ResearchPad - technical-advance https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Feasibility of pulmonary MRI for nodule detection in comparison to computed tomography]]> https://www.researchpad.co/article/elastic_article_9894 To assess the feasibility of various magnetic resonance imaging (MRI) sequences for the detection of pulmonary nodules by comparing the detection rate of computed tomography (CT).MethodsForty-two patients with pulmonary nodules detected by multi-slice CT (MSCT) were prospectively enrolled in the present study between November 2016 and February 2017. Chest MRI was acquired within 24 h of CT. The MRI protocol included free-breathing radial VIBE (r-VIBE) and a conventional breathhold T1-weighted VIBE (C-VIBE) were analyzed by two independent radiologists. Both detection and morphology results of each MRI image were recorded. Subjective image evaluation in terms of overall nodule morphology on the MRI images was carried out using the 4-point scoring criteria. The MRI results were compared with those from CT, with the results of MSCT serving as the reference standard.ResultsTwo hundred and fifty-eight solid pulmonary nodules in 42 patients were detected by CT. The r-VIBE correctly detected 94% of the pulmonary nodules as compared with CT. The detection rate increased to 100% for lesions ≥6 mm. The C-VIBE had a lower overall detection rate (64.3%) of pulmonary nodules. The difference in the subjective image evaluation scores between the two sequences was statistically significant (p < 0.001).ConclusionSignificantly increased detection rates were obtained with free-breathing r-VIBE as compared with C-VIBE for the detection of pulmonary nodules and also provided more information when evaluating the nodules as compared with C-VIBE. ]]> <![CDATA[Combining GAL4 GFP enhancer trap with split luciferase to measure spatiotemporal promoter activity in Arabidopsis]]> https://www.researchpad.co/article/elastic_article_6937 Cell and tissue type resolution of gene expression is important to understand functional properties of signalling networks. We have adapted a split luciferase system for use with existing collections of enhancer trap lines to provide a versatile tool to detect dynamic tissue‐specific gene expression in whole Arabidopsis seedlings and demonstrate its utility to detect spatial heterogeneity of circadian rhythms in leaves.

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<![CDATA[Feasibility of using an led-probe in third-space endoscopy: a clinical study]]> https://www.researchpad.co/article/N1dbc60c3-c0fc-4c7c-a98d-5b08819a7846 Third-space endoscopy is a novel, safe, and effective method for treating different gastrointestinal conditions. However, several failed endoscopic procedures are attributed to incomplete myotomy. Lighting devices are used to prevent organic injuries. We aimed to investigate the feasibility of using a hand-made LED-probe (LP) in third-space procedures.MethodsThis prospective study was conducted in a tertiary-care center in Mexico between December 2016 and January 2019. We included peroral endoscopic myotomy (POEM) and gastric peroral endoscopic myotomy(G-POEM) procedures. Pseudoachalasia, peptic ulcer, normal gastric emptying scintigraphy (GES) and prepyloric tumors were excluded. LP was used to guide or confirm procedures. Clinical and procedural characteristics were recorded and analyzed.ResultsSeventy third-space procedures were included (42POEM,28G-POEM), with an average patient age of 46.7 ± 14.3 and 43.7 ± 10.1 years, respectively. For the POEM and G-POEM groups, respectively, 18/42(42.9%) and 13/28(46.7%) patients were males; median procedure times were 50 (interquartile range [IQR]: 38–71) and 60(IQR: 48–77) min, median LP placement times were 5(IQR: 4-6) and 6(IQR: 5-7) min, mild adverse events occurred in 4(9.4%) and 4(14.2%) of cases, and clinical success at 6 months occurred in 100 and 85.7% of cases. Integrated relaxation pressure (IRP) improved from 27.3 ± 10.8 to 9.5 ± 4.1 mmHg (p < 0.001); retention percentage at 4 h also improved. LP was successfully placed and adequate myotomy confirmed including 14.2 and 17.8% of POEM and G-POEM difficult patients.ConclusionsUsing an LP is promising and allows guiding during third-space procedures either for submucosal tunnel creation or myotomy confirmation, with excellent safety and efficacy in clinical practice. ]]> <![CDATA[Therapeutic effect of intraductal saline irrigation in chronic obstructive sialadenitis]]> https://www.researchpad.co/article/Nea9b4e76-8291-4115-af18-22fe51175045

Background

The aim of the present study was to evaluate the effectiveness of intraductal irrigation using normal saline in chronic obstructive sialadenitis.

