Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
1.
Sex Transm Infect ; 100(1): 39-44, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-37977653

RESUMEN

BACKGROUND: Sexual assault (SA) is a prevalent issue with enduring consequences. Post-SA medical care mainly focuses on injuries, sexually transmitted infection (STI) prevention and detection, as well as preventing unwanted pregnancies. Swift access to post-SA medical care is vital with sexual assault treatment units (SATUs) streamlining this care. The primary aim of our study is to report on post-SA care provided at the national SATU network in Ireland with a secondary aim of analysing factors associated with follow-up attendance for STI testing. METHODS: This is a retrospective cohort study of all acute attendances (<7 days from incident) at the national SATU network between 1 January 2017 to 31 December 2022. RESULTS: A total of 4159 acute cases presented during the study period. Emergency contraception (EC) was administered to 53.8% (n=1899/3529) of cases, while postexposure prophylaxis (PEP) for chlamydia was given in 75.1% (n=3124/4159) and for HIV in 11.0% (n=304/3387). Hepatitis B vaccination was initiated in 53.7% (n=2233/4159) of cases. 1.4% (n=59/4159) of the attendees were referred to an emergency department for the treatment of injuries. Follow-up appointments were scheduled for 75.8% (3151/4159) of acute cases. 71.6% (n=2257/3151) attended follow-up.Certain factors were found to correlate with a higher likelihood of attending follow-up appointments: adolescents (p<0.0001), concern about drug-facilitated SA (DFSA) (p=0.01), no consumption of recreational drugs before the incident (p<0.0001), alcohol consumption prior to the incident (p=0.01), and not reporting the crime to the police (p<0.001). However, gender (p=0.06) and the presence of injury at time of primary attendance (p=0.97) were not predictive of likelihood of follow-up attendance. CONCLUSION: This study demonstrates that EC, chlamydia PEP, HIV PEP and hepatitis B vaccination were all administered at SATU. A small proportion of attenders required emergency injury care. Factors influencing attendance at follow-up include age, drug use, alcohol use and police involvement, highlighting the need for tailored patient-centred support.


Asunto(s)
Infecciones por VIH , Hepatitis B , Delitos Sexuales , Enfermedades de Transmisión Sexual , Embarazo , Femenino , Adolescente , Humanos , Estudios Retrospectivos , Estudios de Seguimiento , Profilaxis Posexposición , Enfermedades de Transmisión Sexual/diagnóstico , Enfermedades de Transmisión Sexual/epidemiología , Enfermedades de Transmisión Sexual/prevención & control , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Hepatitis B/diagnóstico , Hepatitis B/epidemiología , Hepatitis B/prevención & control
2.
Vet Med Sci ; 9(6): 2576-2585, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37817453

RESUMEN

BACKGROUND: Gastrointestinal bleeding is a cause of anaemia in dogs. A reliable, non-invasive biomarker to differentiate gastrointestinal bleeding from other causes of anaemia would be advantageous to direct clinical decisions in anaemic patients. Plasma urea:creatinine ratio is an accepted biomarker of upper gastrointestinal bleeding in human medicine. OBJECTIVES: The objective of this study was to evaluate plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in a population of dogs with anaemia. METHODS: This was a prospective cross-sectional study of dogs with anaemia presenting to referral centres for the investigation of anaemia. Cases were categorised as having overt gastrointestinal bleeding (melena on presentation), occult gastrointestinal bleeding (historical and diagnostic findings consistent with gastrointestinal bleeding without melena at presentation) or anaemia of other cause (confident diagnosis other than gastrointestinal bleeding reached, normal diagnostic imaging of gastrointestinal tract). Urea:creatinine ratio at presentation was calculated by dividing urea (mg/dL) by creatinine (mg/dL). RESULTS: Ninety-five dogs were included. Plasma urea:creatinine ratio was not significantly different between dogs with overt or occult gastrointestinal bleeding or those with anaemia of other cause (median urea:creatinine ratio 25.8, 20.7 and 22.5, respectively). No significant difference in urea:creatinine ratio was found between dogs with upper and lower gastrointestinal bleeding (median urea:creatinine ratio 19.4 and 24.6, respectively). CONCLUSIONS: Plasma urea:creatinine ratio was not helpful in differentiating between dogs with anaemia resulting from gastrointestinal bleeding (overt or occult) and those with other causes of anaemia.


