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Kumar D, Oberoi HS, Singh H, Shrivastav TG, Bhukya PL, Kumari M, Koner BC, Sonkar SC. Development and optimization of an in-house heterologous ELISA for detection of prednisolone drug in enzyme conjugates using spacers. Front Immunol 2023; 14:1200328. [PMID: 37675116 PMCID: PMC10477981 DOI: 10.3389/fimmu.2023.1200328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/20/2023] [Indexed: 09/08/2023] Open
Abstract
The introduction of spacers in coating steroid protein complexes and/or enzyme conjugates or immunogens is known to exert an influence on the sensitivity of steroid enzyme immunoassays. We investigated the impact of different homobifunctional spacers, ranging in atomic length from 3 to 10, on the sensitivity and specificity of prednisolone (PSL) enzyme immunoassays. In this study, four homo-bifunctional spacers, namely, carbohydrazide (CH), adipic acid dihydrazide (ADH), ethylene diamine (EDA), and urea (U), were incorporated between PSL and horseradish peroxidase (HRP) for preparing the enzyme conjugate with an aim to improve the sensitivity of the assay without compromising assay specificity. The assays were developed using these enzymes conjugated with antibodies raised against the PSL-21-HS-BSA immunogen. The sensitivity of the PSL assays after insertion of a bridge in the enzyme conjugate was 1.22 ng/mL, 0.59 ng/mL, 0.48 ng/mL, and 0.018 ng/mL with ADH, CH, EDA, and urea as a spacer, respectively. Among the four combinations, the PSL-21-HS-BSA-antibody with PSL-21-HS-U-HRP-enzyme conjugate gave better sensitivity and less cross-reaction. The percent recovery of PSL from the exogenously spiked human serum pools was in the range of 88.32%-102.50%. The intra and inter-assay CV% was< 8.46%. The PSL concentration was estimated in the serum samples of patients on PSL treatment. The serum PSL values obtained by this method correlated well with the commercially available kit (r2 = 0.98). The present study suggests that the nature of the spacer is related to assay sensitivity and not the spacer length.
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Affiliation(s)
- Dinesh Kumar
- Department of Reproductive Biomedicine, National Institute of Health and Family Welfare (NIHFW), New Delhi, India
- Quality Assurance Division, Food Safety and Standards Authority of India (FSSAI), New Delhi, India
| | - Harinder Singh Oberoi
- Quality Assurance Division, Food Safety and Standards Authority of India (FSSAI), New Delhi, India
| | - Harpal Singh
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi (IIT-D), New Delhi, India
- Department of Biomedical Engineering, All India Institute of Medical Sciences Delhi (AIIMS-D), New Delhi, India
| | - Tulsidas G. Shrivastav
- Department of Reproductive Biomedicine, National Institute of Health and Family Welfare (NIHFW), New Delhi, India
| | - Prudhvi Lal Bhukya
- Rodent Experimentation Facility, Indian Council of Medical Research (ICMR)-National Animal Resource Facility for Biomedical Research (Indian Council of Medical Research (ICMR)-NARFBR), Hyderabad, India
| | - Mansi Kumari
- Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - Bidhan Chandra Koner
- Multidisciplinary Research Unit, Maulana Azad Medical College and Associated Hospital, New Delhi, India
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospital, New Delhi, India
| | - Subash Chandra Sonkar
- Multidisciplinary Research Unit, Maulana Azad Medical College and Associated Hospital, New Delhi, India
- Delhi School of Public Health, Institute of Eminence, University of Delhi, Delhi, India
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Janssen DMC, Willems P, Geurts J, Arts CJJ. Antibiotic release from PMMA spacers and PMMA beads measured with ELISA: Assessment of in vitro samples and drain fluid samples of patients. J Orthop Res 2023; 41:1831-1839. [PMID: 36597743 DOI: 10.1002/jor.25510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/30/2022] [Accepted: 12/21/2022] [Indexed: 01/05/2023]
Abstract
For prosthetic joint infections, antibiotic loaded poly methyl methacrylate (PMMA) spacer or beads can be used to release high concentrations of antibiotics locally at the infection site, while minimizing systemic toxicity. The aim of this study is to determine in vitro and in vivo pharmacokinetic release profile of antibiotics from PMMA spacers and PMMA beads. For the in vitro experiment, the PMMA spacers or beads were submerged in phosphate-buffered saline and gentamicin concentrations were determined from collected specimen at several times points, measured with enzyme-linked immunosorbent assays (ELISA). To assess the in vivo antibiotic release profile of different spacers, wound drainage fluid samples were collected after implantation of a spacer over a period of maximum 14 days. After 48 h, the burst gentamicin concentration elution was 9862 ± 1782 ng/ml (mean ± SD) from spacers versus 38,394 ± 7071 ng/ml (mean ± SD) for beads. Over 35 days, spacers had eluted a cumulative mean concentration of 13,812 ± 3548 versus 55,048 ± 12,006 ng/ml for beads (p < 0.001). Clinical samples of patients with a Vancogenx® spacer showed higher gentamicin release than Refobacin™ spacers (p < 0.001). This is the first study that measured the release data of local antibiotics with ELISA. Compare to spacers, the exact release values of gentamicin from PMMA beads are more than 10 times higher and reached a maximum much later than spacers. This makes the use of PMMA beads more preferable to use for treatment of the infection itself.
