The Profile of Early Sedation Depth and Clinical Outcomes of Mechanically Ventilated Patients in Korea.

BACKGROUND: Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. METHODS: From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation-Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. RESULTS: Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death (P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence interval [CI], 0.55-0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% CI, 0.56-0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79-1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65-2.17; P = 0.582). CONCLUSION: In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.

High-Power Hydro-Actuators Fabricated from Biomimetic Carbon Nanotube Coiled Yarns with Fast Electrothermal Recovery.

Bioinspired yarn/fiber structured hydro-actuators have recently attracted significant attention. However, most water-driven mechanical actuators are unsatisfactory because of the slow recovery process and low full-time power density. A rapidly recoverable high-power hydro-actuator is reported by designing biomimetic carbon nanotube (CNT) yarns. The hydrophilic CNT (HCNT) coiled yarn was prepared by storing pre-twist into CNT sheets and subsequent electrochemical oxidation (ECO) treatment. The resulting yarn demonstrated structural stability even when one end was cut off without the possible loss of pre-stored twists. The HCNT coiled yarn actuators provided maximal contractile work of 863 J/kg at 11.8 MPa stress when driven by water. Moreover, the recovery time of electrically heated yarns at a direct current voltage of 5 V was 95% shorter than that of neat yarns without electric heating. Finally, the electrothermally recoverable hydro-actuators showed a high actuation frequency (0.17 Hz) and full-time power density (143.8 W/kg).

The Role of Interventional Radiology and Management of an Angiography Suite in the Treatment of COVID-19 Patients: Single-Center, 2-Year Experience.

Background and Objectives: Hospital angiography suites with negative-pressure ventilation facilities are challenging to equip. During the COVID-19 pandemic, we aimed to introduce interventional radiology procedures performed on COVID-19 patients and understand management of the angiography suite without a negative-pressure ventilation facility before and after the procedures to prevent the spread of infection. Materials and Methods: Between December 2020 and November 2022, 52 COVID-19 patients underwent interventional radiology procedures in an angiography suite, where no negative-pressure ventilation facility was installed. During the procedure, all staff members wore full personal protection equipment, and after the procedure for the COVID-19-positive patient was completed, the angiography suite was disinfected and entry to the angiography suite was prohibited for 1-3 h. In this angiography suite, procedures for COVID-19 patients and non-COVID-19 patients were performed. Results: A total of 61 interventional radiology procedures were performed in 52 patients with COVID-19. Of 52 patients, 21 underwent procedures under intubation and mechanical ventilation. All procedures were performed according to the guidelines set by the Infection Control Committee of our hospital. No major or minor complications were associated with the procedures. There were no cases of infection among staff members or other non-COVID-19 patients related to procedures on COVID-19 patients. Conclusions: Interventional radiology can play an important role in solving the complications of COVID-19 and the problems caused by patients' underlying diseases. In addition, if accurate guidelines are followed, both COVID-19 and non-COVID-19 patients can undergo procedures in an angiography room without negative-pressure ventilation while preventing infection.

Vitamin D deficiency and mortality among critically ill surgical patients in an urban Korean hospital.

Critically ill patients in intensive care units (ICUs) are exposed to various risk factors for vitamin D deficiency. Vitamin D deficiency in extended-stay patients may result in decreased muscle mass and increased fat tissue, which may impair rehabilitation and recovery. Our study aimed to evaluate the degree of serum vitamin D deficiency in critically ill surgical patients and its association with clinical outcomes. Clinical data from 186 adult male (n = 121; 65.1%) and female (n = 65; 34.9%) patients hospitalized in surgical ICUs at Ajou University Hospital from April 2015 to September 2016 were retrospectively analyzed. All adult surgical patients between the age of 18 and 88 years were enrolled. The mean serum 25-hydroxyvitamin D (25[OH]D) level of all patients was 17.8 ng/mL. A total of 120 patients (64.5%) with serum 25(OH)D levels < 20 ng/mL were classified as the deficiency group. A prolonged hospital stay was observed among the deficiency group but was not statistically significant (p = 0.824). Serum 25(OH)D levels were significantly correlated with age but inversely correlated with Sequential Organ Failure Assessment (SOFA) score, selenium, triglycerides, and C-reactive protein levels. There was no significant difference in mortality rates between the group with a vitamin D injection and the group without a vitamin D injection (14.6% vs. 16.9%, p = 0.074). Vitamin D deficiency was common in surgical ICU patients; however, vitamin D levels were higher in older patients. In conclusion, vitamin D deficiency was inversely associated with the SOFA severity score (correlation coefficient -0.165, p = 0.024) but was not associated with the length of hospital or ICU stay and mortality.

