scholarly journals Intrinsic curvature in normal and inverted lipid structures and in membranes

1996 ◽  
Vol 70 (5) ◽  
pp. 2248-2255 ◽  
Author(s):  
D. Marsh
Keyword(s):  
Intrinsic Curvature ◽  
Lipid Structures

Gold liposomes

1996 ◽  
Vol 54 ◽  
pp. 898-899
Author(s):  
James F. Hainfeld
Keyword(s):  
Direct Methods ◽  
Important Class ◽  
Double Bonds ◽  
Membrane Phospholipids ◽  
Essential Ingredient ◽  
Lipid Structures

Lipids are an important class of molecules, being found in membranes, HDL, LDL, and other natural structures, serving essential roles in structure and with varied functions such as compartmentalization and transport. Synthetic liposomes are also widely used as delivery and release vehicles for drugs, cosmetics, and other chemicals; soap is made from lipids. Lipids may form bilayer or multilammellar vesicles, micelles, sheets, tubes, and other structures. Lipid molecules may be linked to proteins, carbohydrates, or other moieties. EM study of this essential ingredient of life has lagged, due to lack of direct methods to visualize lipids without extensive alteration. OsO4 reacts with double bonds in membrane phospholipids, forming crossbridges. This has been the method of choice to both fix and stain membranes, thus far. An earlier work described the use of tungstate clusters (W11) attached to lipid moieties to form lipid structures and lipid probes.

scholarly journals Stochastic vs. deterministic magnetic coding in designed cylindrical nanowires for 3D magnetic networks

Nanoscale ◽  
2021 ◽  
Author(s):  
Cristina Bran ◽  
Elias Saugar ◽  
José Ángel Fernández-Roldán ◽  
Rafael Perez del Real ◽  
Agustina Asenjo ◽  
...  
Keyword(s):  
Information Technologies ◽  
Intrinsic Curvature ◽  
Planar Systems ◽  
3D Information

Advances in cylindrical nanowires for 3D information technologies profit from intrinsic curvature that introduces significant differences with regards to planar systems. A model is proposed to control the stochastic and...

Effects of potassium deficiency and simulated acid rain, alone and in combination, on the ultrastructure of Scots pine needles

1989 ◽  
Vol 19 (11) ◽  
pp. 1402-1411 ◽  
Author(s):  
Toini Holopainen ◽  
Pekka Nygren
Keyword(s):  
Acid Rain ◽  
Scots Pine ◽  
Potassium Deficiency ◽  
Simulated Acid Rain ◽  
Sand Culture ◽  
Short Term ◽  
Transmission Electron ◽  
Resting Period ◽  
Lipid Structures ◽  
Parenchyma Tissue

The effects of potassium deficiency and artificial acid precipitation, alone and in combination, on Scots pine (Pinussilvestris L.) needles were studied using transmission electron microscopy. The seedling material was grown in quartz sand culture and watered with nutrient solution containing 45, 20, 10, or 5 mg of potassium/L; the concentration of other nutrients was constant and equally available for all seedlings. A portion of the seedlings from each group received consecutive acidified water spraying of pH 4.5, 4.0, 3.5, and 3.0, each for 4 days with a 3-day resting period between applications. The potassium deficiency caused an increase in the proportional vacuolar space and severe vesiculation of the tonoplast. Irregularly shaped lipid structures increased in number in the cytoplasm, and lipid bodies also appeared in the vacuoles and occasionally in the chloroplasts. The symptoms related to potassium deficiency were more severe in the transfusion parenchyma cells than in the mesophyll. The lowest level of potassium produced almost complete disorganization of the cellular structures in the transfusion parenchyma tissue, but severe changes were also seen in the mesophyll. The simulated acid rain treatment caused the formation of protrusions in the chloroplasts and an increase in irregularly shaped lipid structures in the cytoplasm throughout the mesophyll tissue, but no clear symptoms were observed inside the bundle sheath. In general, the changes caused by acid rain in the chloroplasts were slight and did not cause serious disorganization of these organelles. When the seedlings were exposed to combination treatment, the typical symptoms of both exposures were observable. The results suggest that the stresses caused by potassium deficiency and short-term foliar acid rain treatment can be distinguished in the needle ultrastructure.

