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Is our mental health at risk due to spending a significant amount of time online due to the COVID-19 pandemic? In the new era that we are living in, where we live a life that coexists with the virus, we are participating in video conferences held online rather than on-site in order to slow the spread of the virus. Video conferencing has become our necessity since March 2020, and is becoming a new standard, especially in the MICE industry. Recently, however, people who have excessively used video conference platforms are complaining of video conference fatigue, which is a new negative emotion such as stress, anxiety, and worry as well as general work fatigue. Therefore, this study focused on the mechanism of video conferencing in MICE, which is rapidly digitally converted by the virus, and the digital psychological factors of the participants. This study derived the quality attributes of video conferencing in MICE and empirically analyzed the relationship with digital psychological factors of the video conference participants, such as video conference fatigue, social presence, and flow. One hundred and thirty-eight valid questionnaires collected from participants of several international academic conferences held in EXCO, Daegu, Korea, from 23 to 28 May 2021, were analyzed. The main results are as follows. First, unlike general video conference fatigue, MICE video conference fatigue was not found to be related to the preceding and following variables. This is due to the characteristics of the MICE video conference and the expertise of the participants. Second, social presence was identified as an important variable in MICE video conferencing. Although media-mediated, the feeling of being present with the presenter and participants was found to affect the participants’ flow in the video conference. Third, in this study, the fun factor was identified as the most important video conference quality that can enhance the social presence of the video conference participants of MICEs.

This study aimed to grasp the structural path to watchers’ flow by applying watching motivation to multi-channel network (MCN), which is spreading as a new sports broadcasting medium and to emphasize the role of interaction in MCN. A survey for the MCN users over the age of 19 participating in sports contents was conducted. Results showed that among watching motivation factors fun, host appeal, and content appeal had significant positive effects on interaction in sports broadcasting of MCN. Interaction was also found to have a positive effect on watchers’ flow. In the relationship between watching motivation and watchers’ flow, it was shown that fun, host appeal, and content appeal had significant positive effects on watchers’ flow by a partial mediating effect of interaction. The watchers’ flow through interaction is expected to result in sustainable participation behaviors in sports broadcasting of MCN.

This study attempts to contribute to improving the life of the elderly by empirically analyzing the factors affecting the psychological well-being of active seniors in the ‘With COVID-19’ era. To this end, the relationship between psychological well-being, health concern, and perceived risk of COVID-19 was verified for active seniors in Korea who enjoy camping. Two hundred and sixty-four valid questionnaires collected from active senior participants of “The Korea Camping Fair 2022” held in EXCO, Daegu, Korea, from 29 April to 1 May 2022, were analyzed. The main results were as follows. The health and psychological well-being of active seniors were higher than the normal level, and the perceived risk of COVID-19 was lower than the normal level. It was found that the health of active seniors had a positive effect on their psychological well-being. The perceived risk of COVID-19 was found to moderate the effect of health concern on psychological well-being. In conclusion, in order to improve the psychological well-being of active seniors, active leisure activities of the elderly are essential even in the COVID-19 situation, and various measures are needed to increase health. Not only this, but also, importantly, accurate information sharing on COVID-19 should be premised.

A personal watercraft (PWC) is a vessel that uses an inboard motor powering a water jet pump as a source of power and is operated by a person sitting, standing, or kneeling. Maneuvering a PWC is different from operating a motor vehicle or boat. An obstacle cannot be avoided by slowing down and turning the watercraft, throttle power is required to turn or maneuver the PWC. The watercraft stops only by drifting or turning sharply. The study examined sixty court decisions published in LexisNexis databases of the United States over the last decade. Cases included individuals injured while operating a PWC as a driver, passenger, or as a result of contact with a watercraft. A content analysis identified items to be used in the study. Crosstab and logistic regression analyses were used to identify demographic information and the characteristics of those who succeeded in a court of law. One-third of the cases were successful, adults, males, and the party who sustained a severe injury were more successful in a court of law with the exception of the statistically significant factors (high risk maneuvers and sharp turns). Among the additional results, we should be aware that insurance companies may not pay, additionally, it is unwise to loan a PWC to a female who has no experience.

