Epidemiological Study on Korean Gallstone Disease (A Nationwide Cooperative Study)

To clarify the epidemiological characteristicsof gallstone disease in Korea and to evaluate thechronological changes in gallstone disease, the authorsperformed this first prospective nationwide cooperative study. The subjects were 1263 gallstonepatients who were admitted at 19 hospitals in Korea fromFebruary to July 1997. Questionnaires were recorded on1263 patients and gallstones were harvested from 1133 patients. The proportion of patients withgallbladder (GB), common bile duct (CBD), andintrahepatic duct (IHD) stones among total gallstonepatients was 64.0%, 21.9%, and 14.1%, respectively. GBstones were categorized as cholesterol (58.1%), blackpigment (25.2%), and brown pigment (12.1%) stones. CBDstones were classified as brown pigment (76.1%),cholesterol (18.4%), and black pigment (3.5%) stones. IHD stones were classified as brown pigment(61.4%) and mixed (35.6%) stones. Intrahepatic mixedstones had mean cholesterol and bilirubin contents of63.4 ± 20.8% and 23.1 ± 9.9%,respectively. In contrast, IHD brown pigment stones had meancholesterol and bilirubin contents of 35.1 ±20.5% and 39.6 ± 17.4%, respectively. Our studyshowed that the type and composition of gallstones inKorea was somewhat different compared with those inthe West. This study also demonstrated that there havebeen chronological changes in the type and compositionof gallstones when compared with previous domestic data. Another nationwide cooperative study maybe needed to elucidate and confirm the changing patternof gallstone disease.     

Curing Reaction and Phase Change in a Liquid Crystalline Monomer

An epoxy monomer was cured in liquid crystalline phase with three different amines to form (LCT). The thermal transitions of the LCT were studied by differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXD) and polarized optical microscopy (POM). Different curing features are observed depending on the curing agent and reaction condition, which is related to the formation and development of LC phase during cure. An isoconversional analysis is used to characterize the cure process.     

Synthesis and Luminescent Properties of Blue Light Emitting Polymers Containing both Hole and Electron Transporting Units

Poly[(oxy‐4,4′‐octafluorobiphenyloxy)‐1,4‐phenylenevinylene‐2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene‐1,4‐phenylene], POFB‐MEH‐PPV, poly[(oxy‐4,4′‐octafluorobiphenyloxy)‐1,4‐phenylenevinylene‐9,9‐dihexyl‐2,7‐fluorenediylvinylene‐1,4‐phenylene], POFB‐PF, and poly[(oxy‐4,4′‐octafluorobiphenyloxy)‐1,4‐phenylenevinylene‐N‐ethylhexyl‐3,6‐carbazolevinylene‐1,4‐phenylene], POFB‐PK, were synthesized by the well‐known Wittig condensation polymerization. We incorporated the high electron affinity (octafluorobiphenyl) and hole‐transporting (carbazole, fluorene, and dialkoxyphenyl) units into the conjugated main chain. The conjugation lengths are limited to the blue‐emission region by ether linkage. The resulting polymers were completely soluble in common organic solvents such as chloroform, 1,2‐dichloroethane, and cyclohexanone, and exhibited good thermal stability up to 300°C. The synthesized polymers showed UV‐visible absorbance and photoluminescence (PL) in the ranges of 350–385 nm and 460–490 nm, respectively. The fluorene or carbazole containing POFB‐PF and POFB‐PK showed blue photoluminescence peaks at 470 and 460 nm, respectively. The single‐layer light‐emitting diode was fabricated in a configuration of ITO (indium‐tin oxide)/polymer/Al. Electroluminescence (EL) emission of POFB‐PF and POFB‐PK were shown at 475 and 458 nm, respectively, corresponding to the pure blue emissions. And, a dialkoxyphenyl containing POFB‐MEH‐PPV showed greenish blue light at 494 nm. But, LED devices from synthesized polymers showed poor device performance and high turn on voltage. So, we fabricated light‐emitting diodes (LEDs) from blend polymers composed of poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) and POFB‐MEH‐PPV (POFB‐PF or POFB‐PK) as the emitting layers. The EL emission maxima of each blend polymers were in the range of 573–591 nm, which indicates that the emission is mainly due to MEH‐PPV and POFB‐MEH‐PPV (POFB‐PF or POFB‐PK) contributes to the enhancement of the luminescence. And each blend polymers exhibited higher EL quantum efficiency compared with MEH‐PPV at the same current density.     

