Exploring the role of smart cities in supporting ageing-in-place in Chongqing, China.

OBJECTIVE: Through interviews with older adults and professionals in Chongqing, China, this paper explores the challenges and opportunities faced by smart cities that undertake to better support ageing-in-place. METHODS: We undertook a qualitative multi-methods approach, engaging 46 professional stakeholders and 64 older people to examine the role of smart cities in enabling older people to age-in-place in Chongqing, China. RESULTS: With the development of smart cities, technology has the potential to facilitate ageing-in-place by creating opportunities for heathy and active ageing. This study identified specific priorities in delivering age-friendly smart cities, including the following: shaping smart environments around the everyday lives of older people, designing inclusive and equitable smart cities and ensuring strong forms of institutional governance, trust and relationship building with older people. CONCLUSIONS: The age-friendly city and communities movement (AFCC) and smart city policy instruments have potential for realising active ageing by supporting mobility, access to services and civic participation. However, there exists a disconnect between smart city policy and practice in delivering tangible well-being outcomes for older people. Addressing this requires greater cross-sectoral working, reconciling smart city policy priorities with AFCC domains and creating the institutional and governance framework to enable socially sustainable cities to support ageing-in-place.

Protoberberine alkaloids: A review of the gastroprotective effects, pharmacokinetics, and toxicity.

BACKGROUND: Stomach diseases have become global health concerns. Protoberberine alkaloids (PBAs) are a group of quaternary isoquinoline alkaloids from abundant natural sources and have been shown to improve gastric disorders in preclinical and clinical studies. The finding that PBAs exhibit low oral bioavailability but potent pharmacological activity has attracted great interest. PURPOSE: This review aims to provide a systematic review of the molecular mechanisms of PBAs in the treatment of gastric disorders and to discuss the current understanding of the pharmacokinetics and toxicity of PBAs. METHODS: The articles related to PBAs were collected from the Web of Science, Pubmed, and China National Knowledge Infrastructure databases using relevant keywords. The collected articles were screened and categorized according to their research content to focus on the gastroprotective effects, pharmacokinetics, and toxicity of PBAs. RESULTS: Based on the results of preclinical studies, PBAs have demonstrated therapeutic effects on chronic atrophic gastritis and gastric cancer by activating interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6) pathway and suppressing transforming growth factor-beta 1 (TGF-ß1)/phosphoinositide 3-kinase (PI3K), Janus kinase-2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), and mitogen-activated protein kinase (MAPK) pathways. The major PBAs exhibit similar pharmacokinetic properties, including rapid absorption, slow elimination, and low bioavailability. Notably, the natural organ-targeting property of PBAs may account for the finding of their low blood levels and high pharmacological activity. PBAs interact with other compounds, including conventional drugs and natural products, by modulation of metabolic enzymes and transporters. The potential tissue toxicity of PBAs should be emphasized due to their high tissue accumulation. CONCLUSION: This review highlights the gastroprotective effects, pharmacokinetics, and toxicity of PBAs and will contribute to the evaluation of drug properties and clinical translational studies of PBAs, accelerating their transfer from the laboratory to the bedside.

Dietary gallic acid as an antioxidant: A review of its food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions.

Gallic acid (GA), a dietary phenolic acid with potent antioxidant activity, is widely distributed in edible plants. GA has been applied in the food industry as an antimicrobial agent, food fresh-keeping agent, oil stabilizer, active food wrap material, and food processing stabilizer. GA is a potential dietary supplement due to its health benefits on various functional disorders associated with oxidative stress, including renal, neurological, hepatic, pulmonary, reproductive, and cardiovascular diseases. GA is rapidly absorbed and metabolized after oral administration, resulting in low bioavailability, which is susceptible to various factors, such as intestinal microbiota, transporters, and metabolism of galloyl derivatives. GA exhibits a tendency to distribute primarily to the kidney, liver, heart, and brain. A total of 37 metabolites of GA has been identified, and decarboxylation and dihydroxylation in phase I metabolism and sulfation, glucuronidation, and methylation in phase Ⅱ metabolism are considered the main in vivo biotransformation pathways of GA. Different types of nanocarriers, such as polymeric nanoparticles, dendrimers, and nanodots, have been successfully developed to enhance the health-promoting function of GA by increasing bioavailability. GA may induce drug interactions with conventional drugs, such as hydroxyurea, linagliptin, and diltiazem, due to its inhibitory effects on metabolic enzymes, including cytochrome P450 3A4 and 2D6, and transporters, including P-glycoprotein, breast cancer resistance protein, and organic anion-transporting polypeptide 1B3. In conclusion, in-depth studies of GA on food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions have laid the foundation for its comprehensive application as a food additive and dietary supplement.

