The mediating effect of nutrition on oral frailty and fall risk in community-dwelling elderly people.

BACKGROUND: Population aging is accelerating, particularly in Asian countries. Falls are the leading cause of unintentional injuries in the elderly over 60 years old in China. Hence, it is crucial to anticipate the risk factors associated with fall risk. We aimed to explore whether oral frailty and fall risk were reciprocally related and whether nutrition mediated their association. METHODS: From October 2022 to March 2023, a total of 409 elderly individuals from the Yangzhou community were selected using the convenience sampling method. Cross-sectional data on older adults' oral frailty, nutrition, and fall risk were collected using questionnaires. Data analysis was performed using SPSS 27.0 and PROCESS macro. RESULTS: The fall risk score was 1.0 (ranging from 0 to 4.0), with 107 cases (26.2%) identified as being at risk of falling. Spearman correlation analysis revealed a positive correlation between oral frailty and the risk of falls (rs = 0.430, P < 0.01). Nutrition was found to have a negative correlation with both oral frailty and fall risk (rs=-0.519、-0.457, P < 0.01). When controlling for covariates, it was observed that nutrition mediated the relationship between oral frailty and falls. The mediating effect value accounted for 48.8% of the total effect (P < 0.01). CONCLUSIONS: Oral frailty was significantly associated with fall risk, and nutrition might be a mediating factor for adverse effects of oral frailty and fall risk. Enhancing the nutrition of older individuals is a vital approach to mitigating fall risk among those with oral frailty.

Comparative Transcriptome Analysis Explores the Mechanism of Angiosperm and Gymnosperm Deadwood Degradation by Fomes fomentarius.

In forest ecosystems, most of the soil organic matter is derived from trees, as deadwood lignocellulose and wood-decaying basidiomycetes are the most important decomposers of lignin and cellulose. Fomes fomentarius is one of the most common white-rot fungi colonizing angiosperm trees and is often found in birch deadwood but seldom in pine deadwood. To reveal the mechanism through which F. fomentarius selects angiosperms as its preferred host trees, birch and pinewood sticks were selected for culturing for two months. The weight loss, cellulose and lignin degradation rates, activities of degrading enzymes, and transcriptome analyses of two degradation models were compared and analyzed. The results showed that F. fomentarius-degraded birchwood with higher efficiency than pinewood. A GO enrichment analysis found that more upregulated genes related to the top 30 terms showed a molecular function related to degradation, and most genes belonged to the CAZymes family in F. fomentarius-degraded birchwood. However, pinewood degradation did not show these phenomena. A KEGG pathway analysis also indicated that, for the same pathway, more upregulated genes were involved in birchwood degradation caused by F. fomentarius than in pinewood degradation.

Explore Key Genes and Mechanisms Involved in Colon Cancer Progression Based on Bioinformatics Analysis.

To explore underlying mechanisms related to the progression of colon cancer and identify hub genes associated with the prognosis of patients with colon cancer. GSE10950 and GSE62932 were downloaded from the Gene Expression Omnibus (GEO) database. GEO2R was utilized to screen out the differentially expressed genes (DEGs). Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted on DEGs. Moreover, STRING and Cytoscape software were utilized for establishing the network of protein-protein interaction (PPI) and identifying hub genes. Afterward, data from The Cancer Genome Atlas (TCGA) was utilized for identifying prognosis-related hub genes by Kaplan-Meier survival analysis. Colon cancer cell line LOVO and human normal intestinal epithelial cell line NCM-460 were exploited to demonstrate the differential expression of selected hub genes through RT-qPCR and western blot. The LOVO cells were transfected to regulate expressions of prognosis-associated genes, followed by exploring the effects of those genes on prognosis by Cell Counting Kit-8 assay and colony-forming assay for cancer cell proliferation, cell scratch test and transwell migration assay for cancer cell migration and Annexin V-PE/7-AAD double staining as well as flow cytometry for cancer cell apoptosis. In this study, 266 common DEGs were obtained from the intersection of two datasets. The GO analysis suggested the common DEGs mainly participated in the one-carbon metabolic process, cell cycle G2/M phase transition, organelle fission, cell cycle phase transition regulation, and regulation of mitotic cell cycle phase transition. The KEGG analysis demonstrated the common DEGs were related to the p53 signaling pathway, nitrogen metabolism, mineral absorption, and cell cycle. 10 hub genes including CCNB1, KIF4A, TPX2, MT1F, PRC1, PLK4, CALD1, MMP9, CLCA1, and MMP1 were identified and CCNB1, CLCA1, and PLK4 were prognosis-related. Increased expression of CCNB1, CLCA1, and PLK4 restrained proliferation as well as migration of cancer cells and induced apoptosis of cancer cells. CCNB1, KIF4A, TPX2, MT1F, PRC1, PLK4, CALD1, MMP9, CLCA1, and MMP1 were identified as hub genes and CCNB1, CLCA1, and PLK4 could inhibit the progression of colon cancer through inhibiting proliferation as well as migration of the cancer cell and promoting apoptosis of cancer cell.

