Search

The outbreak of coronavirus disease 2019 (COVID-19) has disproportionately affected patients with comorbidities, including recipients of solid organ and hematopoietic stem cell transplants (SCT). Upon recovery from COVID-19, the degree of the immunological protection from reinfection remains unclear. Here we describe a 33-year-old patient with erythropoietic protoporphyria (EPP) who had undergone liver transplantation with splenectomy followed by allogeneic SCT in 2013 after an initial failed liver and umbilical cord transplant. The patient developed mild upper respiratory symptoms in the spring of 2020 and was found to have anti-SARS-CoV2 antibodies suggesting past infection. A comprehensive analysis of T cell functionality in peripheral blood from this patient revealed robust in vitro responses against SARS CoV2 antigens Spike (S) 1 and 2, membrane (M) and nucleoprotein (NP), comparable to the reactivity against common antigens from CMV, EBV, Ad and BK viruses, while only low reactivity was seen in healthy donors without documented history of COVID-19. Moreover, the patient displayed a marked recognition of counterpart antigens from related human coronaviruses (hCoVs) 229E, OC43, NL63 and HKU1. Thus, despite lifelong immunosuppression, this survivor of COVID-19 retained a remarkable degree of immunocompetence and showed broad-spectrum T cell memory specific for SARS-CoV2 and related hCoVs including less studied hCoV M and NP antigens. The study highlights the role of cellular immunity after natural COVID-19 infection, suggesting broader use of T cell assays as a tool for risk stratification, measurement of immunocompetence and/or post-infection or post-vaccination protection, and possible T cell-based adoptive immunotherapy strategies in high-risk patients.

Rationale and Objectives This study aimed to validate the feasibility of using virtual monochromatic spectral computed tomography (CT) with isotonic low iodine concentration contrast medium for VX2 hepatic tumors. Materials and Methods Sixty New Zealand white rabbits with implanted VX2 hepatic tumors underwent two-phase contrast-enhanced spectral CT imaging on the 14th day after tumor implantation. They were randomly divided into groups A, B, and C, with 20 rabbits each (group A: 270 mg I/mL, monochromatic spectral images; group B: 370 mg I/mL, conventional 120 kVp images, 100% filtered back projection [FBP]; group C: 270 mg I/mL, conventional 120 kVp images, 100% FBP). Group A was further divided into two subgroups (subgroup A1: 100% FBP; subgroup A2: 50% FBP + 50% adaptive statistical iterative reconstruction). Objective evaluation (signal-to-noise ratio [SNR], contrast-to-noise ratio [CNR], and image noise), subjective rating score (image noise score, anatomical details score, overall image quality score, and lesion conspicuity score), CT dose index volume, and dose length product were compared between groups during two-phase contrast enhancement. The detection rates of the four groups were calculated as percentages. Results Image noise (SNR and CNR) among the four groups was statistically significant ( P 0.05). The image noise in group A2 was lower than in group A1, but higher than that in groups B and C ( P 0.05). SNR and CNR in group A2 were the highest, followed by group A1, and group C was the lowest ( P 0.05 for all). The image noise score of group A2 was higher than that of the other three groups. In terms of the anatomic details score, the overall image quality score, and the lesion conspicuity score, the images of group A2 were superior to that of groups A1 and C. For hepatic tumor diameters more than or equal to 1.0 cm and less than 3.0 cm, group A achieved a higher detection rate than groups B and C. The CT dose index volume, dose length product, and effective dose in group A were significantly lower than that in groups B and C ( P 0.05). On average, group A reduced the effective radiation dose by 27.2% compared to group B, whereas group B reduced the effective radiation dose by 28% compared to group C. Group A reduced the iodine load by 22.86% compared to group B. Conclusions The use of monochromatic images combined with 50% adaptive statistical iterative reconstruction with an isotonic low concentration contrast medium of 270 mg I/mL can optimize image quality, reduce image noise, increase detection rate for small tumors, and decrease radiation dose and iodine load in hepatic tumor CT examinations.

Excessive inflammation induced by cytokine storm and coagulation disorders is considered the primary characteristic of smoke inhalation-induced acute lung injury (SI-ALI). Glucocorticoids such as methylprednisolone (MP) are commonly used to treat patients with inflammatory diseases; however, the management of ALI or acute respiratory distress syndrome (ARDS) remains controversial. We explored the effects of different MP doses and durations in a rat SI-ALI model. SI-ALI model rats had a high mortality rate and severe lung injury with proinflammatory, procoagulant, and pro-fibrotic changes. We found that a medium MP dose (4 mg/kg) markedly improved survival rates compared with low (0.4 mg/kg) and high (40 mg/kg) doses in the acute phase. A medium dose significantly attenuated lung injury, and reduced proinflammatory cytokine production and neutrophil infiltration into alveoli. Both medium and high MP doses improved coagulation and fibrinolysis conditions compared with low-dose MP. We also explored the effect of different durations of MP treatment on attenuating fibrotic changes in late-phase SI-ALI. Pro-fibrotic chemokine levels were gradually increased, followed by an increase in collagen and fibrin deposition after smoke inhalation. Three and 7-day MP treatments significantly attenuated this process, which was reflected by a reduction in pro-fibrotic chemokine levels. There was no significant difference between 3- and 7-day treatments. We report that a medium MP (4 mg/kg) dose significantly reduced inflammation and coagulation disorders, as well as acute-phase mortality. Three-day MP treatment may sufficiently attenuate fibrotic changes in late-phase SI-ALI.

