Displaying publications 1 - 20 of 188 in total

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  1. Temperature dependence of the Raman spectrum of 1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one
    de Toledo TA, da Costa RC, Al-Maqtari HM, Jamalis J, Pizani PS
    Spectrochim Acta A Mol Biomol Spectrosc, 2017 Jun 05;180:9-17.
    PMID: 28259100 DOI: 10.1016/j.saa.2017.02.051
    The heterocyclic chalcone containing thiophene ring 1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one, C13H9ClOS was synthesized and investigated using experimental techniques such as nuclear magnetic resonance (1H and 13C NMR), Fourier transform infrared spectroscopy (FTIR) at room temperature, differential scanning calorimeter (DSC) from room temperature to 500K and Raman scattering at the temperature range 10-413K in order to study its structure and vibrational properties as well as stability and possible phase transition. Density functional theory (DFT) calculations were performed to determine the vibrational spectrum viewing to improve the knowledge of the material properties. A reasonable agreement was observed between theoretical and experimental Raman spectrum taken at 10K since anharmonic effects of the molecular motion is reduced at low temperatures, leading to a more comprehensive assignment of the vibrational modes. Increasing the temperature up to 393K, was observed the typical phonon anharmonicity behavior associated to changes in the Raman line intensities, line-widths and red-shift, in special in the external mode region, whereas the internal modes region remains almost unchanged due its strong chemical bonds. Furthermore, C13H9ClOS goes to melting phase transition in the temperature range 393-403K and then sublimates in the temperature range 403-413K. This is denounced by the disappearance of the external modes and the absence of internal modes in the Raman spectra, in accordance with DSC curve. The enthalpy (ΔH) obtained from the integration of the endothermic peak in DSC curve centered at 397K is founded to be 121.5J/g.
    Matched MeSH terms: Cold Temperature
  2. Natural Variation in Freezing Tolerance and Cold Acclimation Response in Arabidopsis thaliana and Related Species
    Zuther E, Lee YP, Erban A, Kopka J, Hincha DK
    Adv Exp Med Biol, 2018 10 6;1081:81-98.
    PMID: 30288705 DOI: 10.1007/978-981-13-1244-1_5
    During low-temperature exposure, temperate plant species increase their freezing tolerance in a process termed cold acclimation. The molecular mechanisms involved in cold acclimation have been mostly investigated in Arabidopsis thaliana. In addition, other Brassicaceae species related to A. thaliana have been employed in recent years to study plant stress responses on a phylogenetically broader basis and in some cases with extremophile species with a much higher stress tolerance. In this paper, we briefly summarize cold acclimation responses in A. thaliana and current knowledge about cold acclimation in A. thaliana relatives with special emphasis on Eutrema salsugineum and two closely related Thellungiella species. We then present a transcriptomic and metabolomic analysis of cold acclimation in five A. thaliana and two E. salsugineum accessions that differ widely in their freezing tolerance. Differences in the cold responses of the two species are discussed.
    Matched MeSH terms: Cold Temperature
  3. Fulltext Late-spring frost risk between 1959 and 2017 decreased in North America but increased in Europe and Asia
    Zohner CM, Mo L, Renner SS, Svenning JC, Vitasse Y, Benito BM, et al.
    Proc Natl Acad Sci U S A, 2020 06 02;117(22):12192-12200.
    PMID: 32393624 DOI: 10.1073/pnas.1920816117
    Late-spring frosts (LSFs) affect the performance of plants and animals across the world's temperate and boreal zones, but despite their ecological and economic impact on agriculture and forestry, the geographic distribution and evolutionary impact of these frost events are poorly understood. Here, we analyze LSFs between 1959 and 2017 and the resistance strategies of Northern Hemisphere woody species to infer trees' adaptations for minimizing frost damage to their leaves and to forecast forest vulnerability under the ongoing changes in frost frequencies. Trait values on leaf-out and leaf-freezing resistance come from up to 1,500 temperate and boreal woody species cultivated in common gardens. We find that areas in which LSFs are common, such as eastern North America, harbor tree species with cautious (late-leafing) leaf-out strategies. Areas in which LSFs used to be unlikely, such as broad-leaved forests and shrublands in Europe and Asia, instead harbor opportunistic tree species (quickly reacting to warming air temperatures). LSFs in the latter regions are currently increasing, and given species' innate resistance strategies, we estimate that ∼35% of the European and ∼26% of the Asian temperate forest area, but only ∼10% of the North American, will experience increasing late-frost damage in the future. Our findings reveal region-specific changes in the spring-frost risk that can inform decision-making in land management, forestry, agriculture, and insurance policy.
