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Topic Review
Lipids of Sulfolobus spp.
Archaea, and thereby, Sulfolobus spp. exhibit a unique lipid composition of ether lipids, which are altered in regard to the ratio of diether to tetraether lipids, number of cyclopentane rings and type of head groups, as a coping mechanism against environmental changes. Sulfolobales mainly consist of C40-40 tetraether lipids (caldarchaeol) and partly of C20-20 diether lipids (archaeol). A variant of caldarchaeol called glycerol dialkylnonitol tetraether (GDNT) has only been found in Sulfolobus and other members of the Creanarchaeota phylum so far. Altering the numbers of incorporated cyclopentane rings or the the diether to tetraether ratio results in more tightly packed membranes or vice versa.
  • 2.1K
  • 26 Oct 2020
Topic Review
Quantum Biology
Recent evidence suggests that a broad range of complex and dynamic processes in living systems could exploit quantum effects to enhance and/or regulate biological functions. These non-trivial quantum effects may play a crucial role in maintaining the non-equilibrium state of biomolecular systems so as to achieve biological advantages that cannot be understood within the boundaries of classical physics. Quantum biology is the study of such quantum aspects of living systems. 
  • 2.1K
  • 24 Mar 2021
Topic Review
Collagen D-Band Periodicity
The molecules follow a quarter-staggered fashion packing, which leads to the formation of the so call D-band periodicity. This D-band periodicity is a repeating banding pattern of about 67 nm (depending on the different tissue) and includes gap and overlap regions. Collagen fibrils form bundles and fibers by appropriate alignment.
  • 2.0K
  • 06 Apr 2022
Topic Review
Peptide Inhibitors of Kv1.5
The human voltage gated potassium channel Kv1.5 that conducts the IKur current is a key determinant of the atrial action potential. This channel is an attractive target for the management of Atrial Fibrillation (AF). A wide range of peptide toxins from venomous animals are targeting ion channels, including mammalian channels. These peptides usually have a much larger interacting surface with the ion channel compared to small molecule inhibitors and thus, generally confer higher selectivity to the peptide blockers. To date, literature has known two peptides that inhibit IKur: Ts6 and Osu1. T
  • 2.0K
  • 30 Dec 2021
Topic Review
The BIANCA Biophysical Model
Cancer ion therapy is constantly growing, thanks to its increased precision and, for heavy ions, its increased biological effectiveness (RBE) with respect to conventional photon therapy. The complex dependence of RBE on many factors demands for biophysical modelling. Up to now only the Local Effect Model (LEM), the Microdosimetric Kinetic Model (MKM) and the “mixed-beam” model are used in clinics. In this work the BIANCA biophysical model, after extensive benchmarking in vitro, was applied to develop a database predicting cell survival for different ions, energies and doses. Following interface with the FLUKA Monte Carlo transport code, for the first time BIANCA was benchmarked against in vivo data obtained by C-ion or proton irradiation of the rat spinal cord. The latter is a well-established model for CNS (Central Nervous System) late effects, which in turn are the main dose-limiting factor for head-and-neck tumors. Furthermore, these data have been considered to validate the LEM version applied in clinics. Although further benchmarking is desirable, the agreement between simulations and data suggests that BIANCA can predict RBE for C-ion or proton treatment of head-and-neck tumors. In particular, the agreement with proton data may be relevant if the current assumption of a constant proton RBE of 1.1 is revised. This work provides the bases for future benchmarking against patient data, as well as the development of other databases for specific tumor types and/or normal tissues.
  • 1.9K
  • 02 Nov 2020
Topic Review
Thermal Load and Heat Transfer in Dental Implants
Heat is a kinetic process whereby energy flows from between two systems, hot-to-cold objects. In oro-dental implantology, conductive heat transfer/(or thermal stress) is a complex physical phenomenon to analyze and consider in treatment planning. Hence, ample research has attempted to measure heat-production to avoid over-heating during bone-cutting and drilling for titanium (Ti) implant-site preparation and insertion, thereby preventing/minimizing early (as well as delayed) implant-related complications and failure. The goal is two-fold: (A) the standard heat equation is proposed to be solved, modifying the imposed boundary conditions without any additional source term, and on the other hand, (B) a gap is filled in the literature via obtaining an exact analytical solution of a somewhat simplified problem, which nevertheless, encapsulates the physics and reproduces the results already found in previous works via numerical analyses. In addition, for the first time, the intrinsic time is introduced and involved herein, a “proper” time that characterizes the geometry of the dental implant fixture and overall system, and how the interplay between that time and the exposure time influences temperature changes, and subsequent implant survival, are shown. Thus, this work aims to complement the overall clinical diagnostic and treatment plan for enhanced biological one–implant interface and mechanical implant stability and success rates, whether for immediate or delayed implant loading strategies.
