Displaying publications 61 - 80 of 619 in total

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  1. Firouzi S, Haghighatdoost F
    Nutrition, 2018 02 06;51-52:104-113.
    PMID: 29626749 DOI: 10.1016/j.nut.2018.01.007
    OBJECTIVES: Recent studies have demonstrated promising results regarding possible improvements in renal function after prebiotic, probiotic, and synbiotic supplementation. The aim of this review was to demonstrate whether such supplementation will improve renal profile indexes including glomerular filtration rate (GFR), creatinine, blood urea nitrogen (BUN), uric acid (UA), and urea.

    METHOD: The meta-analysis included all studies that examined the effect of prebiotic, probiotic, and synbiotic supplements on one or more renal function parameters and had a control group. We searched July 1967 through to March 2016 MEDLINE, Scopus, and Google Scholar databases.

    RESULTS: Of 437 studies, 13 were eligible for inclusion in the meta-analysis. GFR levels tended to be reduced; whereas creatinine levels increased in the intervention group compared with the placebo group, both in a non-significant manner. The pooled effect on BUN demonstrated a significant decline compared with the placebo group (MD, -1.72 mmol/L; 95% confidence interval [CI], -2.93 to -0.51; P = 0.005). Urea significantly decreased after intervention (-0.46 mmol/L; 95% CI, -0.60 to -0.32; P <0.0001). The UA levels significantly increased in the intervention group compared with the placebo group (12.28 µmol/L; 95% CI, 0.85-23.71; P = 0.035).

    CONCLUSION: This study showed a significant increase in UA and a decrease in urea and BUN. The use of prebiotic, probiotic, and synbiotic supplements among those with compromised renal function or those at risk for renal failure should be limited until large-scale, well-designed randomized controlled trials prove the safety and efficacy of these supplements in improving renal function.

    Matched MeSH terms: Blood Urea Nitrogen
  2. Khor SM, Ng SL, Lim PE, Seng CE
    Environ Technol, 2011 Dec;33(15-16):1903-14.
    PMID: 22439579
    The objective of this study was to evaluate the effects ofNi(II) and Cr(VI) individually and in combination on the simultaneous removal of chemical oxygen demand (COD), nitrogen and metals under a sequencing batch reactor (SBR) operation. Three identical laboratory-scale SBRs were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in a ratio of 1:12:1:2:8 for a cycle time of 24 h until the steady state was achieved. Nickel(II) at increasing concentrations up to 35 mg/L was added to one of the reactors; Cr(VI) at increasing concentrations up to 25 mg/L was added to a second reactor; while a combination of Ni(II) and Cr(VI) in equal concentrations up to 10 mg/L was added to a third reactor. The results demonstrate that both Ni(II) and Cr(VI) exerted a more pronounced inhibitory effect on the removal of ammonia nitrogen (AN) than on COD removal. Synergistic and antagonistic inhibitory effects on the rates of COD and AN removal, respectively, were observed for the 50% Ni(II) and 50% Cr(VI) (w/w) mixture in the concentration range between 10 and 20 mg/L. The simultaneous presence of 50% Ni(II) and 50% Cr(VI) at a concentration of 20 mg/L resulted in system failure.
    Matched MeSH terms: Nitrogen/isolation & purification*
  3. Haslaniza, H., Maskat, M.Y., Wan Aida, W.M., Mamot, S.
    MyJurnal
    A study was carried out to determine the effect of enzyme concentration, temperature and incubation time of bromelain on nitrogen content (NC) and degree of hydrolysis (DH) of hydrolysate from cockle (Anadara granosa) meat wash water. Protein precipitation of cockle meat wash water was conducted at pH 4. The precipitate was then hydrolyzed using bromelain at concentrations of 0.5, 1.5 and 2.5% (enzyme/substrate). The best enzyme concentration was subsequently used to study the effect of incubation temperature at 30, 45 and 60°C. The best temperature was then used to determine the effect of incubation time at 0, 24 and 48 hours. Increasing bromelain concentration from 0 to 2.5% produced an increase in NC and DH. Similarly, increasing the incubation time from 0 to 48 hours also increased the value of NC and DH. However, while the increasing of incubation temperature from 30 to 60°C produced an increase in NC, no significant difference was observed for DH.