Fabrication of a Selective Sensor Amplification Probe Modified with Multi-Component Zn2SnO4/SnO2 Heterostructured Microparticles as a Robust Electrocatalyst for Electrochemical Detection of Antibacterial Drug Secnidazole

In this study, we synthesized heterostructured zinc stannate/tin oxide microparticles (ZTO/TO MPs) by a simple coprecipitation method and used them as an effective electrode material for the electrochemical detection of the antibacterial drug secnidazole (SCZ). The as-prepared ZTO/TO MPs were characterized by XRD, Raman, FE-SEM, HR-TEM, EDX, and XPS analyses. The physiochemical studies clearly proved that the fabricated ZTO/TO MPs were formed in a heterostructure phase without other impurities. A glassy carbon electrode modified with the synthesized ZTO/TO MPs showed an excellent and improved electrocatalytic activity in the electrochemical reduction of SCZ. Using differential pulse voltammetry (DPV), an impressive linear calibration range, extending from 0.01 to 193 μM, was observed, coupled with a detection limit of 0.0054 μM and a sensitivity of 0.055 μA/μM. In addition, the ZTO/TO MPs/GCE showed very good selectivity for the detection of SCZ in the presence of a number of biological, inorganic, and structurally related compounds. Finally, the ZTO/TO MPs/GCE was investigated for the analysis of SCZ in human blood serum samples. A very good recovery was obtained when spiking the blood serum with SCZ, highlighting the good applicability of the ZTO/TO MPs/GCE for the electrochemical analysis of SCZ in complex biological samples.     

Limited cryoablation reduces hospital stay and opioid consumption compared to thoracic epidural analgesia after minimally invasive repair of pectus excavatum

pain following minimally invasive repair of pectus excavatum (MIRPE) is a critical concern that leads to a prolonged hospital stay and high doses of opiates administered to the patients. This study aimed to evaluate the efficacy of intraoperative cryoanalgesia (cryoablation of the intercostal nerves) during MIRPE. We retrospectively analyzed the data of 64 patients who underwent MIRPE and received cryoanalgesia or epidural analgesia between January 2019 and January 2021. The oral morphine milligram equivalent (MME) was used to calculate the dosage of opioid agents. The median age was 15 years (range, 4–33 years). The median postoperative hospital stay was 4 days (range, 2–6 days), with a median oral MME consumption of 45 mg (ranging from 0 to 1360 mg). Cryoanalgesia was performed in 38 patients, and epidural analgesia was administered to the remaining 26 patients. The cryoanalgesia group had a significantly lesser pain score, shorter postoperative hospital stay and lower oral MME consumption than the epidural analgesia group (5 vs 2; P < .001, 3 days vs 5 days; P < .001, 19 mg vs 634 mg; P < .001). Cryoanalgesia appears to reduce postoperative hospital stay and opioid consumption compared with epidural analgesia. The outcomes of this study indicate that cryoanalgesia might be a safe and effective method for pain control following MIRPE.     

The association between coronary artery calcification and mean platelet volume in the general population

Patients with coronary artery calcification have an increased risk of coronary vascular events and mortality. Coronary artery calcification can be quantified using the coronary calcium score (CCS) from multi-detected row computed tomography (MDCT), and the score is proportionally related to the severity of atherosclerotic disease. Mean platelet volume (MPV) is gaining interest as a new independent cardiovascular risk factor. Accordingly, the aim of our study was to evaluate the relationship between CCS and MPV in the general population. A total of 2116 individuals were enrolled from a health promotion center between July 2007 and June 2010. Among them, 259 subjects were included in the final analysis. MDCT was used to measure CCS and CCS?>?1 was defined as the presence of coronary calcification. The MPV value was significantly higher in the coronary artery calcification group than in the control group. Multivariate analyses showed that MPV was positively associated with coronary calcification (OR, 1.61; 95% CI 1.02-2.55). In summary, there was a significant association between coronary artery calcification and MPV in the general population. Therefore, the detection of elevated MPV should alert clinicians to the coexistence of multiple underlying CVD risk factors warranting early evaluation and treatment.     

The Risk of Tuberculosis in Patients With Inflammatory Bowel Disease Treated With Vedolizumab or Ustekinumab in Korea

The present study investigated the risk of active tuberculosis in patients with inflammatory bowel disease (IBD) treated with vedolizumab or ustekinumab, in actual clinical settings in a country with an intermediate tuberculosis burden. The medical records of 238 patients with IBD who received vedolizumab or ustekinumab were retrospectively reviewed at a tertiary referral center in South Korea. All patients had ≥ 3 months of follow-up duration and underwent a latent tuberculosis infection screening test before initiation of the administration of these drugs. Of the 238 patients enrolled, 181 had Crohn’s disease, and 57 had ulcerative colitis. During the median 18.7 months of follow-up, active tuberculosis did not develop in any patient treated with vedolizumab or ustekinumab. Therefore, we concluded that the risk of tuberculosis appears to be low in patients with IBD treated with vedolizumab or ustekinumab in South Korea.