Retrograde transvenous obliteration for the prevention of variceal rebleeding in patients with portal vein thrombosis: a multicenter study.

OBJECTIVES: To evaluate the effectiveness of retrograde transvenous obliteration (RTO) for the prevention of variceal rebleeding in cirrhotic patients with portal vein thrombosis (PVT). METHODS: Consecutive cirrhotic patients with PVT who underwent RTO for the prevention of variceal rebleeding between January 2002 and June 2019 were included in this multicenter retrospective study. The primary outcome measure was rebleeding. The secondary outcome measures were survival, other complications of portal hypertension, liver function, and PVT. RESULTS: Forty-five patients (mean age, 66.0 ± 10.6 years; mean Model for End-Stage Liver Disease (MELD) score, 13.9 ± 5.5) were included. The 1-year actuarial probability of remaining free of rebleeding was 92.8 ± 4.0%. The 6-week, 1-year, and 3-year actuarial probabilities of survival were 79.8 ± 6.0%, 48.8 ± 7.7%, and 46.1 ± 7.9%, respectively. MELD score (hazard ratio (HR), 1.09 (95% confidence interval (CI), 1.01-1.17); p = .013) and ascites (HR, 2.84 (95% CI, 1.24-6.55); p = .014) were identified as significant predictors of survival. The 1-year actuarial probabilities of remaining free of new or worsening ascites and esophageal varices were 81.2 ± 8.7% and 89.2 ± 6.0%, respectively. No patients had overt hepatic encephalopathy during follow-up. MELD score significantly increased by a mean of 3.8 (95% CI, 1.7-6.0) at 3 months (p = .001). PVT had improved in 32.0%, worsened in 12.0%, and remained unchanged in 56.0% of patients at 3 months. CONCLUSION: RTO may be effective for the prevention of variceal rebleeding in cirrhotic patients with PVT. KEY POINTS: • Retrograde transvenous obliteration may prevent variceal rebleeding in cirrhotic patients with portal vein thrombosis. • The risks of other complications of portal hypertension may not be high after retrograde transvenous obliteration in cirrhotic patients with portal vein thrombosis. • Portal vein thrombosis may improve in approximately one-third of cirrhotic patients within 3 months after retrograde transvenous obliteration.

First Organ Donation after Circulatory Death Following Withdrawal of Life-sustaining Treatment in Korea: a Case Report.

In February 2018, the Withdrawal of the Life-sustaining Treatment (WLST) Decision Act was legalized in Korea. Donation after circulatory death (DCD) after WLST was classified as DCD category III. We report the first case of successful organ donation after WLST in Korea. A 52-year-old male who experienced cerebral hemorrhage was a potential brain-dead donor with donation consent. During the first brain death examination, Babinski reflex was present, which disappeared two days later. Then, electroencephalography was performed five times at intervals of 2 to 3 days, according to the recommendation of a neurologist. The patient was transferred to the OR at 19:30 July 3, 2020. At 20:00, an intensive care unit specialist performed extubation and discontinued vasopressors. Oxygen saturation fell to < 70% in 1 minute, which signaled the beginning of functional warm ischemia. At 20:15, asystole was confirmed; after 5 minutes of "no-touch time," circulatory death was declared. Organ procurement surgery was initiated, with surgeons performing the recipient surgery ready in the adjacent OR. Through the first successful DCD case, we expected that DCD will be actively implemented in Korea, saving the lives of patient waiting for transplantation and resolving the imbalance between organ receipt and donation.