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Affiliation(s)
- Daniël M C Janssen
- Department of Orthopaedic Surgery, Laboratory for Experimental Orthopaedics, Research School CAPHRI, Maastricht University Medical Centre+, Maastricht, The Netherlands
- Sint-Trudo Hospital, Sint-Truiden, Belgium
| | - Paul Willems
- Department of Orthopaedic Surgery, Laboratory for Experimental Orthopaedics, Research School CAPHRI, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Jan Geurts
- Department of Orthopaedic Surgery, Laboratory for Experimental Orthopaedics, Research School CAPHRI, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Chris J J Arts
- Department of Orthopaedic Surgery, Laboratory for Experimental Orthopaedics, Research School CAPHRI, Maastricht University Medical Centre+, Maastricht, The Netherlands
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Alkompoz AK, Hamed SM, Zaid ASA, Almangour TA, Al-Agamy MH, Aboshanab KM. Correlation of CRISPR/Cas and Antimicrobial Resistance in Klebsiella pneumoniae Clinical Isolates Recovered from Patients in Egypt Compared to Global Strains. Microorganisms 2023; 11:1948. [PMID: 37630508 PMCID: PMC10459600 DOI: 10.3390/microorganisms11081948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
The CRISPR/Cas system has been long known to interfere with the acquisition of foreign genetic elements and was recommended as a tool for fighting antimicrobial resistance. The current study aimed to explore the prevalence of the CRISPR/Cas system in Klebsiella pneumoniae isolates recovered from patients in Egypt in comparison to global strains and correlate the CRISPR/Cas to susceptibility to antimicrobial agents. A total of 181 clinical isolates were PCR-screened for cas and selected antimicrobial resistance genes (ARGs). In parallel, 888 complete genome sequences were retrieved from the NCBI database for in silico analysis. CRISPR/Cas was found in 46 (25.4%) isolates, comprising 18.8% type I-E and 6.6% type I-E*. Multidrug resistance (MDR) and extensive drug resistance (XDR) were found in 73.5% and 25.4% of the isolates, respectively. More than 95% of the CRISPR/Cas-bearing isolates were MDR (65.2%) or XDR (32.6%). No significant difference was found in the susceptibility to the tested antimicrobial agents among the CRISPR/Cas-positive and -negative isolates. The same finding was obtained for the majority of the screened ARGs. Among the published genomes, 23.2% carried CRISPR/Cas, with a higher share of I-E* (12.8%). They were confined to specific sequence types (STs), most commonly ST147, ST23, ST15, and ST14. More plasmids and ARGs were carried by the CRISPR/Cas-negative group than others, but their distribution in the two groups was not significantly different. The prevalence of some ARGs, such as blaKPC, blaTEM, and rmtB, was significantly higher among the genomes of the CRISPR/Cas-negative strains. A weak, nonsignificant positive correlation was found between the number of spacers and the number of resistance plasmids and ARGs. In conclusion, the correlation between CRISPR/Cas and susceptibility to antimicrobial agents or bearing resistance plasmids and ARGs was found to be nonsignificant. Plasmid-targeting spacers might not be naturally captured by CRISPR/Cas. Spacer match analysis is recommended to provide a clearer image of the exact behavior of CRISPR/Cas towards resistance plasmids.
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Affiliation(s)
| | - Samira M. Hamed
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), 6th of October, Giza 12451, Egypt;
| | - Ahmed S. Abu Zaid
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt;
| | - Thamer A. Almangour
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Mohamed H. Al-Agamy
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
- Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University, Cairo 11651, Egypt
| | - Khaled M. Aboshanab
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt;
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Wu J, Zhang H, Gan R, Xia Y, Zhang F, Wang D, Fu J, Barraclough TG. CRISPR dynamics during the interaction between bacteria and phage in the first year of life. Microb Genom 2023; 9:mgen001053. [PMID: 37402176 PMCID: PMC10438810 DOI: 10.1099/mgen.0.001053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/26/2023] [Indexed: 07/06/2023] Open
Abstract
Gut microbiomes in infancy have a profound impact on health in adulthood. CRISPRs play an essential role in the interaction between bacteria and phages. However, the dynamics of CRISPRs in gut microbiomes during early life are poorly understood. In this study, using shotgun metagenomic sequencing data from 82 Swedish infants' gut microbiomes, 1882 candidate CRISPRs were identified, and their dynamics were analysed. We found large-scale turnover of CRISPRs and their spacers during the first year of life. As well as changes in relative abundance of the bacteria containing CRISPR, acquisition, loss and mutation of spacers were observed within the same CRISPR array sampled over time. Accordingly, the inferred interaction network of bacteria and phage was distinct at different times. This research underpins CRISPR dynamics and their potential role in the interaction between bacteria and phage in early life.
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Affiliation(s)
- Jiqiu Wu
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY, UK
- West China Biomedical Big Data Center, West China Hospital/West China School of Medicine, Sichuan University, Chengdu 610041, PR China
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen 9713 AV, Netherlands
| | - Hanyun Zhang
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY, UK
- Division of Molecular Pathology, The Institute of Cancer Research, London SM2 5NG, UK
| | - Rui Gan
- Changping Laboratory, Beijing 102206, PR China
| | - Yan Xia
- 01Life Institute, Shenzhen 518000, PR China
| | - Fan Zhang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, PR China
| | - Daoming Wang
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen 9713 AV, Netherlands
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713AV, Netherlands
| | - Jingyuan Fu
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen 9713 AV, Netherlands
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713AV, Netherlands
| | - Timothy G. Barraclough
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY, UK
- Department of Biology, University of Oxford, 11a Mansfield Rd, Oxford OX1 3SZ, UK
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Wasilewski T, Neubauer D, Wojciechowski M, Szulczyński B, Gębicki J, Kamysz W. Evaluation of Linkers' Influence on Peptide-Based Piezoelectric Biosensors' Sensitivity to Aldehydes in the Gas Phase. Int J Mol Sci 2023; 24:10610. [PMID: 37445789 DOI: 10.3390/ijms241310610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/20/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
Recent findings qualified aldehydes as potential biomarkers for disease diagnosis. One of the possibilities is to use electrochemical biosensors in point-of-care (PoC), but these need further development to overcome some limitations. Currently, the primary goal is to enhance their metrological parameters in terms of sensitivity and selectivity. Previous findings indicate that peptide OBPP4 (KLLFDSLTDLKKKMSEC-NH2) is a promising candidate for further development of aldehyde-sensitive biosensors. To increase the affinity of a receptor layer to long-chain aldehydes, a structure stabilization of the peptide active site via the incorporation of different linkers was studied. Indeed, the incorporation of linkers improved sensitivity to and binding of aldehydes in comparison to that of the original peptide-based biosensor. The tendency to adopt disordered structures was diminished owing to the implementation of suitable linkers. Therefore, to improve the metrological characteristics of peptide-based piezoelectric biosensors, linkers were added at the C-terminus of OBPP4 peptide (KLLFDSLTDLKKKMSE-linker-C-NH2). Those linkers consist of proteinogenic amino acids from group one: glycine, L-proline, L-serine, and non proteinogenic amino acids from group two: β-alanine, 4-aminobutyric acid, and 6-aminohexanoic acid. Linkers were evaluated with in silico studies, followed by experimental verification. All studied linkers enhanced the detection of aldehydes in the gas phase. The highest difference in frequency (60 Hz, nonanal) was observed between original peptide-based biosensors and ones based on peptides modified with the GSGSGS linker. It allowed evaluation of the limit of detection for nonanal at the level of 2 ppm, which is nine times lower than that of the original peptide. The highest sensitivity values were also obtained for the GSGSGS linker: 0.3312, 0.4281, and 0.4676 Hz/ppm for pentanal, octanal, and nonanal, respectively. An order of magnitude increase in sensitivity was observed for the six linkers used. Generally, the linker's rigidity and the number of amino acid residues are much more essential for biosensors' metrological characteristics than the amino acid sequence itself. It was found that the longer the linkers, the better the effect on docking efficiency.