    Matched MeSH terms: Cold Temperature*
  4. Fulltext Antarctica: bioprospecting, access and benefit-sharing of genetic resources
    Zakri, A.H.
    ASM Science Journal, 2009;3(2):200-202.
    MyJurnal
    Recent studies by the United Nations University - Institute of Advanced Studies (UNU-IAS) demonstrate that bioprospecting is taking place in Antarctica and the Southern Ocean and that related commercial applications were being marketed. The bioprospectors’ interest in Antarctica stems from two reasons. First, the lack of knowledge surrounding Antarctic biota provides opportunities to discover novel organisms of potential use to biotechnology. Second, Antarctica’s environmental extremes, such as cold temperatures, extreme aridity and salinity present conditions in which biota have evolved unique characteristics for survival (UNU-IAS 2003). Thus bioprospecting opportunities include, inter alia, the discovery of novel bioactives in species found in cold and dry lithic habitat, novel pigments found in hyper-saline lakes and antifreezes in sea-lakes (Cheng & Cheng 1999).
    Matched MeSH terms: Cold Temperature
  5. Relationship Between ABCB1 Polymorphisms and Cold Pain Sensitivity Among Healthy Opioid-naive Malay Males
    Zahari Z, Lee CS, Ibrahim MA, Musa N, Mohd Yasin MA, Lee YY, et al.
    Pain Pract, 2017 09;17(7):930-940.
    PMID: 27996183 DOI: 10.1111/papr.12546
    BACKGROUND: Endogenous and exogenous opioids are substrates of the permeability glycoprotein (P-gp) efflux transporter, which is encoded by the ABCB1 (MDR1) gene. Genetic polymorphisms of ABCB1 may contribute to interindividual differences in pain modulation and analgesic responses. We investigated the relationship between ABCB1 polymorphisms and cold pain sensitivity among healthy males.

    METHODS: Cold pain responses, including pain threshold and pain tolerance, were measured using the cold-pressor test (CPT). DNA was extracted from whole blood and genotyped for ABCB1 polymorphisms, including c.1236C>T (rs1128503), c.2677G>T/A (rs2032582), and c.3435C>T (rs1045642), using the allelic discrimination real-time polymerase chain reaction.

    RESULTS: A total of 152 participants were recruited in this observational study. Frequencies of mutated allele for c.1236C>T, c.2677G>T/A, and c.3435C>T polymorphisms were 56.6%, 49.7%, and 43.4%, respectively. Our results revealed an association of the CGC/CGC diplotype (c.1236C>T, c.2677G>T/A, and c.3435C>T) with cold pain sensitivity. Participants with the CGC/CGC diplotype had 90% and 72% higher cold pain thresholds (87.62 seconds vs. 46.19 seconds, P = 0.010) and cold pain tolerances (97.24 seconds vs. 56.54 seconds, P = 0.021), respectively, when compared with those without the diplotype.

    CONCLUSION: The CGC/CGC diplotype of ABCB1 polymorphisms was associated with variability in cold pain threshold and pain tolerance in healthy males.

    Matched MeSH terms: Cold Temperature/adverse effects*
  6. ABCB1 Polymorphisms and Cold Pressor Pain Responses: Opioid-Dependent Patients on Methadone Maintenance Therapy
    Zahari Z, Lee CS, Ibrahim MA, Musa N, Mohd Yasin MA, Lee YY, et al.
    Nurs Res, 2017 Mar-Apr;66(2):134-144.
    PMID: 28252574 DOI: 10.1097/NNR.0000000000000204
    BACKGROUND: Methadone is a substrate of the P-glycoprotein efflux transporter, which is encoded by ABCB1 (MDR1), and thus, ABCB1 polymorphisms may influence the transport of methadone at the blood-brain barrier, affecting its adverse effects.

