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1.
3D Print Addit Manuf ; 11(2): e851-e859, 2024 Apr 01.
Article En | MEDLINE | ID: mdl-38689926

AlSi10Mg is widely used in additively manufacturing aeronautical lattice and honeycomb structures. The unclear complex quality characteristics has been an obstacle of nondestructive testing of additive manufacturing (AM) AlSi10Mg, especially at its as-built state. This article attempts to reveal the quality characteristics of as-built AM aeronautical AlSi10Mg based on its conductivity characteristics. Experimental results show that the quality of manufacturing is nonuniform. The nonuniformity of each sample surface is systematically evaluated. Along the building direction, the quality is best in the initial few layers and decreases as the built height increases. On this basis, a reference curve is obtained and used to describe the quality characteristics of as-built AM component along the building direction. Based on the quality characteristics, the inspection of small offsets caused by accidental failures during the manufacturing process is carried out. The offsets not <37 µm are detected with the help of the reference curve, whereas they are not discovered by the radiography testing. It proves that the proposed method of offset inspection is highly sensitive.

2.
Int J Biol Macromol ; 266(Pt 2): 131254, 2024 May.
Article En | MEDLINE | ID: mdl-38565362

Acorus tatarinowii, a famous traditional Chinese medicine, is used for the clinical treatment of memory impairment and dementia. In this research, AT50, the crude polysaccharide extracted from A. tatarinowii rhizome, significantly improved the memory and learning ability of mice with Alzheimer's disease (AD) and exerted excellent anti-neuroinflammatory effects. More importantly, AT50 returned the levels of NO, TNF-α, IL-1ß, PGE-2, and IL-6 in AD mouse brains to normal levels. To identify the active ingredients in AT50, a heteropolysaccharide ATP50-3 was obtained from AT50. Structural analysis indicated ATP50-3 consisted of α-L-Araf-(1→, →2)-α-L-Araf-(1→, →3)-α-L-Araf-(1→, →5)-α-L-Araf-(1→, α-D-Xylp-(1→, →3,4)-ß-D-Xylp-(1→, →3)-α-D-Galp-(1→, →3,6)-α-D-Galp-(1→, →6)-4-OAc-α-D-Galp-(1→, →3,4,6)-α-D-Galp-(1→, →4)-α-D-Glcp-(1→, →2,3,6)-ß-D-Glcp-(1→, →4,6)-α-D-Manp-(1→, →3,4)-α-L-Rhap-(1→, →4)-α-D-GalpA-(1→, and →4)-α-D-GlcpA-(1 â†’ residues and terminated with Xyl and Ara. Additionally, ATP50-3 significantly inhibited the release of proinflammatory factors in lipopolysaccharide-stimulated BV2 cells. ATP50-3 may be an active constituent of AT50, responsible for its anti-neuroinflammatory effects, with great potential to treat AD.


Acorus , Anti-Inflammatory Agents , Polysaccharides , Rhizome , Acorus/chemistry , Animals , Rhizome/chemistry , Mice , Polysaccharides/pharmacology , Polysaccharides/chemistry , Polysaccharides/isolation & purification , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/chemistry , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Male , Neuroinflammatory Diseases/drug therapy , Disease Models, Animal
3.
Ann Hematol ; 2024 Apr 17.
Article En | MEDLINE | ID: mdl-38630131

