scholarly journals A rapid and simple method for routine determination of antibiotic sensitivity to biofilm populations of Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Dhammika Leshan Wannigama ◽  
Cameron Hurst ◽  
Parichart Hongsing ◽  
Lachlan Pearson ◽  
Thammakorn Saethang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Screening Method ◽  
Antibiotic Sensitivity ◽  
Cost Effective ◽  
Response Patterns ◽  
Simple Method ◽  
Planktonic Bacteria ◽  
Antibiotic Response ◽  
The Impact

Abstract Treatment of infections of Pseudomonas aeruginosa forming biofilms after antimicrobial testing on planktonic bacteria can result in substantial failure. Therefore, we offer a robust and simple experimental platform to test the impact of antimicrobials on biofilms. Antibiotic response patterns varied uniquely within biofilm formation capacity and minimal biofilm eradication concentrations (MBECs) has a significantly better discriminatory power than minimum inhibitory concentrations (MICs) to differentiate the overall efficiency of antibiotics to eradicate biofilm. Our resazurin-based 96-well-plate platform is able to emulate bacterial responses to antibiotics under biofilm conditions in a fast, simple, and cost-effective screening method adaptable to automation, and warrants trials in the clinic.

A rapid and simple method for routine determination of antibiotic sensitivity to biofilm populations of Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Dhammika Leshan Wannigama ◽  
Cameron Hurst ◽  
Parichart Hongsing ◽  
Lachlan Pearson ◽  
Thammakorn Saethang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Screening Method ◽  
Antibiotic Sensitivity ◽  
Cost Effective ◽  
Response Patterns ◽  
Simple Method ◽  
Planktonic Bacteria ◽  
Antibiotic Response ◽  
The Impact

Abstract Treatment of infections of Pseudomonas aeruginosa forming biofilms after antimicrobial testing on planktonic bacteria can result in substantial failure. Therefore, we offer a robust and simple experimental platform to test the impact of antimicrobials on biofilms. Antibiotic response patterns varied uniquely within biofilm formation capacity and minimal biofilm eradication concentrations (MBECs) has a significantly better discriminatory power than minimum inhibitory concentrations (MICs) to differentiate the overall efficiency of antibiotics to eradicate biofilm. Our resazurin-based 96-well-plate platform is able to emulate bacterial responses to antibiotics under biofilm conditions in a fast, simple, and cost-effective screening method adaptable to automation, and warrants trials in the clinic.

scholarly journals A rapid and simple method for routine determination of antibiotic sensitivity to biofilm populations of Pseudomonas aeruginosa

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Dhammika Leshan Wannigama ◽  
Cameron Hurst ◽  
Parichart Hongsing ◽  
Lachlan Pearson ◽  
Thammakorn Saethang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Sensitivity ◽  
Simple Method

scholarly journals Rheometer enabled study of cartilage frequency-dependent properties

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stefano Perni ◽  
Polina Prokopovich
Keyword(s):  
Applied Load ◽  
Cost Effective ◽  
Constant Load ◽  
Hydraulic Permeability ◽  
Frequency Dependent ◽  
Shear Moduli ◽  
Tissue Replacement ◽  
Cost Effective Approach ◽  
The Impact

