F1000Research最新文献

Background: Excess nitrogen (N) loading to coastal ecosystems impairs estuarine water quality. Land management decisions made within estuarine watersheds have a direct impact on downstream N delivery. Natural features within watersheds can act as landscape sinks for N, such as wetlands, streams and ponds that transform dissolved N into gaseous N, effectively removing it from the aquatic system. Identifying and evaluating these landscape sinks and their spatial relationship to N sources can help managers understand the effects of alternative decisions on downstream resources.

Methods: The N-Sink approach uses widely available GIS data to identify landscape sinks within HUC-12 (or larger) catchments, estimate their N removal potential and map the effect of those sinks on N movement through the catchment. Static maps are produced to visualize N removal efficiency, transport and delivery, the latter in the form of an index. The R package nsink was developed to facilitate data acquisition, processing and visualization.

Results: nsink creates static maps for a specific HUC-12, or users can visit the University of Connecticut website to explore previously mapped areas. Users can investigate specific flowpaths interactively by clicking on any location within the catchment. A flowpath is generated with a table describing N removal along each segment. We describe the motivation behind developing nsink, discuss implementation in R, and present two use case examples. nsink is available from https://github.com/USEPA/nsink.

Conclusions: N-Sink is a decision support tool created for local decision-makers and NGOs to facilitate better understanding of the relationship between land use and downstream N delivery. Local decision-makers that have prioritized N mitigation in their long-term planning can use nsink to better understand the potential impact of proposed development projects, zoning variances, and land acquisition or restoration. nsink also allows resource economists to investigate the tradeoffs among different, often costly, N reduction strategies.

Background: Aortoiliac occlusive disease (AIOD) or Leriche syndrome, is a form of peripheral arterial disease involving the infrarenal aorta and iliac arteries. The presentation of AIOD ranges from asymptomatic cases to limb-threatening emergencies. Advances and innovations in endovascular devices have replaced traditional surgical interventions for the management of AIOD. Here we report a case of a 52-year-old man presenting with AIOD managed by endovascular approach using kissing stent technique.

Case presentation: A 52-year-old man, with history of chronic coronary artery disease, diabetes mellitus type 2, long-standing hypertension, and a significant history of smoking, was admitted to our hospital with symptoms of long-standing bilateral claudication which recently progressed to rest pain. A history of AIOD was previously established. AIOD (TASC II Type D) diagnosis was made by lower extremity duplex ultrasound and CT angiography. The patient underwent urgent percutaneous transluminal angioplasty with kissing stent technique. The patient was discharged 4 days after the procedure without any significant complaints, received best medical therapy.

Conclusion: Endovascular interventions present excellent alternatives to surgical techniques in the treatment of complex AIOD. Herein we presented an endovascular treatment of AIOD utilizing the kissing stent technique which showed satisfactory outcomes.

Background: Endovascular repair for abdominal aortic aneurysms (AAA) has been the gold standard since it was established in 1991. Various graft configurations have been developed to overcome the limitations of endovascular aortic repair (EVAR), including contralateral gate cannulation (CGC). We propose a new device and technique intended to simplify endovascular AAA repair, along with reports of its application in six patients.

Intervention: The Taofan and Kang (T&K) bidirectional endovascular aortic repair (B-EVAR (B-EVAR) device uses a main-body stent graft, two-limb extensions, and bare metal stent. The procedure involved accessing the right and left femoral arteries, followed by standard aortography evaluation using a pigtail catheter through the contralateral femoral access. The main body stent graft is deployed through ipsilateral femoral access using a balloon catheter, while the contralateral gate is cannulated with a hydrophilic coated wire. Both balloons were inflated simultaneously to ensure that the wires were in different lumens. Contralateral and ipsilateral extensions were deployed using a limb extension stent graft. Standard aortography evaluation was repeated.

Result: T&K B-EVAR pilot procedures proved successful in various cases, from simple to complex anatomy, and even with varied graft stent deployment strategies. None of the patients had complications or prolonged length of stay (LOS). Follow-up CT did not reveal any high-pressure endoleaks.