COVID-19 has shifted people’s activities from the real world to the virtual world in many fields, such as conferences, shopping, education, and more. In the field of MICE, however, exhibitions have been held steadily since the second half of 2020 in the form of on-site exhibitions. The exhibition organizers and related authorities have tried to attract exhibitors and visitors to the exhibition hall by providing exhibition quarantine services. Moreover, despite various perceived risks during the COVID-19 period, exhibition visitors continue to visit the exhibition. This study, therefore, paid attention to the psychological factors of visitors who consistently visit on-site exhibitions even during the pandemic. In addition to the perceived risks, this study tried to examine the quality of exhibition quarantine services and switching intention of visitors, and to analyze the relationships between them. A survey of 167 people who visited the camping exhibition and well-food exhibition held in June 2021 found that they would not visit the exhibition due to the functional and financial risk of the exhibition rather than the risk of the virus. On the other hand, it was found that visitors who felt the social risk of COVID-19 valued the quality of exhibition quarantine service. Furthermore, the study found that the quarantine service quality lowered switching intention. Therefore, the study suggests that exhibition organizers should think about ways to strengthen the most essential characteristics of on-site exhibitions along with appropriate quarantine measures to induce steady visits even during the pandemic.

Background Recently, the human common salivary protein 1 (CSP1) was identified as an ortholog of the Demilune cell and parotid protein of mouse. However, its function remains to be determined. Here, we show that the serum CSP1 concentration of diabetes mellitus (DM) patients is much higher than that of healthy controls. Methods Recombinant human CSP1 was expressed as a Glutathione-S-transferase (GST)-tagged protein, and the purified fusion protein was used as an immunogen to generate monoclonal antibody (mAb) to CSP1. The produced mAb was tested as a probe in Western blotting of human saliva and in immunohistochemistry of various human tissues. The serum CSP1 levels of 31 DM patients and 38 normal adults were quantified by a house-fabricated CSP1 sandwich enzyme-linked immunosorbent assay (ELISA) system. Results Immunoblot analysis by mAb-hCSP1#4 showed that CSP1 in human saliva exists in a 27 kDa glycosylated form. Among the various human tissues tested, the salivary gland was the only tissue stained with mAb-hCSP1#4 by immunohistochemistry. Quantification of serum CSP1 concentration by CSP1 ELISA showed that the median values (25th–75th percentile) of DM patients and healthy adults were 22.2 (15.8–28.2) and 3.2 (0–11.4), respectively. Student's t-test results indicated that there was a statistically significant difference between the two groups (P

This study was performed to produce a strong antibody against repeated peptides for a specific region of an antigen. Nine amino acids at C-terminal from human brain β-tubulin III were selected as a target sequence since it is well known for a high conservancy of sequence and resistance to antibody production. The synthetic oligonucleotides had six bases (5′-CGAC—GT-3′, 5′-TC—CAGC-3′) appended at each end and were repeatedly linked and directly joined by ligase in the presence of restriction enzymes (AccI, AvaI) to allow for the construction of head-to-tail repeats. Ligated oligonucleotides containing more than 10-unit repeats were eluted from agarose gels and cloned into the AccI site of a modified pGEX expression vector. The cloned repeated target sequences were subsequently expressed in a bacterial system. A large amount of glutathione-S-transferase-fusion protein containing the unit repeats was purified by affinity chromatography on glutathione-agarose beads and injected into Balb/c mice to produce pol...

