The association between genetic variants in lactotransferrin and dental caries: a meta- and gene-based analysis.

BACKGROUND: The pathogenesis of dental caries remains unclear, with increasing evidence suggesting that genetic susceptibility plays an essential role. Previous studies have reported the association between genetic polymorphisms in lactotransferrin (LTF) and the risk of dental caries with inconsistent results. METHODS: A systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases was performed by two authors independently for papers published before December 5, 2019 on the association between genetic variants in LTF and the risk of dental caries. We adopted the subsequent inclusion criteria to assess study eligibility: 1) The studies were based on human subjects; 2) the presence of dental caries should be screened for in both the case group and the control group; and 3) genotype data on variants in LTF were available in both the case group and the control group. We calculated odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) by using random-effects models to assess the association of genetic variants in LTF with the risk of dental caries. We also performed a gene-based analysis to explore the joint association of multiple genetic variants in LTF with the risk of dental caries. RESULTS: Our systematic literature search identified six relevant papers for analysis. We found no significant association between rs1126478 and the risk of dental caries when meta-analysing the genotype distribution between subjects with dental caries and those without dental caries (additive model: OR = 1.41; 95% CI = 0.98-2.02; P = 0.065). However, further analysis indicated that rs1126478 was associated with dental risk in subjects who had moderate or severe dental caries compared to those without dental caries (P < 0.0001). The gene-based analysis indicated that multiple genetic variants in LTF were jointly associated with the risk of dental caries (P = 0.002). CONCLUSIONS: The present meta-analysis revealed some evidence of the association between rs1126478 and dental caries and that multiple genetic variants in LTF are jointly associated with the risk of dental caries. Our findings need to be validated by larger studies that adjust for important confounding factors for the risk of dental caries.

Sodium fluoride induces apoptosis and autophagy via the endoplasmic reticulum stress pathway in MC3T3-E1 osteoblastic cells.

Fluorosis and bone pathologies can be caused by chronic and/or excessive fluoride intake. Despite this, few studies have been conducted on the cellular mechanisms underlying osteoblast toxicity in the presence of NaF. Here, we investigated the effects of fluoride on MC3T3-E1 cells. We showed that the proliferation of MC3T3-E1 cells was inhibited by exposure to NaF. In addition, apoptosis was induced by NaF, as caspase-associated proteins showed a higher level of expression and apoptotic bodies were formed. Furthermore, endoplasmic reticulum (ER) stress induced by NaF activated the unfolded protein response (UPR) and upregulated the expression of the glucose-regulated proteins 94 (GRP94) and 78 (BiP). Therefore, ER stress plays a vital role in NaF-induced autophagy and apoptosis. Furthermore, apoptosis is promoted following the inhibition of NaF-induced autophagy. In conclusion, under NaF treatment, the ER stress-signaling pathway is activated, leading to apoptosis and autophagy and affecting the proliferation and survival of MC3T3-E1 cells.

The first chromosome-level genome of the stag beetle Dorcus hopei Saunders, 1854 (Coleoptera: Lucanidae).

Stag beetles (Coleoptera: Lucanidae) represent a significant saproxylic assemblage in forest ecosystems and are noted for their enlarged mandibles and male polymorphism. Despite their relevance as ideal models for the study of exaggerated mandibles that aid in attracting mates, the regulatory mechanisms associated with these traits remain understudied, and restricted by the lack of high-quality reference genomes for stag beetles. To address this limitation, we successfully assembled the first chromosome-level genome of a representative species Dorcus hopei. The genome was 496.58 Mb in length, with a scaffold N50 size of 54.61 Mb, BUSCO values of 99.8%, and 96.8% of scaffolds anchored to nine pairs of chromosomes. We identified 285.27 Mb (57.45%) of repeat sequences and annotated 11,231 protein-coding genes. This genome will be a valuable resource for further understanding the evolution and ecology of stag beetles, and provides a basis for studying the mechanisms of exaggerated mandibles through comparative analysis.

Microplastic contamination in the dominant crabs at the intertidal zone of Chongming Island, Yangtze Estuary.

