The dark side of SARS-CoV-2 rapid antigen testing: screening asymptomatic patients

Several reports showed SARS-CoV-2 rapid antigen tests (RATs) performances among COVID-19 symptomatic subjects in outpatient settings during periods of highest incidence of infections and high rates of hospital admissions, but few data are present for asymptomatic patients. We investigated the role of RATs in an emergency department, as a novel screening tool before admission for COVID-19 asymptomatic patients. A total of 116 patients were screened on admission in a 250-bed community hospital in Morges, Switzerland. RAT detected 2/7 RT-PCR-positive patients and delivered two false-positive results. These data suggest the non-fiability of RATs screening in this clinical scenario.

Bright conjugated polymer nanoparticles containing a biodegradable shell produced at high yields and with tuneable optical properties by a scalable microfluidic device

This study compares the performance of a microfluidic technique and a conventional bulk method to manufacture conjugated polymer nanoparticles (CPNs) embedded within a biodegradable poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG_5K-PLGA_55K) matrix. The influence of PEG_5K-PLGA_55K and conjugated polymers cyano-substituted poly(p-phenylene vinylene) (CN-PPV) and poly(9,9-dioctylfluorene-2,1,3-benzothiadiazole) (F8BT) on the physicochemical properties of the CPNs was also evaluated. Both techniques enabled CPN production with high end product yields (∼70-95%). However, while the bulk technique (solvent displacement) under optimal conditions generated small nanoparticles (∼70-100 nm) with similar optical properties (quantum yields ∼35%), the microfluidic approach produced larger CPNs (140-260 nm) with significantly superior quantum yields (49-55%) and tailored emission spectra. CPNs containing CN-PPV showed smaller size distributions and tuneable emission spectra compared to F8BT systems prepared under the same conditions. The presence of PEG_5K-PLGA_55K did not affect the size or optical properties of the CPNs and provided a neutral net electric charge as is often required for biomedical applications. The microfluidics flow-based device was successfully used for the continuous preparation of CPNs over a 24 hour period. On the basis of the results presented here, it can be concluded that the microfluidic device used in this study can be used to optimize the production of bright CPNs with tailored properties with good reproducibility.

Life cycle assessment of wastewater treatment options for small and decentralized communities

Sustainability has strong implications on the practice of engineering. Life cycle assessment (LCA) is an appropriate methodology for assessing the sustainability of a wastewater treatment plant design. The present study used a LCA approach for comparing alternative wastewater treatment processes for small and decentralised rural communities. The assessment was focused on two energy-saving systems (constructed wetland and slow rate infiltration) and a conventional one (activated sludge process). The low environmental impact of the energy-saving wastewater treatment plants was demonstrated, the most relevant being the global warming indicator. Options for reduction of life cycle impacts were assessed including materials used in construction and operational lifetime of the systems. A 10% extension of operation lifetime of constructed wetland and slow rate infiltration systems led to a 1% decrease in CO2 emissions, in both systems. The decrease in the abiotic depletion was 5 and 7%, respectively. Also, replacing steel with HDPE in the activated sludge tank resulted in a 1% reduction in CO2 emission and 1% in the abiotic depletion indicator. In the case of the Imhoff tank a 1% reduction in CO2 emissions and 5% in the abiotic depletion indicator were observed when concrete was replaced by HDPE.

Pharmacokinetics of PTT-119 in man

The pharmacokinetics of PTT-119, a new alkylating agent, was studied in 8 advanced cancer patients. PTT-119 disappeared rapidly from plasma after administration at a dose of 3 mg/kg by i.v. bolus injection. The HPLC method shows plasma levels of m-bis (dichloroethyl)amino-phenyl-L-alanine which is the major metabolite of PPT-119. Elimination of the drug from plasma can be described by a one-compartment model. Mean values of 77.8 min for the half-life, 510.8 ml/min for the total plasma clearance and 0.69 l/kg for the volume of distribution were found.