Antiplatelet drugs in patients increase the risk of intracranial hemorrhage (ICH), which can seriously affect patients' quality of life and even endanger their lives. Currently, there is no specific score for predicting the risk of ICH caused by antiplatelet drugs. We aimed to identify factors associated with ICH in patients on antiplatelet drugs and to construct and validate a predictive model that would provide a validated tool for the clinic. Data were obtained from the patient medical records inpatient system. Prediction models were built by logistic regression, the area under the curve (AUC), and column line plots. Internal validation, analytical identification and calibration of the model using AUC, calibration curves and Hosmer-Lemeshow test. The registration number of this study is ChiCTR2000031909, and the ethical review number is 2020KY087. This single-center retrospective study enrolled 753 patients treated with antiplatelet drugs, including 527 in the development cohort. Multifactorial analysis showed that male, headache or vomiting, hypertension, cerebrovascular disease, CT-defined white matter hypodensity, abnormal GCS, fibrinogen and D-dimer were independent risk factors for ICH, and lipid-lowering drugs was a protective factor. The model was constructed using these nine factors with an AUC value of 0.949. In the validation cohort, the model showed good discriminatory power with an AUC value of 0.943 and good calibration (Hosmer-Lemeshow test P value of 0.818). Based on 9 factors, we derived and validated a predictive model for ICH with antiplatelet drugs in patients. The model has good predictive value and may be an effective tool to reduce the occurrence of ICH.

4.
Mater Horiz ; 11(8): 1867-1876, 2024 Apr 22.
Article En | MEDLINE | ID: mdl-38454889

Flame retardants are effective in protecting materials from fire but pose environmental challenges due to limited recyclability. Urgently needed for circular material economy are new flame retardants that are chemically recyclable and durable. Here, we report a new facile and scalable strategy for engineering reversible microcages with infinite chemical recyclability to starting monomers, exceptional durability, and versatile flame retardancy. This is achieved through a highly synergistic hierarchical assembly of easily obtainable phosphoric acid and Cu2+ monomers. By leveraging dynamic reversible assembly networks, microcages can be circularly and infinitely dissociated into starting monomers via eco-friendly pH adjustment. Remarkable recovery rates of 92% for phosphoric acid and 96.2% for Cu2+ monomers are achieved, while the separated virgin matrix undergoes conventional chemical recycling, facilitating reformulation and seamless reintroduction into new supply chains as needed. Notably, when integrated with matrix-like surfaces, microcage clasp matrices tightly engage through in situ formed interfacial locking structures, showcasing outstanding flame-retardant efficiency, prolonged durability in hydrothermal aging, and extensive applicability across diverse polymeric materials such as polyurethane, epoxy resin, and polycarbonate. This study emphasizes a novel, straightforward, and scalable chemical platform, utilizing reversible interfacial locking engineering, for the development of flame retardants that are not only infinitely recyclable but also durable and broadly applicable.

5.
Sci Rep ; 14(1): 5307, 2024 03 04.
Article En | MEDLINE | ID: mdl-38438438

This study introduces PDMotion, a mobile application comprising 11 digital tests, including those adapted from the MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III and novel assessments, for remote Parkinson's Disease (PD) motor symptoms evaluation. Employing machine learning techniques on data from 50 PD patients and 29 healthy controls, PDMotion achieves accuracies of 0.878 for PD status prediction and 0.715 for severity assessment. A post-hoc explanation model is employed to assess the importance of features and tasks in diagnosis and severity evaluation. Notably, novel tasks that are not adapted from MDS-UPDRS Part III like the circle drawing, coordination test, and alternative tapping test are found to be highly important, suggesting digital assessments for PD can go beyond digitizing existing tests. The alternative tapping test emerges as the most significant task. Using its features alone achieves prediction accuracies comparable to the full task set, underscoring its potential as an independent screening tool. This study addresses a notable research gap by digitalizing a wide array of tests, including novel ones, and conducting a comparative analysis of their feature and task importance. These insights provide guidance for task selection and future development in PD mobile assessments, a field previously lacking such comparative studies.


Mobile Applications , Parkinson Disease , Humans , Parkinson Disease/diagnosis , Machine Learning , Mental Status and Dementia Tests , Paracentesis
6.
ACS Appl Mater Interfaces ; 16(8): 10389-10397, 2024 Feb 28.
Article En | MEDLINE | ID: mdl-38364294

