Weak Aggregation Research Articles

Influence of crop rotation, irrigation, fertilization, and tillage on the aggregate property and soil wind erosion potential in the floodplain of the Yellow River

The floodplain of the Yellow River (FPYR) is threatened by severe soil erosion. Soils are often susceptible to wind erosion owing to their coarse-textures and weak aggregation, yet studies are yet to describe the ability of soils to resist wind erosion in this region. Accordingly, this study aimed to quantify how soil wind erosion potential is affected by soil aggregate properties, such as dry aggregate geometric mean diameter (GMD), aggregate geometric standard deviation (GSD), aggregate stability, and soil bulk density, and to assess the effects of soil type, crop rotation, irrigation, fertilization, and tillage treatments on these aggregate properties in the main wind erosion area across the FPYR. Significant differences in GMD and aggregate stability were found between crop rotation treatments, whereas crop rotation marginally affected the soil bulk density. Further, the impact of management practices on aggregate properties differed for each soil type. The soil aggregate erodible fraction (EF) in the FPYR ranged from 1.14 to 82.73% across sites, with a mean of 26.14% across soil types and management practices, which was lower than that previously reported in other wind erosion regions. We incorporated these measured EFs into the Revised Wind Erosion Equation (RWEQ) to evaluate the wind erosion risk of the FPYR. The results indicated that the central FPYR was more susceptible to wind erosion than the other regions, although the total wind erosion potential in the FPYR was small. Adoption of soil conservation practices could help minimize wind erosion and improve atmospheric quality in the region.

Low gelatin concentration assisted cellulose nanocrystals stabilized high internal phase emulsion: The key role of interaction

Low concentrations of gelatin (0.02–0.20 wt%) were applied to regulate the surface and interface properties of CNC (0.50 wt%) by forming CNC/G complexes. As gelatin concentration increased from 0 to 0.20 wt%, the potential value of CNC/G gradually changed from −44.50 to −17.93 mV. Additionally, various gelatin concentrations led to micromorphology changes of CNC/G complexes, with the formation of particle interconnection at gelatin concentration of 0.10 wt%, followed by network structure and enhanced aggregation at gelatin concentration of 0.15 and 0.20 wt% respectively. The water contact angle (25.91°-80.23°) and interface adsorption capacity of CNC/G were improved due to hydrophobic group exposure of gelatin. When gelatin concentration exceeded 0.10 % at a fixed oil phase volume fraction (75 %), a high internal phase emulsion (HIPE) stabilized by CNC/G can be formed with a good storage stability. The rheological and microstructure results of HIPE confirmed that low gelatin concentration can assist CNC to form stable emulsion structure. Especially, the auxiliary stabilization mechanism of various gelatin concentration was different. CNC/G-0.10 % and CNC/G-0.15 % stabilized HIPE mainly depended on the enhanced interface adsorption and network structure, while CNC/G-0.20 % stabilized HIPE mainly relied on enhanced interface adsorption/accumulation due to weak electrostatic repulsion and aggregate granular morphology of CNC/G-0.20 %.

Simulation and analysis of enhancement-mode AlGaN/GaN HEMT with P-I-N junction gate

To improve the threshold voltage and gate reliability of conventional enhancement-mode p-GaN-gated AlGaN/GaN high electron mobility transistors while maintaining a low on-resistance, an improved design solution for p-GaN HEMTs with P-I-N junction gate (PIN-HEMTs) has been proposed. Simulation results show that energy band modulation is achieved by adjusting the doping concentration and thickness of each layer of the PIN junction, and high-performance p-GaN gate HEMTs with adjustable threshold voltages ranging from 0.56 V to 4.75 V and gate breakdown voltages ranging from 19.8 V to 30.3 V would be prepared. The PIN-HEMT has a quasi-self-alignment property, which means that good gate control is independent of gate metal alignment. This not only improves the production efficiency but also solves the problems of weak gate control and electric field aggregation at the gate edge caused by the gate misalignment in conventional p-GaN gate HEMTs, thus realizing lower on-resistance and higher gate breakdown voltage, which demonstrates this proposed structure has excellent potentials for realizing effective and reliable high-power transistors.

