Development of albumin monitoring system with hepatic hypoxia-on-a-chip.

Hypoxia plays an essential role in the pathogenesis of various liver diseases, and albumin is one of the important biomarkers secreted by the liver. In this study, we developed an albumin monitoring system composed of hepatic hypoxia-on-a-chip and an albumin sensor to study liver function change due to hypoxia. In hepatic hypoxia-on-a-chip, we vertically stack an oxygen-scavenging channel on a liver on a chip with a thin gas-permeable membrane in the middle. This unique design of the hepatic hypoxia-on-a-chip can help to induce hypoxia quickly, attaining <5% within 10 min. An electrochemical albumin sensor was fabricated based on the covalent immobilization of antibodies on the Au electrode to monitor albumin secreting function on the hepatic hypoxia-on-a-chip. Standard albumin samples spiked in PBS, and culture media were measured by the electrochemical impedance spectroscopy using the fabricated immunosensor. The LOD was calculated to be 10 ag/mL in both cases. Using the electrochemical albumin sensor, we measured albumin secretion in normoxia and hypoxia in the chips. The albumin concentration decreased to 27% after 24 h in hypoxia compared to normoxia. This response was consistent with physiological studies. With technical refinements, the present albumin monitoring system can be a powerful tool in studying hepatic hypoxia with real-time liver function monitoring.

Fluorescent-based biodegradable microneedle sensor array for tether-free continuous glucose monitoring with smartphone application.

Continuous glucose monitoring (CGM) allows patients with diabetes to manage critical disease effectively and autonomously and prevent exacerbation. A painless, wireless, compact, and minimally invasive device that can provide CGM is essential for monitoring the health conditions of freely moving patients with diabetes. Here, we propose a glucose-responsive fluorescence-based highly sensitive biodegradable microneedle CGM system. These ultrathin and ultralight microneedle sensor arrays continuously and precisely monitored glucose concentration in the interstitial fluid with minimally invasive, pain-free, wound-free, and skin inflammation-free outcomes at various locations and thicknesses of the skin. Bioresorbability in the body without a need for device removal after use was a key characteristic of the microneedle glucose sensor. We demonstrated the potential long-term use of the bioresorbable device by applying the tether-free CGM system, thus confirming the successful detection of glucose levels based on changes in fluorescence intensity. In addition, this microneedle glucose sensor with a user-friendly designed home diagnosis system using mobile applications and portable accessories offers an advance in CGM and its applicability to other bioresorbable, wearable, and implantable monitoring device technology.

Prediction of knee adduction moment using innovative instrumented insole and deep learning neural networks in healthy female individuals.

BACKGROUND: The knee adduction moment, a biomechanical risk factor of knee osteoarthritis, is typically measured in a gait laboratory with expensive equipment and inverse dynamics modeling software. We aimed to develop a framework for a portable knee adduction moment estimation for healthy female individuals using deep learning neural networks and custom instrumented insole and evaluated its accuracy compared to the standard inverse dynamics approach. METHODS: Feed-forward, convolutional, and recurrent neural networks were applied to the data extracted from five piezo-resistive force sensors attached to the insole of a shoe. RESULTS: All models predicted knee adduction moment variables during walking with high correlation coefficients, r > 0.72, and low root mean squared errors (RMSE), ranging from 0.5% to 1.2%. The convolutional neural network is the most accurate predictor of average knee adduction moment (r = 0.96; RMSE = 0.5%) followed by the recurrent and feed-forward neural networks. CONCLUSION: These findings and the methods presented in the current study are expected to facilitate a cost-effective clinical analysis of knee adduction moment for healthy female individuals and to facilitate future research on prediction of other biomechanical risk factors using similar methods.

Changes in the characteristics of trauma patients after the early COVID-19 outbreak: A retrospective study of a regional level 1 trauma center in Republic of Korea.