CellBiAge: Improved single-cell age classification using data binarization.

Aging is a major risk factor for many diseases. Accurate methods for predicting age in specific cell types are essential to understand the heterogeneity of aging and to assess rejuvenation strategies. However, classifying organismal age at single-cell resolution using transcriptomics is challenging due to sparsity and noise. Here, we developed CellBiAge, a robust and easy-to-implement machine learning pipeline, to classify the age of single cells in the mouse brain using single-cell transcriptomics. We show that binarization of gene expression values for the top highly variable genes significantly improved test performance across different models, techniques, sexes, and brain regions, with potential age-related genes identified for model prediction. Additionally, we demonstrate CellBiAge's ability to capture exercise-induced rejuvenation in neural stem cells. This study provides a broadly applicable approach for robust classification of organismal age of single cells in the mouse brain, which may aid in understanding the aging process and evaluating rejuvenation methods.

Fabrication of pH-dependent solid dispersion for oral colon-targeted delivery of notoginsenoside R1 and its protective effects on ulcerative colitis mice.

Notoginsenoside R1 (R1), which originated from the rhizomes and roots of Panax notoginseng, is classified as a Biopharmaceutical Classification System class III drug with good solubility but poor oral absorption. Although R1 can alleviate the inflammation of dextran sulfate sodium (DSS)-induced colitis in mice, the problem of acid degradation and low bioavailability limit its application. The purpose of this study was aimed to design one kind of pH-dependent solid dispersion for oral colon-targeted delivery of R1. Using Eudragit S100 (ES 100) and PEG 4000 as the pH-dependent carriers, R1 solid dispersion (R1-SD) was fabricated by solvent evaporation method. Scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction analysis indicated that R1-SD was completely formed, the surface was smooth surface and the strip crystal structure of R1 disappeared. The in vitro release profile of R1-SD (R1-ES 100-PEG 4000, 1:7:1, weight ratio) exhibited that R1-SD was not released in media simulating the gastric condition (pH 1.2), but better release characteristics of the drug could be obtained in media simulating the intestinal condition (less than 30% in pH 6.8 phosphate-buffered saline and more than 90% in pH 7.6 condition). The in vitro colon absorption test showed that the absorption rate and cumulative release of R1-SD were higher than those of R1. R1-SD and R1 had apparent protective effect on colon shortening, inflammatory infiltrating tissue injury, weight loss, diarrhea, blood stool in mice with ulcerative colitis induced by DSS, and the protective effect of R1-SD was better than that of R1, which indicated R1-SD has good practical application prospects.

Metabolism and toxicity of usnic acid and barbatic acid based on microsomes, S9 fraction, and 3T3 fibroblasts in vitro combined with a UPLC-Q-TOF-MS method.

Introduction: Usnic acid (UA) and barbatic acid (BA), two typical dibenzofurans and depsides in lichen, have a wide range of pharmacological activities and hepatotoxicity concerns. This study aimed to clarify the metabolic pathway of UA and BA and illuminate the relationship between metabolism and toxicity. Methods: An UPLC-Q-TOF-MS method was developed for metabolite identification of UA and BA in human liver microsomes (HLMs), rat liver microsomes (RLMs), and S9 fraction (RS9). The key metabolic enzymes responsible for UA and BA were identified by enzyme inhibitors combined with recombinant human cytochrome P450 (CYP450) enzymes. The cytotoxicity and metabolic toxicity mechanism of UA and BA were determined by the combination model of human primary hepatocytes and mouse 3T3 fibroblasts. Results: The hydroxylation, methylation, and glucuronidation reactions were involved in the metabolic profiles of UA and BA in RLMs, HLMs, and RS9. CYP2C9, CYP3A4, CYP2C8, and UGT1A1 are key metabolic enzymes responsible for metabolites of UA and CYP2C8, CYP2C9, CYP2C19, CYP1A1, UGT1A1, UGT1A3, UGT1A7, UGT1A8, UGT1A9, and UGT1A10 for metabolites of BA. UA and BA did not display evident cytotoxicity in human primary hepatocytes at concentrations of 0.01-25 and 0.01-100 µM, respectively, but showed potential cytotoxicity to mouse 3T3 fibroblasts with 50% inhibitory concentration values of 7.40 and 60.2 µM. Discussion: In conclusion, the attenuated cytotoxicity of BA is associated with metabolism, and UGTs may be the key metabolic detoxification enzymes. The cytotoxicity of UA may be associated with chronic toxicity. The present results provide important insights into the understanding of the biotransformation behavior and metabolic detoxification of UA and BA.