  • 1.9K
  • 11 Mar 2022
Topic Review
Structure of Blood–Brain Barrier and Substance Transportation
The complex structure of the blood–brain barrier (BBB), which blocks nearly all large biomolecules, hinders drug delivery to the brain and drug assessment, thus decelerating drug development. Conventional in vitro models of BBB cannot mimic some crucial features of BBB in vivo including a shear stress environment and the interaction between different types of cells. There is a great demand for a new in vitro platform of BBB that can be used for drug delivery studies.
  • 1.8K
  • 01 Mar 2023
Topic Review
Signal Peptide Interactions during ER Translocation
Cleavable endoplasmic reticulum (ER) signal peptides (SPs) and other non-cleavable signal sequences target roughly a quarter of the human proteome to the ER. These short peptides, mostly located at the N-termini of proteins, are highly diverse. For most proteins targeted to the ER, it is the interactions between the signal sequences and the various ER targeting and translocation machineries such as the signal recognition particle (SRP), the protein-conducting channel Sec61, and the signal peptidase complex (SPC) that determine the proteins’ target location and provide translocation fidelity. 
  • 1.8K
  • 16 Dec 2021
Topic Review
Hibernation
Torpor and hibernation are natural physiological processes. Torpor refers to a pe-riod of metabolic suppression with a duration from a few hours to several weeks. The state of torpor is probably older in evolutionary terms and was likely a survival strate-gy of protomammals. Hibernation is a more elaborate behavior, structured in many long bouts of torpor separated by brief interbouts of arousal.
  • 1.8K
  • 23 Feb 2021
Topic Review
Intrinsically Disordered Proteins in Diseases
Many proteins and protein segments cannot attain a single stable three-dimensional structure under physiological conditions; instead, they adopt multiple interconverting conformational states. Such intrinsically disordered proteins or protein segments are highly abundant across proteomes, and are involved in various effector functions.
  • 1.7K
  • 02 Dec 2022
Topic Review
Eye Movement Events
Eye tracking is the process of tracking the movement of the eyes to know exactly where and for how long a person is looking. Classifying raw eye-tracker data into eye movement events reduces the complexity of eye movement analysis.
  • 1.7K
  • 25 Nov 2022
Topic Review
Negative Reversibly Switchable Fluorescent Proteins
The advancement of super-resolution imaging (SRI) relies on fluorescent proteins with novel photochromic properties. Using light, the reversibly switchable fluorescent proteins (RSFPs) can be converted between bright and dark states for many photocycles and their emergence has inspired the invention of advanced SRI techniques. The general photoswitching mechanism involves the chromophore cis-trans isomerization and proton transfer for negative and positive RSFPs and hydration–dehydration for decoupled RSFPs. However, a detailed understanding of these processes on ultrafast timescales (femtosecond to millisecond) is lacking, which fundamentally hinders the further development of RSFPs. For a negative RSFP such as Dronpa, the light used to induce fluorescence can often switch the protein from the on to off state; whereas for a positive RSFP like Padron, the same light can turn more proteins on. In contrast, the decoupled RSFPs can use separate light with different wavelengths for fluorescence excitation and photoswitching.
  • 1.7K
  • 23 Jun 2022
Topic Review
Electrical Source Imaging
Electrical Source Imaging (ESI) is an imaging technique utilized to localize the activated brain regions by incorporating temporal and spatial components from electroencephalogram (EEG) signals. 
  • 1.7K
  • 13 Jul 2021
Topic Review
Molecular Simulations of RNA-Dependent RNA Polymerase of SARS-CoV-2
Molecular dynamics (MD) simulations are powerful theoretical methods that can reveal biomolecular properties, such as structure, fluctuations, and ligand binding, at the atomic level. All-atom MD simulations elucidated a difference in the dynamic properties of RNA-dependent RNA polymerases (RdRps) in severe acute respiratory syndrom coronavirus 2 (SARS-CoV-2) and SARS-CoV, which may cause activity differences of these RdRps. RdRp is also a drug target for Coronavirus disease 2019. Nucleotide analogs, such as remdesivir and favipiravir, are considered to be taken up by RdRp and inhibit RNA replication. The recognition mechanism of RdRp for these drug molecules and adenosine triphosphate (ATP) was revealed by MD simulations at the atomic detail. In addition, various simulation studies on the complexes of SARS-CoV-2 RdRp with several nucleotide analogs are also presented.
