DIGITAL MICROFLUIDIC CHIP BASED ON DIRECT INK WRITING FOR NUCLEIC ACID MULTIPLEX PCR DETECTION

This study presents a facile route to fabricate a novel kind of digital microfluidic (DMF) chip via direct ink writing. The manufacture of this device does not rely on conventional microfabrication processes and cleanrooms, which makes it easy to prepare and low cost. By measuring the change of contact angle (CA) and droplet velocity, we proved that it could perform droplet manipulation like traditional DMF chips. In addition, after optimizing the chip structure, through a peripheral support circuit, polymerase chain reaction (PCR) reagents could be automatically partitioned and mixed on the chip. Furthermore, we realized the multi-target end-point fluorescence detection of SARS-CoV-2 RNA on this chip, showing promising potential for automatic nucleic acid tests.

[Preliminary clinical analysis of direct renin inhibitor aliskiren in the treatment of severe coronavirus disease 2019 patients with hypertension].

Objective: To explore the feasibility of direct renin inhibitor aliskiren for the treatment of severe or critical coronavirus disease 2019 (COVID-19) patients with hypertension. Methods: The antihypertensive effects and safety of aliskiren was retrospectively analyzed in three severe and one critical COVID-19 patients with hypertension. Results: Four patients, two males and two females, with an average age of 78 years (66-87 years), were referred to hospital mainly because of respiratory symptoms. Three were diagnosed by positive novel coronavirus 2019 (2019-nCoV) nucleic acid or antibody, and the critical patient with cardiac insufficiency was clinically determined. Two patients were treated with calcium channel antagonist (CCB), one with angiotensin converting enzyme inhibitor (ACEI), and one with angiotensin Ⅱ receptor antagonist (ARB). After admission, ACEI and ARB were discontinued, one patient with heart failure was treated by aliskiren combined with diuretic.Three patients were treated with aliskiren combined with CCB among whom two withdrew CCB due to low blood pressure after 1 to 2 weeks. Based on comprehensive treatment including antiviral and oxygenation treatment, blood pressure was satisfactorily controlled by aliskiren after three to four weeks without serious adverse events. All patients were finally discharged. Conclusion: Our preliminary clinical data shows that antihypertensive effect of aliskiren is satisfactory and safe for severe COVID-19 patients complicated with hypertension.