AbstractDespite the well-established dependence of cartilage mechanical properties on the frequency of the applied load, most research in the field is carried out in either load-free or constant load conditions because of the complexity of the equipment required for the determination of time-dependent properties. These simpler analyses provide a limited representation of cartilage properties thus greatly reducing the impact of the information gathered hindering the understanding of the mechanisms involved in this tissue replacement, development and pathology. More complex techniques could represent better investigative methods, but their uptake in cartilage research is limited by the highly specialised training required and cost of the equipment. There is, therefore, a clear need for alternative experimental approaches to cartilage testing to be deployed in research and clinical settings using more user-friendly and financial accessible devices. Frequency dependent material properties can be determined through rheometry that is an easy to use requiring a relatively inexpensive device; we present how a commercial rheometer can be adapted to determine the viscoelastic properties of articular cartilage. Frequency-sweep tests were run at various applied normal loads on immature, mature and trypsinased (as model of osteoarthritis) cartilage samples to determine the dynamic shear moduli (G*, G′ G″) of the tissues. Moduli increased with increasing frequency and applied load; mature cartilage had generally the highest moduli and GAG depleted samples the lowest. Hydraulic permeability (KH) was estimated from the rheological data and decreased with applied load; GAG depleted cartilage exhibited higher hydraulic permeability than either immature or mature tissues. The rheometer-based methodology developed was validated by the close comparison of the rheometer-obtained cartilage characteristics (G*, G′, G″, KH) with results obtained with more complex testing techniques available in literature. Rheometry is relatively simpler and does not require highly capital intensive machinery and staff training is more accessible; thus the use of a rheometer would represent a cost-effective approach for the determination of frequency-dependent properties of cartilage for more comprehensive and impactful results for both healthcare professional and R&D.

scholarly journals A Simple Method to Map Groundwater Depth and Water Quality for Leogane, Haiti and Elsewhere

2021 ◽  
Vol 16 (1) ◽  
pp. 1-19
Author(s):  
Michael Edward Kalinski ◽  
Nicholas Duda ◽  
Herby Lissade ◽  
Harry Donaghy
Keyword(s):  
Water Quality ◽  
Water Table ◽  
Cost Effective ◽  
Groundwater Depth ◽  
Simple Method ◽  
Deep Aquifers ◽  
Water Wells ◽  
Effective Manner ◽  
System 2 ◽  
The Impact

In the aftermath of the January 2010 Haiti Earthquake, the streets of downtown Leogane were paved to mitigate waterborne disease using humanitarian relief funds. After paving, many of the shallow water wells in Leogane dried up. It was believed that the new pavement disrupted groundwater recharge and negatively impacted the wells. Therefore, a project was performed to assess groundwater conditions in a cost-effective manner using a rapid, inexpensive, non-intrusive geophysical approach. The scope of the project included 1) surveying the new pavement system, 2) surveying water wells in Leogane, 3) testing the well water for coliforms, 4) performing geophysical DC resistivity testing to map groundwater depth and 5) developing a groundwater map to assess the impact of the pavement on the water table. As a result of this project, it could not be concluded that the new pavement was a factor in the groundwater fluctuations observed in the water wells in Leogane. It is more likely that some of the drop in the water table was due to the earthquake itself and some of it was caused by seasonal fluctuations in the water table. It was also observed that all the water wells that extract water from shallow (less than 6 m deep) aquifers in Leogane contain coliforms due to their proximity to household latrines, although a second deeper aquifer was identified and found to be coliform-free. With respect to broader impact, this methodology represents a relatively simple approach to mapping groundwater and assessing water quality that can be easily applied to other communities in the developing world to guide their efforts to develop and manage groundwater.

scholarly journals Half-Cell State of Charge Monitoring for Determination of Crossover in VRFB—Considerations and Results Concerning Crossover Direction and Amount

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 232
Author(s):  
Theresa Haisch ◽  
Hyunjoon Ji ◽  
Lucas Holtz ◽  
Thorsten Struckmann ◽  
Claudia Weidlich
Keyword(s):  
Open Circuit ◽  
State Of Charge ◽  
Anion Exchange Membranes ◽  
Half Cell ◽  
Cell Potential ◽  
Simple Method ◽  
Flow Batteries ◽  
The Impact ◽  
Positive Half

Membranes play a crucial role in efficiency and longevity of flow batteries. Vanadium flow batteries suffer self-discharge and capacity fading due to crossover of electrolyte components through the membrane from one battery half-cell to the other. We consider the impact of vanadium species crossing ion exchange membranes on state of charge of the battery and we present a simple method to determine crossoverll open circuit potential measurements. State of s. State of charge for the negative and positive half-cell is simulated based on assumptions and simplifications for cation and anion exchange membranes and different crossover parameters. We introduce a crossover index “IndXovr” which enables the determination of crossover direction from state of charge data for the negative and positive half-cell and therewith identification of the half-cell in which predominant self-discharge occurs. Furthermore IndXovr allows statements on crossover amount in dependence on state of operation. Simulated case studies are compared to experimental state of charge values estimated from half-cell potential measurements. Our results reveal that half-cell potential monitoring respectively half-cell SOC estimation, is a simple and suitable tool for the identification of crossover direction and relative amount of crossover in VFB.

