Discover and publish cutting edge, open research.

Browse 13,794 multi-disciplinary research preprints

Most recent

Travis Geraci

and 10 more

Anaïs Lemoine

and 5 more

Background Food protein-induced enterocolitis syndrome (FPIES) is a non IgE-mediated food allergy, with potential dehydration secondary to vomiting. Differences exist regarding culprit foods, onset symptoms, and age of tolerance depending on the country of origin. We aimed to describe the characteristics of a French population of children with FPIES. Methods Data from 179 children who were referred for acute or chronic FPIES in two pediatric tertiary centers between 2014 and 2020 were retrospectively collected. The diagnosis of FPIES was based on international consensus guidelines. Clinical characteristics, culprit food and age at resolution were assessed. Results In the 192 described FPIES, the age at first symptoms was 5.8 months old. The main offending foods were cow’s milk (60.3%), hen’s egg (16.2%), and fish (11.7%). Single FPIES was observed in 94.4% and multiple FPIES in 5.6% of cases. The age at resolution of FPIES was 2.2 years old, and resolution occurred later for fish than for milk (2.9 years versus 2.0, p=0.01). Severe acute FPIES was a risk factor for delayed resolution (relative risk: 3.3 [1.2-9.2]), but not IgE sensitization. Performing an oral food challenge within 12 months after the first reaction increased the risk of failure (RR: 2.0 [1.2-3.5]). Conclusion In this French cohort of children with FPIES, the main culprit foods were ubiquitous. Rice, oat and soy were rarely or not involved. Multiple FPIES was infrequent. Our data confirmed the overall good prognosis of FPIES, the later resolution of FPIES to fish and in the case of severe acute FPIES.

zhu xuefeng

and 10 more

Aims: This study sought to describe originating from the spontaneous scarring of left atrial anterior wall (LAAW) left atrial macroreentry tachycardia (LAMRT) clinical and electrophysiological characteristics, mechanisms, the formation of substrates. Methods and Results: 9 of 123 patients (89% female, age 79.78±5.59 years) had LAMRT originating from the LAAW and no cardiac surgery or prior left atrial (LA) ablation. The mean tachycardia cycle length (TCL) was 241.67±38.00 milliseconds. Spontaneous scars areas and low voltage areas (LVAs) in the LAAW were found in all patients. Successful ablation of the critical isthmus caused terminated of the LAMRT and was not inducible in all patients. Arrhythmogenic substrates of LAMRT were the spontaneous scars of LAAW, which matched with the aorta or/and pulmonary artery contact area. The area under the curve (AUC) of age and combination of gender and age for predicting the LAMRT originating from the LAAW were 0.918 and 0.951, respectively, with a cutoff value of ≥73.5 years of age and gender (female) predicting LAMRT with 88.9% sensitivity and 89% specificity. Conclusion: Combination of gender and age provides a simple and useful criterion to distinguish LAMRT from cavo-tricuspid isthmus (CTI) -dependent atrial tachycardia in macroreentry atrial tachycardia (MRAT) in patients without a history of surgery or ablation. Aorta or/and pulmonary artery contacting LA may be related to spontaneous scars. Ablation the isthmus eliminated LAMRT in all patients.

Steven Ferguson

and 5 more

Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species’ geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to reproductive activity (RA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts. Based on the previous finding of reproductive senescence in older HB females, but not for BB whales, we compared RA patterns the of the two populations’ with age and body length. Female beluga whale RA increased more quickly with age (63% partial variation explained) in BB than in HB (41%). In contrast, body length in HB female beluga whale accounted for considerably more of the total variation (12 vs 1%) in RA compared to BB whales. We speculate that female HB beluga whale RA was more strongly linked with body length due to higher population density resulting in food competition that favors the energetic advantages of larger body size during seasonal food limitations. Understanding the evolutionary mechanism of how RA, and potentially fitness, varies across a species’ range will assist conservation efforts in anticipating and mitigating future challenges associated with a warming planet.

