Discover and publish cutting edge, open research.

Browse 10,913 multi-disciplinary research preprints

Most recent

Kyubeom Kim

and 6 more

Objectives: In this study, we designed a new technique for open septal reduction using a polydioxanone (PDS) plate and compared it with closed reduction. Design, Setting, Participants: This study included nineteen consecutive patients with nasoseptal fracture: ten receiving open reduction with a PDS plate (PDS group) and nine undergoing closed reduction (CR group). Open septal reduction was performed after closed reduction for nasal bone fracture. A mucoperichondrial flap was unilaterally elevated, and the deviated septal cartilage was reduced. The PDS plate was inserted horizontally above the vomerine suture. Surgical outcome was analyzed with three-dimensional volumetry and with a quality-of-life scale for nasal obstruction (NOSE scale). Results: Complications included one case of septal perforation in the CR group and one case of PDS exposure and septal hematoma in the PDS group. In the 3D volumetric analysis of the PDS group, the median value of the nasal cavity change significantly differed between 1.14 mL (interquartile range; 0.46 to 2.4) at the preoperative CT scan and 0.33 mL (interquartile range; -0.22 to 1.29) at the postoperative CT scan (**p = 0.0039). The NOSE scale revealed significant improvement in nasal obstruction postsurgically (median value, 42.5 to 7.5; *p = 0.0139) in the PDS group. Conclusion: PDS plates potentially present a new concept of open septal reduction in terms of septal reinforcement compared with the subtractive approach of open septal reduction.

Sinan Eroğlu

and 4 more

Objective: Novel Coronavirus disease is a new infectious agent of the respiratory tract characterized by a severe acute respiratory syndrome. For this disease, there are limited data with regard to the clinical characteristics of the patients and prognostic factors. Study Design: Retrospective Cohort Setting: Secondary Referral Center Methods: We collected data from 213 patients who were hospitalized into COVID-19 isolation with positive PCR test results. We recorded various patient values, including blood test results. We also noted age, gender, additional diseases, duration of discharge, whether they live or die, whether they smoke, and their radiological staging. Results: In CT imaging with a staging of maximum 4 points and minimum 0 points, the mean value resulted in 1.95. The average radiological stage of the dead patients group was reported as 2.56. There was a correlation between the radiological predictor and the outcome status (p-value: 0.002). The number of smokers was 14 (6.5%). Of the 26 patients who died, 3 were smokers and 23 were non-smokers. Conclusion: 14 of the patients in the study were smokers (6.5%). One in four people in Turkey is a smoker, while in COVID-19 isolation service only a 6.5% rate of smoking was observed. That supports the theory that smoking hasn’t negative impact on COVID-19 development. The average radiological stage was reported as 2.56 in the dead patients’s group. There was a correlation between the radiological predictor and the outcome status (p-value: 0.002). It seems that an elevated radiological stage is a predictor of death. Keywords: Covid-19, SARS-CoV-2, smoking, computed tomography, predictor factors. Key points: to learn relations between smoking and covid-19, effect of Ct stages on the disease severity, effect of blood analysis on Covid-19, the parameters in deaths of Covid-19, ratio of smoking in Covid-19 inpatients

Michele Di Mauro

and 8 more

OBJECTIVE. For many years, functional tricuspid regurgitation (FTR) was considered negligible after treatment of left-sided heart valve surgery. The aim of the present network meta-analysis is to summarize the results of four approaches in order to establish the possible gold standard. METHODS A systematic search was performed to identify all publications reporting the outcomes of four approach for FTR, not tricuspid annuloplasty (no TA), suture annuloplasty (SA), flexible (FRA), rigid rings (RRA). All studies reporting at least one the four endpoints (early and late mortality, early and late moderate or more TFR) were included in a Bayesian network meta-analysis. RESULTS There were 31 included studies with 9,663 patients. Aggregate early mortality was 5.3% no TA, 7.2% SA, 6.6% FRA and 6.4% RRA; Early TR moderate-or-more was 9.6%, 4.8%, 4.6% and 3.8%; Late mortality was 22.5%, 18.2%, 11.9% and 11.9%; Late TR moderate-or-more was 27.9%, 18.3%, 14.3% and 6.4%. Rigid or semirigid ring annuloplasty was the most effective approach for decreasing the risk of late moderate or more FTR (–85% vs. no TA; –64% vs. SA; –32% vs. FRA). Concerning late mortality, no significant differences were found among different surgical approaches, however, flexible or rigid rings reduced significantly the risk of late mortality (78% and 47%, respectively) compared with not performing TA mortality. No differences were found for early outcomes. CONCLUSIONS. Ring annuloplasty seems to offer better late outcomes compare to either suture annuloplasty or not performing TA. In particular rigid or semirigid rings provides more stable FTR across time.