Family aggregation and prevalence of other autoimmune diseases in SAPHO syndrome

ObjectiveSAPHO (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) syndrome is a heterogeneous disease that clinically manifests as chronic inflammatory osteoarticular and dermatological lesions. Few reports have described familial clustering of SAPHO syndrome cases. This research aimed to illustrate the family aggregation of SAPHO syndrome and investigate the prevalence of autoimmune disorders among SAPHO syndrome patients and first-degree relatives in a large cohort. MethodsWe retrospectively reviewed the medical records of 233 SAPHO patients diagnosed at Peking Union Medical College Hospital. Direct phone calls were made to each first-degree relatives. All relatives of the patients who reported SAPHO syndrome were asked for a detailed outpatient evaluation. ResultsA total of 233 patients and 1227 first-degree relatives were recruited. Six (2.6 %) patients had positive SAPHO family history, including four mother-daughter pairs and two sister pairs. Twenty-one (9.0 %) patients presented at least one kind of autoimmune disease, including 12 rheumatoid arthritis and 4 ulcerative colitis cases. Fifty-eight (24.9 %) SAPHO syndrome patients had 68 (5.5 %) first-degree relatives with at least one autoimmune disorder. The palmoplantar pustulosis, psoriasis vulgaris, and rheumatoid arthritis prevalence in our subjects were each higher than reference rates. ConclusionThis is the first evaluation of familial aggregation for SAPHO syndrome in a large cohort. SAPHO syndrome has a weak familial aggregation. There is a relatively high prevalence of coexisting autoimmune disease among patients with SAPHO syndrome and their first-degree relatives. These results would prompt physicians to screen SAPHO syndrome patients and their family members for concomitant autoimmune diseases. KeypointsThis study suggesting a potential genetic component in the pathogenesis of SAPHO syndrome. This study is the first to evaluate the family aggregation of SAPHO syndrome in a large cohort.

The role of lipids in determining the gas cell structure of gluten-free steamed oat cake

The stabilization of gas cells is crucial to obtain cake or bread products with a homogeneous crumb and is mainly depends on the proteins, starches, and lipids. Oats, in particular, are known for their high lipid content compared to other grains. However, the specific contribution of oat lipids to the gas chamber structure in gluten-free steamed oat cake is still unclear. Hence, to elucidate the potential mechanism involved, this study aimed to investigate the steaming characteristics of oat dough, as well as the protein-starch network matrix (including protein aggregation and structural properties), and the air/water interfacial characteristics (including foaming and surface tension properties) of oat dough liquor subjected to different defatting treatments. Results showed that by moderately removing lipids from samples (particularly ROF-D3 with 2.91% lipid content), gas retention ability, cell area fraction, and specific volume of the steamed oat cake were enhanced, which were 93.30 mL/100 mL, 36.27%, and 2.72 mL/g, respectively. Weak protein aggregation and an ordered protein secondary structure corresponding to a more open and stable protein network structure were observed in the ROF-D3 sample caused by moderate lipid removal. In addition, moderate removal of lipids obviously increased the extraction yield of oat dough liquor, in which lipid was evidently the dominant component. Compared to the ROF-D1 sample, the enhanced quality of the ROF-D3 sample can be attributed to the strongest foam stability and the increased air-water interface surface tension.

1,8-diphenyl-carbazole-based boron, sulfur-containing multi-resonance emitters with suppressed aggregation emission for narrowband OLEDs