Background Myoglobin, creatine kinase-MB isoenzyme (CK-MB), and cardiac troponin I (cTnI) are cardiac biomarkers that are widely used to assist in the early and late diagnoses of acute myocardial infarction (AMI). Here, we present a clinically applicable fluorescence (FL) immunoassay for cardiac biomarkers. Methods Whole blood was mixed with FL-labeled detector Ab (antibody) and then loaded onto a capture Ab-immobilized strip in a test cartridge. The FL intensities at test and control line on the strip were obtained and converted in a laser FL scanner to determine the concentration of biomarker. The analytical performance of immunoassay system was evaluated by linearity and imprecision tests. The comparability of the FL immunoassay method was examined with a reference method. Results FL intensities and the levels of myoglobin, CK-MB, and cTnI displayed good linearity and high correlations (r = 0.999, 0.998, and 0.989, respectively). The coefficient of variations (CVs) of imprecision for all cardiac biomarkers were less than 8% in both intra- and interassays. When the results from the developed method and bioMerieux VIDAS assay were analyzed by Bland–Altman plot and Passing–Bablok plot, the two assay methods were in good agreement. Conclusion The FL immunoassay system can provide a platform for point-of-care testing (POCT), and it is an easy, fast, and reliable method for the quantification of cardiac biomarkers.

Background D-dimer is a widely used biomarker for the initial clinical assessment of suspected deep vein thrombosis and pulmonary embolism. Here, we presented a new fluorescence (FL) D-dimer assay system, which was developed with a platform of point-of-care test (POCT) for clinical applications. Methods Whole blood was mixed with FL-labeled anti-D-dimer detector antibody, and then loaded onto a disposable cartridge. After 12 min of incubation, the FL intensity was acquired by scanning of test cartridge and converted as level of D-dimer in a laser FL scanner. The analytical performance of FL immunoassay was evaluated by linearity, recovery, and precision tests. The comparability of the developed assay was examined with automated reference methods. Results The FL assay system showed a good linearity, and the analytical mean recovery of control was 103% in a dynamic working range. The imprecision of intra- and inter-as-say of coefficient of variations from assay system was less than 8%. The developed FL assay system showed strong correlation with two automated reference assays, Vidas D-dimer (r = 0.973) and Stalia D-dimer (r = 0.971). Conclusion The new FL immunoassay for D-dimer is a user-friendly, precise, and reproducible platform of POCT in whole blood.

Background: Although alanine aminotransferase (ALT) is a widely used indicator of liver function, ALT enzymatic activity may not always reflect the degree of liver damage. Improved methods or approaches would be useful. Methods: Monoclonal antibodies (mAbs) to ALT were generated to develop a sandwich enzyme immunoassay system. We used an immunoassay to measure ALT mass concentration and a common biochemical analyzer to assay ALT enzymatic activity in serum samples from patients with liver diseases and healthy individuals. The results from the 2 methods were compared and analyzed by ROC curve analysis. Results: The ALT sandwich enzyme immunoassay system demonstrated reliable performance in linearity, recovery, and imprecision studies. The ALT activity assay exhibited a higher diagnostic accuracy in acute hepatitis (AH) patients, but the ALT immunoassay exhibited higher sensitivity and specificity in patients with chronic liver diseases. The areas under the ROC curve for ALT mass and enzymatic activity were 0.82 and 0.98, respectively, in AH, 0.99 and 0.52 in hepatocellular carcinoma (HCC), and 0.94 and 0.45 in liver cirrhosis (LC). Serum samples from HCC and LC patients had higher amounts of ALT–immunoglobulin complexes [median A450, 1.7 (interquartile range, 1.4–1.9)] than the other groups [1.3 (interquartile range, 0.9–1.6)]. Conclusions: Our analysis of sera from the HCC and LC patient groups revealed considerable amounts of immunologically active but catalytically inactive ALT. The amount of the ALT–immunoglobulin complex increased with the severity of the liver disease. The 2-site immunoassay method may be useful in the differential diagnosis of some causes of liver disease.