    OBJECTIVES: This study investigated the association between ABCB1 polymorphisms and cold pressor pain responses among opioid-dependent patients on methadone maintenance therapy (MMT).

    METHODS: Malay male opioid-dependent patients receiving MMT (n = 148) were recruited. Cold pressor pain responses (pain threshold, pain tolerance, and pain intensity) were measured at 0, 2, 4, 8, 12, and 24 hours post-methadone dose. DNA was extracted from whole blood and genotyped for ABCB1 polymorphisms including 1236C>T (rs1128503), 2677G>T/A (rs2032582), and 3435C>T (rs1045642) using the allelic discrimination real-time polymerase chain reaction. Repeated-measure analysis of variance between-group analysis was used to compare the three cold pressor pain responses and ABCB1 polymorphisms (1236C>T, 2677G>T/A, and 3435C>T) according to genotypes and allelic additive models, genotype dominant and recessive models, haplotypes, and diplotypes.

    RESULTS: Patients with 2677 GG or 2677G allele had the lowest pain threshold compared with 2677G>T/A genotypes or alleles (p = .007 and .002, respectively). Haplotype analysis showed a significant association between ABCB1 haplotypes and pain threshold (p = .02). Patients with 2677G allele had the lowest pain tolerance compared to those with 2677T and 2677A alleles (2677G < 2677T < 2677A allele carriers; p = .05). In terms of pain intensity scores, patients with 2677 GG or 2677G allele had the highest scores compared to other 2677G>T/A genotypes or alleles (p = .04 and .008, respectively). Haplotype analysis revealed a significant difference between patients with CGC haplotype and those without this haplotype (p = .02).

    DISCUSSION: To the best of our knowledge, this study provides the first evidence that ABCB1 polymorphisms are associated with cold pressor pain responses among Malay male patients with opioid dependence on MMT. The results may provide an initial prediction on heightened pain sensitivity or hyperalgesia for individuals who are carriers of the ABCB1 polymorphisms.
    Matched MeSH terms: Cold Temperature*
  7. Effect of ultrasonic pre-treatment on low temperature acid hydrolysis of oil palm empty fruit bunch
    Yunus R, Salleh SF, Abdullah N, Biak DR
    Bioresour Technol, 2010 Dec;101(24):9792-6.
    PMID: 20719502 DOI: 10.1016/j.biortech.2010.07.074
    Various pre-treatment techniques change the physical and chemical structure of the lignocellulosic biomass and improve hydrolysis rates. The effect of ultrasonic pre-treatment on oil palm empty fruit bunch (OPEFB) fibre prior to acid hydrolysis has been evaluated. The main objective of this study was to determine if ultrasonic pre-treatment could function as a pre-treatment method for the acid hydrolysis of OPEFB fibre at a low temperature and pressure. Hydrolysis at a low temperature was studied using 2% sulphuric acid; 1:25 solid liquid ratio and 100 degrees C operating temperature. A maximum xylose yield of 58% was achieved when the OPEFB fibre was ultrasonicated at 90% amplitude for 45min. In the absence of ultrasonic pre-treatment only 22% of xylose was obtained. However, no substantial increase of xylose formation was observed for acid hydrolysis at higher temperatures of 120 and 140 degrees C on ultrasonicated OPEFB fibre. The samples were then analysed using a scanning electron microscope (SEM) to describe the morphological changes of the OPEFB fibre. The SEM observations show interesting morphological changes within the OPEFB fibre for different acid hydrolysis conditions.
    Matched MeSH terms: Cold Temperature*
  8. Characterization of natural low transition temperature mixtures (LTTMs): Green solvents for biomass delignification
    Yiin CL, Quitain AT, Yusup S, Sasaki M, Uemura Y, Kida T
    Bioresour Technol, 2016 Jan;199:258-264.
