Large harvested energy with non-linear pyroelectric modules.

Coming up with sustainable sources of electricity is one of the grand challenges of this century. The research field of materials for energy harvesting stems from this motivation, including thermoelectrics1, photovoltaics2 and thermophotovoltaics3. Pyroelectric materials, converting temperature periodic variations in electricity, have been considered as sensors4 and energy harvesters5-7, although we lack materials and devices able to harvest in the joule range. Here we develop a macroscopic thermal energy harvester made of 42 g of lead scandium tantalate in the form of multilayer capacitors that produces 11.2 J of electricity per thermodynamic cycle. Each pyroelectric module can generate up to 4.43 J cm-3 of electric energy density per cycle. We also show that two of these modules weighing 0.3 g are sufficient to sustainably supply an autonomous energy harvester embedding microcontrollers and temperature sensors. Finally, we show that for a 10 K temperature span these multilayer capacitors can reach 40% of Carnot efficiency. These performances stem from (1) a ferroelectric phase transition enabling large efficiency, (2) low leakage current preventing losses and (3) high breakdown voltage. These macroscopic, scalable and highly efficient pyroelectric energy harvesters enable the reconsideration of the production of electricity from heat.

Vishniacozyma pseudocarnescens sp. nov., a new anamorphic tremellomycetous yeast species.

Three strains belonging to the basidiomycetous yeast genus Vishniacozyma were isolated from marine water samples collected from intertidal zones in Liaoning province, northeast China. Phylogenetic analyses based on the sequences of the small subunit (SSU) ribosomal DNA (rDNA), the D1/D2 domain of the large subunit (LSU) ribosomal DNA (rDNA), the internal transcribed spacer region (ITS), the two subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1), and the mitochondrial gene cytochrome b (CYTB) showed that these strains together with 20 strains from various geographic and ecological origins from other regions of the world represent a novel species in the genus Vishniacozyma. We propose the name Vishniacozyma pseudocarnescens sp. nov. (holotype CGMCC 2.6457) for the new species, which differs phenotypically from its close relatives V. carnescens, V. tephrensis, and V. victoriae by its ability to grow at 30 °C and on 50 % (w/v) glucose-yeast extract agar.

Topological false discovery rates for brain mapping based on signal height.

Correcting the effect of multiple testing is important in statistical parametric mapping. If the threshold is too liberal, then spurious claims may flood in; if it is too conservative, then true hints may be overlooked. It is highly desirable to combine random field theory and the false discovery rate (FDR) to achieve more powerful detection under gauged topological errors. However, the current FDR method based on peak height does not fully meet this expectation, and sometimes is more conservative than the traditional family-wise error rate method, for unexplained reasons. In this paper, we introduce a new topological FDR method based on signal height. As analyzed in theory and validated with extensive experiments, it controls error rates much more accurately than the peak FDR method does, and substantially gains detection power. In addition, we discover reasons behind the peak FDR method's under-performance, and formulate equations to predict the two methods' behavior.

A Co-Precursor Approach Coupled with a Supercritical Modification Method for Constructing Highly Transparent and Superhydrophobic Polymethylsilsesquioxane Aerogels.

Polymethylsilsesquioxane (PMSQ) aerogels obtained from methyltrimethoxysilane (MTMS) are well-known high-performance porous materials. Highly transparent and hydrophobic PMSQ aerogel would play an important role in transparent vacuum insulation panels. Herein, the co-precursor approach and supercritical modification method were developed to prepare the PMSQ aerogels with high transparency and superhydrophobicity. Firstly, benefiting from the introduction of tetramethoxysilane (TMOS) in the precursor, the pore structure became more uniform and the particle size was decreased. As the TMOS content increased, the light transmittance increased gradually from 54.0% to 81.2%, whereas the contact angle of water droplet decreased from 141° to 99.9°, ascribed to the increase of hydroxyl groups on the skeleton surface. Hence, the supercritical modification method utilizing hexamethyldisilazane was also introduced to enhance the hydrophobic methyl groups on the aerogel's surface. As a result, the obtained aerogels revealed superhydrophobicity with a contact angle of 155°. Meanwhile, the developed surface modification method did not lead to any significant changes in the pore structure resulting in the superhydrophobic aerogel with a high transparency of 77.2%. The proposed co-precursor approach and supercritical modification method provide a new horizon in the fabrication of highly transparent and superhydrophobic PMSQ aerogels.

Development of the human fetal hippocampal formation during early second trimester.