Organ donation from brain-dead pediatric donors in Korea: A 5-year data analysis (2013-2017).

In Korea, 2-4% of brain-dead organ donations are from donors <16 years of age. We aimed to identify the current status of and challenges in pediatric organ donation from brain-dead donors in Korea. We performed a retrospective analysis using data from KONOS between January 1, 2013, and December 31, 2017. Our research identified 107 pediatric donors aged <16 years, representing 4.4% of all donors in Korea between 2013 and 2017. The consent rate was higher in PDs than in adult donors (47.0% vs 44.9%). The most common cause of brain death in PDs was hypoxia (28.0%), followed by brain tumor and trauma, whereas that in ADs was brain hemorrhage/stroke (42.4%), followed by trauma and hypoxia (P < .001). In both groups, the kidney (PDs vs ADs: 75.7% vs 88.5%), liver (58.9% vs 46.2%), and heart (32.7% vs 29.7%) were the organs most commonly transplanted. However, pancreatic (PDs vs ADs: 30.0% vs 11.7%, P < .001) and small bowel transplantations (4.7% vs 0.2%, P < .001) were more common in PDs, whereas lung (7.5% vs 14.5%, P = .046) and corneal transplantations (14.0% vs 36.2%) were more common in ADs. Only a small proportion of organ donations in Korea are from PDs, but this rate has been maintained. Given the current status of brain-dead pediatric organ donation, a more active approach is required to bring about improvement.

Single-Center Pharmacokinetic Study and Simulation of a Low Meropenem Concentration in Brain-Dead Organ Donors.

Meropenem is an ultrabroad-spectrum antibiotic of the carbapenem family. In brain-dead organ donors, administration of standard meropenem dosages does not reach therapeutic levels. Our objectives were to determine the plasma concentration of meropenem after the administration of standard meropenem dose and to estimate an improved dosage regimen for these patients. One gram of meropenem was administered as a 1-h infusion every 8 h for 1 to 3 days, and blood samples were collected. The plasma concentration of meropenem was measured and subjected to pharmacokinetic analysis. Simcyp simulation was performed to predict the optimum plasma levels and dosage based on the patients' individual pharmacokinetic parameters. The maximum plasma concentration of meropenem was 3.29 µg/ml, which was lower than four times the MIC of 8 µg/ml. Although the mean creatinine clearance of patients was moderately low (67.5 ml/min), the apparent volume of distribution at steady state (Vss) and time-averaged total body clearance (CL) of meropenem were markedly elevated (4.97 liters/kg and 2.06 liters/h/kg, respectively), owing to massive fluid loading to decrease the high sodium levels and to treat shock or dehydration. The simulation revealed that dose and infusion time of meropenem should be increased based on patients' Vss and CL, and a loading dose is recommended to reach rapidly the target concentration. In conclusion, a standard meropenem regimen is insufficient to achieve optimal drug levels in brain-dead patients, and an increase in dose and extended or continuous infusion with intravenous bolus administration of a loading dose are recommended for these patients.

The blind pushing technique for peripherally inserted central catheter placement through brachial vein puncture.

