Intercalation of Organic Compounds in Lipid Bilayers

1994 ◽  
Vol 376 ◽  
Author(s):  
K.A. Hamacher ◽  
H. Kaiser ◽  
R. Kulasekere ◽  
D.L. Worcester
Keyword(s):  
Neutron Diffraction ◽  
Water Content ◽  
Lipid Bilayers ◽  
Organic Compounds ◽  
Chain Length ◽  
Narrow Band ◽  
Hydrocarbon Chain ◽  
Hydrophobic Compounds ◽  
Small Hydrophobic

ABSTRACTUsing neutron diffraction we studied the incorporation of small hydrophobic compounds into bilayers consisting of phosphatidylcholine (PC) and cholesterol. They were found to be localized in a narrow band at the center of the hydrocarbon region, between the two halves of the bilayer. The structures formed by introduction of the compounds are therefore intercalated structures with the long axis of the intercalated molecules lying in the plane of the bilayer. We worked with several bilayers which differed by the length of the hydrocarbon chain of the PC. The quality of the localization depended on the presence of cholesterol, the water content and the PC chain length.

Anesthetics significantly increase the amount of intramembrane water in lipid membranes

Soft Matter ◽  
2020 ◽  
Vol 16 (42) ◽  
pp. 9674-9682
Author(s):  
Sebastian Himbert ◽  
Lili Zhang ◽  
Richard J. Alsop ◽  
Viviana Cristiglio ◽  
Giovanna Fragneto ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Neutron Diffraction ◽  
Molecular Dynamics Simulations ◽  
Water Content ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Water Distribution ◽  
Dynamics Simulations

We studied the effect anesthetics on the water distribution in lipid bilayers by combining all-atom molecular dynamics simulations and neutron diffraction experiments. We found that anesthetics increase the intramembrane water content by up to 25%.

scholarly journals Structure and Interdigitation of Chain-Asymmetric Phosphatidylcholines and Milk Sphingomyelin in the Fluid Phase

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1441
Author(s):  
Moritz P. K. Frewein ◽  
Milka Doktorova ◽  
Frederick A. Heberle ◽  
Haden L. Scott ◽  
Enrico F. Semeraro ◽  
...  
Keyword(s):  
Chain Length ◽  
Hydration Shell ◽  
Fluid Phase ◽  
Hydrocarbon Chain ◽  
Specific Model ◽  
Glycerol Backbone ◽  
Membrane Composition ◽  
Membrane Structures ◽  
Hydrocarbon Chain Length ◽  
Dynamics Simulations

We addressed the frequent occurrence of mixed-chain lipids in biological membranes and their impact on membrane structure by studying several chain-asymmetric phosphatidylcholines and the highly asymmetric milk sphingomyelin. Specifically, we report trans-membrane structures of the corresponding fluid lamellar phases using small-angle X-ray and neutron scattering, which were jointly analyzed in terms of a membrane composition-specific model, including a headgroup hydration shell. Focusing on terminal methyl groups at the bilayer center, we found a linear relation between hydrocarbon chain length mismatch and the methyl-overlap for phosphatidylcholines, and a non-negligible impact of the glycerol backbone-tilting, letting the sn1-chain penetrate deeper into the opposing leaflet by half a CH2 group. That is, penetration-depth differences due to the ester-linked hydrocarbons at the glycerol backbone, previously reported for gel phase structures, also extend to the more relevant physiological fluid phase, but are significantly reduced. Moreover, milk sphingomyelin was found to follow the same linear relationship suggesting a similar tilt of the sphingosine backbone. Complementarily performed molecular dynamics simulations revealed that there is always a part of the lipid tails bending back, even if there is a high interdigitation with the opposing chains. The extent of this back-bending was similar to that in chain symmetric bilayers. For both cases of adaptation to chain length mismatch, chain-asymmetry has a large impact on hydrocarbon chain ordering, inducing disorder in the longer of the two hydrocarbons.

scholarly journals Volatile Organic Compounds (VOCs) Emitted from Coated Furniture Units

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 806
Author(s):  
Ozge Cemiloglu Ulker ◽  
Onur Ulker ◽  
Salim Hiziroglu
Keyword(s):  
Air Quality ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Indoor Air ◽  
Exposure Period ◽  
Point Of View ◽  
Health Concerns ◽  
Volatile Organic ◽  
Significant Health

Volatile organic compounds (VOCs) are the main source influencing the overall air quality of an environment. It is a well-known fact that coated furniture units, in the form of paints and varnishes, emit VOCs, reducing the air quality and resulting in significant health problems. Exposure time to such compounds is also an important parameter regarding their possible health effects. Such issues also have a greater influence when the exposure period is extended. The main objective of this study was to review some of the important factors for the emission of VOCs from coated furniture, from the perspective of material characteristics, as well as health concerns. Some methods for controlling VOC emissions to improve indoor air quality, from the point of view recent regulations and suggestions, are also presented in this work.