Methods

Patients who had one of the following symptoms were recruited: pain, swelling, stiffness, and dry mouth. A total of 58 salivary glands in 33 patients were diagnosed as having sialadenitis using sialography and ultrasonography. The patients were divided into two groups (swelling group and dry mouth group), according to the major complaint. Repeated intraductal irrigation was performed on each gland. Difference of symptom severity evaluated using numerical rating scale (NRS), and ductal width measured using ultrasonography were compared between the two groups.

Results

The average NRS score was significantly decreased from 6.0 to 3.3 after 3–5 visits of intraductal irrigation (P < 0.05). The reduction in NRS was greater in the swelling group than in the dry mouth group, although the difference between the groups was not statistically significant. There was no change of ductal width before and after the irrigation.

Conclusions

Intraductal irrigation according to this study method using normal saline is a simple treatment for the patients with chronic obstructive sialadenitis. It provides a conservative treatment option reducing the subjective symptoms.

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<![CDATA[Taking multi-morbidity into account when attributing DALYs to risk factors: comparing dynamic modeling with the GBD2010 calculation method]]> https://www.researchpad.co/article/5989db57ab0ee8fa60bde480

Background

Disability Adjusted Life Years (DALYs) quantify the loss of healthy years of life due to dying prematurely and due to living with diseases and injuries. Current methods of attributing DALYs to underlying risk factors fall short on two main points. First, risk factor attribution methods often unjustly apply incidence-based population attributable fractions (PAFs) to prevalence-based data. Second, it mixes two conceptually distinct approaches targeting different goals, namely an attribution method aiming to attribute uniquely to a single cause, and an elimination method aiming to describe a counterfactual situation without exposure. In this paper we describe dynamic modeling as an alternative, completely counterfactual approach and compare this to the approach used in the Global Burden of Disease 2010 study (GBD2010).

Methods

Using data on smoking in the Netherlands in 2011, we demonstrate how an alternative method of risk factor attribution using a pure counterfactual approach results in different estimates for DALYs. This alternative method is carried out using the dynamic multistate disease table model DYNAMO-HIA. We investigate the differences between our alternative method and the method used by the GBD2010 by doing additional analyses using data from a synthetic population in steady state.

Results

We observed important differences between the outcomes of the two methods: in an artificial situation where dynamics play a limited role, DALYs are a third lower as compared to those calculated with the GBD2010 method (398,000 versus 607,000 DALYs). The most important factor is newly occurring morbidity in life years gained that is ignored in the GBD2010 approach. Age-dependent relative risks and exposures lead to additional differences between methods as they distort the results of prevalence-based DALY calculations, but the direction and magnitude of the distortions depend on the particular situation.

Conclusions

We argue that the GBD2010 approach is a hybrid of an attributional and counterfactual approach, making the end result hard to understand, while dynamic modelling uses a purely counterfactual approach and thus yields better interpretable results.

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<![CDATA[Feasibility of using an led-probe in third-space endoscopy: a clinical study]]> https://www.researchpad.co/article/Nad083755-f861-4b53-8878-5ffee0faad97

Background

Third-space endoscopy is a novel, safe, and effective method for treating different gastrointestinal conditions. However, several failed endoscopic procedures are attributed to incomplete myotomy. Lighting devices are used to prevent organic injuries. We aimed to investigate the feasibility of using a hand-made LED-probe (LP) in third-space procedures.

Methods

This prospective study was conducted in a tertiary-care center in Mexico between December 2016 and January 2019. We included peroral endoscopic myotomy (POEM) and gastric peroral endoscopic myotomy(G-POEM) procedures. Pseudoachalasia, peptic ulcer, normal gastric emptying scintigraphy (GES) and prepyloric tumors were excluded. LP was used to guide or confirm procedures. Clinical and procedural characteristics were recorded and analyzed.