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Affiliation(s)
- Tomasz Wasilewski
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland
| | - Damian Neubauer
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland
| | - Marek Wojciechowski
- Department of Pharmaceutical Technology and Biochemistry, Chemical Faculty, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Bartosz Szulczyński
- Department of Process Engineering and Chemical Technology, Chemical Faculty, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Jacek Gębicki
- Department of Process Engineering and Chemical Technology, Chemical Faculty, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Wojciech Kamysz
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland
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Uzdenova A, Kovalenko A, Prosviryakov E, Urtenov M. Mathematical Modeling of the Influence of the Karman Vortex Street on Mass Transfer in Electromembrane Systems. Membranes (Basel) 2023; 13:membranes13040394. [PMID: 37103821 PMCID: PMC10140957 DOI: 10.3390/membranes13040394] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 05/31/2023]
Abstract
In electromembrane systems, the transfer of ions near ion-exchange membranes causes concentration polarization, which significantly complicates mass transfer. Spacers are used to reduce the effect of concentration polarization and increase mass transfer. In this article, for the first time, a theoretical study is carried out, using a two-dimensional mathematical model, of the effect of spacers on the mass transfer process in the desalination channel formed by anion-exchange and cation-exchange membranes under conditions when they cause a developed Karman vortex street. The main idea is that, when the separation of vortices occurs on both sides in turn from the spacer located in the core of the flow where the concentration is maximum, the developed non-stationary Karman vortex street ensures the flow of the solution from the core of the flow alternately into the depleted diffusion layers near the ion-exchange membranes. This reduces the concentration polarization and, accordingly, increases the transport of salt ions. The mathematical model is a boundary value problem for the coupled system of Nernst-Planck-Poisson and Navier-Stokes equations for the potentiodynamic regime. The comparison of the current-voltage characteristics calculated for the desalination channel with and without a spacer showed a significant increase in the intensity of mass transfer due to the development of the Karman vortex street behind the spacer.
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Affiliation(s)
- Aminat Uzdenova
- Department of Computer Science and Computational Mathematics, Umar Aliev Karachai-Cherkess State University, Karachaevsk 369202, Russia
| | - Anna Kovalenko
- Department of Data Analysis and Artificial Intelligence, Kuban State University, Krasnodar 350040, Russia
| | - Evgeniy Prosviryakov
- Department of Information Technologies and Control Systems, Ural Federal University the first President of Russia B. N. Yeltsin, 19 Mira St., Ekaterinburg 620049, Russia
| | - Makhamet Urtenov
- Department of Applied Mathematics, Kuban State University, Krasnodar 350040, Russia
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Barchi Y, Philippe C, Chaïb A, Oviedo-Hernandez F, Claisse O, Le Marrec C. Phage Encounters Recorded in CRISPR Arrays in the Genus Oenococcus. Viruses 2022; 15:15. [PMID: 36680056 PMCID: PMC9867325 DOI: 10.3390/v15010015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 12/10/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
The Oenococcus genus comprises four recognized species, and members have been found in different types of beverages, including wine, kefir, cider and kombucha. In this work, we implemented two complementary strategies to assess whether oenococcal hosts of different species and habitats were connected through their bacteriophages. First, we investigated the diversity of CRISPR-Cas systems using a genome-mining approach, and CRISPR-endowed strains were identified in three species. A census of the spacers from the four identified CRISPR-Cas loci showed that each spacer space was mostly dominated by species-specific sequences. Yet, we characterized a limited records of potentially recent and also ancient infections between O. kitaharae and O. sicerae and phages of O. oeni, suggesting that some related phages have interacted in diverse ways with their Oenococcus hosts over evolutionary time. Second, phage-host interaction analyses were performed experimentally with a diversified panel of phages and strains. None of the tested phages could infect strains across the species barrier. Yet, some infections occurred between phages and hosts from distinct beverages in the O. oeni species.
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Affiliation(s)
| | | | | | | | | | - Claire Le Marrec
- UMR Oenologie 1366, Univ. Bordeaux, INRAE, Bordeaux INP, Bordeaux Sciences Agro, Institut des Sciences de la Vigne et du Vin, 33882 Villenave d’Ornon, France
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Tony SM, Abdelrahman MA, Abd Elsalam M, Sameer Shafik M, Abdelrahim MEA. Effect of using acoustic flo-tone training device and its smartphone application on enhancing inhalation technique from metered-dose inhaler with spacer in asthmatic children. Exp Lung Res 2022; 48:224-238. [PMID: 35997099 DOI: 10.1080/01902148.2022.2113573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aim of study: This research study aims to compare between two different counseling approaches; traditional verbal counseling vs. advanced counseling (in which we used the acoustic Flo-tone training device and its smartphone application combined with traditional verbal counseling) to determine the most beneficial counseling approach for asthmatic children who use metered-dose inhaler (MDI) with spacers concerning inhalation duration and inhalation technique mistakes. Methods: A total of 100 asthmatic children (8-18) years old were randomized into two groups (a control group, and an advanced group). Each group included 50 subjects. Every subject received 3 counseling meetings, one each month. Asthmatic children in the control group were trained on inhalation technique from MDI + spacer verbally (traditional counseling), while asthmatic children in advanced group were trained on inhalation technique from MDI + spacer verbally and by advanced counseling (whistling Flo-tone + smartphone application). At each visit mistakes in inhalation technique steps were; detected, corrected, and recorded and the inhalation duration was measured for every child in each group. Results: In both study groups, the total mean number of inhalation technique mistakes decreased significantly (p < 0.05) from visit 2, also the total mean inhalation durations in seconds showed a significant increase (p < 0.05) from visit 2. A significant (p < 0.05) reduction in the total mean number of mistakes and a significant (p < 0.05) increase in total mean inhalation durations were observed from visit 2 in advanced group compared to control group. Conclusion: Combination between traditional verbal and advanced counseling methods resulted in significant (P < 0.05) improvements in the number of inhalation technique mistakes and inhalation durations from MDI with spacer in children compared to using traditional verbal counseling alone.