Bora Tetik

and 7 more

Background: The known primary radiological diagnosis of Chiari Malformation-I (CM-I) is based on the degree of tonsillar herniation ( TH) below the Foramen Magnum (FM). However, recent data also shows the association of such malformation with smaller posterior cranial fossa (PCF) volume and the anatomical issues regarding the Odontoid. This study presents the achieved result regarding some detected potential radiological findings that may aid CM-I diagnosis using several machine learning (ML) algorithms. Materials and Methods: Between 2011 and 2020, radiological examinations of 100 clinically/radiologically proved symptomatic CM-I cases and 100 control were evaluated by matching age and gender. A team of Neuroradiologists had reviewed the MR images of the study population. A total of 11 different radiological parameters were assessed for CM-I diagnosis. The parameters were defined and examined in 5 designed different ML algorithms. Statistical analysis was conducted for data analysis. Results: The mean age of patients was 29.92 ± 15.03 years. The primary presenting symptoms were headaches (62%). Syringomyelia and retrocurved-odontoid were detected in 34% and 8% of patients, respectively. All of the morphometric measures were significantly different between the groups, except for the distance from the dens axis to the posterior margin of FM. The Radom Forest model is found to have the best 1.0 (14 of 14) ratio of accuracy in regard to 14 different combinations of morphometric features. Conclusion: This study indicates the potential usefulness of ML-guided PCF measurements, other than TH, that may be used to predict and diagnose CM-I accurately. Our results support the view of TH as a single radiological parameter may fail during the diagnosis of CM-I. Combining two or three preferable osseous structure-based parameters may increase the accuracy of radiological diagnosis of CM-I.