Results

Seventy third-space procedures were included (42POEM,28G-POEM), with an average patient age of 46.7 ± 14.3 and 43.7 ± 10.1 years, respectively. For the POEM and G-POEM groups, respectively, 18/42(42.9%) and 13/28(46.7%) patients were males; median procedure times were 50 (interquartile range [IQR]: 38–71) and 60(IQR: 48–77) min, median LP placement times were 5(IQR: 4-6) and 6(IQR: 5-7) min, mild adverse events occurred in 4(9.4%) and 4(14.2%) of cases, and clinical success at 6 months occurred in 100 and 85.7% of cases. Integrated relaxation pressure (IRP) improved from 27.3 ± 10.8 to 9.5 ± 4.1 mmHg (p < 0.001); retention percentage at 4 h also improved. LP was successfully placed and adequate myotomy confirmed including 14.2 and 17.8% of POEM and G-POEM difficult patients.

Conclusions

Using an LP is promising and allows guiding during third-space procedures either for submucosal tunnel creation or myotomy confirmation, with excellent safety and efficacy in clinical practice.

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<![CDATA[Feasibility of non-invasive Foetal electrocardiography in a twin pregnancy]]> https://www.researchpad.co/article/N479d0ffb-3588-450b-8ef7-cb1be27d2773

Background

Twin pregnancy is associated with increased perinatal mortality. Close foetal monitoring is therefore warranted. Doppler Ultrasound cardiotocography is currently the only available method to monitor both individual foetuses. Unfortunately, the performance measures of this method are poor and erroneous monitoring of the same twin with both transducers may occur, leaving the second twin unmonitored. In this study we aimed to determine the feasibility of monitoring both foetuses simultaneously in twin gestation by means of non-invasive foetal electrocardiography (NI-fECG), using an electrode patch on the maternal abdomen.

Methods

A NI-fECG recording was performed at 25 + 3 weeks of gestation on a multiparous woman pregnant with dichorionic diamniotic twins. An electrode patch consisting of eight adhesive electrodes was applied on the maternal abdomen, yielding six channels of bipolar electrophysiological measurements. The output was digitized and stored for offline processing. The recorded signals were preprocessed by suppression of high-frequency noise, baseline wander, and powerline interference. Secondly, the maternal ECG was subtracted and segmentation into individual ECG complexes was performed. Finally, ensemble averaging of these individual ECG complexes was performed to suppress interferences.

Results

Six different recordings were obtained from each of the six recording channels. Depending on the orientation and distance of the fetal heart with respect to each electrode, a distinction could be made between each fetus based on the morphology of the signals. Yielding of the fetal ECGs was performed manually based on the QRS complexes of each fetus.

Conclusion

NI-fECG with multiple electrodes allows for monitoring of the fetal heart rate and ECG of both individual fetuses in twin pregnancies.

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<![CDATA[Characterization of repeat arrays in ultra‐long nanopore reads reveals frequent origin of satellite DNA from retrotransposon‐derived tandem repeats]]> https://www.researchpad.co/article/Nf2a163ca-c86e-4748-b83d-c9cb669f3f01

Summary

Amplification of monomer sequences into long contiguous arrays is the main feature distinguishing satellite DNA from other tandem repeats, yet it is also the main obstacle in its investigation because these arrays are in principle difficult to assemble. Here we explore an alternative, assembly‐free approach that utilizes ultra‐long Oxford Nanopore reads to infer the length distribution of satellite repeat arrays, their association with other repeats and the prevailing sequence periodicities. Using the satellite DNA‐rich legume plant Lathyrus sativus as a model, we demonstrated this approach by analyzing 11 major satellite repeats using a set of nanopore reads ranging from 30 to over 200 kb in length and representing 0.73× genome coverage. We found surprising differences between the analyzed repeats because only two of them were predominantly organized in long arrays typical for satellite DNA. The remaining nine satellites were found to be derived from short tandem arrays located within LTR‐retrotransposons that occasionally expanded in length. While the corresponding LTR‐retrotransposons were dispersed across the genome, this array expansion occurred mainly in the primary constrictions of the L. sativus chromosomes, which suggests that these genome regions are favourable for satellite DNA accumulation.

