Preparation and response to COVID-19 outbreak in Singapore: A case report.

The COVID-19 pandemic has an overwhelming impact on the nursing profession. Nurses play a vital role before and during pandemics, with nurse leaders taking the lead in preparation for outbreaks. In response to an outbreak, early recognition and preparation for the increasing threat, managing staffing challenges together with the well-being of nurses are of utmost importance. Strategies to promote physical distancing while not compromising continuing nursing education and patient care are also essential. With prompt actions and coordinated efforts, risk of spreading the virus within the healthcare sector can be kept at the minimum. As nurses are in the frontline of healthcare, their confidence in being well-supported by the hospital should be maintained. This case report describes the preparation and response of the nurses in Singapore General Hospital to the COVID-19 outbreak in Singapore.

Cavitation-induced traumatic cerebral contusion and intracerebral hemorrhage in the rat brain by using an off-the-shelf clinical shockwave device.

Traumatic cerebral contusion and intracerebral hemorrhages (ICH) commonly result from traumatic brain injury and are associated with high morbidity and mortality rates. Current animal models require craniotomy and provide less control over injury severity. This study proposes a highly reproducible and controllable traumatic contusion and ICH model using non-invasive extracorporeal shockwaves (ESWs). Rat heads were exposed to ESWs generated by an off-the-shelf clinical device plus intravenous injection of microbubbles to enhance the cavitation effect for non-invasive induction of injury. Results indicate that injury severity can be effectively adjusted by using different ESW parameters. Moreover, the location or depth of injury can be purposefully determined by changing the focus of the concave ESW probe. Traumatic contusion and ICH were confirmed by H&E staining. Interestingly, the numbers of TUNEL-positive cells (apoptotic cell death) peaked one day after ESW exposure, while Iba1-positive cells (reactive microglia) and GFAP-positive cells (astrogliosis) respectively peaked seven and fourteen days after exposure. Cytokine assay showed significantly increased expressions of IL-1ß, IL-6, and TNF-α. The extent of brain edema was characterized with magnetic resonance imaging. Conclusively, the proposed non-invasive and highly reproducible preclinical model effectively simulates the mechanism of closed head injury and provides focused traumatic contusion and ICH.

Focused shockwave induced blood-brain barrier opening and transfection.

Despite extensive efforts in recent years, the blood-brain barrier (BBB) remains a significant obstacle for drug delivery. This study proposes using a clinical extracorporeal shockwave instrument to open the BBB, combined with a laser assisted bi-axial locating platform to achieve non-invasive, controllable-focus and reversible BBB opening in the brains of rats. Under shockwave treatment with an intensity level of 5 (P-9.79 MPa, energy flux density (EFD) 0.21 mJ/mm2) and a pulse repetition frequency of 5 Hz, the BBB could be opened after 50 shocks without the use of an ultrasound contrast agent. With the proposed method, the BBB opening can be precisely controlled in terms of depth, size and location. Moreover, a shockwave based gene transfection was demonstrated using a luciferase gene.