Crabs are one of the most critical and dominant species of the intertidal zone. Their feeding, burrowing, and other bioturbation activities are common and intense. However, baseline data on microplastic contamination in wild intertidal crabs are still lacking. In this study, we investigated the contamination of microplastics in the dominant crabs, Chiromantes dehaani, of the intertidal zone in Chongming Island, Yangtze Estuary, and explored their probable relationship with the microplastic composition in sediments. A total of 592 microplastic particles were observed in the crab tissues, with an abundance of 1.90 ± 0.53 items·g-1 (1.48 ± 0.45 items·ind-1). The microplastic contamination in the tissues of C. dehaani varied significantly among different sampling sites, organs, and size groups, but not among different sexes. Microplastics in C. dehaani were mainly rayon fibers with small sizes (<1000 µm). Their colors were mostly dark, which is consistent with the sediments samples. A linear regression showed significant correlations between the composition of microplastics in the crabs and that in sediments, although they differed in various crab organs and sediment layers. The target group index identified the feeding preference of C. dehaani on the microplastics with specific shapes, colors, sizes, and polymer types. In general, the microplastic contamination in crabs is affected by both objective environmental conditions and subjective feeding habits of crabs. In the future, more potential sources should be considered to completely distinguish the relationship between the microplastic contamination in crabs and adjacent environment.

Dual-crosslinked methacrylamide chitosan/poly(ε-caprolactone) nanofibers sequential releasing of tannic acid and curcumin drugs for accelerating wound healing.

The objective of this research study is to develop novel composite nanofibers based on methacrylamide chitosan (ChMA)/poly(ε-caprolactone) (PCL) materials by the dual crosslinking and coaxial-electrospinning strategies. The prepared ChMA/PCL composite nanofibers can sequentially deliver tannic acid and curcumin drugs to synergistically inhibit bacterial reproduction and accelerate wound healing. The rapid delivery of tannic acid is expected to inhibit pathogenic microorganisms and accelerate epithelialization in the early stage, while the slow and sustained release of curcumin is with the aim of relieving chronic inflammatory response and inducing dermal tissue maturation in the late stage. Meanwhile, dual-drugs sequentially released from the membrane exhibited a DPPH free radical scavenging rate of ca. 95 % and an antibacterial rate of above 85 %. Moreover, the membrane possessed great biocompatibility in vitro and significantly inhibited the release of pro-inflammatory factors (IL-1ß and TNF-α) in vivo. Animal experiments showed that the composite membrane by means of the synergistic effect of polyphenol drugs and ChMA nanofibers, could significantly alleviate macrophage infiltration and accelerate the healing process of wounds. From the above, the as-prepared ChMA-based membrane with a stage-wise release pattern of drugs could be a promising bioengineered construct for wound healing application.

Zinc ions and ciprofloxacin-encapsulated chitosan/poly(ɛ-caprolactone) composite nanofibers promote wound healing via enhanced antibacterial and immunomodulatory.

Antibacterial and anti-inflammatory nanofibrous membranes have attracted extensive attention, especially for the cutaneous wound treatment. In this study, zinc ions and ciprofloxacin-encapsulated chitosan/poly(ɛ-caprolactone) (CS/PCL) electrospun core-shell nanofibers were prepared by employing zinc ions-coordinated chitosan as the shell, and ciprofloxacin-functionalized PCL as the core. The morphology and core-shell structure of the as-prepared composite nanofibers were examined by SEM and TEM, respectively. The physical structure and mechanical property of the electrospun membrane were explored by FTIR, swelling, porosity and tensile test. Tensile strength of the zinc ions-coordinated CS/PCL composite nanofibers was enhanced to ca. 16 MPa. Meanwhile, the composite nanofibers can rapidly release of ciprofloxacin during 11 days and effectively suppress above 98 % of S. aureus proliferation. Moreover, the composite nanofibers exhibited excellent guide cell alignment and cyto-activity, as well as significantly down-regulated the inflammation factors, IL-6 and TNF-α in vitro. Animal experiments in vivo showed that the zinc ions-coordinated CS/PCL membrane by means of the synergistic effect of ciprofloxacin and active zinc ions, could significantly alleviate macrophage infiltration, promote collagen deposition and accelerate the healing process of wounds.

Cytotoxicity, endocrine disrupting activity, and chemical analysis of 42 food contact silicone rubber products.