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<![CDATA[Novel biomarker genes which distinguish between smokers and chronic obstructive pulmonary disease patients with machine learning approach]]> https://www.researchpad.co/article/N61b0e468-a930-4511-b984-64be34795d7f

Background

Chronic obstructive pulmonary disease (COPD) is combination of progressive lung diseases. The diagnosis of COPD is generally based on the pulmonary function testing, however, difficulties underlie in prognosis of smokers or early stage of COPD patients due to the complexity and heterogeneity of the pathogenesis. Computational analyses of omics technologies are expected as one of the solutions to resolve such complexities.

Methods

We obtained transcriptomic data by in vitro testing with exposures of human bronchial epithelial cells to the inducers for early events of COPD to identify the potential descriptive marker genes. With the identified genes, the machine learning technique was employed with the publicly available transcriptome data obtained from the lung specimens of COPD and non-COPD patients to develop the model that can reflect the risk continuum across smoking and COPD.

Results

The expression levels of 15 genes were commonly altered among in vitro tissues exposed to known inducible factors for earlier events of COPD (exposure to cigarette smoke, DNA damage, oxidative stress, and inflammation), and 10 of these genes and their corresponding proteins have not previously reported as COPD biomarkers. Although these genes were able to predict each group with 65% accuracy, the accuracy with which they were able to discriminate COPD subjects from smokers was only 29%.

Furthermore, logistic regression enabled the conversion of gene expression levels to a numerical index, which we named the “potential risk factor (PRF)” index. The highest significant index value was recorded in COPD subjects (0.56 at the median), followed by smokers (0.30) and non-smokers (0.02). In vitro tissues exposed to cigarette smoke displayed dose-dependent increases of PRF, suggesting its utility for prospective risk estimation of tobacco products.

Conclusions

Our experimental-based transcriptomic analysis identified novel genes associated with COPD, and the 15 genes could distinguish smokers and COPD subjects from non-smokers via machine-learning classification with remarkable accuracy. We also suggested a PRF index that can quantitatively reflect the risk continuum across smoking and COPD pathogenesis, and we believe it will provide an improved understanding of smoking effects and new insights into COPD.

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<![CDATA[Performance of plague rapid diagnostic test compared to bacteriology: a retrospective analysis of the data collected in Madagascar]]> https://www.researchpad.co/article/N599b8ffb-770f-4154-bb7d-be7a8580abe2

Background

Plague is a highly fatal disease caused by Yersinia pestis. Late diagnosis hampers disease outcome and effectiveness of control measures, induces death and disease spread. Advance on its diagnosis was the use of lateral flow rapid diagnostic test (RDT).

Methods

We assessed the performance of the plague RDT based on Y. pestis F1 antigen detection more than 15 years after its deployment in Madagascar. We compared the RDT with bacteriological culture results, using data from plague notified cases collected during the periods for which both tests were performed independently and systematically.

Results

Used with bubonic plague (BP) patient samples, RDTs had a sensitivity of 100% (95% CI: 99.7–100%), a specificity of 67% (95% CI: 64–70%) with a good agreement between bacteriology and RDT results (86%; κ = 0.70, 95% CI 0.67–0.73). For pneumonic plague (PP), RDT had a sensitivity of 100% (95% CI: 91–100%) and a specificity of 59% (95% CI: 49–68%) and concordance between the bacteriological and plague RDT results was moderate (70%; κ = 0.43, 95% CI 0.32–0.55). Analysis focusing on the 2017–2018 plague season including the unprecedented epidemic of PP showed that RDT used on BP samples still had a sensitivity of 100% (95% CI: 85–100%) and a specificity of 82% (95% CI: 48–98%) with a very good agreement with bacteriology 94% (κ = 0.86, 95% CI 0.67–1); for PP samples, concordance between the bacteriological and plague RDT results was poor (61%; κ = − 0.03, 95% CI -0.17 – 0.10).

Conclusions

RDT performance appeared to be similar for the diagnosis of BP and PP except during the 2017 PP epidemic where RDT performance was low. This RDT, with its good sensitivity on both plague clinical forms during a normal plague season, remained a potential test for alert. Particularly for BP, it may be of great value in the decision process for the initiation of therapy. However, for PP, RDT may deliver false negative results due to inconsistent sample quality. Plague diagnosis could be improved through the development of next generation of RDTs.

