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Pasqualetto G, Mack A, Lewis E, Cooper R, Holland A, Borucu U, Mantell J, Davies T, Weckener M, Clare D, Green T, Kille P, Muhlhozl A, Young MT. CryoEM structure and Alphafold molecular modelling of a novel molluscan hemocyanin. PLoS One 2023; 18:e0287294. [PMID: 37347755 PMCID: PMC10286996 DOI: 10.1371/journal.pone.0287294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/03/2023] [Indexed: 06/24/2023] Open
Abstract
Hemocyanins are multimeric oxygen transport proteins present in the blood of arthropods and molluscs, containing up to 8 oxygen-binding functional units per monomer. In molluscs, hemocyanins are assembled in decamer 'building blocks' formed of 5 dimer 'plates', routinely forming didecamer or higher-order assemblies with d5 or c5 symmetry. Here we describe the cryoEM structures of the didecamer (20-mer) and tridecamer (30-mer) forms of a novel hemocyanin from the slipper limpet Crepidula fornicata (SLH) at 7.0 and 4.7 Å resolution respectively. We show that two decamers assemble in a 'tail-tail' configuration, forming a partially capped cylinder, with an additional decamer adding on in 'head-tail' configuration to make the tridecamer. Analysis of SLH samples shows substantial heterogeneity, suggesting the presence of many higher-order multimers including tetra- and pentadecamers, formed by successive addition of decamers in head-tail configuration. Retrieval of sequence data for a full-length isoform of SLH enabled the use of Alphafold to produce a molecular model of SLH, which indicated the formation of dimer slabs with high similarity to those found in keyhole limpet hemocyanin. The fit of the molecular model to the cryoEM density was excellent, showing an overall structure where the final two functional units of the subunit (FU-g and FU-h) form the partial cap at one end of the decamer, and permitting analysis of the subunit interfaces governing the assembly of tail-tail and head-tail decamer interactions as well as potential sites for N-glycosylation. Our work contributes to the understanding of higher-order oligomer formation in molluscan hemocyanins and demonstrates the utility of Alphafold for building accurate structural models of large oligomeric proteins.
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Affiliation(s)
- Gaia Pasqualetto
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Andrew Mack
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Emily Lewis
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Ryan Cooper
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Alistair Holland
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Ufuk Borucu
- Faculty of Life Sciences, GW4 Facility for High-Resolution Electron Cryo-Microscopy, Wolfson Bioimaging Facility, University of Bristol, Bristol, United Kingdom
| | - Judith Mantell
- Faculty of Life Sciences, GW4 Facility for High-Resolution Electron Cryo-Microscopy, Wolfson Bioimaging Facility, University of Bristol, Bristol, United Kingdom
| | - Tom Davies
- School of Chemistry, Cardiff University, Cardiff, United Kingdom
| | - Miriam Weckener
- The Rosalind Franklin Institute, Structural Biology, Harwell Science Campus, Didcot, United Kingdom
| | - Dan Clare
- Electron Bioimaging Centre, Diamond Light Source, Harwell, United Kingdom
| | - Tom Green
- Advanced Research Computing at Cardiff, Cardiff University, Cardiff, United Kingdom
| | - Pete Kille
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | - Mark T. Young
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
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Kirk R, Ratcliffe A, Noonan G, Uosis-Martin M, Lyth D, Bardell-Cox O, Massam J, Schofield P, Lyons A, Clare D, Maclean J, Smith A, Savage V, Mohmed S, Charrier C, Salisbury AM, Moyo E, Ooi N, Chalam-Judge N, Cheung J, Stokes NR, Best S, Craighead M, Armer R, Huxley A. Rational design, synthesis and testing of novel tricyclic topoisomerase inhibitors for the treatment of bacterial infections part 2. RSC Med Chem 2020; 11:1379-1385. [PMID: 34095845 PMCID: PMC8126889 DOI: 10.1039/d0md00175a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/07/2020] [Indexed: 11/21/2022] Open
Abstract
Building on our previously-reported novel tricyclic topoisomerase inhibitors (NTTIs), we disclose the discovery of REDX07965, which has an MIC90 of 0.5 μg mL-1 against Staphylococcus aureus, favourable in vitro pharmacokinetic properties, selectivity versus human topoisomerase II and an acceptable toxicity profile. The results herein validate a rational design approach to address the urgent unmet medical need for novel antibiotics.
