Development of Lateral Flow Fluorescence Assay for the Detection of Trypanosoma

Trypanosoma such as Trypanosoma brucei and Trypanosoma cruzi, the causative agents for African sleeping sickness and Chagas disease, respectively, have important influence on human health. The methods such as microscopic examination, immunological methods, and molecular methods are used for the identification and detection of Trypanosoma, but none of these methods are ideal to mass screening of samples such as onset of outbreak, epidemiological surveys, and blood unit screening. Therefore, there is a need for an assay which can rapidly, sensitively and specifically detect Trypanosoma. In this study, Ru(bpy)32+-doped silica nanoparticles (RuSNP) were used to target nucleic acid sequences in a lateral flow fluorescent assay. This assay was developed to improve the sensitivity and lower the limit of detection as compared to the traditional lateral flow assay. The assay targeted both the spliced leader sequence as well as the polyA tail of the mRNA. The surface of spherical RuSNP was modified by glycidoxypropyl trimethoxysilane (GOPTMS). Amine-terminated oligonucleotides as a bioreceptor were immobilized onto the RuSNP via the interaction between the NH2 and the epoxy group of the GOPTMS. The conjugate complexes formed were immobilized on the conjugate pad, and the capture oligonucleotides used for test and control lines were immobilized on the nitrocellulose membrane. The effects of the amount of RuSNP, GOPTMS, amine-capped oligonucleotides, and capture oligonucleotides on the test line on the performance of the test strips were investigated and optimized. The fluorescence intensity was evaluated by using a fluorescent microplate reader. The experimental results showed that the nucleic acid sequence-based and RuSNP-labeled lateral flow assay was very sensitive compared with the gold-labeled test strips and the chemiluminescent test strips we developed previously, and that the limit of detection (LOD) of the test strips developed is 0.4 fmol. The LOD can further be reduced about one order of magnitude when dipstick format was used

Complete and safe resection of challenging retroperitoneal tumors: anticipation of multi-organ and major vascular resection and use of adjunct procedures.

BackgroundRetroperitoneal tumors are often massive and can involve adjacent organs and/or vital structures, making them difficult to resect. Completeness of resection is within the surgeon's control and critical for long-term survival, particularly for malignant disease. Few studies directly address strategies for complete and safe resection of challenging retroperitoneal tumors.MethodsFifty-six patients representing 63 cases of primary or recurrent retroperitoneal tumor resection between 2004-2009 were identified and a retrospective chart review was performed. Rates of complete resection, use of adjunct procedures, and perioperative complications were recorded.ResultsIn 95% of cases, complete resection was achieved. Fifty-eight percent of these cases required en bloc multi-organ resection, and 8% required major vascular resection. Complete resection rates were higher for primary versus recurrent disease. Adjunct procedures (ureteral stents, femoral nerve monitoring, posterior laminotomy, etc.) were used in 54% of cases. Major postoperative complications occurred in 16% of cases, and one patient died (2% mortality).ConclusionsComplete resection of challenging retroperitoneal tumors is feasible and can be done safely with important pre- and intraoperative considerations in mind

COVID-19 two years on: A review of COVID-19-related empirical research in major tourism and hospitality journals

Purpose: This study aims to provide a timely review of the COVID-19-related empirical research published in 19 quartile one (Q1) and quartile two (Q2) tourism and hospitality journals in social science citation index (SSCI). Design/methodology/approach: A total of 407 COVID-19-related empirical papers were collected from the 19 SSCI Q1 and Q2 tourism and hospitality journals via Scopus database. Thematic content analysis was supplemented with Leximancer software to identify the research themes/subthemes, research methods and countries/regions of research. Findings: The study found studies of COVID-19’s impact on consumer behaviour predominate in number, followed by studies on response actions and recovery strategies, impact on industry or sectors and impact on workers and employees. Based on the research themes identified, a knowledge mapping framework was produced. Over 70 % of the studies used quantitative methods with quantitative survey as the dominant method of data collection. The USA and China were found to be the most studied countries. Research limitations/implications: The study reviewed empirical research papers until January 2022 and covered most of the COVID-19-related empirical works in the field. An overview of the current state of COVID-19-related empirical research was provided with some critical discussions and suggestions for future research topics. Originality/value: The findings give researchers a clear index for the current state of the art of COVID-19 research in hospitality and tourism. The paper provides practical implications for industry practitioners to retrieve relevant knowledge from the recent COVID-19-related literature in tourism and hospitality in coping with practical challenges brought by the COVID-19 pandemic