Ultra-High-Performance Concrete (UHPC): A State-of-the-Art Review

The interest of researchers in UHPC has increased over the past decade. It is crucial to understand the structural behavior of reinforced UHPC (R/UHPC) components under various loading conditions before they can be used as a replacement for conventional concrete. Although several studies on ultra-high-performance concrete (UHPC) have been conducted, the knowledge is scattered, and no one can easily judge the performance and methodology of UPHC. Therefore, the purpose of this study was to review the research studies already carried out on UHPC. The review focuses on the materials’ physical and chemical composition, mechanical and durability characteristics, fire resistance, and environmental benefits of UHPC. Design considerations for effectively utilizing UHPC in structural elements are also presented. The best UHPFRC mixture is obtainable with a steel fiber content of 2–3% and a water-to-cement ratio of 0.2–0.3. The review also discusses the essentials recommendation for future research on UHPC.     

B-cell lymphoma-associated hemophagocytic lymphohistiocytosis: A case report

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by an exaggerated but dysregulated immune response resulting in hyperinflammation, with a potential for progression to multiple organ dysfunction and failure. Infectious diseases, inflammatory disorders, malignancies and immunodeficiency syndromes are known triggers of HLH in adults. The present study reported the case of a middle-aged man with HLH triggered by B-cell lymphoma who was successfully treated with dexamethasone; etoposide, prednisone, vincristine, cyclophosphamide, hydroxy-doxorubicin and rituximab chemotherapy; and multiple intrathecal methotrexate with a good outcome.     

Prior intake of new oral anticoagulants adversely affects outcome following surgery for acute type A aortic dissection

Open in a separate window OBJECTIVESOral anticoagulation prior to emergency surgery is associated with an increased risk of perioperative bleeding, especially when this therapy cannot be discontinued or reversed in time. The goal of this study was to analyse the impact of different oral anticoagulants on the outcome of patients who underwent emergency surgery for acute type A aortic dissection (ATAAD).METHODSThis was a single-centre retrospective study of patients treated with oral anticoagulation at the time of surgery for ATAAD. Outcomes of patients on new oral anticoagulant (NOAC) therapy were compared to respective outcomes of patients on Coumadin. Additionally, a survival analysis was performed comparing these 2 groups with patients who were operated on with no prior anticoagulation.RESULTSBetween January 2013 and April 2020, a total of 437 patients (63.8 ± 11.8 years, 68.4% male) received emergency surgery for ATAAD; 35 (8%) were taking oral anticoagulation at the time of hospital admission: 20 received phenprocoumon; 14, rivaroxaban; and 1, dabigatran. Compared to Coumadin, NOAC was associated with a greater need for blood-product transfusions and haemodynamic compromise. Operative mortality was 53% in the NOAC group and 30% in the Coumadin group. A 5-year survival analysis showed no significant difference between the NOAC and the Coumadin group (P = 0.059). Compared to 402 patients treated during the study period without anticoagulation, patients taking NOAC had significantly worse survival (P = 0.001), whereas that effect was not observed in patients undergoing surgery who were taking Coumadin (P = 0.99).CONCLUSIONSEmergency surgery for ATAAD in patients taking NOAC is associated with high morbidity and mortality. NOAC are a major risk factor for uncontrollable bleeding and haemodynamic compromise. New treatment strategies must be defined to improve surgical outcomes in these high-risk patients.     

Clinical profile and long term outcomes of eyes with choroidal detachment following trabeculectomy

Purpose:To assess the long-term outcomes of choroidal detachments (CDs) in eyes following trabeculectomy.Methods:Retrospective comparative case series. Data of patients with CDs following trabeculectomy (5-year period) with or without cataract surgery with a minimum of 3 months of follow-up were included.Results:In total, 45 patients with CDs following trabeculectomy were included. The mean age was 63.27 ± 8.68 years, (M:F = 2:1); 29 of 45 eyes (64.4%) had a baseline IOP of >24 mm Hg. Patients had a median follow-up of 22.2 (IQR: 16.2–30.5) months. Further, 10 of 45 eyes (22.2%) had CDs following suture lysis. The median onset of choroidal detachment from the time of surgery was 16.0 (IQR: 11–36) days. The mean BCVA improved from 0.62 ± 0.28 to 0.24 ± 0.27 (P < 0.001) and mean IOP increased from 4.07 ± 2.66 to 11.20 ± 5.31 (P < 0.001) at last visit. The cumulative success rates were 76.4% (95% CI: 48.4–90.5) in POAG eyes and 79.3% (95% CI: 62.8–89.1) in PACG eyes (P = 0.547). Medical management was the mainstay in all patients. Four of 45 (8.88%) patients underwent subsequent choroidal drainage.Conclusion:Choroidal detachment following modern-day trabeculectomy has favorable long-term visual acuity and IOP outcomes. There was no difference in the long-term surgical success of trabeculectomy with choroidal detachments in primary angle-closure and open-angle glaucoma eyes. Long-term follow-up is essential to prevent chronic hypotony and trabeculectomy failure.     