Asunto(s)
Anemia , Enfermedades de los Perros , Humanos , Perros , Animales , Melena/complicaciones , Melena/veterinaria , Creatinina , Estudios Prospectivos , Estudios Transversales , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/veterinaria , Urea , Anemia/diagnóstico , Anemia/veterinaria , Anemia/complicaciones , Biomarcadores , Enfermedades de los Perros/diagnóstico
4.
Front Pharmacol ; 12: 777804, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34916950

RESUMEN

The medicinal use of Cannabis sativa L. can be traced back thousands of years to ancient China and Egypt. While marijuana has recently shown promise in managing chronic pain and nausea, scientific investigation of cannabis has been restricted due its classification as a schedule 1 controlled substance. A major breakthrough in understanding the pharmacology of cannabis came with the isolation and characterization of the phytocannabinoids trans-Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). This was followed by the cloning of the cannabinoid CB1 and CB2 receptors in the 1990s and the subsequent discovery of the endocannabinoid system. In addition to the major phytocannabinoids, Δ9-THC and CBD, cannabis produces over 120 other cannabinoids that are referred to as minor and/or rare cannabinoids. These cannabinoids are produced in smaller amounts in the plant and are derived along with Δ9-THC and CBD from the parent cannabinoid cannabigerolic acid (CBGA). While our current knowledge of minor cannabinoid pharmacology is incomplete, studies demonstrate that they act as agonists and antagonists at multiple targets including CB1 and CB2 receptors, transient receptor potential (TRP) channels, peroxisome proliferator-activated receptors (PPARs), serotonin 5-HT1a receptors and others. The resulting activation of multiple cell signaling pathways, combined with their putative synergistic activity, provides a mechanistic basis for their therapeutic actions. Initial clinical reports suggest that these cannabinoids may have potential benefits in the treatment of neuropathic pain, neurodegenerative diseases, epilepsy, cancer and skin disorders. This review focuses on the molecular pharmacology of the minor cannabinoids and highlights some important therapeutic uses of the compounds.

5.
Trop Dis Travel Med Vaccines ; 6(1): 24, 2020 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-33292661

RESUMEN

BACKGROUND: Sex tourism is defined as travel planned specifically for the purpose of sex, generally to a country where prostitution is legal. While much of the literature on sex tourism relates to the commercial sex worker industry, sex tourism also finds expression in non-transactional sexual encounters. This narrative review explores current concepts related to travel and sex, with a focus on trans-national sex tourism. METHODS: The PubMed database was accessed to source relevant literature, using combinations of pertinent search terms. Only articles published in the English language were selected. Reference lists of published articles were also examined for relevant articles. RESULTS: With regard to preferred destinations, South/Central America and the Caribbean were more likely to receive tourists looking for casual sex. Longer duration of travel, travelling alone or with friends, alcohol or drug use, being younger and being single were factors associated with higher levels of casual sex overseas. The majority of literature retrieved on sex workers focused on risk behaviours, sexually transmitted infections (STI), mobility of sex workers and how these factors affected their lives. Sex tourists require better access to effective methods of preventing HIV, such as pre-exposure prophylaxis, and better education on HIV prevention. Drugs and alcohol play a major role as risk factors for and cofactors in casual sexual behaviour while abroad. CONCLUSIONS: Travellers need to be informed of the increased risks of STI before travel. They should be aware of the local prevalence of STIs and the risks associated with their sexual practices when they travel, including engaging with commercial sex workers, having unprotected sexual intercourse and becoming victims of sexual violence.