Multi-resonance emitters are attractive for organic light-emitting diode (OLED) applications because of their narrowband emissions and high photoluminescent efficiencies. Nevertheless, their tendency to aggregation by intermolecular interactions could cause doping sensitivity and reduce color purity at high concentrations. Here, we report a novel boron, sulfur (B, S)-containing multi-resonance emitter (BSS-Ph-TBCz) consisting of 1,8-diphenyl-carbazole substituent at para-position of boron atom of B, S-doped polycyclic aromatic skeleton. Different from control compound (BSS-TBCz) containing conventional carbazole substituents showing aggregation-caused spectral broadening, BSS-Ph-TBCz with 1,8-diphenyl-carbazole group exhibits weak intermolecular aggregation behavior owing to the large twist angle between polycyclic skeleton and carbazole plane caused by two steric phenyl groups on carbazole group, leading to nearly unchanged emissions with small full width at half-maximum of 30–31 nm at doping concentration ranging from 1 to 100 wt%. OLEDs employing BSS-Ph-TBCz as emitter reveal blue electroluminescence at 468 nm and maximum external quantum efficiency of 21.4% at 5 wt% doping concentration, which remains at 20.1% at high doping concentration of 25 wt%.

Proteolytically Stable ααγ-Hybrid Peptides Inhibit the Aggregation and Cytotoxicity of Aβ42.

The recent approval of antibody-based therapy for targeting the clearance of amyloid plaques fuels the research in designing small molecules and peptide inhibitors to target the aggregation of Aβ-peptides. Here, we report that the 15-residue ααγ-hybrid peptide not only inhibits the aggregation of soluble Aβ42 into fibrils but also disintegrates the aggregated Aβ42 fibrils into smaller assemblies. Further, the hybrid peptide completely rescues neuronal cells from the toxicity of Aβ42 at equimolar concentrations. The shorter 10- and 12-mer peptides showed weak aggregation inhibition activity, while the fully hydrophobic 15-mer ααγ-hybrid peptide analogue showed no aggregation inhibition activity. Further, the 15-mer ααγ-hybrid peptide showed resistance against trypsin digestion and also nontoxic to the neuronal cells. The CD revealed that the peptide upon interaction induces a helix-type conformation in the Aβ42. This is in sharp contrast to the β-sheet conformation of Aβ42 upon incubation. The two-dimensional-NMR (2D-NMR) analysis revealed a large perturbation in the chemical shifts of residues at the N-terminus. The presence of 15-mer peptide at an equimolar concentration of Aβ42 showed less tendency for aggregation and also exhibited nontoxicity to the neuronal cells. The results reported here may be useful in designing new therapeutics for Alzheimer's disease.

Characterisation of locust bean gum with asymmetric flow field-flow fractionation (AF4) and light scattering

We present a detailed characterisation of locust bean gum (LBG), an industrially significant galactomannan, utilising asymmetric flow field-flow fractionation (AF4) and light scattering. Molecular weight and size determination of galactomannans is complicated by their tendency to aggregate, even in dilute solutions; AF4 allows us to confirm the presence of aggregates, separate these from well-dispersed polymer, and characterise both fractions. For the dispersed polymer, we find Mw=9.2×105 g mol−1 and Rg,z=82.1 nm; the distribution follows Flory scaling (Rg∼Mν) with ν∼ 0.63, indicating good solvent conditions. The aggregate fraction exhibited radii of up to 1000 nm and masses of up to 3×1010 g mol−1. Furthermore, we demonstrate how both fractions are influenced by changes to filtration procedure and solvent conditions. Notably, a 200 nm nylon membrane effectively removes the aggregated fraction; we present a concentration-dependent investigation of solutions following this protocol, using static and dynamic light scattering, which reveals additional weak aggregation in these unfractionated samples. Overall, we demonstrate that AF4 is highly suited to LBG characterisation, providing structural information for both well-dispersed and aggregated fractions, and expect the methods employed to apply similarly to other galactomannans and associating polymer systems.

Physical aspects of magnetic nanoparticle manipulation in environmental and biomedical applications

Microfluidic manipulation of magnetic nanoparticles (MNPs) is a smart tool for various environmental and biomedical applications. Unfortunately, these techniques have a strong limitation related to the low efficiency of magnetic manipulation of MNPs due to their Brownian motion. However, molecules adsorbed on the surface of MNPs can cause their weak (primary) aggregation. Once the magnetic field is applied, the magnetic force exerted on the primary aggregates will be strongly amplified allowing for significant improvement of the remote control over the MNPs by the magnetic fields. In this paper, we check this concept on three different physicochemical systems covering different application: (i) methylene blue cationic dye adsorbed on citrate coated MNPs for water purification; (ii) curcumin bound to the β-cyclodextrin modified MNPs for magnetic drug delivery; (iii) antigens bound to MNPs decorated with antibodies for model immunoassays. We find striking similarities of the magnetic-field induced behaviours of these different systems, with the dipolar coupling parameter, the supersaturation, the Mason number and the Peclet number being the main governing parameters. We also mention the possibility of using this concept for enhancement of the convective drug transport through the blocked blood vessels.