Isotoosendanin exerts inhibition on triple-negative breast cancer through abrogating TGF-ß-induced epithelial-mesenchymal transition via directly targeting TGFßR1.

As the most aggressive breast cancer, triple-negative breast cancer (TNBC) is still incurable and very prone to metastasis. The transform growth factor ß (TGF-ß)-induced epithelial-mesenchymal transition (EMT) is crucially involved in the growth and metastasis of TNBC. This study reported that a natural compound isotoosendanin (ITSN) reduced TNBC metastasis by inhibiting TGF-ß-induced EMT and the formation of invadopodia. ITSN can directly interact with TGF-ß receptor type-1 (TGFßR1) and abrogated the kinase activity of TGFßR1, thereby blocking the TGF-ß-initiated downstream signaling pathway. Moreover, the ITSN-provided inhibition on metastasis obviously disappeared in TGFßR1-overexpressed TNBC cells in vitro as well as in mice bearing TNBC cells overexpressed TGFßR1. Furthermore, Lys232 and Asp351 residues in the kinase domain of TGFßR1 were found to be crucial for the interaction of ITSN with TGFßR1. Additionally, ITSN also improved the inhibitory efficacy of programmed cell death 1 ligand 1 (PD-L1) antibody for TNBC in vivo via inhibiting the TGF-ß-mediated EMT in the tumor microenvironment. Our findings not only highlight the key role of TGFßR1 in TNBC metastasis, but also provide a leading compound targeting TGFßR1 for the treatment of TNBC metastasis. Moreover, this study also points out a potential strategy for TNBC treatment by using the combined application of anti-PD-L1 with a TGFßR1 inhibitor.

A randomized controlled trial of Baduanjin exercise to reduce the risk of atherosclerotic cardiovascular disease in patients with prediabetes.

To investigate the effectiveness of long-term Baduanjin and aerobic training on the 10-year risk of atherosclerotic cardiovascular disease in prediabetic patients. This study was single-blind randomized controlled trial. A total of 98 participants with prediabetes were randomly divided into three groups: the BDJ (n = 34), AT (n = 32), and control (n = 32) groups. Participants in the BDJ and AT groups underwent one year of supervised group exercise, consisting of 60 min/session every other day. The primary outcomes were metabolic control and the 10-year risk of ASCVD. The secondary outcome was a change in blood glucose status. After the intervention, various metabolic indexes were significantly improved in the two exercise groups relative to the control group and baseline measurements (p < 0.05). Compared with no exercise, BDJ and AT had significant preventive and protective effects against the risk of ASCVD in patients with prediabetes (p < 0.001). The overall effects of the two exercise groups were similar (p > 0.05). Long-term BDJ training can effectively reduce the risk of type 2 diabetes mellitus (T2DM) and its cardiovascular complications in prediabetic patients. The effect of BDJ is similar to that of moderate-intensity aerobic exercise.

The protective effect of Buzhong Yiqi decoction on ischemic stroke mice and the mechanism of gut microbiota.

Buzhong Yiqi decoction (BZYQD) has been developed for preventing or reducing the recurrence of ischemic stroke for a long time in China. However, the mechanism of action of the BZYQD is not completely understood. Our research aims to determine whether the mechanism of action of BZYQD is by regulating gut microbiota using 16SR RNA and fecal microbiota transplantation. In a cerebral ischemia mouse model, the results showed that prophylactic administration of BZYQD could reduce brain infarct volume and improve neurological function and behavior. The prophylactic administration of BZYQD could regulate intestinal microbiota and increase the abundance of butyrate-producing Prevotellaceae_NK3B31_group and probiotic Akkermansia in mice 72 h after surgery. Transplanting BZYQD-administered bacterial flora into antibiotic-depleted mice could reproduce the therapeutic effects of BZYQD. Overall, our study provided molecular insights into the mechanism and impact of BZYQD in the prevention of cerebral ischemic damage and highlighted the potential of regulation of intestinal microbiota as a therapeutic approach for ischemic stroke.