7.
J Microbiol Methods ; 164: 105681, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31381981

RESUMEN

Currently, in the state of Colorado and all other states within the United States of America with legalized marijuana programs, testing is required for bacteria, yeast, and mold on marijuana products. The Code of Colorado Regulations, 1 CCR 212-1, considers a passing result when a 1 g sample contains <104 colony forming units (CFU) for the total yeast and mold count (TYMC). These measurements are usually obtained by manually counting colonies on petri-dishes or 3 M™ Petrifilms™, which is a time consuming and user subjective process. Therefore, an automated counting method utilizing ImageJ has been developed for CFU analysis of TYMC on Petrifilms. The performance of this colony counting method was demonstrated by comparing manual and automated counts from marijuana flower samples containing spikes of Candida albicans as well as samples that tested positive for the presence of yeast and mold. Fifteen images of Petrifilms showing various concentrations of colonies were studied by fifteen users at two institutions using both the automated and manual counting methods. All counts from the automated ImageJ procedure were within 12% of those obtained manually. In twelve out of fifteen Petrifilms, the average count of the automated method was statistically similar to the manual counts. The statistical differences of the other three samples were observed to be random and caused by user errors. The automated counting method could be used to quickly count numbers that are as high as 400 CFUs, reducing time of analysis with improved documentation because the images and the electronic colony counts can be saved on a computer or cloud for long term storage and data access.


Asunto(s)
Cannabis/microbiología , Recuento de Colonia Microbiana/métodos , Flores/microbiología , Procesamiento de Imagen Asistido por Computador/métodos , Levaduras/crecimiento & desarrollo , Candida albicans/crecimiento & desarrollo , Recuento de Colonia Microbiana/instrumentación , Procesamiento de Imagen Asistido por Computador/instrumentación , Técnicas Microbiológicas/métodos , Células Madre
8.
J Vis Exp ; (143)2019 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-30735194

RESUMEN

A higher-throughput microfluidic in vitro bioreactor coupled with fluorescence microscopy has been used to study bacterial biofilm growth and morphology, including Pseudomonas aeruginosa (P. aeruginosa). Here, we will describe how the system can be used to study the growth kinetics and the morphological properties such as the surface roughness and textural entropy of P. aeruginosa strain PA01 that expresses an enhanced green fluorescent protein (PA01-EGFP). A detailed protocol will describe how to grow and seed PA01-EGFP cultures, how to set up the microscope and autorun, and conduct the image analysis to determine growth rate and morphological properties using a variety of shear forces that are controlled by the microfluidic device. This article will provide a detailed description of a technique to improve the study of PA01-EGFP biofilms which eventually can be applied towards other strains of bacteria, fungi, or algae biofilms using the microfluidic platform.


Asunto(s)
Proteínas Fluorescentes Verdes/metabolismo , Microfluídica/métodos , Pseudomonas aeruginosa/fisiología , Estrés Mecánico , Automatización , Biopelículas/crecimiento & desarrollo , Reactores Biológicos , Entropía , Procesamiento de Imagen Asistido por Computador , Microscopía Fluorescente , Pseudomonas aeruginosa/crecimiento & desarrollo , Programas Informáticos
9.
J Chem Educ ; 96(11): 2441-2449, 2019 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-33911314

