scholarly journals Learning the Science Behind Bacteriocins Through Lacticin 3147; a Promising Lantibiotic

2019 ◽  
Vol 2 (2) ◽  
pp. 79-80
Author(s):  
Allison Wan ◽  
Cherry Ibarra-Romero ◽  
John Vederas ◽  
Sorina Chiorean
Keyword(s):  
Lactococcus Lactis ◽  
High Performance ◽  
Synergistic Effects ◽  
Food Preservation ◽  
Great Promise ◽  
Antimicrobial Effects ◽  
Molecular Weights ◽  
Lacticin 3147 ◽  
Cell Pellet ◽  
Cell Components

As microorganisms continue to develop resistance and survive against many different forms of antimicrobial solutions, such as antibiotics, the threat that antimicrobial resistance poses grows considerably. One solution to this persistent issue could be bacteriocins: ribosomally synthesized antimicrobial peptides that are synthesized by bacteria. In this study, the specific lantibiotic—a subclass of bacteriocin—used was lacticin 3147, which is comprised of two components: A1 and A2. Lacticin 3147 was first purified and isolated in order to properly analyze its antimicrobial effects, which show potential use in antibiotics or food preservation. The procedure started with growing the producer bacteria strain, Lactococcus lactis DPC 3147 in a broth which was later used to inoculate a large volume of media. This media was then separated through centrifugation into two components: the supernatant and cell pellet, both of which were each individually concentrated and purified through a series of columns. Approximately one milliliter of each component was run through a High Performance Liquid Chromatography (HPLC) machine, and the resulting chromatograms interpreted to evaluate and compare the concentrations of lacticin 3147 produced in the liquid media portion (supernatant) and the cell components (cell pellet). Subsequently, fractions were collected from all runs from the HPLC and further subjected to Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI TOF) mass spectrometry. This allows to test the molecular weights of the compounds in the samples to check if they aligned with the known molecular weights of both the A1 and A2 components of lacticin 3147. The final step was to prepare a spot on lawn assay using the indicator species: Lactococcus lactis subsp. cremoris HP.  The spot on lawn assay prepared for lacticin 3147 was a visual indicator of the strong antimicrobial effects of the bacteriocin. Ultimately, this highly effective bacteriocin, lacticin 3147, could be utilized in smaller  concentrations than current antibiotics, and thus shows great promise in the field of antibiotics. Further studies are being conducted to understand the interactions between the A1 and A2 components of lacticin 3147, including their synergistic effects.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

Inductive Effect as a Universal Concept to Design Efficient Catalysts for CO2 Electrochemical Reduction: Electronegativity Difference Makes Difference

2021 ◽  
Author(s):  
Huihuang Chen ◽  
Weng Fu ◽  
Zhigang Geng ◽  
Jie Zeng ◽  
Bo Yang
Keyword(s):  
Electrochemical Reduction ◽  
Energy Supply ◽  
Environmental Remediation ◽  
High Performance ◽  
Inductive Effect ◽  
Great Promise ◽  
Electronegativity Difference

CO2 electrochemical reduction (CO2ER) into valuable chemical feedstocks holds great promise for energy supply and environmental remediation but remains a challenge due to the lack of high-performance electrocatalysts. Inductive effect,...

scholarly journals Effects of Molecular Weight of Functionalized Liquid Butadiene Rubber as a Processing Aid on the Properties of SSBR/Silica Compounds

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 850
Author(s):  
Donghyuk Kim ◽  
Byungkyu Ahn ◽  
Kihyun Kim ◽  
JongYeop Lee ◽  
Il Jin Kim ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Anionic Polymerization ◽  
High Performance ◽  
Crosslink Density ◽  
Functional Group ◽  
Vital Role ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Mooney Viscosity ◽  
Silica Dispersion

Liquid butadiene rubber (LqBR) which used as a processing aid play a vital role in the manufacturing of high-performance tire tread compounds. However, the studies on the effect of molecular weight, microstructure, and functionalization of LqBR on the properties of compounds are still insufficient. In this study, non-functionalized and center-functionalized liquid butadiene rubbers (N-LqBR and C-LqBR modified with ethoxysilyl group, respectively) were synthesized with low vinyl content and different molecular weights using anionic polymerization. In addition, LqBR was added to the silica-filled SSBR compounds as an alternative to treated distillate aromatic extract (TDAE) oil, and the effect of molecular weight and functionalization on the properties of the silica-filled SSBR compound was examined. C-LqBR showed a low Payne effect and Mooney viscosity because of improved silica dispersion due to the ethoxysilyl functional group. Furthermore, C-LqBR showed an increased crosslink density, improved mechanical properties, and reduced organic matter extraction compared to the N-LqBR compound. LqBR reduced the glass transition temperature (Tg) of the compound significantly, thereby improving snow traction and abrasion resistance compared to TDAE oil. Furthermore, the energy loss characteristics revealed that the hysteresis loss attributable to the free chain ends of LqBR was dominant.