    PMID: 26253419 DOI: 10.1016/j.biortech.2015.07.103
    The aim of this work was to characterize the natural low transition temperature mixtures (LTTMs) as promising green solvents for biomass pretreatment with the critical characteristics of cheap, biodegradable and renewable, which overcome the limitations of ionic liquids (ILs). The LTTMs were derived from inexpensive commercially available hydrogen bond acceptor (HBA) and l-malic acid as the hydrogen bond donor (HBD) in distinct molar ratios of starting materials and water. The peaks involved in the H-bonding shifted and became broader for the OH groups. The thermal properties of the LTTMs were not affected by water while the biopolymers solubility capacity of LTTMs was improved with the increased molar ratio of water and treatment temperature. The pretreatment of oil palm biomass was consistence with the screening on solubility of biopolymers. This work provides a cost-effective alternative to utilize microwave hydrothermal extracted green solvents such as malic acid from natural fruits and plants.
    Matched MeSH terms: Cold Temperature*
  9. EgRBP42 encoding an hnRNP-like RNA-binding protein from Elaeis guineensis Jacq. is responsive to abiotic stresses
    Yeap WC, Ooi TE, Namasivayam P, Kulaveerasingam H, Ho CL
    Plant Cell Rep, 2012 Oct;31(10):1829-43.
    PMID: 22699852 DOI: 10.1007/s00299-012-1297-x
    RNA-binding proteins (RBPs) have been implicated as regulatory proteins involved in the post-transcriptional processes of gene expression in plants under various stress conditions. In this study, we report the cloning and characterization of a gene, designated as EgRBP42, encoding a member of the plant heterogeneous nuclear ribonucleoprotein (hnRNP)-like RBP family from oil palm (Elaeis guineensis Jacq.). EgRBP42 consists of two N-terminal RNA recognition motifs and a glycine-rich domain at the C-terminus. The upstream region of EgRBP42 has multiple light-responsive, stress-responsive regulatory elements and regulatory elements associated with flower development. Real-time RT-PCR analysis of EgRBP42 showed that EgRBP42 was expressed in oil palm tissues tested, including leaf, shoot apical meristem, root, female inflorescence, male inflorescence and mesocarp with the lowest transcript level in the roots. EgRBP42 protein interacted with transcripts associated with transcription, translation and stress responses using pull-down assay and electrophoretic mobility shift assay. The accumulation of EgRBP42 and its interacting transcripts were induced by abiotic stresses, including salinity, drought, submergence, cold and heat stresses in leaf discs. Collectively, the data suggested that EgRBP42 is a RBP, which responds to various abiotic stresses and could be advantageous for oil palm under stress conditions. Key message EgRBP42 may be involved in the post-transcriptional regulation of stress-related genes important for plant stress response and adaptation.
    Matched MeSH terms: Cold Temperature
  10. Correlations between allocation to foliar phosphorus fractions and maintenance of photosynthetic integrity in six mangrove populations as affected by chilling
    Yan L, Sunoj VSJ, Short AW, Lambers H, Elsheery NI, Kajita T, et al.
    New Phytol, 2021 12;232(6):2267-2282.
    PMID: 34610157 DOI: 10.1111/nph.17770
    Chilling restrains the distribution of mangroves. We tested whether foliar phosphorus (P) fractions and gene expression are associated with cold tolerance in mangrove species. We exposed seedlings of six mangrove populations from different latitudes to favorable, chilling and recovery treatments, and measured their foliar P concentrations and fractions, photochemistry, nighttime respiration, and gene expression. A Kandelia obovata (KO; 26.45°N) population completely and a Bruguiera gymnorhiza (Guangxi) (BGG; 21.50°N) population partially (30%) survived chilling. Avicennia marina (24.29°N), and other B. gymnorhiza (26.66°N, 24.40°N, and 19.62°N) populations died after chilling. Photosystems of KO and photosystem I of BGG were least injured. During chilling, leaf P fractions, except nucleic acid P in three populations, declined and photoinhibition and nighttime respiration increased in all populations, with the greatest impact in B. gymnorhiza. Leaf nucleic acid P was positively correlated with photochemical efficiency during recovery and nighttime respiration across populations for each treatment. Relatively high concentrations of nucleic acid P and metabolite P were associated with stronger chilling tolerance in KO. Bruguiera gymnorhiza exhibited relatively low concentrations of organic P in favorable and chilling conditions, but its partially survived population showed stronger compensation in nucleic acid P and Pi concentrations and gene expression during recovery.