Microalbuminuria (MAU), defined as a urinary albumin excretion of 30–300 mg/day, indicates a high probability of renal damage and is an accepted predictor for the early diagnosis of nephropathy in diabetic patients (1)(2). In addition, MAU has diagnostic implications in pregnancy as a predictive marker of preeclampsia (3)(4) and may play a role in identifying high risk of developing complications from cardiovascular diseases even in nondiabetic patients (5)(6)(7). Dye-binding assays can measure serum albumin but are too insensitive for MAU testing, making immunochemical assays the most widely used MAU methods (8). These immunoassays include immunoturbidimetry, immunofluorescence, ELISA, RIA, and zone immunoelectrophoresis. Recently, Kessler and coworkers (9)(10) introduced a laser-induced fluorescence system coupled to an automated centrifugal analyzer as a nonimmunologic assay for urinary albumin. Their system was based on the probe Albumin Blue 670/580, which becomes highly fluorescent on binding to albumin. We report a fluorescence immunochromatography assay (ICA) for quantitative determination of albumin in urine. The assay system consists of an ICA test strip in a disposable cartridge, a fluorescently labeled detector, and a laser fluorescence reader. Basically, the assay system adopts the inherent simplicity of a lateral-flow ICA and uses a competitive immunoassay mode with a simple, one-step operation (11). Briefly, fluorescently labeled albumin in the detector buffer competes with albumin in the sample for binding to an anti-albumin antibody immobilized on the test strip matrix. The more albumin is in the sample, the less the fluorescently labeled albumin reacts with the anti-albumin antibody and, thus, the lower the accumulation of fluorescence in the test line of a test strip. We generated a monoclonal antibody against human albumin (Sigma A8763) as an immunogen and conducted immunizations, cell fusion, and screening of hybridoma cells according to a standard …

Alanine aminotransferase (ALT) has been regarded as one of the most sensitive indicators of hepatocellular damage. While ALT is widely used in the practice of medicine, few attempts have been made to develop biosensors applicable to the on-site diagnosis of liver diseases. In the hope of developing an immunosensor for measurement of ALT activity, we have generated monoclonal antibodies to human recombinant ALT and fabricated them for use in a sensor. The ALT immunosensor was composed of the followings: (1) anti-ALT antibody-immobilized outer membrane; (2) pyruvate oxidase-absorbed inner membrane; (3) a self assembled monolayer mediator-coated gold working electrode and an Ag/AgCl reference electrode. The chronoamperometric measurement of the immunosensor was performed with 40 microl of PBS containing substrates and ALT without a washing step in less than 5 min. The dynamic range of ALT immunosensor was presented as five orders of magnitude, ranging between 10 pg/ml and 1 microg/ml. The detection limit and the sensitivity were 10 pg/ml and 26.3 nA/(ng/ml), respectively. In the meantime, the enzyme sensor fabricated without anti-ALT antibody showed much poorer analytical values. The dynamic range, the detection limit, and the sensitivity were 10 ng/ml-100 microg/ml, 10 ng/ml and 11.4 nA/(ng/ml), respectively. The presented results indicated that the immunosensor system provided much better technical performance in all of the aspects evaluated than did the enzyme sensor without the immobilized-antibody.

Immunoassays have become indispensable tools and achieved great importance in scientific and medical research. However, typical immunoassays are time‐consuming and use complex, multi‐step procedures. In this study, we introduce a new immunoassay system for the quantification of several analytes at a time without any washing steps. It is comprised of a detector solution with fluorescence‐labeled antibodies and a test strip with immobilized capture antibodies. Using a micro‐array scanner, the antigen‐anti body complex was quantitatively determined by measuring the intensities of fluorescence on the capture lines or dots of nitrocellulose membrane. This method demonstrated its rapid quantitative determination of analytes without many processing steps as well as specific identification of multiple analytes in biological specimens.