Whether biorefinery is a promising way to support waste source separation? From the life cycle perspective.

Since the implementation of the waste separation policy, the disposal of source-separated food waste (FW) has been more strictly required. Traditional source-separated FW treatment technologies, such as anaerobic digestion (AD) and aerobic composting (AC), suffer from low resource utilization efficiency and poor economic benefits. It is one of the main limiting factors for the promotion of waste separation. Life cycle assessment (LCA) was conducted for five municipal solid waste (MSW) treatment technologies, compared their environmental impacts, and analyzed the impact of waste separation ratios to determine whether biorefinery is a promising way to support waste source separation. The results showed that black soldier fly (BSF) treatment had the lowest net global warming potential (GWP) of all technologies, reduced by 40.8 % relative to the non-source-separated treatment. Ethanol production had the second-lowest net environmental impact potential because bioethanol replaces fossil fuel to avoid the emission of pollutants from its combustion. When two biorefinery technologies with excellent efficiency to avoid environmental impact are used to treat source-separated FW, the increase in the percentage of waste separation will help reduce the environmental impact of MSW treatment. The application of biorefinery technologies is considered a viable option for source-separated FW treatment. AC should not be widely promoted because it showed the worst net environmental benefits, and waste separation will elevate the environmental impact of its treatment process.

Secondary Metabolites from the Cultures of Medicinal Mushroom Vanderbylia robiniophila and Their Tyrosinase Inhibitory Activities.

Vanderbylia robiniophila (Huaier in Chinese) has been used as a traditional herbal medicine in China for over 1600 years. However, the secondary metabolites of V. robiniophila have not been systematically examined. Corresponding chemical investigation in this study led to the discovery of two new compounds, (22E, 24R)-6ß, 7α-dimethoxyergosta-8(14), 22-diene-3ß, 5α-diol (1) and vanderbyliolide A (8), along with eight known ones (2-7, 9-10). Their structures were determined by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. The tyrosinase inhibitory activity of all isolated compounds was evaluated, and compound 10 showed a potential tyrosinase inhibitory effect with an IC50 value of 60.47 ± 2.63 µM. Kinetic studies of the inhibition reactions suggested that 10 provides the inhibitory ability on tyrosinase in an uncompetitive way.

Molecular phylogeny and morphology reveal four new species of Thelephora (Thelephorales, Basidiomycota) from subtropical China, closely related to T. ganbajun.

The genus of Thelephora is a group of cosmopolitan ectomycorrhizal fungi with basidiocarps of morphological diversity that has an extremely scarce species reported from the forest ecosystem in China. In this study, phylogenetic analyses of Thelephora species from subtropical China were carried out based on multiple loci including the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), and the small subunit of mitochondrial rRNA gene (mtSSU). Maximum likelihood and Bayesian analyses were used to construct the phylogenetic tree. The phylogenetic positions of four new species, Th. aquila, Th. glaucoflora, Th. nebula, and Th. pseudoganbajun, were revealed based on morphological and molecular evidence. Molecular analyses demonstrated that the four new species were closely related to Th. ganbajun and formed a clade with robust support in the phylogenetic tree. Regarding morphology, they share some common morphological characteristics, including flabelliform to imbricate pilei, generative hyphae more or less covered by crystals, and subglobose to irregularly lobed basidiospores (5-8 × 4-7 µm) with tuberculate ornamentation. These new species are described and illustrated and are compared to similar morphological or phylogenetically related species. A key to the new and allied species from China is provided.

