scholarly journals A Facile Colorimetric Method For Ultra-Rapid And Sensitive Detection of Copper Ions In Water

2021 ◽  
Author(s):  
Lei Chen ◽  
Yan Li ◽  
Ping Sun ◽  
Hualin Chen ◽  
He Li ◽  
...  
Keyword(s):  
Color Change ◽  
Copper Ions ◽  
Colorimetric Method ◽  
Ethanol Solution ◽  
Sensitive Detection ◽  
World Health ◽  
Great Promise ◽  
Experimental Conditions ◽  
Interesting Phenomenon ◽  
Health Organization

Abstract It is of great meaning to develop a facile, reliable and sensitive method to detect copper ions in water. In the study, a facile method has been developed for rapid and sensitive detection of Cu2+. An interesting phenomenon has been observed that 3,3',5,5'-tetramethylbenzidine (TMB) ethanol solution can be extremely fast passed from colorless to yellow once Cu2+ ions are added. It easily occurs to us that Cu2+ can be quantitatively determined via the absorbance at 904 nm of the color changed TMB solution. More importantly, some specific anions (Cl- , Br- ) can significantly enhance the absorption intensity. Under the optimized experimental conditions, this method exhibits a good linear response range for Cu2+ from 0.5 to 100 μM, with the detection limit of 93 nM. Moreover, the possible detection principle has been explored. It is worth mentioning that the color change can be clearly observed by naked eyes for the detection of 1 μM Cu2+, which is far below the threshold limit of Cu2+ in drinking water suggested by World Health Organization. It means that this method possess great promise for on-site Cu2+ detection.

scholarly journals Colorimetric detection of Cu2+ based on the formation of peptide–copper complexes on silver nanoparticle surfaces

2018 ◽  
Vol 9 ◽  
pp. 1414-1422 ◽  
Author(s):  
Gajanan Sampatrao Ghodake ◽  
Surendra Krishna Shinde ◽  
Rijuta Ganesh Saratale ◽  
Avinash Ashok Kadam ◽  
Ganesh Dattatraya Saratale ◽  
...  
Keyword(s):  
Copper Complexes ◽  
Color Change ◽  
Copper Ions ◽  
Colorimetric Detection ◽  
Colorimetric Method ◽  
World Health ◽  
Safe Limit ◽  
Distinct Color ◽  
Health Organization ◽  
Good Detection Limit

We developed a colorimetric method for the rapid detection of copper ions (Cu2+) in aqueous solution. The detection of Cu2+ is based on coordination reactions of Cu2+ with casein peptide-functionalized silver nanoparticles (AgNPs), leading to a distinct color change of the solution from yellow to red. The developed method has a good detection limit of about 0.16 µM Cu2+ using 0.05 mL of AgNPs stock solution and a linearity in the range of 0.08–1.44 µM Cu2+ with a correlation coefficient of R2 = 0.973. The developed method is a useful tool for the detection of Cu2+ ions. Furthermore, it can be used for monitoring Cu2+ in water at concentrations below the safe limit for drinking water set by the World Health Organization.

scholarly journals A Sensitive Near-Infrared Fluorescent Probe for Detecting Heavy Metal Ag+ in Water Samples

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 247 ◽  
Author(s):  
Yawen Zhang ◽  
Aiying Ye ◽  
Yuewei Yao ◽  
Cheng Yao
Keyword(s):  
Fluorescent Probe ◽  
Water Samples ◽  
Near Infrared ◽  
Color Change ◽  
World Health ◽  
Naked Eye ◽  
Real Water Samples ◽  
Frequent Use ◽  
The World ◽  
Health Organization

Silver is a common catalyst in industrial production, and the frequent use of Ag+ can cause water pollution. Thus, the detection of Ag+ in the environment is necessary to determine the level of pollution from silver. In this work, we designed a new, highly selective near-infrared (NIR) fluorescent probe QCy to detect Ag+. The probe exhibits “turn-off” fluorescence quenching responses at 760 nm towards Ag+ over other relevant cations, with outstanding sensitivity and a low detection limit (0.03 µM), which is considerably lower than the standard of the World Health Organization (WHO) for drinking water (0.9 µM). Meanwhile, QCy showed a very good linearity at a low concentration of Ag+ with a ‘naked eye’ visible color change of solution from blue to red. The probe has been applied successfully for the detection of Ag+ in real water samples.

