Kaempferol protects gut-vascular barrier from high glucose-induced disorder via NF-κB pathway.

Kaempferol is a natural edible flavonoid reported to treat high-fat diet-induced intestinal inflammation; however, the underlying molecular mechanisms remain unclear. This research aims to investigate the protective effect of kaempferol on the gut-vascular barrier (GVB) induced by high glucose and elucidate the underlying mechanism. Evans blue albumin efflux assay was used to test endothelial cell permeability. The results showed that kaempferol (50 µM) significantly reversed the high glucose-induced monolayer barrier permeability of rat intestinal microvascular endothelial cells (RIMVECs), while kaempferol significantly alleviated the high glucose-induced rarefication of the tight junction protein Claudin-5. Moreover, kaempferol also reduced high glucose-induced angiogenesis and cell migration via inhibiting the VEGFR2/p38 pathway. Kaempferol also protected against high glucose-induced overproduction of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 by inhibiting NF-κB p65 nuclear translocation. In addition, kaempferol had similar effects to the NF-κB inhibitor SN50 in reducing high glucose-induced ICAM-1 expression and endothelial barrier permeabilization. Our findings in part reveal the pathological mechanism of hyperglycemia-related gastrointestinal diseases and underlie the molecular mechanism of kaempferol in inhibiting bowel inflammation from a novel perspective.

Cell volume controlled by LRRC8A-formed volume-regulated anion channels fine-tunes T cell activation and function.

Biosynthesis drives the cell volume increase during T cell activation. However, the contribution of cell volume regulation in TCR signaling during T lymphoblast formation and its underlying mechanisms remain unclear. Here we show that cell volume regulation is required for optimal T cell activation. Inhibition of VRACs (volume-regulated anion channels) and deletion of leucine-rich repeat-containing protein 8A (LRRC8A) channel components impair T cell activation and function, particularly under weak TCR stimulation. Additionally, LRRC8A has distinct influences on mRNA transcriptional profiles, indicating the prominent effects of cell volume regulation for T cell functions. Moreover, cell volume regulation via LRRC8A controls T cell-mediated antiviral immunity and shapes the TCR repertoire in the thymus. Mechanistically, LRRC8A governs stringent cell volume increase via regulated volume decrease (RVD) during T cell blast formation to keep the TCR signaling molecules at an adequate density. Together, our results show a further layer of T cell activation regulation that LRRC8A functions as a cell volume controlling "valve" to facilitate T cell activation.

Autophagy/ferroptosis in colorectal cancer: Carcinogenic view and nanoparticle-mediated cell death regulation.

The cell death mechanisms have a long history of being evaluated in diseases and pathological events. The ability of triggering cell death is considered to be a promising strategy in cancer therapy, but some mechanisms have dual functions in cancer, requiring more elucidation of underlying factors. Colorectal cancer (CRC) is a disease and malignant condition of colon and rectal that causes high mortality and morbidity. The autophagy targeting in CRC is therapeutic importance and this cell death mechanism can interact with apoptosis in inhibiting or increasing apoptosis. Autophagy has interaction with ferroptosis as another cell death pathway in CRC and can accelerate ferroptosis in suppressing growth and invasion. The dysregulation of autophagy affects the drug resistance in CRC and pro-survival autophagy can induce drug resistance. Therefore, inhibition of protective autophagy enhances chemosensitivity in CRC cells. Moreover, autophagy displays interaction with metastasis and EMT as a potent regulator of invasion in CRC cells. The same is true for ferroptosis, but the difference is that function of ferroptosis is determined and it can reduce viability. The lack of ferroptosis can cause development of chemoresistance in CRC cells and this cell death mechanism is regulated by various pathways and mechanisms that autophagy is among them. Therefore, current review paper provides a state-of-art analysis of autophagy, ferroptosis and their crosstalk in CRC. The nanoparticle-mediated regulation of cell death mechanisms in CRC causes changes in progression. The stimulation of ferroptosis and control of autophagy (induction or inhibition) by nanoparticles can impair CRC progression. The engineering part of nanoparticle synthesis to control autophagy and ferroptosis in CRC still requires more attention.

Escin ameliorates inflammation via inhibiting mechanical stretch and chemically induced Piezo1 activation in vascular endothelial cells.