A Comparative Study of Three Nucleic Acid Integrity Assay Systems.

Background: The measurement of nucleic acid quality, especially the analysis of integrity, is a key step for many downstream experiments in biomedical research and quality control of biomaterials. General gel electrophoresis is a traditional method for nucleic acid integrity analysis. Currently, more electrophoresis techniques are becoming standardized and automated operations with higher precision. In this study, we have evaluated the comparability and bias of the outcomes from three commercial assay systems. Methods: Seventy-two deoxyribonucleic acid (DNA) and 67 ribonucleic acid (RNA) samples were selected for methodological comparison among different systems. The DNA Quality Number (DQN) and RNA Quality Number (RQN) of BIOptic Qsep400, DNA Quality Score (DQS) and RNA Quality Score (RQS) of PerkinElmer Labchip GX Touch HT were separately compared with the DNA Integrity Number (DIN) and RNA Integrity Number (RINe) of the Agilent 4200 TapeStation according to Clinical and Laboratory Standards Institute (CLSI) guideline (EP09-A3). Results: The biases of the mean estimated between DQN and DIN, DQS and DIN both exceeded the acceptance criteria. The Passing-Bablok regression analysis between DQN and DIN, and the Deming regression analysis between DQS and DIN, showed the biases were both within the acceptance criteria, and the bias between DQN and DIN was smaller. For the comparisons of RQN and RINe, RQS and RINe, the regression analyses revealed the biases were both within the acceptance criteria. The bias of the mean estimated between RQS and RINe was outside of the acceptance criteria. Conclusions: There was a good comparability in nucleic acid integrity detection between BIOptic Qsep400 and PerkinElmer Labchip GX Touch HT with the Agilent 4200 TapeStation. However, the bias and linear correlations require more attention between systems.

Construction on teaching quality evaluation indicator system of multi-disciplinary team (MDT) clinical nursing practice in China: A Delphi study.

AIM: To construct an evaluation indicator system for nursing multi-disciplinary team (MDT) clinical practice in China and to provide quantifiable indicators for MDT clinical teaching courses. METHODS: Based on relevant literature retrieval and analysis, a evaluation indicator system of nursing MDT clinical teaching quality was preliminarily constructed using the Donabedian. Structure-Process-Outcome model as theoretical guidance. Then, a final indicators content was formed after two rounds of expert consultation and Analytic Hierarchy Process (AHP) was used to determine the weight of indicators at all levels. RESULTS: The effective response rate of the questionnaires in two rounds were 95.23% (20/21) and 100% (20/20) respectively, the expert authority coefficient (Cr) were 0.838 and 0.853 respectively and the Kendall's coefficient of concordance (Kendall's W) of indicators at all levels were 0.137-0.612 (P < 0.05). The final evaluation index system consisted of three one-class indicators, 8 s-class indicators and 28 third-class indicators. CONCLUSION: The study constructed a comprehensive set of evaluation indicator system of nursing MDT clinical practice, which was scientific and reliable and provides reference for the clinical teaching quality evaluation of MDT nursing.

Study on degradation characteristics of imazamox by Streptomycetaceae.

The residues of imazamox (IMX) will cause phytotoxicity to subsequent crops after long-term use, and will also pollute the soil and its surrounding environment. This study isolates and identifies two strains of Streptomycetaceae JX02 and JX06 that can effectively degrade IMX. Use response surface method Box-Behnken design to optimize physicochemical parameters. The optimal degradation conditions of strains JX02 and JX06 are obtained and verified: IMX concentration is 150 mg L-1, the initial dosage is 9.9%, 9.1% (OD600 = 0.1), the temperature is 26.4 and 27.5 °C, and pH value is 7.0 and 7.7, respectively. The degradation rates of 150 mg L-1 IMX detected by HPLC within 4 d were 99 and 94%, respectively. After adding strains JX02 and JX06, the half-life of IMX in the soil is shortened to 11 d and 13 d, indicating that Streptomycetaceae had a positive effect on the remediation of soil. It is expected to provide scientific information for the rational use, environmental safety evaluation of IMX, and provide a basis for future research and development of microbial agents.

Hydnaceous fungi of China 8. Morphological and molecular identification of three new species of Sarcodon and a new record from southwest China.