RESUMEN

The "International Research Experience for Students (IRES)" at Doane University (DU) located in Crete, Nebraska, exposed undergraduate science, technology, engineering, and mathematics (STEM) students to international research at the Karlsruhe Institute of Technology (KIT) in Germany. The international collaboration team included three undergraduate researchers per year from DU, one faculty member and one postdoctoral fellow from DU, two faculty mentors at KIT, and several graduate, post-doctoral, and technical staff at KIT. Prior to departure to Germany, the students received extensive research training, as well as culture and language preparation from the mentors at DU. While in Germany, the students received an in-depth orientation to Karlsruhe, Germany, Europe, the research setting at KIT, and the international collaborators. The eight week summer projects over three years involved nanolithography, nano- to microsized array fabrication, organic synthesis using click chemistry, and surface modifications for sensing and other biomedical research applications. When the students returned from Germany, they continued to conduct research at DU and train other undergraduate students using the expertise acquired from KIT. The DU research students, including the IRES scholars, learned oral and written communication skills. They presented their KIT and DU research results at weekly seminars and at local and national meetings. An external assessment firm evaluated the program, the students, and mentors on a yearly basis before and after the summer research. This enabled all participants to continuously improve the learning objectives and the program execution including three program adjustments implemented in year 2 or 3. The survey data shows that the IRES program provided an enriching experience for the students in research and international culture and established a successful base of collaboration for mentors.

10.
Sensors (Basel) ; 18(12)2018 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-30563195

RESUMEN

Chemical warfare agents pose significant threats in the 21st century, especially for armed forces. A colorimetric detection array was developed to identify warfare mimics, including mustard gas and nerve agents. In total, 188 sensors were screened to determine the best sensor performance, in order to identify warfare mimics 2-chloro ethyl ethylsulfide, 2-2'-thiodiethanol, trifluoroacetic acid, methylphosphonic acid, dimethylphosphite, diethylcyanophosphonate, and diethyl (methylthiomethyl)phosphonate. The highest loadings in the principle component analysis (PCA) plots were used to identify the sensors that were most effective in analyzing the RGB data to classify the warfare mimics. The dataset was reduced to only twelve sensors, and PCA results gave comparable results as the large data did, demonstrating that only twelve sensors are needed to classify the warfare mimics.


Asunto(s)
Sustancias para la Guerra Química/análisis , Colorimetría/métodos , Sustancias para la Guerra Química/química , Color , Análisis de Componente Principal
11.
Anal Chem ; 90(16): 9990-9996, 2018 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-30027740

RESUMEN

Solid supported colorimetric sensing arrays have the advantage of portability and ease of use when deployed in the field, such as crime scenes, disaster zones, or in war zones, but many sensor arrays require complex fabrication methods. Here, we report a practical method for the fabrication of 4 × 4 colorimetric sensor arrays, which are printed on nylon membranes, using a commercially available inkjet printer. In order to test the efficacy of the printed arrays, they were exposed to 43 analytes at concentrations ranging from 0.001 to 3.0 M for a total of 559 samples of inorganic and organic acids or bases including hydrochloric, acetic, phthalic, malonic, picric, and trifluoroacetic acid, ammonium hydroxide, sodium hydroxide, lysine, and water as the control. Colorimetric data from the imaged arrays was analyzed with linear discriminant analysis and k-nearest neighbors to determine the analyte and concentration with ∼88-90% accuracy. Overall, the arrays have impressive analytical power to identify a variety of analytes at different concentrations while being simple to fabricate.


Asunto(s)
Ácidos Carboxílicos/análisis , Colorimetría/métodos , Ácido Clorhídrico/análisis , Hidróxidos/análisis , Lisina/análisis , Colorimetría/instrumentación , Análisis Discriminante , Impresión
12.
J Chemom ; 32(2)2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29795964

RESUMEN

With the increasing availability of digital imaging devices, colorimetric sensor arrays are rapidly becoming a simple, yet effective tool for the identification and quantification of various analytes. Colorimetric arrays utilize colorimetric data from many colorimetric sensors, with the multidimensional nature of the resulting data necessitating the use of chemometric analysis. Herein, an 8 sensor colorimetric array was used to analyze select acid and basic samples (0.5 - 10 M) to determine which chemometric methods are best suited for classification quantification of analytes within clusters. PCA, HCA, and LDA were used to visualize the data set. All three methods showed well-separated clusters for each of the acid or base analytes and moderate separation between analyte concentrations, indicating that the sensor array can be used to identify and quantify samples. Furthermore, PCA could be used to determine which sensors showed the most effective analyte identification. LDA, KNN, and HQI were used for identification of analyte and concentration. HQI and KNN could be used to correctly identify the analytes in all cases, while LDA correctly identified 95 of 96 analytes correctly. Additional studies demonstrated that controlling for solvent and image effects was unnecessary for all chemometric methods utilized in this study.