Igor Vendramin

and 6 more

Background and aim of the study: Sutureless and rapid-deployment bioprostheses have been introduced as alternative to traditional prosthetic valves to reduce cardiopulmonary and aortic cross-clamp times during aortic valve replacement.These devices have been employed also in extremely demanding surgical settings as underlined in the present review. Methods: A search on PubMed and Medline databases aimed to identify, from the English literature, the reported cases where both sutureless and rapid- deployment prostheses were employed in challenging surgical situations, usually complex reoperations sometimes even performed as a bail out procedures. Results: We have identified 25 patients in whom a sutureless or a rapid-deployment prosthesis were used in complex redo procedures. In 17 patients a failing stentless bioprosthesis was replaced with a sutureless (n=14) or a rapid deployment valve (n=3). Bioprostheses implanted at first operation were mainly Freestyle (n=11) or Prima Plus (n=3) aortic roots, while Perceval (n=13) and Intuity (n=3) were those most frequently employed at reoperation. A failing homograft was replaced in 6 patients using a Perceval (n=5) or an Intuity (n=1) bioprosthesis while a Perceval was used to replace the aortic valve in 2 patients to treat failure of a valve-sparing procedure. All patients survived reoperation and are reported alive 3 months to 4 years postoperatively. Conclusions: Sutureless and rapid-deployment bioprostheses have proved effective in replacing degenerated stentless bioprostheses and homografts in challenging redo procedures. In these setting, they should be considered as a valid alternative not only to traditional prostheses but also in selected cases to transcatheter valve-in-valve solutions.

Li Xue

and 13 more

Background: Erythrocytes and platelets have been demonstrated to play a critical role in inflammatory processes. However, little is known about the diagnostic value of these indices in RA patients. The aim of this study was to evaluate the clinical significance of blood counts-related parameters such as counts of red blood cells (RBCs) and platelets (PLTs), hemoglobin (Hb), red blood cells-platelet ratio (RPR) and hemoglobin-platelet ratio (HPR) in rheumatoid arthritis (RA) and their association with disease activity. Methods: Clinical and laboratory data from 178 RA patients and 164 healthy controls were collected and analyzed. RA patients were divided into inactive group and active group according to disease activity score in 28 joints based on C-reactive protein (DAS28-CRP). The relationship between blood RBC, Hb, PLT, RPR and HPR and DAS28-CRP was detected by Spearman correlation method. Receiver operating characteristic (ROC) curve was used to assess the diagnostic value of these parameters. The predictive role of these indices for RA disease activity was evaluated by logistical regression analysis. Results: Active RA patients exhibited lower levels of blood RBC counts, Hb, HCT, RPR and HPR but significantly higher level of PLT counts compared with those in inactive groups (P < 0.01). Spearman analysis showed that blood RBC counts, HCT, RPR and HPR were negatively but PLT counts were positively related with DAS28-CRP (P < 0.001) in RA. ROC curve analysis revealed that the AUC of RBC and Hb was higher than that of ESR, RF and CCP for distinguishing active RA from inactive group. Logistical regression analyses showed that PLT is an independent predictor for RA disease activity. Conclusion: Blood RBC counts, Hb, RPR and HPR were negatively but PLT counts were positively related with RA disease activity. Blood PLT may act as a novel inflammatory factor for predicting disease activity in RA.