After migration in 95 % ethanol (food simulant) at 70 °C for 2 h (accelerated conditions), the cytotoxicity and endocrine-disruption activity of 42 food contact silicone products (FCSPs) obtained from the Chinese market were studied. Of 31 kitchenwares, 96 % showed mild or above cytotoxicity (relative growth rate < 80 %) using the HeLa neutral red uptake test; and 84 % showed estrogenic (64 %), anti-estrogenic (19 %), androgenic (42 %), and anti-androgenic (39 %) activities by the Dual-luciferase reporter gene assay. The mold sample induced late phase HeLa apoptosis as detected by Annexin V-FITC/PI double staining flow cytometry, in addition, the migration of mold sample has a higher risk of endocrine disruption at high temperature usage. Encouragingly, 11 bottle nipples had neither cytotoxic nor hormonal activity. Utilizing multiple mass spectrometry techniques, non-intentionally added substances (NIASs) in 31 kitchenwares were analyzed, and the migration levels of 26 organic compounds and 21 metals were quantified, furthermore, the safe risk of single migrant was evaluated through their special migration limit (SML) or threshold of toxicological concern (TTC). Using "nchoosek" statement and Spearman's correlation analysis in MATLAB, the migration of 38 compounds or combinations including metals, plasticizers, methylsiloxanes, and lubricants, had strong correlation with cytotoxicity or hormonal activity. The coexistence of various chemical substances in migrants leads to complex biological toxicity of FCSPs, so it is very important to detect the toxicity of the final products. The combination of bioassays and chemical analyses are valuable tools to facilitate the identification and analyses of FCSPs and migrants that have potential safety risks.

Identification, migration, and childhood exposure of methylsiloxanes in silicone infant bottle nipples marketed in China.

The analysis, migration, and childhood exposure of methylsiloxanes (MSs) in 32 silicone infant bottle nipples marketed in China were studied. Thirty types of MSs in two families, which included 11 linear MSs (LMSs, L4-L14) and 19 cyclic MSs (CMSs, D4-D22), were identified using gas chromatography-mass spectrometry (GC-MS) associated with standards, retention index, and carbon number rule. In 32 nipples, MSs with molecular weight < 1000 Da and CMSs were predominant. Considering the actual daily use of bottle nipples, the migration tests of MSs from nipples to artificial saliva and reconstituted powdered formula were performed. In particular, the orthogonal test design-QuEChERS-GC/MS was employed to detect MSs in formula. The median migration level of ΣMSs (MW < 1000 Da) in formula was 950.9 ng/mL, which was much higher than that in artificial saliva (98.1 ng/mL). If formula is fed to children aged 3-36 months using bottle nipples according to product instructions, the daily oral exposure to ΣMSs (MW < 1000) for children ranged from 52 to 146 µg/kg bw-day, which were two to five orders of magnitude higher than those of other exposure pathways. In sum, oral intake (especially through formula) may be the predominant pathway of exposure of MSs in children. This research enhances our understanding of the oral exposure risks of MSs and provides useful information that could aid the development of risk management strategies.

Osteoinductive hybrid hydrogel membranes for in situ bone regeneration in hyperglycemia.

In hyperglycemia patients, suffering from insufficient vascularization and vascular network lesion, tissue regeneration, such as bone repair, is limited and maybe delayed by the secondary injury and hyperglycemic microenvironment. Typically, dental therapies involving guided bone regeneration is facing a difficult condition in the patients with diabetes. In this study, a hybrid membrane was endowed with biomimetic function to create an angiogenesis-inductive microenvironment by calcium ion release to overcome the limitations of bone tissue regeneration in diabetic patients. Biomineralized calcium resource was Janus-structured onto the surface of hybrid hydrogel by layer-by-layer technique to enhance vascularization and improve the bone regeneration in this study. The release of calcium ions from mineralized phases was controlled by the solubility of inorganic phases and the degradation of gels, promoting HIF-1α expression and creating a key role in angiogenesis stimulation. With highly enhanced calcium signaling and blood vessel formation, the hybrid hydrogel membranes improved the recruitment, proliferation and differentiation of mesenchymal stem cells and endothelial progenitors, confirmed by the enhancement of microvascular regeneration and new bone formation in the critical-sized calvarial defect in diabetic model in vivo. Our study demonstrates a translational potential of hybrid hydrogels engineered with inorganic minerals for orthopedic applications in hyperglycemia.

Optimizing the chitosan-PCL based membranes with random/aligned fiber structure for controlled ciprofloxacin delivery and wound healing.