BACKGROUND: Myoglobin, creatine kinase‐MB isoenzyme (CK‐MB), and cardiac troponin I (cTnI) are cardiac biomarkers that are widely used to assist in the early and late diagnoses of acute myocardial infarction (AMI). Here, we present a clinically applicable fluorescence (FL) immunoassay for cardiac biomarkers. METHODS: Whole blood was mixed with FL‐labeled detector Ab (antibody) and then loaded onto a capture Ab‐immobilized strip in a test cartridge. The FL intensities at test and control line on the strip were obtained and converted in a laser FL scanner to determine the concentration of biomarker. The analytical performance of immunoassay system was evaluated by linearity and imprecision tests. The comparability of the FL immunoassay method was examined with a reference method. RESULTS: FL intensities and the levels of myoglobin, CK‐MB, and cTnI displayed good linearity and high correlations (r = 0.999, 0.998, and 0.989, respectively). The coefficient of variations (CVs) of imprecision for all cardiac biomarkers were less than 8% in both intra‐ and interassays. When the results from the developed method and bioMerieux VIDAS assay were analyzed by Bland–Altman plot and Passing–Bablok plot, the two assay methods were in good agreement. CONCLUSION: The FL immunoassay system can provide a platform for point‐of‐care testing (POCT), and it is an easy, fast, and reliable method for the quantification of cardiac biomarkers.

We have developed a large-scale screen to identify genes expressed at different times during the life cycle of Saccharomyces cerevisiae and to determine the subcellular locations of many of the encoded gene products. Diploid yeast strains containing random lacZ insertions throughout the genome have been constructed by transformation with a mutagenized genomic library. Twenty-eight hundred transformants containing fusion genes expressed during vegetative growth and 55 transformants containing meiotically induced fusion genes have been identified. Based on the frequency of transformed strains producing beta-galactosidase, we estimate that 80-86% of the yeast genome (excluding the rDNA) contains open reading frames expressed in vegetative cells and that there are 93-135 meiotically induced genes. Indirect immunofluorescence analysis of 2373 strains carrying fusion genes expressed in vegetative cells has identified 245 fusion proteins that localize to discrete locations in the cell, including the nucleus, mitochondria, endoplasmic reticulum, cytoplasmic dots, spindle pole body, and microtubules. The DNA sequence adjacent to the lacZ gene has been determined for 91 vegetative fusion genes whose products have been localized and for 43 meiotically induced fusions. Although most fusions represent genes unidentified previously, many correspond to known genes, including some whose expression has not been studied previously and whose products have not been localized. For example, Sec21-beta-gal fusion proteins yield a Golgi-like staining pattern, Ty1-beta-gal fusion proteins localize to cytoplasmic dots, and the meiosis-specific Mek1/Mre4-beta-gal and Spo11-beta-gal fusion proteins reside in the nucleus. The phenotypes in haploid cells have been analyzed for 59 strains containing chromosomal fusion genes expressed during vegetative growth; 9 strains fail to form colonies indicating that the disrupted genes are essential. Fifteen additional strains display slow growth or are impaired for growth on specific media or in the presence of inhibitors. Of 39 meiotically induced fusion genes examined, 14 disruptions confer defects in spore formation or spore viability in homozygous diploids. Our results will allow researchers who identify a yeast gene to determine immediately whether that gene is expressed at a specific time during the life cycle and whether its gene product localizes to a specific subcellular location.

An NADPH-dependent succinic semialdehyde reductase has been purified from bovine brain by several chromatographic procedures. The preparation appeared homogeneous on SDS/PAGE. The enzyme is a monomeric protein with a molecular mass of 28 kDa. A number of properties of the bovine brain enzyme, such as substrate specificity, specific activity, molecular mass, optimum pH, amino acid composition, and kinetic parameters, have been determined and compared with those reported for preparations from other sources. The results indicate that the enzyme isolated from bovine brain in the present study is different from those reported for preparations from other sources. The inhibition kinetic patterns obtained when the products of the reaction or substrate analogs are used as inhibitor of the reaction catalyzed by the enzyme are consistent with an ordered sequential mechanism involving the formation of an intermediate ternary complex and in which NADPH is the first substrate to bind the enzyme.

