Displaying publications 261 - 280 of 416 in total

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  1. Zhou C, Yu T, Zhu R, Lu J, Ouyang X, Zhang Z, et al.
    Int J Biol Sci, 2023;19(5):1471-1489.
    PMID: 37056925 DOI: 10.7150/ijbs.77979
    Timosaponin AIII (Tim-AIII), a steroid saponin, exhibits strong anticancer activity in a variety of cancers, especially breast cancer and liver cancer. However, the underlying mechanism of the effects of Tim-AIII-mediated anti-lung cancer effects remain obscure. In this study, we showed that Tim-AIII suppressed cell proliferation and migration, induced G2/M phase arrest and ultimately triggered cell death of non-small cell lung cancer (NSCLC) cell lines accompanied by the release of reactive oxygen species (ROS) and iron accumulation, malondialdehyde (MDA) production, and glutathione (GSH) depletion. Interestingly, we found that Tim-AIII-mediated cell death was reversed by ferroptosis inhibitor ferrostatin-1 (Fer-1). Meanwhile, the heat shock protein 90 (HSP90) was predicted and verified as the direct binding target of Tim-AIII by SwissTargetPrediction (STP) and surface plasmon resonance (SPR) assay. Further study showed that Tim-AIII promoted HSP90 expression and Tim-AIII induced cell death was blocked by the HSP90 inhibitor tanespimycin, indicating that HSP90 was the main target of Tim-AIII to further trigger intracellular events. Mechanical analysis revealed that the Tim-AIII-HSP90 complex further targeted and degraded glutathione peroxidase 4 (GPX4), and promoted the ubiquitination of GPX4, as shown by an immunoprecipitation, degradation and in vitro ubiquitination assay. In addition, Tim-AIII inhibited cell proliferation, induced cell death, led to ROS and iron accumulation, MDA production, GSH depletion, as well as GPX4 ubiquitination and degradation, were markedly abrogated when HSP90 was knockdown by HSP90-shRNA transfection. Importantly, Tim-AIII also showed a strong capacity of preventing tumor growth by promoting ferroptosis in a subcutaneous xenograft tumor model, whether C57BL/6J or BALB/c-nu/nu nude mice. Together, HSP90 was identified as a new target of Tim-AIII. Tim-AIII, by binding and forming a complex with HSP90, further targeted and degraded GPX4, ultimately induced ferroptosis in NSCLC. These findings provided solid evidence that Tim-AIII can serve as a potential candidate for NSCLC treatment.
    Matched MeSH terms: Iron/metabolism
  2. Paul S, Ali MY, Rumpa NE, Tanvir EM, Hossen MS, Saha M, et al.
    PMID: 28243309 DOI: 10.1155/2017/4686104
    This study was undertaken to investigate the toxicological profile of a methanolic extract of Garcinia pedunculata fruit in rats by conducting hematological, biochemical, and histopathological examinations. Long Evans rats were divided into four groups, each with 6 animals, and were treated with three oral doses (250, 500, and 1000 mg/kg) once daily for 21 days. The extract did not cause significant changes in body and relative organ weight, percent water content, or hematological parameters at any administered doses. However, a significant dose-dependent positive effect in serum lipid profile and all atherogenic indices including the cardiac risk ratio, Castelli's risk index-2, and the atherogenic coefficient were observed. Significant increases in the levels of iron and decreases in serum alkaline phosphatase, alanine transaminase, and lactate dehydrogenase activities and the levels of serum glucose were noted when the extract was administered at the highest dose (1000 mg/kg). Histopathological examination of the target tissues further confirmed that the extract was safe and had no observed toxicological features. Our study indicates that G. pedunculata fruit is nontoxic, has the potential to be effective against atherosclerosis, and may be used as a hepatoprotectant. The fruit extract is also beneficial to those with iron deficiency and hyperglycemia.
    Matched MeSH terms: Iron; Anemia, Iron-Deficiency
  3. Hwa WE, Subramaniam G, Mansor MB, Yan OS, Gracie, Anbazhagan D, et al.
    Indian J Med Res, 2010 Apr;131:578-83.
    PMID: 20424311
    Carbapenem-resistant Acinetobacter spp. have gained increasing significance as opportunistic pathogens in hospitalized patients. Carbapenem resistance is often associated with the loss and/or decrease in outer membrane proteins (OMP) and overexpression of multidrug efflux systems. However, carbapenem-hydrolysing beta-lactamases of Ambler Class B (metallo-enzymes) and Ambler Class D (oxacillinases) have also been detected in Acinetobacter spp. In this study we have investigated the role of the iron regulated outer membrane protein (IROMPs) and the loss of a 29-kDa OMP in carbapenem resistance of Acinetobacter calcoaceticus.
    Matched MeSH terms: Iron/physiology*
  4. Arumugam K, Yip YC
    Fertil Steril, 1995 Jul;64(1):62-4.
    PMID: 7789581
    OBJECTIVE: To show that raised iron levels in the peritoneal fluid (PF) of patients with endometriosis catalyze free radical reactions that results in the tissue destruction and fibrosis seen in these patients.