The aim of this study was to optimize the chitosan/polycaprolactone (CS/PCL) electrospun nanofibrous membrane with random/aligned fiber structures to provide a controlled release of ciprofloxacin (Cip) and guide skin fibroblasts arrangement. A series of Cip-encapsulated CS/PCL electrospun membranes were prepared by coaxial-electrospinning. The existence of Cip in core-shell structured fibers was confirmed by using SEM, TEM and FTIR characterizations. The in vitro drug-release profiles suggested that the Cip presented a sustained release for 15 days. Simultaneously, cyto-compatibility of the membranes decreased with the increasing amount of Cip from 2.0% to 5.0%. In particular, aligned CS/PCL membrane loading with 2.0% Cip exhibited a good balanced ability between cell proliferation and antibacterial effect (>99% against Escherichia coli and Staphylococcus aureus), which significantly accelerated the wound healing process in vivo. These results suggested that the aligned CS/PCL membrane loading with 2.0% Cip exhibited great antibacterial property and biocompatibility, which possess promising applications potential for wound healing.

Powdered activated carbon doping improves the mechanical and adsorption properties of cementitious microfiltration membrane.

Cementitious membrane (CM) is a promising microfiltration membrane with low cost for raw materials and low energy consumption of non-sintering fabrication process. A novel carbon-cementitious microfiltration membrane (CCM) was fabricated with powdered activated carbon (PAC) as an additive based on CM, to solve the low mechanical strength of CM during multiple practical uses. While maintaining adequate pure water flux and porosity, the mechanical strength of the membrane was greatly improved to ensure the stability of the membrane in the filtration process. The bending strength of the CCM was 2-3 times higher than that of CM. 10 wt% CCM has the smallest critical pore size and optimal permeability, which was chosen to be the optimal PAC doping ratio. The X-ray diffraction and FT-IR results indicated that the addition of PAC did not change the mineral composition of cement hydration products, and the appropriate amount of PAC acted as a nucleation site and accelerated hydration. The effect of size effect on bending strength was more obvious with the decrease of membrane thickness. In the membrane adsorption experiments of benzophenone-4, nitrobenzene and p-chloronitrobenzene, the CCM exhibited prominent adsorption properties than CM. These results broaden the application scope of microfiltration membranes in water treatment process.

Electroless deposition of copper nanoparticles integrates polydopamine coating on reverse osmosis membranes for efficient biofouling mitigation.

In this study, highly antimicrobial CuNPs were integrated into a hydrophilic polydopamine (PDA) coating and immobilized on a RO TFC membrane via a mild and facile reduction approach to form a stable and durable dual-functional layer. Based on the XDLVO analysis, the introduction of PDA increased the membrane-foulant total interaction energy (ΔGmwf) to 14.13 mJ/m2, resulting in improved anti-adhesive properties as demonstrated by a 37% decrease in BSA adsorption for the modified membranes. The well dispersed and high loadings of CuNPs induced by PDA conferred strong bacterial toxicity to the modified membranes, reducing the viability of E. coli by 76%. Furthermore, the presence of catechol groups on PDA favors the formation of covalent bond with CuNPs, thus prolonging the durability of the copper-based anti-biofouling membranes. The combination of PDA coating and CuNPs functionalization imparts the membrane with simultaneous anti-adhesive and anti-microbial properties, leading to a substantial reduction in biofouling propensity in dynamic biofouling experiments. Specifically, the flux decline due to biofouling observed for the modified membranes significantly decreased from 65% to 39%, and biofilm thickness and TOC biomass were 58%, and 55% lower, respectively. This study provides a facile and versatile strategy to construct high performance RO membranes with excellent anti-biofouling functionality.

Association of genetic variants in enamel-formation genes with dental caries: A meta- and gene-cluster analysis.