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Affiliation(s)
- Sara M Tony
- Beni-Suef Specialized Hospital, Beni-Suef, Egypt
| | - Mona A Abdelrahman
- Clinical Pharmacy Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | | | | | - Mohamed E A Abdelrahim
- Clinical Pharmacy Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
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Kamruzzaman M, Yan A, Castro-Escarpulli G. Editorial: CRISPR-Cas Systems in Bacteria and Archaea. Front Microbiol 2022; 13:887778. [PMID: 35422794 PMCID: PMC9002306 DOI: 10.3389/fmicb.2022.887778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/11/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Muhammad Kamruzzaman
- Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - Aixin Yan
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Graciela Castro-Escarpulli
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional de México (IPN), Mexico City, Mexico
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Chitra MA, Varughese HS. Analysis of CRISPR-Cas system and antimicrobial resistance in Staphylococcus coagulans isolates. Lett Appl Microbiol 2022; 75:126-134. [PMID: 35366350 DOI: 10.1111/lam.13713] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/05/2022] [Accepted: 03/30/2022] [Indexed: 12/01/2022]
Abstract
CRISPR-Cas system contributes adaptive immunity to protect the bacterial and archaeal genome against invading mobile genetic elements. In this study, an attempt was made to characterize the CRISPR-Cas system in S. coagulans, the second most prevalent coagulase positive staphylococci causing skin infections in dogs. Out of 45 S. coagulans isolates, 42/45 (93.33%) strains contained CRISPR-Cas system and 45 confirmed CRISPR system was identified in 42 S. coagulans isolates. The length of CRISPR loci ranged from 167 bp to 2477 bp, and the number of spacers in each CRISPR was varied from two spacers to as high as 37 numbers. Direct repeat (DR) sequences were between 30 and 37, but most (35/45) of the direct repeats contained 36 sequences. The predominant S. coagulans strains 29/45 did not possess any antimicrobial resistant genes (ARG); 26/29 strains contained Type IIC CRISPR-Cas system. Three isolates from Antarctica seals neither contain CRISPR-Cas system nor ARG. Only 15/45 S. coagulans strains (33.33%) harboured at least one ARG and 13/15 of them were having mecA gene. All the methicillin susceptible S. coagulans isolates contained Type IIC CRISPR-Cas system. In contrast, many (10/13) S. coagulans isolates which were methicillin resistant had Type IIIA CRISPR-Cas system, and this Type IIIA CRISPR-Cas system was present within the SCCmec mobile genetic element. Hence, this study suggests that Type II CRISPR-Cas in S. coagulans isolates might have played a possible role in preventing acquisition of plasmid/ phage invasion and Type IIIA CRISPR-Cas system may have an insignificant role in the prevention of horizontal gene transfer of antimicrobial resistance genes in S. coagulans species.
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Affiliation(s)
- M Ananda Chitra
- Department of Veterinary Microbiology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, 600007
| | - Hridya Susan Varughese
- Department of Veterinary Microbiology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, 600007
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Devibala P, Balambiga B, Mohamed Imran P, Bhuvanesh NSP, Nagarajan S. Butterfly-Like Triarylamines with High Hole Mobility and On/Off Ratio in Bottom-Gated OFETs. Chemistry 2021; 27:15375-15381. [PMID: 34536306 DOI: 10.1002/chem.202102568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Indexed: 11/05/2022]
Abstract
Highly π-extended butterfly-shaped triarylamine dyads with aryleneethynylene spacer were constructed using an efficient synthetic route. These aryleneethynylene-bridged dyads are highly fluorescent and exhibited high HOMO levels, and low bandgaps, which are suitable for high-performance p-type OFETs. The field-effect transistors were fabricated through a solution-processable method and exhibited promising p-type performance with field-effect mobility up to 4.3 cm2 /Vs and high Ion/off of 108 under ambient conditions.
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Affiliation(s)
- Panneerselvam Devibala
- Organic Electronics Division, Department of Chemistry Central University of Tamil Nadu, Thiruvarur, 610005, India
| | - Balu Balambiga
- Organic Electronics Division, Department of Chemistry Central University of Tamil Nadu, Thiruvarur, 610005, India
| | | | | | - Samuthira Nagarajan
- Organic Electronics Division, Department of Chemistry Central University of Tamil Nadu, Thiruvarur, 610005, India
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12
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Suter TAM, Clancy AJ, Rubio Carrero N, Heitzmann M, Guetaz L, Shearing PR, Mattevi C, Gebel G, Howard CA, Shaffer MSP, McMillan PF, Brett DJL. Scalable Sacrificial Templating to Increase Porosity and Platinum Utilisation in Graphene-Based Polymer Electrolyte Fuel Cell Electrodes. Nanomaterials (Basel) 2021; 11:2530. [PMID: 34684971 DOI: 10.3390/nano11102530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 11/17/2022]
Abstract
Polymer electrolyte fuel cells hold great promise for a range of applications but require advances in durability for widespread commercial uptake. Corrosion of the carbon support is one of the main degradation pathways; hence, corrosion-resilient graphene has been widely suggested as an alternative to traditional carbon black. However, the performance of bulk graphene-based electrodes is typically lower than that of commercial carbon black due to their stacking effects. This article reports a simple, scalable and non-destructive method through which the pore structure and platinum utilisation of graphene-based membrane electrode assemblies can be significantly improved. Urea is incorporated into the catalyst ink before deposition, and is then simply removed from the catalyst layer after spraying by submerging the electrode in water. This additive hinders graphene restacking and increases porosity, resulting in a significant increase in Pt utilisation and current density. This technique does not require harsh template etching and it represents a pathway to significantly improve graphene-based electrodes by introducing hierarchical porosity using scalable liquid processes.
