Displaying publications 41 - 60 of 619 in total

Abstract:
Sort:
  1. An efficient oxic-anoxic process for treating low COD/N tropical wastewater: Startup, optimization and nitrifying community structure
    How SW, Nittami T, Ngoh GC, Curtis TP, Chua ASM
    Chemosphere, 2020 Nov;259:127444.
    PMID: 32640378 DOI: 10.1016/j.chemosphere.2020.127444
    In this study, we assessed and optimized a low-dissolved-oxygen oxic-anoxic (low-DO OA) process to achieve a low-cost and sustainable solution for wastewater treatment systems in the developing tropical countries treating low chemical oxygen demand-to-nitrogen ratio (COD/N) wastewater. The low-DO OA process attained complete ammonia removal and the effluent nitrate nitrogen (NO3-N) was below 0.3 mg/L. The recommended hydraulic retention time and sludge retention time (SRT) were 16 h and 20 days, respectively. The 16S rRNA sequencing data revealed that long SRT (20 days) encouraged the growth of nitrite-oxidizing bacteria (NOB) affiliated with "Candidatus Nitrospira defluvii". Comammox made up 10-20% of the Nitrospira community. NOB and comammox related to Nitrospira were enriched at long SRT (20 days) to achieve good low-DO nitrification performance. The low-DO OA process was efficient and has simpler design than conventional processes, which are keys for sustainable wastewater treatment systems in the developing countries treating low COD/N wastewater.
    Matched MeSH terms: Nitrogen
  2. Analisis prestasi nutrien pengkomposan sisa industri sawit bagi skala industri dalam tempoh tiga tahun
    Asis T, Zahrim AY, Assis K
    Sains Malaysiana, 2017;46:1201-1210.
    Pengkomposan tandan buah kosong (EFB) dan sisa efluen kilang (POME) merupakan pendekatan lestari bagi menukarkan EFB dan POME kepada baja kompos. Pengkomposan adalah satu proses biologi yang memerlukan pengawalan yang optimum agar nutrien yang terhasil adalah tinggi dan stabil. Cabaran utama yang dihadapi oleh industri kompos ialah untuk menghasilkan kompos yang bernutrien tinggi dan stabil. Objektif kajian ini ialah untuk menganalisis prestasi jangka panjang bagi loji kompos terpilih melalui kandungan nutrien kompos yang dihasilkan. Penyelidikan ini mengkaji prestasi tiga tahun bagi empat loji kompos di Malaysia iaitu loji kompos Merotai, loji kompos Binuang, loji kompos Tanah Merah dan loji kompos Elphil. Prestasi kandungan nutrien yang diambil kira termasuklah nitrogen, kalium, nisbah karbon kepada nitrogen, kandungan kelembapan dan agregat kompos. Sebanyak 1,465 set data nutrien dianalisis secara deskriptif. Secara keseluruhannya, prestasi kandungan nutrien kesemua loji kompos yang dikaji berjaya memenuhi keperluan minimum industri sawit. Namun terdapat kes kompos yang dihasilkan mengandungi nutrien kalium yang tidak mencapai keperluan minimum industri dan kandungan kelembapan kompos yang tinggi. Kesimpulannya, masih terdapat ruang untuk penambahbaikan dalam proses pengkomposan agar kompos yang dihasilkan mengandungi nutrien yang stabil dan memenuhi keperluan minimum industri
    Matched MeSH terms: Nitrogen
  3. Analysis of core protein clusters identifies candidate variable sites conferring metronidazole resistance in Helicobacter pylori
    Chua EG, Debowski AW, Webberley KM, Peters F, Lamichhane B, Loke MF, et al.
    Gastroenterol Rep (Oxf), 2019 Feb;7(1):42-49.
    PMID: 30792865 DOI: 10.1093/gastro/goy048
    Background: Metronidazole is one of the first-line drugs of choice in the standard triple therapy used to eradicate Helicobacter pylori infection. Hence, the global emergence of metronidazole resistance in Hp poses a major challenge to health professionals. Inactivation of RdxA is known to be a major mechanism of conferring metronidazole resistance in H. pylori. However, metronidazole resistance can also arise in H. pylori strains expressing functional RdxA protein, suggesting that there are other mechanisms that may confer resistance to this drug.