Simultaneous LC-MS/MS bioanalysis of alkaloids, terpenoids, and flavonoids in rat plasma through salting-out-assisted liquid-liquid extraction after oral administration of extract from Tetradium ruticarpum and Glycyrrhiza uralensis: a sample preparation strategy to broaden analyte coverage of herbal medicines.

Herbal medicines have historically been practiced in combinatorial way, which achieves therapeutic efficacy by integrative effects of multi-components. Thus, the accurate and precise measurement of multi bioactive components in matrices is inalienable to understanding the metabolism and disposition of herbal medicines. In this study, aiming to provide a strategy that improves analyte coverage, evaluation of six protocols employing sample pretreatment methods- protein precipitation (PPT), liquid-liquid extraction (LLE), sugaring-out-assisted liquid-liquid extraction (SULLE), and salting-out-assisted liquid-liquid extraction (SALLE)- was performed by LC-MS/MS using rat plasma and a mixture of alkaloid (evodiamine, rutaecarpine, dehydroevodiamine), terpenoid (limonin, rutaevin, obacunone), and flavonoid (liquiritin, isoliquiritin, liquiritigenin) standards isolated from Tetradium ruticarpum and Glycyrrhiza uralensis. These protocols were as follows: (1) PPT with methanol, (2) PPT with acetonitrile, (3) LLE with methyl tertiary-butyl ether-dichloromethane, (4) LLE with ethyl acetate-n-butanol, (5) SALLE with ammonium acetate, (6) SULLE with glucose. The results suggested that SALLE produced broader analyte coverage with satisfactory reproducibility, acceptable recovery, and low matrix interference. Then, sample preparation procedure of SALLE, chromatographic conditions, and mass spectrometric parameters were optimized, followed by method validation, showing that good sensitivity (LLOQ ≤ 1 ng mL-1), linearity (r ≥ 0.9933), precision (RSD ≤ 14.45%), accuracy (89.54~110.87%), and stability could be achieved. Next, the developed method was applied successfully to determine the pharmacokinetic behavior of the nine compounds in rat plasma after intragastric administration with an extract from Tetradium ruticarpum and Glycyrrhiza uralensis (Wuzhuyu-Gancao pair). Based on an extensive review and experiments, a sample preparation procedure that matches with LC-MS/MS technique and can get wider analyte coverage was outlined. The developed SALLE method is rapid, reliable, and suitable for bioanalysis of analytes with diverse polarity, which was expected to be a promising strategy for the pharmacokinetic studies of herbal medicines. Graphical abstract.

Chitosan crosslinked with polyamine-co-melamine for adsorption of Hg2+: Application in purification of polluted water.

A batch experiment was carried out in order to remove Hg2+ from the aqueous solution as well as the polluted water using modified chitosan (CS) with polyamine compounds (triethylenetetramine (TETA), tetraethylenepentamine (TEPA)), and melamine. The obtained polyamine-co-melamine crosslinked CS derivatives (MCS-4N and MCS-5N) were characterized and used as adsorbents. In comparison to the raw CS, the modification significantly promoted the adsorption of Hg2+ ions. The results of the pseudo-second-order kinetic model revealed that pH-dependent derivatives adsorbents achieved the equilibrium state within 12 h. The Langmuir model was best fitted with the Hg2+ adsorption isotherm and showed the highest adsorption capacities of 140.3 and 109.7 mg/g for MCS-4N and MCS-5N, respectively. A slight decrease in the adsorption efficiency of Hg2+ was noticed with the increment of the ionic strength of the solution. However, the studied adsorbents were easily regenerated and presented adequate reusability. The Hg2+ adsorption was regulated by the combined process of coordination reaction and electrostatic attraction as well. The as-prepared polyamine-co-melamine crosslinked CS derivatives were found potential adsorbents for the adsorptive capture of Hg2+ ions from aqueous solutions and polluted waters.

Experiences of Older People and Social Inclusion in Relation to Smart "Age-Friendly" Cities: A Case Study of Chongqing, China.