Conclusion: T&K B-EVAR has been proven to simplify endovascular AAA repair in six patients with excellent results. It is also reproducible, potentially universally applicable, and can offer operators ease of use, faster procedure times, reduced fluoroscopy times, and reduced contrast usage.

Background: The association between anemia and severity of infection as well as mortality rates among patients infected with COVID-19 has scarcely been studied. This is the first study from the UAE aimed to assess the influence of anemia on COVID-19 severity, ICU admission, and mortality rate.

Methods: A retrospective chart review of hospitalized COVID-19 patients was conducted in a large COVID-19 referral hospital in UAE. The study included adult patients with confirmed COVID-19. Clinical and laboratory data, severity of the disease, ICU admissions, and mortality rates were analyzed and correlated to the presence of anemia among the patients.

Results: A total of 3092 patients were included. 362 patients (11.7%) were anemic and most of the cases were between asymptomatic and mild COVID-19 (77.4%, n=2393). Among patients with anemia, 30.1% (n=109) had moderate to severe COVID-19. Statistically, anemia was associated significantly with a higher risk for severe COVID-19 outcome compared to nonanemic patients (AOR:1.59, 95% CI:1.24-2.04, p<0.001). Intensive care unit (ICU) admission was almost 3 times higher among anemic patients compared to nonanemic (AOR:2.83,95% CI:1.89-4.25, p<0.001). In addition, the overall mortality rate of 2.8% (n=87) was 2.5-fold higher in anemic than nonanemic patients (OR:2.56, CI: 1.49-4.06, p<0.001). Moreover, older age (≥48-year-old) and male gender were independent predictors for severe illness (Age: OR=1.26, CI:1.07-1.51, p=0.006; Gender: OR:1.43,CI:1.15-1.78, p<0.001)) and ICU admission (Age: OR:2.08, CI:1.47-2.94, p<0.001; Gender: OR: 1.83, CI:1.12-3.00, p=0.008) whereas only age ≥48 years old contributed to higher mortality rate (OR:1.60, CI:1.04-2.46, p=0.034).

Conclusion: Anemia was a major risk factor for severe COVID-19, ICU admission and mortality among hospitalized COVID-19 patients. Thus, healthcare providers should be aware of monitoring the hematological parameters among hospitalized patients with COVID-19 and anemia to reduce the risk of disease complications and mortality. This association should also be considered in other infectious diseases.

Background: Preprints are scientific manuscripts that are made available on open-access servers but are not yet peer-reviewed. Although preprints are becoming more prevalent, uptake is not optimal. Understanding researchers' opinions and attitudes toward preprints is valuable to optimize their use. Understanding knowledge gaps and researchers' attitudes toward preprinting can assist stakeholders, such as journals, funding agencies, and universities, to use preprints more effectively. Here, we aimed to collect perceptions and behaviours regarding preprints across an international sample of biomedical researchers.

Methods: Corresponding authors of articles published in biomedical research journals were identified from a random sample of journals from the MEDLINE database. Their names and email addresses were extracted to invite them to our anonymous, cross-sectional survey, which asked participants questions about their knowledge, attitudes, and opinions regarding preprinting.

Results: The survey was completed by 730 respondents providing a response rate of 3.20% and demonstrated a wide range of attitudes and opinions about preprints with authors from various disciplines and career stages worldwide. Most respondents were familiar with the concept of preprints but most had not previously posted one. The lead author of the project and journal policy had the greatest impact on decisions to post a preprint, whereas employers/research institutes had the least impact. Supporting open science practices was the highest ranked incentive, while increasing authors' visibility was the highest ranked motivation for publishing preprints.

Conclusions: Although many biomedical researchers recognize the benefits of preprints, there is still hesitation among others to engage in this practice. This may be due to the general lack of peer review of preprints and little enthusiasm from external organizations such as journals, funding agencies, and universities. Future work is needed to determine optimal ways to improve researchers' attitudes through modifications to current preprint systems and policies.