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<![CDATA[Iodine concentration and content measured by dual-source computed tomography are correlated to thyroid hormone levels in euthyroid patients: a cross-sectional study in China]]> https://www.researchpad.co/article/Ndcf067bd-2bc0-4888-ab60-9aa1246dae4a

Background

The aim of this study was to investigate the correlation of the dual energy CT measured iodine concentration and total iodine content with blood measured thyroid parameters.

Methods

Forty-three patients with normal thyroid function at our hospital from August 2017 to October 2019 were included in this retrospective study. Dual energy CT was used to scan the neck of thyroid patients. The mean iodine concentration and thyroid tissue volume were measured to calculate the total iodine content of the thyroid. Relevant tests of triiodothyronine (FT3), total triiodothyronine (TT3), total thyroxine (TT4), free thyroxine (FT4), and thyroid hormone (TSH) were conducted. The correlation of the thyroid mean iodine concentration and total iodine content with blood-measured thyroid function was analysed.

Result

The total iodine content in the thyroid was positively correlated with FT3 but negatively correlated with TSH. The mean iodine concentration of the thyroid was positively correlated with both FT3 and TT3.

Conclusion

The thyroid iodine content measured by dual energy CT can be used to determine the human iodine nutritional status and evaluate thyroid function, which will facilitate the diagnosis and treatment of thyroid diseases.

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<![CDATA[Conditional gene expression reveals stage‐specific functions of the unfolded protein response in the Ustilago maydis– maize pathosystem]]> https://www.researchpad.co/article/N565dd795-761e-42f6-8b94-bffd475add49

Summary

Ustilago maydis is a model organism for the study of biotrophic plant–pathogen interactions. The sexual and pathogenic development of the fungus are tightly connected since fusion of compatible haploid sporidia is prerequisite for infection of the host plant, maize (Zea mays). After plant penetration, the unfolded protein response (UPR) is activated and required for biotrophic growth. The UPR is continuously active throughout all stages of pathogenic development in planta. However, since development of UPR deletion mutants stops directly after plant penetration, the role of an active UPR at later stages of development remained to be determined. Here, we established a gene expression system for U. maydis that uses endogenous, conditionally active promoters to either induce or repress expression of a gene of interest during different stages of plant infection. Integration of the expression constructs into the native genomic locus and removal of resistance cassettes were required to obtain a wild‐type‐like expression pattern. This indicates that genomic localization and chromatin structure are important for correct promoter activity and gene expression. By conditional expression of the central UPR regulator, Cib1, in U. maydis, we show that a functional UPR is required for continuous plant defence suppression after host infection and that U. maydis relies on a robust control system to prevent deleterious UPR hyperactivation.

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<![CDATA[Linking disease registries and nationwide healthcare administrative databases: the French renal epidemiology and information network (REIN) insight]]> https://www.researchpad.co/article/Nb179b7b5-8327-4b62-81bf-94b41a464365

Background

Record linkage is increasingly used in health research worldwide. Combining the patient information available in healthcare, administrative and clinical databases broadens the research perspectives, particularly for chronic diseases. Recent guidelines highlight the need for transparency on the used record linkage processes and the extracted data to be used by researchers.

Methods

Therefore, the aim of this study was to describe the deterministic iterative approach used to link the French Epidemiology and Information Network (REIN), a French national End-Stage Renal Disease registry, with the Système National des Données de Santé (SNDS), a French nationwide medico-administrative healthcare database.

Results

Among the 22,073 patients included in the REIN registry who started renal replacement therapy between 2014 and 2015 in France, 19,223 (87.1%) were matched with patients in the SNDS database. Comparison of matched and unmatched patients confirmed the absence of any major selection bias. Then, the record linkage was evaluated using the comorbidity status (diabetes).

Conclusions

This fast and efficient method of record linkage with pseudonymized data and without unique and direct identifier might inspire other research teams. It also opens the path for new research on chronic kidney disease.

