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OBJECTIVE: To evaluate whether cervical pessary effectively reduces the preterm birth < 37 weeks rate in patients who have not delivered after an episode of arrested preterm labor. PATIENTS AND METHODS: Retrospective cohort study was conducted on singleton pregnant patients admitted to our institution between January 2016 and June 2021 for threatened preterm labor and who had a cervical length < 25 mm. Women in whom a cervical pessary was placed were considered as exposed, while women in whom expectant management was preferred were considered as unexposed. The primary outcome was the rate of preterm birth before 37 weeks. A targeted maximum likelihood estimation was used to estimate the average treatment effect of cervical pessary by adjusting for a-priori-defined confounders. RESULTS: A cervical pessary was placed in 152 (36.6%) patients (exposed), while the remaining 263 (63.4%) were managed expectantly (unexposed). The adjusted average treatment effect was -14% (-18 to -11%), -17% (-20 to -13%), and -16% (-20 to -12%) for preterm birth < 37 weeks, < 34 weeks, and < 32 weeks, respectively. The average treatment effect for adverse neonatal outcomes was -7% (-8 to -5%). No difference in gestational weeks at delivery between exposed and unexposed emerged when gestational age at first admission was > 30.1 gestational weeks. CONCLUSIONS: The positioning of a cervical pessary placement may be evaluated to reduce the risk of a subsequent preterm birth after an episode of arrested preterm labor in pregnant patients with onset of symptoms before 30 gestational weeks. [ABSTRACT FROM AUTHOR]

In 1953, during the building restoration of San Michele church (Bono, Sardinia, 16th–19th Century), a high number of disarticulated skeletons were recovered. From a group of 412 hip bones, two of these, affected by several pathological lesions, were analysed. The two coxal bones can be referred to the same individual, an adult man. A multi-analytical study, started with the purpose of investigating the bone pathology, was extended to characterize the mineral components of a large representative set of bones from the same ossuary, all attributed to adult men who lived in the region four-two centuries ago. A quantitative ICP-AES analysis for Ca, Fe, Mg, Mn, Na, Pb and Zn was executed, and a chemometric investigation on the results was performed. This approach gave evidence of the effects of diagenesis, allowed some hypothesis of the incidence of the known dietary habits on bone composition, and completely differentiated the pathological bones from those of a normal population on the basis of the mineral composition. Moreover, porosity, crystallinity and FT-IR analysis were conducted on both non- and pathological sample. [ABSTRACT FROM AUTHOR]

It is well-known from the literature that an interaction e ff ect on crack propagation arises when a specimen or a component is subjected to variable amplitude loading. In dependence of the applied load sequence, a certain amount of retardation or acceleration onto fatigue crack growth rate can then be observed if compared to the constant amplitude case. In the case of structural ductile materials, the interaction phenomenon is mainly addressed by the local plasticity at the crack tip and can be explained, from a global point of view, by adopting the crack closure concept. Considering the applicative case of railway axles, a good correlation between crack growth interaction e ff ects under variable amplitude loading and the amount of plasticity-induced crack closure has been previously derived by the authors, relatively to the standardized EA1N steel. The other standardized European steel for railway axles, a 25CrMo4 grade named EA4T, is instead considered in the present research, as well as an high strenght steel grade. An experimental campaign was carried on this material, using SE(T) specimens, in order to understand and quantify the interaction e ff ects arising from relevant load sequences derived from service. Firstly, tests were performed directly applying the acquired load time history. Eventually, the load history was transformed into an equivalent block loading sequence and applied to di ff erent specimens varying the number of cycles of each single block. Finally, the experimental outcomes were modeled adopting both a strip yield model and a simple no-interaction approach, in order to quantify the possible interaction e ff ects. The modeling was carried out considering di ff erent experimental techniques for deriving the crack growth and threshold behaviors of the material, i.e. the traditional Δ K-decreasing technique and the compression pre-cracking one. [ABSTRACT FROM AUTHOR]