Jason Cook

and 1 more

Leadless Pacing with Mechanical Atrial Sensing and Variable AV ConductionJason Cook, MDTravis D. Richardson, MDFrom Vanderbilt University Medical Center. Nashville, TennesseeCorresponding author:Travis D. Richardson, MDAssistant Professor Cardiac ElectrophysiologyVanderbilt Heart and Vascular Institute1215 21st Ave S. Nashville, TNMedical Center East, South Tower, Suite 5209ph (615) 936-7537fax (615) 936-5064travis.d.richardson@vanderbilt.eduWord Count:1331Disclosures: The authors report no relevant financial disclosures.Funding: NoneThe MicraTM leadless transcatheter pacing system (Medtronic Inc., Mounds View, MN) has been shown to be an effective alternative to transvenous pacing with excellent implantation success rates and durable long-term performance.1–3 The first generation device provided single chamber right ventricular pacing with rate responsiveness enabled by a 3-axis accelerometer.Recently, the MARVEL 2 study (Micra Atrial tRacking using a Ventricular accELerometer 2) reported the ability of software enhancements to allow a leadless pacemaker to deliver single chamber atrioventricular (AV) synchronized pacing.4 In contrast to dual-chamber transvenous pacemakers which sense atrial electrograms, the MARVEL 2 algorithm adjudicates atrial events using mechanically sensed atrial activity from the 3-axis accelerometer. During initial programming, the relative timing of mechanical events to the ventricular electrogram allows for identification of A3 (passive ventricular filling) and A4 (atrial contraction). Atrial-sensed events are then defined by the A4 signal, and tracking may occur. MARVEL 2 reported VDD pacing was achieved at rest in an impressive 89.2% of patients.The Micra AVTM system’s unique programming includes three basic pacing modes: VDD, VVI and VDIR (Figure 1). Additionally, two mode switch algorithms are available and by default programmed on: the AV conduction mode switch and the activity mode switch. Unlike mode switch algorithms in dual chamber pacing systems, which are intended to avoid inappropriate tracking of atrial arrhythmias, these algorithms are intended to 1) minimize ventricular pacing, and 2) to improve rate support during patient activity respectively.When the AV conduction mode switch algorithm is enabled, the device periodically switches from VDD to VVI at 40 bpm to allow for intrinsic AV conduction. If ventricular sensing occurs above a rate of 40 bpm, in order to reduce right ventricular pacing, VVI 40 programming will continue regardless of the programmed lower rate limit. However, if two of any window of four beats are paced at VVI 40, the device reverts to VDD. Thereafter, reassessments of AV conduction are performed at increasing intervals starting at 2 minutes until either AV conduction is detected or 8 hours is reached at which point subsequent testing occurs at regular 8 hour intervals.The activity mode switch algorithm utilizes the sensor indicated rate in an attempt to ensure adequate ventricular rate support during patient activity regardless of AV conduction. The sensor in the MicraTM is always running. If at any time 1) the sensor indicated rate is above the device programmed ADL rate, and 2) the current ventricular rate is >20 BPM below the sensor rate, the activity mode switch will change the device to VDIR mode with heart rates determined by the sensor. This switch may occur from either the VDD mode or VVI in the setting of AV conduction. The device will revert to VDD mode when the sensor rate drops below the ADL rate.With the added functionality of atrial sensing and the incorporation of the MARVEL 2 algorithms described above, in this issue of the Journal of Cardiovascular Electrophysiology, Garweg et al. examined the pacing behavior of the Micra AVTM in the presence of variable AV conduction, atrial arrhythmias, sinus bradycardia (< 40 bpm), sinus arrhythmia, and periods of atrial and ventricular ectopy (Reference). During the data collection period in MARVEL 2, ECG, electrogram, accelerometer waveforms, and device marker data were obtained; this was collected either after initial implant and follow-up or, for patients with previously placed devices, during a single encounter. The average monitoring period was 153 minutes. The study included 73 patients with normal sinus node function and varying degrees of AV block.While the number of patients with variable AV conduction was small (5), the investigators found that the rhythm checks allowed for appropriate mode adjustments during the study period. During periods of AV block, as expected, 99.9% ventricular pacing was observed while during 1:1 AV conduction only 0.2% pacing was observed. Ventricular pacing was monitored in patients with 1:1 AV conduction using conventional VVI pacing and MARVEL 2 programming. MARVEL 2 programming using the AV conduction mode switch algorithm resulted in a reduction in ventricular pacing from 22.8% to 0.2% (n=18). Reducing the burden of ventricular pacing is an important enhancement to the system with the potential to minimize pacing-induced cardiomyopathy.5One potential pitfall of atrial sensing addressed by this study is tracking of atrial arrhythmias. While the sample size was small (n=7), tracking of atrial fibrillation resulting in pacing at the upper tracking rate was not observed in any of the patients. In one patient with atrial flutter, intermittent atrial tracking did occur but did not result in tachycardia. In contrast to atrial rate based mode switching used in conventional dual-chamber pacemakers, the behavior of the MARVEL 2 algorithm during atrial fibrillation is dictated by the sensed ventricular rate. With the AV conduction mode switch enabled, if the ventricular rate is above 40 bpm, the pacing mode will be VVI at 40 bpm. If rates are less than 40 bpm, the pacing mode will be VDD. In the context of atrial fibrillation, reduced atrial contractility results in lack of mechanical sensing, and pacing at the lower rate is observed. In this small sample size, atrial arrhythmias did not result in device tracking resulting in tachycardia. Further investigation in a larger number of patients is warranted to better characterize these findings and to assess pacing behavior during more organized atrial arrhythmias which could result in mechanical sensing (atrial tachycardia and atrial flutter, for example).While the MARVEL 2 programming seems to perform well in the setting of atrial fibrillation or intermittent complete AV block, there are some potential pitfalls. AV conduction mode switch behavior is based on sensed ventricular rates with a threshold of 40 bpm; this cutoff is not currently programmable. Any ventricular sensed rhythm with a rate greater than 40 bpm will result in the device continuing at VVI 40. For example, in a patient with sinus rhythm at 90 bpm and 2:1 AV conduction, the device would not track the atrium and pace at 90 bpm, but rather remain VVI 40 because the ventricular sensed rate is above 40 bpm. The same would be observed in patients with junctional or ventricular escape rhythms >40 bpm. In this sense, pacing could be inappropriately inhibited during a potentially hemodynamically significant rhythm. For this reason, in our opinion, the AV conduction mode switch algorithm should be disabled in the majority of patients with AV block as this physiology is dynamic and sudden loss of rate support can have deleterious consequences. While the activity mode switch algorithm may address some of these concerns real world data are needed for validation.There is no question that the functionality and indications for leadless pacemakers will continue to expand. In current guidelines, which predate the development of the Micra AVTM, single chamber ventricular pacing is only recommended in patients with AV block and permanent atrial fibrillation, a low burden of anticipated pacing, or substantial comorbidities.6 Given the potential for lower complication rates compared with transvenous systems, Micra AV may be a superior option in some patients with complete heart block and preserved ventricular function. However, with the advent of conduction system pacing, the decreased risks of a leadless system have to be balanced with the relative risk of long term right ventricular pacing. Although the results will need to be validated with larger, longer-term studies, which are underway (Clinical NCT04245345), these data indicate that Micra AVTM is likely to perform well in the setting of atrial arrhythmias. In patients with variable AV conduction, there are certainly pitfalls to the AV conduction mode switch algorithm, many of which could be avoided by the ability to program the mode switch VVI rate. While leadless pacing is often considered in patients with multiple comorbidities at high risk of complications from a transvenous system, we may be on the cusp of a dramatic paradigm shift. The technological developments and success of leadless pacing to date prompt the question of when, and not if, leadless dual chamber pacing and potentially even cardiac resynchronization will be available.References:1. Reynolds D, Duray GZ, Omar R, et al. A Leadless Intracardiac Transcatheter Pacing System. doi:10.1056/NEJMoa15116432. El-Chami MF, Al-Samadi F, Clementy N, et al. Updated performance of the Micra transcatheter pacemaker in the real-world setting: A comparison to the investigational study and a transvenous historical control. Heart Rhythm . 2018;15(12):1800-1807. doi:10.1016/j.hrthm.2018.08.0053. Duray GZ, Ritter P, El-Chami M, et al. Long-term performance of a transcatheter pacing system: 12-Month results from the Micra Transcatheter Pacing Study. Heart Rhythm . 2017;14(5):702-709. doi:10.1016/j.hrthm.2017.01.0354. Steinwender C, Khelae SK, Garweg C, et al. Atrioventricular Synchronous Pacing Using a Leadless Ventricular Pacemaker: Results From the MARVEL 2 Study. JACC Clin Electrophysiol . 2020;6(1):94-106. doi:10.1016/j.jacep.2019.10.0175. Merchant FM, Mittal S. Pacing induced cardiomyopathy. J Cardiovasc Electrophysiol . 2020;31(1):286-292. doi:10.1111/jce.142776. Kusumoto Fred M., Schoenfeld Mark H., Barrett Coletta, et al. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation . 2019;140(8):e382-e482. doi:10.1161/CIR.0000000000000628