Development of the fetal hippocampal formation has been difficult to fully describe because of rapid changes in its shape during the fetal period. The aims of this study were to: (1) segment the fetal hippocampal formation using 7.0 T MR images from 41 specimens with gestational ages ranging from 14 to 22 weeks and (2) reveal the developmental course of the fetal hippocampal formation using volume and shape analyses. Differences in hemispheric volume were observed, with the right hippocampi being larger than the left. Absolute volume changes showed a linear increase, while relative volume changes demonstrated an inverted-U shape trend during this period. Together these exhibited a variable developmental rate among different regions of the fetal brain. Different sub-regional growth of the fetal hippocampal formation was specifically observed using shape analysis. The fetal hippocampal formation possessed a prominent medial-lateral bidirectional shape growth pattern during its rotation process. Our results provide additional insight into 3D hippocampal morphology in the assessment of fetal brain development and can be used as a reference for future hippocampal studies.

Simulation of the tensile properties of silica aerogels: the effects of cluster structure and primary particle size.

A new two-level model is proposed to investigate the relationship between the mechanical properties and microstructure of silica aerogels. This two-level model consists of the particle-particle interaction model and the cluster structure model. The particle-particle interaction model is proposed to describe interactions between primary particles, in which the polymerization reaction between primary particles is considered. The cluster structure model represents the geometrical structure of silica aerogels, and it is established using a modified diffusion-limited colloid aggregation (DLCA) algorithm. This two-level model is used to investigate the tensile behavior of silica aerogels based on the discrete element method (DEM). The numerical results show that the primary particle size has significant effects on the elastic modulus and tensile strength of silica aerogels. Moreover, the power-law relationships between tensile properties and aerogel density are dependent on the variation of the primary particle radius with density. The present results can explain the difference among different experimental exponents to a certain extent. In comparison with experimental data within a wide density range, this two-level model provides good quantitative estimations of the elastic modulus and tensile strength of silica aerogels after the size effects of the primary particle are considered. This paper provides a fundamental understanding of the relationship between the mechanical properties and microstructure of silica aerogels. The two-level model can be extended to study the mechanical properties of other aerogels and aerogel composites.

Spatial variations impact the soil fungal communities of Larix gmelinii forests in Northeast China.

Soil fungi play a critical role in the biogeochemical cycles of forest ecosystems. Larix gmelinii is a strong and important timber tree species, which forms close associations with a wide range of soil fungi. However, the temporal-spatial disparity effects on the assembly of soil fungal communities in L. gmelinii forests are poorly understood. To address these questions, a total of 120 samples, including 60 bulk soil and 60 root samples, were collected from Aershan and Genhe in July (summer) and October (autumn)2021. We obtained 7,788 operational taxonomic units (OTUs) after merging, filtering, and rarefying using high-throughput sequencing. The dominant phyla are Basidiomycota, Ascomycota, Mortierellomycota, and Mucoromycota. There were 13 dominant families, among which the families with average relative abundance more than 5% included Thelephoraceae, Mortierellaceae, Archaeorhizomycoaceae, and Inocybaceae. In the functional guilds, symbiotrophic fungi had a relative advantage in the identified functions, and the relative abundances of pathotrophic and saprotrophic fungi varied significantly between sites. There were 12 families differentially expressed across compartments, 10 families differentially expressed between seasons, and 69 families were differentially expressed between sites. The variation in alpha diversity in the bulk soil was greater than that in the rhizosphere soil. Among the three parts (compartment, season, and site), the site had a crucial effect on the beta diversity of the fungal community. Deterministic processes dominated fungal community assembly in Genhe, whereas stochastic processes dominated in Aershan. Soil physicochemical properties and climatic factors significantly affected fungal community structure, among which soil total nitrogen and pH had the greatest effect. This study highlights that spatial variations play a vital role in the structure and assembly of soil fungal communities in L. gmelinii forests, which is of great significance for us in maintaining the health of the forests.

Platelet-rich plasma in orthopedics: Bridging innovation and clinical applications for bone repair.

In the burgeoning domain of orthopedic therapeutic research, Platelet-Rich Plasma (PRP) has firmly established its position, transforming paradigms ranging from tissue regeneration to the management of chondral lesions. This review delves into PRP's recent integrations with cutting-edge interventions such as 3D-printed scaffolds, its role in bone and cartilage defect management, and its enhanced efficacy when combined with molecules like Kartogenin (KGN) for fibrocartilage zone repair. Significant attention is paid to tissue engineering for meniscal interventions, where a combination of KGN, PRP, and bone marrow-derived mesenchymal stem cells are under exploration. Within the sphere of osteochondral regenerative therapy, the synergy of PRP with Bone Marrow Aspirate Concentrate (BMAC) represents a noteworthy leap towards cartilage regeneration. The innovative incorporation of PRP with biomaterials like hydroxyapatite and graphene oxide further underscores its versatility in supporting structural integrity and ensuring sustained growth factor release. However, while PRP's autologous and nontoxic nature makes it an inherently safe option, concerns arising from its preparation methods, particularly with bovine thrombin, necessitate caution. As of 2023, despite the burgeoning promise of PRP in bone healing, the quest for its standardization, optimization, and substantiation through rigorous clinical trials continues. This comprehensive review elucidates the contemporary applications, challenges, and future trajectories of PRP in orthopedics, aiming to spotlight areas primed for further research and exploration.