Skin-like cryogel electronics from suppressed-freezing tuned polymer amorphization

The sole situation of semi-crystalline structure induced single performance remarkably limits the green cryogels in the application of soft devices due to uncontrolled freezing field. Here, a facile strategy for achieving multifunctionality of cryogels is proposed using total amorphization of polymer. Through precisely lowering the freezing point of precursor solutions with an antifreezing salt, the suppressed growth of ice is achieved, creating an unusually weak and homogenous aggregation of polymer chains upon freezing, thereby realizing the tunable amorphization of polymer and the coexistence of free and hydrogen bonding hydroxyl groups. Such multi-scale microstructures trigger the integrated properties of tissue-like ultrasoftness (Young’s modulus <10 kPa) yet stretchability, high transparency (~92%), self-adhesion, and instantaneous self-healing (<0.3 s) for cryogels, along with superior ionic-conductivity, antifreezing (−58 °C) and water-retention abilities, pushing the development of skin-like cryogel electronics. These concepts open an attractive branch for cryogels that adopt regulated crystallization behavior for on-demand functionalities.

Brain Connectome Imaging Markers Research of Glucose Metabolism in the Early Stage of Alzheimer's Disease.

In recent years, increasing evidence had suggested that subjective cognitive decline (SCD) in unimpaired individuals may be the first symptom of Alzheimer's disease (AD). This study investigated the differences in the glucose metabolism network and the influence of the Apolipoprotein E (ApoE) gene between the SCD and normal control (NC) group by using graph theory. In this study, we included 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) scans from Xuanwu Hospital in Beijing, China. 85 SCD subjects and 74 NC subjects were included. First, we calculated and compared network parameters between the two groups. We then identified the bilateral insula and bilateral parahippocampal gyrus as seed sites and studied the connections to the whole brain. The results showed that both the SCD and the NC showed small-world nature, but the metabolic network of SCD tended to be more regular. The clustering coefficient and local efficiency of SCD were significantly higher than those of NC (P<0.05). In addition, we found that carrying APOE resulted in enhanced metabolic connectivity, but with weaker aggregation and local information exchangeability. Our results suggested that there are differences in the glucose metabolic brain network between SCD and NC, suggesting that the graph-theoretic analysis method may provide evidence for the early pathological mechanism of AD.Clinical relevance- This study suggests that the graph-theoretic analysis method may provide evidence for the early pathological mechanism of AD.

Research on Diesel Engine Fault Status Identification Method Based on Synchro Squeezing S-Transform and Vision Transformer.

The reliability and safety of diesel engines gradually decrease with the increase in running time, leading to frequent failures. To address the problem that it is difficult for the traditional fault status identification methods to identify diesel engine faults accurately, a diesel engine fault status identification method based on synchro squeezing S-transform (SSST) and vision transformer (ViT) is proposed. This method can effectively combine the advantages of the SSST method in processing non-linear and non-smooth signals with the powerful image classification capability of ViT. The vibration signals reflecting the diesel engine status are collected by sensors. To solve the problems of low time-frequency resolution and weak energy aggregation in traditional signal time-frequency analysis methods, the SSST method is used to convert the vibration signals into two-dimensional time-frequency maps; the ViT model is used to extract time-frequency image features for training to achieve diesel engine status assessment. Pre-set fault experiments are carried out using the diesel engine condition monitoring experimental bench, and the proposed method is compared with three traditional methods, namely, ST-ViT, SSST-2DCNN and FFT spectrum-1DCNN. The experimental results show that the overall fault status identification accuracy in the public dataset and the actual laboratory data reaches 98.31% and 95.67%, respectively, providing a new idea for diesel engine fault status identification.