    Methods: We performed whole-genome sequencing on 121 H. pylori clinical strains, among which 73 were metronidazole-resistant. Sequence-alignment analysis of core protein clusters derived from clinical strains containing full-length RdxA was performed. Variable sites in each alignment were statistically compared between the resistant and susceptible groups to determine candidate genes along with their respective amino-acid changes that may account for the development of metronidazole resistance in H. pylori.

    Results: Resistance due to RdxA truncation was identified in 34% of metronidazole-resistant strains. Analysis of core protein clusters derived from the remaining 48 metronidazole-resistant strains and 48 metronidazole-susceptible identified four variable sites significantly associated with metronidazole resistance. These sites included R16H/C in RdxA, D85N in the inner-membrane protein RclC (HP0565), V265I in a biotin carboxylase protein (HP0370) and A51V/T in a putative threonylcarbamoyl-AMP synthase (HP0918).

    Conclusions: Our approach identified new potential mechanisms for metronidazole resistance in H. pylori that merit further investigation.

    Matched MeSH terms: Carbon-Nitrogen Ligases
  4. Analysis on the changes of fertilization intensity and efficiency in China's grain production from 1980 to 2019
    Liu Q, Wu TY, Tu W, Pu L
    J Sci Food Agric, 2023 Jan 30;103(2):908-916.
    PMID: 36067269 DOI: 10.1002/jsfa.12202
    BACKGROUND: Relieving serious non-point source pollution of nitrogen (N), phosphorus (P), and potassium (K) is an urgent task in China. It is necessary to explore the changing characteristics of chemical fertilization intensity (FI) and efficiency to provide references. A new method of 'relative productivity proportion weight', which was simpler than data envelope analysis, was proposed to construct models of fertilizer allocation efficiency (FAE) and chemical fertilizer integrated efficiency (FIE) by considering NPK multi-inputs and the grain output scale, respectively.

    RESULTS: During 1980-2014, the FIs of NPK chemical fertilizers in China showed a significant growing trend. After reaching the highest value of 339 kg ha-1 in 2014, FIs were reduced to 303 kg ha-1 in 2019, higher than the 225 kg ha-1 maximum safe usage internationally recognized. Meanwhile, the pattern of change of FAE was one of 'decreasing to increasing', with values of 1 in 1980, 0.66 in 2003, and 0.80 in 2019. FIE basically showed an increasing trend, which could be divided into three stages: the first stage of low efficiency during 1980-2009, the second stage of medium efficiency after 2010, and the third stage of high efficiency after 2018.

    CONCLUSION: From 1980 until 2019, a reduction of FAE from 1 to 0.80 with an average of 0.75 was observed in China. FIE was found between 0.65 and 0.85 and had the potential of upgrading by 15-35%. Therefore, China needs to improve the fertilizer use efficiency in order to strive for negative growth of chemical fertilizer intensity and ecological agriculture construction. © 2022 Society of Chemical Industry.

    Matched MeSH terms: Nitrogen/analysis
  5. Anammox process for aquaculture wastewater treatment: operational condition, mechanism, and future prospective
    Ismail IN, Taufik M, Umor NA, Norulhuda MR, Zulkarnaini Z, Ismail S
    Water Sci Technol, 2022 Dec;86(12):3093-3112.
    PMID: 36579872 DOI: 10.2166/wst.2022.403
    Treatment of ammonia- and nitrate-rich wastewater, such as that generated in the aquaculture industry, is important to prevent environmental pollution. The anaerobic ammonium oxidation (anammox) process has been reported as a great alternative in reducing ammoniacal nitrogen concentration in aquaculture wastewater treatment compared to conventional treatment systems. This paper will highlight the impact of the anammox process on aquaculture wastewater, particularly in the regulation of ammonia and nitrogen compounds. The state of the art for anammox treatment systems is discussed in comparison to other available treatment methods. While the anammox process is viable for the treatment of aquaculture wastewater, the efficiency of nitrogen removal could be further improved through the proper use of anammox bacteria, operating conditions, and microbial diversity. In conclusion, a new model of the anammox process is proposed in this review.