Marian Boshra

and 3 more

Objectives: The treatment of COVID-19 infection remains a challenge because till now, there is no approved therapy for it. This study aimed to estimate the difference in the therapeutic efficacy and safety between remdesivir as monotherapy and its use in combination with lopinavir/ritonavir provided with standard supportive care. Methods: This is a prospective randomized cohort study included 1043 adult patients with confirmed moderate and severe COVID-19 infection. Treatment of all patients followed Egyptian Ministry of Health COVID-19 protocol as the first group received IV remdesivir 200 mg on day 1, followed by 100 mg once daily, for 5 days while the second group received lopinavir/ritonavir 400/100 mg twice daily, for 5 days with the same remdesivir regimen in the first group. All laboratory and clinical parameters were assessed before and after treatment duration. Results: There was no significant difference related to improvement parameters such as laboratory data and improvement time between the two groups. On the other hand, hepatotoxicity of the second group (combination) was significantly higher compared with that of the first one. The elevation on liver enzymes was affected by the severity of the disease, the severe cases showed a high enzyme elevation rate. Conclusion: Remdesivir as monotherapy and its use in combination with lopinavir/ritonavir is effective in the management of moderate COVID 19 subjects than severe cases. The combination of remdesivir with lopinavir/ritonavir is not recommended due to the increased hepatotoxicity effect.

