Accurate quantification of DNA using on-site PCR (osPCR) by characterizing DNA amplification at single-molecule resolution.

Despite the need in various applications, accurate quantification of nucleic acids still remains a challenge. The widely-used qPCR has reduced accuracy at ultralow template concentration and is susceptible to nonspecific amplifications. The more recently developed dPCR is costly and cannot handle high-concentration samples. We combine the strengths of qPCR and dPCR by performing PCR in silicon-based microfluidic chips and demonstrate high quantification accuracy in a large concentration range. Importantly, at low template concentration, we observe on-site PCR (osPCR), where only certain sites of the channel show amplification. The sites have almost identical ct values, showing osPCR is a quasi-single molecule phenomenon. Using osPCR, we can measure both the ct values and the absolute concentration of templates in the same reaction. Additionally, osPCR enables identification of each template molecule, allowing removal of nonspecific amplification during quantification and greatly improving quantification accuracy. We develop sectioning algorithm that improves the signal amplitude and demonstrate improved detection of COVID in patient samples.

Ultrafast Nucleic Acid Detection Equipment with Silicon-Based Microfluidic Chip.

Recently, infectious diseases, such as COVID-19, monkeypox, and Ebola, are plaguing human beings. Rapid and accurate diagnosis methods are required to preclude the spread of diseases. In this paper, an ultrafast polymerase chain reaction (PCR) equipment is designed to detect virus. The equipment consists of a silicon-based PCR chip, a thermocycling module, an optical detection module, and a control module. Silicon-based chip, with its thermal and fluid design, is used to improve detection efficiency. A thermoelectric cooler (TEC), together with a computer-controlled proportional-integral-derivative (PID) controller, is applied to accelerate the thermal cycle. A maximum of four samples can be tested simultaneously on the chip. Two kinds of fluorescent molecules can be detected by optical detection module. The equipment can detect viruses with 40 PCR amplification cycles in 5 min. The equipment is portable, easily operated, and low equipment cost, which shows great potential in epidemic prevention.

The impact of COVID-19 on the mental health of pregnant women in Shanghai, China.

Background: COVID-19 has dramatically impacted people's health, especially mental health. This study aimed to compare the psychological status of pregnant women before and after the COVID-19 outbreak. Methods: Participants were recruited (from September 29, 2019, to November 5, 2020) and screened by the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder Scale (GAD-7). The study participants were categorized into three groups based on two turning-points: January 23, 2020, when China initiated a locked-down strategy, and May 11, 2020, when Shanghai started to ease the COVID-19 measures. Multivariable logistic regression was used to determine the factors associated with depression and anxiety in pregnant women. We used enter method for variable selection; only variables with P <0.10 were included in the final model. Results: We recruited 478 pregnant women. After the outbreak, the depression rate (PHQ-9 ≥ 5) increased by 12.3% (from 35.4 to 47.7%), and the anxiety rate (GAD-7 ≥ 5) was stable (13.3 vs. 16.2%). The multivariable logistic regression results further confirmed that the odds of depression in pregnant women increased 81% after the outbreak (aOR = 1.81, 95%CI: 1.16-2.84). However, the median depression scale score was still statistically higher after the pandemic situation was stable (5.0 vs. 4.0) compared to the outbreak period. Conclusion: The depression rate increased among pregnant women after the outbreak and was not recovered after the ease of COVID-19 measures in Shanghai. Health institutes should pay attention to the long-term influence of the pandemic.

Global view on virus infection in non-human primates and implications for public health and wildlife conservation.

Viruses can be transmitted from animals to humans (and vice versa) and across animal species. As such, host-virus interactions and transmission have attracted considerable attention. Non-human primates (NHPs), our closest evolutionary relatives, are susceptible to human viruses and certain pathogens are known to circulate between humans and NHPs. Here, we generated global statistics on VI-NHPs based on a literature search and public data mining. In total, 140 NHP species from 12 families are reported to be infected by 186 DNA and RNA virus species, 68.8% of which are also found in humans, indicating high potential for crossing species boundaries. The top 10 NHP species with high centrality in the NHP-virus network include two great apes (Pan troglodytes, Pongo pygmaeus) and eight Old World monkeys (Macaca mulatta, M. fascicularis, M. leonina, Papio cynocephalus, Cercopithecus ascanius, C. erythrotis, Chlorocebus aethiops, and Allochrocebus lhoesti). Given the wide distribution of Old World monkeys and their frequent contact with humans, there is a high risk of virus circulation between humans and such species. Thus, we suggest recurring epidemiological surveillance of NHPs, specifically Old World monkeys that are in frequent contact with humans, and other effective measures to prevent potential circulation and transmission of viruses. Avoidance of false positives and sampling bias should also be a focus in future work.

Therapeutic options of TCM for organ injuries associated with COVID-19 and the underlying mechanism.

BACKGROUND: Coronavirus disease-2019 (COVID-19) caused by infection with severe acute respiratory coronavirus-2 (SARS-CoV-2) has been spreading rapidly throughout China and in other countries since the end of 2019. The World Health Organization (WHO) has declared that the epidemic is a public health emergency of international concerns. The timely and appropriate measures for treating COVID-19 in China, which are inseparable from the contribution of traditional Chinese medicine (TCM), have won much praise of the world. PURPOSE: This review aimed to summarize and discuss the essential role of TCM in protecting tissues from injuries associated with COVID-19, and accordingly to clarify the possible action mechanisms of TCM from the perspectives of anti-inflammatory, antioxidant and anti-apoptotic effects. METHODS: Electronic databases such as Pubmed, ResearchGate, Science Direct, Web of Science, medRixv and Wiley were used to search scientific literatures. RESULTS: The present review found that traditional Chinese herbs commonly used for the clinical treatment of organ damages caused by COVID-19, such as Scutellaria baicalensis, Salvia miltiorrhizaSalvia miltiorrhiza, and ginseng, could act on multiple signaling pathways involved in inflammation, oxidative stress and apoptosis. CONCLUSION: TCM could protect COVID-19 patients from tissue injuries, a protection that might be, at least partially, attributed to the anti-inflammatory, antioxidant and anti-apoptotic effects of the TCM under investigation. This review provides evidence and support for clinical treatment and novel drug research using TCM.