    Matched MeSH terms: Nitrogen
  6. Ancillary palm oil fuel ash (POFA) in sequencing batch reactor for enhancing recalcitrant pollutants removal from domestic wastewater
    Lyn CW, Bashir MJ, Wong LY, Lim JW, Sethupathi S, Ng CA
    Chemosphere, 2020 Nov 25.
    PMID: 33276996 DOI: 10.1016/j.chemosphere.2020.129050
    Domestic wastewater has been generated massively along with rapid growth of population and economic. Biological treatment using sequencing batch reactor (SBR) augmented with palm oil fuel ash (POFA) was investigated for the first time. The performance of POFA in enhancing biological treatment of wastewater has not been tested. The porosity property of POFA can improve SBR efficiency by promoting growth of mixed liquor suspended solids (MLSS) and formation of larger flocs for settling and facilitating attachment of microorganisms and pollutants onto POFA surfaces. The properties of POFA were tested to identify morphological properties, particle size, surface area, chemical compositions. Four SBRs, namely SBR1, SBR2, SBR3 and SBR4 were provided with aeration rate of 1, 2, 3 and 4 L/min, respectively. Each reactor was augmented with different dosages of POFA. Optimum aeration rate and POFA concentration were identified by the performance of SBRs in removing chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N) and colour from domestic wastewater. The results showed the most efficient COD (97.8%), NH3-N (99.4%) and colour (98.8%) removals were achieved at optimum POFA concentration of 4 g/L in SBR and aeration rate of 1 L/min. The study also found that higher aeration rate would contribute to the smaller specific size of flocs and decrease the pollutant removal efficiency.
    Matched MeSH terms: Nitrogen
  7. Anggaran dan ciri fizikokimia sisa buangan makanan di Bandar Baru Bangi
    Leow KT, Aminah Abdullah, Mushrifah Idris
    Sains Malaysiana, 2010;39.
    Anggaran kuantiti dan pencirian fizikokimia sisa buangan makanan adalah pra-keperluan untuk mengoptimumkan proses pengkomposan. Satu tinjauan untuk menganggar jumlah sisa buangan makanan yang dijana oleh sektor komersial (n=10) dan isi rumah (n=50) di Bandar Baru Bangi telah dilakukan. Kehadiran komponen sisa nasi, sisa berasaskan daging, ikan, sayur-sayuran dan buah-buahan dan sisa buangan makanan basah yang lain juga diperiksa. Ciri fizikokimia sisa buangan makanan juga dianalisis. Jumlah sisa buangan makanan yang dijana di Bandar Baru Bangi dianggarkan sebanyak 11.41 MT sehari. Sektor isi rumah menyumbang 67.3% manakala sektor komersial menyumbang 32.7% daripada jumlah sisa buangan makanan yang dihasilkan. Kekerapan sisa buangan makanan berkeadaan basah adalah lebih tinggi (p<0.05) di sektor komersial berbanding sektor isi rumah. Sisa nasi merupakan komponen sisa buangan makanan yang paling kerap dijana oleh sektor isi rumah dan sektor komersial. Penilaian ciri fizikokimia menunjukkan nilai pH, kandungan abu, bahan organik, karbon organik, nitrogen dan lemak serta nisbah C/N adalah berbeza (p<0.05) antara sisa buangan makanan yang dijana pada hari yang berlainan. Sisa buangan makanan bersifat asid (pH 4.82-5.17) mempunyai kandungan air (65.9-69.5%) dan lemak yang tinggi (13.1-20.2%) tetapi kandungan nitrogen yang rendah (0.63-0.85%). Walau bagaimanapun, nisbah C/N masih berada dalam julat (20-25) yang sesuai untuk pengkomposan yang berkesan. Oleh yang demikian, dengan memperkenalkan proses pengkomposan, sisa buangan makanan berkenaan berpotensi digunakan sebagai kompos.
