E ffective contact tracing is critical to controlling the spread of coronavirus disease (COVID-19) (1). South Korea adopted a rigorous contact-tracing program comprising traditional shoe-leather epidemiology and new methods to track contacts by linking large databases (global positioning system, credit card transactions, and closed-circuit television). We describe a nationwide COVID-19 contact tracing program in South Korea to guide evidence-based policy to mitigate the pandemic (2). The Study South Korea's public health system comprises a national-level governance (Korea Centers for Disease Control and Prevention), 17 regional governments, and 254 local public health centers. The first case of COVID-19 was identified on January 20, 2020; by May 13, a total of 10,962 cases had been reported.

No abstract

Transdermal drug delivery patches based on hydrogels are widely used for the transdermal delivery of diverse drugs. However, most hydrogels do not exhibit adequate adhesiveness to skin surface. Herein, tissue adhesive hydrogels consisting of polyacrylamide/polydopamine (PAM/PDA) hydrogels embedded with extra-large pore mesoporous silica nanoparticles (XL-MSNs) are proposed based on the synergy of cohesive and adhesive properties. The incorporation of XL-MSNs leads to enhanced strength and adhesiveness to skin tissue due to an increased cohesive property derived from molecular interactions between XL-MSNs and polymer chains. The application of XL-MSNs to the hydrogel-skin tissue interface leads to a further enhanced adhesiveness due to the adhesive gluing role of XL-MSNs on the interface. The optimized condition enables a 4.9-fold increase in adhesion energy on the porcine skin tissue, compared to the control PAM/PDA patch. Strong adhesion is achieved immediately after the hydrogel patch is attached onto the skin as well as the surfaces of other organs. Finally, transdermal drug delivery through porcine skin is demonstrated by using the hydrogel patch, with a model drug loaded in the XL-MSNs embedded in the patch. These observations indicate a simple but highly effective strategy for preparing a highly adhesive hydrogel patch for transdermal drug delivery.

Excessive reactive oxygen species (ROS) play a significant role in the pathogenesis of many eye diseases. Controlling oxidative stress by reducing the amount of ROS is a potential therapeutic strategy for the prevention and treatment of eye diseases, particularly ocular surface diseases. Ceria nanoparticles (CeNPs) have been investigated owing to their efficient ROS-scavenging properties. To overcome the disadvantages of eyedrop administration due to rapid elimination on the surface of the eye and to retain the intrinsic properties of contact lenses, we developed an ROS-scavenging water-soluble CeNP-embedded contact lens (CeNP-CL) for the prevention of ocular surface diseases. The intrinsic ROS-scavenging property of the CeNPs, which mimicked the activities of superoxide dismutase and catalase, was incorporated into polyhydroxyethyl methacrylate-based contact lenses. The CeNP-CL exhibited high transparency and physical properties comparable to those of a commercial contact lens, along with excellent extracellular ROS-scavenging properties. The viabilities of human conjunctival epithelial cells and human meibomian gland epithelial cells were significantly enhanced in the presence of CeNP-CLs, even in media with high H 2 O 2 contents (100 and 500 μM). Additionally, the wearing of CeNP-CLs on the eyes had a protective effect in a mouse model when 3% H 2 O 2 eyedrops were administered. These results indicate the salvaging effect of the CeNP-CL in a high-ROS environment on the ocular surface, which may be helpful for the treatment of ocular surface diseases.

The eye has many barriers with specific anatomies that make it difficult to deliver drugs to targeted ocular tissues, and topical administration using eye drops or ointments usually needs multiple instillations to maintain the drugs’ therapeutic concentration because of their low bioavailability. A drug-eluting contact lens is one of the more promising platforms for controllable ocular drug delivery, and, among various manufacturing methods for drug-eluting contact lenses, incorporation of novel polymeric vehicles with versatile features makes it possible to deliver the drugs in a sustained and extended manner. Using the diverse physicochemical properties of polymers for nanoparticles or implants that are selected according to the characteristics of drugs, enhancement of encapsulation efficiency and prolonged drug release are possible. Even though therapeutic contact lenses with polymeric vehicles allow us to achieve sustained ocular drug delivery, drug leaching during storage and distribution and the possibility of problems related to surface roughness due to the incorporated vehicles still need to be discussed before application in a real clinic. This review highlights the overall trends in methodology to develop therapeutic contact lenses with polymeric vehicles and discusses the limitations including comparison to cosmetically tinted soft contact lenses.

We report the first 7,755 patients with confirmed COVID-19 in Korea as of March 12 th , 2020. A total of 66 deaths have been recorded, giving a case fatality proportion of 0.9%. Older people, and those with comorbidities were at a higher risk of a fatal outcome. The highest number of cases of COVID-19 were in Daegu, followed by Gyeongbuk. This summary may help to understand the disease dynamics in the early phase of the COVID-19 outbreaks, and may therefore, guide future public health measures.

No abstract

Scurvy is very rare disease in industrialized societies. Nevertheless, it still exists in higher risk groups including economically disadvantaged populations with poor nutrition, such as the elderly and chronic alcoholics. The incidence of scurvy in the pediatric population is very low. This study reports a case of scurvy in a 5-year-old girl with cerebral palsy and developmental delay based on MRI findings.curvy results from a deficiency of ascorbic acid (vitamin C). A marked reduction in the occurrence of scurvy has occurred over the last 100 years due to improved knowledge about the pathophysiology and treatment of scurvy. However, the disease still exists even in industrialized countries (1, 2). Because scurvy is rare in modern society, reported magnetic resonance imaging (MRI) findings associated with scurvy are very rare (3). We report a case of scurvy in a 5-year-old girl with associated MRI findings. CASE REPORTA 5-year-old girl was presented with swelling of the left thigh, general weakness, poor oral intake, and a mild fever for two weeks. There was no evidence of petechiae, bruising, or history of trauma. The patient was diagnosed with cerebral palsy, severe developmental delay, generalized tonic clonic seizures, and thus was treated with long-term anticonvulsant medication. The patient had a history of poor oral intake and vomiting due to swallowing difficulty for more than 1 month.Upon physical examination, the patient's weight was below the third percentile for her age group. Moreover, the patient's left thigh was swollen and warm without erythema. No other remarkable findings were found. The laboratory data results were as follows: white blood cell count, 17,500/ L, neutrophil count, 79%, lymphocyte count, 14%, and platelet count, 528,000/ L. Furthermore, the erythrocyte sedimentation rate was 11 mm/hr, the C-reactive protein level was 6.05 mg/dL, and the hemoglobin (9.2 g/dL) was within the normal range.The radiographs of both knees showed osteopenia, which is a thick sclerotic metaphyseal line above a widened physis, and small beak-like excrescences at the metaphysis of both femora. In addition, a disruption of the alignment of the distal physis of the left femur was also noted (Fig. 1).An MRI of the left thigh performed on the first hospital day revealed diffuse bone marrow signal changes in the femoral shaft with large subperiosteal fluid collection and displacement of the distal epiphysis. The marrow changes appeared as heterogeneous high and low signal intensities on T1-weighted images and heterogeneous high