Vicenç Carabassa

and 15 more

In the light of the current climate crisis, one of the most serious ecological threats is the increase of desertification. In this context, restoration projects are necessary for reverting land degradation, and nature-based solutions could help them. The Cocoon™ has been designed as a new ecotechnology for improving seedling establishment. The Cocoon consists of a donut-shaped container made out of recycled cardboard that provides water and shelter to the seedling, at least during its first year, which is the most critical for plant establishment. The Cocoon was tested on a variety of soils, Mediterranean mesoclimates, vegetation and land uses that allowed testing the effectiveness of this ecotechnology under different conditions. Six planting trials, five of them in Spain (Canary Islands, Almería, Catalonia and two in Valencia), and one in Ptolemais (Greece), were performed. With the objective of studying its functionality, the survival of the seedlings, their vigor and growth were monitored along two years. In general, the Cocoon has proven its effectiveness by increasing seedling survival compared to the conventional planting system, especially under dry growing conditions (low rainfall, soils with low water holding capacity). The Cocoon also allowed for higher growth of some species (olive trees, olm oaks and Aleppo pines). Moreover, a positive correlation between the rainfall on the site and the degradation degree of the Cocoon device was observed. Overall, the Cocoon becomes more efficient the more arid the climate or the more difficult the growing conditions are.

Browse more recent preprints

Recently published in scholarly journals

Mohammed Al-Sadawi

and 7 more

Abstract: Background: This meta-analysis assessed the relationship between Obstructive Sleep Apnea (OSA) and echocardiographic parameters of diastolic dysfunction (DD), which are used in the assessment of Heart Failure with Preserved Ejection Fraction (HFpEF). Methods: We searched the databases including Ovid MEDLINE, Ovid Embase Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 26th, 2020. The search was not restricted to time, publication status or language. Comparisons were made between patients with OSA, diagnosed in-laboratory polysomnography (PSG) or home sleep apnea testing (HSAT), and patients without OSA in relation to established markers of diastolic dysfunction. Results: Primary search identified 2512 studies. A total of 18 studies including 2509 participants were included. The two groups were free of conventional cardiovascular risk factors. Significant structural changes were observed between the two groups. Patients with OSA exhibited greater LAVI (3.94 CI [0.8, 7.07]; p=0.000) and left ventricular mass index (11.10 CI [2.56,19.65]; p=0.000) as compared to control group. The presence of OSA was also associated with more prolonged DT (10.44 ms CI [0.71,20.16]; p=0.04), IVRT (7.85 ms CI[4.48, 11.22]; p=0.000), and lower E/A ratio (-0.62 CI [-1,-0.24]; p=0.001) suggestive of early DD. The E/e’ ratio (0.94 CI[0.44, 1.45]; p=0.000) was increased. Conclusion: An association between OSA and echocardiographic parameters of DD was detected that was independent of conventional cardiovascular risk factors. OSA may be independently associated with DD perhaps due to higher LV mass. Investigating the role of CPAP therapy in reversing or ameliorating diastolic dysfunction is recommended.