    Matched MeSH terms: Nitrogen
  8. Anoxic transformations of wastewater organic matter in sewers--process kinetics, model concept and wastewater treatment potential
    Abdul-Talib S, Hvitved-Jacobsen T, Vollertsen J, Ujang Z
    Water Sci Technol, 2002;45(3):53-60.
    PMID: 11902481
    The sewer is an integral part of the urban wastewater system: the sewer, the wastewater treatment plant and the local receiving waters. The sewer is a reactor for microbial changes of the wastewater during transport, affecting the quality of the wastewater and thereby the successive treatment processes or receiving water impacts during combined sewer overflows. This paper presents the results of studies on anoxic processes, namely denitrification, in the bulk water phase of wastewater as it occurs in sewers. Experiments conducted on 12 different wastewater samples have shown that the denitrification process in the bulk wastewater can be simplified by the reduction of nitrate to nitrogen with significant accumulation of nitrite in the water phase. Utilization of nitrate was observed not to be limited by nitrate for concentrations above 5 gNO3-N/m3. The denitrification rates, under conditions of excess substrate and electron acceptor, were found to be in the range of 0.8-2.0 g NO3-N/(m3h). A discussion on the interaction of the sewer processes and the effects on a downstream located wastewater treatment plant (WWTP) is provided.
    Matched MeSH terms: Nitrogen/metabolism*
  9. Anti-inflammatory activities of cucurbitacin E isolated from Citrullus lanatus var. citroides: role of reactive nitrogen species and cyclooxygenase enzyme inhibition
    Abdelwahab SI, Hassan LE, Sirat HM, Yagi SM, Koko WS, Mohan S, et al.
    Fitoterapia, 2011 Dec;82(8):1190-7.
    PMID: 21871542 DOI: 10.1016/j.fitote.2011.08.002
    The in vivo and in vitro mechanistic anti-inflammatory actions of cucurbitacin E (CE) (Citrullus lanatus var. citroides) were examined. The results showed that LPS/INF-γ increased NO production in RAW264.7 macrophages, whereas L-NAME and CE curtailed it. CE did not reveal any cytotoxicity on RAW264.7 and WRL-68 cells. CE inhibited both COX enzymes with more selectivity toward COX-2. Intraperitoneal injection of CE significantly suppressed carrageenan-induced rat's paw edema. ORAC and FRAP assays showed that CE is not a potent ROS scavenger. It could be concluded that CE is potentially useful in treating inflammation through the inhibition of COX and RNS but not ROS.
    Matched MeSH terms: Reactive Nitrogen Species/metabolism*
  10. Fulltext Antidiabetic, Antihyperlipidemic, Antioxidant, Anti-inflammatory Activities of Ethanolic Seed Extract of Annona reticulata L. in Streptozotocin Induced Diabetic Rats
    Wen W, Lin Y, Ti Z
    Front Endocrinol (Lausanne), 2019;10:716.