Perovskite nanocrystals have absorbed increasing interest, especially in the field of optoelectronics, owing to their unique characteristics, including their tunable luminescence range, robust solution processability, facile synthesis, and so on. However, in practice, due to the inherent instability of the traditional long-chain insulating ligands surrounding perovskite quantum dots (PeQDs), the performance of the as-fabricated QLED is relatively disappointing. Herein, the zwitterion 3-(decyldimethylammonio)propanesulfonate (DLPS) with the capability of double passivating perovskite quantum dots could effectively replace the original long-chain ligand simply through a multistep post-treatment strategy to finally inhibit the formation of defects. It was indicated from theexperimental results that the DLPS, as one type of ligand with the bimolecular ion, was very adavntageous in replacing long-chain ligands and further suppressing the formation of defects. Finally, the perovskite quantum dots with greatly enhanced PLQY as high as 98% were effectively achieved. Additionally, the colloidal stability of the corresponding PeQDs has been significantly enhanced, and a transparent colloidal solution was obtained after 45 days under ambient conditions. Finally, the as-fabricated QLEDs based on the ligand-exchanged PeQDs exhibited a maximum brightness of 9464 cd/m2 and an EQE of 12.17%.

7.
Korean J Intern Med ; 39(1): 77-85, 2024 Jan.
Article En | MEDLINE | ID: mdl-38062723

BACKGROUND/AIMS: There may be many predictors of anticoagulation-related gastrointestinal bleeding (GIB), but until now, systematic reviews and assessments of the certainty of the evidence have not been published. We conducted a systematic review to identify all risk factors for anticoagulant-associated GIB to inform risk prediction in the management of anticoagulation- related GIB. METHODS: A systematic review and meta-analysis were conducted to search PubMed, EMBASE, Web of Science, and Cochrane Library databases (from inception through January 21, 2022) using the following search terms: anticoagulants, heparin, warfarin, dabigatran, rivaroxaban, apixaban, DOACs, gastrointestinal hemorrhage, risk factors. According to inclusion and exclusion criteria, studies of risk factors for anticoagulation-related GIB were identified. Risk factors for anticoagulant-associated GIB were used as the outcome index of this review. RESULTS: We included 34 studies in our analysis. For anticoagulant-associated GIB, moderate-certainty evidence showed a probable association with older age, kidney disease, concomitant use of aspirin, concomitant use of the antiplatelet agent, heart failure, myocardial infarction, hematochezia, renal failure, coronary artery disease, helicobacter pylori infection, social risk factors, alcohol use, smoking, anemia, history of sleep apnea, chronic obstructive pulmonary disease, international normalized ratio (INR), obesity et al. Some of these factors are not included in current GIB risk prediction models. such as anemia, co-administration of gemfibrozil, co-administration of verapamil or diltiazem, INR, heart failure, myocardial infarction, etc. CONCLUSION: The study found that anemia, co-administration of gemfibrozil, co-administration of verapamil or diltiazem, INR, heart failure, myocardial infarction et al. were associated with anticoagulation-related GIB, and these factors were not in the existing prediction models. This study informs risk prediction for anticoagulant-associated GIB, it also informs guidelines for GIB prevention and future research.


Anticoagulants , Gastrointestinal Hemorrhage , Humans , Anemia , Anticoagulants/adverse effects , Diltiazem , Gastrointestinal Hemorrhage/chemically induced , Gemfibrozil , Heart Failure , Helicobacter Infections , Helicobacter pylori , Myocardial Infarction , Risk Factors , Verapamil
8.
Small ; 20(4): e2305462, 2024 Jan.
Article En | MEDLINE | ID: mdl-37715105

Substituting the low-value oxygen evolution reaction (OER) with thermodynamically more favored organic oxidation such as furfural oxidation reaction (FOR) is regarded as a perspective approach to decrease energy cost of hydrogen evolution from water splitting. However, the kinetic of FOR can be even more sluggish than OER under large current density. In this work, a strategy is proposed to accelerate FOR by enhancing the adsorption of oxygenates on active sites. Over the prepared NiMoP/NF anode, only 1.46 V versus RHE is required in furfural solution to achieve 500 mA cm-2 , significantly better than the OER activity over commercial RuO2 /NF under the same current density (1.57 V vs RHE).