OBJECTIVE: The objective of this study was to conduct a prospective clinical trial evaluating the technical feasibility and short-term clinical outcome of the blind pushing technique for placement of pretrimmed peripherally inserted central catheters (PICCs) through brachial vein access. METHODS: Patients requiring PICC placement at any of the three participating institutions were prospectively enrolled between January and December 2016. The review boards of all participating institutions approved this study, and informed consent was obtained from all patients. PICC placement was performed using the blind pushing technique and primary brachial vein access. The following data were collected from unified case report forms: access vein, obstacles during PICC advancement, procedure time, and postprocedural complications. RESULTS: During the 12-month study period, 1380 PICCs were placed in 1043 patients. Of these, 1092 PICCs placed in 837 patients were enrolled, with 834 PICCs (76%) and 258 PICCs (34%) placed through brachial vein and nonbrachial vein access, respectively. In both arms, obstacles were most commonly noted in the subclavian veins (n = 220) and axillary veins (n = 94). Successful puncture of the access vein was achieved at first try in 1028 PICCs (94%). The technical success rate was 99%, with 1055 PICCs (97%) placed within 120 seconds of procedure time and 1088 PICCs (99%) having the tip located at the ideal position. Follow-up Doppler ultrasound detected catheter-associated upper extremity deep venous thrombosis (UEDVT) for 18 PICCs in 16 patients and late symptomatic UEDVT for 16 PICCs in 16 patients (3.1%). Catheter-associated UEDVT was noted for 28 PICCs (82%) and 6 PICCs (18%) placed through brachial vein and nonbrachial vein access, respectively. The incidence of obstacles and the procedure time (<120 seconds) differed significantly between brachial vein and nonbrachial vein access (P = .001). There was no statistically significant difference between brachial vein and nonbrachial vein access in the incidence of UEDVT (odds ratio, 0.68; 95% confidence interval, 0.59-3.52; P = .22). CONCLUSIONS: The placement of pretrimmed PICCs by the blind pushing technique and primary brachial vein access is technically feasible and may represent an alternative to the conventional PICC placement technique, having low incidences of UEDVT and other complications, with no significant difference in outcomes between brachial vein and nonbrachial vein access.

Immunomodulatory effects of intraoperative dexmedetomidine on T helper 1, T helper 2, T helper 17 and regulatory T cells cytokine levels and their balance: a prospective, randomised, double-blind, dose-response clinical study.

BACKGROUND: The ratio of T helper 1 (Th1) to T helper 2 (Th2) as well as T helper 17 (Th17) to regulatory T cells (Treg) represents the state and direction of immune response. Recent studies demonstrated that dexmedetomidine reduced the secretion of inflammatory cytokines. We performed this study to investigate the effect of different doses of intraoperative dexmedetomidine on the expression of Th1, Th2, T17 and Treg cytokines and their ratios. METHODS: Seventy-five patients undergoing laparoscopic cholecystectomy were randomly separated into one of three groups: the full dose group (n = 25), in which dexmedetomidine was infused with a 1.0 µg/kg loading followed by an infusion of 0.5 µg/kg/min after anaesthetic induction, or the half dose group (n = 26), in which the dose was half of that of full dose group, or the saline group (n = 24) which was control. T cell cytokines were quantified by sandwich enzyme-linked immunoassay for blood samples taken after anaesthetic induction (T0), at the end of surgery (T1), and 60 min after surgery (T2). IFN-gamma/IL-4 and IL-17/IL-10, which represent the ratio of Th1/Th2 and Th17/Treg cytokines, respectively, were calculated as indices of immune cell levels based upon serum cytokines levels in place of direct measurements. C-reactive protein (CRP) concentrations were measured on the next day following surgery. RESULTS: The full dose group was associated with higher ratios of IFN-gamma/IL-4 than those of half dose group and control [10.1 vs. 1.9 at T1 (P = 0.041) compared with half dose group, and 10.1 vs. 0.2 at T1 (P = 0.031), 7.4 vs. 0.1 at T2 (P = 0.025) compared with control]. IL-17/IL-10 ratios were higher in the full dose group than those in control [4.2 vs. 0.6 at T1 (P = 0.013), 3.0 vs. 0.3 at T2 (P = 0.011)]. The CRP levels were lower in the dexmedetomidine-treated groups in a dose-dependent manner. CONCLUSIONS: Dexmedetomidine exhibits immunomodulatory effects, shifting the Th1/Th2 and T17/Treg cytokine balance toward Th1 and T17, respectively, in a dose-dependent pattern in patients with surgical and anaesthetic stress. TRIAL REGISTRATION: Clinical Research Information Service, Republic of Korea (CRIS); KCT0000503 ; Registration date: Aug 13, 2012.