Escin is an active ingredient used in the treatment of phlebitis. However, the pharmacological mechanism of escin remains largely unclear. Here, we aimed to determine the molecular basis for the therapeutic effect of escin. Human umbilical vein endothelial cells (HUVECs) were subjected to shear-stress assays with or without escin. Intracellular Ca2+ levels, inflammatory factors and the activity of NF-κB were measured in endothelial cells (ECs) after mechanical-stretch or Yoda1 activation. Isometric tensions in aortic rings were identified. In addition, murine liver endothelial cells (MLECs) isolated from Piezo1 endothelial specific knockout mice (Piezo1△ EC) were used to explore the role of Piezo1. Our results showed that escin inhibited inflammatory factors, intracellular Ca2+ levels and Yoda1-evoked relaxation of thoracic aorta rings. Cell alignment induced by shear stress was inhibited by escin in HUVECs, and Piezo1 siRNA was used to show that this effect was dependent on Piezo1 channels. Moreover, escin reduced the inflammation and inhibited the activity of NF-κB in ECs with mechanical-stretch, which were insensitive to Piezo1 deletion. SN50, an NF-κB antagonist, significantly inhibited the mechanical stretch-induced inflammatory response. In addition, escin reduced inflammation in ECs subjected to mechanical-stretch, which was insensitive after using NF-κB antagonist. Collectively, our results demonstrate that escin inhibits the mechanical stretch-induced inflammatory response via a Piezo1-mediated NF-κB pathway. This study improves our understanding of a molecular target of escin that mediates its effect on chronic vascular inflammation.

[Evaluation of the clinical effect of acupuncture in treatment of neck pain in cervical spondylosis based on propensity score matching].

OBJECTIVE: To observe the clinical effect and safety of acupuncture in treatment of neck pain due to cervical spondylosis. METHODS: According to the patients' preference and acceptance for the interventions of neck pain induced by cervical spondylosis, an acupuncture group (221 cases) and a non-acupuncture group (251 cases) were divided. After the control of confounding factors with propensity score matching, 218 cases were included in either acupuncture group or non-acupuncture group. In the acupuncture group, acupuncture was applied to Dazhui (GV 14), Baihui (GV 20), ashi points, bilateral neck-Jiaji (EX-B 2), Fengchi (GB 20), Houxi (SI 3), Shenmai (BL 62), etc. The treatment was given once daily, one course of intervention was composed of 5 treatments and 3 courses were included. In the non-acupuncture group, the oral administration of imrecoxib tablets and cobalt tablets was prescribed for 2 weeks. Before and after treatment, the scores of Northwick Park questionnaire (NPQ) and the simplified McGill pain questionnaire (SF-MPQ) were observed, and the safety was assessed in patients of the two groups. RESULTS: After treatment completion, the scores of NPQ and SF-MPQ were all reduced when compared with those before treatment in each group (P<0.001), and the scores of NPQ and SF-MPQ in the acupuncture group were lower than those of the non-acupuncture group (P<0.001). The incidence of adverse reactions was 6.0% (13/218) in the acupuncture group and was 10.1% (22/218) in the non-acupuncture group, without statistical significance in comparison (P>0.05). CONCLUSION: Acupuncture is effective and safe in the relief of neck pain and the improvement of comprehensive quality of life in the patients with cervical spondylosis.

Foliar Fertilizer Application Alters the Effect of Girdling on the Nutrient Contents and Yield of Camellia oleifera.

Improving the economic benefits of Camellia oleifera is a major problem for C. oleifera growers, and girdling and foliar fertilizer have significant effects on improving the economic benefits of plants. This study explains the effects of girdling, girdling + foliar fertilizer on nutrient distribution, and the economic benefits of C. oleifera at different times. It also explains the N, P, and K contents of roots, leaves, fruits, and flower buds (sampled in March, May, August, and October 2021) and their economic benefits. The results showed girdling promoted the accumulation of N and K in leaves in March 2021 (before spring shoot emergence) but inhibited the accumulation of P, which led to the accumulation of P in roots and that of N in fruits in August 2021 (fruit expansion period). Foliar fertilizer application after girdling replenished the P content of leaves in March 2021, and P continued to accumulate in large quantities at the subsequent sampling time points. The N and P contents of the root system decreased in March. In October (fruit ripening stage), girdled shrubs showed higher contents of N and K in fruits and flower buds, and consequently lower relative contents of N and K in roots and leaves but higher content of P in leaves. Foliar fertilizer application slowed down the effects of girdling on nutrient accumulation in fruits and flower buds. Spraying foliar fertilizer decreased the N:P ratio in the flower buds and fruits of girdled plants. Thus, foliar fertilizer spray weakened the effects of girdling on the nutrient content and economic benefits of C. oleifera. In conclusion, girdling changed the nutrient accumulation pattern in various organs of C. oleifera at different stages, increased leaf N:K ratio before shoot emergence, reduced root K content at the fruit expansion stage and the N:K ratio of mature fruit, and promoted economic benefits.