9.
ACS Omega ; 8(43): 40417-40432, 2023 Oct 31.
Article En | MEDLINE | ID: mdl-37929143

Coal body desorption characteristics are one of the key factors that influence the development of coalbed methane (CBM). In this study, 91 coal core samples from 11 CBM wells in the Fukang mining area were collected from Xinjiang, China, and the coal quality, high-pressure mercury compression, gas content, and natural desorption characteristics measurements were launched. With the detailed analyses of the differences in cumulative desorption volume, desorption ratio, and on-site average desorption rate for the coal samples with different body structures and macrolithotypes, the influence of the maximum reflectance of vitrinite, microscopic coal rock composition, and coal quality and pore characteristics on CBM desorption characteristics were discussed. The results showed that the cumulative desorption volume, desorption ratio, and desorption rate of cataclastic structure-bright coal are higher than those of primary structure-semibright coal. With the increase of RO,max and vitrinite content, the adsorption capacity of coal increases, and the increased methane concentration difference during desorption leads to an increase in cumulative desorption volume and on-site average desorption rate. The higher contents of moisture and ash yield would occupy the adsorption sites and hinder gas diffusion, which would decrease the desorption of coalbed methane. The greater porosity/pore volume ratio of medium and large pores can enhance the connectivity of pores, which increases the desorption ratio and the average desorption rate, while the higher micropore porosity/pore volume ratio can increase the gas adsorption space and the cumulative desorption volume. The pore characteristics have the most significant effect on the cumulative desorption volume and desorption ratio. The results of the study can help guide coal mine gas management and CBM development from middle-and low-rank coal reservoirs in Xinjiang.

10.
Front Plant Sci ; 14: 1213486, 2023.
Article En | MEDLINE | ID: mdl-37900751

Measurements of rice physical traits, such as length, width, and percentage of filled/unfilled grains, are essential steps of rice breeding. A new approach for measuring the physical traits of rice grains for breeding purposes was presented in this study, utilizing image processing techniques. Backlight photography was used to capture a grayscale image of a group of rice grains, which was then analyzed using a clustering algorithm to differentiate between filled and unfilled grains based on their grayscale values. The impact of backlight intensity on the accuracy of the method was also investigated. The results show that the proposed method has excellent accuracy and high efficiency. The mean absolute percentage error of the method was 0.24% and 1.36% in calculating the total number of grain particles and distinguishing the number of filled grains, respectively. The grain size was also measured with a little margin of error. The mean absolute percentage error of grain length measurement was 1.11%, while the measurement error of grain width was 4.03%. The method was found to be highly accurate, non-destructive, and cost-effective when compared to conventional methods, making it a promising approach for characterizing physical traits for crop breeding.

11.
Microbiol Spectr ; 11(6): e0178423, 2023 Dec 12.
Article En | MEDLINE | ID: mdl-37819128

IMPORTANCE: Diseases caused by Enterobacteriaceae multidrug-resistant strains have become increasingly difficult to manage. It is necessary to verify the new antibacterial drug MccY effect on non-typhoid Salmonella infection in mice since it is regarded as a promising microcin. The results demonstrated that MccY has a potential therapeutic application value in the protection against Salmonella-induced intestinal damage and alleviating related intestinal dysbiosis and metabolic disorders. MccY could be a promising candidate as an antimicrobial or anti-inflammatory agent for treating infectious diseases.


Gastrointestinal Microbiome , Mice , Animals , Intestinal Barrier Function , Inflammation/drug therapy , Salmonella , Peptides , Dysbiosis/microbiology
12.
Environ Sci Pollut Res Int ; 30(46): 102104-102128, 2023 Oct.
Article En | MEDLINE | ID: mdl-37684506