Zhenhua Dang

and 9 more

Organisms have evolved effective and distinct adaptive strategies to survive. Stipa grandis is one of the widespread dominant species on the typical steppe of the Inner Mongolian Plateau, and is regarded as a suitable species for studying the effects of grazing in this region. Although phenotypic (morphological and physiological) variations in S. grandis in response to long-term grazing have been identified, the molecular mechanisms underlying adaptations and plastic responses remain largely unknown. Accordingly, we performed a transcriptomic analysis to investigate changes in gene expression of S. grandis under four different grazing intensities. A total of 2,357 differentially expressed genes (DEGs) were identified among the tested grazing intensities, suggesting long-term grazing resulted in gene expression plasticity that affected diverse biological processes and metabolic pathways in S. grandis. DEGs were identified that indicated modulation of Calvin–Benson cycle and photorespiration metabolic pathways. The key gene´expression profiles encoding various proteins (e.g., Ribulose-1,5-bisphosphate carboxylase/oxygenase, fructose-1,6-bisphosphate aldolase, glycolate oxidase etc.) involved in these pathways suggest that they may synergistically respond to grazing to increase the resilience and stress tolerance of S. grandis. Our findings provide scientific clues for improving grassland use and protection, and identify important questions to address in future transcriptome studies.

Browse more recent preprints

Recently published in scholarly journals

Oktay Ucer

and 3 more

The sinoatrial node in medication-resistant inappropriate sinus tachycardia: to modify or to ablate?Khalil El Gharib1*1Hôtel-Dieu de France, Beirut, Lebanon*Author for correspondence: khalil.gharib@outlook.comKEYWORDS: IST, sinus node modification, sinus node ablation, radiofrequency ablation, surgical ablationNo conflict of interest to discloseFunding: noneInappropriate sinus tachycardia (IST) is defined as a resting heart rate >100 beats per minute (with a mean heart rate >90 beats per minute over 24 hours) associated with highly symptomatic palpitations(1). The syndrome is associated neither with structural heart disease nor with any secondary cause of sinus tachycardia(2) and evidence suggests that enhanced intrinsic automaticity of the sinoatrial node, which can be due to anti-β-adrenergic antibodies, is behind its genesis(3). However, it is benign in terms of clinical outcomes and echocardiographic evidence of ventricular dysfunction(4), being rarely associated with tachycardia-induced cardiomyopathy(3).Patients with IST are essentially treated with ß-blockers to alleviate their symptoms(5). Ivabradine, a drug that inhibits funny calcium channels, particularly abundant in the SA node, showed modest benefit, receiving class IIa recommen­dation in the treatment of IST(4). But, the duration of medical therapy might be indefinite, and, a considerable number of patients would respond inadequately, or have no response, even after prolonged therapy(5). Historically, such patients would have subtotal right atrial excision, atrioventricular junctional ablation with permanent pacemaker implantation, or chemical occlusion of the sinus node artery(6). These options are considered today unacceptable in this setting, and other therapeutic approaches should be unveiled when resistance to medical treatment appears.Electrophysiological study was initially purely diagnostic, but recent advances in technology have allowed us to intervene(7); patients with ventricular and supraventricular tachyarrhythmias are successfully treated with percutaneous catheter procedures. Of these, SA node ablation/ modification has been proposed as alternative approaches in IST that is not responding to medical treatment; trials reported auspicious results, highlighted here.Electrophysiologic mapping to the site of the earliest endocardial activation during either spontaneous sinus tachycardia or isoproterenol-induced sinus tachycardia has rendered these procedures feasible(8). Additionally, combination with intracardiac echocardiography permitted a more accurate electrophysiologic and anatomic localization of the sinoatrial node(9).Sinus node modification is not a focal ablation, but requires complete abolition of the cranial portion of the SA node complex, the one that exhibits the most of the autonomic activity(9). It is defined as successful when the heart rate decreases by 30 beats per minute (bpm) during isoproterenol infusion(8). Short-term success was also defined by other investigators when there was a reduction of the baseline sinus rate to less than 90 bpm and the sinus rate during isoproterenol infusion by more than 20% or by 25%(8). The acute success rate for modification has been varying between 76 and 100 % across trials, while long-term clinical outcomes are modest at best, with reported freedom from IST ranging from 23 to 85%(10).Complications specific to SA node modification include superior vena cava (SVC) syndrome, diaphragmatic paralysis, and sinus node dysfunction(10). And while modification with conventional methods has its setbacks, modification using laser energy can be considered in the setting of IST. This modality creates clear-cut homogenous transmural lesions of the myocardium that comprises the scattered “functional” SA node(11). The burnt myocardium will then heal into a dense fibrous scar, decreasing potential amplitudes. And when adapting laser energy settings to the thickness of the myocardial wall, collateral dam­ages such as esophageal fistulae, lung burns, and phrenic nerve palsy will be avoided(11); thus, this technique may prove itself as a new intriguing alternative for the safe and effective treatment of IST.SA node modification is apt in achieving acute reductions in postprocedural heart rate. However, and as aforementioned, success