    Matched MeSH terms: Nitrogen
  4. Lee KK, Kassim AM, Lee HK
    Water Sci Technol, 2004;50(5):73-7.
    PMID: 15497832
    White-rot fungi, namely Coriolus versicolor and Schizophyllum commune, were studied for the biodecolorization of textile dyeing effluent in shaker-flask experiments. The results showed that C. versicolor was able to achieve 68% color removal after 5 days of treatment while that of S. commune was 88% in 9 days. Both fungi achieved the above results in non-sterile condition with diammonium hydrogen phosphate as the nutrient supplement. On the other hand, the best COD removal of 80% was obtained with C. versicolor in 9 days in sterile effluent with yeast extract as nutrient supplement, while S. commune was able to remove 85% COD within 8 days in non-sterile textile effluent supplemented with diammonium hydrogen phosphate.
    Matched MeSH terms: Nitrogen/pharmacology*; Nitrogen/chemistry
  5. Lim PE, Tay MG, Mak KY, Mohamed N
    Sci Total Environ, 2003 Jan 01;301(1-3):13-21.
    PMID: 12493181
    The objective of this study is to investigate the respective effects of Zn, Pb and Cd as well as the combined effect of Zn, Pb, Cd and Cu on the removal of nitrogen and oxygen demand in constructed wetlands. Four laboratory-scale gravel-filled subsurface-flow constructed wetland units planted with cattails (Typha latifolia) were operated outdoors and fed with primary-treated domestic wastewater at a constant flow rate of 25 ml/min. After 6 months, three of the wetland units were fed with the same type of wastewater spiked with Zn(II), Pb(II) and Cd(II), respectively, at 20, 5 and 1 mg/l for a further 9 months. The remaining unit was fed with the same type of wastewater spiked with a combination of Zn(II), Pb(II), Cd(II) and Cu(II) at concentrations of 10, 2.5, 0.5 and 5 mg/l, respectively, over the same period. The chemical oxygen demand (COD) and ammoniacal nitrogen (AN) concentrations were monitored at the inlet, outlet and three additional locations along the length of the wetland units to assess the performance of the wetland units at various metal loadings. At the end of the study, all cattail plants were harvested for the determination of total Kjeldahl nitrogen and metal concentrations. The results showed that the COD removal efficiency was practically independent of increasing metal loading or a combination of metal loadings during the duration of the study. In contrast, the AN removal efficiency deteriorated progressively with increasing metal loading. The relative effect of the heavy metals was found to increase in the order: Znnitrogen uptake by cattail plants as indicated by lower nitrogen uptake rates in comparison to rates recorded in wetland systems treating domestic wastewater only.
    Matched MeSH terms: Nitrogen/isolation & purification*
  6. Tie HO, Che Man H, Koyama M, Syukri F, Md Yusoff F, Toda T, et al.
    Waste Manag, 2023 Jul 01;166:194-202.
    PMID: 37178588 DOI: 10.1016/j.wasman.2023.04.046
    A modified outdoor large-scale nutrient recycling system was developed to compost organic sludge and aimed to recover clean nitrogen for the cultivation of high-value-added microalgae. This study investigated the effect of calcium hydroxide addition on enhancing NH3 recovery in a pilot-scale reactor self-heated by metabolic heat of microorganisms during thermophilic composting of dewatered cow dung. 350 kg-ww of compost was prepared at the ratio of 5: 14: 1 (dewatered cowdung: rice husk: compost-seed) in a 4 m3 cylindrical rotary drum composting reactor for 14 days of aerated composting. High compost temperature up to 67 °C was observed from day 1 of composting, proving that thermophilic composting was achieved through the self-heating process. The temperature of compost increases as microbial activity increases and temperature decreases as organic matter decreases. The high CO2 evolution rate on day 0-2 (0.02-0.08 mol/min) indicated that microorganisms are most active in degrading organic matter. The increasing conversion of carbon demonstrated that organic carbon was degraded by microbial activity and emitted as CO2. The nitrogen mass balance revealed that adding calcium hydroxide to the compost and increasing the aeration rate on day 3 volatilized 9.83 % of the remaining ammonium ions in the compost, thereby improving the ammonia recovery. Moreover, Geobacillus was found to be the most dominant bacteria under elevated temperature that functions in the hydrolysis of non-dissolved nitrogen for better NH3 recovery. The presented results show that by thermophilic composting 1 ton-ds of dewatered cowdung for NH3 recovery, up to 11.54 kg-ds of microalgae can be produced.
