Nanozyme-Catalyzed Colorimetric Detection of the Total Antioxidant Capacity in Body Fluids by Paper-Based Microfluidic Chips.

Total antioxidants play a crucial role in human health, and detection of the total antioxidant capacity (TAC) has broad application prospects in fields such as food safety, environmental assessment, and disease diagnosis. However, a long detection time, cumbersome steps, high cost, reliance on professional equipment, and nonportability still remain significant challenges. In this work, an efficient strategy of point-of-care testing (POCT) of the TAC in body fluids by nanozyme-catalyzed colorimetric paper-based microfluidic sensors is proposed. The paper-based microfluidic sensors coupled with a smartphone can reduce testing costs and provide portability. The nanozyme prepared by the solvothermal method presents Michaelis constants of 0.11 and 0.129 mM for H2O2 and TMB, respectively. A method for immobilizing nanozymes and chromogenic agents on a paper-based microfluidic chip is established. Based on smartphone photography and image grayscale extraction, the TAC can be qualitatively detected with a detection limit and linear range of 33.4 and 50-700 µM, respectively. Furthermore, the proposed sensor can realize the one-step quantitative analysis of the TAC in body fluids (blood, saliva, and sweat) within 15 min. The proposed nanozyme-catalyzed colorimetric paper-based microfluidic sensors presented in this study exhibit promising application prospects in the fields of biochemical analysis and POCT.

Early postoperative constrictive pericarditis in China: a single-center retrospective observational study.

Background: The diagnosis, treatment, and prognosis of early postoperative constrictive pericarditis (EPCP) have not been discussed in depth. The objective of this study was to devise and propose a management strategy for EPCP. Methods: In this study, constrictive pericarditis (CP) within 6 months after cardiac surgery was defined as EPCP, and patients were divided into two groups based on intraoperative findings: a parietal thickening group and a visceral thickening group. Results: A total of 20 patients were included in this study, and the incidence rate of recurrent pericardiectomy was 0.32% among all patients undergoing cardiovascular surgery. EPCP after valve surgery occurred in 85.0% of patients. Pleural effusion was the most common preoperative symptom, occurring in 90% of patients. Pericardial thickening occurred in the visceral layer in seven cases and in the parietal layer in 13 cases. There were no differences in comorbidities, C-reactive protein (CRP) level, or erythrocyte sedimentation rate (ESR) between the two groups. Most patients with visceral thickening (83.3%) needed cardiopulmonary bypass (CPB) assistance during surgery and had a longer hospital stay than those with parietal thickening (52.8±21.8 vs. 34.9±13.8 days, P=0.049). Central venous pressure (CVP) was decreased in all patients after pericardiectomy (24.9±6.96 vs. 8.9±2.92 cmH2O, P<0.001), and the cardiac function improved significantly in patients with parietal thickening [New York Heart Association (NYHA) grade ≥ III accounted for 28.6% of patients]. The long-term survival rate of patients with parietal thickening was 92.3% and that of patients with visceral thickening was 57.1%, and there was no significant difference between them (P=0.056). Conclusions: Recurrent episodes of chest tightness, pleural effusion, and elevated CVP within 6 months after cardiac surgery should be considered highly suggestive of EPCP. There are few points of difference between pericarditis with thickening of the parietal and visceral layers. After failure of conservative medical treatment, pericardiectomy results in significant improvements in cardiac function and quality of life, especially in patients with thickening of the parietal layer.

Fe/MOF based platform for NIR laser induced efficient PDT/PTT of cancer.

Introduction: Photodynamic therapy (PDT) and photothermal therapy (PTT) are widely used in the treatment of tumors. However, their application in the treatment of clinical tumors is limited by the complexity and irreversible hypoxia environment generated by tumor tissues. To overcome this limitation, a nanoparticle composed of indocyanine green (ICG) and Fe-MOF-5 was developed. Methods: We prepared F-I@FM5 and measured its morphology, particle size, and stability. Its enzyme like ability and optical effect was verified. Then we used MTT, staining and flow cytometry to evaluated the anti-tumor effect on EMT-6 cells in vitro. Finally, the anti-tumor effect in vivo has been studied on EMT-6 tumor bearing mice. Results: For the composite nanoparticle, we confirmed that Fe-MOF-5 has the best nanozyme activity. In addition, it has excellent photothermal conversion efficiency and generates reactive oxygen species (ROS) under near-infrared light irradiation (808 nm). The composite nanoparticle showed good tumor inhibition effect in vitro and in vivo, which was superior to the free ICG or Fe-MOF-5 alone. Besides, there was no obvious cytotoxicity in major organs within the effective therapeutic concentration. Discussion: Fe-MOF-5 has the function of simulating catalase, which can promote the decomposition of excessive H2O2 in the tumor microenvironment and produce oxygen to improve the hypoxic environment. The improvement of tumor hypoxia can enhance the efficacy of PDT and PTT. This research not only provides an efficient and stable anti-tumor nano platform, but also has broad application prospects in the field of tumor therapy, and provides a new idea for the application of MOF as an important carrier material in the field of photodynamic therapy.

An Analysis of Total Arch Re-Replacement After Proximal Aortic Surgery.

