A Comprehensive Overview of Additive Manufacturing Processes Through a Time-Based Classification Model.

The ongoing crisis caused by the COVID-19 pandemic produced major reshuffles on the world map, bringing imbalance, uncertainty, and accumulated stress. Due to supply chain disruptions, the need for innovation has emerged both as a priority and a necessity and three-dimensional printing (3DP) proved to be a primary, smart, effective, and innovative additive manufacturing (AM) method. AM refers to the direct fabrication of complex geometries, using a computer-aided design (CAD) model or a three-dimensional scanner output. This article presents a literature review of AM technologies, chronologically sorted, and proposes a multilevel classification model. The suggested research approach appears a triangular methodology that encompasses the current ISO/ASTM 52900:2021 report. The first objective of this article is to form two double-level classification models of AM processes, depending on the technology and material factors. The second objective is to clarify in which of the proposed categories each AM process is included; and the third one is to investigate if the proposed taxonomy is related to the time spot, in which AM processes were invented. The contribution of this article lies in determining the factors that are crucial for the growth of AM ecosystem. The novelty of the proposed classification lies in the definition of an optimal option for each industrial application based on the different AM processes, the variety of materials, and the evolution of technology over the years. In this way, investing in AM is more systematic and less risky.

Synchronous Insulinoma and Glucagonoma: A Review of the Literature.

BACKGROUND/AIM: Pancreatic neuroendocrine tumors (PNETs) are pancreatic neoplasms with neuroendocrine features, divided into functioning and non-functioning. The non-functioning PNETs are the largest group, and their morbidity is the result of their potential to invade surrounding tissues and metastasize. The functioning PNETs produce hormonal symptoms due to over-secretion of specific hormones. They constitute 1% to 2% of all pancreatic tumors. The use of novel imaging methods has rendered their detection more frequent. Insulinoma, the most common functioning PNET, comprises 35-40% of all functioning PNETs. Its clinical presentation is due to hyperinsulinemia and the subsequent hypoglycemia. Glucagonoma accounts for 5% of all PNETs and is the fourth most frequent functioning PNET, following insulinoma, gastrinoma, and vipoma. Its symptoms are due to the massive secretion of glucagon and ensuing hyperglycemia. The co-existence of two PNETs is a very rare entity. This report aimed to describe cases of concomitant insulinomas and glucagonomas. MATERIALS AND METHODS: A review of the literature was performed using the PubMed database and Cochrane library aiming to identify reported cases of concomitant pancreatic insulinoma and glucagonoma. Specifically, the research was conducted using the keywords, separately and in various combination, including insulinoma, glucagonoma, cystic, pancreatic neuroendocrine tumors and hypoglycemia. Only publications in English were included in the present study. RESULTS: A total of 8 cases of concomitant pancreatic insulinoma and glucagonoma were identified, corresponding to the period 1992-2021. CONCLUSION: Concomitant insulinoma and glucagonoma are rare and challenging. A multidisciplinary approach is necessary for diagnosis, prognosis, and therapy.

Is COVID-19 the "Catalyst" to Incorporate 3D Printing Technology into the Manufacturing Industry?

The contribution of the fight against COVID-19 to the incorporation of 3D printing technology into the manufacturing industry is the research question of this study. By observing the structure of initiatives of hobbyists and enterprises in the 3D printing industry that are printing health care equipment for nursing staff, we conclude that 3D printing technology could be used for mass production under a different production model. We propose two different typologies of a factory's structure, calling them "Adjust-Semi Cloud Factory 1" and "Semi-Cloud Factory 2." To measure the effectiveness of these new types of factories, we propose a framework based on characteristics and aspects of knowledge management.

Dexmedetomidine for the reduction of emergence delirium in children undergoing tonsillectomy with propofol anesthesia: A double-blind, randomized study.

BACKGROUND: Postanesthesia emergence delirium is a motor agitation state complicating pediatric anesthesia. We investigated the efficacy of dexmedetomidine in reducing emergence delirium in children undergoing tonsillectomy with and without adenoidectomy using total intravenous anesthesia with propofol. METHODS: This was a prospective, single-center, double-blind, randomized study. The primary outcome was the presence or absence of emergence delirium with and without dexmedetomidine. Secondary outcomes were emergence delirium severity, time to extubation, cardiovascular stability, and need for additional postoperative analgesia. Eligible were children 3-14 years of age, ASA I or II, scheduled for tonsillectomy with or without adenoidectomy. Patients were randomized to receive dexmedetomidine 1 mcg kg-1 or a volume matched normal saline solution. Presence of emergence delirium and agitation severity was assessed with the Watcha scale 10, 20, and 30 minutes after arrival in the postanesthesia care unit. RESULTS: Sixty children participated to the study, 31 (51.7%) of them were treated with dexmedetomidine. Their mean age was 6.2 years (SD 5.5). Duration of anesthesia and surgery and blood pressure measurements did not differ between groups. Extubation time was not different between groups. The dexmedetomidine group had a significantly lower frequency of emergence delirium compared with no dexmedetomidine after 20 and 30 minutes in postanesthesia care unit: 16.1% and 12.9% at 20 and 30 minutes in the dexmedetomidine group vs 48.3% and 41.4% in in the no dexmedetomidine group. CONCLUSION: Dexmedetomidine 1 mcg kg-1 reduces the incidence and severity of emergence delirium after tonsillectomy with propofol anesthesia without prolonging the extubation time.