Causes of Failure during the Management Process from Identification of Brain-Dead Potential Organ Donors to Actual Donation in Korea: a 5-Year Data Analysis (2012-2016).

BACKGROUND: This retrospective study analyzed the causes of failure in the management process from the identification of brain-dead potential organ donors to actual donation in Korea over the past 5 years. METHODS: Data of 8,120 potential brain deaths reported to the Korea Organ Donation Agency were used, including information received at the time of reporting, donation suitability evaluation performed by the coordinator after the report, and data obtained from interviews of hospital medical staff and the donor's family. RESULTS: From January 2012 to December 2016, the total number of brain-dead potential organ donors in Korea was 8,120, of which 2,348 (28.9%) underwent organ procurement surgery with designated recipients. While the number of transplant donors has increased over time, the ratio of transplant donors to medically suitable brain-dead donors has decreased. The common causes of donation failure included donation refusal (27.6%), non-brain death (15.5%), and incompatible donation (11.6%); 104 potential donors (7.8%) were unable to donate their organs because they were not pronounced brain dead. CONCLUSION: The rate of successful organ donation may be increased by analyzing the major causes of failure in the brain-dead organ donation management process and engaging in various efforts to prevent such failures.

Prevalence of Malnutrition in Hospitalized Patients: a Multicenter Cross-sectional Study.

BACKGROUND: Malnutrition is associated with many adverse clinical outcomes. The present study aimed to identify the prevalence of malnutrition in hospitalized patients in Korea, evaluate the association between malnutrition and clinical outcomes, and ascertain the risk factors of malnutrition. METHODS: A multicenter cross-sectional study was performed with 300 patients recruited from among the patients admitted in 25 hospitals on January 6, 2014. Nutritional status was assessed by using the Subjective Global Assessment (SGA). Demographic characteristics and underlying diseases were compared according to nutritional status. Logistic regression analysis was performed to identify the risk factors of malnutrition. Clinical outcomes such as rate of admission in intensive care units, length of hospital stay, and survival rate were evaluated. RESULTS: The prevalence of malnutrition in the hospitalized patients was 22.0%. Old age (≥ 70 years), admission for medical treatment or diagnostic work-up, and underlying pulmonary or oncological disease were associated with malnutrition. Old age and admission for medical treatment or diagnostic work-up were identified to be risk factors of malnutrition in the multivariate analysis. Patients with malnutrition had longer hospital stay (SGA A = 7.63 ± 6.03 days, B = 9.02 ± 9.96 days, and C = 12.18 ± 7.24 days, P = 0.018) and lower 90-day survival rate (SGA A = 97.9%, B = 90.7%, and C = 58.3%, P < 0.001). CONCLUSION: Malnutrition was common in hospitalized patients, and resulted in longer hospitalization and associated lower survival rate. The rate of malnutrition tended to be higher when the patient was older than 70 years old or hospitalized for medical treatment or diagnostic work-up compared to elective surgery.

Twistable and Stretchable Sandwich Structured Fiber for Wearable Sensors and Supercapacitors.

Twistable and stretchable fiber-based electrochemical devices having high performance are needed for future applications, including emerging wearable electronics. Weavable fiber redox supercapacitors and strain sensors are here introduced, which comprise a dielectric layer sandwiched between functionalized buckled carbon nanotube electrodes. On the macroscopic scale, the sandwiched core rubber of the fiber acts as a dielectric layer for capacitive strain sensing and as an elastomeric substrate that prevents electrical shorting and irreversible structural changes during severe mechanical deformations. On the microscopic scale, the buckled CNT electrodes effectively absorb tensile or shear stresses, providing an essentially constant electrical conductance. Consequently, the sandwich fibers provide the dual functions of (1) strain sensing, by generating approximately 115.7% and 26% capacitance changes during stretching (200%) and giant twist (1700 rad·m-1 or 270 turns·m-1), respectively, and (2) electrochemical energy storage, providing high linear and areal capacitances (2.38 mF·cm-1 and 11.88 mF·cm-2) and retention of more than 95% of initial energy storage capability under large mechanical deformations.