    Matched MeSH terms: Cold Temperature
  11. Toluene promotes lid 2 interfacial activation of cold active solvent tolerant lipase from Pseudomonas fluorescens strain AMS8
    Yaacob N, Mohamad Ali MS, Salleh AB, Rahman RNZRA, Leow ATC
    J Mol Graph Model, 2016 07;68:224-235.
    PMID: 27474867 DOI: 10.1016/j.jmgm.2016.07.003
    The utilization of cold active lipases in organic solvents proves an excellent approach for chiral synthesis and modification of fats and oil due to the inherent flexibility of lipases under low water conditions. In order to verify whether this lipase can function as a valuable synthetic catalyst, the mechanism concerning activation of the lid and interacting solvent residues in the presence of organic solvent must be well understood. A new alkaline cold-adapted lipase, AMS8, from Pseudomonas fluorescens was studied for its structural adaptation and flexibility prior to its exposure to non-polar, polar aprotic and protic solvents. Solvents such as ethanol, toluene, DMSO and 2-propanol showed to have good interactions with active sites. Asparagine (Asn) and tyrosine (Tyr) were key residues attracted to solvents because they could form hydrogen bonds. Unlike in other solvents, Phe-18, Tyr-236 and Tyr-318 were predicted to have aromatic-aromatic side-chain interactions with toluene. Non-polar solvent also was found to possess highest energy binding compared to polar solvents. Due to this circumstance, the interaction of toluene and AMS8 lipase was primarily based on hydrophobicity and molecular recognition. The molecular dynamic simulation showed that lid 2 (residues 148-167) was very flexible in toluene and Ca(2+). As a result, lid 2 moves away from the catalytic areas, leaving an opening for better substrate accessibility which promotes protein activation. Only a single lid (lid 2) showed the movement following interactions with toluene, although AMS8 lipase displayed double lids. The secondary conformation of AMS8 lipase that was affected by toluene observed a reduction of helical strands and increased coil structure. Overall, this work shows that cold active lipase, AMS8 exhibits distinguish interfacial activation and stability in the presence of polar and non-polar solvents.
    Matched MeSH terms: Cold Temperature*
  12. Fulltext The Role of Solvent-Accessible Leu-208 of Cold-Active Pseudomonas fluorescens Strain AMS8 Lipase in Interfacial Activation, Substrate Accessibility and Low-Molecular Weight Esterification in the Presence of Toluene
    Yaacob N, Ahmad Kamarudin NH, Leow ATC, Salleh AB, Raja Abd Rahman RNZ, Mohamad Ali MS
    Molecules, 2017 Aug 12;22(8).
    PMID: 28805665 DOI: 10.3390/molecules22081312
    The alkaline cold-active lipase from Pseudomonas fluorescens AMS8 undergoes major structural changes when reacted with hydrophobic organic solvents. In toluene, the AMS8 lipase catalytic region is exposed by the moving hydrophobic lid 2 (Glu-148 to Gly-167). Solvent-accessible surface area analysis revealed that Leu-208, which is located next to the nucleophilic Ser-207 has a focal function in influencing substrate accessibility and flexibility of the catalytic pocket. Based on molecular dynamic simulations, it was found that Leu-208 strongly facilitates the lid 2 opening via its side-chain. The KM and Kcat/KM of L208A mutant were substrate dependent as it preferred a smaller-chain ester (pNP-caprylate) as compared to medium (pNP-laurate) or long-chain (pNP-palmitate) esters. In esterification of ethyl hexanoate, L208A promotes a higher ester conversion rate at 20 °C but not at 30 °C, as a 27% decline was observed. Interestingly, the wild-type (WT) lipase's conversion rate was found to increase with a higher temperature. WT lipase AMS8 esterification was higher in toluene as compared to L208A. Hence, the results showed that Leu-208 of AMS8 lipase plays an important role in steering a broad range of substrates into its active site region by regulating the flexibility of this region. Leu-208 is therefore predicted to be crucial for its role in interfacial activation and catalysis in toluene.
    Matched MeSH terms: Cold Temperature
  13. Fulltext Transfer free graphene growth on SiO2 substrate at 250 °C
    Vishwakarma R, Rosmi MS, Takahashi K, Wakamatsu Y, Yaakob Y, Araby MI, et al.