Three new stipitate hydnoid fungi, Sarcodon coactus, S. grosselepidotus and S. lidongensis, are described and illustrated, based on morphological characteristics and nuc ITS rDNA + nuc LSU rDNA sequence analyses and a new record, S. leucopus, from China is reported. S. coactus is characterised by ellipsoid to round basidiocarps, reddish-brown to dark brown, felted pileal surface with white and incurved margins, simple-septate and partly short-celled generative hyphae and irregular subglobose, thin-walled, brown basidiospores with tuberculate ornamentation (tuberculi up to 1 µm long). S. grosselepidotus is characterised by infundibuliform to round, occasionally deeply fissured pileus, pale orange to dark ruby pileal surface with ascending and coarse scales, simple-septate generative hyphae and irregular ellipsoid to globose, thin-walled, brown basidiospores with tuberculate ornamentation (tuberculi up to 0.7 µm long). S. lidongensis is characterised by plano-convex to somewhat depressed and regular orbicular pileus, light brown to dark brown pileal surface with adhering squamose and purplish-brown, incurved and occasionally incised margin, cylindrical or broadened below stipe, simple-septate generative hyphae and irregular ellipsoid to subglobose, thin-walled basidiospores with tuberculate ornamentation (tuberculi up to 1 µm long). The absence of the clamp connection is the common morphological characteristic of these three new species; however, S. leucopus, a new record from China, has frequently clamped generative hyphae. Molecular analyses confirm the phylogenetic positions of three new and the new record species. The discriminating characters of these three new species and closely related species are discussed and a key to the species of Sarcodon from China is provided.

[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.

Efficacy of Pain Relief in Different Postherpetic Neuralgia Therapies: A Network Meta-Analysis.

BACKGROUND: Postherpetic neuralgia (PHN) is a nerve pain disease usually controlled by different therapies, i.e., topical therapies, antiepileptics, analgesics, antipsychotics, antidepressants, anti-dementia drugs, antivirals, amitriptyline, fluphenazine, and magnesium sulfate. It is believed that different therapies may lead to different levels of pain relief. OBJECTIVES: We proposed this study to compare the efficacy of PHN treatments. STUDY DESIGN: We conducted a systematic review of the current literature. All relevant studies were retrieved from online databases. The standardized mean difference (SMD) was used for pain relief measurement in different PHN therapies. SETTING: A conventional meta-analysis and a network meta-analysis (NMA) were carried out together with the surface under the cumulative ranking curve (SUCRA) for each therapy calculated regarding their efficacy. RESULTS: A pairwise meta-analysis suggested that 4 treatment classes, including topical therapies, antiepileptics, analgesics, and antidepressants, exhibited better pain relief results than placebo. Likewise, a NMA suggested that patients with 4 treatment classes exhibited significant improvements in pain scores compared to those with placebo. LIMITATIONS: There is a lack of direct head-to-head comparisons of some treatments, especially for antivirals, anti-dementia drugs, and magnesium sulfate. Secondly, the specific agents belonging to the same class of therapies might exhibit different effects (gabapentin and carisbamate) with different mechanisms (opioids and ketamine) on reducing pain, and some agents were hard to find in literatures and were not involved in our study, which may influence our results. CONCLUSIONS: Analgesics were preferable to other treatments with respect to pain relief for PHN, while antivirals appeared to be less effective than other therapies. KEY WORDS: Postherpetic neuralgia, topical agents, antiepileptics, analgesics, antipsychotics, antidepressants.

Coupling hybridization chain reaction with DNAzyme recycling for enzyme-free and dual amplified sensitive fluorescent detection of methyltransferase activity.

Aberrant DNA methylation originated from changes in DNA methyltransferase activity can lead to many genetic diseases and tumor types, and the monitoring of methyltransferase activity is thus of great importance in disease diagnosis and drug screening. In this work, by combing hybridization chain reaction (HCR) and metal ion-dependent DNAzyme recycling, we have developed a convenient enzyme-free signal amplification strategy for highly sensitive detection of DNA adenine methyltransferase (Dam MTase) activity and its inhibitors. The Dam MTase-induced methylation and subsequent cleavage of the methylated hairpin DNA probes by DpnI endonuclease lead to the release of ssDNA triggers for HCR formation of many Mg2+-dependent DNAzymes, in which the fluorescently quenched substrate sequences are catalytically and cyclically cleaved by Mg2+ to generate remarkably amplified fluorescent signals for highly sensitive detection of Dam MTase at 7.23 × 10-4 U/mL. In addition, the inhibition of different drugs to Dam MTase activity can also be evaluated with the developed method. With the advantages of simplicity and significant signal amplification over other common methods, the demonstrated biosensing approach thus offers great potential for highly sensitive detection of various methyltransferases and provides a convenient platform for drug screening for therapeutic applications.