scholarly journals Effects of different drying rates on the physiological quality of Coffea canephora Pierre seeds

2005 ◽  
Vol 17 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Sttela Dellyzete Veiga Franco da Rosa ◽  
Delacyr da Silva Brandão Júnior ◽  
Édila Vilela de Resende Von Pinho ◽  
André Delly Veiga ◽  
Luiz Hildebrando de Castro e Silva
Keyword(s):  
Water Content ◽  
Storage Temperature ◽  
Removal Rate ◽  
Coffea Canephora ◽  
Development Stage ◽  
Seed Vigor ◽  
Drying Rate ◽  
Physiological Quality ◽  
Drying Rates

Desiccation tolerance in seeds depends on the species, development stage and drying conditions, especially the water removal rate. Coffea seeds are considered of intermediate performance, because they tolerate relative dehydration compared to orthodox seeds and are sensitive to low temperatures. The objective of this study was to verify the effect of different drying rates on the viability and storability of Coffea canephora seeds. A complete randomized experimental design was used, in a factorial 3 x 5 x 2 design, with three drying rates (fast, intermediate and slow), five final mean water contents after drying (51, 42, 33, 22 and 15 %) and two storage temperatures (10 and 20°C). The germination and seed vigor assessments, using radicle protrusion, cotyledon leaf opening, seedling emergence and emergence speed index, were performed shortly after drying and after two and four months storage. It was observed that with reduction in the water content there was reduction in the germination values and seed vigor, for all the drying rates. The greatest reductions in physiological quality occurred when the seeds were dried quickly and the best results were obtained at the intermediate drying rate. There was an effect of drying rate and storage temperature on the physiological quality of the seeds, and lower germination and vigor values were observed in seeds with lower water content stored at 20°C. C. canephora seeds were tolerant to desiccation down to 15 % water content and can be stored for four months at 10°C. A temperature of 20ºC can be used to store C. canephora seeds, as long as the water content is not reduced to values below 22 % water content.

scholarly journals Penurunan mutu dan pendugaan umur simpan sup krim instan labu kuning diperkaya tempe untuk lansia dengan metode accelerated shelf life testing (ASLT)

2020 ◽  
Vol 8 (2) ◽  
pp. 134-142
Author(s):  
Salma Shafrina Aulia ◽  
Budi Setiawan ◽  
Tiurma Sinaga ◽  
Ahmad Sulaeman
Keyword(s):  
Lipid Oxidation ◽  
Shelf Life ◽  
Water Content ◽  
Water Activity ◽  
Critical Parameter ◽  
Storage Period ◽  
Life Testing ◽  
Quality Of Water ◽  
Long Time

Background: Instant pumpkin cream soup enriched with tempeh had fulfilled 10% Recommended Dietary Allowances (RDA) for elderly so that it can be used as an easy-to-serve snack, but decreasing quality of instant cream soup will be happened if the instant cream soup was stored for a long time. Objectives: This study aimed to analyze quality of water content, water activity and lipid oxidation in instant pumpkin cream soup during storage and estimated the shelf life of pumpkin cream soup enriched with tempeh.Method:  Quality storage was analyzed using of water content, water activity (aw) and lipid oxidation. Estimation of shelf life was analyzed using Arrhenius Accelerated Shelf Life Testing (ASLT) model.Results: The results showed that the water content, aw levels and lipid oxidation of instant pumpkin cream soup increased during the storage period. The critical parameter used in this study was lipid oxidation. Instant cream soup without the addition of tempeh can last 447 days  while the cream soup with the addition of tempeh has a shelf life of 433 days.Conclusion: Quality of instant pumpkin cream soup decreased during the storage period and it would be expired over a year.

scholarly journals Effect of Hydrocarbon Chain Length of Amphiphilic Ruthenium Dyes on Solid-State Dye-Sensitized Photovoltaics

Nano Letters ◽  
2005 ◽  
Vol 5 (7) ◽  
pp. 1315-1320 ◽  
Author(s):  
Lukas Schmidt-Mende ◽  
Jessica E. Kroeze ◽  
James R. Durrant ◽  
Md. K. Nazeeruddin ◽  
Michael Grätzel
Keyword(s):  
Solid State ◽  
Chain Length ◽  
Hydrocarbon Chain ◽  
Dye Sensitized ◽  
Hydrocarbon Chain Length ◽  
Ruthenium Dyes

Alkanethiol Adsorption on Platinum: Chain Length Effects on the Quality of Self-Assembled Monolayers

2011 ◽  
Vol 115 (36) ◽  
pp. 17788-17798 ◽  
Author(s):  
María Alejandra Floridia Addato ◽  
Aldo A. Rubert ◽  
Guillermo A. Benítez ◽  
Mariano H. Fonticelli ◽  
Javier Carrasco ◽  
...  
Keyword(s):  
Chain Length ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Platinum Chain ◽  
Length Effects