    Sci Rep, 2017 03 02;7:43756.
    PMID: 28251997 DOI: 10.1038/srep43756
    Low-temperature growth, as well as the transfer free growth on substrates, is the major concern of graphene research for its practical applications. Here we propose a simple method to achieve the transfer free graphene growth on SiO2 covered Si (SiO2/Si) substrate at 250 °C based on a solid-liquid-solid reaction. The key to this approach is the catalyst metal, which is not popular for graphene growth by chemical vapor deposition. A catalyst metal film of 500 nm thick was deposited onto an amorphous C (50 nm thick) coated SiO2/Si substrate. The sample was then annealed at 250 °C under vacuum condition. Raman spectra measured after the removal of the catalyst by chemical etching showed intense G and 2D peaks together with a small D and intense SiO2 related peaks, confirming the transfer free growth of multilayer graphene on SiO2/Si. The domain size of the graphene confirmed by optical microscope and atomic force microscope was about 5 μm in an average. Thus, this approach will open up a new route for transfer free graphene growth at low temperatures.
    Matched MeSH terms: Cold Temperature
  14. Fulltext Insight into Improved Thermostability of Cold-Adapted Staphylococcal Lipase by Glycine to Cysteine Mutation
    Veno J, Rahman RNZRA, Masomian M, Ali MSM, Kamarudin NHA
    Molecules, 2019 Aug 30;24(17).
    PMID: 31480403 DOI: 10.3390/molecules24173169
    Thermostability remains one of the most desirable traits in many lipases. Numerous studies have revealed promising strategies to improve thermostability and random mutagenesis often leads to unexpected yet interesting findings in engineering stability. Previously, the thermostability of C-terminal truncated cold-adapted lipase from Staphylococcus epidermidis AT2 (rT-M386) was markedly enhanced by directed evolution. The newly evolved mutant, G210C, demonstrated an optimal temperature shift from 25 to 45 °C and stability up to 50 °C. Interestingly, a cysteine residue was randomly introduced on the loop connecting the two lids and accounted for the only cysteine found in the lipase. We further investigated the structural and mechanistic insights that could possibly cause the significant temperature shift. Both rT-M386 and G210C were modeled and simulated at 25 °C and 50 °C. The results clearly portrayed the effect of cysteine substitution primarily on the lid stability. Comparative molecular dynamics simulation analysis revealed that G210C exhibited greater stability than the wild-type at high temperature simulation. The compactness of the G210C lipase structure increased at 50 °C and resulted in enhanced rigidity hence stability. This observation is supported by the improved and stronger non-covalent interactions formed in the protein structure. Our findings suggest that the introduction of a single cysteine residue at the lid region of cold-adapted lipase may result in unexpected increased in thermostability, thus this approach could serve as one of the thermostabilization strategies in engineering lipase stability.
    Matched MeSH terms: Cold Temperature*
  15. Comparative toxicity of nine metals to two Malaysian aquatic dipterian larvae with reference to temperature variation
    Vedamanikam VJ, Shazilli NA
    Bull Environ Contam Toxicol, 2008 Jun;80(6):516-20.