    PMID: 31708869 DOI: 10.3389/fendo.2019.00716
    Annona reticulata L. (Bullock's heart) is a pantropic tree commonly known as custard apple, which is used therapeutically for a variety of maladies. The present research was carried out to evaluate the possible protective effects of Annona reticulata L. (A. reticulata) ethanolic seed extract on an experimentally induced type 2 diabetes rat model. Male Albino Wistar rats were randomly divided into five groups with six animals in each group viz., control rats in group I, diabetic rats in group II, diabetic rats with 50 and 100 mg/kg/bw of ethanolic seed extract of A. reticulata in groups III and IV, respectively, and diabetic rats with metformin in group V. Treatment was given for 42 consecutive days through oral route by oro-gastric gavage. Administration of A. reticulata seed extract to diabetes rats significantly restored the alterations in the levels of body weight, food and water intake, fasting blood glucose (FBG), insulin levels, insulin sensitivity, HbA1c, HOMA-IR, islet area and insulin positive cells. Furthermore, A. reticulata significantly decreased the levels of triglycerides, cholesterol, LDL, and significantly increased the HDL in diabetic rats. A. reticulata effectively ameliorated the enzymatic (ALT, AST, ALP, GGT) and modification of histopathological changes in diabetic rats. The serum levels of the BUN, creatinine levels, uric acid, urine volume, and urinary protein were significantly declined with a significant elevation in CCr in diabetic rats treated with A. reticulata. MDA and NO levels were significantly reduced with an enhancement in SOD, CAT, and GPx antioxidant enzyme activities in the kidney, liver, and pancreas of diabetic rats treated with A. reticulata. Diabetic rats treated with A. reticulata have shown up-regulation in mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1), Heme oxygenase-1 (HO-1) and protein expression level of Nrf2 with diminution in Keap1 mRNA expression level in pancreas, kidney, and liver. From the outcome of the current results, it can be inferred that seed extract of A. reticulata exhibits a protective effect in diabetic rats through its anti-diabetic, anti-hyperlipidemic, antioxidant and anti-inflammatory effects and could be considered as a promising treatment therapy in the treatment of diabetes mellitus.
    Matched MeSH terms: Blood Urea Nitrogen
  11. Application of nitrogen-rich porous organic polymer for the solid-phase synthesis of 2-amino-4H-benzo[b]pyran scaffolds using ball milling process
    Zaharani L, Khaligh NG, Mihankhah T, Johan MR
    Mol Divers, 2021 Feb;25(1):323-332.
    PMID: 32361887 DOI: 10.1007/s11030-020-10092-4
    This paper presents the efficient synthesis of 2-amino-4H-benzo[b]pyrans using mesoporous poly-melamine-formaldehyde as a polymeric heterogeneous catalyst. According to the principals of green chemistry, the reaction was performed by the planetary ball milling process at ambient and neat conditions. The heterogeneous catalyst could be reused up to five runs with no reducing of catalytic efficiency. A variety of substituted 2-amino-4H-benzo[b]pyrans were obtained in good to excellent yields under eco-friendly conditions. Other advantages of the current methodology include short reaction time, wide substrate-scope, and use of a metal-free polymeric catalyst. Also, the current method avoids the use of hazardous reagents and solvents, tedious workup and multi-step purification. This work revealed that porous organic polymers containing Lewis base sites having acceptor-donner hydrogen bonding functional groups, and high porosity could play a vital role in the promotion of the one-pot multicomponent reactions in the solid-phase synthesis.
    Matched MeSH terms: Nitrogen/chemistry*
  12. Application of response surface methodology (RSM) for optimisation of COD, NH3-N and 2,4-DCP removal from recycled paper wastewater in a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR)
    Muhamad MH, Sheikh Abdullah SR, Mohamad AB, Abdul Rahman R, Hasan Kadhum AA
    J Environ Manage, 2013 May 30;121:179-90.
    PMID: 23542216 DOI: 10.1016/j.jenvman.2013.02.016
    In this study, the potential of a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR) for removing chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N) and 2,4-dichlorophenol (2,4-DCP) from recycled paper wastewater was assessed. For this purpose, the response surface methodology (RSM) was employed, using a central composite face-centred design (CCFD), to optimise three of the most important operating variables, i.e., hydraulic retention time (HRT), aeration rate (AR) and influent feed concentration (IFC), in the pilot-scale GAC-SBBR process for recycled paper wastewater treatment. Quadratic models were developed for the response variables, i.e., COD, NH3-N and 2,4-DCP removal, based on the high value (>0.9) of the coefficient of determination (R(2)) obtained from the analysis of variance (ANOVA). The optimal conditions were established at 750 mg COD/L IFC, 3.2 m(3)/min AR and 1 day HRT, corresponding to predicted COD, NH3-N and 2,4-DCP removal percentages of 94.8, 100 and 80.9%, respectively.