Investigation of Bamboo Fibrous Tensile Strength Using Modified Weibull Distribution

Ethiopia has a large coverage of bamboo plants that are used for furniture making and house building. So far, researchers have not studied the strength of Ethiopian bamboo fibers, which are utilized for composite applications. The current study measured the strength of bamboo fibers based on various testing lengths and calculated the predictive tensile strength using a modified Weibull distribution. Moreover, the quality of the extraction machine is evaluated based on shape and sensitivity parameters. This research paper incorporates the coefficient of variation of the fiber diameters, considering the defects distribution through the length for measuring the predictive strength of the fibers. The fiber diameters were calculated using the area weight methods, which had its density measured using a Pycnometer. It has been examined that as the testing gauge length and coefficient variation of fiber diameter simultaneously increased, the tensile strength of the bamboo fibers decreased. The shape parameter, sensitivity parameter, and characteristic strength of Injibara bamboo (Y. alpina) are 6.02–7.83, 0.63, and 459–642 MPa, whereas Kombolcha bamboo (B. oldhamii) are 5.87–10.21, 0.33, and 408–638 MPa, as well as Mekaneselam bamboo (Y. alpina) are 5.86–9.63, 0.33 and 488–597 MPa, respectively.     

Chronic hyperammonemia alters the circadian rhythms of corticosteroid hormone levels and of motor activity in rats

Patients with liver cirrhosis may present hepatic encephalopathy with a wide range of neurological disturbances and alterations in sleep quality and in the sleep‐wake circadian rhythm. Hyperammonemia is a main contributor to the neurological alterations in hepatic encephalopathy. We have assessed, in an animal model of chronic hyperammonemia without liver failure, the effects of hyperammonemia per se on the circadian rhythms of motor activity, temperature, and plasma levels of adrenal corticosteroid hormones. Chronic hyperammonemia alters the circadian rhythms of locomotor activity and of cortisol and corticosterone levels in blood. Different types of motor activity are affected differentially. Hyperammonemia significantly alters the rhythm of spontaneous ambulatory activity, reducing strongly ambulatory counts and slightly average velocity during the night (the active phase) but not during the day, resulting in altered circadian rhythms. In contrast, hyperammonemia did not affect wheel running at all, indicating that it affects spontaneous but not voluntary activity. Vertical activity was affected only very slightly, indicating that hyperammonemia does not induce anxiety. Hyperammonemia abolished completely the circadian rhythm of corticosteroid hormones in plasma, completely eliminating the peaks of cortisol and corticosterone present in control rats at the start of the dark period. The data reported show that chronic hyperammonemia, similar to that present in patients with liver cirrhosis, alters the circadian rhythms of corticosteroid hormones and of motor activity. This suggests that hyperammonemia would be a relevant contributor to the alterations in corticosteroid hormones and in circadian rhythms in patients with liver cirrhosis. © 2009 Wiley‐Liss, Inc.     

Green aspects of photocatalysts during corona pandemic: a promising role for the deactivation of COVID-19 virus

The selection of a facile, eco-friendly, and effective methodology is the need of the hour for efficient curing of the COVID-19 virus in air, water, and many food products. Recently, semiconductor-based photocatalytic methodologies have provided promising, green, and sustainable approaches to battle against viral activation via the oxidative capabilities of various photocatalysts with excellent performance under moderate conditions and negligible by-products generation as well. Considering this, recent advances in photocatalysis for combating the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are inclusively highlighted. Starting from the origin to the introduction of the coronavirus, the significant potential of photocatalysis against viral prevention and -disinfection is discussed thoroughly. Various photocatalytic material-based systems including metal-oxides, metal-free and advanced 2D materials (MXenes, MOFs and COFs) are systematically examined to understand the mechanistic insights of virus-disinfection in the human body to fight against COVID-19 disease. Also, a roadmap toward sustainable solutions for ongoing COVID-19 contagion is also presented. Finally, the challenges in this field and future perspectives are comprehensively discussed involving the bottlenecks of current photocatalytic systems along with potential recommendations to deal with upcoming pandemic situations in the future.

Photocatalysts are green, eco-friendly, clean and sustainable and could be a solution to combat COVID-19 because of potential features of various types of metal oxides against viral inactivation via the generation of reactive oxidative species.     

The Role of Streptococcal Cell-Envelope Proteases in Bacterial Evasion of the Innate Immune System

Bacteria possess the ability to evolve varied and ingenious strategies to outwit the host immune system, instigating an evolutionary arms race. Proteases are amongst the many weapons employed by bacteria, which specifically cleave and neutralize key signalling molecules required for a coordinated immune response. In this article, we focus on a family of S8 subtilisin-like serine proteases expressed as cell-envelope proteases (CEPs) by group A and group B streptococci. Two of these proteases known as Streptococcus pyogenes CEP (SpyCEP) and C5a peptidase cleave the chemokine CXCL8 and the complement fragment C5a, respectively. Both CXCL8 and C5a are potent neutrophil-recruiting chemokines, and by neutralizing their activity, streptococci evade a key defence mechanism of innate immunity. We review the mechanisms by which CXCL8 and C5a recruit neutrophils and the characterization of SpyCEP and C5a peptidase, including both in vitro and in vivo studies. Recently described structural insights into the function of this CEP family are also discussed. We conclude by examining the progress of prototypic vaccines incorporating SpyCEP and C5a peptidase in their preparation. Since streptococci-producing SpyCEP and C5a peptidase are responsible for a considerable global disease burden, targeting these proteases by vaccination strategies or by small-molecule antagonists should provide protection from and promote the resolution of streptococcal infections.