rates are suboptimal in terms of symptomatic control with a significant recurrence rate(12). Catheter ablation aiming at either total exclusion and obliteration of the SA node has been described and performed, success being defined as a slowing of >50% from the baseline rate of tachycardia along with a junctional escape rhythm(12). With radiofrequency (RF) applications, the earliest local atrial activation time would shift from a cranial location to a more caudal one, usually at the mid-lateral right atrium(5). Reviews have reported that acute success rates were consistently to be as high as 88.9%, with an overall frequency of recurrence of 19.6%, the latter occurring within a wide range of post-ablation intervals, anywhere from a few weeks to several months after the procedure(12). Additionally, Takemoto and colleagues documented a significant drop in B-type natriuretic peptide levels, 6 to 12 months after ablation, suggesting fewer stretching shears on cardiac muscle.Two types of response of the sinus tachycardia to RFA were observed across studies, whether a step-wise reduction in sinus rate accompanying migration of the site of earliest atrial activation in a cranial-caudal direction along the lateral right atrial wall, or an abrupt drop in heart rate in response to RFA at a focal site of earliest atrial activation(13).However, RFA of inappropriate sinus tachycardia requires a large number of applications of radiofrequency energy and is, as in SA node modification, associated with a high recurrence rate(13). Complete remission is achieved only in approximately 50% of patients in some studies(14); longer history of IST and those reporting near syncope/syncope having a higher probability of recurrence(15).While other studies have shown that RF ablation of the SA node can achieve even longer-term reductions in the sinus rate and relief of symptoms in two-thirds of patients with drug-refractory, inappropriate sinus tachycardia(13), aiming specific sites related to the SA node should be elaborated, for better and optimal outcomes Killu and colleagues created a lesion in the arcuate ridge resulting in complete abolition of the tachycardia, since arrhythmias arising in this region may exhibit both electrocardiographic and clinical similarities to IST(16). This has led to consider ablation of the arcuate ridge as a treatment of refractory IST, necessitating larger trials to confirm its potential role.Phrenic nerve injury is a severe and dreaded complication of SN ablation(12). Pericarditis, right diaphragmatic paralysis, and SVC syndrome are other undesirable side effects of the procedures, variously reported in studies. but a common complication was observed in them all, atrial tachyarrhythmias(12). It has been hypothesized that myocardial pathology, such as inflammation and fibrosis, considered iatrogenic due to the ablation procedures, may be promoting arrhythmias both in the region of the SA node, as well as in remote locations(12). Through multivariable analysis, higher resting heart rates post-ablation and smaller cranial-to-caudal shifts have been defined as predictors of atrial arrhythmias(15). In conclusion, catheter ablation could be considered an effective treatment for highly symptomatic, drug-refractory patients, even for those who did not respond to SA node modification(5).The sinus node is located close to the epicardial surface and catheter-based ablations do not always make full-thickness lesions across the atrial muscle, leading to failure of the ablation(17), besides the numerous trabeculae and the widely variable anatomy.Surgical ablation is not a first-line or routine management strategy for IST, but it has been proposed when IST resists or recurs after SN modification/ endocardial ablation(17). Effectively, in several studies, epicardial lesions, through a single small incision in one of the intercostal spaces, successfully slowed heart rate and shifted activation to a more caudal location, and surprisingly, subsequent endocardial lesions led to an even greater drop in heart rate and more caudal site of earliest activation(18). These outcomes were again replicated when using minimally invasive thoracoscopic ablation of the epicardial site of the SA node, concluding of the promising efficacy and the safety of this approach, since it preserves the phrenic nerve(17), although continued follow-up after surgery is required.Medication-resistant IST remains a medical challenge for physicians and cardiologists; and in the era of great advances in interventional cardiology, its treatment remains debatable. Sinus node modification/ ablation is not recommended as first-line therapy in IST, this procedure should be considered only in drug-refractory patients who have severe symptoms(13). Although the number of patients in the available studies is generally small, both procedures have documented an encouraging success rate in the short-term, while being less impressive in the long-term. It has been hypothesized that this discrepancy is due to the relatively large potential area of atrial pacemaker cells(18); modification or ablation may fail to ablate or isolate all the pathways that comprise the functional SA node because they often target the anatomic part and the area of earliest atrial activation(19). Others have explained that the long-term slowing in rhythm fails because these procedures inconsistently produce transmural lesions in the right atrium. Surgical treatment of IST has proposed a solution to the latter conflict when isolating the SA node with a wide cuff of surrounding atrial muscle(19). And with the advent of bipolar RF clamps and minimally invasive cardiac surgical techniques with thoracoscopic guidance, this approach appears more appealing than before, especially when combined with endocardial ablation(19). But again, current data specifies employing these techniques in highly selected cases.