A General Approach to Preferential Formation of Active Fe-Nx Sites in Fe-N/C Electrocatalysts for Efficient Oxygen Reduction Reaction.

Iron-nitrogen on carbon (Fe-N/C) catalysts have emerged as promising nonprecious metal catalysts (NPMCs) for oxygen reduction reaction (ORR) in energy conversion and storage devices. It has been widely suggested that an active site structure for Fe-N/C catalysts contains Fe-Nx coordination. However, the preparation of high-performance Fe-N/C catalysts mostly involves a high-temperature pyrolysis step, which generates not only catalytically active Fe-Nx sites, but also less active large iron-based particles. Herein, we report a general "silica-protective-layer-assisted" approach that can preferentially generate the catalytically active Fe-Nx sites in Fe-N/C catalysts while suppressing the formation of large Fe-based particles. The catalyst preparation consisted of an adsorption of iron porphyrin precursor on carbon nanotube (CNT), silica layer overcoating, high-temperature pyrolysis, and silica layer etching, which yielded CNTs coated with thin layer of porphyrinic carbon (CNT/PC) catalysts. Temperature-controlled in situ X-ray absorption spectroscopy during the preparation of CNT/PC catalyst revealed the coordination of silica layer to stabilize the Fe-N4 sites. The CNT/PC catalyst contained higher density of active Fe-Nx sites compared to the CNT/PC prepared without silica coating. The CNT/PC showed very high ORR activity and excellent stability in alkaline media. Importantly, an alkaline anion exchange membrane fuel cell (AEMFC) with a CNT/PC-based cathode exhibited record high current and power densities among NPMC-based AEMFCs. In addition, a CNT/PC-based cathode exhibited a high volumetric current density of 320 A cm-3 in acidic proton exchange membrane fuel cell. We further demonstrated the generality of this synthetic strategy to other carbon supports.

DRESS syndrome and acute generalized exanthematous pustulosis induced by antituberculosis medications and moxifloxacin: case report
.

OBJECTIVE: To report a rare case of drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome caused by antituberculosis (TB) drugs, which progressed to acute generalized exanthematous pustulosis (AGEP) after moxifloxacin treatment. CASE SUMMARY: A 25-year-old female was hospitalized for dyspnea and dizziness. She had a history of TB and experienced rifampin-induced skin rash. She was treated for TB with moxifloxacin, isoniazid, ethambutol, and pyrazinamide. Upon admission, she had a fever of 39.2 °C, and aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, and eosinophil count increased during the first 10 days after admission. The patient had a rash all over the body with itching, pain, and a burning sensation. Diagnosis of DRESS syndrome was made. Immunoglobulin and prednisolone administration improved the DRESS symptoms. After the first DRESS syndrome diagnosis, anti-TB medications were changed to isoniazid, ethambutol, pyrazinamide, cycloserine, and streptomycin, which also caused a skin rash, itching, and elevated AST/ALT levels, and eosinophil count. Then, the anti-TB treatment was changed to cycloserine, streptomycin, ethionamide, and para-aminosalicylic acid. The rash and itching persisted and eosinophil count increased further. All TB medications were discontinued except streptomycin. Due to the flushing and a burning sensation by streptomycin at the injection site, it was replaced with moxifloxacin. The patient experienced erythematous pustules and patches on skin with desquamation, fissures, and swelling. Therefore, a diagnosis of moxifloxacin-induced AGEP was made. CONCLUSION: DRESS syndrome induced by anti-TB drugs developed in a 25-year-old woman with moxifloxacin-related subsequent AGEP.
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Electrically tunable microlens arrays based on polarization-independent optical phase of nano liquid crystal droplets dispersed in polymer matrix.