scholarly journals Multimeric single-domain antibody complexes protect against bunyavirus infections

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Paul J Wichgers Schreur ◽  
Sandra van de Water ◽  
Michiel Harmsen ◽  
Erick Bermúdez-Méndez ◽  
Dubravka Drabek ◽  
...  
Keyword(s):  
Rift Valley Fever Virus ◽  
Building Blocks ◽  
Single Domain ◽  
World Health ◽  
Great Promise ◽  
Single Domain Antibody ◽  
Valley Fever ◽  
Antiviral Therapies ◽  
Single Domain Antibodies ◽  
Health Organization

The World Health Organization has included three bunyaviruses posing an increasing threat to human health on the Blueprint list of viruses likely to cause major epidemics and for which no, or insufficient countermeasures exist. Here, we describe a broadly applicable strategy, based on llama-derived single-domain antibodies (VHHs), for the development of bunyavirus biotherapeutics. The method was validated using the zoonotic Rift Valley fever virus (RVFV) and Schmallenberg virus (SBV), an emerging pathogen of ruminants, as model pathogens. VHH building blocks were assembled into highly potent neutralizing complexes using bacterial superglue technology. The multimeric complexes were shown to reduce and prevent virus-induced morbidity and mortality in mice upon prophylactic administration. Bispecific molecules engineered to present two different VHHs fused to an Fc domain were further shown to be effective upon therapeutic administration. The presented VHH-based technology holds great promise for the development of bunyavirus antiviral therapies.

Water safety planning: adapting the existing approach to community-managed systems in rural Nepal

2013 ◽  
Vol 3 (3) ◽  
pp. 392-401 ◽  
Author(s):  
Dani Barrington ◽  
Kathryn Fuller ◽  
Andrew McMillan
Keyword(s):  
Water Supply ◽  
Community Education ◽  
World Health ◽  
Great Promise ◽  
Water Supply Systems ◽  
Water Safety ◽  
Hazard Management ◽  
Sanitation And Hygiene ◽  
Health Organization ◽  
Rural Nepal

Water Safety Plans (WSPs) improve the quality and secure the quantity of drinking water supplies, and hence improve public health outcomes. In developing countries such as Nepal, thousands of residents die each year as a result of poor water, sanitation and hygiene (WASH) services and WSPs show great promise for improving both health and livelihoods. The Nepali Non-Governmental Organisation Nepal Water for Health (NEWAH) has been working in partnership with Engineers Without Borders Australia and WaterAid Nepal to develop a WSP methodology suited to rural, community-managed water supply systems. Three pilot projects were undertaken incorporating community-based hazard management into the standard World Health Organization and Nepali Department of Water Supply and Sewerage WSP approaches. The successes and challenges of these pilots were assessed, and it was determined that community education, behaviour change, and the distribution of simplified WSP documentation to households and managers were essential to implementing successful WSPs within this context. This new WSP methodology is currently being mainstreamed throughout all of NEWAH's WASH projects in rural Nepal, as well as being shared with the wider Nepali WASH sector.

scholarly journals Does each bead count? A reduced-cost approach for recovering waterborne protozoa from challenge water using immunomagnetic separation

2021 ◽  
Author(s):  
Natália de Melo Nasser Fava ◽  
Kamila Jessie Sammarro Silva ◽  
William John Snelling ◽  
Nigel George Ternan ◽  
James Stephen Gerard Dooley ◽  
...  
Keyword(s):  
Immunofluorescence Microscopy ◽  
Giardia Duodenalis ◽  
Immunomagnetic Separation ◽  
World Health ◽  
Waterborne Diseases ◽  
Recovery Efficiency ◽  
Analytical Quality ◽  
Experimental Conditions ◽  
Concentration Step ◽  
Health Organization

