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| 2. |
- Dev, Apurba, et al.
(författare)
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Electrokinetic effect for molecular recognition : A label-free approach for real-time biosensing
- 2016
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Ingår i: Biosensors & bioelectronics. - : Elsevier. - 0956-5663 .- 1873-4235. ; 82, s. 55-63
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Tidskriftsartikel (refereegranskat)abstract
- We present a simple and inexpensive method for label-free detection of biomolecules. The method monitors the changes in streaming current in a fused silica capillary as target biomolecules bind to immobilized receptors on the inner surface of the capillary. To validate the concept, we show detection and time response of different protein-ligand and protein-protein systems: biotin-avidin and biotin-streptavidin, barstar-dibarnase and Z domain-immunoglobulin G (IgG). We show that specific binding of these biomolecules can be reliably monitored using a very simple setup. Using sequential injections of various proteins at a diverse concentration range and as well as diluted human serum we further investigate the capacity of the proposed technique to perform specific target detection from a complex sample. We also investigate the time for the signal to reach equilibrium and its dependence on analyte concentration and demonstrate that the current setup can be used to detect biomolecules at a concentration as low as 100 pM without requiring any advanced device fabrication procedures. Finally, an analytical model based on diffusion theory has been presented to explain the dependence of the saturation time on the analyte concentration and capillary dimensions and how reducing length and inner diameter of the capillary is predicted to give faster detection and in practice also lower limit of detection.
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| 3. |
- Lundgren, Fredrik, et al.
(författare)
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PTFE bypass to below-knee arteries : distal vein collar or not? A prospective randomised multicentre study
- 2010
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 39:6, s. 747-754
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPatency and limb salvage after synthetic bypass to the arteries below-knee are inferior to that which can be achieved with autologous vein. Use of a vein collar at the distal anastomosis has been suggested to improve patency and limb salvage, a problem that is analysed in this randomised clinical study.MethodsPatients with critical limb ischaemia undergoing polytetrafluoroethylene (PTFE) bypass to below-knee arteries were randomly either assigned a vein collar or not in two groups – bypass to the popliteal artery below-knee (femoro-popliteal below-knee (FemPopBK)) and more distal bypass (femoro-distal bypass (FemDist)). Follow-up was scheduled until amputation, death or at most 5 years, whichever event occurred first.ResultsIn the FemPopBK and in the FemDist groups, 115/202 and 72/150 were randomised to have a vein collar, respectively. Information was available for 345 of 352 randomised patients (98%).At 3 years, primary patency was 26% (95% confidence interval (CI) 18–38) with a vein collar and 43 (33–58) without a vein collar for femoro-popliteal bypass and 20 (11–38), and 17 (9–33) for femoro-distal bypass, respectively. The corresponding figures for limb salvage were 64 (54–75) and 61 (50–74) for femoro-popliteal bypass, and 59 (46–76) and 44 (32–61) for femoro-distal bypass with and without a vein collar, respectively. Log-rank-test for the whole Kaplan–Meier life table curve showed no statistically significant differences with or without vein collar primary patency: p = 0.0853, p = 0.228; secondary patency: p = 0.317, p = 0.280; limb salvage: p = 0.757, p = 0.187 for FemPopBK and FemDist, respectively. The use of a vein collar did not influence patency or limb salvage.ConclusionThis study failed to show any benefit for vein collar with PTFE bypass to a below-knee artery.
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| 4. |
- Yndigegn, T., et al.
(författare)
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Beta-Blockers after Myocardial Infarction and Preserved Ejection Fraction
- 2024
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Ingår i: New England Journal of Medicine. - : MASSACHUSETTS MEDICAL SOC. - 0028-4793 .- 1533-4406.
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Tidskriftsartikel (refereegranskat)abstract
- Background Most trials that have shown a benefit of beta-blocker treatment after myocardial infarction included patients with large myocardial infarctions and were conducted in an era before modern biomarker-based diagnosis of myocardial infarction and treatment with percutaneous coronary intervention, antithrombotic agents, high-intensity statins, and renin-angiotensin-aldosterone system antagonists.Methods In a parallel-group, open-label trial performed at 45 centers in Sweden, Estonia, and New Zealand, we randomly assigned patients with an acute myocardial infarction who had undergone coronary angiography and had a left ventricular ejection fraction of at least 50% to receive either long-term treatment with a beta-blocker (metoprolol or bisoprolol) or no beta-blocker treatment. The primary end point was a composite of death from any cause or new myocardial infarction.Results From September 2017 through May 2023, a total of 5020 patients were enrolled (95.4% of whom were from Sweden). The median follow-up was 3.5 years (interquartile range, 2.2 to 4.7). A primary end-point event occurred in 199 of 2508 patients (7.9%) in the beta-blocker group and in 208 of 2512 patients (8.3%) in the no-beta-blocker group (hazard ratio, 0.96; 95% confidence interval, 0.79 to 1.16; P=0.64). Beta-blocker treatment did not appear to lead to a lower cumulative incidence of the secondary end points (death from any cause, 3.9% in the beta-blocker group and 4.1% in the no-beta-blocker group; death from cardiovascular causes, 1.5% and 1.3%, respectively; myocardial infarction, 4.5% and 4.7%; hospitalization for atrial fibrillation, 1.1% and 1.4%; and hospitalization for heart failure, 0.8% and 0.9%). With regard to safety end points, hospitalization for bradycardia, second- or third-degree atrioventricular block, hypotension, syncope, or implantation of a pacemaker occurred in 3.4% of the patients in the beta-blocker group and in 3.2% of those in the no-beta-blocker group; hospitalization for asthma or chronic obstructive pulmonary disease in 0.6% and 0.6%, respectively; and hospitalization for stroke in 1.4% and 1.8%.Conclusions Among patients with acute myocardial infarction who underwent early coronary angiography and had a preserved left ventricular ejection fraction (>= 50%), long-term beta-blocker treatment did not lead to a lower risk of the composite primary end point of death from any cause or new myocardial infarction than no beta-blocker use. (Funded by the Swedish Research Council and others; REDUCE-AMI ClinicalTrials.gov number, NCT03278509.) Hospitalized patients with acute myocardial infarction and preserved EF were assigned to receive open-label long-term beta-blocker therapy or not. Beta-blockers did not lead to a lower risk of death or MI.