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<![CDATA[Use of gelatin puzzle phantoms to teach medical students isolated ultrasound transducer movements and fundamental concepts]]> https://www.researchpad.co/article/Necb55cbd-b2dc-4585-882e-07882d12470b

Background

Psychomotor skills related to the use of medical ultrasound are a fundamental, but often overlooked component of this ubiquitous medical imaging technology. Although discussions of image production/orientation, sonographic planes, and imaging/scanning techniques are common in existing literature, these discussions rarely address practical skills related to these basic concepts. The cognitive load of transducer movements and machine operation, in conjunction with learning the ultrasound representation of anatomy, may overwhelm a novice learner. Our goal was to develop and evaluate a set of ultrasound puzzle phantoms for students to use as they learn isolated, specific transducer movements and sonographic concepts. We intentionally created phantoms that contain objects that are likely familiar to students to reduce the cognitive load associated with simultaneously learning the ultrasound interpretation of anatomy.

Methods

This preliminary evaluation of our novel, homemade, gelatin ultrasound puzzle phantoms was performed using pretests and posttests obtained by scanning an assessment phantom, and student questionnaires. Two phases of training and testing occurred with feedback from Phase 1 allowing for refinement of the puzzles and techniques for testing. Skills taught and evaluated included probe rotation, depth assessment, sliding, and tilting.

Results

Twenty-eight students attended the Phase 1 training session with positive trends in students’ abilities to use rotation, sliding, and tilting to answer questions, while only depth showed statistically significant improvements (p = 0.021). Overall students agreed the experience a productive use of time (86%), was beneficial (93%), and would recommend to others (93%). Fifteen (54%) students returned 3 months later. There was no significant decay in skills obtained from the prior training session. In Phase 2, 134 medical students participated, and 76 (57%) completed an online questionnaire. A majority of students agreed they had a better understanding of rotation (83%), depth (80%), sliding (88%) and tilting (55%). Similar to Phase 1, many students (75%) felt the experience was beneficial.

Conclusions

This preliminary study gave us insight into student opinions, as well as information to guide future scalability and development of additional ultrasound puzzle phantoms to aid in medical student education of isolated transducer movements and sonographic concepts prior to imaging human anatomy.

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<![CDATA[Using research networks to generate trustworthy qualitative public health research findings from multiple contexts]]> https://www.researchpad.co/article/Nce8dbc73-7e7f-4d5b-ac1e-4274cc72d8d4

Background

Qualitative research networks (QRNs) bring together researchers from diverse contexts working on multi-country studies. The networks may themselves form a consortium or may contribute to a wider research agenda within a consortium with colleagues from other disciplines. The purpose of a QRN is to ensure robust methods and processes that enable comparisons across contexts. Under the Self-Testing Africa (STAR) initiative and the REACHOUT project on community health systems, QRNs were established, bringing together researchers across countries to coordinate multi-country qualitative research and to ensure robust methods and processes allowing comparisons across contexts. QRNs face both practical challenges in facilitating this iterative exchange process across sites and conceptual challenges interpreting findings between contexts. This paper distils key lessons and reflections from both QRN experiences on how to conduct trustworthy qualitative research across different contexts with examples from Bangladesh, Ethiopia, Kenya, Indonesia, Malawi, Mozambique, Zambia and Zimbabwe.

Methods

The process of generating evidence for this paper followed a thematic analysis method: themes initially identified were refined during several rounds of discussions in an iterative process until final themes were agreed upon in a joint learning process.

Results

Four guiding principles emerged from our analysis: a) explicit communication strategies that sustain dialogue and build trust and collective reflexivity; b) translation of contextually embedded concepts; c) setting parameters for contextualizing, and d) supporting empirical and conceptual generalisability. Under each guiding principle, we describe how credibility, dependability, confirmability and transferability can be enhanced and share good practices to be considered by other researchers.

Conclusions

Qualitative research is often context-specific with tools designed to explore local experiences and understandings. Without efforts to synthesise and systematically share findings, common understandings, experiences and lessons are missed. The logistical and conceptual challenges of qualitative research across multiple partners and contexts must be actively managed, including a shared commitment to continuous ‘joint learning’ by partners. Clarity and agreement on concepts and common methods and timelines at an early stage is critical to ensure alignment and focus in intercountry qualitative research and analysis processes. Building good relationships and trust among network participants enhance the quality of qualitative research findings.

