Discover and publish cutting edge, open research.

Browse 11,012 multi-disciplinary research preprints

Most recent

Yi Liang

and 4 more

Objective: To investigate the connections among social support, stress, and depression. Design: Cross-sectional study. Setting: Guizhou Province in China. Population or Sample: An aggregate of 1,056 expectant ladies, had finished our questionnaire during pregnancy from March to April in 2020. Methods: The Edinburgh prenatal sadness scale, an independent pressure scale, and social support scale evaluated the downturn, stress, and social support of pregnant people during the pestilence. An auxiliary condition model was utilized to examine the immediate and aberrant connection between social support and prenatal misery. Main Outcome Measures: Incidence of depression. Results: During the pandemic time, 73.01% of pregnant ladies experienced prenatal misery. The model is suitable (chi-square = 11.96, CFI = 0.97, RMSEA = 0.07, RMR = 0.03). The auxiliary condition model indicated that the immediate pathway of social support to depression was critical (normalized pathway coefficient = - 0.34), and the aberrant pathway of stress to depression via social support was additionally huge (normalized pathway coefficient = 0.50). Stress partially intercedes the connection between social support and depression. Conclusion: Our discoveries posit that social support is related to an expanded danger of depression. Stress is decidedly corresponding to depression and assumes an interceding position between social support and stress. Thusly, directed mediation ought to be completed to lessen the depression of pregnant ladies and improve their psychological wellness status. Keywords: stress, depression, social support, structural equation model
Background and Purpose: Canthin-6-one (Cant) is an indole alkaloid found in different medicinal plants, reported to be gastroprotective, anti-inflammatory, anti-microbial, anti-diarrheal and anti-proliferative. We aimed to explore Cant in the management of ulcerative colitis (UC) using a trinitrobenzenesulfonic acid (TNBS)-induced rat model. Experimental Approach: Cant (1, 5 and 25 mg/kg) was administered by oral gavage to Wistar rats followed by induction of colitis with TNBS. Macroscopic and histopathological scores, myeloperoxidase (MPO), malondialdehyde (MDA) and reduced glutathione (GSH) were assessed in colon tissues. Pro- (TNF-α, IL-1β and IL-12p70) and anti-inflammatory (IL-10) cytokines, and vascular endothelial growth factor (VEGF) were also quantified. Mitogen-activated protein kinase 14 (MAPK14) and Toll-like receptor-8 (TLR8), as putative targets, were considered through in silico analysis. Key Results: Cant (5 and 25 mg/kg) reduced macroscopic and histological colon damage scores in TNBS-treated rats. MPO and MDA were reduced by up to 61.69% and 92.45%, respectively, compared to TNBS-treated rats alone. Glutathione concentration was reduced in rats administered with TNBS alone (50.00% of sham group), being restored to 72.73% (of sham group) under Cant treatment. TNF-α, IL-1β, IL-12p70 and VEGF were reduced, and anti-inflammatory IL-10 was increased following Cant administration compared to rats administered TNBS alone. Docking ligation results for MAPK14 (p38α) and TLR8 with Cant, confirmed that these proteins are feasible putative targets. Conclusions and Implications: Cant has an anti-inflammatory effect in the intestine by down-regulating immune molecular mediators and decreasing oxidative stress. Therefore, Cant could have therapeutic potential for the treatment of inflammatory bowel disease and related syndromes.