Previous studies have reported the association between multiple genetic variants in the enamel-formation genes and the risk of dental caries with inconsistent results. We performed a systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases for studies published before March 21, 2020 and conducted meta-, gene-based and gene-cluster analysis on the association between genetic variants in the enamel-formation genes and the risk of dental caries. We identified 21 relevant publications including a total of 24 studies for analysis. The genetic variant rs17878486 in AMELX was significantly associated with dental caries risk (OR = 1.40, 95% CI: 1.02-1.93, P = 0.037). We found no significant association between the risk of dental caries with rs12640848 in ENAM (OR = 1.15, 95% CI: 0.88-1.52, P = 0.310), rs1784418 in MMP20 (OR = 1.07, 95% CI: 0.76-1.49, P = 0.702) and rs3796704 in ENAM (OR = 1.06, 95% CI: 0.96-1.17, P = 0.228). Gene-based analysis indicated that multiple genetic variants in AMELX showed joint association with the risk of dental caries (6 variants; P < 10-5), so did genetic variants in MMP13 (3 variants; P = 0.004), MMP2 (3 variants; P < 10-5), MMP20 (2 variants; P < 10-5) and MMP3 (2 variants; P < 10-5). The gene-cluster analysis indicated a significant association between the genetic variants in this enamel-formation gene cluster and the risk of dental caries (P < 10-5). The present meta-analysis revealed that genetic variant rs17878486 in AMELX was associated with dental caries, and multiple genetic variants in the enamel-formation genes jointly contributed to the risk of dental caries, supporting the role of genetic variants in the enamel-formation genes in the etiology of dental caries.

A boronic acid carbon nanodots/poly(thionine) sensing platform for the accurate and reliable detection of NADH.

In this work, a novel electrochemical sensing platform was designed and fabricated by the modification of boronic acid functionalized carbon nanodots (B-CNDs) and poly(thionine) (pTHI) on an electrode surface. B-CNDs can not only accelerate electron transfer but also covalently interact with cis-diol groups of dihydronicotinamide adenine dinucleotide (NADH) through functionalized boronic acid groups. Meanwhile, pTHI served as an inner reference element to provide a built-in correction, which enabled the sensor to detect NADH with high accuracy and reliability based on a ratiometric signal (∆INADH/∆ITHI). The electrochemical experimental results demonstrated that the ratiometric strategy-based sensor possessed good selectivity and high sensitivity. A linear range of 5.0 × 10-7 - 2.0 × 10-4 mol/L for NADH detection was obtained with a limit of detection of 1.5 × 10-7 mol/L. The sensor has been applied to analyze NADH in human serum samples with satisfactory results. The simple and effective ratiometric strategy reported here can be further used to prepare electrochemical sensors for selective, sensitive, and reliable detection of other cis-diol compounds.

Chromosome-level assembly of the mustache toad genome using third-generation DNA sequencing and Hi-C analysis.

BACKGROUND: The mustache toad, Vibrissaphora ailaonica, is endemic to China and belongs to the Megophryidae family. Like other mustache toad species, V. ailaonica males temporarily develop keratinized nuptial spines on their upper jaw during each breeding season, which fall off at the end of the breeding season. This feature is likely result of the reversal of sexual dimorphism in body size, with males being larger than females. A high-quality reference genome for the mustache toad would be invaluable to investigate the genetic mechanism underlying these repeatedly developing keratinized spines. FINDINGS: To construct the mustache toad genome, we generated 225 Gb of short reads and 277 Gb of long reads using Illumina and Pacific Biosciences (PacBio) sequencing technologies, respectively. Sequencing data were assembled into a 3.53-Gb genome assembly, with a contig N50 length of 821 kb. We also used high-throughput chromosome conformation capture (Hi-C) technology to identify contacts between contigs, then assembled contigs into scaffolds and assembled a genome with 13 chromosomes and a scaffold N50 length of 412.42 Mb. Based on the 26,227 protein-coding genes annotated in the genome, we analyzed phylogenetic relationships between the mustache toad and other chordate species. The mustache toad has a relatively higher evolutionary rate and separated from a common ancestor of the marine toad, bullfrog, and Tibetan frog 206.1 million years ago. Furthermore, we identified 201 expanded gene families in the mustache toad, which were mainly enriched in immune pathway, keratin filament, and metabolic processes. CONCLUSIONS: Using Illumina, PacBio, and Hi-C technologies, we constructed the first high-quality chromosome-level mustache toad genome. This work not only offers a valuable reference genome for functional studies of mustache toad traits but also provides important chromosomal information for wider genome comparisons.

"Sign-on/off" sensing interface design and fabrication for propyl gallate recognition and sensitive detection.