Permanent pacemaker implantation in octogenarians with unexplained syncope and positive electrophysiologic testing.

BACKGROUND: Syncope is a common problem in the elderly, and a permanent pacemaker is a therapeutic option when a bradycardic etiology is revealed. However, the benefit of pacing when no association of symptoms to bradycardia has been shown is not clear, especially in the elderly. OBJECTIVE: The aim of this study was to evaluate the effect of pacing on syncope-free mortality in patients aged 80 years or older with unexplained syncope and "positive" invasive electrophysiologic testing (EPT). METHODS: This was an observational study. A positive EPT for the purposes of this study was defined by at least 1 of the following: a corrected sinus node recovery time of >525 ms, a basic HV interval of >55 ms, detection of infra-Hisian block, or appearance of second-degree atrioventricular block on atrial decremental pacing at a paced cycle length of >400 ms. RESULTS: Among the 2435 screened patients, 228 eligible patients were identified, 145 of whom were implanted with a pacemaker. Kaplan-Meier analysis determined that time to event (syncope or death) was 50.1 months (95% confidence interval 45.4-54.8 months) with a pacemaker vs 37.8 months (95% confidence interval 31.3-44.4 months) without a pacemaker (log-rank test, P = .001). The 4-year time-dependent estimate of the rate of syncope was 12% vs 44% (P < .001) and that of any-cause death was 41% vs 56% (P = .023), respectively. The multivariable odds ratio was 0.25 (95% confidence interval 0.15-0.40) after adjustment for potential confounders. CONCLUSION: In patients with unexplained syncope and signs of sinus node dysfunction or impaired atrioventricular conduction on invasive EPT, pacemaker implantation was independently associated with longer syncope-free survival. Significant differences were also shown in the individual components of the primary outcome measure (syncope and death from any cause).

Inverse association of coronary soluble tumor necrosis factor-related apoptosis inducing ligand (sTRAIL) levels to in-stent neointimal hyperplasia.

OBJECTIVES: Soluble tumor necrosis factor-related apoptosis inducing ligand (sTRAIL) has been shown to exert protective action against atherosclerosis. The aim of this study was to investigate potential associations of coronary sTRAIL levels with indices of in-stent neointimal hyperplasia. METHODS: 67 patients who underwent percutaneous coronary intervention with drug-eluting stent were followed up at approximately 12 months with determination of coronary sTRAIL concentration, angiography and intravascular ultrasound evaluation of the stent sites. RESULTS: Mean sTRAIL concentration was 72.2 ± 2.8 pg/ml. sTRAIL was negatively correlated to indices of neointimal hyperplasia and positively correlated to in-stent minimum lumen area (p < 0.001). Neointimal obstruction and maximal in-stent cross-sectional neointima burden in patients in the upper sTRAIL quartile were 3.8 ± 1.2 and 12.6 ± 3.3%, respectively, versus 14.0 ± 0.7 and 49.8 ± 2.7% in the lower quartile (p < 0.001 for both). sTRAIL levels were significantly lower in patients with binary restenosis (48.7 ± 3.0 vs. 75.2 ± 2.9 pg/ml; p < 0.001). In the multivariate analysis, sTRAIL was an independent predictor of neointimal hyperplasia. CONCLUSION: This study demonstrates a negative association of sTRAIL to in-stent neointima formation. The potential pathophysiologic substrate of this effect implicates modulation of apoptosis in various cell types. These observations should prompt further evaluation of the link between sTRAIL and in-stent restenosis.

Novel direct factor IIa and Xa inhibitors: mechanisms of action and preclinical studies.

The need to overcome certain limitations of the existing anticoagulant agents (heparin, LMWH and VKAs) and to achieve more convenient long-term anticoagulation has fueled the quest for the "ideal anticoagulant", an agent that would exert at least similar antithrombotic effects with a substantially improved pharmacologic profile and significantly less bleeding complications. The major disadvantages of the traditional agents were the narrow therapeutic window with serious drug and food interactions and the need for regular blood monitoring. Coagulation factors IIa and Xa have proved the most attractive pharmacologic targets due to their key role in the coagulation process and the opportunity of blocking thrombin generation before the level of thrombin production that results in amplification of the anticoagulant effect while preserving some of thrombin hemostatic effect. This review summarizes the mechanism of action of some of the most promising novel oral direct factor IIa and Xa inhibitors with a focus on published preclinical trials that led to their clinical development.