Building sponge-like robust architectures of CNT–graphene–Si composites with enhanced rate and cycling performance for lithium-ion batteries

2015 ◽  
Vol 3 (7) ◽  
pp. 3962-3967 ◽  
Author(s):  
Xiaolei Wang ◽  
Ge Li ◽  
Fathy M. Hassan ◽  
Matthew Li ◽  
Kun Feng ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Materials ◽  
High Performance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Cycling Stability ◽  
Great Promise ◽  
Practical Applications ◽  
Excellent Cycling Stability

High-performance robust CNT–graphene–Si composites are designed as anode materials with enhanced rate capability and excellent cycling stability for lithium-ion batteries. Such an improvement is mainly attributed to the robust sponge-like architecture, which holds great promise in future practical applications.

scholarly journals TAIJI: approaching experimental replicates-level accuracy for drug synergy prediction

2018 ◽  
Vol 35 (13) ◽  
pp. 2338-2339 ◽  
Author(s):  
Hongyang Li ◽  
Shuai Hu ◽  
Nouri Neamati ◽  
Yuanfang Guan
Keyword(s):  
Drug Combination ◽  
High Performance ◽  
Synergistic Effects ◽  
Field Performance ◽  
Supplementary Information ◽  
Drug Synergism ◽  
High Throughput Drug Screening ◽  
Current State ◽  
Candidate Drug ◽  
High Prediction

Abstract Motivation Combination therapy is widely used in cancer treatment to overcome drug resistance. High-throughput drug screening is the standard approach to study the drug combination effects, yet it becomes impractical when the number of drugs under consideration is large. Therefore, accurate and fast computational tools for predicting drug synergistic effects are needed to guide experimental design for developing candidate drug pairs. Results Here, we present TAIJI, a high-performance software for fast and accurate prediction of drug synergism. It is based on the winning algorithm in the AstraZeneca-Sanger Drug Combination Prediction DREAM Challenge, which is a unique platform to unbiasedly evaluate the performance of current state-of-the-art methods, and includes 160 team-based submission methods. When tested across a broad spectrum of 85 different cancer cell lines and 1089 drug combinations, TAIJI achieved a high prediction correlation (0.53), approaching the accuracy level of experimental replicates (0.56). The runtime is at the scale of minutes to achieve this state-of-the-field performance. Availability and implementation TAIJI is freely available on GitHub (https://github.com/GuanLab/TAIJI). It is functional with built-in Perl and Python. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals An Exploration on the Suitability of Airborne Carbonyl Compounds Analysis in relation to Differences in Instrumentation (GC-MS versus HPLC-UV) and Standard Phases (Gas versus Liquid)

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ki-Hyun Kim ◽  
Jan E. Szulejko ◽  
Yong-Hyun Kim ◽  
Min-Hee Lee
Keyword(s):  
Carbonyl Compounds ◽  
High Performance ◽  
Response Factor ◽  
Method Detection Limit ◽  
Uv Detector ◽  
Molecular Weights ◽  
Recovery Pattern ◽  
Experimental Bias ◽  
Performance Figure ◽  
Dnph Derivatization

The relative performance figure of merits was investigated for the two most common analytical methods employed for carbonyl compounds (CC), for example, between high performance liquid chromatography (HPLC)-UV detector (with 2,4-dinitrophenylhydrazine (DNPH) derivatization) and thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) (without derivatization). To this end, the suitability of each method is assessed by computing the relative recovery (RR) between the gas- and liquid-phase standards containing a suite of CC such as formaldehyde (FA), acetaldehyde (AA), propionaldehyde (PA), butyraldehyde (BA), isovaleraldehyde (IA), and valeraldehyde (VA) along with benzene (B) as a recovery reference for the GC method. The results confirm that a TD-GC-MS is advantageous to attain the maximum recovery for the heavier CCs (i.e., with molecular weights (MW) above BA−MW ≥ 74). On the other hand, the HPLC-UV is favorable for the lighter CCs (like FA and AA) with the least bias. Such compound-specific responses for each platform are validated by relative ordering of CCs as a function of response factor (RF), method detection limit (MDL), and recovery pattern. It is thus desirable to understand the advantages and limitations of each method to attain the CC data with the least experimental bias.

scholarly journals Synergistic interaction of renewable nipagin and eugenol for high performance aromatic copoly(ether ester) materials

2021 ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao
Keyword(s):  
High Performance ◽  
Synergistic Interaction ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Naturally Occurring ◽  
Ether Ester

Abstract Naturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) materials. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11-xE1x and PHN11-xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggest that properties of such kind of poly(ether ester)s can be finely tuned by the relative content of two components. Synergistic interaction of two structurally distinctive parts endows the materials with high performance.

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