Abstract: An experimental study on two structural steels (normalized C45 and 25CrMo4 grades) was conducted to determine the influence of the adopted technique onto the threshold SIF value. For both the tested materials, the standard approach used to pre-crack the specimens showed to have an influence on determining the thresholds, generating SIF higher than the ones estimated adopting compression pre-cracking techniques. This observation can have a huge effect on both life prediction and inspection intervals for a real structure. An example of life prediction was carried out applying the Nasgro equations, with the experimentally estimated parameters, to the propagation of a crack located at the T-transition of a generic railway axle, assumed to be built using the two tested steel grades. [Copyright &y& Elsevier]

Abstract: Crack initiation and growth in full scale railway axle in A1T mild steel have been studied, under three points rotating bending loading conditions and artificial rainwater as corrosive environment. A surface plastic replication technique has been used along with optical microscopy and Scanning Electron Microscopy to monitor the environment assisted fatigue at various stages.A modified Murtaza and Akid empirical model has been employed to predict the corrosion fatigue crack growth rates and a reasonable agreement has been found between experimental and calculated lifetime. [Copyright &y& Elsevier]

Abstract: An experimental study on two structural steels (normalized C45 and 25CrMo4 grades) was conducted to determine the influence of the adopted technique onto the threshold SIF value. For both the tested materials, the standard approach used to pre-crack the specimens showed to have an influence on determining the thresholds, generating SIF higher than the ones estimated adopting compression pre-cracking techniques. This observation can have a huge effect on both life prediction and inspection intervals for a real structure. An example of life prediction was carried out applying the Nasgro equations, with the experimentally estimated parameters, to the propagation of a crack located at the T-transition of a generic railway axle, assumed to be built using the two tested steel grades. [Copyright &y& Elsevier]

Corrosion fatigue is an important topic in the evaluation of the structural integrity of railway axles. In fact, several recent axle failures have been attributed to the presence of corrosion pits and axle surface corrosion. Despite the importance of this issue, existing EN standards do not precisely quantify the effect that corrosion or corrosion-fatigue might have on the fatigue strength of a railway axle. Consequently, there is a need to have a better understanding of this problem. In this paper, two main lines of research have been adopted with a view to investigating the issues regarding the corrosion fatigue properties of AlN steel. The first line of research assesses the morphology and the statistical distribution of corrosion defects present on the surface of retired axles together with the detrimental effect of the defects detected on the in-air fatigue strength of AlN steel. The second line of research examines the fatigue properties of AlN steel in the presence of artificial rainwater. The results of the analysis show that the corrosion typically found on axles is significant from a point of view of fatigue properties and that the fatigue life of AlN steel is strongly affected by the presence of a mildly corrosive substance like rainwater. Fatigue test results are consistent with the fatigue strength reduction outlined in the BASS technical recommendations. [ABSTRACT FROM AUTHOR]

The need to optimize inspection intervals of railway wheelsets involves, among other aspects, a reliable estimation of fatigue crack growth in the axles. With this in mind, the present paper focuses on the description of the considered axle made of A1N steel, and on some typical load spectra. Application of an opportune algorithm, derived from the dedicated soft-ware NASGRO®, made it possible to obtain life predictions in terms of cycles, and to discuss the influence of service loads. Life estimates were then analysed together with probability of detection curves of different non-destructive testing techniques in order to determine the total probability of observing, during periodical inspections, cracks or defects. [ABSTRACT FROM AUTHOR]

Barth syndrome is an X-linked disorder characterized by dilated cardiomyopathy, cyclic neutropenia, skeletal myopathy, abnormal mitochondria, and growth deficiency. The primary defect is a mutation in the TAZ gene on the X chromosome at Xq28, resulting in abnormal phospholipid biosynthesis and cardiolipin deficiency. To date, there has been no systematic evaluation of the cardiac phenotype. We report five cases of cardiac arrest and/or placement of an internal cardiac defibrillator with documented ventricular arrhythmia. We suggest that ventricular arrhythmia is part of the primary phenotype of the disorder and that patients should be screened accordingly. [ABSTRACT FROM AUTHOR]