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<![CDATA[Investigating marine bio‐calcification mechanisms in a changing ocean with in vivo and high‐resolution ex vivo Raman spectroscopy]]> https://www.researchpad.co/article/Nbee6e38c-7532-4137-ad3c-6f2664dc4fde

Abstract

Ocean acidification poses a serious threat to marine calcifying organisms, yet experimental and field studies have found highly diverse responses among species and environments. Our understanding of the underlying drivers of differential responses to ocean acidification is currently limited by difficulties in directly observing and quantifying the mechanisms of bio‐calcification. Here, we present Raman spectroscopy techniques for characterizing the skeletal mineralogy and calcifying fluid chemistry of marine calcifying organisms such as corals, coralline algae, foraminifera, and fish (carbonate otoliths). First, our in vivo Raman technique is the ideal tool for investigating non‐classical mineralization pathways. This includes calcification by amorphous particle attachment, which has recently been controversially suggested as a mechanism by which corals resist the negative effects of ocean acidification. Second, high‐resolution ex vivo Raman mapping reveals complex banding structures in the mineralogy of marine calcifiers, and provides a tool to quantify calcification responses to environmental variability on various timescales from days to years. We describe the new insights into marine bio‐calcification that our techniques have already uncovered, and we consider the wide range of questions regarding calcifier responses to global change that can now be proposed and addressed with these new Raman spectroscopy tools.

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<![CDATA[Digital postpartum hemorrhage management device (DPHMD)]]> https://www.researchpad.co/article/N6e6273f8-e933-492e-8b68-48e1c4ba03e5

Background

Primary postpartum hemorrhage (PPH) is an obstetric emergency caused by excessive blood loss that occurs most commonly after the placenta is delivered. PPH can lead to volume depletion, hypovolemic shock, anemia, and it is the leading cause of maternal mortality worldwide. With 470 deaths per 100,000 live births, the maternal mortality ratio in Ethiopia is one of the highest in the world. It is estimated that 94% of births occur at home in Ethiopia and that 10% of maternal deaths are attributed to PPH. Currently, physicians use visual estimation to calculate blood loss and provide fluid during delivery. This traditional method is subjective and generally inaccurate.

Method

In this project, after delivery blood loss measurement system integrated with fluid delivery and vital sign monitoring method is proposed. The collection and measurement system collects blood loss after delivery and measures the amount of blood loss. The management system continuously monitors the mother’s heart rate and blood pressure. These vital sign values are integrated with the measured blood loss to estimate the amount of IV fluid required to be delivered for the mother. The rate of IV fluid delivery is regulated by a flow rate sensor and solenoid valve.

Results

The prototype was built and undergone through different tests and iterations. The proposed device was tested for accuracy, cost effectiveness and ease to use. 91.28% accuracy has been achieved and the prototype was built with less than 210 USD.

Conclusion

The proposed design allows physicians, especially those in low resource setting, to estimate blood loss and deliver fluid accurately. This helps to reduce maternal mortality rate that may occur due to postpartum hemorrhage.

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<![CDATA[Establishment of an analysis model based on measurement of hepatitis B viral infection serum markers]]> https://www.researchpad.co/article/5c8bfa07d5eed0c484b21e16

Background

Using serum markers of hepatitis B virus (HBV) infection, we aimed to develop a quantitative model that explains the complicated immune response to this infection.

Methods

Serum samples from HBV-infected patients were randomly selected and divided into groups based on HBV-DNA positivity or negativity. Quantitative markers of HBV were measured. Formulae for Antibody index (IAb) [(anti-HBs * 1/anti-HBe + anti-HBs * 1/anti-HBc + 1/anti-HBc * 1/anti-HBe)0.5] and Antigen index (IAg) [(HBsAg * HBeAg)0.5] were introduced.

Results

IAg values were statistically higher (p < 0.05) in the HBV-DNA-positive group than in the -negative group, but no statistically significant difference in IAb values was observed. When IAb values were > 50, IAg values were mostly < 250; when IAg values were > 250, IAb values were mostly < 50.

Conclusion

IAb and IAg values can efficiently reflect the status of immune response to HBV and may be suitable for assessment of the infection process and the possible outcome of infection.