The design and manufacture of a second-generation adaptive damper composed of an electrorheological (ER) fluid, and piezoelectric ceramics is presented in this paper. Compared with the first-generation dampers, there are three aspects of modification adopted in the design of this. These include (a) the number, mode of arrangement, and electrocircuit connecting style of piezoceramics, (b) load applying mechanism, and (c) hole-channel in the concentric cylinder electrode. The experiment conducted shows that the amplitude of frequency response function decreases drastically in the frequency range of 220-250 Hz under an exciting acceleration amplitude of 3.5 g (g the gravitational acceleration) and the resonance frequency moves from 198 to 208 Hz. The new damper excels the old one in antivibration performance. In the on-off state model, numerical simulations clearly show the vibration suppression effect of the damper. The design method of combining the ER fluid and the piezoelectric ceramic as a self-coupled system can be implemented extensively in other control systems, such as acoustic insulation and control.

This paper aims at proposing a framework for modelling the safety of an engineering system with various types of uncertainties using a fuzzy rule-based evidential reasoning (FURBER) approach. In the framework, parameters used to define the safety level, including failure rate, failure consequence severity and failure consequence probability, are described using fuzzy linguistic variables; a fuzzy rule-base designed on the basis of a belief structure is used to capture uncertainty and non-linear relationships between these parameters and the safety level; and the inference of the rule-based system is implemented using the evidential reasoning algorithm. A numerical study of collision risk analysis for a kind of offshore platform is used to illustrate the application of the proposed approach.

Background Severe acute pancreatitis (SAP) is associated with systemic inflammation, immunoparalysis, and sepsis, and may lead to vital organ failure and death. We evaluated the efficacy of serum interleukin 17 (IL-17) concentration for predicting eventual SAP severity and the clinical benefits of removing IL-17 by continuous veno-venous hemofiltration (CVVH). Methods Patients were divided into 2 groups according to severity: Grade 1 (n = 18, SAP without organ dysfunction) and Grade 2 (n = 18, SAP with organ dysfunction). 20 healthy volunteers served as controls. All patients underwent 24-h CVVH and blood samples were taken at 0, 6, 12, and 24 h for measurement of bacterial load and serum IL-17, IL-6, and endotoxin. Clinical condition was graded by the sequential organ failure assessment (SOFA) score. Results Baseline IL-17, IL-6, endotoxin, and bacterial load were higher in Grade 2 patients. SOFA scores improved significantly, and serum IL-17, IL-6, endotoxin, and bacterial load decreased significantly in all patients after CVVH. Serum IL-17 was significantly and positively correlated with IL-6, bacterial load, and endotoxin during CVVH treatment. In addition, post-CVVH serum IL-17 was directly correlated with SOFA scores on days 1 and 7, and with duration of hospital stay. Non-survivors showed both higher SOFA scores on day 1 and higher baseline IL-17 than survivors. Conclusions Earlier and higher serum IL-17 elevation predicted prolonged hospitalization, organ failure, and death, possibly by disrupting gut barrier function. CVVH can remove inflammatory cytokines from serum, including IL-17 and IL-6, thereby attenuating the inflammatory response and diminishing associated systemic complications.

Sensorless tension control of belt-driven robotic arm, based on dual-motor synchronous automation system, requires one obtains the instantaneous magnitude of tension difference, between right hand side and left hand side of the belt that driving the robot arm. This in turn depends on the instantaneous speed interaction with the processed unit, through the internal friction of high viscous liquid contact. In this paper, we present the nonlinear liquid friction identification on the base of stator current with present and its previous two values. The fundamental equation of dual motor systems for liquid friction control, principles of mass-flow systems and the novel method of finite tension difference using particle swarm optimization trained neural network are presented. A three-layer feed-forward neural network is optimized. The simulation based on the limited factory experiment test data shows the system with Swarm Intelligence method is practical for thick adhesive application and processing automation on industry assembling lines.

Objective To evaluate the efficacy of endovascular treatment of giant intracranial aneurysms with Willis covered stents (Micro-Port, Shanghai, China). Clinical presentation The endovascular treatment of two cases of giant intracranial aneurysm was successfully accomplished by the placement of Willis covered stents specially designed for intracranial use. Both patients presented with symptoms of cavernous mass effect that resulted from a giant aneurysm in the cavernous segment of the internal carotid artery. Intervention Three Willis covered stents were successfully placed in two patients. Immediate postprocedure angiograms demonstrated some endoleak of the aneurysms. In one patient, the endoleak was eliminated and complete exclusion of the aneurysms was confirmed with follow-up angiography. However, the other patient required the placement of a new Willis covered stent. Conclusion The use of covered stents in intracranial vascular structures is a feasible method to treat selected cases of intracranial giant aneurysms. It is suggested that patients who present with compressive mass effect caused by large or giant aneurysms are the best candidates for covered stent placement, but potential complications should be considered carefully before the stenting procedure.