Screening of sulfonamides in waters based on miniaturized solid phase extraction and microplate spectrophotometric detection

2018 ◽  
Vol 10 (7) ◽  
pp. 690-696 ◽  
Author(s):  
Patrícia S. Peixoto ◽  
Ildikó V. Tóth ◽  
Sandia Machado ◽  
Luisa Barreiros ◽  
Ana Machado ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Screening Method ◽  
Cost Effective ◽  
Phase Extraction ◽  
Spectrophotometric Detection ◽  
Effective Screening

A simple and cost-effective screening method for determination of sulfonamides in water is proposed.

scholarly journals HPLC method development for determination of metoprolol, telmisartan and cilnidipine simultaneously using response surface design

2021 ◽  
Vol 12 (1) ◽  
pp. 602-610
Author(s):  
Jayaseelan S ◽  
Kannappan N ◽  
Ganesan V
Keyword(s):  
Quantitative Methods ◽  
Method Development ◽  
Desirability Function ◽  
Cost Effective ◽  
Drug Dosage ◽  
Hplc Method ◽  
Good Resolution ◽  
Simple Method ◽  
Short Run

The development of an HPLC method for determination of Metoprolol, Telmisartan and Cilnidipine simultaneously in additional dosage was not published or reported up till date. The main aim of our study was to design a simultaneous and multiple response optimizations using the Derringer's desirability function in order to estimate Metoprolol, Telmisartan and Cilnidipine in pharmaceutical and bulk drug dosage form by HPLC method with experiment central compositive design (CCD) protocol for the quantitative methods analysis and also for validation of the procedure that is developed as per ICH regulations. An innovative RP-HPLC method had been designed for the estimation of Metoprolol, Telmisartan and Cilnidipine simultaneously in formulation using central composite design. Three factors were investigated and determined as significant when compared to the interaction and quadratic effect of the samples that CCD along with the response of the surface methodology. The developed method produced a good resolution of the drugs with a very short run time of 7.5 min. It was also validated according to ICH guidelines. It was recognized as novel and simple method that is accurate and cost-effective. So the proposed method fits best in the assaying routine of Metoprolol, Telmisartan and Cilnidipine in any formulations produced by quality control laboratories.

The sensitivity determination of energetic materials from laser spark spectrometry based on physical-parameter-corrected statistical methods

2021 ◽  
Author(s):  
Xianshuang Wang ◽  
Junfeng Wang ◽  
Ying Fu ◽  
Ruibin Liu ◽  
Yage He ◽  
...  
Keyword(s):  
Physical Parameter ◽  
Statistical Methods ◽  
Energetic Materials ◽  
Simple Method ◽  
Laser Spark ◽  
The Impact

A simple method combining the impact of various factors on sensitivity is developed to determine various sensitivities via laser spark spectrometry with the consumption of only several milligrams of EM, rather than via macro-detonation testing.

MULTICRITERIAL SUSTAINABILITY ASSESSMENT OF RESIDENTIAL BUILDINGS

2009 ◽  
Vol 15 (4) ◽  
pp. 612-630 ◽  
Author(s):  
Marjana Šijanec Zavrl ◽  
Roko Žarnić ◽  
Jana Šelih
Keyword(s):  
Input Data ◽  
Sustainability Assessment ◽  
Residential Buildings ◽  
Residential Building ◽  
Assessment Method ◽  
Local Context ◽  
Second Step ◽  
Simple Method ◽  
The Impact