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13
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Volerman A, Balachandran U, Siros M, Akel M, Press VG. Mask Use with Spacers/Valved Holding Chambers and Metered Dose Inhalers among Children with Asthma. Ann Am Thorac Soc 2021; 18:17-22. [PMID: 33052700 DOI: 10.1513/AnnalsATS.202005-522CME] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inhaler misuse is highly prevalent and associated with high morbidity and costs. For metered dose inhalers, proper use can be supported with devices such as spacers/valved holding chambers (VHCs) and masks to effectively deliver inhaled medication to the lungs. However, guidelines are vague about which children with asthma should use spacers/VHCs with masks to deliver medication from metered dose inhalers as well as when they should transition to spacers/VHCs with mouthpieces. In this paper, we provide a focused review of the evidence for mask use, highlighting unclear and conflicting information in guidelines and studies. We synthesize the differences in recommendations and practice. Based on these findings, we call for future research to determine the appropriate age and necessary skills for transitioning children from using metered dose inhalers with spacers/VHCs and masks to using spacers/VHCs and mouthpieces. Guidelines about mask use should be standardized to help ensure optimal medical delivery for patients, provide consistent inhaler prescriptions and education across settings, and support team-based care to help lower pediatric asthma morbidity and costs.
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14
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Stamereilers C, Wong S, Tsourkas PK. Characterization of CRISPR Spacer and Protospacer Sequences in Paenibacillus larvae and Its Bacteriophages. Viruses 2021; 13:459. [PMID: 33799666 DOI: 10.3390/v13030459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/02/2021] [Accepted: 03/09/2021] [Indexed: 12/01/2022] Open
Abstract
The bacterium Paenibacillus larvae is the causative agent of American foulbrood, the most devastating bacterial disease of honeybees. Because P. larvae is antibiotic resistant, phages that infect it are currently used as alternative treatments. However, the acquisition by P. larvae of CRISPR spacer sequences from the phages could be an obstacle to treatment efforts. We searched nine complete genomes of P. larvae strains and identified 714 CRISPR spacer sequences, of which 384 are unique. Of the four epidemiologically important P. larvae strains, three of these have fewer than 20 spacers, while one strain has over 150 spacers. Of the 384 unique spacers, 18 are found as protospacers in the genomes of 49 currently sequenced P. larvae phages. One P. larvae strain does not have any protospacers found in phages, while another has eight. Protospacer distribution in the phages is uneven, with two phages having up to four protospacers, while a third of phages have none. Some phages lack protospacers found in closely related phages due to point mutations, indicating a possible escape mechanism. This study serve a point of reference for future studies on the CRISPR-Cas system in P. larvae as well as for comparative studies of other phage–host systems.
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15
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Abstract
CRISPR-Cas is one of the mechanisms used by bacteria to defend against viral predation. Increasing our knowledge of the biology and diversity of CRISPR-Cas systems will also improve our understanding of virus-bacterium interactions. As CRISPR-Cas systems acquiring novel immunities under laboratory conditions are rare, Streptococcus mutans strain P42S provides an alternative model to study the adaptation step, which is still the least understood step in CRISPR-Cas biology. Furthermore, the availability of a natural Cas9 protein recognizing an AT-rich PAM opens up new avenues for genome editing purposes. Streptococcus mutans and its virulent phages are important members of the human oral microbiota. S. mutans is also the primary causal agent of dental caries. To survive in this ecological niche, S. mutans must encode phage defense mechanisms, which include CRISPR-Cas systems. Here, we describe the CRISPR-Cas type II-A system of S. mutans strain P42S, which was found to display natural adaptation and interference activity in response to phage infection and plasmid transformation. Newly acquired spacers were integrated both at the 5′ end of the CRISPR locus and ectopically. In comparisons of the cas genes of P42S to those of other strains of S. mutans, cas1, cas2, and csn2 appear to be highly conserved within the species. However, more diversity was observed with cas9. While the nuclease domains of S. mutans Cas9 (SmCas9) are conserved, the C terminus of the protein, including the protospacer adjacent motif (PAM) recognition domain, is less conserved. In support of these findings, we experimentally demonstrated that the PAMs associated with SmCas9 of strain P42S are NAA and NGAA. These PAMs are different from those previously reported for the CRISPR-Cas system of the model strain S. mutans UA159. This study illustrates the diversity of CRISPR-Cas type II-A systems that can be found within the same bacterial species. IMPORTANCE CRISPR-Cas is one of the mechanisms used by bacteria to defend against viral predation. Increasing our knowledge of the biology and diversity of CRISPR-Cas systems will also improve our understanding of virus-bacterium interactions. As CRISPR-Cas systems acquiring novel immunities under laboratory conditions are rare, Streptococcus mutans strain P42S provides an alternative model to study the adaptation step, which is still the least understood step in CRISPR-Cas biology. Furthermore, the availability of a natural Cas9 protein recognizing an AT-rich PAM opens up new avenues for genome editing purposes.