Yudi Zhang

and 4 more

Background and Purpose: Diabetic nephropathy (DN) is a common and severe chronic complication in diabetes mellitus. The purpose of this study was to explore the effect and mechanism of Astragaloside IV (AS-IV) on renal pyroptosis in DN. Experimental Approach: High-fat diet and a small dose of streptozotocin were used to establish the DN model. Rats were treated with vehicle or AS-IV (20-, 40- and 80-mg/kg/day) or valsartan (30mg/kg/day) by gavage. After 12 weeks, animals were euthanized; samples of urine and blood were collected to examine biochemical indicators, advanced glycation end products (AGEs), inflammatory cytokines; kidney tissues were collected for histological observation, TUNEL staining, AGEs, inflammatory cytokines, redox indicators, western blot, and immunohistochemistry. Key Results: Biochemical results showed that AS-IV could significantly alleviate the degree of clinical symptoms and the levels of blood glucose, HbA1C, TG, MDA, AGEs, Interleukin (IL)-1β, and IL-18 while improving the activity of SOD and the secretion and sensitivity of insulin. Histological examination and TUNEL staining indicated that AS-IV attenuated the damage of tissues and cells in the kidney from DN rats. Western blot results revealed that AS-IV relieved the activation of NOX4/TXNIP/NLRP3 pathway and the expression of collagen IV and fibronectin in DN rats. Immunohistochemistry results showed that AS-IV attenuated collagen IV and fibronectin in the kidney from DN rats. Conclusion and Implications: The NOX4/TXNIP/NLRP3 pathway mediated renal pyroptosis could play a crucial role in kidney damage and DN development in rats. Restoration of renal pyroptosis by AS-IV be a potential therapeutic strategy against DN.

sandeep tripathi

and 3 more

Objective: Describe & validate flow index (FiO2×flow rate/weight) to report the degree of respiratory support to children on high flow nasal cannula (HFNC) Methods: Retrospective chart review. Children managed with HFNC from 01/01/15 to 12/31/19. Variables included in the flow index (weight, FiO2, flow rate) and outcomes (hospital and ICU length of stay [LOS], escalation to the ICU) extracted from medical records. Max flow index defined by the earliest timestamp when patients FiO2×Flow rate was maximum. Step-wise regression used to determine the relationship between outcome (length of stay and escalation to ICU) and flow index Results: 1537 patients met the study criteria. Median 1st and maximum flow index of the population 24.1 and 38.1, respectively. Both 1st and maximum flow indexes showed a significant correlation with the LOS (r 0.25 and 0.31). Correlation for the index was stronger than that of the variables used to calculate them and remained significant after controlling for age, race, sex, and diagnoses. Mild, moderate, and severe categories of 1st and max flow index derived using quartiles and showed significant age and diagnosis independent association with LOS. Patients with 1st flow index >20 and maximum flow index >59.5 had increased odds ratio of escalation to ICU (OR 2.39 and 8.08). The 1st flow index had a negative association with rapid response activation. Conclusions: Flow index is a valid measure for assessing the degree of respiratory support for children on HFNC. High flow index associated with longer hospital LOS and the risk of escalation to ICU.
Bird strike is a significant threat to the parts of the flying aircrafts. The wing is a central part, which provides stability to the aircraft. Mostly at wing, bird attack the leading edge. Worldwide aviation regulation FRA, EASA, required 4Ib bird strike on the wing of aircraft, and after this bird strike, aircraft is able to be safely landed. This study aims to investigate the resistance of the wing against the bird strike and damage analysis of the high-velocity bird collision on the model wing, inner structure, spar, and ribs. By using the Coupled Eulerian-Lagrangian (CEL) approach in ABAQUS/Explicit. Our contribution 1) bird strike on a wing with assembled inner structure by aluminium and outer skin composed of unidirectional fiber-reinforced composite material. 2) bird strike on-wing which is similar with the first test in which the difference is of spar designed layers of horizontal plates like a comb. 3) bird strike on-wing which is similar with second model wing difference in this wing put an aluminium leading edge on the skin leading-edge, final to analyze the damage of bird impact on the wing, the velocity of bird strike is 200m/s and analyze the behavior of the bird at this velocity. Resistance behavior of composite skin After penetration in the wing, analyze the impact on the spar and stress on the inner structure. Analysis of the kinetic and internal energy graph and Comparison all of these results and check the performance, which gives an excellent result at this velocity. based on these results suggest which inner part is sensitive.