    DESIGN: A case-controlled study of the iron levels (microgram/mL) in the pelvic PF of 12 patients with moderate-to-severe disease, 15 patients with minimal-to-mild disease and in 17 women with normal pelvises were compared. As an index of free radical reactions through lipid peroxidation, the levels of malondialdehyde levels (ng/mL) were assessed simultaneously in the same specimens.

    RESULTS: Controlling for the phase of the menstrual cycle, significantly higher levels of iron were seen in patients with endometriosis, the levels being correlated with the severity of the disease. However no such corresponding relationship was seen in the malondialdehyde levels in the PF.

    CONCLUSIONS: These results suggest that raised iron levels in the PF do not play a role in catalyzing free radical reactions as judged by the degree of lipid peroxidation.

    Matched MeSH terms: Iron/metabolism*
  5. Porter JB, El-Alfy M, Viprakasit V, Giraudier S, Chan LL, Lai Y, et al.
    Eur J Haematol, 2016 Jan;96(1):19-26.
    PMID: 25691036 DOI: 10.1111/ejh.12540
    Plasma markers in addition to serum ferritin (SF) may be useful for the assessment of iron overload; however, predictive utility may differ depending on underlying, transfusion-dependent, anemias.
    Matched MeSH terms: Iron/blood*
  6. Loh TT, Chang LL
    PMID: 7403941
    Non-haemoglobin liver iron was estimated in 275 presumably normal individuals from Kuala Lumpur and Singapore at necropsy. Liver Iron concentrations were highest during the first two years after birth but declined sharply during childhood. They then rose gradually and reached a value of 20 mg/100gm in adult males. Liver iron concentrations of childbearing women remained low and it was only after menopause that values in women rose to those of males. Liver iron stores increased with age to a plateau of about 300 mg in adults, suggesting that this value may represent the adult size for liver iron store. Among the three major ethnic groups in Malaysia and Singapore, Chinese, being in a better socio-eonomic class, had larger liver iron stores. The median liver iron concentrations of Malaysians and Singaporeans, on the whole, were lower than those reported from western populations and as many as 35 per cent of the women were in a subclinical state of iron deficiency.
    Matched MeSH terms: Iron/analysis*
  7. Lee HN, Mostovoy Y, Hsu TY, Chang AH, Brem RB
    G3 (Bethesda), 2013 Dec 09;3(12):2187-94.
    PMID: 24142925 DOI: 10.1534/g3.113.008011
    Comparative genomic studies have reported widespread variation in levels of gene expression within and between species. Using these data to infer organism-level trait divergence has proven to be a key challenge in the field. We have used a wild Malaysian population of S. cerevisiae as a test bed in the search to predict and validate trait differences based on observations of regulatory variation. Malaysian yeast, when cultured in standard medium, activated regulatory programs that protect cells from the toxic effects of high iron. Malaysian yeast also showed a hyperactive regulatory response during culture in the presence of excess iron and had a unique growth defect in conditions of high iron. Molecular validation experiments pinpointed the iron metabolism factors AFT1, CCC1, and YAP5 as contributors to these molecular and cellular phenotypes; in genome-scale sequence analyses, a suite of iron toxicity response genes showed evidence for rapid protein evolution in Malaysian yeast. Our findings support a model in which iron metabolism has diverged in Malaysian yeast as a consequence of a change in selective pressure, with Malaysian alleles shifting the dynamic range of iron response to low-iron concentrations and weakening resistance to extreme iron toxicity. By dissecting the iron scarcity specialist behavior of Malaysian yeast, our work highlights the power of expression divergence as a signpost for biologically and evolutionarily relevant variation at the organismal level. Interpreting the phenotypic relevance of gene expression variation is one of the primary challenges of modern genomics.