Electrically tunable focusing microlens arrays based on polarization independent optical phase of nano liquid crystal droplets dispersed in polymer matrix are demonstrated. Such an optical medium is optically isotropic which is so-called an optically isotropic liquid crystals (OILC). We not only discuss the optical theory of OILC, but also demonstrate polarization independent optical phase modulation based on the OILC. The experimental results and analytical discussion show that the optical phase of OILC microlens arrays results from mainly orientational birefringence which is much larger than the electric-field-induced birefringence (or Kerr effect). The response time of OILC microlens arrays is fast~5.3ms and the tunable focal length ranges from 3.4 mm to 3.8 mm. The potential applications are light field imaging systems, 3D integrating imaging systems and devices for augment reality.

Analysis of hemodynamics and impedance using bioelectrical impedance analysis in hypovolemic shock-induced swine model.

To treat hypovolemic shock, fluid infusion or blood transfusion is essential to address insufficient volume. Much controversy surrounds resuscitation in hypovolemic shock. We aimed to identify the ideal fluid combination for treating hypovolemic shock-induced swine model, analyzing bioelectrical impedance and hemodynamics. Fifteen female three-way crossbred pigs were divided into three different groups. The three resuscitation fluids were (1) balanced crystalloid, (2) balanced crystalloid + 5% dextrose water, and (3) balanced crystalloid + 20% albumin. The experiment was divided into three phases and conducted sequentially: (1) controlled hemorrhage (1 L bleeding, 60 min), (2) resuscitation phase 1 (1 L fluid infusion, 60 min), and (3) resuscitation phase 2 (1 L fluid infusion, 60 min). Bioelectrical impedance analysis was implemented with a segmental multifrequency bioelectrical impedance analyzer. A total of 61 impedance measurements were assessed for each pig at six different frequencies in five segments of the pig. Pulse rate (PR), mean arterial pressure (MAP), stroke volume (SV), and stroke volume variation (SVV) were measured using a minimally invasive hemodynamic monitoring device. The three-dimensional graph showed a curved pattern when infused with 1 L of balanced crystalloid + 1 L of 5% dextrose water and 1.6 L of balanced crystalloid + 400 ml of 20% albumin. The 1M impedance increased in all groups during the controlled hemorrhage, and continuously decreased from fluid infusion to the end of the experiment. Only balanced crystalloid + 20% albumin significantly restored MAP and SV to the same level as the start of the experiment after the end of fluid infusion. There were no significant differences in MAP and SV from the time of recovery to the initial value of 1M impedance to the end of fluid infusion in all groups. The change and the recovery of hemodynamic indices such as MAP and SV coincide with the change and the recovery of 1M impedance. Using balanced crystalloid mixed with 20% albumin in hypovolemic shock-induced swine model may be helpful in securing hemodynamic stability, compared with balanced crystalloid single administration.

Liver Transplantation from Brain-Dead Donors with Hepatitis B or C in South Korea: A 2014-2020 Korean Organ Transplantation Registry Data Analysis.

BACKGROUND According to the current guidelines for liver transplantation (LT) of brain-dead donors with hepatitis B or C virus (HBV or HCV) in Korea, grafts from hepatitis B surface antigen (HBsAg)(+) or HCV antibody (anti-HCV)(+) donors must be transplanted only to HBsAg(+) or anti-HCV(+) recipients, respectively. We aimed to determine the current status and outcomes of brain-dead donor LT with HBV or HCV in Korea. MATERIAL AND METHODS This retrospective observational study included all LTs from brain-dead donors in the Korean Organ Transplantation Registry between April 2014 and December 2020. According to donor hepatitis status, 24 HBV(+), 1 HCV(+), and 1010 HBV(-)/HCV(-) donors were included. RESULTS Baseline/final model for end-stage liver disease score (MELD) for HBV(+), HCV(+), and HBV(-)/HCV(-) were 22.4±9.3/27.8±7.8, 16/11, and 33.0±15.4/35.5±7.1, respectively. MELD score of HBV (+) were lower than those of HBV(-)/HCV(-) (P<0.01). Five-year graft and patient survival rates of HBV(+) and HBV(-)/HCV(-) recipients were 81.7%/85.6%, and 76.6%/76.7%, respectively (P=0.73 and P=0.038). One-year graft and patient survival rates of HCV (+) graft recipients were both 100%. CONCLUSIONS No differences in graft and patient survival rates between HBV(+) and HBV(-)/HCV(-) groups were observed. Although accumulating the results of transplants from HBV (+) or HCV(+) grafts to HBV(-) or HCV(-) recipients is not possible owing to domestic regulations, Korea should conditionally permit transplantations from HBV(+) or HCV(+) grafts to HBV(-) or HCV(-) recipients by considering the risks and benefits based on foreign studies. Thereafter, we can accumulate the data from Korea and analyze the outcomes.

