Spray freeze dried niclosamide nanocrystals embedded dry powder for high dose pulmonary delivery.

Based on the drug repositioning strategy, niclosamide (NCL) has shown potential applications for treating COVID-19. However, the development of new formulations for effective NCL delivery is still challenging. Herein, NCL-embedded dry powder for inhalation (NeDPI) was fabricated by a novel spray freeze drying technology. The addition of Tween-80 together with 1,2-Distearoyl-sn-glycero-3-phosphocholine showed the synergistic effects on improving both the dispersibility of primary NCL nanocrystals suspended in the feed liquid and the spherical structure integrity of the spray freeze dried (SFD) microparticle. The SFD microparticle size, morphology, crystal properties, flowability and aerosol performance were systematically investigated by regulating the feed liquid composition and freezing temperature. The addition of leucine as the aerosol enhancer promoted the microparticle sphericity with greatly improved flowability. The optimal sample (SF- 80D-N20L2D2T1) showed the highest fine particle fraction of ∼47.83%, equivalently over 3.8 mg NCL that could reach the deep lung when inhaling 10 mg dry powders.

The effect of COVID-19 restrictions on atmospheric new particle formation in Beijing

During the COVID-19 lockdown, the dramatic reduction of anthropogenic emissions provided a unique opportunity to investigate the effects of reduced anthropogenic activity and primary emissions on atmospheric chemical processes and the consequent formation of secondary pollutants. Here, we utilize comprehensive observations to examine the response of atmospheric new particle formation (NPF) to the changes in the atmospheric chemical cocktail. We find that the main clustering process was unaffected by the drastically reduced traffic emissions, and the formation rate of 1.5 nm particles remained unaltered. However, particle survival probability was enhanced due to an increased particle growth rate (GR) during the lockdown period, explaining the enhanced NPF activity in earlier studies. For GR at 1.5–3 nm, sulfuric acid (SA) was the main contributor at high temperatures, whilst there were unaccounted contributing vapors at low temperatures. For GR at 3–7 and 7–15 nm, oxygenated organic molecules (OOMs) played a major role. Surprisingly, OOM composition and volatility were insensitive to the large change of atmospheric NOx concentration;instead the associated high particle growth rates and high OOM concentration during the lockdown period were mostly caused by the enhanced atmospheric oxidative capacity. Overall, our findings suggest a limited role of traffic emissions in NPF.

Genetic screening for hypertension and COVID-19 reveals functional variant of SPEG associated with severe COVID-19 in female (preprint)

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused more than 6.4 million deaths worldwide and is still spreading among global populations. The prevalent comorbidity between hypertension and severe COVID-19 suggests common genetic factors may affect the outcome of both diseases. As both hypertension and severe COVID-19 demonstrate sex-specific prevalence, common genetic factors among the two diseases may display gender-based differential associations. By evaluating COVID-19 association signals of 172-candidate hypertension single nucleotide polymorphisms derived from more than one million European individuals in two severe COVID-19 genome-wide association studies from UK BioBank with European ancestry, we revealed one functional cis expression quantitative trait locus of SPEG (rs12474050) associating with both hypertension and severe COVID-19 in female. The risk allele of rs12474050*T is correlated with lower SPEG expression in muscle-skeletal, heart-atrial appendage, and heart-left ventricle; among these tissues the SPEG expression is higher in female than in male COVID-19 patients. Further analysis revealed SPEG is mainly expressed in cardiomyocytes in heart and is upregulated upon SARS-CoV-2 infection, with significantly higher folder change of SPEG expression observed in female compared to male COVID-19 patients. Taken together, our analyses strongly suggest the involvement of SPEG in both hypertension and severe COVID-19 in female, which provides new insights for sex-specific effect of severe COVID-19 in female.

Does It Matter to Establish a Strategic Partnership for COVID-19 Prevention and Control? The Perspective of Multiple Distances in Emerging Economies

The rapid spread of the COVID-19 pandemic in early 2020 has impacted the politics, economy and society of countries around the world. The public health diplomacy system through which developed countries in Europe and America used to provide vertical one-way assistance to developing countries faces huge challenges. How emerging economies can cooperate to fight the pandemic on the basis of mutual trust and mutual benefit has become an urgent issue. In this paper, we examine the impact of political mutual trust on the effectiveness of pandemic prevention and control from the perspective of establishing strategic partnerships between emerging economies. Furthermore, taking into account the huge differences between emerging economies, this paper explores institutional distance, cultural distance, and geographical distance—the adjustment effect of the control effect. Studies have shown that the improvement of political mutual trust is conducive to the formation of a community of shared futures between countries and has a positive effect on curbing the spread of the pandemic. The increase of the three-dimensional distance of institutions, culture, and geography will weaken the effect of establishing strategic partners for pandemic prevention and control. This paper explores a new model of horizontal international cooperation among emerging economies, and provides a reference for emerging economies to deal with common globalization issues in the future.