    Matched MeSH terms: Iron/metabolism*; Iron/pharmacology
  8. Nemati K, Abu Bakar NK, Abas MR, Sobhanzadeh E, Low KH
    Environ Monit Assess, 2011 May;176(1-4):313-20.
    PMID: 20632089 DOI: 10.1007/s10661-010-1584-3
    A study was carried out to investigate the fractionation of Cd, Cr, Cu, Fe, Mn, Pb, and Zn in shrimp aquaculture sludge from Selangor, Malaysia, using original (unmodified) and modified four-steps BCR (European Community Bureau of Reference, now known as the Standards Measurements and Testing Program) sequential extraction scheme. Step 2 of the unmodified BCR procedure (subsequently called Method A) involves treatment with 0.1 M hydroxylammonium chloride at pH 2, whereas 0.5 M hydroxylammonium chloride at pH 1.5 was used in the modified BCR procedure (subsequently called Method B). Metal analyses were carried out by flame atomic absorption spectrometry. A pseudo-total aqua-regia digest of BCR CRM 701 has also been undertaken for quality assurance purposes. The recovery of Method A for all metals studied ranges from 96.14% to 105.26%, while the recovery for Method B ranges from 95.94% to 122.40%. Our results reveal that Method A underestimated the proportion of metals bound to the easily reducible fraction except for copper. Therefore, the potential mobility of these elements is higher than others. Thus, to use this sludge as a fertilizer we have to first find a remediation for reduction of heavy metal contamination.
    Matched MeSH terms: Environmental Monitoring; Iron/isolation & purification; Iron/chemistry
  9. Goh BL, Ong LM, Sivanandam S, Lim TO, Morad Z, Biogeneric EPO Study Group
    Nephrology (Carlton), 2007 Oct;12(5):431-6.
    PMID: 17803464
    Treatment of renal anaemia with epoetin is well established. However, epoetin is expensive. Biogeneric epoetin with proven efficacy would reduce cost and improve access to therapy. We conducted this first ever comparative study of a biogeneric and the original product.
    Matched MeSH terms: Iron/administration & dosage; Iron/therapeutic use
  10. Shuhaimi-Othman M, Yakub N, Ramle NA, Abas A
    Toxicol Ind Health, 2015 Sep;31(9):773-82.
    PMID: 23302712 DOI: 10.1177/0748233712472519
    Two freshwater fish, Rasbora sumatrana (Cyprinidae) and Poecilia reticulata (guppy; Poeciliidae), were exposed to a range of eight heavy metals (copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn)) at varied concentrations for 96 h in the laboratory. Mortality was assessed and median lethal concentrations (LC50) were calculated. It was observed that the LC50 values increased with a decrease in mean exposure times, for all metals and for both fish types. The 96-h LC50 values for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.006, 0.10, 0.46, 0.63, 0.83, 1.71, 1.53, and 5.71 mg/L for R. sumatrana and 0.038, 0.17, 1.06, 1.99, 15.62, 1.46, 6.76, and 23.91 mg/L for P. reticulata, respectively. The metal toxicity trend for R. sumatrana and P. reticulata from most to least toxic was Cu > Cd > Zn > Pb > Ni > Al > Fe > Mn and Cu > Cd > Zn > Fe > Pb > Al > Ni > Mn, respectively. Results indicated that Cu was the most toxic metal on both fish, and R. sumatrana was more sensitive than P. reticulata to all the eight metals.
    Matched MeSH terms: Environmental Monitoring; Iron/analysis; Iron/toxicity
  11. Jayaranee S, Sthaneshwar P, Sokkalingam S
    Pathology, 2009 Feb;41(2):178-82.
    PMID: 18972320 DOI: 10.1080/00313020802436840
    AIM: Hepcidin, a recently identified peptide, acts as a central regulator of iron metabolism. It is regarded as a factor regulating the uptake of dietary iron and its mobilisation from macrophages and hepatic stores. It is considered as a mediator of anaemia of inflammation. The aim of this study was to assess whether serum prohepcidin concentration is able to distinguish iron deficiency from anaemia of inflammation in patients with rheumatoid arthritis (RA).

