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Background: Two-stage exchange arthroplasty is a feasible treatment for chronic PJI (periprosthetic joint infection) of total hip arthroplasty (THA). However, there are large numbers of patients who are unable to ultimately receive reimplantation after resection arthroplasty owing to uncontrolled infection and multiple comorbidities. The purpose of the current study was to identify patient-related risk factors and reasons for being unable to undergo revision THA. Methods: Individuals undergoing resection arthroplasty for chronic PJI treatment from 2013 to 2020 at our institution were retrospectively reviewed. A variety of patient comorbidities, laboratory data, isolated pathogens, and follow-up status were collected for analysis. Results: A total of 84 patients (46 men and 38 women) with a 2.7 ± 2.1-year follow-up were analyzed. Thirty-eight (45.2%) patients eventually underwent revision THA, while the other 46 (54.8%) did not receive reimplantation during follow-up. The patients without receiving reimplantation had higher Charlson comorbidity index (CCI) score (3.1 ± 2.9 versus 1.2 ± 1.5; p = 0.001). Lower cumulative incidence of receiving reimplantation was observed in patients with chronic kidney disease (log-rank test, p = 0.019), anemia (p = 0.011), presence of initial fever (p = 0.030), and oxacillin-resistant strain infection (p = 0.030). The most common reasons for not receiving reimplantation were uncontrolled infection, unstable medical conditions, and death. The patients without reimplantation had a relatively higher mortality rate (log-rank test, p = 0.002). Conclusion: Chronic hip PJI with poor medical conditions or oxacillin-resistant strain infection decreased the chance of undergoing revision surgery. These patients had unfavourable outcomes and a higher mortality rate after resection arthroplasty. [ABSTRACT FROM AUTHOR]

Background: Postoperative stroke is a severe and potentially disabling complication following surgical intervention for acute type A aortic dissection (ATAAD). This retrospective study aims to compare the early and late outcomes between patients who had hemorrhagic and ischemic stroke after undergoing ATAAD repair surgery. Methods: Between January 2007 and June 2020, a total of 685 consecutive patients underwent ATAAD repair at our institution. Patients who had a preoperative stroke or were unconscious at presentation were excluded from this study. Of the 656 included for analysis, 102 (15.5%) patients had a postoperative stroke confirmed by computed tomography angiography. The strokes were classified into the ischemia group (n = 83, 12.7%) and hemorrhage group (n = 19, 2.9%). Clinical features, surgical information, postoperative complications, modified Rankin Scale (mRS) scores after discharge, and 5-year cumulative survival rates were compared. Results: Demographics, comorbidities, and presentations of ATAAD were similar between the two groups, except a higher rate of preoperative antithrombotic medication was found in the hemorrhage group. The hemorrhage group was associated with a higher complexity of aortic arch replacement, longer cardiopulmonary bypass, and aortic clamping times than the ischemia group. A higher in-hospital mortality rate (42.1% versus 20.5%; p = 0.048) and a higher median mRS score at the 3-month follow-up after discharge (6[3–6] versus 4[2–6]; p = 0.027) were found in the hemorrhage group. The hemorrhage group showed a lower 5-year cumulative survival rate (23.4% versus 57.8%; p = 0.003) compared with the ischemia group. Conclusions: Postoperative hemorrhagic stroke was associated with poorer neurological outcomes and lower survival rates than those with ischemic stroke. Patients who have complex arch replacement, long cardiopulmonary bypass and aortic clamping times are at risk for postoperative hemorrhagic stroke and should have intensive neurological surveillance for early diagnosis and treatment after ATAAD repair surgery. [ABSTRACT FROM AUTHOR]

Quantitative polymerase chain reaction (qPCR) is the most important quantitative sensing technique for pathogens, especially for emerging pandemics such as the coronavirus outbreak this year. The qPCR chip and device were investigated to meet the unmet needs of ultrafast inspection time, high accuracy, and small system volume. Therein, the fluorescence intensity was the most important signal in qPCR quantification of DNA amplifications, which is essential not only in the confirmative diagnosis of positive or negative infection, but also in the assessment of viral load for therapeutic and quarantine decision making. As the target DNAs got amplified, the interaction of fluorescence dye and double strand DNA will generate fluorescence signal proportional to amplified DNA in the intensity when excited by certain wavelength. A miniature spectro-detector was employed to receive the fluorescence scattering for digital output of the intensity in the qPCR chip in this study, and the optical simulation and actual experimental design and results according to the optical simulation results were performed to study the effect of the stray light shutter (SLS) in the improvement of the signal in fluorescence detection. The analysis results showed that the signal-to-noise ratio (SNR) of the fluorescence can be enhanced significantly for five times of the control using the SLS with a shape of extended component aperture, where the protruding structure was positioned away from the center. The experimental results showed that fluorescence intensity can be enhanced by 15.50% and 9.86% when adding the above shape of SLS in resin- and in glass-based chip, respectively. The results also demonstrated that the optical setup had good stability and repeatability in fluorescence detection, and variation was less than 1.00%. Our results can provide important reference to the development of qPCR chip to obtain the high SNR fluorescence signal in DNA quantification process. [ABSTRACT FROM AUTHOR]

Organoaluminum complexes containing a monoanionic pincer ligand, N -(2-pyridylmethyl)-5- tert -butyl-pyrrol-2-ylaldiminate ([PyIm-py]−), have been prepared and structurally characterized. Solution NMR studies of [PyIm-py]AlEt 2 and [PyIm-py]Al i Bu 2 reveal the diastereotopic nature of their α-hydrogen atoms. Complex [PyIm-py]AlMe 2 is an active catalyst in controlled ring-opening polymerization of ε-caprolactone. [Display omitted] Organoaluminum chemistry employing the pyridine functionalized pyrrolylaldiminate ligand N -(2-pyridylmethyl)-5- tert -butyl-pyrrol-2-ylaldiminate ([PyIm-py]−) is described. The ligand precursor H[PyIm-py] was prepared in nearly quantitative yield from the condensation reaction of 5- tert -butylpyrrole-2-carbaldehyde with 2-aminomethylpyridine. Alkane elimination reactions of H[PyIm-py] with AlR 3 (R = Me, Et, i Bu) in toluene at −35 °C generated corresponding organoaluminum derivatives [PyIm-py]AlR 2 in moderate to high yields. The 1H NMR studies of [PyIm-py]AlEt 2 and [PyIm-py]Al i Bu 2 revealed the diastereotopic nature of their α-hydrogen atoms. The solid state structures of [PyIm-py]AlMe 2 and [PyIm-py]AlEt 2 were determined by X-ray crystallography. Complex [PyIm-py]AlMe 2 is an active catalyst in controlled ring-opening polymerization of ε-caprolactone. [ABSTRACT FROM AUTHOR]