    Matched MeSH terms: Nitrogen/analysis
  7. Ujang Z, Salim MR, Khor SL
    Water Sci Technol, 2002;46(9):193-200.
    PMID: 12448469
    A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 microm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.
    Matched MeSH terms: Nitrogen/isolation & purification
  8. Hamdan R, Mara DD
    Water Sci Technol, 2011;63(5):841-4.
    PMID: 21411931 DOI: 10.2166/wst.2011.102
    Rock filters are an established technology for polishing waste stabilization pond effluents. However, they rapidly become anoxic and consequently do not remove ammonium-nitrogen. Horizontal-flow aerated rock filters (HFARF), developed to permit nitrification and hence ammonium-N removal, were compared with a novel vertical-flow aerated rock filter (VFARF). There were no differences in the removals of BOD5, TSS and TKN, but the VFARF consistently produced effluents with lower ammonium-N concentrations (<0.3 mg N/L) than the HFARF (0.8-1.5 mg N/L) and higher nitrate-N concentrations (24-29 mg N/L vs. 17-24 mg N/L).
    Matched MeSH terms: Nitrogen/chemistry*
  9. Nagymihály M, Vásarhelyi BM, Barrière Q, Chong TM, Bálint B, Bihari P, et al.
    Stand Genomic Sci, 2017;12:75.
    PMID: 29255570 DOI: 10.1186/s40793-017-0298-3
    Strain CCMM B554, also known as FSM-MA, is a soil dwelling and nodule forming, nitrogen-fixing bacterium isolated from the nodules of the legume Medicago arborea L. in the Maamora Forest, Morocco. The strain forms effective nitrogen fixing nodules on species of the Medicago, Melilotus and Trigonella genera and is exceptional because it is a highly effective symbiotic partner of the two most widely used accessions, A17 and R108, of the model legume Medicago truncatula Gaertn. Based on 16S rRNA gene sequence, multilocus sequence and average nucleotide identity analyses, FSM-MA is identified as a new Ensifer meliloti strain. The genome is 6,70 Mbp and is comprised of the chromosome (3,64 Mbp) harboring 3574 predicted genes and two megaplasmids, pSymA (1,42 Mbp) and pSymB (1,64 Mbp) with respectively 1481 and 1595 predicted genes. The average GC content of the genome is 61.93%. The FSM-MA genome structure is highly similar and co-linear to other E. meliloti strains in the chromosome and the pSymB megaplasmid while, in contrast, it shows high variability in the pSymA plasmid. The large number of strain-specific sequences in pSymA as well as strain-specific genes on pSymB involved in the biosynthesis of the lipopolysaccharide and capsular polysaccharide surface polysaccharides may encode novel symbiotic functions explaining the high symbiotic performance of FSM-MA.
    Matched MeSH terms: Nitrogen
  10. Gou Z, Zheng H, He Z, Su Y, Chen S, Chen H, et al.
    Environ Pollut, 2023 Jan 15;317:120790.
    PMID: 36460190 DOI: 10.1016/j.envpol.2022.120790
    This study aims to investigate the positive effects of the combined use of Enterobacter cloacae and biochar on improving nitrogen (N) utilization. The greenhouse pots experimental results showed the synergy of biochar and E. cloacae increased soil total N content and plant N uptake by 33.54% and 15.1%, respectively. Soil nitrogenase (NIT) activity increased by 253.02%. Ammonia monooxygenase (AMO) and nitrate reductase (NR) activity associated with nitrification and denitrification decreased by 10.94% and 29.09%, respectively. The relative abundance of N fixing microorganisms like Burkholderia and Bradyrhizobium significantly increased. Sphingomonas and Ottowia, two bacteria involved in the nitrification and denitrification processes, were found to be in lower numbers. The E. cloacae's ability to fix N2 and promote the growth of plants allow the retention of N in soil and make more N available for plant development. Biochar served as a reservoir of N for plants by adsorbing N from the soil and providing a shelter for E. cloacae. Thus, biochar and E. cloacae form a synergy for the management of agricultural N and the mitigation of negative impacts of pollution caused by excessive use of N fertilizer.