    METHOD: Blood samples were obtained from 20 healthy blood donors, 30 RA patients who presented with anaemia and 30 patients who had pure iron deficiency anaemia (IDA). The samples were analysed for full blood count, iron, ferritin, transferrin, soluble transferrin receptor and prohepcidin.

    RESULTS: The mean prohepcidin level in the control subjects was 256 microg/L. The prohepcidin level was significantly lower in IDA patients (100 microg/L; p < 0.0001) but not significantly different from that of control in RA patients (250 microg/L; p > 0.05). Higher serum soluble transferrin receptor (sTfR) levels were observed in IDA (p < 0.0001) but not in RA compared with that of control (p > 0.05). RA patients were divided into iron depleted and iron repleted subgroups based on the ferritin level. Prohepcidin in the iron depleted group was significantly lower than the iron repleted group and the control (p < 0.0001) and higher levels were observed in the iron repleted group (p < 0.01). sTfR levels in the iron depleted group were significantly higher than the control and the iron repleted patients (p < 0.001). In the iron repleted group, sTfR level was not statistically different from that of control (p > 0.05).

    CONCLUSION: Serum prohepcidin is clearly reduced in uncomplicated iron deficiency anaemia. The reduced prohepcidin levels in the iron depleted RA patients suggests that there may be conflicting signals regulating hepcidin production in RA patients. In RA patients who have reduced hepcidin in the iron depleted group (ferritin <60 microg/L) where sTfR levels are increased suggests that these patients are iron deficient. Further studies with a larger cohort of patients are required to substantiate this point.