ABSTRACT: Gyeonggi-do (Gyeonggi province) has the second highest number of coronavirus disease (COVID-19) cases in the Republic of Korea after Seoul, with approximately 25% of the COVID-19 patients as of January 2021. Our center is a level I trauma center located in south Gyeonggi-do, and we aimed to evaluate whether the characteristics of trauma patients changed after the COVID-19 pandemic.We retrospectively reviewed the trauma patients registered with the Korea Trauma Database of the Center from February 2019 to January 2021. The patients were dichotomized into pre-coronavirus disease (pre-COVID) and coronavirus disease (COVID) groups, and their trauma volumes, injury characteristics, intentionality, and outcomes were compared.A total of 2628 and 2636 patients were included in the pre-COVID and COVID groups, respectively. During the COVID-19 period, motorcycle accidents, bicycle accidents, and penetrating injury cases increased, and pedestrian traffic accidents, slips, and injury by machines decreased. The average daily number of patients in the COVID group was lower in March (5.6 ±â€Š2.6/day vs 7.2 ±â€Š2.4/day, P = .014) and higher in September (9.9 ±â€Š3.2/day vs 7.7 ±â€Š2.0/day, P = .003) compared to the pre-COVID group. The COVID group also had a higher ratio of direct admissions (67.5% vs 57.2%, P < .001), proportion of suicidal patients (4.1% vs 2.7%, P = .005), and injury severity scores (14 [9-22] vs 12 [4-22], P < .001) than the pre-COVID group. The overall mortality (4.7% vs 4.9%, P = .670) and intensive care unit length of stay (2 [0-3] days vs 2 [0-4] days, P = .153) was not different between the 2 groups.Although the total number of patients did not change, the COVID-19 pandemic affected the number of monthly admissions and the injury mechanisms changed. More severely injured patients were admitted directly to the trauma center.

Association of the Magnitude of Nurses With the Use of Health Information Exchanges: Analyzing the National Health Insurance Claim Data of Hospitals and Clinics in Korea.

BACKGROUND: Many features of health care organizations (HCOs) have been identified to be associated with health information exchange (HIE), but subcategories of organizational factors focusing on nurse workforces still need to be identified. The objective of this study is to investigate the association of number of nurses with HIE use in Korea. METHODS: This study had a retrospective study design and used health insurance claim data from June 1, 2016 to June 30, 2018. The unit of analysis was the HCO, and any health insurance claims having HIE were counted by HCO. There were a total of 1490 HCOs having any HIE and 24 026 HCOs not having HIE. For statistical analysis, two-part model was used: logistic regression for HIE participation and the generalized linear model for the volume of HIE use. RESULTS: HIE was used by 44.6% of general hospitals, and 8.6% and 5.3% of small hospitals and clinics, respectively. Both HIE use and its volume were significantly positively associated with nurse variables. The use of HIE was significantly positively associated with nurse-to-bed ratio in general hospitals (OR 1.028; 1.016 to 1.041) and in small hospitals (OR 1.021; 1.016 to 1.027), and with the number of nurses (OR 1.041; 1.028 to 1.054) in clinics (P<.001). The volume of HIE use was also positively associated with nurse-to-bed ratio in general hospitals (OR 1.010; 1.004 to 1.017) and in small hospitals (OR 1.014; 1.006 to 1.022), and with the number of nurses (OR 1.055; 1.037 to 1.073) in clinics (P<.01). CONCLUSION: This study found that there was a low rate of HIE use in small hospitals and clinics. The number of nurses was critically associated with the use of HIE and the volume of HIE claims. HIE policy makers need to be aware of this factor in seeking to accelerate HIE.

Epitaxial Growth of Diamond-Shaped Au1/2Ag1/2CN Nanocrystals on Graphene.