and 10 more

Background: There is insufficient evidence regarding the comparison of Rapid Deployment aortic valve replacement(RDAVR) to TAVR in intermediate-risk patients with severe symptomatic aortic stenosis(AS) Aims: We compare the 2-years outcomes between RDAVR with INTUITY and TAVR with SAPIEN 3 in intermediate-risk patients with AS. Methods: Inclusion criteria: severe AS implanted with RDAVR or TAVR; EUROSCORE II ≥ 4% and clinical evaluation by Heart Team. Regression adjustment for the propensity score was used to compare RDAVR with TAVR(1:1). Primary endpoint: composite criterion of death, disabling stroke or rehospitalization. Secondary endpoints: occurrence of major bleeding post-operative complications, paravalvular regurgitation (PVR)≥2 and patient-prosthesis mismatch(PPM) at 1 month and pacemaker implantation at 2 years. Results: A total of 152 patients were included from 2012 to 2018: 48 in the RDAVR group and 104 in the TAVR group. Mean age was 82.7±6, 51.3% were female, mean Euroscore II was 6.03±1.6% and mean baseline LVEF was 56±13%,mean indexed iEOA was 0.41±0.1cm/m2, mean gradient was 51.7±14.7mmHg. Patients with RDAVR were younger(79.5±6vs82.6±6,p=0.01), at higher risk (EUROSCORE2 6,61±1,8%vs5,63±1,5%, p=0.005), combined surgery was performed in 28 patients(58.3%). Twenty-two patients(45.99%) met the primary outcome in the RDAVR group and 32 patients(66.67%) in the TAVR group. By 1:1propensity score matching analysis, there was a significant difference between both groups in favor of RDAVR(HR=0.58[95%CI:0.34;1.00],p=0.04). No difference were observed in PPM occurrence(0.83;[0.35-1.94];p=0.67),major bleeding events(1.33;[0.47-3.93];p=0.59),PVR≥2(0.33[0-6.28],p=0.46), and pacemaker implantation (0.84[0.25-2.84],p=0.77).Conclusion: RDAVR is associated with better 2-years outcomes than TAVR in intermediate-risk patients with severe symptomatic AS.

Francesca Mori

and 10 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 collections
Explore More Collections

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