    Matched MeSH terms: Anemia, Iron-Deficiency/blood*; Anemia, Iron-Deficiency/diagnosis
  12. Zamanpoor M, Rosli R, Yazid MN, Husain Z, Nordin N, Thilakavathy K
    J Matern Fetal Neonatal Med, 2013 Jul;26(10):960-6.
    PMID: 23339569 DOI: 10.3109/14767058.2013.766710
    OBJECTIVE: To quantify circulating fetal DNA (fDNA) levels in the second and third trimesters of normal healthy pregnant individuals and pregnant women with the following clinical conditions: gestational diabetes mellitus (GDM), iron deficiency anemia and gestational hypertension (GHT).
    METHODS: The SRY gene located on the Y chromosome was used as a unique fetal marker. The fDNA was extracted from maternal plasma and the SRY gene concentrations were measured by quantitative real-time polymerase chain reaction (PCR) amplification using TaqMan dual labeled probe system.
    RESULTS: No significant differences were observed in the mean fDNA concentration between normal and GDM pregnancy samples (p > 0.05) and also between normal and anemic pregnancy samples (p > 0.05) in both trimesters, but significant differences were observed between the third trimester normal and GHT pregnancy samples (p = 0.001). GDM and iron deficiency anemia do not affect the levels of fDNA in maternal plasma while GHT significantly elevates the levels of fDNA in maternal plasma.
    CONCLUSIONS: Increased amount of circulating fDNA in maternal plasma could be used for early identification of adverse pregnancies. GDM and anemia do not affect the levels of fDNA in maternal plasma while GHT significantly elevates the levels of fDNA in maternal plasma. Hence, the elevated fDNA values could be used as a potential screening marker in pregnancies complicated with GHT but not with GDM and iron deficiency anemia.
    Matched MeSH terms: Anemia, Iron-Deficiency/blood*; Anemia, Iron-Deficiency/genetics
  13. Yajima I
    Nihon Eiseigaku Zasshi, 2017;72(1):49-54.
    PMID: 28154361 DOI: 10.1265/jjh.72.49
    Several experimental studies on hygiene have recently been performed and fieldwork studies are also important and essential tools. However, the implementation of experimental studies is insufficient compared with that of fieldwork studies on hygiene. Here, we show our well-balanced implementation of both fieldwork and experimental studies of toxic-element-mediated diseases including skin cancer and hearing loss. Since the pollution of drinking well water by toxic elements induces various diseases including skin cancer, we performed both fieldwork and experimental studies to determine the levels of toxic elements and the mechanisms behind the development of toxic-element-related diseases and to develop a novel remediation system. Our fieldwork studies in several countries including Bangladesh, Vietnam and Malaysia demonstrated that drinking well water was polluted with high concentrations of several toxic elements including arsenic, barium, iron and manganese. Our experimental studies using the data from our fieldwork studies demonstrated that these toxic elements caused skin cancer and hearing loss. Further experimental studies resulted in the development of a novel remediation system that adsorbs toxic elements from polluted drinking water. A well-balanced implementation of both fieldwork and experimental studies is important for the prediction, prevention and therapy of toxic-element-mediated diseases.
    Matched MeSH terms: Environmental Health*; Iron/adverse effects; Iron/analysis
  14. Abu MA, Borhan AS, Abdul Karim AK, Ahmad MF, Mahdy ZA
    Horm Mol Biol Clin Investig, 2020 Dec 14;42(1):49-56.
    PMID: 33781008 DOI: 10.1515/hmbci-2020-0034
    OBJECTIVES: To compare the effect of Iberet Folic® and Zincofer® on haemoglobin (Hb) and serum ferritin level; and its adverse effect.

    METHODS: This randomised controlled trial conducted from January 2018 until December 2018. Pregnant women below 34 weeks of gestation, with Hb concentration less than 11 g/dL and serum ferritin level less than 12 ug/L were randomised to receive either one tablet Zincofer® or one tablet Iberet Folate® daily for four weeks. Both groups were compared in terms of effect on Hb level, serum ferritin level, and other haematological indices adverse effect related to treatment, and treatment cost.

    RESULTS: Hundred and thirty patients were recruited in this study with 68 patients in Iberet Folic group and 62 patients in Zincofer group. The change in the Hb and serum ferritin level from baseline to day 30 did not differ significantly between treatment groups. The mean (±SD) change from baseline to day 30 was 2.15 (±0.59) g/dL in the Iberet Folic group, and 1.98 (±0.49) in the Zincofer (p value = 0.08). Mean serum ferritin at day 30 was 17.2 (±3.68) ug/L and 16.7 (±4.28) ug/L with 8.44 (±3.41) and 8.55 (±3.50) difference, respectively (p = 0.86). Adverse events were comparable in between groups, with p value >0.05. GI intolerance and constipation were among the common side effects, occurred in 34.6 and 29.2% cases, respectively.

    CONCLUSIONS: Zincofer® offers equivalent efficacy and side effect profile in comparison with Iberet Folic® for the treatment of iron deficiency anaemia (IDA) during pregnancy, but with lower cost.