Spatial Pattern and Drivers of China’s Public Cultural Facilities between 2012 and 2020 Based on POI and Statistical Data

In the context of globalization and the intensification of international competition, the construction of public cultural facilities has long been not limited to meeting the cultural needs of the people but has become an important initiative to shape the competitiveness of cities. This paper collected POI and socio-economic statistics from 2012 to 2020 from 285 Chinese cities and employed the coefficient of variation (CV), Gini index (GI), ESDA, and GeoDetector to analyze the spatial patterns and driving mechanisms of public cultural facilities. Findings: (1) Public cultural facilities in Chinese cities were featured by evident regional gradient differences and uneven spatial distributions, with a CV greater than 1.3 and a GI greater than 0.5 in both years. They also showed signs of aggregation at weak levels, with a Moran I of 0.15 in both years and a cluster pattern of “hot in the east and cold in the west”. (2) Different types of public cultural facilities had differences in their differentiation, aggregation, and change trends. The CV changed from 1.39~2.69 to 1.06~1.92, and the GI changed from 0.53~0.80 to 0.47~0.62, with the differentiation of libraries, museums, theaters, art galleries, and cultural centers decreasing gradually, while that of exhibition halls increased day by day. As the Moran I increased from 0.08~0.20 to 0.12~0.24, libraries, museums, art galleries, and cultural centers showed weak aggregation with an increasingly strong trend. Theaters and exhibition halls also showed weak aggregation but in a declining trend, with the Moran I changing from 0.15~1.19 to 0.09~0.1. (3) The five driving variables exhibit significant differences in their strength across time and across regions, with the economic and infrastructure factors being the strongest and the urbanization factor the weakest. There are significant differences in the strength of the driving forces among the factors, with the total retail sales of consumers, the number of subscribers to internet services, regular higher education institutions, and undergraduates in regular HEIs playing both direct and interactive roles as the core factors. (4) The 285 cities in China are divided into four policy zonings of star, cow, question, and dog cities. Star cities should maintain their status quo without involving too much policy intervention, whereas the core and important factors should be the focus of policy in dog cities and cow cities, and the auxiliary factors should be the focus of policy in question cities. This paper contributes to the in-depth knowledge of the development pattern of public cultural facilities and provides a more refined basis for the formulation of public cultural facility promotion policies in China and similar countries.

Aggregating fluids under centrifugal fields

We present a general theoretical framework designed to interpret the effect of centrifugation of ternary fluids that exhibit weak aggregation. The model includes a buoyancy term with thermodynamic description given by a Flory-Huggins model of ternary systems containing a hydrotrope. The system octanol-ethanol-water used as a numerical example is one of several ternary systems that exhibit dynamic aggregates even far from the critical point and undergo a spontaneous emulsification upon dilution with water (Ouzo effect). The model proposes an explanation from first principles of an increased responsiveness to the centrifugal fields. We illustrate the usage of this system in intensified extraction efficiency of hydrophobic solutes that is at the basis of the dispersive liquid-liquid extraction, and show that its capabilities can be extended from analytical to continuous preparative extraction.

Polythiophene-based terpolymers with modulated aggregation behaviors for high-performance organic solar cells with 16.6% efficiency

Polythiophenes (PTs) are an attractive class of polymer donors (PDs) for organic solar cells (OSCs) owing to their relatively simple structures and scalable synthesis. Herein, a series of chlorinated thiazole-incorporated PT terpolymers are designed and high-performance OSCs with a power conversion efficiency (PCE) of 16.6% are demonstrated. By incorporating two different units, 3,3′-difluoro-2,2′-bithiophene (T2F2) and thieno[3,2-b]thiophene (TT), the aggregation properties of the terpolymers (PTz-FX; X = 0, 30, 50, 70, and 100, where X represents the mole percentage of T2F2 to total T2F2 +TT) are modulated. Among the PTz-FX series, PTz-F70 is found to be the optimal PD because its suitably tuned aggregation property leads to an optimized blend morphology with well-developed crystalline structures and donor–acceptor intermixed domains. The balanced morphology not only promotes charge generation/transport but also suppresses charge recombination in OSC devices. Thus, the PTz-F70-based OSCs achieve the highest PCE (16.6%), outperforming the OSCs based on PTz-FX with extremely strong (PTz-F100, PCE = 14.7%) or weak (PTz-F0, PCE = 12.0%) aggregation properties. The PCE of the PTz-F70-based OSCs is one of the highest performances among PT-based binary OSCs. This study highlights the importance of controlling the aggregation property of PTs for achieving high-performance PT-based OSCs.