    PMID: 18414763 DOI: 10.1007/s00128-008-9413-x
    A study was conducted to determine the suitability of using selected aquatic dipterian larvae for biomonitoring bioassays. The organisms included a member of the biting midge family that was identified as Culicoides furens and a member of the non-biting midge family, identified as Chironomus plumosus. Median lethal toxicity tests were conducted to observe the variation between metal sensitivities between the two larval forms and how variations in temperature could affect the experimental setup. Nine heavy metals were used in the study. It was observed that the 96 h LC(50) (in mg/L) for the different metals was found to be Zn-16.21 (18.55 +/- 13.87); Cr-0.96 (1.08 +/- 0.84); Ag-4.22 (6.87 +/- 1.57); Ni-0.42 (0.59 +/- 0.25); Hg-0.42 (0.59 +/- 0.25); Pb-16.21 (18.31 +/- 14.11); Cu-42.24 (45.18 +/- 39.30); Mn-4.22 (7.19 +/- 1.25); Cd-0.42 (0.59 +/- 0.25) for the Chironomus plumosus and Zn-4.22 (6.56 +/- 1.88); Cr-0.42 (0.54 +/- 0.30); Ag-0.42 (0.54 +/- 0.30); Ni-0.42 (0.54 +/- 0.30); Hg-0.04 (0.07 +/- 0.01); Pb-0.42 (0.54 +/- 0.30); Cu-42.24 (45.18 +/- 39.30); Mn-4.22 (6.56 +/- 1.88); Cd-0.42 (0.54 +/- 0.30) in the case of the Culicoides furens. With temperature as a variable the LC(50) values were observed to increase from 2.51 mg/L at 10 degrees C to 4.22 ppm at 30 degrees C and to reduce slightly to 3.72 mg/L at 35 degrees C as seen in the case of Zn. It was also observed that at 40 degrees C thermal toxicity and chemical toxicity overlapped as 100% mortality was observed in the controls. This trend was observed in all metals for both C. plumosus and C. furens. Thus indicating temperature played an important role in determining LC(50) values of toxicants.
    Matched MeSH terms: Cold Temperature/adverse effects*
  16. The 143 and 300 K polymorphs of hexamethylenetetraminium 2,4-dinitrophenolate monohydrate
    Usman A, Chantrapromma S, Fun HK
    Acta Crystallogr C, 2001 Dec;57(Pt 12):1443-6.
    PMID: 11740112
    The title compound, 3,5,7-triaza-1-azoniatricyclo[3.3.1.1(3,7)]decane 2,4-dinitrophenolate monohydrate, C6H13N4+*C6H3N2O5-*H2O, the 1:1 hydrate adduct of hexamethylenetetramine (HMT) and 2,4-dinitrophenol, undergoes a temperature phase transition. In the room-temperature phase, the adduct crystallizes in the monoclinic P2(1)/m space group, whereas in the low-temperature phase, the adduct crystallizes in the triclinic P1 space group. This phase transition is reversible, with the transition temperature at 273 K, and the phase transition is governed by hydrogen bonds and weak interactions. In both these temperature-dependent polymorphs, the crystal structure is alternately layered with sheets of hexamethylenetetramine and sheets of dinitrophenol stacked along the c axis. The hexamethylenetetramine and dinitrophenol moieties are linked by intermolecular hydrogen bonds. The water molecule in the adduct plays an important role, forming O-H...O hydrogen bonds which, together with C-H...O hydrogen bonds, bridge the adducts into molecular ribbons. Extra hydrogen bonds and weak interactions exist for the low-temperature polymorph and these interconnect the molecular ribbons into a three-dimensional packing structure. Also in these two temperature-dependent polymorphs, dinitrophenol acts as a hydrogen-bond acceptor and HMT acts as a hydrogen-bond donor.
    Matched MeSH terms: Cold Temperature
  17. Cloning of glyceraldehyde-3-phosphate dehydrogenase from an Antarctic psychrophilic bacterium by inverse and splinkerette PCR
    Too WC, Liew YC, Few LL
    J Basic Microbiol, 2008 Oct;48(5):430-5.
    PMID: 18759222 DOI: 10.1002/jobm.200800008
    Psychrophiles are organisms that thrive in cold environments. One of the strategies for their cold adaptation is the ability to synthesize cold-adapted enzymes. These enzymes usually display higher catalytic efficiency and thermolability at lower temperatures compared to their mesophilic and thermophilic counterparts. In this work, a psychrophilic bacterium codenamed pi9 was selected for the cloning of the gene encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an enzyme in the glycolytic pathway. Here, the cloning of an 1,113 bp fragment of GAPDH gene which covers the 1,002 bp open reading frame by using multiple PCR steps is described. The partial sequence of this gene was PCR amplified by using degenerate primers followed by the cloning of the flanking sequences by inverse and splinkerette PCR techniques. The success in cloning the GAPDH gene by PCR has bypassed the more time consuming genomic library construction and screening method. The full length GAPDH protein was subsequently expressed in E. coli, purified as His-tag protein and confirmed to be catalytically active. This work demonstrated the use of multiple PCR techniques to clone a gene based solely on sequence comparison. It also laid the foundation for further biochemical and structural characterizations of GAPDH from a psychrophilic bacterium by providing a highly purified recombinant protein sample.