Effect of dedifferentiation on noise propagation in cellular hierarchy.

Many fast renewing tissues have a hierarchical structure. Tissue-specific stem cells are at the root of this cellular hierarchy, which give rive to a whole range of specialized cells via cellular differentiation. However, increasing evidence shows that the hierarchical structure can be broken due to cellular dedifferentiation in which cells at differentiated stages can revert to the stem cell stage. Dedifferentiation has significant impacts on many aspects of hierarchical tissues. Here we investigate the effect of dedifferentiation on noise propagation by developing a stochastic model composed of different cell types. The moment equations are derived, via which we systematically investigate how the noise in the cell number is changed by dedifferentiation. Our results suggest that dedifferentiation have different effects on the noises in the numbers of stem cells and nonstem cells. Specifically, the noise in the number of stem cells is significantly reduced by increasing dedifferentiation probability. Due to the dual effect of dedifferentiation on nonstem cells, however, more complex changes could happen to the noise in the number of nonstem cells by increasing dedifferentiation probability. Furthermore, it is found that even though dedifferentiation could turn part of the noise propagation process into a noise-amplifying step, it is very unlikely to turn the entire process into a noise-amplifying cascade.

Inhibition of chemically and mechanically activated Piezo1 channels as a mechanism for ameliorating atherosclerosis with salvianolic acid B.

BACKGROUND AND PURPOSE: Salvianolic acid B (SalB) is effective for treating cardiovascular diseases. However, the molecular mechanisms underlying its therapeutic effects remain unclear. Mechanosensitive Piezo1 channels play important roles in vascular biology, although their pharmacological properties are poorly defined. Here, we aimed to identify novel Piezo1 inhibitors and gain insights into their mechanisms of action. EXPERIMENTAL APPROACH: Intracellular Ca2+ ions were measured in HUVECs, murine liver endothelial cells (MLECs), THP-1 and RAW264.7 cell lines and bone marrow-derived macrophages (BMDMs). Isometric tensions in mouse thoracic aorta were recorded. Shear-stress assays with HUVECs were conducted. Patch-clamp recordings with mechanical stimulation were performed with HUVECs in whole-cell mode. Foam cell formation was induced by treating BMDMs with oxidised LDL (oxLDL). Atherosclerotic plaque assays were performed with Ldlr-/- and Piezo1 genetically depleted mice on a high-fat diet. KEY RESULTS: Salvianolic acid B inhibited Yoda1-induced Ca2+ influx in HUVECs and MLECs. Similar results were observed in macrophage cell lines and BMDMs. Furthermore, we demonstrated that salvianolic acid B inhibited Yoda1- and mechanically activated currents. Salvianolic acid B suppressed Yoda1-induced aortic ring relaxation and inhibited HUVECs alignment in the direction of shear stress. Additionally, Yoda1 enhanced the formation of foam cells, which was reversed by salvianolic acid B. Salvianolic acid B also inhibited formation of atherosclerotic plaques and was insensitive to Piezo1 genetic depletion. CONCLUSION AND IMPLICATIONS: Our study provides novel mechanistic insights into the inhibitory role of salvianolic acid B against Piezo1 channels and improves our understanding of salvianolic acid B in preventing atherosclerotic lesions.

The role of angiogenesis in melanoma: Clinical treatments and future expectations.

The incidence of melanoma has increased rapidly over the past few decades, with mortality accounting for more than 75% of all skin cancers. The high metastatic potential of Melanoma is an essential factor in its high mortality. Vascular angiogenic system has been proved to be crucial for the metastasis of melanoma. An in-depth understanding of angiogenesis will be of great benefit to melanoma treatment and may promote the development of melanoma therapies. This review summarizes the recent advances and challenges of anti-angiogenic agents, including monoclonal antibodies, tyrosine kinase inhibitors, human recombinant Endostatin, and traditional Chinese herbal medicine. We hope to provide a better understanding of the mechanisms, clinical research progress, and future research directions of melanoma.

Bi/BiVO4/NiFe-LDH heterostructures with enhanced photoelectrochemical performance for streptomycin detection.