Electromagnetically-driven integrated microfluidic platform using reverse transcription loop-mediated isothermal amplification for detection of severe acute respiratory syndrome coronavirus 2.

Rapid, sensitive and accurate diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of great need for effective quarantining and treatment. Real-time reverse-transcription polymerase chain reaction requiring thermocyling has been commonly used for diagnosis of SARS-CoV-2 though it may take two to 4 h before lengthy sample pretreatment process and require bulky apparatus and well-trained personnel. Since multiple reverse transcription loop-mediated isothermal amplification (multiple RT-LAMP) process without thermocycling is sensitive, specific and fast, an electromagnetically-driven microfluidic chip (EMC) was developed herein to lyse SARS-CoV-2 viruses, extract their RNAs, and perform qualitative analysis of three marker genes by on-chip multiple RT-LAMP in an automatic format within 82 min at a limit of detection of only ∼5000 copies per reaction (i.e. 200 virus/ µL). This compact EMC may be especially promising for SARS-CoV-2 diagnostics in resource-limited countries.

Political polarization drives online conversations about COVID-19 in the United States.

Since the outbreak in China in late 2019, the novel coronavirus (COVID-19) has spread around the world and has come to dominate online conversations. By linking 2.3 million Twitter users to locations within the United States, we study in aggregate how political characteristics of the locations affect the evolution of online discussions about COVID-19. We show that COVID-19 chatter in the United States is largely shaped by political polarization. Partisanship correlates with sentiment toward government measures and the tendency to share health and prevention messaging. Cross-ideological interactions are modulated by user segregation and polarized network structure. We also observe a correlation between user engagement with topics related to public health and the varying impact of the disease outbreak in different U.S. states. These findings may help inform policies both online and offline. Decision-makers may calibrate their use of online platforms to measure the effectiveness of public health campaigns, and to monitor the reception of national and state-level policies, by tracking in real-time discussions in a highly polarized social media ecosystem.

An integrated microfluidic platform featuring real-time reverse transcription loop-mediated isothermal amplification for detection of COVID-19.

An integrated microfluidic platform (IMP) utilizing real-time reverse-transcription loop-mediated isothermal amplification (RT-LAMP) was developed here for detection and quantification of three genes of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; i.e., coronavirus diseases 2019 (COVID-19)): RNA-dependent RNA polymerase, the envelope gene, and the nucleocapsid gene for molecular diagnosis. The IMP comprised a microfluidic chip, a temperature control module, a fluidic control module that collectively carried out viral lysis, RNA extraction, RT-LAMP, and the real-time detection within 90 min in an automatic format. A limit of detection of 5 × 103 copies/reaction for each gene was determined with three samples including synthesized RNAs, inactive viruses, and RNAs extracted from clinical samples; this compact platform could be a useful tool for COVID-19 diagnostics.

One-Step Rapid Quantification of Serum Neutralizing Antibody after COVID-19 Vaccination by a High-Throughput Nanoplasmonic Sensor Platform (preprint)

The COVID-19 vaccination efficacy depends on serum production level of the neutralizing IgG antibody (NA) specific to the receptor binding domain of SARS-Cov-2 spike protein. Therefore, a high-throughput rapid assay to measure the total SARS-CoV-2 NA level is urgently needed for COVID-19 serodiagnosis, convalescent plasma therapy, vaccine development, and assessment. Here, we developed a nanoplasmonic immunosorbent assay (NanoPISA) platform for one-step rapid quantification of SARS-CoV-2 NAs in clinical serum samples for high-throughput evaluation of COVID-19 vaccine effectiveness. The NanoPISA platform enhanced by the use of nanoporous hollow gold nanoparticle coupling was able to detect SARS-CoV-2 NAs with a limit of detection of 0.1 ng/mL within 15 min. The one-step NanoPISA for SARS-CoV-2 NA detection in clinical specimens yielded good results, comparable to those obtained in the gold standard seroneutralization test and the surrogate virus neutralizing ELISA. Collectively, our findings indicate that the one-step NanoPISA may offer a rapid and high-throughput NA quantification platform for evaluating the effectiveness of COVID-19 vaccines.