BACKGROUND: After proximal aortic surgery, total arch replacement (TAR) may again be needed because of recurrent dissection or aneurysm. This paper analyzed the relevant data of this technology with hopes of improving cognition and treatment. METHODS: There were a total of 60 eligible cases of secondary TAR after proximal aortic surgery in our center from 2010 to 2020. The primary surgical procedures included aortic valve replacement (AVR), ascending aortic replacement, Bentall, hemi-arch replacement, and thoracic endovascular aortic repair (TEVAR). The data were analyzed using the IBM SPSS Statistics 23.0 for Windows™ and presented as the mean ± standard deviations and direct frequencies, as appropriate. RESULTS: The interval between two operations was 44.8±53.6 months, 24 cases (40%) underwent emergency operation, the recurrence of type A dissection included 51 cases, accounting for 85% of the causes of total arch re-replacement. In the second surgical procedures, the ascending + TAR + stented elephant trunk (SET) implantation accounted for 75.0%. The overall surgical success rate was 98.3%. Postoperative respiratory complications were the most common, including infection, pneumothorax and hemothorax in 21 cases (35.6%). The second most common complication was acute kidney injury (AKI) in six cases (10.2%), and neurological complications took place in three cases (5.1%). The 30-day mortality rate was 15.3% and the 1-, 3- and 5-year survival rates were 96.0%, 84.0%, and 76.0%, respectively. CONCLUSIONS: The recurrence of dissection is the main cause of TAR after proximal aortic surgery, followed by aneurysm and the resurgical criteria for aneurysm needs to be unified. In addition to TAR, SET also is widely used. Despite high early mortality, its long-term prognosis is acceptable.

COVID-19 and the digestive system: A comprehensive review.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is spreading at an alarming rate, and it has created an unprecedented health emergency threatening tens of millions of people worldwide. Previous studies have indicated that SARS-CoV-2 ribonucleic acid could be detected in the feces of patients even after smear-negative respiratory samples. However, demonstration of confirmed fecal-oral transmission has been difficult. Clinical studies have shown an incidence rate of gastrointestinal (GI) symptoms ranging from 2% to 79.1% in patients with COVID-19. They may precede or accompany respiratory symptoms. The most common GI symptoms included nausea, diarrhea, and abdominal pain. In addition, some patients also had liver injury, pancreatic damage, and even acute mesenteric ischemia/thrombosis. Although the incidence rates reported in different centers were quite different, the digestive system was the clinical component of the COVID-19 section. Studies have shown that angiotensin-converting enzyme 2, the receptor of SARS-CoV-2, was not only expressed in the lungs, but also in the upper esophagus, small intestine, liver, and colon. The possible mechanism of GI symptoms in COVID-19 patients may include direct viral invasion into target cells, dysregulation of angiotensin-converting enzyme 2, immune-mediated tissue injury, and gut dysbiosis caused by microbiota. Additionally, numerous experiences, guidelines, recommendations, and position statements were published or released by different organizations and societies worldwide to optimize the management practice of outpatients, inpatients, and endoscopy in the era of COVID-19. In this review, based on our previous work and relevant literature, we mainly discuss potential fecal-oral transmission, GI manifestations, abdominal imaging findings, relevant pathophysiological mechanisms, and infection control and prevention measures in the time of COVID-19.

Clinical Outcome of Reoperation for Mechanical Prosthesis at Aortic Position.

AIM: Redo aortic valve surgery is usually associated with a high risk of mortality and complications. The aim of this study was to investigate the perioperative and long-term outcomes of reoperation after prior mechanical prosthesis implantation at the aortic position. METHOD: The clinical data of 146 consecutive patients who underwent reoperation at the aortic position between 2003 and 2019 were analysed. RESULTS: Mean age was 51.5±12.7 years and 69 (47.3%) were female. The median interval from prior surgery to redo aortic valve surgery was 6 years. The aetiologies were pannus formation with prosthetic aortic stenosis in 62 cases (42.5%), prosthetic valve endocarditis (PVE) in five (3.4%), PVE with perivalvular leakage (PVL) in 16 (11.0%), PVL in 45 (30.8%), thrombosis in seven (4.8%), and aortic disease in 11 (7.5%). As for surgical procedure, aortic valve replacement was performed in 81 cases (55.5%), Bentall in 34 (23.3%), PVL repair in six (4.1%), and pannus debridement in 25 (17.1%). Fourteen (14) (9.6%) patients expired perioperatively. Prolonged ventilation time and postoperative renal failure were proved to be significant independent predictors of mortality according to multivariate analysis. Overall survival was 87.8%±7.4% and 76.4%±15.1% at 5 and 10 years, respectively. Survival was 87.7%±13.7% and 84.2%±15.6% in the pannus group, and 84.5%±12.6% and 74.6%±19.4% in the non-pannus group at 5 and 10 years, respectively (p=0.951). Survival was 87.5%±14.2% and 75.8%±22.7% in the PVL group and 84.7%±11.9% and 81.6%±13.5% in the non-PVL group at 5 and 10 years, respectively (p=0.365). CONCLUSIONS: Pannus formation and PVL are two major indications for reoperation of mechanical prosthesis at the aortic position. Redo aortic valve surgery has a satisfactory outcome but with a high risk of complications. Long-term survival of patients seems not to be related to the aetiology. Final decision-making of redo aortic valve surgery should be based on aetiology.