    Matched MeSH terms: Nitrogen; Nitrogen-Fixing Bacteria*
  11. MacKenzie AR, Langford B, Pugh TA, Robinson N, Misztal PK, Heard DE, et al.
    Philos Trans R Soc Lond B Biol Sci, 2011 Nov 27;366(1582):3177-95.
    PMID: 22006961 DOI: 10.1098/rstb.2011.0053
    We report measurements of atmospheric composition over a tropical rainforest and over a nearby oil palm plantation in Sabah, Borneo. The primary vegetation in each of the two landscapes emits very different amounts and kinds of volatile organic compounds (VOCs), resulting in distinctive VOC fingerprints in the atmospheric boundary layer for both landscapes. VOCs over the Borneo rainforest are dominated by isoprene and its oxidation products, with a significant additional contribution from monoterpenes. Rather than consuming the main atmospheric oxidant, OH, these high concentrations of VOCs appear to maintain OH, as has been observed previously over Amazonia. The boundary-layer characteristics and mixing ratios of VOCs observed over the Borneo rainforest are different to those measured previously over Amazonia. Compared with the Bornean rainforest, air over the oil palm plantation contains much more isoprene, monoterpenes are relatively less important, and the flower scent, estragole, is prominent. Concentrations of nitrogen oxides are greater above the agro-industrial oil palm landscape than over the rainforest, and this leads to changes in some secondary pollutant mixing ratios (but not, currently, differences in ozone). Secondary organic aerosol over both landscapes shows a significant contribution from isoprene. Primary biological aerosol dominates the super-micrometre aerosol over the rainforest and is likely to be sensitive to land-use change, since the fungal source of the bioaerosol is closely linked to above-ground biodiversity.
    Matched MeSH terms: Nitrogen Oxides/chemistry
  12. Husain NN, Hairon SM, Zain RM, Bakar M, Bee TG, Ismail MS
    Oman Med J, 2020 Mar;35(2):e108.
    PMID: 32257417 DOI: 10.5001/omj.2020.26
    Objectives: Despite being recognized worldwide as an alternative therapy in treating various chronic diseases and pain, the mechanism of wet cupping is still not well understood. The purpose of this study was to evaluate fasting blood sugar (FBS), renal function parameters, and endothelial function changes following wet cupping in healthy individuals.

    Methods: We conducted a single-arm intervention study at the Clinical Lab of Community Medicine, Universiti Sains Malaysia, and included 31 healthy individuals aged between 30 and 60 years old. Wet cupping therapy was performed at five treatment points at the beginning of the study and repeated after three months. Health outcomes at baseline, one, three, and four months were assessed for FBS, renal function parameters (urea, creatinine, and uric acid), systolic blood pressure (SBP), and von Willebrand factor (vWF).

    Results: Forty-five percent of participants were female, and the mean age of study participants was 44.9±6.4 years. Wet cupping therapy significantly reduced FBS, serum urea, and serum creatinine at one, three, and four months compared with baseline values. Serum uric acid and SBP showed a significant reduction at one and four months compared with baseline. The vWF (a measure of endothelial function) had a 4.0% reduction at four months compared to baseline, with a mean difference of 5.3 (95% confidence interval (CI): 2.20 = 8.55; p = 0.002).

    Conclusions: This study provides preliminary support that repeated wet cupping therapy enhances body health status; thus, it could be an effective complementary medicine in disease prevention.

    Matched MeSH terms: Blood Urea Nitrogen
  13. Lee CW, Bong CW, Hii YS
    Appl Environ Microbiol, 2009 Dec;75(24):7594-601.