    Matched MeSH terms: Cold Temperature
  18. Effects of Environmental Factors on Growth and Artemisinin Content of Artemisia annua L
    Thu BT, Van Minh T, Lim BP, Keng CL
    Trop Life Sci Res, 2011 Dec;22(2):37-43.
    PMID: 24575216
    Seeds of two selected clones of Artemisia annua L., TC1 and TC2, were germinated in a greenhouse. Four-week-old seedlings from both clones were grown in the Thù Đúc province of Ho Chi Minh City on 2(nd) January 2009 and Đà Lat on 20(th) January 2009. During this study period in Thù Đúc province, which is situated 4-5 m above sea level, was experiencing a tropical, dry season with temperatures ranging from 26.2°C-32.8°C. Đà Lat, situated at 1500-2000 m above sea level, was having temperate, dry season with lower temperatures, ranging from 10.5°C-18.0°C. The high temperatures and low elevation in Thù Đúc Province led to slow vegetative growth for all of the plants from the two different clones and the artemisinin contents were significantly reduced. The temperate environment of Đà Lat supported robustly growing plants, with plant heights and branch lengths 4-5 times taller and longer that those planted at Thù Đúc Province. The artemisinin contents of A. annua planted at Đà Lat were 3-4 times greater than those cultivated at Thù Đúc Province. Hence, this study indicated that the variations observed in plant growth and artemisinin contents were due to temperature effects because the two selected clones were genetically homogenous. The cold weather of Đà Lat was suitable for planting of A. annua as opposed to the tropical weather of Thù Đúc Province.
    Matched MeSH terms: Cold Temperature
  19. Investigation of indoor thermal comfort and energy demand in different locations along the sub-Himalayan belt - A simulation based study
    Thapa S, Zaki SA
    J Therm Biol, 2024 Feb;120:103809.
    PMID: 38364574 DOI: 10.1016/j.jtherbio.2024.103809
    The sub-Himalayan region extends over 2500 km, extending over several countries. Though the effects of climate change is widely anticipated in the diverse but fragile ecosystem of the Himalayas, very less research has been conducted on the indoor environment of the buildings in these regions. In this study, a pre-validated model of 3-storey concrete residential building was used to study the indoor performance and thermal comfort in the face of climate change in the 8 (eight) different hill towns (hill stations) located from west to the east. Rise in ambient and indoor conditions were evident as a part of climate change with colder locations being affected the most. The thermal comfort assessment using both the climate chamber based PMV model and adaptive models revealed the decrease in cold related discomfort and increase in hot related discomfort. On an overall, the indoor conditions improved in these cold locations. The indoor and outdoor thermal condition and thermal comfort plummeted significantly with latitude and elevation. The heating demand in the future climate reduced by about 50-70 % in warmer locations, while the cooling demand increased by as much as 1000-2000 % in cold locations, respectively. Additionally, it was seen that the thermal environment and comfort both declined more rapidly with elevation in the locations lying in the western Himalayas as compared to those in the eastern Himalayas.
    Matched MeSH terms: Cold Temperature
  20. Fulltext Assessment of temperature effects on early larval development survival of hatchery-reared tropical oyster, Crassostrea iredalei
    Teh, Chiew Peng, Tan, Aileen Shau Hwai, Vengatesen, Thiyagarajan
    Trop Life Sci Res, 2016;27(11):111-116.
    MyJurnal
    The influence of the cool and warm temperatures on early life development and
    survival of tropical oyster, Crassostrea iredalei was studied. D-hinged larvae (day 1 larvae)
    were reared to three different temperatures (20°C, 27°C, and 34°C) for nine days. Oyster
    larvae reared in temperature 27°C, acted as control (ambient temperature). The highest
    survival rate occurred when the larvae were reared in 20°C and 27°C. Larvae reared at
    34°C exhibited reduced survival but increase in the growth rate. The growth rate in larvae
    reared in high temperature (34°C) was significantly higher compared to larvae reared in
    20°C and 27°C (p
    Matched MeSH terms: Cold Temperature
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