Afforestation-Induced Shifts in Soil Bacterial Diversity and Community Structure in the Saihanba Region.

Afforestation plays a pivotal role in ecosystem restoration, exemplified by the Saihanba Mechanized Forest Farm, the world's largest planted forest; however, the assembly mechanisms and interactions of soil microbial communities in such forests remain inadequately understood. This study aimed to elucidate the impact of different afforestation tree species, namely Larix gmelinii var. principis-rupprechtii, Picea asperata, and Pinus sylvestris var. mongolica, on soil bacterial diversity and community structure in comparison to grassland. Sixty soil samples were collected at a 20 cm depth, and high-throughput sequencing was employed to identify bacterial communities and assess their interactions with environmental factors. A total of 6528 operational taxonomic units (OTUs) were identified, with Solirubrobacter, Conexibacter, Bacillus, Massilia, Gaiella, Acidibacter, and Vicinamibacter being the dominant genera. Afforestation significantly impacted soil bacterial alpha diversity, with notable influence from key soil chemical properties, including available phosphorus (AP), cation exchange capacity (CEC), and the carbon-to-nitrogen ratio of soil organic matter (SOM-C/N). The Mantel test highlighted pH, the Normalized Difference Vegetation Index (NDVI), and spatial variable (dbMEM) as primary environmental factors influencing dominant bacterial genera. The bacterial community structure demonstrated deterministic homogeneous selection, wherein SOM-C/N emerged as a significant factor influencing the dissimilarity of soil bacterial communities. Furthermore, plantation soils exhibited a more complex network structure than grassland soil, highlighting the crucial role of bacterial communities in vegetation changes and providing valuable insights into their response to environmental factors during the reforestation process.

Spatial Distribution Patterns and Assembly Processes of Abundant and Rare Fungal Communities in Pinus sylvestris var. mongolica Forests.

Revealing the biogeography and community assembly mechanisms of soil microorganisms is crucial in comprehending the diversity and maintenance of Pinus sylvestris var. mongolica forests. Here, we used high-throughput sequencing techniques and null model analysis to explore the distribution patterns and assembly processes of abundant, rare, and total fungal communities in P. sylvestris var. mongolica forests based on a large-scale soil survey across northern China. Compared to the abundant and total taxa, the diversity and composition of rare taxa were found to be more strongly influenced by regional changes and environmental factors. At the level of class, abundant and total taxa were dominated by Agaricomycetes and Leotiomycetes, while Agaricomycetes and Sordariomycetes were dominant in the rare taxa. In the functional guilds, symbiotrophic fungi were advantaged in the abundant and total taxa, and saprotrophic fungi were advantaged in the rare taxa. The null model revealed that the abundant, rare, and total taxa were mainly governed by stochastic processes. However, rare taxa were more influenced by deterministic processes. Precipitation and temperature were the key drivers in regulating the balance between stochastic and deterministic processes. This study provides new insights into both the biogeographical patterns and assembly processes of soil fungi in P. sylvestris var. mongolica forests.

Spatial-temporal atlas of human fetal brain development during the early second trimester.

During the second trimester, the human fetal brain undergoes numerous changes that lead to substantial variation in the neonatal in terms of its morphology and tissue types. As fetal MRI is more and more widely used for studying the human brain development during this period, a spatiotemporal atlas becomes necessary for characterizing the dynamic structural changes. In this study, 34 postmortem human fetal brains with gestational ages ranging from 15 to 22 weeks were scanned using 7.0 T MR. We used automated morphometrics, tensor-based morphometry and surface modeling techniques to analyze the data. Spatiotemporal atlases of each week and the overall atlas covering the whole period with high resolution and contrast were created. These atlases were used for the analysis of age-specific shape changes during this period, including development of the cerebral wall, lateral ventricles, Sylvian fissure, and growth direction based on local surface measurements. Our findings indicate that growth of the subplate zone is especially striking and is the main cause for the lamination pattern changes. Changes in the cortex around Sylvian fissure demonstrate that cortical growth may be one of the mechanisms for gyration. Surface deformation mapping, revealed by local shape analysis, indicates that there is global anterior-posterior growth pattern, with frontal and temporal lobes developing relatively quickly during this period. Our results are valuable for understanding the normal brain development trajectories and anatomical characteristics. These week-by-week fetal brain atlases can be used as reference in in vivo studies, and may facilitate the quantification of fetal brain development across space and time.