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Affiliation(s)
- R Kirk
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - A Ratcliffe
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - G Noonan
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - M Uosis-Martin
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - D Lyth
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - O Bardell-Cox
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - J Massam
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - P Schofield
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - A Lyons
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - D Clare
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - J Maclean
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - A Smith
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - V Savage
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - S Mohmed
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - C Charrier
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - A-M Salisbury
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - E Moyo
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - N Ooi
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - N Chalam-Judge
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - J Cheung
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - N R Stokes
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - S Best
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - M Craighead
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - R Armer
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
| | - A Huxley
- Redx Anti-Infectives Ltd Alderley Park Macclesfield SK10 4TG Cheshire UK
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Walker J, Marzec B, Ozaki N, Clare D, Nudelman F. Morphological development of Pleurochrysis carterae coccoliths examined by cryo-electron tomography. J Struct Biol 2020; 210:107476. [DOI: 10.1016/j.jsb.2020.107476] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/28/2020] [Accepted: 01/31/2020] [Indexed: 11/28/2022]
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McMullan G, Faruqi AR, Clare D, Henderson R. Comparison of optimal performance at 300keV of three direct electron detectors for use in low dose electron microscopy. Ultramicroscopy 2014; 147:156-63. [PMID: 25194828 PMCID: PMC4199116 DOI: 10.1016/j.ultramic.2014.08.002] [Citation(s) in RCA: 208] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/30/2014] [Accepted: 08/03/2014] [Indexed: 11/29/2022]
Abstract
Low dose electron imaging applications such as electron cryo-microscopy are now benefitting from the improved performance and flexibility of recently introduced electron imaging detectors in which electrons are directly incident on backthinned CMOS sensors. There are currently three commercially available detectors of this type: the Direct Electron DE-20, the FEI Falcon II and the Gatan K2 Summit. These have different characteristics and so it is important to compare their imaging properties carefully with a view to optimise how each is used. Results at 300 keV for both the modulation transfer function (MTF) and the detective quantum efficiency (DQE) are presented. Of these, the DQE is the most important in the study of radiation sensitive samples where detector performance is crucial. We find that all three detectors have a better DQE than film. The K2 Summit has the best DQE at low spatial frequencies but with increasing spatial frequency its DQE falls below that of the Falcon II. Three direct electron detectors offer better DQE than film at 300 keV. Recorded 300 keV electron events on the detectors have very similar Landau distributions. The Gatan K2 Summit detector has the highest DQE at low spatial frequency. The FEI Falcon II detector has the highest DQE beyond one half the Nyquist frequency. The Direct Electron DE-20 detector has the fastest data acquisition rate.
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Affiliation(s)
- G McMullan
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom.
| | - A R Faruqi
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - D Clare
- Crystallography and Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, United Kingdom
| | - R Henderson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
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Nyhan R, Ferrando MB, Clare D. A population ecology study of hospital closures in Florida between 1965 and 1995. J Health Hum Serv Adm 2001; 24:295-319. [PMID: 14998286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The population ecology literature argues that, at the macro level, organizations experience various liabilities to their continued survival. This study examined the effect of size, age, and niche density on the closure of acute care hospitals in Florida between 1965 and 1995. The data for the study were created using information about Florida hospitals found in the annual reports of the American Hospital Association (n = 427). Using the technique of survival analysis, it was found that newer hospitals and hospitals originally established in organizationally dense areas (five or more hospitals within a five-mile radius) experienced a significantly greater incidence of closure than did those that were older or founded in less dense areas. Small hospitals (<100 beds) were also shown to be significantly more likely to close than large ones (>300 beds) as were hospitals located in organizationally dense areas (>five hospitals in a five-mile radius). The study concludes with an examination of the policy and management implications of the results.