    PMID: 19820145 DOI: 10.1128/AEM.01227-09
    We investigated the temporal variation of bacterial production, respiration, and growth efficiency in the tropical coastal waters of Peninsular Malaysia. We selected five stations including two estuaries and three coastal water stations. The temperature was relatively stable (averaging around 29.5 degrees C), whereas salinity was more variable in the estuaries. We also measured dissolved organic carbon and nitrogen (DOC and DON, respectively) concentrations. DOC generally ranged from 100 to 900 microM, whereas DON ranged from 0 to 32 microM. Bacterial respiration ranged from 0.5 to 3.2 microM O2 h(-1), whereas bacterial production ranged from 0.05 to 0.51 microM C h(-1). Bacterial growth efficiency was calculated as bacterial production/(bacterial production + respiration), and ranged from 0.02 to 0.40. Multiple correlation analyses revealed that bacterial production was dependent upon primary production (r2 = 0.169, df = 31, and P < 0.02) whereas bacterial respiration was dependent upon both substrate quality (i.e., DOC/DON ratio) (r2 = 0.137, df = 32, and P = 0.03) and temperature (r2 = 0.113, df = 36, and P = 0.04). Substrate quality was the most important factor (r2 = 0.119, df = 33, and P = 0.04) for the regulation of bacterial growth efficiency. Using bacterial growth efficiency values, the average bacterial carbon demand calculated was from 5.30 to 11.28 microM C h(-1). When the bacterial carbon demand was compared with primary productivity, we found that net heterotrophy was established at only two stations. The ratio of bacterial carbon demand to net primary production correlated significantly with bacterial growth efficiency (r2 = 0.341, df = 35, and P < 0.001). From nonlinear regression analysis, we found that net heterotrophy was established when bacterial growth efficiency was <0.08. Our study showed the extent of net heterotrophy in these waters and illustrated the importance of heterotrophic microbial processes in coastal aquatic food webs.
    Matched MeSH terms: Nitrogen/analysis
  14. Hussain H, Yusoff MK, Ramli MF, Abd Latif P, Juahir H, Zawawi MA
    Pak J Biol Sci, 2013 Nov 15;16(22):1524-30.
    PMID: 24511695
    Nitrate-nitrogen leaching from agricultural areas is a major cause for groundwater pollution. Polluted groundwater with high levels of nitrate is hazardous and cause adverse health effects. Human consumption of water with elevated levels of NO3-N has been linked to the infant disorder methemoglobinemia and also to non-Hodgkin's disease lymphoma in adults. This research aims to study the temporal patterns and source apportionment of nitrate-nitrogen leaching in a paddy soil at Ladang Merdeka Ismail Mulong in Kelantan, Malaysia. The complex data matrix (128 x 16) of nitrate-nitrogen parameters was subjected to multivariate analysis mainly Principal Component Analysis (PCA) and Discriminant Analysis (DA). PCA extracted four principal components from this data set which explained 86.4% of the total variance. The most important contributors were soil physical properties confirmed using Alyuda Forecaster software (R2 = 0.98). Discriminant analysis was used to evaluate the temporal variation in soil nitrate-nitrogen on leaching process. Discriminant analysis gave four parameters (hydraulic head, evapotranspiration, rainfall and temperature) contributing more than 98% correct assignments in temporal analysis. DA allowed reduction in dimensionality of the large data set which defines the four operating parameters most efficient and economical to be monitored for temporal variations. This knowledge is important so as to protect the precious groundwater from contamination with nitrate.
    Matched MeSH terms: Nitrogen/analysis*
  15. Al-Khadher SAA, Abdul Kadir A, Al-Gheethi AAS, Azhari NW
    Environ Sci Pollut Res Int, 2021 Dec;28(46):65513-65524.
    PMID: 34322791 DOI: 10.1007/s11356-021-15011-0
    The current work aimed to study the physical, chemical and biological properties of food wastes generated from small and medium industries by using Takakura composting methods. Composting method was referred as indigenous compost (IC) and commercial compost (CC) reactors. The reactors were operated at 44 °C, pH (6 to 8.5) and 40 to 55 % of moisture for 22 weeks in closed environment using a carpet around the basket to avoid external disturbance. The results revealed that the total Kjeldahl nitrogen (TKN), total phosphorus (TP) and potassium (K) in the IC reactors were 6300, 10.57 and 726.07 ppm, respectively, while 8400, 15.45 and 727.81 ppm, respectively, in the CC reactors. Moreover, both IC and CC has Cd2+, Cr2+, Cu2+, Pb2+, Ni2+ and Zn2+ concentrations within the compost legislation standard (CLS). The findings of this study indicated that the composting method could be used as an alternative food waste management in small and medium industry and the Takakura composting method is suitable for food waste composting.