    Matched MeSH terms: Anemia, Iron-Deficiency/blood; Anemia, Iron-Deficiency/drug therapy*
  15. Ambayya A, Su AT, Osman NH, Nik-Samsudin NR, Khalid K, Chang KM, et al.
    PLoS One, 2014;9(3):e91968.
    PMID: 24642526 DOI: 10.1371/journal.pone.0091968
    INTRODUCTION: Similar to other populations, full blood count reference (FBC) intervals in Malaysia are generally derived from non-Malaysian subjects. However, numerous studies have shown significant differences between and within populations supporting the need for population specific intervals.

    METHODS: Two thousand seven hundred twenty five apparently healthy adults comprising all ages, both genders and three principal races were recruited through voluntary participation. FBC was performed on two analysers, Sysmex XE-5000 and Unicel DxH 800, in addition to blood smears and haemoglobin analysis. Serum ferritin, soluble transferrin receptor and C-reactive protein assays were performed in selected subjects. All parameters of qualified subjects were tested for normality followed by determination of reference intervals, measures of central tendency and dispersion along with point estimates for each subgroup.

    RESULTS: Complete data was available in 2440 subjects of whom 56% (907 women and 469 men) were included in reference interval calculation. Compared to other populations there were significant differences for haemoglobin, red blood cell count, platelet count and haematocrit in Malaysians. There were differences between men and women, and between younger and older men; unlike in other populations, haemoglobin was similar in younger and older women. However ethnicity and smoking had little impact. 70% of anemia in premenopausal women, 24% in postmenopausal women and 20% of males is attributable to iron deficiency. There was excellent correlation between Sysmex XE-5000 and Unicel DxH 800.

    CONCLUSION: Our data confirms the importance of population specific haematological parameters and supports the need for local guidelines rather than adoption of generalised reference intervals and cut-offs.