  • 1.7K
  • 20 Feb 2023
Topic Review
Solubility and Aggregation of Proteins
Protein solubility is based on the compatibility of the specific protein surface with the polar aquatic environment. The exposure of polar residues to the protein surface promotes the protein’s solubility in the polar environment. The application of 3D GAuss function allows identification of accordant/discordant regions in proteis. The discordant ones usually represent the localisation of biological activity. 
  • 1.6K
  • 11 Oct 2021
Topic Review
TPC1 in plants
TPC1 in plants is localized in the vacuolar membrane. Its activity is strictly regulated by several factors emphasizing its complex structure and function. The physiological role of TPC1 is under debate. The TPC1 hyperactive version fou2 (carring D454N mutation) is characterized by an overproduction of jasmonate acid (JA), however the tpc1-2 knockout mutant has no pronounced phenotype. The intriguing concept of Ca2+-induced Ca2+ release was assigned to Vicia faba TPC1 in 1994 by Ward and Schroeder, however it has still not been confirmed for the model plant Arabidopsis thaliana.
  • 1.6K
  • 27 Oct 2020
Topic Review
Cell Cycle and Its Regulation
A decisive characteristic of life is the reproductive capacity of cells, which it does through a collection of highly complex and ordered regulatory process commonly known as the cell cycle. The cell cycle combines DNA replication with chromosomal segregation in an oscillatory manner. In this way, the cell cycle coordinates the precise replication of the genome through specific events to ensure that the duplicated genetic material is distributed equally to each daughter cell. The repetition of this process leads to the exponential proliferation of cells. This process is classically described as interphase and mitosis (M) phase. Most of the cell cycle is in interphase, which encompasses Gap 1 (G1), synthesis (S), and Gap 2 (G2) phases. During the interphase, the cell grows, replicates genetic materials, and repairs DNA damage and replication errors. M phase, a relatively short period, consists of prophase, metaphase, anaphase, and telophase, which completes the equal distribution of genome and cytoplasmic components. Following interphase, most nondividing cells exit the cell cycle at G1 into G0 phase (quiescence). G0 was originally used to describe cells that are not in the cell cycle but with the potential for division. The rate of cell cycling varies with the developmental stage and cell type. In general, the cell cycle is most active during development, as cells in early embryos can proliferate and differentiate to form tissues and organs. The cell cycle involves numerous life processes, and it is closely related to the growth and proliferation of eukaryotic cells, development of organisms, regulation of DNA damage repair, and occurrence of diseases.
  • 1.6K
  • 25 Jun 2021
Topic Review
Photosensitive Substances
Photodynamic therapy (PDT) is part of photochemotherapy and requires the presence of a photosensitive substance (drug, PS), oxygen, and a powerful light source in the area of absorption of the PS used.
  • 1.6K
  • 13 Apr 2021
Topic Review Peer Reviewed
The Applications of Microphysiological Systems in Biomedicine: Impact on Urologic and Orthopaedic Research
Microphysiological systems (MPSs) are in vitro models that can incorporate dynamic stimuli such as flow, pressure and contraction in cell culture, enabling the formation of cellular architectures and retrieving physiological function often absent in conventional 2D-cell culture. MPS applications saw a substantial growth in recent years, drawing attention from industry as a strategy to optimize pre-clinical drug-development purposes, as well as from biomedical research, to fill a gap between in vivo and in vitro models. Several MPS platforms are now available and are employed in the development of bone and kidney complex systems for urologic and orthopaedic research. These advances have enabled, for example, the in vitro modelling of bone regeneration and renal drug secretion, and have dramatic potential to improve research into both orthopaedic and urology cancers. 
  • 1.6K
  • 16 Jun 2022
Topic Review
Electrical Resistance Measurement
The blood–brain barrier (BBB) represents the tightest endothelial barrier within the cardiovascular system characterized by very low ionic permeability.
  • 1.6K
  • 25 Jun 2021
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