13.
J Feline Med Surg ; 20(2): 189-199, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29366400

RESUMEN

Case series summary Feline tuberculosis is an increasingly recognised potential zoonosis of cats. Treatment is challenging and prognosis can vary greatly between cases. Pulmonary infection requires extended courses of antibiotics, but methodologies for sensitively monitoring response to treatment are currently lacking. In this case series, we retrospectively examined the serial computed tomography (CT) findings in nine cats that had been diagnosed with tuberculosis. Changes in pathology (where applicable to tuberculosis) were correlated with the clinical presentation of each of the cats, the treatment protocol, and previous and contemporary diagnostic investigations. This study found that changes in CT findings during the medium- to long-term management of feline tuberculosis were highly variable between cats. The majority of cats had reduced pathology at re-examination during anti-tuberculous therapy, but pathology only resolved in a minority of cases. In some cases recurrence of pathology detected by CT imaging preceded clinical deterioration, allowing for rapid therapeutic intervention. Relevance and novel information When considered in combination with clinical findings, CT studies can aid in decision making regarding tapering of antibiotic protocols, or reintroduction of therapy in cases of recurrence or reinfection. This series also highlights that, in some cases, persistent abnormalities can be detected by CT, so complete resolution of CT pathology should not always be a goal in the management of feline tuberculosis.


Asunto(s)
Enfermedades de los Gatos/diagnóstico por imagen , Tomografía Computarizada por Rayos X/veterinaria , Tuberculosis/veterinaria , Animales , Gatos , Femenino , Estudios de Seguimiento , Masculino , Estudios Retrospectivos , Tuberculosis/diagnóstico por imagen
14.
Chemosensors (Basel) ; 6(2)2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31741893

RESUMEN

A variety of direct and indirect methods have been used to quantify planktonic and biofilm bacterial cells. Direct counting methods to determine the total number of cells include plate counts, microscopic cell counts, Coulter cell counting, flow cytometry, and fluorescence microscopy. However, indirect methods are often used to supplement direct cell counting, as they are often more convenient, less time-consuming, and require less material, while providing a number that can be related to the direct cell count. Herein, an indirect method is presented that uses fluorescence emission intensity as a proxy marker for studying bacterial accumulation. A clinical strain of Pseudomonas aeruginosa was genetically modified to express a green fluorescent protein (PA14/EGFP). The fluorescence intensity of EGFP in live cells was used as an indirect measure of live cell density, and was compared with the traditional cell counting methods of optical density (OD600) and plate counting (colony-forming units (CFUs)). While both OD600 and CFUs are well-established methods, the use of fluorescence spectroscopy to quantify bacteria is less common. This study demonstrates that EGFP intensity is a convenient reporter for bacterial quantification. In addition, we demonstrate the potential for fluorescence spectroscopy to be used to measure the quantity of PA14/EGFP biofilms, which have important human health implications due to their antimicrobial resistance. Therefore, fluorescence spectroscopy could serve as an alternative or complementary quick assay to quantify bacteria in planktonic cultures and biofilms.