Lysosomes are responsible for the degradation of macromolecules derived from the cell exterior by endocytosis, or from within the cell by autophagy. While our knowledge of the biosynthesis and targeting of lysosomal hydrolases is considerable, much less is known about the lysosomal membrane itself. To identify the lysosomal membrane proteins that mediate these functions, we have isolated lysosomes from amebae and injected them into mice to produce monoclonal antibodies (MAbs). We produced nine MAbs against Dictyostelium lysosomes from the batches of fused cells. Among them, three MAbs were specific to lysosomal membrane and gave a strong signal, and thus used in this study. The MAbs specifically reacted with a single protein band of 27 kd and stained a lysosome-like structure by immunofluorescence microscopy. To identify the antigen that the MAbs recognize, we processed differential centrifugation with whole-cell extract of Dictyostelium and traced p27 protein by activity assay of organelle marker enzyme. We showed that p27 is one component of the lysosomal system on the basis of comigration with a lysosomal marker enzyme. We also demonstrated that the 27-kd lysosomal protein is a tightly bound integral membrane protein by using a phase separation method of Triton X-114.

With the introduction of modern biochemical techniques, more than 50 enzymes have been developed for diagnostics in liver tests. Among the enzymes, aspartate aminotransferase (AST; EC 2.6.1.1; formerly known as GOT) was introduced in the mid-1950s and has remained the mainstay of enzyme diagnosis for liver disease for more than half a century (1). AST is widely distributed among human organs as cytosolic and mitochondrial isotypes (2). Increased activity of this enzyme is considered one of the most sensitive indicators of hepatocellular damage (3). Previously, several attempts were made to develop an immunoassay procedure for measuring AST mass rather than enzyme activity, but they are currently not used for the diagnosis of liver diseases (4)(5)(6)(7)(8). In this study, we generated monoclonal antibodies (mAbs) to AST and used them to develop a sandwich ELISA to measure the enzyme mass in sera. Because the amino acid sequences of the human and porcine enzymes are similar, we used porcine AST as an immunogen for the production of mAbs (9). The porcine enzyme is commercially available as a highly purified form in large quantities. Twenty hybridoma cells to porcine AST were initially screened by ELISA from several fusions, and four clones were selected for further characterization. To confirm the specificity of the mAbs to the human enzyme, we immunoblotted partially purified human enzyme and total proteins extracted from a human liver with the mAbs. The antibodies specifically recognized a single protein band of 45 kDa, which coincided well with the expected size of AST. To evaluate whether the mAbs recognized a cytosolic or a mitochondrial form of AST in human tissues, we prepared cytosolic …

The human immunodeficiency virus type 1 (HIV-1) Tat protein transduction domain (PTD), which contains a high proportion of arginine and lysine residues, is responsible for highly efficient protein transduction through the plasma membrane. To identify the role of the PTD sequence motif in transduction, various deletions and substitutions were introduced into the PTD. Tat–green fluorescent protein (GFP) fusion proteins, containing various lengths of the Tat PTD, were expressed and the extent of their transduction into mammalian cells was analysed by Western blot analysis and fluorescence microscopy. Deletion analysis of PTD mapped to a nine amino acid motif (residues 49–57: RKKRRQRRR) sufficient for transduction. Further deletion of this Tat basic domain either at the N terminus or at the C terminus significantly decreased transduction efficiency. The transduction efficiencies of GFPs fused to nine consecutive lysine (9Lys–GFP) or arginine (9Arg–GFP) residues were similar to that of Tat(49–57)–GFP. The transduced proteins localized to both the nucleus and the cytosol, as assessed by confocal microscopy and Western blot analysis of subcellular fractions from transduced cells. Thus, the availability of recombinant GFP fusion proteins facilitates the simple and specific identification of protein transduction mediated by these peptide sequences. The modified PTD sequences designed in this study may provide useful tools necessary for delivering therapeutic proteins/peptides into cells.