Whilst cities can be sites of creativity, innovation, and change, they can also reproduce the conditions for the exclusion of vulnerable groups. Older people report experiencing specific barriers to accessing the city and are often excluded from the resources for ageing well. The smart city agenda has attempted to bring about technological change whilst also delivering improved quality of life for urban citizens. Smart technologies are a key element of the smart city and are viewed as having the potential to support the independence, autonomy, and well-being of older people. Yet, there has been little research exploring the role of the smart city in supporting the social inclusion of older people, nor any attempt to link this with key policy drivers on ageing e.g., age-friendly cities and communities. In response, the aim of this paper is to explore the experiences of older people living in a smart city in China and discuss how the smart city and age-friendly agenda can be brought together to support positive social outcomes for older people. The paper presents qualitative findings from a multi-methods approach, including semi-structured interviews, walking interviews and focus groups. A total of 64 older people participated in the research across three diverse neighbourhoods in the case study smart city of Chongqing, China. The findings identified opportunities in the development and deployment of smart city, including the potential for improved health and well-being and social connectedness. Yet in delivering on these benefits, a number of challenges were identified which may widen social inequalities, including inequities in access, issues of safety and security, and exclusion from the co-production of smart city policy and practise. The paper discusses the implications of the findings for future smart city policy and practise, specifically in delivering interventions that support older adults' social inclusion and the delivery of age-friendly cities and communities.

Dynamic Changes of Endogenic or Exogenic ß-Carboline Alkaloid Harmine in Different Mammals and Human in vivo at Developmental and Physiological States.

OBJECTIVE: Several ß-carboline alkaloids (ßCBs), such as harmine, harmaline, harmane, and nor-harmane, are effective for Alzheimer's disease mouse models. They can be found in some plants, common foodstuffs, and blank plasma of various mammals. However, whether these compounds in mammals are exogenous or endogenous remain unclear. METHODS: The exposure levels of ßCBs and of neurotransmitters in plasma and tissues of pup rats, aging rats, mice of different physiological states, and healthy volunteers were detected by using UPLC-MS/MS. Plasma and tissue samples from 110 newborn rats up to 29 days old at 11 sampling points were collected and were analyzed to determine the concentration variation of ßCBs in the developmental phase of newborn rats. The plasma of rats aged 2 to 18 months was used to detect the variation trend of ßCBs and with some neurotransmitters. The plasma samples of normal C57BL/6 mice, APP/PS1 double transgenic mice, and scopolamine-induced memory impairment mice were collected and were analyzed to compare the difference of ßCBs in different physiological states. The exposure levels of ßCBs such as harmine, harmaline, and harmane in plasma of 550 healthy volunteers were also detected and analyzed on the basis of gender, race, and age. RESULTS: Results showed that harmine was the main compound found in rats, mice, and human, which can be detected in a newborn rat plasma (0.16 ± 0.03 ng/ml) and brain (0.33 ± 0.14 ng/g) without any exogenous consumption. The concentration of harmine in rat plasma showed a decreasing trend similar to the exposure levels of neurotransmitters such as 5-hydroxytryptamine, acetylcholine chloride, glutamic acid, tyrosine, and phenylalanine during the growth period of 18 months. The harmine exposure in rats and human indicates high dependence on the physiological and pathological status such as aging, gender, and race. CONCLUSION: The dynamic changes of harmine exposure in different animals and human, in vivo, at developmental and physiological states indicate that harmine is a naturally and widely distributed endogenous substance in different mammals and human. In addition to exogenous ingestion, spontaneous synthesis might be another important source of harmine in mammals, which should be verified by further experiment.