Coupling hybridization chain reaction with catalytic hairpin assembly enables non-enzymatic and sensitive fluorescent detection of microRNA cancer biomarkers.

The identification and quantification of sequence-specific microRNAs (miRNAs) plays an important role in early diagnosis of different diseases. In this work, by integrating two independent signal amplification approaches, hybridization chain reaction and catalytic hairpin assembly, we report an enzyme-free and dual amplified approach for highly sensitive detection of a human prostate cancer biomarker, miR-141. The presence of miR-141 triggers the self-assembly of two hairpin DNAs into dsDNA polymers, which co-localize two split segments of ssDNA into proximity. Subsequently, these co-localized ssDNA sequences further act as triggers to initiate catalytic assembly of two fluorescently quenched hairpin DNAs to form numerous dsDNA strands, resulting in the recovery of the fluorescent emissions and remarkably amplified signals for highly sensitive detection of miR-141 down to 0.3 fM. In addition, this method is also selective for the target miRNA against other control sequences. With the advantages of high sensitivity and nanomaterial/enzyme-free detection format, the developed method can be a general sensing platform for the detection of trace amounts of sequence-specific nucleic acid targets.

Label-free and homogeneous aptamer proximity binding assay for fluorescent detection of protein biomarkers in human serum.

By using the aptamer proximity binding assay strategy, the development of a label-free and homogeneous approach for fluorescent detection of human platelet-derived growth factor BB (PDGF-BB) is described. Two G-quadruplex forming sequence-linked aptamers bind to the PDGF-BB proteins, which leads to the increase in local concentration of the aptamers and promotes the formation of the G-quadruplex structures. Subsequently, the fluorescent dye, N-methylmesoporphyrin IX, binds to these G-quadruplex structures and generates enhanced fluorescence emission signal for sensitive detection of PDGF-BB. The association of the aptamers to the PDGF-BB proteins is characterized by using native polyacrylamide gel electrophoresis. The experimental conditions are optimized to reach an estimated detection limit of 3.2nM for PDGF-BB. The developed method is also selective and can be applied for monitoring PDGF-BB in human serum samples. With the advantages of label-free and homogeneous detection, the demonstrated approach can be potentially employed to detect other biomarkers in a relatively simple way.

[Population difference of polypores in northwest and southeast of China].

Polypores are an important group of wood-rotting fungi and play a key role in decomposing wood in the forest ecosystem. Based on field investigations and laboratory analysis, fungal flora and diversity composition of polypores in Tianshan Moutains, Qilian Mountains, Baotianman Nature Reserve and Wuyi Mountains were analyzed. In total, 72 polypore species were found in Tianshan Mountains, 99 in Qilian Mountains, 124 in Baotianman Nature Reserve and 156 in Wuyi Mountains. There were fourteen common species in the four zones. The biogeography could be divided into 4 groups at genera level of the four zones, the important elements were North temperate element and cosmopolitan element, and floristic analysis showed a distinct north temperate character. The proportion of white rot polypores in the four zones increased from northwest to southeast of China, while the proportion of brown rot polypores decreased. Polypores preferentially grew on angiosperm trees compared to gymnosperm trees. Among the four zones, polypores in Baotianman had the highest proportion of species living on angiosperm trees. Rare and threatened species in Tianshan Mountains and Qilian Mountains were mainly found on conifer trees, while in the other two zones, most rare and threatened species were found on broadleaf trees. Generally, the distinctions of these four areas were mainly affected by the forest type.

[Effects of bortezomib combined with 5-azacytidine on the apoptosis of K562 cells and expression of SHIP mRNA].