Elisabeth Bean

and 5 more

Objective To assess the prevalence of endometriosis using pelvic ultrasound examination in women attending for early pregnancy care Design Prospective observational study. Setting A dedicated early pregnancy unit. Population We included 1341 consecutive women who attended for an early pregnancy assessment and had transvaginal ultrasound scans performed by a single clinician. Methods In addition to the presence of endometriosis on ultrasound scan, we collected data on patient demographics and concurrent gynaecological conditions. Data analysis was performed using logistic regression and multivariate analysis. Main outcome measures The prevalence of endometriosis in addition to possible associations with demographic and clinical variables. Results The prevalence of endometriosis in women attending the early pregnancy unit was 4.9% (95% CI 3.8 – 6.2); In 33/66 (50%, 95% CI 37.9 – 62.1) women with endometriosis, this was a new diagnosis made for the first time during their early pregnancy scan. The presence of endometriosis was strongly associated with congenital uterine anomalies (p < 0.001; OR 5.69, 95% CI 2.17 – 14.9) and uterine fibroids (p = 0.004; OR 2.37, 95% CI 1.31, 4.28). Conclusions Endometriosis is present in nearly 5% of women attending for early pregnancy assessment. In half of the women with endometriosis, the diagnosis was made for the first time during pregnancy. We propose that ultrasound may be a useful tool for the detection of endometriosis and to identify pregnant women who may benefit from specialist antenatal care. Funding No funding was obtained for this work. Keywords Endometriosis, Prevalence, Pregnancy, Ultrasonography

Stepan Feduniw

and 5 more

Objective: To investigate the relationship between cannabinoid receptor expression within the placenta after delivery and the problem of preterm delivery. Design, setting, and participants: The retrospective, observational study was conducted on a multicenter material of 150 women. The study group included 115 women after premature delivery. The control group consisted of 35 women after term delivery. Methods. To determine the expression of cannabinoid receptors after the end of the third stage of labour, several sections were taken from the placenta. RNA isolation, reverse transcription, and Real-Time PCR were performed to assess the expression of the cannabinoid receptors in the placenta. Results: Cannabinoid receptor type 2 expression was lower in the placentas of women after preterm delivery. Urinary tract infections and bleeding at any stage of pregnancy occurred statistically more frequently in the study group and correlated with cannabinoid receptor type 2 expression. In the study group, the history of preterm labor, history of intrauterine fetal deaths, pregnancies terminated by a Caesarean section, and uterine tenderness correlated with lower expression of cannabinoid receptor type 2 and 1a. Conclusions: Cannabinoid receptors mRNA were present in human placental tissue during pregnancy. Decreased cannabinoid receptor type 2 expression in preterm delivered placentas should be further investigated, as perinatal endocannabinoid receptor expression could serve as a predicting tool of preterm birth. For example, liquid-based cytology could be used as a noninvasive perinatal method of measuring the expression level of cannabinoid receptors in decidual cells during pregnancy. KEYWORDS: Cannabinoid receptor; CB2; endocannabinoid system; preterm delivery; PTB

Mark Louie Lopez

and 5 more

Studying complex metazoan communities requires taxonomic expertise and laborious work if done using the traditional morphological approach. Nowadays, the popular use of molecular-based methods accompanied by massively parallel sequencing (MPS) provides rapid and higher resolution diversity analyses. However, diversity estimates derived from the molecular-based approach can be biased by the co-detection of environmental DNA (eDNA), pseudogene contamination, and PCR amplification biases. Here, we constructed microcrustacean zooplankton mock communities to compare species diversity and composition estimates from PCR-based methods using genomic (gDNA) and complementary DNA (cDNA), metatranscriptomic transcripts, and morphology data. Mock community analyses show that gDNA mitochondrial cytochrome c oxidase I (mtCOI) amplicons inflate species richness due to environmental and nontarget species sequence contamination. Significantly higher amplicon sequence variant (ASV) and nucleotide diversity in gDNA amplicons than cDNA indicated the presence of putative pseudogenes. Last, PCR-based methods failed to detect the most abundant species in mock communities due to priming site mismatch. Overall, metatranscriptomic transcripts provided estimates of species richness and composition that closely resembled morphological data. The use of metatranscriptomic transcripts was further tested in field samples. The results showed that it could provide consistent species diversity estimates among biological and technical replicates while allowing monitoring of the zooplankton temporal species composition changes using different mitochondrial markers. These findings show that community characterization based on metatranscriptomic transcripts reflects the actual community more than PCR-based approaches.

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