Epitaxial synthesis of inorganic nanomaterials on pristine 2D materials is of interest in the development of nanostructured devices and nanocomposite materials, but is quite difficult because pristine surfaces of 2D materials are chemically inert. Previous studies found a few exceptions including AuCN, AgCN, CuCN, and Cu0.5Au0.5CN, which can be preferentially synthesized and epitaxially aligned onto various 2D materials. Here, we discover that Au1/2Ag1/2CN forms diamond-shaped nanocrystals epitaxially grown on pristine graphene surfaces. The nanocrystals synthesized by a simple drop-casting method are crystallographically aligned to lattice structures of the underlying graphene. Our experimental investigations on 3D structures and the synthesis conditions of the nanocrystals imply that the rhombic 2D geometries originate from different growth rates depending on orientations along and perpendicular to 1D molecular chains of Au1/2Ag1/2CN. We also perform in situ TEM observations showing that Au1/2Ag1/2CN nanocrystals are decomposed to Au and Ag alloy nanocrystals under electron beam irradiation. Our experimental results provide an additional example of 1D cyanide chain families that form ordered nanocrystals epitaxially aligned on 2D materials, and reveal basic physical characteristics of this rarely investigated nanomaterial.

Batteryless, Miniaturized Implantable Glucose Sensor Using a Fluorescent Hydrogel.

We propose a biomedical sensor system for continuous monitoring of glucose concentration. Despite recent advances in implantable biomedical devices, mm sized devices have yet to be developed due to the power limitation of the device in a tissue. We here present a mm sized wireless system with backscattered frequency-modulation communication that enables a low-power operation to read the glucose level from a fluorescent hydrogel sensor. The configuration of the reader structure is optimized for an efficient wireless power transfer and data communication, miniaturizing the entire implantable device to 3 × 6 mm 2 size. The operation distance between the reader and the implantable device reaches 2 mm with a transmission power of 33 dBm. We demonstrate that the frequency of backscattered signals changes according to the light intensity of the fluorescent glucose sensor. We envision that the present wireless interface can be applied to other fluorescence-based biosensors to make them highly comfortable, biocompatible, and stable within a body.

Janus Hydrogel Microbeads for Glucose Sensing with pH Calibration.

We present fluorescent Janus hydrogel microbeads for continuous glucose sensing with pH calibration. The Janus hydrogel microbeads, that consist of fluorescent glucose and pH sensors, were fabricated with a UV-assisted centrifugal microfluidic device. The microbead can calibrate the pH values of its surroundings and enables accurate measurements of glucose within various pH conditions. As a proof of concept, we succeeded in obtaining the accurate value of glucose concentration in a body-fluid-like sample solution. We believe that our fluorescent microbeads, with pH calibration capability, could be applied to fully implantable sensors for continuous glucose monitoring.

Predicting Functional Outcome Based on Linked Data After Acute Ischemic Stroke: S-SMART Score.

Prediction of outcome after stroke may help clinicians provide effective management and plan long-term care. We aimed to develop and validate a score for predicting good functional outcome available for hospitals after ischemic stroke using linked data. A total of 22,005 patients with acute ischemic stroke from the Clinical Research Center for Stroke Registry between July 2007 and December 2014 were included in the derivation group. We assessed functional outcomes using a modified Rankin scale (mRS) score at 3 months after ischemic stroke. We identified predictors related to good 3-month outcome (mRS score ≤ 2) and developed a score. External validations (geographic and temporal validations) of the developed model were performed. The prediction model performance was assessed using the area under the receiver operating characteristic curve (AUC) and the calibration test. Stroke severity, sex, stroke mechanism, age, pre-stroke mRS, and thrombolysis/thrombectomy treatment were identified as predictors for 3-month good functional outcomes in the S-SMART score (total 34 points). Patients with higher S-SMART scores had an increased likelihood of a good outcome. The AUC of the prediction score was 0.805 (0.798-0.811) in the derivation group and 0.812 (0.795-0.830) in the geographic validation group for good functional outcome. The AUC of the model was 0.812 (0.771-0.854) for the temporal validation group. Moreover, they had good calibration. The S-SMART score is a valid and useful tool to predict good functional outcome following ischemic stroke. This prediction model may assist in the estimation of outcomes to determine care plans after stroke.

Effect of altered carrying angle on the medial-to-lateral activation ratio in the biceps brachii and triceps brachii.

