveness and mathematics learning and to provide insights for student development. SAMPLE: The sample included 2383 grade 9 students from a mid-sized city with a moderate level of economic and educational development in central China. METHODS: We administered a student-reported questionnaire, collected school reports of mathematics achievements to track retrospective longitudinal variations in mathematics over half a year and analysed the differential effectiveness of homework on mathematics achievement at four hierarchical cognitive levels with Hierarchical Linear Model. RESULTS: The results indicated that assigning more homework at the class level could enhance students' mathematics achievement at a low cognitive level, although this effectiveness tended to disappear when the set homework time reached about 1.5-2 h. We did not find evidence that assigning more homework enhances students' mathematics achievement at higher cognitive levels. CONCLUSIONS: Overall, this study provides evidence on the effectiveness of homework and offers implications for educational practice and future research.


Asunto(s)
Estudiantes , Humanos , China , Estudios Longitudinales , Matemática , Estudios Retrospectivos , Estudiantes/psicología , Logro
17.
Environ Sci Technol ; 57(45): 17553-17565, 2023 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-37917662

RESUMEN

The hydrogenation of organic sulfur (CS2) present in industrial off-gases to produce sulfur-free hydrocarbons and H2S can be achieved by using noble-metal catalysts. However, there has been a lack of comprehensive investigation into the underlying reaction mechanisms associated with this process. In this study, we have conducted an in-depth examination of the activity and selectivity of Pt- and Pd-loaded alumina-based catalysts, revealing significant disparities between them. Notably, Pd/Al2O3 catalysts exhibit an enhanced performance at low temperatures. Furthermore, we have observed that CS2 displays a higher propensity for conversion to methane when employing Pt/Al2O3 catalysts, while Pd/Al2O3 catalysts demonstrate a greater tendency for coke deposition. By combining experimental observations with theoretical calculations, we revealed that the capability of H2 spillover along with the adsorption capacity of CS2, play pivotal roles in determining the observed differences. Moreover, the key intermediate species involved in the methanation and coke pathways were identified. The intermediate CH2S* is found to be crucial in the methanation pathway, while the intermediate CSH* is identified as significant in the coke pathway.


Asunto(s)
Coque , Adsorción , Óxido de Aluminio , Hidrogenación , Azufre
18.
Front Plant Sci ; 14: 1240675, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37920713

RESUMEN

Background: The bacterial communities of the root surface and rhizosphere play a crucial role in the decomposition and transformation of soil nitrogen (N) and are also affected by soil N levels and distribution, especially the composition and diversity, which are sensitive to changes in the environment with high spatial and temporal heterogeneity of ammonium N (NH4 +-N) and nitrate N (NO3 --N). Methods: One-year-old seedlings of Cunninghamia lanceolata and Schima superba were subjected to N stress (0.5 mmol L-1) and normal N supply (2 mmol L-1), and five different N form ratios (NH4 +-N to NO3 --N ratio of 10:0, 0:10, 8:2, 2:8, and 5:5) were created. We analyze the changes in composition and diversity of bacteria in the root surface and rhizosphere of two tree species by high-throughput sequencing. Results: Differences in the composition of the major bacteria in the root surface and rhizosphere of C.lanceolata and S. superba under N stress and N form ratios were not significant. The dominant bacterial phyla shared by two tree species included Proteobacteria and Bacteroidota. Compared to normal N supply, the patterns of diversity in the root surface and rhizosphere of two tree species under N stress were distinct for each at five N form ratios. Under N stress, the bacterial diversity in the root surface was highest at NH4 +-N to NO3 --N ratio of 10:0 of C. lanceolata, whereas in the root surface, it was highest at the NH4 +-N to NO3 --N ratio of 0:10 of S. superba. The NH4 +-N to NO3 --N ratio of 5:5 reduced the bacterial diversity in the rhizosphere of two tree species, and the stability of the bacterial community in the rhizosphere was decreased in C. lanceolata. In addition, the bacterial diversity in the root surface was higher than in the rhizosphere under the N stress of two tree species. Conclusion: The bacterial compositions were relatively conserved, but abundance and diversity changed in the root surface and rhizosphere of C. lanceolata and S. superba under N stress and different N form ratios. The heterogeneity of ammonium and nitrate N addition should be considered for N-stressed environments to improve bacterial diversity in the rhizosphere of two tree species.

19.
Environ Sci Technol ; 57(41): 15465-15474, 2023 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-37782821

RESUMEN

Metal-molecular sieve composites with high acidity are promising solid acid catalysts (SACs) for accelerating sluggish CO2 desorption processes and reducing the energy consumption of CO2 chemisorption systems. However, the production of such SACs through conventional approaches such as loading or ion-exchange methods often leads to uncontrolled and unstable metal distribution on the catalysts, which limits their pore structure regulation and catalytic performance. In this study, we demonstrated a feasible strategy for improving the durability, surface chemical activity, and pore structure of metal-doped HZSM-5 through bimetallic Mo/Mn modification. This strategy involves the immobilization of Mo-O-Mn species confined in an MFI structure by regulating MoO42- anions and Mn2+ cations. The embedded Mn/Mo species of low valence can strongly induce electron transfer and increase the density of compensatory H+ on the MoMn@H catalyst, thereby reducing the CO2 desorption temperature by 8.27 °C and energy consumption by 37% in comparison to a blank. The durability enhancement and activity regulation method used in this study is expected to advance the rational synthesis of metal-molecular sieve composites for energy-efficient CO2 capture using amine regeneration technology.


Asunto(s)
Aminas , Dióxido de Carbono , Catálisis , Transporte de Electrón , Intercambio Iónico
20.
mBio ; : e0227623, 2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37855599

RESUMEN

Plasmid conjugation plays an important role in the dissemination of antibiotic-resistance genes. The emergence of multidrug-resistant isolates of Acinetobacter baumannii poses grave challenges in treating infections caused by this notorious nosocomial pathogen. Yet, the composition, functionality, and regulation of conjugative machinery utilized by A. baumannii remain poorly understood. Here, we found that conjugation of the major plasmid pAB3 of A. baumannii is mediated by a type IVB secretion system similar to the Dot/Icm transporter of Legionella pneumophila. Furthermore, the expression of the structural genes of the Dot/Icm-like system is co-regulated with genes involved in central metabolism by the GacS/GacA two-component system in response to various metabolites, including intermediates of the tricarboxylic acid cycle. Loss of GacS/A also severely impaired bacterial virulence. These results establish that A. baumannii coordinates metabolism with plasmid conjugation and virulence by sensing nutrient availability, which may be exploited to develop inhibitory agents for controlling the spread of drug-resistance genes and virulence factors. IMPORTANCE Plasmid conjugation is known to be an energy-expensive process, but our understanding of the molecular linkage between conjugation and metabolism is limited. Our finding reveals that Acinetobacter baumannii utilizes a two-component system to co-regulate metabolism, plasmid transfer, and virulence by sensing reaction intermediates of key metabolic pathways, which suggests that nutrient availability dictates not only bacterial proliferation but also horizontal gene transfer. The identification of Dot/Icm-like proteins as components of a conjugation system involved in the dissemination of antibiotic-resistance genes by A. baumannii has provided important targets for the development of agents capable of inhibiting virulence and the spread of anti-microbial-resistance genes in bacterial communities.

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