    Matched MeSH terms: Nitrogen/analysis
  16. AIDA NADIA A.RAMLEE, WAN ZALIHA WAN SEMBOK
    MyJurnal
    Fresh-cut pineapple has experienced an increase in demand due to its great health benefits and is rich in vitamins A, B and C. Moreover, pineapple is known as a source of the enzyme bromelain, which has therapeutic applications, such as reducing inflammation, improving digestion and treating osteoarthritis. However, bromelain generally affects the pineapple’s flavour and is less preferred by consumers due to the uncomfortable prickling and tingling sensations it brings. In the present study, two types of gases and their combination, nitrogen (N2) and carbon dioxide (CO2), were used to evaluate their impacts on reducing the tingling and prickling sensations, as well as maintaining the postharvest qualities of fresh-cut pineapple stored at 5°C for 12 days. The parameters being evaluated were the bromelain enzyme activity, flesh colour, ascorbic acid concentration, flesh firmness, soluble solids concentration (SSC), titratable acidity (TA) and sensory evaluation. No significant differences were recorded for all parameters tested. Based on the sensory evaluations, all the attributes, such as colour, aroma, texture, sweetness, sourness, tingling and prickling sensations, and overall acceptance were not affected by the different gases application. Even though no apparent effect was observed, the 30 panellists preferred the aforementioned attributes, except sourness. In conclusion, the fumigation treatments with N2 and CO2 gases were not effective in reducing the tingling and prickling sensations of pineapples cv. Morris.
    Matched MeSH terms: Nitrogen
  17. Saswati, Adão P, Majumder S, Dash SP, Roy S, Kuznetsov ML, et al.
    Dalton Trans, 2018 Aug 21;47(33):11358-11374.
    PMID: 30059099 DOI: 10.1039/c8dt01668b
    The synthesis and characterization of an oxidovanadium(iv) [VIVO(L)(acac)] (1) and of two dioxidovanadium(v) [VVO2(L')] (2) and [VVO2(L)] (2a) complexes of the Schiff base formed from the reaction of 4-(p-fluorophenyl) thiosemicarbazone with pyridine-2-aldehyde (HL) are described. The oxidovanadium(iv) species [VIVO(L)(acac)] (1) was synthesized by the reaction of VIVO(acac)2 with the thiosemicarbazone HL in refluxing ethanol. The recrystallization of [VIVO(L)(acac)] (1) in DMF, CH3CN or EtOH gave the same product i.e. the dioxidovanadium(v) complex [VVO2(L)] (2a); however, upon recrystallization of 1 in DMSO a distinct compound [VVO2(L')] (2) was formed, wherein the original ligand L- is transformed to a rearranged one, L'-. In the presence of DMSO the ligand in complex 1 is found to undergo methylation at the carbon centre attached to imine nitrogen (aldimine) and transformed to the corresponding VVO2-species through in situ reaction. The synthesized HL and the metal complexes were characterized by elemental analysis, IR, UV-Vis, NMR and EPR spectroscopy. The molecular structure of [VVO2(L')] (2) was determined by single crystal X-ray crystallography. The methylation of various other ligands and complexes prepared from different vanadium precursors under similar reaction conditions was also attempted and it was confirmed that the imine methylation observed is both ligand and metal precursor specific. Complexes 1 and 2 show in vitro insulin-like activity against insulin responsive L6 myoblast cells, higher than VIVO(acac)2, with complex 1 being more potent. In addition, the in vitro cytotoxicity studies of HL, and of complexes 1 and 2 against the MCF-7 and Vero cell lines were also done. The ligand is not cytotoxic and complex 2 is significantly more cytotoxic than 1. DAPI staining experiments indicate that an increase in the time of incubation and an increase of concentration of the complexes lead to the increase in cell death.