Effect of incorporating an asymmetric electron-richer dithieno[3,2-b:2ʹ,3ʹ-d]pyrrole moiety into perylene-diimide-based polymer backbone on the optoelectronic and photovoltaic properties

Asymmetric 5-H-dithieno[3,2-b:2′,3′-d]pyran (DTP) possessing the stronger electron-donating ability than its analogue 4H-cyclopenta[2,1-b:3,4-bʹ]dithiophene (CPDT) was widely applied in fullerene-based solar cells and/or constructed the A-D-A type nonfullerene-based small molecular acceptors. However, limited efforts have devoted to develop perylene-diimide (PDI)-based polymeric acceptors in the field of all-polymer solar cell (All-PSCs). Herein, two donor-acceptor (D-A) type N,N-bis(2-hexyldecyl)-PDI-based polymer acceptors, PPDI-CPDT and PPDI-DTP utilizing 4,4-bis(2-ethylhexyl)-CPDT and 5,5-bis(4-hexylphenyl)-DTP as D moiety, were synthesized. Replacing CDT donor moiety with DTP led to the decreased thermal- and photo-stability. Regardless of an enhanced absorption around 500 nm and 0.02 eV up-shifted ELUMO, however, decreased VOC from 0.79 to 0.56 V and down-shifted JSC from 8.18 to 1.89 mA cm−2, fallen FF from 40.80% to 28.48% and thus 87.79% decreased PCE from 2.62% to 0.30% were observed. The great drop of device efficiency was mainly attributed to the weak aggregation and interaction as a result of inserting the large electronegative oxygen into the inner penta-ring of CPDT unit, which resulted in insufficient separation and restricted the photocurrent and efficient charge transfer process. These researching results suggested that it should be cautious to introduce the strong electron-rich moiety to tune the optoelectronic property and aggregation for obtaining the boosted device efficiency in All-PSCs.

Ordered mesoporous carbons from liquefied wood: Morphological effects of nucleation and growth processes

A HCl concentration-controlled hydrothermal/soft-templating strategy is proposed to prepare ordered mesoporous carbons (OMCs) with diverse morphologies from flakes to gyroids then to spheres by using liquefied wood as a carbon precursor. The effect of nucleation and growth process on morphology change was systematically studied. Results showed that an accelerated nucleation rate and a transformation of self-assembly pattern from slow and weak aggregates to fast and strong assembly are achieved in accordance with increasing HCl concentration. Detailed mechanism studies reveal that a reaction solution without seed nuclei formed at the initial stage of the hydrothermal process under low HCl concentration will lead the micelles to slowly self-assemble into microscale flakes, whereas a high HCl concentration will make the micelles rapidly self-assemble into rodlike micelles and further grow along the surface of the initially formed seed nuclei to produce nanoscale products with an annular structure. The OMCs with highly ordered p6mm mesostructure synthesized at a proper HCl concentration of 1.61 M exhibit higher electrochemical performance than the less ordered OMCs. The detailed study of nucleation and growth mechanism provides new understanding of controllable design and synthesis of OMCs with desired morphology.