PERCEPATAN PENGOMPOSAN TANDAN KOSONG KELAPA SAWIT (TKKS) DENGAN PEMBERIAN UREA (Acceleration Composting Empty Fruit Bunches (Efb) With The Application Of Urea)

AgriPeat ◽  
2019 ◽  
Vol 18 (02) ◽  
pp. 113-124
Author(s):  
Journal Journal
Keyword(s):  
Weight Loss ◽  
Water Content ◽  
Palm Oil ◽  
Organic N ◽  
Empty Fruit Bunches ◽  
Randomized Design ◽  
Compost Application ◽  
Completely Randomized Design ◽  
Total P

                                                                                                                                   ABSTRAK Kelapa sawit merupakan tanaman perkebunan yang memegang peranan penting dalam industri pangan. Luas perkebunan kelapa sawit di Indonesia pada tahun 2014 mencapai 10 juta Ha. Pertumbuhan yang pesat diikuti dengan produksi crude palm oil (CPO) dan palm karnel oil (PKO) yang juga meningkat, sekaligus produk sampingan berupa limbah. Salah satu limbah pabrik kelapa sawit yang jumlahnya besar adalah tandan kosong kelapa sawit (TKKS). Tandan kosong kelapa sawit merupakan limbah organik yang berpotensi dimanfaatkan dibidang pertanian. Akan tetapi, TKKS memiliki nilai C/N yang cukup tinggi, akibatnya sukar dan lama untuk terdekomposisi. Salah satu cara pemanfaatan TKKS adalah dengan dilakukan pengomposan dengan pengkayaan urea. Diharapkan dengan perlakuan tersebut TKKS akan cepat terdekomposisi dan dapat segera dimanfaatkan oleh tanaman. Penelitian ini bertujuan untuk (1) mengetahui pengaruh pemberian urea terhadap pengomposan TKKS dan (2) mengetahui pengaruh peningkatan dosis urea terhadap kualitas kompos TKKS. Rancangan yang digunakan dalam penelitian ini adalah Rancangan Acak Lengkap (RAL) faktor tunggal dengan 5 perlakuan, yaitu U1 (urea 0 g setara dengan nilai C/N=), U2 (urea 30,9 g setara dengan nilai C/N=), U3 (urea 79,3 g setara dengan nilai C/N=), U4 (urea 176,1 g setara dengan nilai C/N=) dan U5 (urea 466,3 g setara dengan C/N = ) dan 9 ulangan, sehingga diperoleh 45 satuan percobaan. Hasil penelitian menunjukan bahwa pemberian urea berpengaruh sangat nyata terhadap susut bobot, kadar air, nilai pH kompos, C-organik, N-total, P-tersedia, dan nilai C/N, selain itu pemberian urea mengakibatkan terjadi perubahan tekstur dan warna pada kompos TKKS. Pemberian dosis urea 466,3 g mampu meningkatkan kandungan N-total, serta menurunkan nilai C/N dan nilai pH kompos. Pemberian dosis urea 79,3 g atau setara dengan C/N = mampu meningkatkan kandungan P-tersedia dan kadar air, menurunkan susut bobot dan kandungan C-organik, serta menunjukan perubahan tekstur dan warna yang lebih baik. Kata kunci: tanda kosongkelapa sawit (TKSS), kompos, urea                                                                                                                                        ABSTRACT Empty fruit bunches (EFB) is a solid wastes produced in large quantity from palm oil industry. Empty fruit bunches can be used as compost material, additionally difficult to decompose because it contain cellulose, hemicellulose, and lignin, as well as value of ratio C/N is high. Use EFB as compost material through the provision of urea has been done in this research. Urea are expected to reduce the value of ratio C/N and became a starter for microbial decomposers. The purpose of this research were (1) to determine the effect of urea on composting of EFB and (2) to determine the effect of increasing doses of urea to the quality of compost of EFB. This research was used a single factor of Completely Randomized Design (CRD) with 5 treatments, namely U1 (urea 0 g), U2 (urea 30,9 g), U3 (urea 79,3 g), U4 (urea 176,1 g), and U5 (urea 466,3 g), and 9 replications, until result 45 experimental units. The result showed that urea significant effect on weight loss, water content, value of pH compost, C-organic, N-total, P-available, and value of ratio C/N, besides urea resulted Widodoe, K. dkk Percepatan Pengomposan Tandan Kosong Kelapa Sawit…..…. 114 in a change in texture and color on the compost EFB. Application of urea 466,3 g was able to increase the content of N-total, reduce the value of ratio C/N and the value of pH compost. Application of urea 79,3 g can improve the content of P-available and water content, reduce the weight loss and the content of C-organic, and showed the changes in texture and color as better. Keywords: empty fruit bunches, compost, urea

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