    Matched MeSH terms: Anemia, Iron-Deficiency/blood*; Anemia, Iron-Deficiency/ethnology
  16. Bin Abas MR, Takruni IA, Abdullah Z, Tahir NM
    Talanta, 2002 Nov 12;58(5):883-90.
    PMID: 18968820
    A flow injection (FI) method with on-line preconcentration using a mini-column loaded with 8-hydroxyquinoline immobilized on controlled pore glass (CPG-8HQ) is described for the determination of trace metals by ion chromatography (IC) with pyridine-2-6-dicarboxylic acid (PDCA) as the eluent. Copper, cadmium, lead, zinc, nickel and iron were determined at ppb level after post-column derivatization with 4-(2-pyridylazo)-resorcinol (PAR). The detection limits (3sigma) for the FI/IC system were 8.27, 0.89, 0.09, 0.06, 0.09 and 0.07 g l(-1) for Pb(2+), Cd(2+), Cu(2+) Ni(2+), Zn(2+) and Fe(3+), respectively, using 5 ml sample volume. The method was applied to the analysis of Malaysian natural waters.
    Matched MeSH terms: Iron
  17. Leong LH, Kandaiya S, Seng NB
    Australas Phys Eng Sci Med, 2007 Jun;30(2):135-40.
    PMID: 17682403
    The oxidation of ferrous to ferric ions due to ionizing radiation has been used for chemical dosimetry since 1927. The introduction of metal indicator dye xylenol orange (XO) sensitises the measurement of ferric ion yield. A ferrous sulphate- agarose- xylenol orange (FAX) gel was prepared and the gel then exposed to dose ranging from 0.2 to 10 Gy using various high energy photon and electron beams from a linear accelerator. Some general characteristics of FAX such as energy dependence, optical density (OD)-dose relationship, reproducibility and auto-oxidation of ferrous ions were analysed. The radiation yield G of the gel was calculated for gels prepared in oxygen and in air and the values were 46.3 +/- 2.1 and 40.9 +/- 1.4 Fe3+ per 100 eV for photons respectively. However for stock gel which was kept for 5 days pre-irradiation the G value decreased to 36.6 +/- 1.1. The gel shows linearity in OD-dose relationship, energy independence and reproducibility over the dose range investigated. Auto-oxidation of ferrous ions resulted in optical density changes of less than 1.5% per day.
    Matched MeSH terms: Iron
  18. Choong YY, Norli I, Abdullah AZ, Yhaya MF
    Bioresour Technol, 2016 Jun;209:369-79.
    PMID: 27005788 DOI: 10.1016/j.biortech.2016.03.028
    This paper critically reviews the impacts of supplementing trace elements on the anaerobic digestion performance. The in-depth knowledge of trace elements as micronutrients and metalloenzyme components justifies trace element supplementation into the anaerobic digestion system. Most of the earlier studies reported that trace elements addition at (sub)optimum dosages had positive impacts mainly longer term on digester stability with greater organic matter degradation, low volatile fatty acids (VFA) concentration and higher biogas production. However, these positive impacts and element requirements are not fully understood, they are explained on a case to case basis because of the great variance of the anaerobic digestion operation. Iron (Fe), nickel (Ni) and cobalt (Co) are the most studied and desirable elements. The right combination of multi-elements supplementation can have greater positive impact. This measure is highly recommended, especially for the mono-digestion of micronutrient-deficient substrates. The future research should consider the aspect of trace element bioavailability.
    Matched MeSH terms: Iron
  19. Wong KT, Yoon Y, Snyder SA, Jang M
    Chemosphere, 2016 Jun;152:71-80.
    PMID: 26963238 DOI: 10.1016/j.chemosphere.2016.02.090
    Triethoxyphenylsilane (TEPS)-functionalized magnetic palm-based powdered activated carbon (MPPAC-TEPS) was prepared and characterized using various spectroscopic methods, and then tested for the removal of bisphenol A, carbamazepine, ibuprofen and clofibric acid. Magnetite film on MPPAC-TEPS was homogeneously coated on the outer surface of palm-based powdered activated carbon (PPAC) through a hydrothermal co-precipitation technique. Followed by silanization of phenyl-functionalized organosilane on MPPAC's magnetic film. As results, micro/mesopore surface area and volume increased without significant pore clogging and iron (Fe) dissolution under the acidic conditions was greatly decreased. The unique structural and chemical features of MPPAC-TEPS were found to be the main reasons for the enhanced adsorption rates and removal capacities of POPs. The presence of electrolytes and different pH values greatly affected the sorption efficiencies. The dominant sorption mechanism of POPs by MPPAC-TEPS was determined to be π-π interaction (physisorption), based on thermodynamic (ΔG°) and differential scanning calorimetry (DSC). Thermal regeneration at a low temperature (350 °C) was an effective method to desorb the retained POPs and enabled to reactivate MPPAC-TEPS with sustained sorption rates and capacities, whereas PPAC was largely exhausted. As a new type of sorbent for POPs, MPPAC-TEPS has operational advantages, such as magnetic separation and stable regeneration.
    Matched MeSH terms: Iron
  20. Lim PE, Kiu MY
    Environ Monit Assess, 1995 Apr;35(2):85-95.
    PMID: 24202270 DOI: 10.1007/BF00633708
    The Juru River flows through largely urbanized areas and is grossly polluted by domestic wastes and discharges from pig farms. Other than carrying highly polluting organic materials, these wastes are also contaminated with heavy metals. To ascertain the extent of heavy metal pollution in the river, total and non-residual concentrations of Cu, Pb, Zn, Mn and Fe in sediment samples collected along the river were determined. The results indicate that both the total and non-residual metal concentrations in sediments can successfully be used to identify heavy metal pollution sources. The speciation of Zn, Mn and Fe in the sediment samples were investigated using a sequential leaching technique which identifies the elements among six operationally defined host fractions: (1) exchangeable, (2) carbonate and surface-associated, (3) easily reducible, (4) moderately reducible, (5) bound to organic matter and sulphides and (6) residual. The results indicate that Zn is mainly associated with the reducible fractions. Zn and Fe found in the moderately reducible fraction are significantly correlated, indicating that iron oxides is the preferred host phase by Zn.
    Matched MeSH terms: Environmental Pollutants; Iron
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