Measuring urban sustainability performance through composite indicators for Spanish cities

The role that cities play in the transition to more sustainable growth is gaining increasing recognition. Measuring progress towards sustainable urban development requires quantifying this multi-dimensional phenomenon with the help of composite indicators. The purpose of this study is to propose an integrated approach to build a sustainable cities’ interval of composite indicators that rely on the Sustainable Development Goals (SDGs) framework. In addition, we propose to overcome the problem of calculating a single number by constructing a strong-weak sustainability performance interval depending on the choice of the compensability level in the aggregation stage of individual indicators. One of the advantages of this interval is that it provides information on both the average performance and the worst value of the set of indicators considered for each SDG. Moreover, it also extends the analysis for the people, planet, prosperity, peace, and partnership dimensions defined by the 2030 Agenda. As an example of application, we constructed these intervals for 50 Spanish cities, which are provincial capitals. This application lets us get a more accurate vision that can serve as a valuable tool for better urban planning design. • SDGs-based composite indicators foster knowledge and insight on urban sustainability. • Monitoring SDGs performance by an interval of composite indicators support urban planning. • Strong and weak aggregation rules are applied to deal with compensability among criteria. • Warning signals on the SDGs low performance are highlighted by the lower bound of the interval. • A comprehensive picture of urban sustainability for 50 Spanish capitals of province is provided.

Spatial relationships of trees in middle taiga post-pyrogenic pine forest stands in the European North-East of Russia

Information on the structural organization of forest stands obtained on sample plots is the basis for long-term monitoring of post-fire pine forest structure and dynamics in the European North-East. These data can be used as a marker of native pine stands of the European taiga. Here, we studied vertical and horizontal structure in the post-pyrogenic pine forests of Vacciniosum, Vaccinioso-cladinosum and Myrtillosum site types in the boreal forest of the Komi Republic. The type of horizontal structure of uneven-aged forest stands changed with age from grouped to random one. Large trees were randomly distributed on the plot. We observed the weak aggregation of undergrowth trees (natural tree regeneration) in stands at distances of 2–6 m. Undergrowth individuals were characterized by group distribution at smaller distances than 1–2 m. Spatial relationships between large, small and codominant trees demonstrated random distribution in most cases. Undergrowth individuals did not show any competitive relations. However, we revealed a “taking off” effect between mature trees of pine and pine undergrowth. The direction of the displacement of tree crown centre projections relative to the bases of their trunks was ambiguous. The shift of the crown space towards the maximum solar radiation was detected in a thinned stand with old age and big size of trees. In other site types, no one-sided orientation of the tree crown development emerged.

Preparation, characterization, and bioactivity of Zingiber officinale Roscoe powder-based Pickering emulsions.

Biocompatible Pickering emulsions (PE) stabilized by tailor-made antioxidant-loaded particles have been known for some time now, but antioxidant-rich natural plant particle-based emulsions are much less well known. This study aimed to investigate the physico-chemical properties of commercial Zingiber officinale powders obtained from biological and conventional agricultural practice and ginger powder-based PE. The physico-chemical and biological properties of Zingiber officinale powders (GDPs) obtained from conventional (GDPC1 and GDPC2) and biological agricultural (GDPBIO) practices, and the properties of derived PE (PE_GDPs) were examined. All GDPs showed weak aggregation in aqueous media and a sufficiently hydrophobic surface to stabilize oil-in-water (O/W) PE against coalescence for at least 1 month. Zingiber officinale powders (2% w/w) derived from biological agricultural practices (GDPBIO) demonstrated the best emulsifying properties. The Zingiber officinale powders and PE_GDPs were also characterized by their phytochemical profiles. All the investigated samples exhibited ferric reducing ability power greater than the positive control, butylated hydroxytoluene (BHT), with values ranging from 91.21 to 102.63 μmol L-1 Fe (II) g-1 for GDPC2 and 05PE_GDPC1 (O/W=1:1), respectively. In β-carotene bleaching test the following trend GDPC1 > GDPBIO > GDPC2 was observed. A 05PE_GDPBIO sample with the oil volume fraction equal to 50% was stable to oxidation and exhibited a promising α-amylase inhibitory activity. The results suggest that ginger powder should be used as a starting point to design biocompatible PEs for different applications in the functional food, nutraceutical, and pharmaceutical industries. In fact, powder and based PE are characterized by a promising antioxidant activity, carbohydrate hydrolyzing enzyme and lipase inhibitory properties. Further in vivo studies are necessary to confirm these findings. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.