Streptomycin (STR) plays an essential role in bacterial infection treatments. Selectivity and sensitivity of photoelectrochemical (PEC) sensors are the two most important parameters, which can be measured using the photosensitivity of its active material. We prepared a novel PEC sensor to detect STR using Bi/BiVO4/LDH (layered double hydroxides) heterostructures as an active material, which is photoactive in the visible light wavelength range. The simultaneous presence of LDH and Bi/BiVO4 enhanced the material photocurrent response, which was linear to the STR concentrations in the 0.01-500 nmol/L range. The STR detection limit by this sensor was 0.0042 nmol/L. Our novel PEC-based sensing strategy includes using an ultra-sensitive and highly selective sensor for STR detection. Additionally, the two-pot synthesis of Bi/BiVO4/LDH developed in this work is environmentally friendly.

The Design of the Emission Layer for Electron Multipliers.

The electron multipliers gain is closely related to the secondary electron emission coefficient (SEE) of the emission layer materials. The SEE is closely related to the thickness of the emission layer. If the emission layer is thin, the low SEE causes the low gain of electron multipliers. If the emission layer is thick, the conductive layer can't timely supplement charge to the emission layer, the electronic amplifier gain is low too. The electron multipliers usually choose Al2O3 and MgO film as the emission layer because of the high SEE level. MgO easy deliquescence into Mg(OH)2 Mg2(OH)2CO3 and MgCO3 resulting in the lower SEE level. The SEE level of Al2O3 is lower than MgO, but Al2O3 is stable. We designed a spherical system for testing the SEE level of materials, and proposed to use low-energy secondary electrons instead of low-energy electron beam for neutralization to measuring the SEE level of Al2O3, MgO, MgO/Al2O3, Al2O3/MgO, and precisely control the film thickness by using atomic layer deposition. We propose to compare the SEE under the adjacent incident electrons energy to partition the SEE value of the material, and obtain four empirical formulas for the relationship between SEE and thickness. Since the main materials that cause the decrease in SEE are Mg2(OH)2CO3 and MgCO3, we use the C element atomic concentration measured by XPS to study the deliquescent depth of the material. We propose to use the concept of transition layer for SEE interpretation of multilayer materials. Through experiments and calculations, we put forward a new emission layer for electron multipliers, including 2-3 nm Al2O3 buffer layer, 5-9 nm MgO main-body layer, 1 nm Al2O3 protective layer or 0.3 nm Al2O3 enhancement layer. We prepared this emission layer to microchannel plate (MCP), which significantly improved the gain of MCP. We can also apply this new emission layer to channel electron multiplier and separate electron multiplier.

The Design of the AZO Conductive Layer on Microchannel Plate.

When the resistivity of the AZO conductive layer is within the MCP resistance requirement, the interval of the Zn content is very narrow (70-73%) and difficult to control. Aiming at the characteristics of the AZO conductive layer on the microchannel plate, an algorithm is designed to adjust the ratio of the conductive material ZnO and the high resistance material Al2O3. We put forward the concept of the working resistance of the MCP (i.e., the resistance during the electron avalanche in the microchannel). The working resistance of AZO-ALD-MCP (Al2O3/ZnO atomic layer deposition microchannel plate) was measured for the first time by the MCP resistance test system. In comparison with the conventional MCP, we found that the resistance of AZO-ALD-MCP in working state and non-working state is very different, and as the voltage increases, the working resistance significantly decreases. Therefore, we proposed a set of analytical methods for the conductive layer. We also proposed to adjust the ratio of the conductive material of the ALD-MCP conductive layer to the high-resistance material under the working resistance condition, and successfully prepared high-gain AZO-ALD-MCP. This design opens the way for finding better materials for the conductive layer of ALD-MCP to improve the performance of MCP.

Stochastic stem cell models with mutation: A comparison of asymmetric and symmetric divisions.

In order to fulfill cell proliferation and differentiation through cellular hierarchy, stem cells can undergo either asymmetric or symmetric divisions. Recent studies pay special attention to the effect of different modes of stem cell division on the lifetime risk of cancer, and report that symmetric division is more beneficial to delay the onset of cancer. The fate uncertainty of symmetric division is considered to be the reason for the cancer-delaying effect. In this paper we compare asymmetric and symmetric divisions of stem cells via studying stochastic stem cell models with mutation. Specially, by using rigorous mathematical analysis we find that both the asymmetric and symmetric models show the same statistical average, but the symmetric model shows higher fluctuation than the asymmetric model. We further show that the difference between the two models would be more remarkable for lower mutation rates. Our work quantifies the uncertainty of cell division and highlights the significance of stochasticity for distinguishing between different modes of stem cell division.