Natural uranium is a crucial resource for clean nuclear energy, which has brought significant economic and social benefits to humanity. However, the development and utilization of uranium resources have also resulted in the accumulation of vast amounts of uranium mill tailings (UMTs), which pose a potential threat to human health and the ecological environment. This paper reviews the research progress on UMTs treatment technologies, including cover disposal, solidification disposal, backfilling disposal, and bioremediation methods. It is found that cover disposal is a versatile method for the long-term management of UMTs, the engineering performance and durability of the cover system can be improved by choosing suitable stabilizers for the cover layer. Solidification disposal can convert UMTs into solid waste for permanent disposal, but it produces a large amount of waste and requires high operating costs; it is necessary to explore the effectiveness and efficiency of solidification disposal for UMTs, while minimizing the bad environmental impact. Backfilling disposal realizes the resource utilization of solid waste, but the high radon exhalation rate caused by the UMTs backfilling also needs to be considered. Bioremediation methods have low investment costs and are less likely to cause secondary pollution, but the remediation efficiency is low, it can be combined with other treatment technologies to remedy the defects of a single remediation method. The article concludes with key issues and corresponding suggestions for the current UMTs treatment methods, which can provide theoretical guidance and reference for further development and application of radioactive pollution treatment of UMTs.

13.
Arterioscler Thromb Vasc Biol ; 43(11): 2143-2164, 2023 11.
Article En | MEDLINE | ID: mdl-37706320

BACKGROUND: Perivascular adipose tissue (PVAT) is vital for vascular homeostasis, and PVAT dysfunction is associated with increased atherosclerotic plaque burden. But the mechanisms underlining coronary PVAT dysfunction in coronary atherosclerosis remain elusive. METHODS: We performed single-cell RNA sequencing of the stromal vascular fraction of coronary PVAT from 3 groups of heart transplant recipients with end-stage heart failure, including 3 patients with nonobstructive coronary atherosclerosis, 3 patients with obstructive coronary artery atherosclerosis, and 4 nonatherosclerosis control subjects. Bioinformatics was used to annotate the cellular populations, depict the cellular developmental trajectories and interactions, and explore the differences among 3 groups of coronary PVAT at the cellular and molecular levels. Pathological staining, quantitative real-time polymerase chain reaction, and in vitro studies were performed to validate the key findings. RESULTS: Ten cell types were identified among 67 936 cells from human coronary PVAT. Several cellular subpopulations, including SPP1+ (secreted phosphoprotein 1) macrophages and profibrotic fibroadipogenic progenitor cells, were accumulated in PVAT surrounding atherosclerotic coronary arteries compared with nonatherosclerosis coronary arteries. The fibrosis percentage was increased in PVAT surrounding atherosclerotic coronary arteries, and it was positively associated with the grade of coronary artery stenosis. Cellular interaction analysis suggested OPN (osteopontin) secreted by SPP1+ macrophages interacted with CD44 (cluster of differentiation 44)/integrin on fibroadipogenic progenitor cells. Strikingly, correlation analyses uncovered that higher level of SPP1 in PVAT correlates with a more severe fibrosis degree and a higher coronary stenosis grade. In vitro studies showed that conditioned medium from atherosclerotic coronary PVAT promoted the migration and proliferation of fibroadipogenic progenitor cells, while such effect was prevented by blocking CD44 or integrin. CONCLUSIONS: SPP1+ macrophages accumulated in the PVAT surrounding atherosclerotic coronary arteries, and they promoted the migration and proliferation of fibroadipogenic progenitor cells via OPN-CD44/integrin interaction and thus aggravated the fibrosis of coronary PVAT, which was positively correlated to the coronary stenosis burden. Therefore, SPP1+ macrophages in coronary PVAT may participate in the progression of coronary atherosclerosis.


Atherosclerosis , Coronary Artery Disease , Coronary Stenosis , Heart Failure , Humans , Coronary Artery Disease/pathology , Osteopontin/genetics , Osteopontin/metabolism , Adipose Tissue/metabolism , Atherosclerosis/pathology , Coronary Stenosis/pathology , Macrophages/metabolism , Fibrosis , Integrins/metabolism , Sequence Analysis, RNA , Heart Failure/metabolism
14.
Bioresour Technol ; 384: 129269, 2023 Sep.
Article En | MEDLINE | ID: mdl-37290706