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16
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Shiriaeva A, Fedorov I, Vyhovskyi D, Severinov K. Detection of CRISPR adaptation. Biochem Soc Trans 2020; 48:257-69. [PMID: 32010936 DOI: 10.1042/BST20190662] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/26/2019] [Accepted: 01/03/2020] [Indexed: 12/12/2022]
Abstract
Prokaryotic adaptive immunity is built when short DNA fragments called spacers are acquired into CRISPR (clustered regularly interspaced short palindromic repeats) arrays. CRISPR adaptation is a multistep process which comprises selection, generation, and incorporation of prespacers into arrays. Once adapted, spacers provide immunity through the recognition of complementary nucleic acid sequences, channeling them for destruction. To prevent deleterious autoimmunity, CRISPR adaptation must therefore be a highly regulated and infrequent process, at least in the absence of genetic invaders. Over the years, ingenious methods to study CRISPR adaptation have been developed. In this paper, we discuss and compare methods that detect CRISPR adaptation and its intermediates in vivo and propose suppressing PCR as a simple modification of a popular assay to monitor spacer acquisition with increased sensitivity.
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Divya VV, Sayyed FB, Suresh CH. Substituent Effect Transmission Power of Alkyl, Alkenyl, Alkynyl, Phenyl, Thiophenyl, and Polyacene Spacers. Chemphyschem 2019; 20:1752-1758. [PMID: 30973660 DOI: 10.1002/cphc.201900206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Indexed: 11/08/2022]
Abstract
The transmission of substituent effect through a variety of spacers, that is to say, alkyl, alkenyl, alkynyl, phenyl, thiophenyl, and polyacene has been studied by modeling Y-G-X type molecular systems (Y: reaction center; G: spacer moiety; X: substituent) using B3LYP/6-31G(d,p) density functional theory calculations. The reaction center is always kept as a C=C double bond and the molecular electrostatic potential (MESP) minimum (Vmin ) observed for this bond showed subtle variation with respect to the changes in the spacer unit and the nature of substituent. Strong linear correlations are observed between Hammett substituent constants (σI and σp ) and Vmin , which recommend the aptness of Vmin as an electronic descriptor to quantify the substituent effect. Since Vmin offers an alternative measure of substituent effect, the correlation between Vmin and σp has been used for assessing the transmission of substituent effect through a variety of spacer moieties. The highest transmission coefficient (γ) is always observed for smaller spacer length. Among all the spacers, alkenyl showed the highest and alkyl showed the lowest transmission power. The study recommends the use of short chains of C=C double, C≡C triple or a combination of both as spacers for the effective transmission of substituent effect to the reaction center.
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Affiliation(s)
- Velayudhan V Divya
- Chemical Sciences and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology Thiruvananthapuram, Kerala, 695 019, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India
| | - Fareed Bhasha Sayyed
- Chemical Sciences and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology Thiruvananthapuram, Kerala, 695 019, India
| | - Cherumuttathu H Suresh
- Chemical Sciences and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology Thiruvananthapuram, Kerala, 695 019, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-, 201002, India
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18
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Ramkillawan Y, Prins M, van van Rooyen C, Seedat RY. Assessment of metered-dose inhaler technique: A study at the pulmonology clinic of a tertiary hospital in the Free State, South Africa. Afr J Thorac Crit Care Med 2019; 25. [PMID: 34286241 DOI: 10.7196/AJTCCM.2019.v25i1.232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2019] [Indexed: 11/13/2022] Open
Abstract
Background
Poor pressurised metered-dose inhaler (pMDI) technique remains a challenge in the management of airway diseases.
Objectives
To assess pMDI technique among respiratory outpatients and identify the main indications for pMDI use and factors associated
with improper use.
Methods
This was a prospective, quantitative descriptive study conducted at the adult respiratory clinic of Universitas Academic Hospital
in Bloemfontein, South Africa. A convenience sample of 100 participants was used. Each participant was interviewed and required to
demonstrate the use of a placebo pMDI, either alone or with a large-volume spacer. Inhaler technique was evaluated according to the UK
Inhaler Group standard for inhaler therapy.
Results
Chronic obstructive pulmonary disease and asthma were the most common indications for pMDI use. Of the 100 participants,
97 preferred a pMDI without a spacer (pMDI alone) and three preferred using the inhaler with a spacer. In the pMDI-alone group, 13
participants (13.4%) demonstrated correct technique and 65 (67%) made more than one error.
Conclusion
Poor inhaler technique is common among respiratory outpatients. Every contact with the patient should be an opportunity to
reinforce correct pMDI technique.
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19
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McFarland EG, Rojas J, Smalley J, Borade AU, Joseph J. Complications of antibiotic cement spacers used for shoulder infections. J Shoulder Elbow Surg 2018; 27:1996-2005. [PMID: 29778591 DOI: 10.1016/j.jse.2018.03.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/16/2018] [Accepted: 03/25/2018] [Indexed: 02/01/2023]
Abstract
BACKGROUND Our aim was to evaluate complications related to commercially available antibiotic cement spacers used in the treatment of shoulder infections. METHODS We performed a retrospective review of commercially available antibiotic spacers implanted in 53 patients (60 spacers) between April 2009 and October 2017 as part of a 2-stage treatment plan for infection at the site of a shoulder arthroplasty (n = 39), other (non-arthroplasty) shoulder surgery (n = 8), or primary shoulder infection without previous surgery (n = 6). All patients were followed up from spacer placement to second-stage revision to shoulder arthroplasty. Ten patients retained the spacers and were followed up for a minimum of 1 year. RESULTS No complications were associated with implantation of the spacers. Of the 44 patients (50 spacers) who underwent a second-stage revision after a mean interval of 6 months (range, 2-18 months), 14 patients had 18 complications. Fourteen complications occurred between implantation and removal. The most common complication was bone erosion (6 in the glenoid and 2 in the humeral shaft). Other complications were fractures of the spacer (n = 4), spacer rotation (n = 3), and humeral fracture (n = 3). Two complications required reoperation. There were 4 spacer-related complications among the 10 patients who retained the implant (3 erosions of the humeral shaft and 1 humeral shaft fracture); none required reoperation or removal. CONCLUSIONS Complications related to antibiotic spacers are common especially between the first and second stage of revision, and awareness of these complications is important for the treating provider.