The reduction of the total life cycle cost of the whole wheelset requires an optimization of inspection intervals for axles. Such components can, in most European countries, endure more than 30 years of service life. During this time, they are subjected to frequent non-destructive testing (NDT) inspections. It is therefore important to assess the influence of design options, such as hollow versus solid axles or mild versus high strength steel, on the prospective crack propagation life of an axle. In the present paper two dedicated crack propagation algorithms (namely AFGROW and NASGRO) will be applied to the estimation of inspection intervals of railway axles by comparing the properties of two widely used steels. [ABSTRACT FROM AUTHOR]

Background: Freedom from rejection in pediatric heart transplant recipients is highly variable across centers. This study aimed to assess the center variation in methods used to diagnose rejection in the first-year post-transplant and determine the impact of this variation on patient outcomes., Methods: The PHTS registry was queried for all rejection episodes in the first-year post-transplant (2010-2019). The primary method for rejection diagnosis was determined for each event as surveillance biopsy, echo diagnosis, or clinical. The percentage of first-year rejection events diagnosed by surveillance biopsy was used to approximate the surveillance strategy across centers. Methods of rejection diagnosis were described and patient outcomes were assessed based on surveillance biopsy utilization among centers., Results: A total of 3985 patients from 56 centers were included. Of this group, 873 (22%) developed rejection within the first-year post-transplant. Surveillance biopsy was the most common method of rejection diagnosis (71.7%), but practices were highly variable across centers. The majority (73.6%) of first rejection events occurred within 3-months of transplantation. Diagnosis modality in the first-year was not independently associated with freedom from rejection, freedom from rejection with hemodynamic compromise, or overall graft survival., Conclusions: Rejection in the first-year after pediatric heart transplant occurs in 22% of patients and most commonly in the first 3 months post-transplant. Significant variation exists across centers in the methods used to diagnose rejection in pediatric heart transplant recipients, however, these variable strategies are not independently associated with freedom from rejection, rejection with hemodynamic compromise, or overall graft survival., (Copyright © 2021 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study was to determine the efficacy and risks of radiofrequency ablation of various forms of supraventricular tachycardia after Mustard and Senning operations for d-transposition of the great arteries., Background: In this patient group, the reported success rate of catheter ablation of intraatrial reentry tachycardia is about 70% with a negligible complication rate. There are no reports of the use of radiofrequency ablation to treat other types of supraventricular tachycardia., Methods: Standard diagnostic criteria were used to determine supraventricular tachycardia type. Appropriate sites for attempted ablation included 1) intraatrial reentry tachycardia: presence of concealed entrainment with a postpacing interval similar to tachycardia cycle length; 2) focal atrial tachycardia: a P-A interval < or =-20 ms; and 3) typical variety of atrioventricular (AV) node reentry tachycardia: combined electrographic and radiographic features., Results: Nine Mustard and two Senning patients underwent 13 studies to successfully ablate all supraventricular tachycardia substrates in eight (73%) patients. Eight of eleven (73%) patients having intraatrial reentry tachycardia, 3/3 having typical AV node reentry tachycardia, and 2/2 having focal atrial reentry tachycardia were successfully ablated. Among five patients having intraatrial reentry tachycardia (IART) and not having ventriculoatrial (V-A) conduction, two suffered high-grade AV block when ablation of the systemic venous portion of the medial tricuspid valve/inferior vena cava isthmus was attempted., Conclusions: Radiofrequency catheter ablation can be effectively and safely performed for certain supraventricular tachycardia types in addition to intraatrial reentry. A novel catheter course is required for slow pathway modification. High-grade AV block is a potential risk of lesions placed in the systemic venous medial isthmus.

Pediatric cardiologists and cardiologists who examine adults frequently receive referrals of adolescents and young adults with chest pain. Chest pain in this age group is most likely noncardiac in origin, which often creates a diagnostic dilemma for the consultant in terms of the etiology and extent of evaluation. This review presents the noncardiac and cardiac etiologies of chest pain in adolescents and young adults, as well as the key features of a patient's history and physical examination that help delineate cardiac from noncardiac chest pain. In addition, we present recommendations for the cardiac consultant regarding the evaluation and management of adolescents and young adults referred with the complaint of chest pain.