Recent advances on immunosuppressive drugs and remyelination enhancers for the treatment of multiple sclerosis

2021 ◽  
Vol 27 ◽  
Author(s):  
Jennifer Cadenas-Fernández ◽  
Pablo Ahumada-Pascual ◽  
Luis Sanz Andreu ◽  
Ana Velasco
Keyword(s):  
Multiple Sclerosis ◽  
Intracellular Signaling ◽  
Demyelinating Disease ◽  
Lipid Synthesis ◽  
Immunosuppressive Drugs ◽  
Nerve Fibers ◽  
Myelin Sheaths ◽  
Demyelinating Lesions ◽  
The Central Nervous System ◽  
Lipid Structures

: Mammalian nervous systems depend crucially on myelin sheaths covering the axons. In the central nervous system, myelin sheaths consist of lipid structures which are generated from the membrane of oligodendrocytes (OL). These sheaths allow fast nerve transmission, protect axons and provide them metabolic support. In response to specific traumas or pathologies, these lipid structures can be destabilized and generate demyelinating lesions. Multiple sclerosis (MS) is an example of a demyelinating disease in which the myelin sheaths surrounding the nerve fibers of the brain and spinal cord are damaged. MS is the leading cause of neurological disability in young adults in many countries, and its incidence has been increasing in recent decades. Related to its etiology, it is known that MS is an autoimmune and inflammatory CNS disease. However, there are no effective treatments for this disease and the immunomodulatory therapies that currently exist have proven limited success since they only delay the progress of the disease. Nowadays, one of the main goals in the MS research is to find treatments which allows the recovery of neurological disabilities due to demyelination. To this end, different approaches, such as modulating intracellular signaling or regulating the lipid metabolism of OLs, are being considered. Here, in addition to immunosuppressive or immunomodulatory drugs that reduce the immune response against myelin sheaths, we review a diverse group of drugs that promotes endogenous remyelination in MS patients and whose use may be interesting as potential therapeutic agents in MS disease. To this end, we compile specific treatments against MS that are currently in the market with remyelination strategies which have entered into human clinical trials for future reparative MS therapies. The method used in this study is a systematic literature review on PubMed, Web of Science and Science Direct databases up to May 31, 2020. To narrow down the search results in databases, more specific keywords, such as, “myelin sheath”, “remyelination”, “demyelination”, “oligodendrocyte” and “lipid synthesis” were used to focus the search. We favoured papers published after January, 2015, but did not exclude earlier seminal papers.

scholarly journals Advanced Microfluidic Technologies for Lipid Nano-Microsystems from Synthesis to Biological Application

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 141
Author(s):  
Bruna Carvalho ◽  
Bruno Ceccato ◽  
Mariano Michelon ◽  
Sang Han ◽  
Lucimara de la Torre
Keyword(s):  
Lipid Nanoparticles ◽  
Future Trends ◽  
Biological Applications ◽  
Biological Application ◽  
Shell Nanoparticles ◽  
Cellular Environment ◽  
Wide Range ◽  
Core Shell Nanoparticles ◽  
New Strategies ◽  
Lipid Structures

Microfluidics is an emerging technology that can be employed as a powerful tool for designing lipid nano-microsized structures for biological applications. Those lipid structures can be used as carrying vehicles for a wide range of drugs and genetic materials. Microfluidic technology also allows the design of sustainable processes with less financial demand, while it can be scaled up using parallelization to increase production. From this perspective, this article reviews the recent advances in the synthesis of lipid-based nanostructures through microfluidics (liposomes, lipoplexes, lipid nanoparticles, core-shell nanoparticles, and biomimetic nanovesicles). Besides that, this review describes the recent microfluidic approaches to produce lipid micro-sized structures as giant unilamellar vesicles. New strategies are also described for the controlled release of the lipid payloads using microgels and droplet-based microfluidics. To address the importance of microfluidics for lipid-nanoparticle screening, an overview of how microfluidic systems can be used to mimic the cellular environment is also presented. Future trends and perspectives in designing novel nano and micro scales are also discussed herein.

scholarly journals Manifold curvature and Ehrenfest forces with a moving basis

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Jessica Halliday ◽  
Emilio Artacho
Keyword(s):  
Extrinsic Curvature ◽  
Quantum States ◽  
Basis Set ◽  
Electronic Subsystem ◽  
Intrinsic Curvature ◽  
Geometrical Meaning

Known force terms arising in the Ehrenfest dynamics of quantum electrons and classical nuclei, due to a moving basis set for the former, can be understood in terms of the curvature of the manifold hosting the quantum states of the electronic subsystem. Namely, the velocity-dependent terms appearing in the Ehrenfest forces on the nuclei acquire a geometrical meaning in terms of the intrinsic curvature of the manifold, while Pulay terms relate to its extrinsic curvature.

Effect of intrinsic curvature and edge tension on the stability of binary mixed-membrane three-junctions

2016 ◽  
Vol 145 (7) ◽  
pp. 074901 ◽  
Author(s):  
Jasmine M. Gardner ◽  
Markus Deserno ◽  
Cameron F. Abrams
Keyword(s):  
Intrinsic Curvature ◽  
The Stability ◽  
Edge Tension

scholarly journals σs-dependent promoters inEscherichia coliare located in DNA regions with intrinsic curvature

1993 ◽  
Vol 21 (16) ◽  
pp. 3667-3670 ◽  
Author(s):  
Manuel Espinosa- Urgel ◽  
Antonio Tormo
Keyword(s):  
Intrinsic Curvature
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