    Matched MeSH terms: Nitrogen Compounds/isolation & purification*
  13. Applied chemometric approach in identification sources of air quality pattern in Selangor, Malaysia
    Ang KH
    Sains Malaysiana, 2018;47:471-479.
    In recent years, Malaysia has experienced quite a few number of chronic air pollution problems and it has become a
    major contributor to the deterioration of human health and ecosystems. This study aimed to assess the air quality data
    and identify the pattern of air pollution sources using chemometric analysis through hierarchical cluster analysis (HCA),
    discriminant analysis (DA), principal component analysis (PCA) and multiple linear regression analysis (MLR). The air
    quality data from January 2016 until December 2016 was obtained from the Department of Environment Malaysia. Air
    quality data from eight sampling stations in Selangor include the selected variables of nitrogen dioxide (NO2
    ), ozone (O3
    ),
    sulfur dioxide (SO2
    ), carbon monoxide (CO) and particulate matter (PM10). The HCA resulted in three clusters, namely low
    pollution source (LPS), moderate pollution source (MPS) and slightly high pollution source (SHPS). Meanwhile, DA resulted
    in two and four variables for the forward stepwise mode and the backward stepwise mode, respectively. Through PCA,
    it was identified that the main pollutants of LPS, MPS and SHPS came from industrial and vehicle emissions, agricultural
    systems, residential factors and natural emission sources. Among the three models yielded from the MLR analysis, it was
    found that SHPS is the most suitable model to be used for the prediction of Air Pollution Index. This study concluded that
    a clearer review and practical design of air quality monitoring network would be beneficial for better management of
    air pollution. The study also suggested that chemometric techniques have the ability to show significant information on
    spatial variability for large and complex air quality data.
    Matched MeSH terms: Nitrogen Dioxide
  14. Fulltext Aquaponics recirculation system: a sustainable food source for the future water conserves and resources
    Azizah Endut, Fathurrahman Lananan, Ahmad Jusoh, Wan Norsani Wan Nik, Nora'aini Ali
    Malaysian Journal of Applied Sciences, 2018;1(1):1-12.
    MyJurnal
    The current and escalating extent of soil degradation, water scarcity and environmental concern
    plaguing agricultural productivity, demands re-assessing the direction of food production. Aquaponics
    is a concept relatively new to modern food production methods and can contribute to food security.
    This study was conducted to establish sustainable aquaculture systems that maximize benefits and
    minimize the accumulation of detrimental compounds and other types of negative impacts on both
    natural and social environments. This study carried out at an average inflow rate of 1.28 m/day to
    evaluate the operation of the aquaponics recirculation system (ARS) on nutrients removal and growth
    and yield of African catfish as well as water spinach. A special design of ARS was used to provide
    nitrification of fishery wastewater, where the combination of sands and gravels in hydroponics trough,
    providing both surfaces for biofuel development and cultivation area for plants. Removal efficiencies
    of 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), total ammonia nitrogen
    (TAN), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), and orthophosphate (PO4
    3-
    ) were 82%, 89%,
    93%, 94%, 81%, and 80%, respectively. The feed conversion ratio (FCR) and specific growth rate
    (SGR) of African catfish were 1.08 and 3.34% day-1
    , respectively. The average water spinach
    production was 3.56 kg per m2
    . This study showed that ARS is a method of producing crop along with
    a healthy protein source and among the best alternatives for achieving economic and environmental
    sustainability.
    Matched MeSH terms: Nitrogen
  15. Aquatic insect biodiversity and water quality parameters of streams in northern Thailand
    Prommi T, Payakka A
    Sains Malaysiana, 2015;44:707-717.
    Biodiversity of aquatic insect and physicochemical water quality parameters in Mae Tao and Mae Ku watersheds were
    assessed bi-monthly from February 2011 to February 2012. A total of 59 families representing 9 orders were recorded.