Huseyin Kazan

and 6 more

Objective: To investigate the factors, especially preoperative urinalysis, predicting postoperative early infection after retrograde intrarenal surgery (RIRS) in 1-2 cm renal stones. Methods: Of the 642 patients who underwent RIRS between September 2013 and July 2019, 289 patients with a total stone size of 1-2 cm were included in the study. Patients were divided into two groups as with and without postoperative urinary tract infection. The demographic data and perioperative findings of all patients were retrospectively reviewed. Sterile urine cultures were obtained in all patients during the preoperative 30-day period and urine analysis values were included in the data. Results: Urinary system infection (UTI) was seen in 20 (6.9%) of 289 patients. Patient demographics were similar between groups. There was no statistically significant difference between the two groups in terms of stone diameter and stone localization (median diameter 13.5 vs 15, p=0.285). Patients with postoperative UTI had a higher rate of UTI history (55% vs 20.5%, p=0.000) and longer operative times (62.5 vs 60 min., p=0.008). Rate of pyuria, leukocyte esterase and nitrite positivity were observed more frequently in patients with postoperative UTI. In multivariate analysis, UTI history, prolonged operative time, and nitrite positivity were found to be independent risk factors for postoperative UTI. Conclusion: Nitrite positivity in preoperative urinanalysis, history of UTI and prolonged operation time are the factors that predict the postoperative infection in RIRS for stones between 1-2 cm.

Gunter Sturm

and 38 more

Background: There is controversy whether taking β-blockers or ACE inhibitors (ACEI) is a risk factor for more severe systemic insect sting reactions (SSR) and whether it increases the number or severity of adverse events (AE) during venom immunotherapy (VIT). Methods: In this open, prospective, observational, multicenter trial, we recruited patients with a history of a SSR and indication for VIT. The primary objective of this study was to evaluate whether patients taking β-blockers or ACEI show more systemic AE during VIT compared to patients without such treatment. Results: In total, 1,425 patients were enrolled and VIT was performed in 1,342 patients. Of all patients included, 388 (27.2%) took antihypertensive (AHT) drugs (10.4% took β-blockers, 11.9% ACEI, 5.0% β-blockers and ACEI). Only 5.6% of patients under AHT treatment experienced systemic AE during VIT as compared with 7.4% of patients without these drugs (OR: 0.74, 95% CI: 0.43–1.22, p=0.25). The severity of the initial sting reaction was not affected by the intake of β-blockers or ACEI (OR: 1.14, 95% CI: 0.89–1.46, p=0.29). In total, 210 (17.7%) patients were re-stung during VIT and 191 (91.0%) tolerated the sting without systemic symptoms. Of the 19 patients with VIT treatment failure, 4 took β-blockers, none an ACEI. Conclusions: This trial provides robust evidence that taking β-blockers or ACEI does neither increase the frequency of systemic AE during VIT nor aggravate SSR. Moreover, results suggest that these drugs do not impair effectiveness of VIT. (Funded by Medical University of Graz, Austria; number, NCT04269629)

Nazanin Kermani

and 12 more

Background. Patients with severe asthma may have a greater risk of dying from COVID-19 disease. Angiotensin converting enzyme-2 (ACE2) and the enzyme proteases, transmembrane protease serine 2 (TMPRSS2) and FURIN, are needed for viral attachment and invasion into host cells. Methods. We examined microarray mRNA expression of ACE2, TMPRSS2 and FURIN in sputum, bronchial brushing and bronchial biopsies of the European U-BIOPRED cohort. Clinical parameters and molecular phenotypes, including asthma severity, sputum inflammatory cells, lung functions, oral corticosteroid (OCS) use, and transcriptomic-associated clusters, were examined in relation to gene expression levels. Results. ACE2 levels were significantly increased in sputum of severe asthma compared to mild-moderate asthma. In multivariate analyses, sputum ACE2 levels were positively associated with OCS use and male gender. Sputum FURIN levels were significantly related to neutrophils (%) and the presence of severe asthma. In bronchial brushing samples, TMPRSS2 levels were positively associated with male gender and body mass index, whereas FURIN levels with male gender and blood neutrophils. In bronchial biopsies, TMPRSS2 levels were positively related to blood neutrophils. The neutrophilic molecular phenotype characterised by high inflammasome activation expressed significantly higher FURIN levels in sputum than the eosinophilic Type 2-high or the pauci-granulocytic oxidative phosphorylation phenotypes. Conclusion. Levels of ACE2 and FURIN may differ by clinical or molecular phenotypes of asthma. Sputum FURIN expression levels were strongly associated with neutrophilic inflammation and with inflammasome activation. This might indicate the potential for a greater morbidity and mortality outcome from SARS-CoV-2 infection in neutrophilic severe asthma.