Traditional uses, phytochemistry, pharmacology, pharmacokinetics and toxicology of the fruit of Tetradium ruticarpum: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruit of Tetradium ruticarpum (FTR) known as Tetradii fructus or Evodiae fructus (Wu-Zhu-Yu in Chinese) is a versatile herbal medicine which has been prescribed in Chinese herbal formulas and recognized in Japanese Kampo. FTR has been clinically used to treat various diseases such as headache, vomit, diarrhea, abdominal pain, dysmenorrhea and pelvic inflammation for thousands of years. AIM OF THE REVIEW: The present paper aimed to provide comprehensive information on the ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics, drug interaction and toxicology of FTR in order to build up a foundation on the mechanism of ethnopharmacological uses as well as to explore the trends and perspectives for further studies. MATERIALS AND METHODS: This review collected the literatures published prior to July 2020 on the phytochemistry, pharmacology, pharmacokinetics and toxicity of FTR. All relevant information on FTR was gathered from worldwide accepted scientific search engines and databases, including Web of Science, PubMed, Elsevier, ACS, ResearchGate, Google Scholar, and Chinese National Knowledge Infrastructure (CNKI). Information was also obtained from local books, PhD. and MSc. Dissertations as well as from Pharmacopeias. RESULTS: FTR has been used as an herbal medicine for centuries in East Asia. A total of 165 chemical compounds have been isolated so far and the main chemical compounds of FTR include alkaloids, terpenoids, flavonoids, phenolic acids, steroids, and phenylpropanoids. Crude extracts, processed products (medicinal slices) and pure components of FTR exhibit a wide range of pharmacological activities such as antitumor, anti-inflammatory, antibacterial, anti-obesity, antioxidant, insecticide, regulating central nervous system (CNS) homeostasis, cardiovascular protection. Furthermore, bioactive components isolated from FTR can induce drug interaction and hepatic injury. CONCLUSIONS: Therapeutic potential of FTR has been demonstrated with the pharmacological effects on cancer, inflammation, cardiovascular diseases, CNS, bacterial infection and obesity. Pharmacological and pharmacokinetic studies of FTR mostly focus on its main active alkaloids. Further in-depth studies on combined medication and processing approaches mechanisms, pharmacological and toxic effects not limited to the alkaloids, and toxic components of FTR should be designed.

circRNA-UBAP2 promotes the proliferation and inhibits apoptosis of ovarian cancer though miR-382-5p/PRPF8 axis.

OBJECTIVE: circular RNAs (circRNAs) have been reported to be essential regulators of multiple malignant cancers. However, the functions of circRNAs in ovarian cancer need to be further explored. The aim of our study is to explore the role of circRNA-UBAP2 in ovarian cancer and its mechanism. RESULTS: circRNA-UBAP2 was upregulated in ovarian cancer tissues and cell lines. Knockdown of circRNA-UBAP2 inhibited cell proliferation and promoted cell apoptosis, but circRNA-UBAP2 overexpressed got opposite results. In addition, circRNA-UBAP2 targeted miR-382-5p and downregulated its expression, PRPF8 was a target gene of miR-382-5p. Furthemore, circRNA-UBAP2/miR-382-5p/PRPF8 axis affected the proliferation, apoptosis and cell cycle of ovarian cancer through the mechanism of competing endogenous RNAs (ceRNA). CONCLUSION: circRNA-UBAP2 acted as a ceRNA to sponged miR-382-5p, increased the expression level of PRPF8, and prompted proliferation and inhibited apoptosis in ovarian cancer cells.

Modification of Rhizosphere Bacterial Community Structure and Functional Potentials to Control Pseudostellaria heterophylla Replant Disease.

Replant disease caused by negative plant-soil feedback commonly occurs in a Pseudostellaria heterophylla monoculture regime. Here, barcoded pyrosequencing of 16S ribosomal DNA amplicons combined with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis was applied to study the shifts in soil bacterial community structure and functional potentials in the rhizosphere of P. heterophylla under consecutive monoculture and different soil amendments (i.e., bio-organic fertilizer application [MF] and paddy-upland rotation [PR]). The results showed that the yield of tuberous roots decreased under P. heterophylla consecutive monoculture and then increased after MF and PR treatments, which was consistent with the changes in soil bacterial diversity. Both principal coordinate analysis and the unweighted pair-group method with arithmetic means cluster analysis showed the distinct difference in bacterial community structure between the consecutively monocultured soil (relatively unhealthy soil) and other relatively healthy soils (i.e., newly planted soil, MF, and PR). Furthermore, taxonomic analysis showed that consecutive monoculture of P. heterophylla significantly decreased the relative abundances of the families Burkholderiaceae and Acidobacteriaceae (subgroup 1), whereas it increased the population density of families Xanthomonadaceae, Phyllobacteriaceae, Sphingobacteriaceae, and Alcaligenaceae, and Fusarium oxysporum. In contrast, the MF and PR treatments recovered the soil microbiome and decreased F. oxysporum abundance through the different ways; for example, the introduction of beneficial microorganisms (in MF) or the switching between anaerobic and aerobic conditions (in PR). In addition, PICRUSt analysis revealed the higher abundances of membrane transport, cell motility, and DNA repair in the consecutively monocultured soil, which might contribute to the root colonization and survival for certain bacterial pathogens under monoculture. These findings highlight the close association between replant disease of P. heterophylla and the variations in structure and potential functions of rhizosphere bacterial community.