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Affiliation(s)
- Edward G McFarland
- Division of Shoulder Surgery, Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD, USA.
| | - Jorge Rojas
- Division of Shoulder Surgery, Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD, USA
| | - Jeremy Smalley
- Division of Shoulder Surgery, Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD, USA
| | - Amrut U Borade
- Division of Shoulder Surgery, Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD, USA
| | - Jacob Joseph
- Division of Shoulder Surgery, Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD, USA
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20
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Liu W, Liu N, Yue Y, Rao J, Cheng F, Su J, Liu Z, Gao Y. Piezoresistive Pressure Sensor Based on Synergistical Innerconnect Polyvinyl Alcohol Nanowires/Wrinkled Graphene Film. Small 2018; 14:e1704149. [PMID: 29527801 DOI: 10.1002/smll.201704149] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/15/2018] [Indexed: 05/19/2023]
Abstract
Piezoresistive sensor is a promising pressure sensor due to its attractive advantages including uncomplicated signal collection, simple manufacture, economical and practical characteristics. Here, a flexible and highly sensitive pressure sensor based on wrinkled graphene film (WGF)/innerconnected polyvinyl alcohol (PVA) nanowires/interdigital electrodes is fabricated. Due to the synergistic effect between WGF and innerconnected PVA nanowires, the as-prepared pressure sensor realizes a high sensitivity of 28.34 kPa-1 . In addition, the device is able to discern lightweight rice about 22.4 mg (≈2.24 Pa) and shows excellent durability and reliability after 6000 repeated loading and unloading cycles. What is more, the device can detect subtle pulse beat and monitor various human movement behaviors in real-time.
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Affiliation(s)
- Weijie Liu
- Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, 430074, China
| | - Nishuang Liu
- Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, 430074, China
| | - Yang Yue
- Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, 430074, China
| | - Jiangyu Rao
- Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, 430074, China
| | - Feng Cheng
- Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, 430074, China
| | - Jun Su
- Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, 430074, China
| | - Zhitian Liu
- School of Material Science and Engineering, Wuhan Institute of Technology, Liufang Road 1, Wuhan, 430205, China
| | - Yihua Gao
- Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, 430074, China
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21
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Anderson G, Johnson N, Mulgirigama A, Aggarwal B. Use of spacers for patients treated with pressurized metered dose inhalers: focus on the VENTOLIN™ Mini Spacer. Expert Opin Drug Deliv 2018; 15:419-430. [PMID: 29415579 DOI: 10.1080/17425247.2018.1437414] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Spacers offer a multitude of benefits by reducing the requirement to coordinate inhalation with actuation and improving inhaler technique in patients using a pressurized metered dose inhaler (pMDI). Spacers improve drug targeting by retaining within the spacer large particles normally deposited in the oropharynx, and by creating a prolonged aerosol cloud of fine particles to give the user increased time to inhale after actuation. This is particularly important in young children and the elderly to effectively deliver medication to the airways. AREAS COVERED By investigating the history and features of spacers, we demonstrate that the advantages of using spacers far outweigh their limitations. We also discuss the optimal characteristics of spacers in terms of shape, volume, presence of valve and static charge, and present a detailed discussion of the VENTOLIN™ Mini Spacer. EXPERT OPINION Generally, the shape and size of spacers makes them inherently inconvenient. Consideration of human factors and modern design may make them more attractive to patients. However, the incentive to use spacers should be their ability to help patients correctly use inhaled medications delivered by pMDIs. Understanding of these principles through education is key to their acceptance by patients.
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Affiliation(s)
- Gregor Anderson
- a GSK, Respiratory Centre of Excellence, Global Manufactory & Supply , Ware, Herts , UK
| | - Neil Johnson
- b Respiratory, Global Classic & Established Products , GSK , Middlesex , UK
| | - Aruni Mulgirigama
- b Respiratory, Global Classic & Established Products , GSK , Middlesex , UK
| | - Bhumika Aggarwal
- c GSK , Respiratory, Global Classic & Established Products , Singapore
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22
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Vilotte F, Antoine M, Bobin M, Latorzeff I, Supiot S, Richaud P, Thomas L, Leduc N, Guérif S, Iriondo-Alberdi J, de Crevoisier R, Sargos P. Post-Prostatectomy Image-Guided Radiotherapy: The Invisible Target Concept. Front Oncol 2017; 7:34. [PMID: 28337425 PMCID: PMC5343009 DOI: 10.3389/fonc.2017.00034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 02/24/2017] [Indexed: 12/17/2022] Open
Abstract
In the era of intensity-modulated radiation therapy, image-guided radiotherapy (IGRT) appears crucial to control dose delivery and to promote dose escalation while allowing healthy tissue sparing. The place of IGRT following radical prostatectomy is poorly described in the literature. This review aims to highlight some key points on the different IGRT techniques applicable to prostatic bed radiotherapy. Furthermore, methods used to evaluate target motion and to reduce planning target volume margins will also be explored.
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Affiliation(s)
- Florent Vilotte
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Mickael Antoine
- Department of Medical Physics, Institut Bergonié , Bordeaux Cedex , France
| | - Maxime Bobin
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Igor Latorzeff
- Department of Radiotherapy, Groupe ONCORAD, Clinique Pasteur , Toulouse , France
| | - Stéphane Supiot
- Department of Radiotherapy, Institut de Cancérologie de L'Ouest René Gauducheau , Nantes , France
| | - Pierre Richaud
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Laurence Thomas
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Nicolas Leduc
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Stephane Guérif
- Department of Radiotherapy, CHU de Poitier , Poitiers , France
| | | | | | - Paul Sargos
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
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Abstract
Asthma is one of the most prevalent chronic diseases managed by school nurses, and its management often includes the administration of bronchodilators delivered via a metered dose inhaler (MDI). The use of an MDI requires coordination and mastery of steps that must be performed correctly and in the proper order. These steps are greatly enhanced, especially in the pediatric population, through the use of medical devices-spacers and valved holding chambers. The purpose of this article is to review the rationale and implications for the use of these devices in the school setting.
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Affiliation(s)
| | - Tonya Winders
- President and Chief Executive Officer, Allergy & Asthma Network, Vienna, VA
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24
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Abstract
Aerosolized medications are routinely used for the treatment of critically ill patients. This paper reviews aerosol delivery devices with a focus on issues related to their performance in pulmonary critical care. Factors affecting aerosol drug delivery to mechanically ventilated adults and spontaneously breathing patients with artificial airways are reviewed. Device selection, optimum device technique, and unmet medical needs of aerosol medicine in pulmonary critical care are also discussed.