[Purpose] The purpose of this research was to examine differences in muscle activity between the resting forearm position (RFP) and the straight forearm position (SFP) during upper arm strengthening exercises. [Participants and Methods] In total, 35 healthy college students were randomly sampled (18 males and 17 females). Surface electromyography data were collected from the medial and lateral sides of the biceps and triceps brachii muscles. [Results] The medial muscles showed greater activity during SFP versus RFP, but no difference in overall activation was found between the two positions. [Conclusion] Carrying angle less affected to biceps and triceps brachii muscles activation during upper arm strengthening exercises.

Transdermal water-in-oil nanocarriers of nitric oxide for triggering penile erection.

Men's sexual health can have significant effects on a man's self-esteem, sexual relationship and male reproductive functions. Although commercially available drugs (e.g., VIAGRA and CIALIS) show effective treatment of erectile dysfunction (ED), patients with severe ED fail to respond to these medicines. Topical nitric-oxide (NO) delivery to penis can be a painless, alternative solution with severe ED because NO triggers erection and diffuses to the trabecular arteries and smooth muscles in the penis. We here develop water-in-oil (W/O) nanoemulsions (NEs) that contain NO and can directly spread on the penis. We optimize NE formation conditions including hydrophilic-lipophilic balance (HLB) and ratio of oil, water and surfactants. Then, by spreading NEs on penis skin of intact middle aged dogs, we verify medication effects and safety of the NEs in vivo. The water-in-oil NEs can be a promising non-invasive medication for ED patients with low response to a phosphodiesterase type 5 (PDE5) inhibitor, thus increasing quality of life in the aging society.

Changes to the Korean Disaster Medical Assistance System After Numerous Multi-casualty Incidents in 2014 and 2015.

OBJECTIVE: A number of multiple-casualty incidents during 2014 and 2015 brought changes to Korea's disaster medical assistance system. We report these changes here. METHODS: Reports about these incidents, revisions to laws, and the government's revised medical disaster response guidelines were reviewed. RESULTS: The number of DMAT (Disaster Medical Assistance Team) staff members was reduced to 4 from 8, and the mobilization method changed. An emergency response manual was created that contains the main content of the DMAT, and there is now a DMAT training program to educate staff. The government created and launched a national 24-hour Disaster Emergency Medical Service Situation Room, and instead of the traditional wireless communications, mobile instant smart phone messaging has been added as a new means of communication. The number of disaster base hospitals has also been doubled. CONCLUSION: Although there are still limitations that need to be remedied, the changes to the current emergency medical assistance system are expected to improve the system's response capacity. (Disaster Med Public Health Preparedness. 2017;11:526-530).

[Missionary Medicine of Canadian Presbytery and Korean Doctors under Japanese Occupation--focusing Sung-jin and Ham-heung].