Kidney Transplantation From Brain-Dead Donors With Hepatitis B or C in South Korea: A 2015 to 2020 Korean Organ Transplantation Registry Data Analysis.

BACKGROUND: According to the current Center for Korean Network for Organ Sharing guidelines for kidney transplantation from brain-dead donors with hepatitis B or C infection, organs from hepatitis B surface antigen-positive (HbsAg+) or anti-hepatitis C virus-positive (HCV+) donors can only be transplanted into HBsAg+ or anti-HCV+ recipients. We aimed to confirm the status and the outcomes of kidney transplantation from brain-dead donors with hepatitis B or C virus in Korea. METHODS: This retrospective study included all kidney transplantations from brain-dead donors in the Korean Organ Transplantation Registry database between January 2015 and June 2020, divided into 3 groups according to donor hepatitis status. Finally, kidney transplantations from 80 HBV+, 12 HCV+, and 2013 HBV-/HCV- donors were included. RESULTS: No statistically significant differences were observed in the recipient characteristics and the transplant outcomes except the waiting time (HBV+ to HBV-/HCV-, P < .001; HCV+ to HBV-/HCV-, P = .10; HBV+ to HCV+P = .95). Five-year graft survival rates of the HBV+, HCV+, and HBV-/HCV- recipients were 95%, 83%, and 85%, respectively (HBV+ to HCV+, P = .22; HCV+ to HBV-/HCV-, P = .81; HBV+ to HBV-/HCV-, P = .02). Five-year patient survival rates of the HBV+, HCV+, and HBV-/HCV- recipients were 95%, 100%, and 76%, respectively (HBV+ to HCV+, P = .61; HCV+ to HBV-/HCV-, P = .13; HBV+ to HBV-/HCV-, P < .001). CONCLUSION: HBV+/HCV+ brain-dead donor kidney transplantation outcomes were comparable to HBV-/HCV-. South Korea should consider conditionally permitting transplantation from HBV+ or HCV+ donors to HBV- or HCV- recipients to accumulate new data and conduct further studies.

Structurally Aligned Multifunctional Neural Probe (SAMP) Using Forest-Drawn CNT Sheet onto Thermally Drawn Polymer Fiber for Long-Term In Vivo Operation.

Neural probe engineering is a dynamic field, driving innovation in neuroscience and addressing scientific and medical demands. Recent advancements involve integrating nanomaterials to improve performance, aiming for sustained in vivo functionality. However, challenges persist due to size, stiffness, complexity, and manufacturing intricacies. To address these issues, a neural interface utilizing freestanding CNT-sheets drawn from CNT-forests integrated onto thermally drawn functional polymer fibers is proposed. This approach yields a device with structural alignment, resulting in exceptional electrical, mechanical, and electrochemical properties while retaining biocompatibility for prolonged periods of implantation. This Structurally Aligned Multifunctional neural Probe (SAMP) employing forest-drawn CNT sheets demonstrates in vivo capabilities in neural recording, neurotransmitter detection, and brain/spinal cord circuit manipulation via optogenetics, maintaining functionality for over a year post-implantation. The straightforward fabrication method's versatility, coupled with the device's functional reliability, underscores the significance of this technique in the next-generation carbon-based implants. Moreover, the device's longevity and multifunctionality position it as a promising platform for long-term neuroscience research.