Polyamine-co-2, 6-diaminopyridine covalently bonded on chitosan for the adsorptive removal of Hg(II) ions from aqueous solution.

In the present study, 2, 6-diaminopyridine (PD) and polyamine compounds (ethylenediamine (EDA), triethylenetetramine (TETA), and tetraethylenepentamine (TEPA)) were used to modify chitosan (CS). The obtained derivatives (PD-CS, PD-EDA-CS, PD-TETA-CS, and PD-TEPA-CS) were identified and employed as adsorbents in batch experiments for the removal of Hg(II) from aqueous solutions. The results confirmed that successful modification improves the Hg(II) adsorption significantly compared to pristine CS. The adsorbed amounts of Hg(II) increased gradually and reached maxima at pH values above 4.0 for all derivatives. The Hg(II) adsorption equilibrium state was achieved within 12 h, with the process driven by a pseudo-second-order kinetic model. The Langmuir model effectively interpreted the Hg(II) adsorption isotherms; the maximum adsorption capacities for Hg(II) ions at 295 K were 172.7, 303.6, 276.0, and 230.6 mg/g for PD-CS, PD-EDA-CS, PD-TETA-CS, and PD-TEPA-CS, respectively. High temperature and low ionic strength favored Hg(II) adsorption. The Hg(II)-loaded CS derivative was easily regenerated and showed acceptable reusability. The further FT-IR and XPS analyses indicate that the Hg(II) adsorption is governed by a process combining electrostatic attraction and a coordination reaction. The CS derivatives produced from polyamine-co-2, 6-diaminopyridine covalently bonded onto CS are promising adsorbents for the adsorptive removal of Hg(II) from an aqueous solution.

Decontamination of Hg(II) from aqueous solution using polyamine-co-thiourea inarched chitosan gel derivatives.

Ethylenediamine (EDA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA) had been successfully introduced into the structure of thiourea (TC) modified chitosan (CS) by using formaldehyde as linkage, respectively. The resulted materials, TC-CS, TC-EDA-CS, TC-TETA-CS, and TC-TEPA-CS were characterized and employed as adsorbents in batch experiment for the Hg(II) removal. We have found the modification enhanced the Hg(II) adsorption significantly in comparison with raw CS. Hg(II) adsorption amounts for all adsorbents increased gradually and reached maxima at pH≥4.0. The adsorption of Hg(II) achieved an equilibrium state within 12h with the process drove by the pseudo-second-order model. The ionic strength had no remarkable inhibition effect on Hg(II) adsorption. While the Hg(II) adsorption capacities of the adsorbents were strongly related with the modifier types and the length of the incorporating amino ligands. Langmuir model described Hg(II) adsorption well with the maximum adsorption capacities of prepared adsorbents in order of TC-EDA-CS (217.1mg/g)>TC-CS (164.8mg/g)>TC-TETA-CS (149.7mg/g)>TC-TEPA-CS (140.6mg/g) at room temperature. The FT-IR and XPS investigations implied that Hg(II) ion adsorption mechanism was characterized by a complexation reaction process. Adsorbents could be readily regenerated and had great reusability potential in Hg(II) ions capture from aqueous solution.

Removal of Cd(II) and Cr(VI) ions by highly cross-linked Thiocarbohydrazide-chitosan gel.

A highly cross-linked Thiocarbohydrazide-modified chitosan (TCCS) gel was synthesized by using formaldehyde as linkage, and was used in removal of Cd(II) and Cr(VI) from aqueous solution. The results showed that TCCS could be used in a wider pH range and had higher adsorption abilities than raw chitosan for Cd(II) and Cr(VI) ions. The maximum adsorption capacities of the synthetic TCCS for two ions reached 81.26 and 144.68mg/g at 298K, respectively. The endothermic adsorption exhibited pseudo-second-order kinetic behavior and the adsorption isotherm could be well described by Langmuir model. The Cd(II) ion adsorption mechanism was dominated by a complexation reaction process, while the Cr(VI) adsorption was governed by a multiple mechanism including electrostatic attraction, reduction and complexation process. TCCS was easy to be regenerated and had great reusability potential in Cd(II) and Cr(VI) ions capture from aqueous solution.