In East Asia during the second half of the 19th century, overseas mission work by Protestant churches thrived. Missionaries built schools and hospitals and effectively used them for evangelism. In the 20th century when Social Gospel Movement was expanding, medical work has been recognized as a significant mission service in and by itself. This article reviewed the construction and characteristics of missions work conducted by Canadian Presbytery; missionary doctors and Korean doctors who worked at the mission hospitals; why the missionary medical work had to stop; and career paths taken by Korean doctors upon liberation from Japanese occupation. The Canadian Presbytery missionaries, unlike other denomination missionaries, were rather critical of Imperial Japan, but supportive towards Koreans. This could have stemmed from the reflection of their own experience of once a colony of British Empire and also their value system that promotes egalitarian, democratic and progressive theology. The Sung-jin and Ham-heung Mission Bases were a community, interacting organically as a 'Triangle of Church, School and Hospital.' The missionaries mobilized the graduates from Christian schools and organized a Young Men's Christian Association (YMCA). Some of the graduates were trained to become medical doctors or assistants and worked at mission hospitals. Missionary doctors' approaches to balancing evangelism and medical practice varied. For example, Robert Grieson went through confusion and struggled to balance conflicting roles as a pastor for evangelism and also as a physician. Kate McMillan, on the other hand, had less burden for evangelism than Grieson, and focused on medical work by taking advantage of the opportunity that, as a woman, she can easily approach Korean women. Still another case was Florence Murray who practised evangelism within the hospital setting, and successfully carried out the role as a hospital administrator, going beyond 'women's work' as McMillan did. Korean doctors and assistants who worked at the mission hospitals had seen the spread of Protestantism in their youth; had received modern education; had experienced the fall of own country in 1910 and nationwide protest against Japan in 1919. The majority of them were graduates of Severance Medical College, the hub of missionary medicine at the time. After the resignation from the mission hospitals, 80 percent of them became self-employed general practitioners. The operations of the mission hospitals began to contract in 1930 due to tightened control by Imperial Japan. Shrine worship imposed on Christians caused internal conflict and division among missionaries and brought about changes in the form and contents of the mission organization. The incidence of the assault of Dr. Grieson brought about the dissolution of Sung-jin mission base and the interruption of the operation of Je-dong Hospital. As the Pacific War expanded, missionaries were driven out of Korea and returned home. In conclusion, the missions work by Canadian Presbytery missionaries had greatly impacted Protestantism in Korea. The characteristics of Canadian Presbytery were manifested in their support of Korean nationalism movement, openness for Social Gospel, and maintaining equal footing with Korean Christians. Specifically we note the influence of these characteristics in Chosun doctors who had worked in the mission hospitals. They operated their own hospitals or clinics in a manner similar to the mission hospitals by providing treatment for poor patients free of charge or for a nominal fee and treating the patients in a kind and humanistic way. After the 1945 Liberation, Korean doctors'career paths split into two directions. most of them defected to South Korea and chose the path to work as general practitioners. A few of them remained in North Korea and became educator of new doctors. It is meaningful that former doctors of Canadian missionary hosptal became dean of 2 medical colleges among 3 of all in early North Korea. This article does not cover the comparative analysis of the medical work by the missionaries of Canadian Presbytery and other denominations. It is desirable to include this analysis of the contents and the comparison in a future study of Korean doctors who participated in the mission hospitals, by denomination and by geographical region.

[Formation of medical education in North Korea: 1945-1948].

This study focuses on the formation of medical education in North Korea from 1945 to 1948 in terms of the centralization of medical education, and on the process and significance of the systemization of medical education. Doctors of the past trained under the Japanese colonial system lived and worked as liberalists. More than half of these doctors who were in North Korea defected to South Korea after the country was liberated. Thus the North Korean regime faced the urgent task of cultivating new doctors who would 'serve the state and people.' Since the autumn of 1945, right after national liberation, Local People's Committees organized and implemented medical education autonomously. Following the establishment of the Provisional People's Committee of North Korea, democratic reform was launched, leading to the centralized administration of education. Consequently, medical educational institutions were realigned, with some elevated to medical colleges and others shut down. The North Korean state criticised the liberalistic attitude of doctors and the bureaucratic style of health administration, and tried to reform their political consciousness through political inculcation programs. The state also grant doctors living and housing privileges, which show its endeavor to build 'state medicine'. By 1947, a medical education system was established in which the education administration was put in charge of training new doctors while the health administration was put in charge of nurturing and retraining health workers. In this way, the state was the principal agent that actively established a centralized administrative system in the process of the formation of medical education in North Korea following national liberation. Another agent was deeply involved in this process - the faculty that was directly in charge of educating the new doctors. Studying the medical faculty remains another research task for the future. By exploring how the knowledge, generational experience, socio-political consciousness and world views adopted by these teachers during the colonial era were manifested in their pedagogy after national liberation will shed more light on the 'prototype' of North Korean medical education.

Towards smart tattoos: implantable biosensors for continuous glucose monitoring.