Chinese herbal medicine for the treatment of small intestinal bacterial overgrowth (SIBO): A protocol for systematic review and meta-analysis.

BACKGROUND: Chinese medicine has a unique theory and the Chinese herbal medicine treatment is based on the integral concepts and syndrome differentiation of the Traditional Chinese Medicine system. Although antibiotics remain the mainstay of SIBO treatment, various alternative or adjunctive therapies are available, including prokinetic agents, dietary interventions, probiotics, and herbal combinations. There is accumulating evidence demonstrating the antimicrobial properties of a growing number of herbs including garlic, black cumin, cloves, cinnamon, thyme, all-spices, bay leaves, mustard, and rosemary. This has prompted an interest in herbal therapy for the treatment of SIBO. Currently, there is no systematic review focusing on efficacy of CHM in the treatment of SIBO with PCOS, so our meta-analysis aims to comprehensively explore it. Meanwhile we will provide high-quality evidence to help patients, clinicians as well as health policymakers select better treatment strategy of PCOS. METHODS: We will search the following sources without restrictions for date, language, or publication status: PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL) Cochrane Library, EMBASE and China National Knowledge Infrastructure. We will apply a combination of Medical Subject Heading (MeSH) and free-text terms incorporating database-specific controlled vocabularies and text words to implement search strategies. We will also search the ongoing trials registered in the World Health Organization's International Clinical Trials Registry Platform. Besides, the previous relevant reviews conducted on CHM for SIBO and reference lists of included studies will also be searched. RESULTS: This study will provide a reliable basis for the treatment of SIBO with CHM. CONCLUSIONS: The findings will be an available reference to evaluate the efficacy and safety of CHM in the treatment of SIBO. REGISTRATION NUMBER: INPLASY202080004.

Methanolic extract of Tamarix Gallica attenuates hyperhomocysteinemia induced AD-like pathology and cognitive impairments in rats.

Although few drugs are available today for the management of Alzheimer's disease (AD) and many plants and their extracts are extensively employed in animals' studies and AD patients, yet no drug or plant extract is able to reverse AD symptoms adequately. In the present study, Tamarix gallica (TG), a naturally occurring plant known for its strong antioxidative, anti-inflammatory and anti-amyloidogenic properties, was evaluated on homocysteine (Hcy) induced AD-like pathology and cognitive impairments in rats. We found that TG attenuated Hcy-induced oxidative stress and memory deficits. TG also improved neurodegeneration and neuroinflammation by upregulating synaptic proteins such as PSD95 and synapsin 1 and downregulating inflammatory markers including CD68 and GFAP with concomitant decrease in proinflammatory mediators interlukin-1ß (IL1ß) and tumor necrosis factor α (TNFα). TG attenuated tau hyperphosphorylation at multiple AD-related sites through decreasing some kinases and increasing phosphatase activities. Moreover, TG rescued amyloid-ß (Aß) pathology through downregulating BACE1. Our data for the first time provide evidence that TG attenuates Hcy-induced AD-like pathological changes and cognitive impairments, making TG a promising candidate for the treatment of AD-associated pathological changes.

Moringa Oleifera Alleviates Homocysteine-Induced Alzheimer's Disease-Like Pathology and Cognitive Impairments.

Alzheimer's disease (AD) is multifactorial with unclear etiopathology. Due to the complexity of AD, many attempted single therapy treatments, like Aß immunization, have generally failed. Therefore, there is a need for drugs with multiple benefits. Naturally occurring phytochemicals with neuroprotective, anti-amyloidogenic, antioxidative, and anti-inflammatory properties could be a possible way out. In this study, the effect of Moringa oleifera (MO), a naturally occurring plant with high antioxidative, anti-inflammatory, and neuroprotective effects, was evaluated on hyperhomocysteinemia (HHcy) induced AD-like pathology in rats. Homocysteine (Hcy) injection for 14 days was used to induce AD-like pathology. Simultaneous MO extract gavage followed the injection as a preventive treatment or, after injection completion, MO gavage was performed for another 14 days as a curative treatment. MO was found to not only prevent but also rescue the oxidative stress and cognitive impairments induced by Hcy treatment. Moreover, MO recovered the decreased synaptic proteins PSD93, PSD95, Synapsin 1 and Synaptophysin, and improved neurodegeneration. Interestingly, MO decreased the Hyc-induced tau hyperphosphorylation at different sites including S-199, T-231, S-396, and S-404, and at the same time decreased Aß production through downregulation of BACE1. These effects in HHcy rats were accompanied by a decrease in calpain activity under MO treatment, supporting that calpain activation might be involved in AD pathogenesis in HHcy rats. Taken together, our data, for the first time, provided evidence that MO alleviates tau hyperphosphorylation and Aß pathology in a HHcy AD rat model. This and previous other studies support MO as a good candidate for, and could provide new insights into, the treatment of AD and other tauopathies.