A simple method for the assessment of sustainability of a residential building is proposed. The method consists of two steps. First, areas that influence sustainability level of the building (e.g. building architecture, design, in‐built materials) are identified. For each area, several elements and corresponding indicators are determined. Depending on their nature, the indicators are expressed either in quantitative or qualitative terms. The impact areas and their corresponding elements influence all three aspects of sustainability. In the second step, the indicators are aggregated according to their influence on individual sustainability aspects. Special attention is placed to the determination of weights assigned to the indicators in order to make the assessment method relevant in the local context. Initially, the consensus‐based method within the research team was used as a technique for aggregated indicators’ weighting. Later, the open discourses among the developers and stakeholders, as well as surveys, were employed to determine the aggregated indicators’ weights. The proposed method is applied to a selected sample building, and the analysis of the results is carried out. The results obtained show that the completeness and reliability of the input data is crucial for the reliability of the proposed assessment method. Subjectivity in evaluators’ judgments required to score some indicators needs to be reduced by introducing adequate training of the assessors. The feedback from the potential users shows that the method has a potential for wider future implementation in practice. Santrauka Straipsnyje siūlomas paprastas gyvenamųjų namų darnos vertinimo metodas. Šiuo metodu skaičiuojama dviem etapais. Pirmuoju etapu nustatomi kriterijai, darantys įtaką pastato darnos lygiui (pavyzdžiui, pastato architektūra, konstrukcija, medžiagos). Nustatomi keli kiekvieną kriterijų apibūdinantys rodikliai. Priklausomai nuo pobūdžio jie gali būti kiekybiniai arba kokybiniai ir gali apibūdinti visus tris darnos aspektus. Antruoju etapu rodikliai sugrupuojami pagal jų įtaką atskiriems darnos aspektams. Ypatingas dėmesys skiriamas rodiklių reikšmingumų nustatymui. Tai vertinimo metodą daro tinkamą konkrečioms sąlygoms. Rodiklių reikšmingumai nustatomi grupės ekspertų nuomonių sutarimo metodu. Vėliau reikšmingumai tikslinami diskusijoje tarp susinteresuotų grupių narių. Pasiūlytas metodas pritaikytas pasirinktam tipiniam pastatui, atlikta gautų rezultatų analizė. Rezultatai atskleidė, jog pradinių duomenų išsamumas ir tikrumas daro lemiamą įtaką pasiūlyto vertinimo metodo patikimumui. Tinkamai apmokant vertintojus galima sumažinti kai kurių rodiklių vertinimo subjektyvumą. Potencialių vartotojų reakcija rodo, kad ateityje šis metodas gali būti plačiai taikomas.

scholarly journals Radical Stabilization Energies for Enzyme Engineering – Tackling the Substrate Scope of the Radical Enzyme QueE

2018 ◽  
Author(s):  
Christian Suess ◽  
Floriane Martins ◽  
Anna Croft ◽  
Christof Jaeger
Keyword(s):  
Screening Method ◽  
Cost Effective ◽  
Md Simulations ◽  
Enzyme Engineering ◽  
Radical Intermediates ◽  
Stabilization Energies ◽  
Effective Assessment ◽  
Semi Empirical ◽  
The Impact ◽  
Radical Enzymes

Experimental assessment of the reaction mechanisms and profiles of radical enzymes can be severely challenging due to the reactive nature of the intermediates, and sensitivity of cofactors such as iron sulfur clusters. Here we present an enzyme-directed computational methodology for the assessment of thermodynamic reaction profiles and screening for radical stabilization energies (RSEs) for the assessment of catalytic turnovers in radical enzymes. We have applied this new screening method to the radical SAM enzyme CPH4 synthase (QueE), following a detailed molecular dynamics (MD) analysis that clarifies the role of both specific enzyme residues and bound Mg2+, Ca2+ or Na+. The MD simulations provided the basis for a statistical approach to sample different conformational outcomes. RSE calculation at the M06-2X/6-31+G* level of theory provided the most computationally cost-effective assessment of enzyme-based energies, facilitated by an initial triage using semi-empirical methods. The impact of intermolecular interactions on RSE was clearly established and application to the assessment of potential alternative substrates (focusing on radical clock type rearrangements) proposes a selection of carbon-substituted analogues that would react to afford cyclopropylcarbinyl radical intermediates, as candidates for catalytic turnover by QueE.

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