15.
Int J Chem ; 10(2): 36-55, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31745401

RESUMEN

Colorimetric sensor arrays incorporating red, green, and blue (RGB) image analysis use value changes from multiple sensors for the identification and quantification of various analytes. RGB data can be easily obtained using image analysis software such as ImageJ. Subsequent chemometric analysis is becoming a key component of colorimetric array RGB data analysis, though literature contains mainly principal component analysis (PCA) and hierarchical cluster analysis (HCA). Seeking to expand the chemometric methods toolkit for array analysis, we explored the performance of nine chemometric methods were compared for the task of classifying 631 solutions (0.1 to 3 M) of acetic acid, malonic acid, lysine, and ammonia using an eight sensor colorimetric array. PCA and LDA (linear discriminant analysis) were effective for visualizing the dataset. For classification, linear discriminant analysis (LDA), (k nearest neighbors) KNN, (soft independent modelling by class analogy) SIMCA, recursive partitioning and regression trees (RPART), and hit quality index (HQI) were very effective with each method classifying compounds with over 90% correct assignments. Support vector machines (SVM) and partial least squares - discriminant analysis (PLS-DA) struggled with ~85 and 39% correct assignments, respectively. Additional mathematical treatments of the data set, such as incrementally increasing the exponents, did not improve the performance of LDA and KNN. The literature precedence indicates that the most common methods for analyzing colorimetric arrays are PCA, LDA, HCA, and KNN. To our knowledge, this is the first report of comparing and contrasting several more diverse chemometric methods to analyze the same colorimetric array data.

16.
Int J Nanotechnol Eng Med ; 3(3): 35-42, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31897448

RESUMEN

Slippery, porous polymeric antimicrobial surfaces for biofilm attachment inhibition of the clinical strain Pseudomonas aeruginosa (PA14) have been prepared. Porous BMA-EDMA, characterized for its hydrophobic properties, was infused with a slippery liquid creating a hydrophobic liquid interface and characterized by water contact angle and SEM. A low shear force bioreactor was used to prepare biofilms on these antimicrobial surfaces. Biofilm attachment was studied using fluorescence microscopy coupled with image analysis in ImageJ. While the literature presents that these slippery polymers work well as antimicrobial surfaces for several strains of Pseudomonas aeruginosa, it has been found to be strain dependent. This report demonstrates that slippery surfaces do not work well for the strain PA14, and biofilm covered >3.5 times more area as compared to the control glass surfaces.

17.
Front Plant Sci ; 8: 1513, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28912796

RESUMEN

Plant root exudates are important mediators in the interactions that occur between plants and microorganisms in the soil, yet much remains to be learned about spatial and temporal variation in their production. This work outlines a method utilizing a novel colorimetric paper to detect spatial and temporal changes in the production of nitrogen-containing compounds on the root surface. While existing methods have made it possible to conduct detailed analysis of root exudate composition, relatively less is known about where in the root system exudates are produced and how this localization changes as the root grows. Furthermore, there is much to learn about how exudate localization and composition varies in response to stress. Root exudates are chemically diverse secretions composed of organic acids, amino acids, proteins, sugars, and other metabolites. The sensor utilized for the method, ninhydrin, is a colorless substance in solution that reacts with free amino groups to form a purple dye. A detection paper was developed by formulating ninhydrin into a print solution that was uniformly deposited onto paper with a commercial ink jet printer. This "ninhydrin paper" was used to analyze the chemical makeup of root surfaces from maize seedlings grown vertically on germination paper. Through contact between the ninhydrin paper and seedling root surfaces, combined with images of both the seedlings and dried ninhydrin papers captured using a standard flatbed scanner, nitrogen-containing substances on the root surface can be localized and concentration of signal estimated for over 2 weeks of development. The method was found to be non-inhibiting to plant growth over the analysis period although damage to root hairs was observed. The method is sensitive in the detection of free amines at concentrations as little as 140 µM. Furthermore, ninhydrin paper is stable, showing consistent color changes up to 2 weeks after printing. This relatively simple, low-cost method could contribute to a better understanding of root exudates and mechanisms used by plants to interact with the complex soil environment during growth and development.