This study investigated the response of nitrite accumulation to elevated COD/NO3--N ratio (C/N) during partial denitrification (PD). Results indicated nitrite was gradually accumulated and remained stable (C/N = 1.5 âˆ¼ 3.0), while that rapidly declined after reaching the peak (C/N = 4.0 âˆ¼ 5.0). The polysaccharide (PS) and protein (PN) content of tightly-bound extracellular polymeric substances (TB-EPS) reached the maximum at C/N of 2.5 âˆ¼ 3.0, which might be stimulated by high level of nitrite. Illumina MiSeq sequencing showed Thauera and OLB8 were dominated denitrifying genera at C/N of 1.5 âˆ¼ 3.0, while Thauera was further enriched with fading OLB8 at C/N of 4.0 âˆ¼ 5.0. Meanwhile, the highly-enriched Thauera might enhance the activity of nitrite reductase (nirK) promoting further nitrite reduction. Redundancy analysis (RDA) showed positive correlations between nitrite production and PN content of TB-EPS, denitrifying bacteria (Thauera and OLB8) and nitrate reductases (narG/H/I) in low C/N. Finally, their synergistic effects for driving nitrite accumulation were comprehensively elucidated.


Microbiota , Nitrites , Nitrites/metabolism , Extracellular Polymeric Substance Matrix/metabolism , Denitrification , Nitrogen/metabolism , Thauera/metabolism
16.
Front Mol Biosci ; 10: 1128739, 2023.
Article En | MEDLINE | ID: mdl-37051325

Klinefelter syndrome (KS, 47XXY) is a disorder characterized by sex chromosomal aneuploidy, which may lead to changes in epigenetic regulations of gene expression. To define epigenetic architectures in 47XXY, we annotated DNA methylation in euploid males (46XY) and females (46XX), and 47XXY individuals using whole genome bisulfite sequencing (WGBS) and integrated chromatin accessbilty, and detected abnormal hypermethylation in 47XXY. Furthermore, we detected altered chromatin accessibility in 47XXY, in particular in chromosome X, using Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) in cultured amniotic cells. Our results construct the whole genome-wide DNA methylation map in 47XXY, and provide new insights into the early epigenomic dysregulation resulting from an extra chromosome X in 47XXY.

17.
Thromb J ; 21(1): 27, 2023 Mar 14.
Article En | MEDLINE | ID: mdl-36918881

BACKGROUND: Thrombolysis-related intracranial hemorrhage has a high mortality rate, and many factors can cause intracranial hemorrhage. Until now, systematic reviews and assessments of the certainty of the evidence have not been updated. AIM: We conducted a systematic review to identify risk factors for thrombolysis-related intracranial hemorrhage. METHOD: The protocol for this systematic review was prospectively registered with PROSPERO (CRD42022316160). All English studies that met the inclusion criteria published before January 2022 were obtained from PubMed, EMBASE, Web of Science, and Cochrane Library. Two researchers independently screened articles, extracted data, and evaluated the quality and evidence of the included studies. Risk factors for intracranial hemorrhage were used as the outcome index of this review. Random or fixed-effect models were used in statistical methods. RESULTS: Of 6083 citations, we included 105 studies in our analysis. For intracranial hemorrhage, moderate-certainty evidence showed a probable association with age, National Institutes of Health stroke scale, leukoaraiosis, hypertension, atrial fibrillation, diabetes, total cholesterol, proteinuria, fibrinogen levels, creatinine, homocysteine, early infarct signs, antiplatelet therapy and anticoagulant therapy; In addition, we found low-certainty evidence that there may be little to no association between risk of intracranial hemorrhage and weight, sex, platelet count, uric acid, albumin and white matter hyperintensity. Leukoaraiosis, cardiovascular disease, total cholesterol, white blood cell count, proteinuria, fibrinogen levels, creatinine, homocysteine and early CT hypodensities are not included in most intracranial hemorrhage risk assessment models. CONCLUSION: This study informs risk prediction for thrombolysis-related intracranial hemorrhage, it also informs guidelines for intracranial hemorrhage prevention and future research.