Mehmet Pehlivaoğlu

and 5 more

Aim: This study evaluated the effect of intracavitary levobupivacaine infusion diluted with locally applied isotonic solution for pain control in cystoscopy. Methods: Included in this study are 100 patients who had previously undergone transurethral tumor resection for bladder tumor and were followed up by cystoscopy. The patients were randomized into five groups (n = 20). In the first, second, third, and fourth groups, 4, 6, 8, and 10 mL of levobupivacaine HCl (5.0 mg/mL) were mixed with 26, 24, 22, and 20 mL of isotonic solution, respectively. Hence, the total mixture was 30 mL for each group. The fifth group was the control group. In this group, the standard method commonly used in most clinics was utilized. That is, a gel containing Cathejell-2% lidocaine (25 mg lidocaine) was applied. Cystoscopic interventions were performed with a 17.5 Fr rigid cystoscope and 0°, 30°, and 70° lens. During cystoscopy and 30 min later, the pain status of patients was assessed using the Visual Analogue Scale (VAS), and patient satisfaction was questioned. Results: The mean VAS score during and after the cystoscopy procedure was significantly lower in the levobupivacaine groups compared to the lidocaine group. In addition, patient satisfaction in the levobupivacaine groups was significantly higher than in the lidocaine group. No drug-related side-effects were observed in all groups. Conclusion: Thus, levobupivacaine is a more effective drug than lidocaine alone to control pain during cystoscopy. The use of levobupivacaine is recommended to prevent possible complications of general anesthesia by eliminating the need for the aforementioned as well as its cost-saving advantage.

Yanhui Dong

and 4 more

Groundwater age is often used to estimate groundwater recharge through a simplified analytical approach. This estimated recharge is thought to be representative of the mean recharge between the point of entry and the sampling point. However, given the complexity in actual recharge, whether the mean recharge is reasonable is still unclear. This study examined the validity of the method to estimate long-term average groundwater recharge and the possibility of obtaining reasonable spatial recharge pattern. We first validated our model in producing reasonable age distributions using a constant flux boundary condition. We then generated different flow fields and age patterns by using various spatially-varying flux boundary conditions with different magnitudes and wavelengths. Groundwater recharge was estimated and analyzed afterwards using the method at the spatial scale. We illustrated the main findings with a field example in the end. Our results suggest that we can estimate long-term average groundwater recharge with 10% error in many parts of an aquifer. The size of these areas decreases with the increase in both the amplitude and the wavelength. The chance of obtaining a reasonable groundwater recharge is higher if an age sample is collected from the middle of an aquifer and at downstream areas. Our study also indicates that the method can also be used to estimate local groundwater recharge if age samples are collected close to the water table. However, care must be taken to determine groundwater age regardless of conditions.

Xinyi Guan

and 4 more

Adriana Bustamante

and 3 more

Browse more published preprints

How it works

Upload or create your research work
You can upload Word, PDF, LaTeX as well as data, code, Jupyter Notebooks, videos, and figures. Or start a document from scratch.
Disseminate your research rapidly
Post your work as a preprint. A Digital Object Identifier (DOI) makes your research citeable and discoverable immediately.
Get published in a refereed journal
Track the status of your paper as it goes through peer review. When published, it automatically links to the publisher version.
Learn More
Featured communities
Explore More Communities

Other benefits of Authorea


A repository for any field of research, from Anthropology to Zoology


Discuss your preprints with your collaborators and the scientific community

Interactive Figures

Not just PDFs. You can publish d3.js and graphs, data, code, Jupyter notebooks

Featured templates
Featured and interactive
Journals with direct submission
Explore All Templates