A new strategy based on sign-on and sign-off was proposed for propyl gallate (PG) determination by an electrochemical sensor. The successively modified poly(thionine) (PTH) and molecular imprinted polymer (MIP) showed an obvious electrocatalysis and a good recognition toward PG, respectively. Furthermore, the rebound PG molecules in imprinted cavities not only were oxidized but also blocked the electron transmission channels for PTH redox. Thus, a sign-on from PG current and a sign-off from PTH current were combined as a dual-sign for PG detection. Meanwhile, the modified MIP endowed the sensor with recognition capacity. The electrochemical experimental results demonstrated that the prepared sensor possessed good selectivity and high sensitivity. A linear ranging from 5.0×10(-8) to 1.0×10(-4)mol/L for PG detection was obtained with a limit of detection of 2.4×10(-8)mol/L. And the sensor has been applied to analyze PG in real samples with satisfactory results. The simple, low cost, and effective strategy reported here can be further used to prepare electrochemical sensors for other compounds selective recognition and sensitive detection.

[Stability of the anterior teeth and hard tissue of skeletal class III malocclusion after orthodontic surgery: systematic review].

OBJECTIVE: This study aims to analyze the long-term stability of the anterior teeth and hard tissue of skeletal class III malocclusion after a three-year orthodontic surgery by systematic review. METHODS: All studies about skeletal class III malocclusion with orthodontic-surgery were searched by computer-based retrieval and manual retrieval; the deadline is December 2013. The literature, filtered according to the inclusion criteria and exclusion criteria, was performed with quality. assessment. The same indicators of the anterior location and hard tissue stability were combined and evaluated with metaanalysis and descriptive analysis by Rev Man5.2. RESULTS: Four before-and-after comparison study articles with 180 cases were included. The grades of the four literature evaluation were A. The meta-analysis results showed that comparing the three-year post-orthodontic-surgery and post-orthodontic-surgery, the total weighted mean difference (WMD) of Ul-SN was 4.29 (P<0.05); the WMD of Ll-MP, OB, OJ, SNA, SNB, ANB, and MP-SN were -1.58, 0, -0.41, -0.58, 0.25, -0.70, and 0.39, respectively (P>0.05). The measurement methods of A and B point position were different, hence the qualitative description were as follows: point A remained at a relatively stable position, and point B had some replacement compared with post-operative (P<0.05). CONCLUSION: To the skeletal class III malocclusion after three-year orthodontic-surgery, the position of the lower anterior teeth could be kept stable, as well as the overbite and the overjet of the anterior teeth; only the upper inci- sor has a lip-inclined relapse. The maxillary could also be kept stable, and the mandibular had a little relapse.

[Application research of cone beam CT in dowel preparation for the mandibular first molar].

OBJECTIVE: To measure the root anatomic topography of mandibular first molar using cone beam CT (CBCT), calculate the proper space for dowel preparation. METHODS: The roots of 121 mandibular first molars from 71 patients were scanned by CBCT, the images from cross section, sagittal plane, and coronal plane were got respectively. The dowel preparation spaces according to established three dimensional images and dowel preparation requirements were analyzed. RESULTS: Three dowels could be prepared. The dowel length for distal-root was (7.19 +/- 0.91) mm, dowel diameter was (0.80 +/- 0.12) mm on the level of 4mm above root apex. The dowel length for mesio-root was (6.92 +/- 1.02) mm, and dowel diameter was (0.71 +/- 0.08) mm on the lever of 4 mm above root apex for buccal side and (0.71 +/- 0.07) mm for lingual side. Dowel should be prepared cone-shaped. CONCLUSION: Many factors affect dowel preparation, individualized design is needed. CBCT can provide reliable radiographic evidence.

Modeling and mechanism of the adsorption of copper ion onto natural bamboo sawdust.

The sorption of copper ions onto natural bamboo sawdust with cellulose-lignin polymeric structure strongly depends on pH. The adsorption capacity for copper ions increases as increasing pH and copper loadings. The fitting of copper pH boundary curve by NEM surface complexation models shows that: three-sites model including the ion exchange reaction of permanent charge fits better than two-sites model. The incorporation of the hydrated ion reaction gives better fitting results. XAFS study shows that: copper ions mainly form inner complexation with sawdust, but there is no obvious evidence on the complexation of carboxylic acid groups with copper ions. EXAFS fitting result shows that: as pH rises, the spatial configuration of copper ions shifts from tetrahedron to octahedron. Meanwhile the increase in the coordination number indicates that hydrated copper ions participate in the adsorption. Both XANES and EXFAS spectrum offer a similar explanation for copper adsorption in the range of experimental and fitting errors.