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<![CDATA[Identification of biomarkers for amyotrophic lateral sclerosis by comprehensive analysis of exosomal mRNAs in human cerebrospinal fluid]]> https://www.researchpad.co/article/5c48fc1dd5eed0c4841fd8f5

Background

Exosomes are a subset of extracellular vesicles 30–200 nm in diameter secreted from cells, which contain functional mRNAs and microRNAs. Cerebrospinal fluid (CSF) is the primary source for liquid biopsy to examine diseases in central nervous system. To date, there is no available method to analyze exosomal mRNAs comprehensively in human CSF.

Methods

The main purpose of this study is to established the methodology of comprehensive analysis of exosomal mRNAs in CSF by a highly sensitive next-generation sequencing. The signatures of CSF exosomal mRNAs were then compared between four normal healthy donors and four sporadic amyotrophic lateral sclerosis patients to identify disease-related biomarkers. Differentially expressed genes were identified by DESeq2.

Results

RNA sequencing from CSF exosomes was successfully performed, that was demonstrated by the high pearson’s product-moment correlation coefficient (r = 0.993) in the technical replicates. Also, position coverage analysis revealed that most detected mRNAs retained their integrity throughout their full-length in CSF exosomes. In CSF exosomes from normal healthy donors, an average of 14,807 genes were detected, of which 4580 genes were commonly detected among four individuals, including neuron-enriched genes such as TUBB3 and CAMK2A. In comparison with exosomal mRNAs in CSF from four patients with amyotrophic lateral sclerosis, 543 genes were significantly changed, as represented by CUEDC2. Gene Ontology analysis and pathway analysis with these genes revealed functional enrichment of ubiquitin-proteasome pathway, oxidative stress response, and unfolded protein response. These pathways are related to pathomechanisms of amyotrophic lateral sclerosis.

Conclusion

We successfully established the methodology of comprehensive analysis of exosomal mRNAs in human CSF. It was shown to be useful to identify disease biomarkers for central nervous system. Several genes, such as CUEDC2, in CSF exosomes were suggested to be candidate disease biomarkers for amyotrophic lateral sclerosis.

Electronic supplementary material

The online version of this article (10.1186/s12920-019-0473-z) contains supplementary material, which is available to authorized users.

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<![CDATA[A new approach for sample size calculation in cost-effectiveness studies based on value of information]]> https://www.researchpad.co/article/5c116138d5eed0c484638b4d

Background

Value of information is now recognized as a reference method in the decision process underpinning cost-effectiveness evaluation. The expected value of perfect information (EVPI) is the expected value from completely reducing the uncertainty surrounding the cost-effectiveness of an innovative intervention.

Among sample size calculation methods used in cost-effectiveness studies, only one is coherent with this decision framework. It uses a Bayesian approach and requires data of a pre-existing cost-effectiveness study to derive a valid prior EVPI. When evaluating the cost-effectiveness of innovations, no observed prior EVPI is usually available to calculate the sample size.

We here propose a sample size calculation method for cost-effectiveness studies, that follows the value of information theory, and, being frequentist, can be based on assumptions if no observed prior EVPI is available.

Methods

The general principle of our method is to define the sampling distribution of the incremental net monetary benefit (ΔB), or the distribution of ΔB that would be observed in a planned cost-effectiveness study of size n. Based on this sampling distribution, the EVPI that would remain at the end of the trial (EVPIn) is estimated. The optimal sample size of the planned cost-effectiveness study is the n for which the cost of including an additional participant becomes equal or higher than the value of the information gathered through this inclusion.

Results

Our method is illustrated through four examples. The first one is used to present the method in depth and describe how the sample size may vary according to the parameters’ value. The three other examples are used to illustrate in different situations how the sample size may vary according to the ceiling cost-effectiveness ratio, and how it compares with a test statistic-based method. We developed an R package (EBASS) to run these calculations.

Conclusions

Our sample size calculation method follows the value of information theory that is now recommended for analyzing and interpreting cost-effectiveness data, and sets the size of a study that balances its cost and the value of its information.

Electronic supplementary material

The online version of this article (10.1186/s12874-018-0571-1) contains supplementary material, which is available to authorized users.

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