Seasonal variation in the soil fungal community structure of Larix gmelinii forests in Northeast China.

Soil fungi play an indispensable role in forest ecosystems by participating in energy flow, material circulation, and assisting plant growth and development. Larix gmelinii is the dominant tree species in the greater Khingan Mountains, which is the only cold temperate coniferous forest in China. Understanding the variations in underground fungi will help us master the situation of L. gmelinii above ground. We collected soil samples from three seasons and analyzed the differences in soil fungal community structure using high-throughput sequencing technology to study the seasonal changes in soil fungal community structure in L. gmelinii forests. We found that the Shannon and Chao1 diversity in autumn was significantly lower than in spring and summer. The community composition and functional guild varied significantly between seasons. Furthermore, we showed that ectomycorrhizal fungi dominated the functional guilds. The relative abundance of ectomycorrhizal fungi increased dramatically from summer to autumn and was significantly negatively correlated with temperature and precipitation. Temperature and precipitation positively affect the alpha diversity of fungi significantly. In addition, pH was negatively correlated with the Chao1 diversity. Temperature and precipitation significantly affected several dominant genera and functional guilds. Among the soil physicochemical properties, several dominant genera were affected by pH, and the remaining individual genera and functional guilds were significantly correlated with total nitrogen, available phosphorus, soil organic carbon, or cation exchange capacity. For the composition of total fungal community, temperature and precipitation, as well as soil physicochemical properties except AP, significantly drove the variation in community composition.

High cooling performance in a double-loop electrocaloric heat pump.

Cooling through solid-state electrocaloric materials is an attractive replacement for vapor compression. Despite recent efforts, devices that are potentially commercially competitive have not been developed. We present an electrocaloric cooler with a maximum temperature span of 20.9 kelvin and a maximum cooling power of 4.2 watts under the moderate applied electric field of 10 volts per micrometer without any observed breakdown. Moreover, the maximum coefficient of performance, even taking into account energy expended on fluid pumping, reaches 64% of Carnot's efficiency as long as energy is properly recovered. We believe that this demonstration shows electrocaloric cooling to be a very promising alternative to vapor compression cooling.

[Floral composition and ecological distribution of wood-decaying fungi in Laojunshan National Park, Southwest China]. / ä¸½æ±Ÿè€å›å±±å›½å®¶å ¬å›­æœ¨è çœŸèŒåŒºç³»ç»„æˆä¸Žåˆ†å¸ƒç‰¹å¾.

Wood-decaying fungi are important components of forest ecosystem, mainly growing on the dead wood and decomposing lignin, cellulose, and hemi-cellulose. Understanding the ecological distribution of wood-decaying fungi are necessary to reveal their ecological function. In this study, we investigated wood-decaying fungi at three sites with different altitudes in Laojunshan National Park. Fruit bodies of fungi were collected and identified based on morphological and molecular analy-sis. In total 68 species were recorded, belonging to 40 genera, 21 families and 8 orders. Polyporaceae, Fomitopsidaceae, and Hymenochaetaceae were dominant families. The floral composition showed a distinct north temperate character, which was the most important element among all the bio-geographical elements with the highest percentage of 38.2%. These wood-decaying fungi can be divided into two ecological types: saprophytic (63 species) and ectomycohizal (5 species). Among these saprophytic fungi, 51 species could cause white rot and 12 species cause brown rot. The amounts of fungal species in deciduous broad-leaf forest (DBF), coniferous broad-leaved mixed forest (CBMF) and dark coniferous forest (DCF) were 34, 26 and 22, respectively. Postia fragilis and Stereum hirsutum, distributed in all the three types of forests, were dominant species of Laojunshan National Park.

Remarkably Enhanced Negative Electrocaloric Effect in PbZrO3 Thin Film by Interface Engineering.