    At order level, Trichoptera was found at the highest frequency in total abundance (45.75%) followed by Ephemeroptera
    (18.06%), Hemiptera (13.45%), Odonata (9.62%), Diptera (8.17%), Coleoptera (4.6%), Megaloptera (0.17%),
    Lepidoptera (0.11%) and Plecoptera (0.07%). The family Hydropsychidae was the most prominent and the most abundant
    aquatic insect taxa followed by Chironomidae. Water temperature, dissolved oxygen and ammonia-nitrogen were similar
    at all sampling stations. Significant variations in pH, electrical conductivity, total dissolved solids, sulfate, nitrate-nitrogen
    and alkalinity were found at all sampling stations. Taxa richness and diversity index significantly correlated with dissolved
    oxygen, sulfate, nitrate-nitrogen and ammonia-nitrogen (p<0.05, p<0.01). Physicochemical data and biological data
    showed that mostly the surface water quality in Mae Tao and Mae Ku watersheds were within Type III of The Surface
    Water Standard for Agriculture and Water Quality for Protection of Aquatic Resources in Thailand.
    Matched MeSH terms: Nitrogen
  16. Arboflorine, an unusual pentacyclic monoterpenoid indole alkaloid incorporating a third nitrogen atom
    Lim KH, Kam TS
    Org. Lett., 2006 Apr 13;8(8):1733-5.
    PMID: 16597153
    [structure: see text] A new indole alkaloid, arboflorine, possessing a novel pentacyclic carbon skeleton and incorporating a third nitrogen atom was obtained from the Malayan Kopsia arborea. The structure was established by spectroscopic analysis, and a possible biogenetic pathway from a preakuammicine-type precursor is presented.
    Matched MeSH terms: Nitrogen/chemistry*
  17. Arbuscular mycorrhizal fungal composition affects the growth and nutrient acquisition of two plants from a karst area
    Yuejun He, Changhong Jiang, Hao Yang, Yongjian Wang, Zhangcheng Zhong
    Sains Malaysiana, 2017;46:1701-1708.
    How the composition of the arbuscular mycorrhizal (AM) fungal community affects plant traits of different plant species in karst environments is poorly understood. Broussonetia papyrifera (a woody shrub) and Bidens pilosa (a herbaceous plant) growing in pots in limestone soil were inoculated with an AM fungus, either Funneliformis mosseae (FM), Diversispora versiformis (DV) or Glomus diaphanum (GD) or with an inoculum mixture of all three AM fungi (bn). B. papyrifera and B. pilosa seedlings inoculated with AM fungi showed a significant increase in biomass and nitrogen and phosphorus acquisition compared with the controls, which lacked mycorrhiza. Mixed fungal inoculations significantly enhanced biomass and nitrogen and phosphorus acquisition by B. papyrifera seedlings compared with single fungal inoculations. Nitrogen and phosphorus acquisition by B. papyrifera mycorrhizal seedlings was significantly greater than that of B. pilosa mycorrhizal seedlings. Fungal composition significantly influenced the mycorrhizal benefits of biomass and phosphorus acquisition and mixed fungal inoculations enhanced nitrogen acquisition. Plant species significantly affected nitrogen acquisition but did not have an effect on biomass and phosphorus benefits. We concluded that AM fungal associations increased plant growth and nutrient absorption and that in general a mixed inoculation of AM fungi enhanced biomass and nutrient acquisition more than a single AM fungal inoculation. In addition, a mycorrhizal association was more beneficial for B. papyrifera seedlings in terms of biomass and nutrient acquisition than for B. pilosa seedlings.
    Matched MeSH terms: Nitrogen
  18. Assessing water hyacinth (Eichhornia crassopes) and lettuce (Pistia stratiotes) effectiveness in aquaculture wastewater treatment
    Akinbile CO, Yusoff MS
    Int J Phytoremediation, 2012 Mar;14(3):201-11.