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Affiliation(s)
- R Nyhan
- Florida Atlantic University, USA
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Abstract
We have built a device for use within the hospital and at home that is designed to warn of circuit disconnection when used in conjunction with continuous positive airway pressure (CPAP) therapy delivered via ventilators or CPAP generating systems. The Royal Children's Hospital CPAP alarm is a compact, battery operated alarm and monitor of circuit pressure. The device includes intrinsic safety features including a safety blow-off valve, a high pressure alarm and design features that make the device practical, safe and easy to use by both trained hospital personnel and home care attendants with limited training.
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Affiliation(s)
- B Carter
- Anaesthetic Department, Royal Children's Hospital, Parkville, Victoria
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Abstract
Seventy neonatal to adolescent general surgical patients were studied to create an individual dose-response curve for the long-acting neuromuscular blocking agents, alcuronium and d-tubocurarine. The mean (SEM) ED95 of alcuronium was 196 (9), 271 (13) and 243 (8) micrograms/kg in infants, children and adolescents, respectively (P less than 0.01). d-tubocurarine showed a similar age dependent dose-response relationship. ED95 doses were 414 (40), 499 (41) and 445 (31) micrograms/kg, respectively. The onset time (time from intravenous administration to maximal effect) following equipotent dosages was 40-50% shorter in infants than in children or adolescents (1.5 vs 2.7 minutes, P less than 0.05).
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Affiliation(s)
- O A Meretoja
- Department of Anaesthesia, Royal Children's Hospital, Melbourne
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Abstract
The rate of onset of action of d-tubocurarine (64 patients) or alcuronium (36 patients) was studied electromyographically in 100 children who had abdominal, bone or cerebral tumours. It was found that there was a significantly delayed onset (over three times longer than controls) or additional doses were required in patients with malignant liver, renal and bone tumours who received d-tubocurarine. The onset of alcuronium blockade was also prolonged but to a lesser extent. When tumours with an abnormal prolongation of onset of relaxation were successfully treated by chemotherapy and/or surgery, the response reverted to normal. Children with benign tumours or masses had normal responses. In contrast, neuroblastomas were associated with little prolongation of onset. Cerebral tumours showed a variable response, with the observed changes being unreliable indicators of degree of malignancy.
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Affiliation(s)
- T C Brown
- Department of Anaesthesia, Royal Children's Hospital, Melbourne, Victoria, Australia
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Brown TC, Meretoja OA, Bell B, Clare D. Responses to small doses of suxamethonium in four children with abnormal cholinesterase--a case report. Anaesth Intensive Care 1990; 18:477-8. [PMID: 2268012 DOI: 10.1177/0310057x9001800410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Four patients with genetic cholinesterase abnormalities were studied with electromyography after being given suxamethonium 0.1 mg/kg. An abnormal homozygous patient was paralysed for 17 minutes. The duration of response in heterozygous patients was 2-4 minutes, being shorter when cholinesterase activity levels were near normal.
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Affiliation(s)
- T C Brown
- Department of Anaesthesia, Royal Children's Hospital, Melbourne, Victoria, Australia
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Abstract
Suxamethonium was administered to 225 children aged from one to sixteen years, in doses varying from 0.1 to 0.5 mg/kg. Dose responses were determined. ED95 was 445 micrograms/kg in one to four year olds, 454 micrograms/kg in the five to ten years group and 270 micrograms/kg in eleven to fifteen year olds (P less than 0.05). There is a wider variability in patient responses to 0.1 and 0.2 mg/kg than to the higher doses. Sixty-two children in the three age groups were given suxamethonium 1 mg/kg. The time from injection to maximum block and to 50% recovery increased with increasing age (P less than 0.05).
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Affiliation(s)
- T C Brown
- Department of Anaesthesia, Royal Children's Hospital, Melbourne, Victoria, Australia
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Brown TC, Meretoja OA, Clare D, Bell B. Does suxamethonium influence the subsequent dose requirements of alcuronium and its reversibility in children? Anaesth Intensive Care 1990; 18:479-82. [PMID: 2268013 DOI: 10.1177/0310057x9001800411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Suxamethonium is often used for intubation prior to the use of a nondepolarizing muscle relaxant. This study was performed to determine whether suxamethonium altered the dose of alcuronium required to produce neuromuscular block. The findings were that suxamethonium 1.0 mg/kg did not alter the depth, duration or reversibility of block if given before alcuronium 0.3 mg/kg. Reversal with neostigmine was more rapid following 50 micrograms/kg than after 25 micrograms/kg. If recovery from neuromuscular block was greater than 25 per cent, the lower dose produced satisfactory reversal, whether or not suxamethonium had been given previously.