    Matched MeSH terms: Nitrogen
  18. Md Yusof EN, S A Ravoof TB, Tiekink ER, Veerakumarasivam A, Crouse KA, Mohamed Tahir MI, et al.
    Int J Mol Sci, 2015 May 15;16(5):11034-54.
    PMID: 25988384 DOI: 10.3390/ijms160511034
    Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC) with 2-methoxybenzaldehyde (2MB) and 3-methoxybenzaldehyde (3MB). The ligands were reacted separately with acetates of Cu(II), Ni(II) and Zn(II) yielding 1:2 (metal:ligand) complexes. The metal complexes formed were expected to have a general formula of [M(NS)2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1) and S2M3MBH (2) were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) breast cancer cell lines. Only the Cu(II) complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II) complexes have a strong DNA binding affinity.
    Matched MeSH terms: Nitrogen/chemistry*
  19. Chah, C.K., Ravoof, T.B.S.A., Veerakumarasivam, A.
    MyJurnal
    A novel nitrogen-sulphur macrocyclic Schiff base, 4,11,20,27-tetrathioxo3,12,19,28-tetrathia-5,6,9,10,21,22,25,26-octaazatricyclo[28.2.2.214,17]hexatriaconta 1(33),6,8,14(36),15,17(35),22,24,30(34),31-decaene-2,13,18,29-tetraone (TGSB) derived from terephthaloyl-bis-dithiocarbazate (TDTC) and glyoxal (ethane-1,2-dione) is synthesised via condensation. Metal complexes are formed by reacting the Schiff base with various metal salts such as Ru(III), Mo(V), Cd(II), Zn(II) and Cu(II). The complexes are expected to have a general formula of M2L or M3L with a square planar or square pyramidal geometry. These compounds were characterised by various physicochemical and spectroscopic techniques. From the data, it is concluded that the azomethine nitrogen atom and the thiolate sulphur atom from the ligand are bonded to the metal ion. In the IR spectra of the complexes, the presence of the C=N band in the region of 1600 cm-1 indicates the successful formation of the Schiff base. The structures of the Schiff base and metal complexes are confirmed via FT-IR, GC-MS and NMR spectroscopic analysis. The magnetic susceptibility measurements, electronic spectral data and molar conductivity analysis support the desired geometry of the complexes. The Schiff base and its metal complexes are evaluated for their biological activities against the invasive human bladder carcinoma cell line (EJ-28) and the minimuminvasive human bladder carcinoma cell line (RT-112). The RuTGSB and CdTGSB complexes showed selective activity against RT-112.
    Matched MeSH terms: Nitrogen
  20. Sim DHH, Tan IAW, Lim LLP, Lau ET, Hameed BH
    Waste Manag, 2024 Jan 01;173:51-61.
    PMID: 37977096 DOI: 10.1016/j.wasman.2023.11.006
    Nutrient leaching and volatilization cause environmental pollution, thus the pursuit of developing controlled-release fertilizer formulation is necessary. Biochar-based fertilizer exhibits slow-release characteristic, however the nutrient release mechanism needs to be improved. To overcome this limitation, the approach of applying encapsulation technology with biochar-based fertilizer has been implemented in this study. Black peppercorn waste was used to synthesize urea-impregnated biochar (UIB). Central composite design was used to investigate the effects of pyrolysis temperature, residence time and urea:biochar ratio on nitrogen content of UIB. The optimum condition to synthesize UIB was at 400 °C pyrolysis temperature, 120 min residence time and 0.6:1 urea:biochar ratio, which resulted in 16.07% nitrogen content. The tapioca starch/palm oil (PO) biofilm formulated using 8 g of tapioca starch and 0.12 µL of PO was coated on the UIB to produce encapsulated urea-impregnated biochar (EUIB). The UIB and EUIB pellets achieved complete release of nitrogen in water after 90 min and 330 min, respectively. The nutrient release mechanism of UIB and EUIB was best described by the Higuchi model and Korsmeyer-Peppas model, respectively. The improvement of water retention ratio of UIB and EUIB pellets was more significant in sandy-textural soil as compared to clayey-textural soil. The EUIB derived from peppercorn waste has the potential to be utilized as a sustainable controlled-release fertilizer for agriculture.
    Matched MeSH terms: Nitrogen/analysis
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