18.
Bioresour Technol ; 378: 128987, 2023 Jun.
Article En | MEDLINE | ID: mdl-37001701

An anaerobic/oxic/anoxic continuous plug-flow biorereactor was established to derive stable advanced nitrogen removal of oligotrophic domestic wastewater by setting a sludge dual-reflux system and a mixed liquid cross-flow system, while extending the hydraulic retention time in anoxic section. The effluent total inorganic nitrogen was 7.9 ± 2.2 mg N/L, with removal efficiency of 84 ± 3.9%. Results of nitrogen balance calculations indicated that the contribution of simultaneous nitrification and denitrification to total inorganic nitrogen loss in oxic region was 15% during stable stage, and the total inorganic nitrogen removal by endogenous-denitrification and enhanced exogenous-denitrification in the anoxic region was 39.9%. Prolongation of hydraulic retention time in anoxic segment is the critical reason for enhancing endogenous-denitrification, and cross-flow system is an important measure to improve exogenous-denitrification. This study provides new insights into bridging the gap between energy-saving and high-level nitrogen removal from municipal wastewater with low carbon to nitrogen ratios.


Sewage , Wastewater , Denitrification , Nitrogen , Carbon , Anaerobiosis , Bioreactors , Nitrification
19.
Front Plant Sci ; 14: 1110521, 2023.
Article En | MEDLINE | ID: mdl-36818829

To initiate its development into a plant, a small dark-grown seedling (prior to its emergence from the ground) must penetrate through the growth media. The path that the seedling takes during this journey has yet to be explained. As such, we conducted non-destructive tests using CT scans to observe the growth of dark-grown seedlings in soil over time; we also developed a model to simulate the dynamics of an emerging seedling, and to examine effects of various growth medium conditions, including Lunar soil. It was previously postulated that, with gravitropism in a terrestrial growth medium, a dark-grown seedling would grow directly upright. However, our CT scan results showed that dark-grown soybean seedlings departed from the vertical path in soil, as far as a lateral distance of approximately 10 mm. The phenomenon of the non-straight path was also demonstrated by the model results. Through simulations, we found that an emerging seedling naturally weaves through the particles of growth medium, in search for the path of least resistance. As a result, the seedling ends up travelling a longer distance. Compared with a seedling that was artificially forced to take a straight path in a growth media, the seedling taking the natural path encountered significantly lower resistances (20% lower) from the growth medium, while travelled 12% longer distance during the emergence process. A seedling encountered a much higher impedance in Lunar soil. Our results suggest that taking the path of least resistance, in addition to shaping and orientating itself for mechanical advantage, are strategies evolved by plant species that have contributed to its vast success. An understanding of plant behavior and survival strategies on Earth lay the foundation for future research in agriculture in novel environments, including on celestial bodies.

20.
Adv Mater ; 35(17): e2210345, 2023 Apr.
Article En | MEDLINE | ID: mdl-36772897

Hitherto, Cu2 Se incorporated with a dispersed second phase shows extremely low thermal conductivity and excellent thermoelectric properties. However, the significant mismatch in electronic band structure between the second phases and the matrix often causes a deterioration of carrier mobility. In this work, based on density functional theory (DFT) calculations, the electronic band structure of the second phase is adjusted through doping S and Te. It is found that Cu2 Se0.88 S0.06 Te0.06 has a highly similar electronic band structure to the Cu2 Se matrix, which results in high carrier mobility and power factor in Cu2 Se-based composite materials. Additionally, the dispersed second-phase Cu2 Se0.88 S0.06 Te0.06 , dislocations, and nanograins are observed in the Cu2 Se/5 wt% Cu2 Se0.88 S0.06 Te0.06 product, which leads to a substantial reduction in the thermal conductivity. Finally, high figure of merit (zT) values of 2.04 (by Dulong-Petit heat capacity) and 2.34 (by Differential Scanning Calorimetry (DSC) measured heat capacity) are achieved at 850 K, which are about 65% higher than that of Cu2 Se in this work and comparable to the recently reported p-type Cu2 Se with outstanding performance.

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