Background: The response of heart rate to changes in exercise intensity is comprised of several dynamic modes with differing magnitudes and temporal characteristics. Investigations of empirical identification of dynamic models of heart rate showed that second-order models gave substantially and significantly better model fidelity compared to the first order case. In the present work, we aimed to reanalyse data from previous studies to more closely consider the effect of including a zero and a pure delay in the model.

Methods: This is a retrospective analysis of 22 treadmill (TM) and 54 cycle ergometer (CE) data sets from a total of 38 healthy participants. A linear, time-invariant plant model structure with up to two poles, a zero and a dead time is considered. Empirical estimation of the free parameters was performed using least-squares optimisation. The primary outcome measure is model fit, which is a normalised root-mean-square model error.

Results: A model comprising parallel connection of two first-order transfer functions, one with a dead time and one without, was found to give the highest fit (56.7 % for TM, 54.3 % for CE), whereby the non-delayed component appeared to merely capture initial transients in the data and the part with dead time likely represented the true dynamic response of heart rate to the excitation. In comparison, a simple first-order model without dead time gave substantially lower fit than the parallel model (50.2 % for TM, 47.9 % for CE).

Conclusions: This preliminary analysis points to a linear first-order system with dead time as being an appropriate model for heart rate response to exercise using treadmill and cycle ergometer modalities. In order to avoid biased estimates, it is vitally important that, prior to parameter estimation and validation, careful attention is paid to data preprocessing in order to eliminate transients and trends.

Background: During pregnancy, the placenta is an extremely important organ as it secretes its own hormones, e.g. insulin-like growth factor 1 (IGF-1), to ensure proper intrauterine fetal growth and development. Ethanol, an addictive and widely used drug, has numerous adverse effects during pregnancy, including fetal growth restriction (FGR). To date, the molecular mechanisms by which ethanol triggers its toxic effects during pregnancy, particularly in the placenta, are not entirely known. For this reason, a murine model of partial IGF-1 deficiency was used to determine ethanol alterations in placental morphology and aspartyl/asparaginyl β-hydroxylase (AAH) expression.

Methods: Wild type (WT, Igf1 ^+/+) and heterozygous (HZ, Igf1 ^+/-) female mice were given 10% ethanol in water during 14 days as an acclimation period and throughout pregnancy. WT and HZ female mice given water were used as controls. At gestational day 19, pregnant dams were sacrificed, placentas were collected and genotyped for subsequent studies.

Results: IGF-1 deficiency and ethanol consumption during pregnancy altered placental morphology, and decreased placental efficiency and AAH expression in placentas from all genotypes. No differences were found in Igf1, Igf2, Igf1r and Igf2r mRNA expression in placentas from all groups.

Conclusions: IGF-1 deficiency and ethanol consumption throughout gestation altered placental development, suggesting the crucial role of IGF-1 in the establishment of an adequate intrauterine environment that allows fetal growth. However, more studies are needed to study the precise mechanism to stablish the relation between both insults.

Background: The EMPIRE (EMpirical Publication Impact and Reach Evaluation) Index is a value-based, multi-component metric framework to assess the impact of medical publications in terms of relevance to different stakeholders. It comprises three component scores (social, scholarly and societal impact), each incorporating related altmetrics that indicate a different aspect of engagement with the publication. Here, we present an exploratory investigation of whether publication types or disease indications influence EMPIRE Index scores.

Methods: Article-level metrics were extracted and EMPIRE Index scores were calculated for 5825 journal articles published from 1 May 2017 to 1 May 2018, representing 12 disease indications (chosen to reflect a wide variety of common and rare diseases with a variety of aetiologies) and five publication types.

Results: There were significant differences in scores between article types and disease indications. Median (95% CI) social and scholarly impact scores ranged from 1.2 (0.3-1.6) to 4.8 (3.1-6.6), respectively, for phase 3 clinical trials, and from 0.3 (0.3-0.4) to 2.3 (1.9-2.6), respectively, for observational studies. Social and scholarly impact scores were highest for multiple sclerosis publications and lowest for non-small cell lung cancer publications. Systematic reviews achieved greater impact than regular reviews. Median trends in the social impact of different disease areas matched the level of public interest as assessed through Google search interest. Although most articles did not register societal impact, mean societal impact scores were highest for migraine publications.