    PMID: 22567705
    Water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes) were analyzed to determine their effectiveness in aquaculture wastewater treatment in Malaysia. Wastewater from fish farm in Semanggol Perak, Malaysia was sampled and the parameters determined included, the pH, turbidity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), nitrite phosphate (PO4(3-)), nitrate (NO(3-)), nitrite (NO(-2)), ammonia (NH3), and total kjedahl nitrogen (TKN). Also, hydroponics system was set up and was added with fresh plants weights of 150 +/- 20 grams Eichhornia crassipes and 50 +/- 10 grams Pistia stratiotes during the 30 days experiment. The phytoremediation treatment with Eichhornia crassipes had pH ranging from 5.52 to 5.59 and from 4.45 to 5.5 while Pistia stratiotes had its pH value from 5.76 to 6.49 and from 6.24 to 7.07. Considerable percentage reduction was observed in all the parameters treated with the phytoremediators. Percentage reduction of turbidity for Eichhornia crassipes were 85.26% and 87.05% while Pistia stratiotes were 92.70% and 93.69% respectively. Similar reductions were observed in COD, TKN, NO(3-), NH3, and PO4(3-). The capability of these plants in removing nutrients was established from the study. Removal of aquatic macrophytes from water bodies is recommended for efficient water purification.
    Matched MeSH terms: Nitrogen/analysis
  19. Fulltext Assessment of Aqueous Extraction Methods on Extractable Organic Matter and Hydrophobic/Hydrophilic Fractions of Virgin Forest Soils
    Wan Mohd Zamri WMI, Sjahrir F, Yaacob NS, Dzulkafli NF, Ahmad MF, Abdullah H, et al.
    Molecules, 2021 Apr 23;26(9).
    PMID: 33922872 DOI: 10.3390/molecules26092480
    The assessment of water-extractable organic matter using an autoclave can provide useful information on physical, chemical, and biological changes within the soil. The present study used virgin forest soils from Chini Forest Reserve, Langkawi Island, and Kenyir Forest Reserve (Malaysia), extracted using different extraction methods. The dissolved organic carbon (DOC), total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), and ammonium-nitrate content were higher in the autoclave treatments, up to 3.0, 1.3, 1.2, and 1.4 times more than by natural extraction (extracted for 24 h at room temperature). Overall, the highest extractable DOC, TDN, TDP, ammonium and nitrate could be seen under autoclaved conditions 121 °C 2×, up to 146.74 mg C/L, 8.97 mg N/L, 0.23 mg P/L, 5.43 mg N mg/L and 3.47 N mg/L, respectively. The soil extracts became slightly acidic with a higher temperature and longer duration. Similar trends were observed in the humic and nonhumic substances, where different types of soil extract treatments influenced the concentrations of the fractions. Different soil extraction methods can provide further details, thus widening the application of soil extracts, especially in microbes.
    Matched MeSH terms: Nitrogen
  20. Fulltext Assessment of predictive models for chlorophyll-a concentration of a tropical lake
    Malek S, Syed Ahmad SM, Singh SK, Milow P, Salleh A
    BMC Bioinformatics, 2011;12 Suppl 13:S12.
    PMID: 22372859 DOI: 10.1186/1471-2105-12-S13-S12
    This study assesses four predictive ecological models; Fuzzy Logic (FL), Recurrent Artificial Neural Network (RANN), Hybrid Evolutionary Algorithm (HEA) and multiple linear regressions (MLR) to forecast chlorophyll- a concentration using limnological data from 2001 through 2004 of unstratified shallow, oligotrophic to mesotrophic tropical Putrajaya Lake (Malaysia). Performances of the models are assessed using Root Mean Square Error (RMSE), correlation coefficient (r), and Area under the Receiving Operating Characteristic (ROC) curve (AUC). Chlorophyll-a have been used to estimate algal biomass in aquatic ecosystem as it is common in most algae. Algal biomass indicates of the trophic status of a water body. Chlorophyll- a therefore, is an effective indicator for monitoring eutrophication which is a common problem of lakes and reservoirs all over the world. Assessments of these predictive models are necessary towards developing a reliable algorithm to estimate chlorophyll- a concentration for eutrophication management of tropical lakes.
    Matched MeSH terms: Nitrogen/analysis
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links