The electrocaloric effect in ferroelectric materials has drawn much attention due to its potential applications in integrated circuit cooling and novel cooling devices. In contrast to the widely researched positive electrocaloric effect, the negative electrocaloric effect has received much less attention due to the lack of any effective methods for significant enhancement. In this work, we fabricated PbZrO3 thin film on a Pt/Si substrate by the sol-gel method. By controlling the interface conditions between the thin film and substrate, we induced defects into the interface and stabilized a transient ferroelectric phase in the PbZrO3 thin film. The emergence of the transient ferroelectric phase postpones the antiferroelectric-ferroelectric phase transition. As a result, a negative electrocaloric effect up to -18.5 K is estimated near room temperature, the highest one ever reported in this temperature range. This result suggests a new strategy to enhance the negative electrocaloric effect and may benefit the application of PbZrO3 thin films in cooling devices.

Precise segmentation of densely interweaving neuron clusters using G-Cut.

Characterizing the precise three-dimensional morphology and anatomical context of neurons is crucial for neuronal cell type classification and circuitry mapping. Recent advances in tissue clearing techniques and microscopy make it possible to obtain image stacks of intact, interweaving neuron clusters in brain tissues. As most current 3D neuronal morphology reconstruction methods are only applicable to single neurons, it remains challenging to reconstruct these clusters digitally. To advance the state of the art beyond these challenges, we propose a fast and robust method named G-Cut that is able to automatically segment individual neurons from an interweaving neuron cluster. Across various densely interconnected neuron clusters, G-Cut achieves significantly higher accuracies than other state-of-the-art algorithms. G-Cut is intended as a robust component in a high throughput informatics pipeline for large-scale brain mapping projects.

Bayesian network modeling for discovering "dependent synergies" among muscles in reaching movements.

The coordinated activities of muscles during reaching movements can be characterized by appropriate analysis of simultaneously-recorded surface electromyograms (sEMGs). Many recent sEMG studies have analyzed muscle synergies using statistical methods such as Independent Component Analysis, which commonly assume a small set of influences upstream of the muscles (e.g., originating from the motor cortex) produce the sEMG signals. Traditionally only the amplitude of the sEMG signal was investigated. Here, we present a fundamentally different approach and model sEMG signals after the effects of amplitude have been minimized. We develop the framework of Bayesian networks (BNs) for modeling muscle activities and for analyzing the overall muscle network structure. Instead of assuming that synergies may be independently activated, we assume that neuronal activity driving a given muscle may be conditionally dependent upon neurons driving other muscles. We call the resulting interactions between muscle activity patterns "dependent synergies". The learned BN networks were explored for the purpose of classification across subjects based on hand dominance or affliction by stroke. Network structure features were investigated as classification input features and it was determined that specific edge connection patterns of 3-node subnetworks were selectively recruited during reaching movements and were differentially recruited after stroke compared to normal control subjects. The resulting classification was robust to inter-subject and within-group variability and yielded excellent classification performance. The proposed framework extends muscle synergy analysis and provides a framework for thinking about muscle activity interactions in motor control.

[An association study between paranoid schizophrenia and four genes involved in dopamine metabolism].

Schizophrenia is a complex disease caused by interactions among multiple genes. Reports of one of its susceptibility genes, ethyltracatechol-O-mnsferase (COMT) have been conflicting. In the present study on paranoid schizophrenia, we have performed a multilocus association study to analyze the interactions among 4 genes that are involved in dopamine metabolism. Result supports the hypothesis that COMT-136-BclI regulates Val108/158Met. When the genotype of the former is CC, Met (A) is the genotype of susceptibility allele Val108/158Met; and when the genotype of the former is GG, Val (G) is the genotype of susceptibility allele Val108/158Met. This new hypothesis may explain the conflicting results about Val108/158Met (COMT) obtained by single-locus analyses. It also illustrates that multilocus analysis is necessary for the research of complex diseases.

Transformation Invariant Control of Voxel-Wise False Discovery Rate.

Multiple testing for statistical maps remains a critical and challenging problem in brain mapping. Since the false discovery rate (FDR) criterion was introduced to the neuroimaging community a decade ago, many variations have been proposed, mainly to enhance detection power. However, a fundamental geometrical property known as transformation invariance has not been adequately addressed, especially for the voxel-wise FDR. Correction of multiple testing applied after spatial transformation is not necessarily equivalent to transformation applied after correction in the original space. Without the invariance property, assigning different testing spaces will yield different results. We find that normalized residuals of linear models with Gaussian noises are uniformly distributed on a unit high-dimensional sphere, independent of t-statistics and F-statistics. By defining volumetric measure in the hyper-spherical space mapped by normalized residuals, instead of the image's Euclidean space, we can achieve invariant control of the FDR under diffeomorphic transformation. This hyper-spherical measure also reflects intrinsic "volume of randomness" in signals. Experiments with synthetic, semi-synthetic and real images demonstrate that our method significantly reduces FDR inconsistency introduced by the choice of testing spaces.