Abstract Giardia duodenalis and Cryptosporidium spp. are two of the most prominent aetiological agents of waterborne diseases. Therefore, efficient and affordable methodologies for identifying and quantifying these parasites in water are increasingly necessary. USEPA Method 1623.1 is a widely used and validated protocol for detecting these parasites in water samples. It consists of a concentration step, followed by parasite purification and visualization by immunofluorescence microscopy. Although efficient, this method has a high cost particularly due to the immunomagnetic separation (IMS) step, which is most needed with complex and highly contaminated samples. Based on this, the present study aimed to determine whether it is possible to maintain the efficiency of Method 1623.1 while reducing the amount of beads per reaction, using as a matrix the challenge water recommended by the World Health Organization. As for Giardia cysts, a satisfactory recovery efficiency (RE) was obtained using 50% less IMS beads. This was evaluated both with a commercial cyst suspension (56.1% recovery) and an analytical quality assessment (47.5% recovery). Although RE rates obtained for Cryptosporidium parvum did not meet Method 1623.1 criteria in any of the experimental conditions tested, results presented in this paper indicated the relevance of the described adaptations, even in challenge water.

Gemini-Mediated Self-Disinfecting Surfaces to Address Contact Transmission of Infectious Diseases

2021 ◽  
Author(s):  
Kollbe Ahn Ando ◽  
Roscoe Lisntadt ◽  
Jinsoo Ahn ◽  
Minju Kim
Keyword(s):  
Infectious Diseases ◽  
Quaternary Ammonium ◽  
Gemini Surfactants ◽  
Antimicrobial Properties ◽  
World Health ◽  
Comparable Efficacy ◽  
Great Promise ◽  
Contact Transmission ◽  
Comparable Activity ◽  
Health Organization

According to both the Center for Disease Control (CDC) and the World Health Organization (WHO), contact-transmission (contact between host tissues and a contaminated surface) is the primary transmission route of infectious diseases worldwide. Usually this is mitigated by adherence to a schedule of repeated regular sanitization, yet this approach is inherently limited by sanitization frequency; conventional disinfectants/methods are only germicidal during the period of application, and surfaces are easily re-contaminated in the interim between cleanings. One solution to this problem is to use agents/coatings that impart self-disinfecting properties onto the existing surfaces such that they display sustained virucidal/antimicrobial properties against pathogens that settle upon them. Quaternary-ammonium organosilicon compounds are ideal candidates to achieve this; cationic surfactants are safe and well-established surface disinfectants while organosilanes are used broadly to form durable coatings with altered surface properties on many different materials. Despite their potential to circumvent disadvantages of traditional disinfection methods, extant commercially available quaternary-ammonium silanes do not display comparable efficacy to standard surface disinfectants, nor have their respective coatings been demonstrated to meet the Environmental Protection Agency’s guidelines for residual/extended efficacy. Inspired by powerful surface activity of double-headed “gemini” surfactants, here we present gemini-diquaternary (GQ) silanes with robust residual germicidal efficacy on various surfaces by incorporating a second cationic “head” to the structure of an conventional mono-quaternary-ammonium silane. Aqueous solutions of GQs were tested in suspension- and surface-antimicrobial assays against an array of pathogens, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). GQ performance was benchmarked against the common disinfectants, ethanol, hydrogen peroxide and hypochlorite, as well as against a common antimicrobial mono-quaternary (MQ) silane. Solutions of GQ silanes were efficacious when used for immediate disinfection, showing comparable activity to common disinfectants (>106 fold reduction in 15 seconds). Additionally GQ solutions were demonstrated to impart durable self-disinfecting properties to a variety of porous and nonporous surfaces, efficacious after repeated cycles of abrasion and repeated contaminations, and with superior coating ability and activity (>108 higher activity) than that of the popular MQ silane. GQ solutions as surface treatments show great promise to overcome the limitations of traditional disinfectants in preventing the spread of infectious diseases.

scholarly journals MON-LB114 CGM in Cystic Fibrosis Patients to Predict Cystic Fibrosis-Related Diabetes Onset

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Mariana Zorron Mei Hsia Pu ◽  
José D Ribeiro ◽  
André M Morcillo ◽  
Aline C Gonçalves ◽  
Antonio F Ribeiro ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Colorimetric Method ◽  
Solid Organ Transplantation ◽  
Forced Expiratory Volume ◽  
World Health ◽  
Solid Organ ◽  
Early Diabetes ◽  
Diabetes Onset ◽  
Health Organization