Diabetes can strike at any age, from childhood to adulthood, and lasts a lifetime. Thus, it is important to find ways to increase the quality of life for diabetic patients through intensive, continuous care of blood glucose concentrations. Glucose biosensors that are implanted under the skin are promising for continuous glucose monitoring because they can constantly read blood glucose concentrations and signal a warning in case of hypo- or hyperglycemia. The demand for subcutaneous glucose biosensors has led to the development of many glucose-sensing principles and sensor designs. This Review covers the effort to develop subcutaneous glucose biosensors, including the glucose-sensing principles, and discusses their current status for in vivo monitoring. In addition, the Review examines the future prospects for intensive diabetes care.

Physicians' perspectives on social competency education in academic medicine.

PURPOSE: This study aims to explore the improvement of medical curriculums by examining the relationship between attributes of the Korean physicians and their needs for specialized departments and professionals for enhancing Korean physicians' social competence. METHODS: The uniqueness of this study is in its conduction a survey about the Korean physicians' needs of specialized departments and professionals for physicians' social competence or not, unlikely that previous studies focused on reviews. Subjects of this study are 288 physicians among the members of the Korean Society of Medical Education and The Korea Intern Resident Association. The hierarchical regression analyses are conducted. RESULTS: The authors present the results. First, the needs of specialized departments decline if physicians have ever majored on basic medical and learned professionalism ethics. Second, the older physicians are, the much more learned professionalism ethics and the needs of leadership competence physicians have, the necessities of specialized professionals are reduced. Finally, the physicians' needs of patient-oriented communication and sympathy of human in society as well as professionalism ethics increase recognitions of the importance of specialized professionals. CONCLUSION: These results show that strengthening systemic and educators' individual capacity for successful social competence curriculums is important.

Long-term in vivo glucose monitoring using fluorescent hydrogel fibers.

The use of fluorescence-based sensors holds great promise for continuous glucose monitoring (CGM) in vivo, allowing wireless transdermal transmission and long-lasting functionality in vivo. The ability to monitor glucose concentrations in vivo over the long term enables the sensors to be implanted and replaced less often, thereby bringing CGM closer to practical implementation. However, the full potential of long-term in vivo glucose monitoring has yet to be realized because current fluorescence-based sensors cannot remain at an implantation site and respond to blood glucose concentrations over an extended period. Here, we present a long-term in vivo glucose monitoring method using glucose-responsive fluorescent hydrogel fibers. We fabricated glucose-responsive fluorescent hydrogels in a fibrous structure because this structure enables the sensors to remain at the implantation site for a long period. Moreover, these fibers allow easy control of the amount of fluorescent sensors implanted, simply by cutting the fibers to the desired length, and facilitate sensor removal from the implantation site after use. We found that the polyethylene glycol (PEG)-bonded polyacrylamide (PAM) hydrogel fibers reduced inflammation compared with PAM hydrogel fibers, transdermally glowed, and continuously responded to blood glucose concentration changes for up to 140 days, showing their potential application for long-term in vivo continuous glucose monitoring.

Injectable hydrogel microbeads for fluorescence-based in vivo continuous glucose monitoring.

Fluorescent microbeads hold great promise for in vivo continuous glucose monitoring with wireless transdermal transmission and long-lasting activity. The full potential of fluorescent microbeads has yet to be realized due to insufficient intensity for transdermal transmission and material toxicity. This paper illustrates the highly-sensitive, biostable, long-lasting, and injectable fluorescent microbeads for in vivo continuous glucose monitoring. We synthesized a fluorescent monomer composed of glucose-recognition sites, a fluorogenic site, spacers, and polymerization sites. The spacers are designed to be long and hydrophilic for increasing opportunities to bind glucose molecules; consequently, the fluorescent monomers enable high-intensive responsiveness to glucose. We then fabricated injectable-sized fluorescent polyacrylamide hydrogel beads with high uniformity and high throughput. We found that our fluorescent beads provide sufficient intensity to transdermally monitor glucose concentrations in vivo. The fluorescence intensity successfully traced the blood glucose concentration fluctuation, indicating our method has potential uses in highly-sensitive and minimally invasive continuous blood glucose monitoring.