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Affiliation(s)
- T C Brown
- Royal Children's Hospital, Parkville, Victoria, Australia
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Brunton J, Meier M, Erhman N, Clare D, Almawy R. Origin of small beta-lactamase-specifying plasmids in Haemophilus species and Neisseria gonorrhoeae. J Bacteriol 1986; 168:374-9. [PMID: 3020002 PMCID: PMC213461 DOI: 10.1128/jb.168.1.374-379.1986] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Fifty-nine percent of unselected strains of Haemophilus parainfluenzae were found to carry small, phenotypically cryptic plasmid DNA species. Using filter blot hybridization, we found several plasmids which were homologous to the small beta-lactamase-specifying plasmids pJB1 and pFA7, which were originally isolated from Haemophilus ducreyi and Neisseria gonorrhoeae, respectively. Detailed filter hybridization studies combined with electron microscope heteroduplex analysis suggested that three cryptic plasmids are completely homologous to the non-TnA sequences of pJB1. One cryptic plasmid was found to be highly homologous to pJB603, a small beta-lactamase plasmid previously found in two isolates of H. influenzae. A second group of plasmids were found to carry sequences homologous to pJB1 and other sequences homologous to pJB603. These results strongly suggest that small beta-lactamase plasmids found in Haemophilus species and N. gonorrhoeae may have arisen by insertion of the transposable beta-lactamase-specifying element TnA into small, phenotypically cryptic replicons resident in H. parainfluenzae. Attempts to reproduce such a recombination event in the laboratory were not successful.
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Brunton J, Clare D, Meier MA. Molecular epidemiology of antibiotic resistance plasmids of Haemophilus species and Neisseria gonorrhoeae. Rev Infect Dis 1986; 8:713-24. [PMID: 3024290 DOI: 10.1093/clinids/8.5.713] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Ampicillin resistance in Haemophilus influenzae and Neisseria gonorrhoeae is most commonly due to plasmid-mediated production of the TEM beta-lactamase. The H. influenzae plasmids may have evolved by insertion of various antibiotic resistance transposons into a phenotypically cryptic plasmid found in one of 699 isolates of H. influenzae examined. The small, nonconjugative, beta-lactamase-specifying plasmids of N. gonorrhoeae and Haemophilus species are highly related. Phenotypically cryptic plasmids found in several epidemiologically distinct isolates of Haemophilus parainfluenzae are highly related to the beta-lactamase plasmids but carry no transposon A (TnA) sequences. This evidence strongly favors the hypothesis that the beta-lactamase plasmids evolved by the insertion of TnA (possibly introduced from enteric bacteria) into cryptic plasmids resident in H. parainfluenzae.
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Abstract
Micro-ID is a new test system designed to identify members of the family Enterobacteriaceae in 4 h. It consists of 15 biochemical tests on reagent-impregnated paper disks; each test is in its own compartment in a molded plastic tray. Based on the pattern of positive and negative biochemical reactions, a five-digit octal code number is calculated. A computer-generated identification manual accompanies the product, and for each octal code listed there is a numerical value that represents the unknown isolate's degree of fit to a typical organism (LFR), a second numerical value that represents its separation from other organisms (PNOR), and a verbal description of the quality of identification. Only one reagent is added to the system. Manufacturer's directions were modified in this laboratory to allow identification from a turbid blood culture bottle within 4 h. Based on 330 routine clinical cultures tested, there was a 96.1% agreement with conventional identification to the genus and species level: 1.2% yielded first two choices possible, with one being the correct choice; 1.2% provided a correct genus, but no species identification; and 1.5% produced an incorrect identification. The Micro-ID is an accurate, facile system for the rapid identification of Enterobacteriaceae from blood cultures.
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Zollinger RM, Field JB, Hamwi GJ, Clare D, Wilde RC. Surgery of endocrine glands with emphasis on diseases of the thyroid. Postgrad Med 1965; 38:333-44. [PMID: 5827650 DOI: 10.1080/00325481.1965.11696803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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