Conclusions: The EMPIRE Index successfully identified differences in impact by disease area and publication type, which supports the notion that the impact of each publication needs to be evaluated in the context of these factors, and potentially others. These findings should be considered when using the EMPIRE Index to assess publication impact.

Background: Auditors during COVID-19 experienced an unprecedented situation, in which normal audit activities were difficult to conduct. Moreover, COVID-19 forced auditors to introduce a new audit approach, "remote auditing," which was not common in most audit firms and required the adoption of more advanced technologies. Overall, auditors during the COVID-19 pandemic needed both cognitive and technical factors to deliver high-quality audits. Despite these challenges, research on how auditors deal with these issues is limited, presenting an intriguing area of study.

Methods: This dataset provides insights into Saudi auditors' experience and beliefs regarding audit activities during COVID-19. Through an online survey, researchers collected data from 193 of 417 registered auditors with the Saudi Organization for Chartered and Professional Accountants (SOCPA). The survey assessed auditors' self-efficacy in conducting audits during the pandemic and explored its sources and potential moderating factors. Specifically, the dataset includes responses to eight items related to self-efficacy, 19 items covering four common sources of self-efficacy (mastery experience, vicarious experience, social persuasion, and physiological/emotional states), and six items assessing virtual audit competency. Additionally, the dataset contains demographic information that is valuable for researchers analyzing the relationship between auditor self-efficacy, its sources, and other influencing factors.

Conclusions: Overall, the dataset included in this study may serve a broader audience and be useful in improving several stakeholders' understanding of the effects of COVID-19 on auditors and how auditors assess their ability to adapt to COVID-19 consequences. This study contributes to the existing body of knowledge by highlighting the need for auditors to adapt to new circumstances and adopt innovative approaches during challenging times, thereby ensuring the delivery of high-quality audits.

The utilization of zein and gum arabic has grown in an attempt to formulate wall materials based on protein-polysaccharide complexes. This mixture provides a versatile delivery system for hydrophilic (guava leaf extract, GLE) or lipophilic (fish oil, FO) bioactive compounds, and it can be used as an edible film-forming polymer. This study was undertaken to characterize FO-containing edible films that were double-layered with a film containing GLE. Modified zein and gum arabic solutions (MG complex) were mixed at a ratio of 1:1.5 (v/v), adjusted to pH 5, added with glycerol (20% of the complex) and FO (5% of the complex), and finally adjusted to pH 5. This was prepared as the bottom/lower layer. The upper/active layer was prepared by mixing MG complex, glycerol, and GLE (1, 3, and 5% w/v of the complex). The total phenolic and flavonoid contents in GLE were 15.81 mg GAE/g extract and 6.99 mg QE/g extract, respectively. The IC50 of the DPPH radical scavenging activity of GLE was 26.86 ppm with antibacterial activity against Bacillus subtilis and Escherichia coli of 9.83 and 12.55 mm. The total plate counts of double-layered films containing GLE were retained below 3 log CFU/g during 28-day storage. The peroxide values of these films were dimmed for no more than 9.08 meq/kg sample on day 28 of storage. Thickness (872.00-971.67 μm), water vapor transmission rate (12.99-17.04 g/m ²/day), tensile strength (1.56-2.02 kPa), elongation at break (61.53-75.41%), glass transition (52.74-57.50°C), melting peak (131.59-142.35°C), inhibition against B. subtilis (33.67-40.58 mm), and inhibition against E. coli (2.05-9.04 mm) were obtained by double-layered films. GLE can be successfully incorporated into the active layer of a double-layer film to improve its characteristics while significantly slowing down the microbial contamination and oxidation rate. MG complex and FO can also contribute to the performance of the edible film.