This study was aimed to investigate the effects of bortezomib combined with 5-azacytidine on the apoptosis of K562 cells and expressiom of SHIP mRNA. The K562 cells were cultured and treated with different concentrations of bortezomib, 5-azacytidine or their combination for 24 hours. Then, the expression of SHIP mRNA was detected by RT-PCR,the cell proliferation was analyzed by using MTT assay and flow cytometry. The results showed that 5-20 nmol/L bortezomib could effectively inhibit the proliferation of K562 and this inhibitory effect gradually enhanced along with the increase of bortezomib concentration, the group of bortezomib combined with 5-azacytidine showed more inhibitory effect on K562 cells than that of bortezomib or 5-azacytidine alone.The bortezomib could promote the apoptosis of K562 cells in a dose-dependent manner,and this apoptotic effect was higher in group of bortezomib combined with 5-azacytidine than that in group of bortezomib or 5-azacytidine alone.Bortezomib could down-regulated the expression of SHIP mRNA in a dose-dependent manner,and this down-requlated effect was higher in group of bortezomib combined with 5-azacytidine than that in group of bortezomib or 5-azacytidine alone.It is concluded that bortezomib and 5-azacytidine can induce apoptosis by inhibiting the expression of SHIP mRNA in K562 cells.The combination of bortezomib with 5-azacytidine displays a synergetic effect.

Phylogenetic analysis of ligninolytic peroxidases: preliminary insights into the alternation of white-rot and brown-rot fungi in their lineage.

White-rot and brown-rot fungi employ different mechanisms to degrade lignocellulose. These fungi are not monophyletic and even alternate in their common lineage. To explore the reason for this, seventy-six ligninolytic peroxidases (LPs), including 14 sequences newly identified from available basidiomycetous whole-genome and EST databases in this study, were utilized for phylogenetic and selective pressure analyses. We demonstrate that LPs were subjected to the mixed process of concerted and birth-and-death evolution. After the duplication events of original LPs, various LP types may originate from mutation events of several key residues driven by positive selection, which may change LP types and even rot types in a small fraction of wood-decaying fungi. Our findings provide preliminary insights into the cause for the alternation of the two fungal rot types within the same lineage.

[Polypore diversity in main natural larch forests in China].

Larch is the important coniferous species in Northern China. Many polypore species are growing on the fallen trunks of natural larch forests, which can decompose the cellulose, semi cellulose, and lignin of the fallen trunks, and promote the matter cycling and maintain the carbon balance in forest ecosystem, playing a key ecological function in forest ecosystem. Aiming at the polypore species on the 5 main larch forest species in China, this paper analyzed the species composition and distribution characteristics of polypore, and compared the polypore species diversity on different kinds of larch in China. A total of 107 polypore species were recorded, belonging to 43 genera in 11 families, among which, brown fungi accounted for 45.4% of the total collected in this study, and occupied about 50% of the whole brown fungi reported in China. 91. 7% of the polypore grew on the decaying fallen trunk. Larix gmelini had more polypore species and individuals, as compared with the other 4 larch species. There was a high similarity in the polypore community composition on L. gmelini and L. olgensisi and on L. sibirica and L. griffithiana, which was in accordance with the natural distribution of related forests.

[Polypore species diversity, floral composition, and distribution characteristics in Changbai Mountains, Northeast China].

Polypore is an important group of wood-rotting fungi, which can decompose wood cellulose, semi-cellulose, and lignin into nutrients to be utilized by itself and other organisms, and accordingly, can promote the material cycling in forest ecosystem. Based on more than 10 years investigation and collection, it was found that the polypore in Changbai Mountains was rich in species diversity, with the Shannon diversity index being 5.06. In the Mountains, a total of 246 polypore species were recorded, occupying 40.7% of the total in China. The polypore species recorded belonged to 80 genera, 11 families, and 6 orders, among which, Polyporaceae was the dominant family. The most important bio-geographical elements of the polypore in Changbai Mountains were north temperate element and cosmopolitan element, other elements also included, showing a distinct north temperate character in floral composition. Pinus was the main host of polypore, supporting 41.5% of the polypore in Changbai Mountains. Most of the polypore was saprophytic, and its quantity had a significant correlation with the decaying degree of substrates, implying its important role in the material cycling in forest ecosystem in Changbai Mountains. There were 18 threatened polypore species in the Mountains, accounting for 37.5% of total in China. Besides their important ecological functions, many of the polypore also had higher economic value. On the premise of complete protection on them, these fungal resources should be exploited reasonably.