High salt induced hypertension leads to cognitive defect.

Although increasing evidences suggest a relationship between hypertension and brain function for years, it is still unclear whether hypertension constitutes a risk factor for cognitive decline and its underlying mechanism. In the present study, an experimental animal model of hypertension simply by feeding rats with high salt diet was employed. We found that long-term high salt intake caused a marked increase of systolic blood pressure linked to a declined regional cerebral blood flow. Fear conditioning and morris water maze behavioral test revealed that high salt diet induced hippocampal dependent spatial reference memory deficits, while a decreased synaptogenesis without neuronal loss in hippocampus was observed in high salt treated rats. Furthermore, we found that high salt induced a decrease of intracellular calcium, which inactivated CaMK II and resulted in dephosphorylation of CREB at Ser133. These findings suggest a novel etiopathogenic mechanism of cognitive deficit induced by hypertension, which is initiated by high salt diet.

Synthesis and applications of poly(acryl p-aminobenzenesulfonamideamidine- p-aminobenzenesulfonylamide) chelating fiber for pre-concentrating and separating trace Bi(III), Hg(III), Au(III) and Pd(IV) from solution samples.

Poly(acryl p-aminobenzenesulfonamideamidine- p-aminobenzenesulfonylamide) chelating fiber containing "S", "N", and "O" elements was synthesized from polyacrylonitrile fiber and p-aminobenzene sulfonamide and used to enrich and separate trace Bi(III), Hg(III), Au(III), and Pd(IV) ions from wastewater and ore sample solution. The enrichment acidity, flow rate, elution conditions, reuse, interference ions, saturated adsorption capacity, constant of adsorption rate, analytical accuracy, and actual samples on chelating fiber were investigated by means of inductively coupled plasma optical emission spectrometry (ICP-OES) with satisfactory results. Solutions of 100 ng mL(-1) of Bi(III), Hg(III), Au(III), and Pd(IV) ions can be enriched quantitatively by this chelating fiber at a rate of 1.0 mL min(-1) at pH 4 and desorbed quantitatively with 20 mL of 0.25 M HCl and 2% CS(NH(2))(2) solution at 50 degrees C (with recovery >/=97%). When the chelating fiber was reused for 20 times, the recoveries of the analyzed ions enriched by the fiber were still over 95% (except for Hg(III)). One thousand-fold excesses of Mn(2+), Ca(2+), Zn(2+), Mg(2+), Fe(3+), Cu(2+), Ni(2+), Al(3+), and Ba(2+) ions and thousands-fold excesses of Na(+ )and K(+) cause little interference in the pre-concentration and determination of the analyzed ions. The saturated adsorption capacity of Bi(III), Hg(III), Au(III), and Pd(IV) was 4.850 x 10(-4), 3.235 x 10(-4), 2.807 x 10(-4), and 3.386 x 10(-4) mol g(-1), respectively. The constants of adsorption rate were 0.409 min(-1) for Bi, 0.122 min(-1) for Hg, 0.039 min(-1) for Au, and 0.080 min(-1 )for Pd. The relative standard deviations (RSDs) for the enrichment and determination of 10 ng mL(-1) Bi(III), Hg(III), Au(III), and Pd(IV) were lower than 2.3%. The results obtained for these ions in actual samples by this method were basically in agreement with the given values with average errors of less than 1.0%. FT-IR spectra shows that the existence of -SO(2)-Ar, -H(2)N-Ar, O=C-NH-, HN=C-NH-, and -HN-SO(2) functional groups are verified in the chelating fiber. From the FT-IR spectroscopy, we can see that Hg(III), Au(III), and Pd(IV) are mainly combined with nitrogen and sulfur (or oxygen), and Bi(III) is mainly combined with nitrogen (or oxygen) of the groups to form a chelating complex.