18.
ACS Appl Mater Interfaces ; 9(13): 12109-12117, 2017 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-28296390

RESUMEN

Protein-repellent reactive surfaces that promote localized specific binding are highly desirable for applications in the biomedical field. Nonspecific adhesion will compromise the function of bioactive surfaces, leading to ambiguous results of binding assays and negating the binding specificity of patterned cell-adhesive motives. Localized specific binding is often achieved by attaching a linker to the surface, and the other side of the linker is used to bind specifically to a desired functional agent, as e.g. proteins, antibodies, and fluorophores, depending on the function required by the application. We present a protein-repellent polymer brush enabling highly specific covalent surface immobilization of biorecognition elements by strain-promoted alkyne-azide cycloaddition click chemistry for selective protein adhesion. The protein-repellent polymer brush is functionalized by highly localized molecular binding sites in the low micrometer range using polymer pen lithography (PPL). Because of the massive parallelization of writing pens, the tunable PPL printed patterns can span over square centimeter areas. The selective binding of the protein streptavidin to these surface sites is demonstrated while the remaining polymer brush surface is resisting nonspecific adsorption without any prior blocking by bovine serum albumin (BSA). In contrast to the widely used BSA blocking, the reactive polymer brushes are able to significantly reduce nonspecific protein adsorption, which is the cause of biofouling. This was achieved for solutions of single proteins as well as complex biological fluids. The remarkable fouling resistance of the polymer brushes has the potential to improve the multiplexing capabilities of protein probes and therefore impact biomedical research and applications.

19.
Artículo en Inglés | MEDLINE | ID: mdl-30147991

RESUMEN

Bacterial biofilms pose a significant health risk when they grow on devices placed or implanted in the human body. There is a need to develop new materials that can be used as surface coatings on such devices to inhibit biofilm growth. We report on measurements of the biofilm growth rate on a new polymeric material, slippery BMA-EDMA, which can be used as a surface coating for medical devices. Growth rate measurements are also reported for polycarbonate and glass surfaces, for comparison. Measurements are made in a medium shear stress fluid environment. The physical properties of the surfaces are characterized using contact angle, surface roughness, surface skewness and surface kurtosis. Growth rate on the slippery BMA-EDMA is found to be the smallest of the three surfaces. Growth rate is weakly correlated with surface hydrophobicity and surface roughness, while it is strongly correlated with surface skewness and kurtosis.

20.
Res Rev J Eng Technol ; 6(4)2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30214915

RESUMEN

Biofilms are microbial communities attached to a surface and embedded in an extracellular polymeric substance which provides for the protection, stability and nutrients of the various bacterial species indwelling. These communities can build up in a variety of different environments from industrial equipment to medical devices resulting in damage, loss of productivity and disease. They also have great potential for economic and societal benefits as bioremediation agents and renewable energy sources. The great potential benefits and threats of biofilms has encouraged researchers across disciplines to study biofilm characteristics and antibiofilm strategies resulting in chemists, physicists, material scientists, and engineers, to develop beneficial biofilm applications and prevention methods. The ultimate outcome is a wealth of knowledge and innovative technology. However, without extensive formal training in microbes and biofilm research, these scientists find a daunting array of established techniques for growing, quantifying and characterizing biofilms while trying to design experiments and develop innovative laboratory protocols. This mini-review focuses on enriching interdisciplinary efforts and understanding by overviewing a variety of quantitative and qualitative biofilm characterization methods to assist the novice researcher in assay selection. This review consists of four parts. Part 1 is a brief overview of biofilms and the unique properties that demand a highly interdisciplinary approach. Part 2 describes the classical quantification techniques including colony forming unit (CFU) counting and crystal violet staining, but also introduces some modern methods including ATP bioluminescence and quartz crystal microbalance. Part 3 focuses on the characterization of biofilm morphology and chemistry including scanning electron microscopy and spectroscopic methods. Finally, Part 4 illustrates the use of software, including ImageJ and predictive modeling platforms, for biofilm analysis. Each section highlights the most common methods, including literature references, to help novice biofilm researchers make choices which commensurate with their study goals, budget and available equipment.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...