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Affiliation(s)
- Arzu Ari
- Division of Respiratory Therapy, Georgia State University, Atlanta, Georgia.
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25
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Aggarwal B, Gogtay J. Use of pressurized metered dose inhalers in patients with chronic obstructive pulmonary disease: review of evidence. Expert Rev Respir Med 2014; 8:349-56. [PMID: 24802511 DOI: 10.1586/17476348.2014.905916] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The inhaled route is considered to be the best route to administer drugs for treating respiratory diseases like asthma and chronic obstructive pulmonary disease (COPD), for both safety and efficacy. Inhalation devices are classified into four types - pressuriszed metered dose inhalers (pMDIs), dry powder inhalers, breath actuated inhalers and nebulizers. pMDIs are portable, convenient, multi-dose devices and these advantages have made them very popular with patients. They were introduced in the 1950s as the first portable, multi-dose delivery system for bronchodilators. Even though pMDIs are the most widely used devices for inhalation therapy in asthma and COPD, studies establishing their use and providing clinical data with bronchodilators and combination therapies in patients with COPD are limited. A summary of the use of pMDI with spacers in patients with COPD in terms of lung deposition and impact on lung function are presented in this review article. A review of use of the pMDI device in patients with COPD with different available and prescribed medications (bronchodilators-β2-agonists and anticholinergics, and their combination with inhaled corticosteroids) is discussed.
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26
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Bien DCS, Lee HW, Badaruddin SAM. Formation of silicon nanostructures with a combination of spacer technology and deep reactive ion etching. Nanoscale Res Lett 2012; 7:288. [PMID: 22672745 PMCID: PMC3502542 DOI: 10.1186/1556-276x-7-288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 05/24/2012] [Indexed: 05/31/2023]
Abstract
A new method of fabricating high aspect ratio nanostructures in silicon without the use of sub-micron lithographic technique is reported. The proposed method comprises two important steps including the use of CMOS spacer technique to form silicon nitride nanostructure masking followed by deep reactive ion etching (DRIE) of the silicon substrate to form the final silicon nanostructures. Silicon dioxide is used as the sacrificial layer to form the silicon nitride nanostructures. With DRIE a high etch selectivity of 50:1 between silicon and silicon nitride was achieved. The use of the spacer technique is particularly advantageous where self-aligned nanostructures with potentially unlimited lengths are formed without the need of submicron lithographic tools and resist materials. With this method, uniform arrays of 100 nm silicon nanostructures which are at least 4 μm tall with aspect ratio higher than 40 were successfully fabricated.
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Affiliation(s)
- Daniel CS Bien
- Nanoelectronics Cluster, MIMOS Berhad, Technology Park Malaysia, Kuala Lumpur 57000, Malaysia
| | - Hing Wah Lee
- Nanoelectronics Cluster, MIMOS Berhad, Technology Park Malaysia, Kuala Lumpur 57000, Malaysia
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27
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Abstract
Infection after total hip arthroplasties (THA) is a devastating complication with significant consequences for both the patients and the healthcare systems. In recent times, a two stage procedure using antibiotic-impregnated interim spacers has become the most popular treatment for late chronic hip joint infections after THA with success rates over 90%. In this review, we discuss the different types of spacers used in the treatment of chronically infected THA and conclude that hip spacers are effective in the treatment of hip joint infections.
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Affiliation(s)
- Mohamed Sukeik
- Department of Orthopaedics, University College London Hospital, 235 Euston Road, London, NW1 2BU, United Kingdom.
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28
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Lavorini F, Geri P, Mariani L, Marmai C, Maluccio NM, Pistolesi M, Fontana GA. Speed of onset of bronchodilator response to salbutamol inhaled via different devices in asthmatics: a bioassay based on functional antagonism. Br J Clin Pharmacol 2006; 62:403-11. [PMID: 16995861 PMCID: PMC1885153 DOI: 10.1111/j.1365-2125.2006.02641.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Accepted: 01/24/2006] [Indexed: 11/28/2022] Open
Abstract
AIMS To evaluate the speed of onset of bronchodilation following salbutamol administered via a metered-dose inhaler with a spacer (pMDI + Volumatic) and a dry-powder inhaler (Diskus), as well as the relative potencies of these devices in asthmatic patients with methacholine-induced bronchoconstriction. METHODS Eighteen patients inhaled methacholine (MCh) until FEV(1) decreased by 35% of control. Following administration of placebo, 200 microg salbutamol or 400 microg salbutamol through the pMDI + Volumatic or the Diskus, we calculated the time elapsed from drug administration and the appearance of a 90% increase in post-MCh forced vital capacity (FVC), FEV(1) and volume-adjusted mid-expiratory flow (recovery times). The salbutamol doses to be delivered by the two inhalation devices to achieve similar recovery times and the relative potencies of the devices were calculated by using the 2-by-2 Finney parallel regression method. RESULTS For all functional variables, recovery times were significantly (P < 0.01) shorter in pMDI + Volumatic than Diskus trials. The salbutamol doses to be delivered by the Diskus to achieve recovery times for FVC, FEV(1) and volume-adjusted mid-expiratory flow similar to those obtained with 200 microg salbutamol administered via the pMDI + Volumatic were 558 (95% CI 537, 579) microg, 395 (95% CI 388, 404) microg and 404 (95% CI 393, 415) microg, respectively, and corresponded to relative potencies of 2.79 (95% CI 2.68, 2.90), 1.98 (95% CI 1.94, 2.02), and 2.02 (95% CI 1.96, 2.07). CONCLUSIONS Administration of salbutamol via the pMDI + Volumatic provides faster reversal of induced bronchoconstriction than via the Diskus. The salbutamol dose targeting the lungs with the pMDI + Volumatic is approximately twice that with the Diskus.
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Affiliation(s)
- Federico Lavorini
- Dipartimento di Area Critica Medico Chirurgica, Unità Funzionale di Medicina Respiratoria, Università degli Studi di Firenze, Italia.
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