Abstract Background: Therapeutic progress and improvement on resources enabled the emergence of new comorbidities in cystic fibrosis (CF), such as cystic fibrosis-related diabetes (CFRD). About 20% of adolescents and 40-50% of adults are affected. CFRD and glucose intolerance reduce life expectancy in this population, highlighting the importance of early diagnosis and treatment. Up to 15% of CF patients have hypoglycemia during OGTT and its etiology remains unclear. Some authors associate hypoglycemia with CFRD onset, while others do not agree with this association. Objective: To determine whether abnormal CGM (hypo/hyperglycemia) can predict CFRD onset, pulmonary function and BMI decline in CF patients. Methods: Prospective single center study. All CF patients between 10-19yo from our outpatient clinic were screened for CFRD through OGTT following the World Health Organization (WHO) protocol. The enzymatic colorimetric method was used to classify them as per the ADA. Non-diabetic CF patients performed 3-day CGM, forced expiratory volume in the first second (FEV1), BMI and OGTT. All tests except for CGM were then reassessed after a long follow-up. The WHO’s 2006 curve was used to calculate the z scores for individuals ≤19yo and WHO cut-off values for >19yo. Oral corticoid use during data collection, pregnancy and solid organ transplantation were exclusion criteria. Results: Thirty-nine patients were recruited and 34 completed an average of 3.1 years (±0.51) follow-up. No clinical or laboratory variables could predict diabetes progression or hypoglycemic events. The cohort had an increase in mean BMI (17.80±3.65 vs 18.36±3.49; p=0.025) and a reduction in mean FEV1 (66.91±25.79% vs 56.32±29.57%; p=0.001) between the two evaluations. Patients who developed diabetes showed statistically significant worse FEV1 in the end of the follow-up (22.67±5 vs 59.58±28.9; p=0.041), and lower BMI at both start (14.37±1.23 vs 18.13±3.65; p=0.049) and end (14.81±0.66 vs 18.71±3.46; p=0.029) of follow-up. A logistic regression of the effect of time adjusted for independent variables for progression to CFRD was conducted. A higher possibility of evolution among participants with IGT (odds ratio [OR] 21.67; 95% confidence interval [CI] 7.03-67.36; p<0.01), and a lower possibility among participants with NGT (OR 1.84; 95% CI 1.06-3.19; p=0.031). Conclusion: CGM was not a useful tool to predict early diabetes onset in this population with the current cut-off values. However, the IGT group seems to be the riskiest group. The CF population has particular characteristics and may not have the same diagnostic criteria for DM as the non-CF population. More studies are necessary to determine the appropriate CGM cut-off values for CFRD.

DETERMINATION OF AMINOGLYCOSIDE ANTIBIOTICS BY A COLORIMETRIC METHOD BASED ON THE AGGREGATION OF GOLD NANOPARTICLES

NANO ◽  
2013 ◽  
Vol 08 (04) ◽  
pp. 1350037 ◽  
Author(s):  
RUIYONG WANG ◽  
SHUMIN FAN ◽  
RUIQIANG WANG ◽  
RUI WANG ◽  
HUANJING DOU ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Incubation Time ◽  
Color Change ◽  
Limit Of Detection ◽  
Colorimetric Method ◽  
Aminoglycoside Antibiotics ◽  
Sensing Element ◽  
Experimental Conditions ◽  
Experimental Parameters

A sensitive and selective colorimetric biosensor for determination of gentamicin, amikacin and tobramycin was proposed with the unmodified gold nanoparticles (GNPs) as the sensing element. Gentamicin, amikacin and tobramycin can rapidly induce the aggregation of gold nanoparticles and is accompanied by a color change from red to blue. The concentration of gentamicin, amikacin and tobramycin can be determined by using UV-Vis spectrometer. The experimental parameters were optimized with regard to pH, incubation time and the concentration of the GNPs. Under optimal experimental conditions, the linear range of the colorimetric sensor for gentamicin/amikacin/tobramycin were 2.67–33.93 ng mL-1, 13.33–66.67 ng mL-1 and 20–180 ng mL-1, respectively. The corresponding limit of detection (3σ) was 0.354 ng mL-1, 0.999 ng mL-1 and 0.579 ng mL-1, respectively. This assay was simple and used to detect aminoglycoside antibiotics in milk and medicine products.