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| 5. |
- Baker, K., et al.
(författare)
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Automated respiratory rate counter to assess children for symptoms of pneumonia: Protocol for cross-sectional usability and acceptability studies in Ethiopia and Nepal
- 2020
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Ingår i: JMIR Research Protocols. - : JMIR Publications Inc.. - 1929-0748. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Manually counting a child's respiratory rate (RR) for 60 seconds using an acute respiratory infection timer is the World Health Organization (WHO) recommended method for detecting fast breathing as a sign of pneumonia. However, counting the RR is challenging and misclassification of an observed rate is common, often leading to inappropriate treatment. To address this gap, the acute respiratory infection diagnostic aid (ARIDA) project was initiated in response to a call for better pneumonia diagnostic aids and aimed to identify and assess automated RR counters for classifying fast breathing pneumonia when used by front-line health workers in resource-limited community settings and health facilities. The Children's Automated Respiration Monitor (ChARM), an automated RR diagnostic aid using accelerometer technology developed by Koninklijke Philips NV, and the Rad-G, a multimodal RR diagnostic and pulse oximeter developed by Masimo, were the two devices tested in these studies conducted in the Southern Nations, Nationalities, and Peoples' Region in Ethiopia and in the Karnali region in Nepal. Objective: In these studies, we aimed to understand the usability of two new automated RR diagnostic aids for community health workers (CHWs; health extension workers [Ethiopia] and female community health volunteers [Nepal]) and their acceptability to CHWs in Ethiopia and Nepal, first-level health facility workers (FLHFWs) in Ethiopia only, and caregivers in both Ethiopia and Nepal. Methods: This was a prospective, cross-sectional study with a mixed methods design. CHWs and FLHFWs were trained to use both devices and provided with refresher training on all WHO requirements to assess fast breathing. Immediately after training, CHWs were observed using ARIDA on two children. Routine pneumonia case management consultations for children aged 5 years and younger and the device used for these consultations between the first and second consultations were recorded by CHWs in their patient log books. CHWs were observed a second time after 2 months. Semistructured interviews were also conducted with CHWs, FLHFWs, and caregivers. The proportion of consultations with children aged 5 years and younger where CHWs using an ARIDA and adhered to all WHO requirements to assess fast breathing and device manufacturer instructions for use after 2 months will be calculated. Qualitative data from semistructured interviews will be analyzed using a thematic framework approach. Results: The ARIDA project was funded in November 2015, and data collection was conducted between April and December 2018. Data analysis is currently under way and the first results are expected to be submitted for publication in 2020. Conclusions: This is the first time the usability and acceptability of automated RR counters in low-resource settings have been evaluated. Outcomes will be relevant for policy makers and are important for future research of this new class of diagnostic aids for the management of children with suspected pneumonia. © Kevin Nicholas Baker, Alice Maurel, Charlotte Ward, Dawit Getachew, Tedila Habte, Cindy McWhorter, Paul LaBarre, Jonas Karlström, Max Petzold, Karin Källander.
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| 9. |
- Björling, Mikael, et al.
(författare)
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Conformational adaption of poly(ethylene oxide). A 13C NMR study
- 1991
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Ingår i: Journal of Physical Chemistry. - 0022-3654. ; 95:17, s. 6706-6709
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Tidskriftsartikel (refereegranskat)abstract
- The 13C NMR chemical shift was used as a probe for the average partition of rotational conformers around the C-C bond in the O-CH2-CH2-O segments of polyethylene oxide). Dividing the conformers into a large group of trans and a smaller group of gauche conformers, we concluded that the trans conformers have a higher (downfield) average chemical shift than the gauche conformers. The shift of the main PEO 13C line with changing environment was interpreted as an adaption in the partition between the two groups of conformers. Furthermore, the trans conformers had nonpolar character and were favored at high temperatures, whereas the gauche conformers had polar character. The measurements were compared to the predictions of a model proposed by Karlström, and a semiquantitative agreement was found.
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| 10. |
- Björling, Mikael, et al.
(författare)
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Distribution of segments for terminally attached poly(ethylene oxide) chains
- 1990
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Ingår i: Journal of Physical Chemistry. - 0022-3654. ; 94:1, s. 471-481
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Tidskriftsartikel (refereegranskat)abstract
- A theory for describing the equilibrium ethylene oxide (EO) segment distribution for terminally attached poly(ethylene oxide) (PEO) chains is presented. It is based on Scheutjens and Fleer's lattice model for polymer solutions in heterogeneous systems and a two-state model for the EO segments. The two-state model provides one explanation of the solubility gap of homogeneous PEO solutions. The segment distribution is examined as a function of temperature, grafting density, and curvature. The present theory predicts distributions, which cannot be reproduced with the use of temperature-dependent interaction parameters in a one-state model. Specifically, the segments tend to be more accumulated at the surface but also far away from the surface at the expense of the intervening transition region. Calculation on a model of a micelles formed by the nonionic surfactant C 12E 8 supports the experimental conclusions that the EO segments are preferentially accumulated nearby the hydrocarbon core and not completely extended into the water region.
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