Endocrine Neoplasms of the Pancreas: Pathologic and Genetic Features

2009 ◽  
Vol 133 (3) ◽  
pp. 350-364 ◽  
Author(s):  
Paola Capelli ◽  
Guido Martignoni ◽  
Federica Pedica ◽  
Massimo Falconi ◽  
Davide Antonello ◽  
...  
Keyword(s):  
Significant Risk ◽  
World Health ◽  
Great Promise ◽  
Genetic Event ◽  
Primary Material ◽  
Genetic Features ◽  
Poorly Differentiated ◽  
Clinically Significant ◽  
Well Differentiated ◽  
Health Organization

Abstract Context.—Pancreatic endocrine neoplasms (PENs) are diagnostically challenging tumors whose natural history is largely unknown. Histopathology allows the distinction of 2 categories: poorly differentiated high-grade carcinomas and well-differentiated neoplasms. The latter include more than 90% of PENs whose clinical behavior varies from indolent to malignant and cannot be predicted by their morphology. Objectives.—To review the literature and report on additional primary material about the clinicopathologic features, classification, staging, grading, and genetic features of PENs. Data Sources.—Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institution. Conclusions.—The diagnosis of PEN is generally easy, but unusual features may induce misdiagnosis. Immunohistochemistry solves the issue, provided that the possibility of a PEN has been considered. Morphology allows the distinction of poorly differentiated aggressive carcinomas from well-differentiated neoplasms. The World Health Organization classification criteria allow for the discernment of the latter into neoplasms and carcinomas with either benign or uncertain behavior. The recently proposed staging and grading systems hold great promise for permitting a stratification of carcinomas into clinically significant risk categories. To date, inactivation of the MEN1 gene remains the only ascertained genetic event involved in PEN genesis. It is inactivated in roughly one-third of PENs. The degree of genomic instability correlates with the aggressiveness of the neoplasm. Gene silencing by promoter methylation has been advocated, but a formal demonstration of the involvement of specific genes is still lacking. Expression profiling studies are furnishing valuable lists of mRNAs and noncoding RNAs that may advance further the research to discover novel markers and/or therapeutic targets.

scholarly journals The Potential Use of Mesenchymal Stem Cells and Their Derived Exosomes as Immunomodulatory Agents for COVID-19 Patients

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Faisal A. Alzahrani ◽  
Islam M. Saadeldin ◽  
Abrar Ahmad ◽  
Dipak Kumar ◽  
Esam I. Azhar ◽  
...  
Keyword(s):  
Stem Cells ◽  
Clinical Trials ◽  
Mesenchymal Stem Cells ◽  
Therapeutic Potential ◽  
World Health ◽  
Inhalation Therapy ◽  
Great Promise ◽  
Allogenic Bone ◽  
Lung Injuries ◽  
Health Organization

A novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) causing lethal acute respiratory disease emerged in December 2019. The World Health Organization named this disease “COVID-19” and declared it a pandemic on March 11, 2020. Many studies have shown that mesenchymal stem cells (MSCs) and their exosomes (MSCs-Exo), which are isolated from allogenic bone marrow stem cells, significantly lower the risk of alveolar inflammation and other pathological conditions associated with distinct lung injuries. For example, in acute respiratory distress syndrome (ARDS) and pneumonia patients, MSCs-Exo and MSCs provide similar healing properties and some clinical trials have used cell-based inhalation therapy which show great promise. MSCs and MSCs-Exo have shown potential in clinical trials as a therapeutic tool for severely affected COVID-19 patients when compared to other cell-based therapies, which may face challenges like the cells’ sticking to the respiratory tract epithelia during administration. However, the use of MSCs or MSCs-Exo for treating COVID-19 should strictly adhere to the appropriate manufacturing practices, quality control measurements, preclinical safety and efficacy data, and the proper ethical regulations. This review highlights the available clinical trials that support the therapeutic potential of MSCs or MSCs-Exo in severely affected COVID-19 patients.

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