Determination of lysophosphatidylcholine using peroxidase-mimic PVP/PtRu nanozyme.

Lysophosphatidylcholine (LPC) can be used as a biomarker for diseases such as cancer, diabetes, atherosclerosis, and sepsis. In this study, we demonstrated the ability of nanozymes to displace the natural derived enzyme in enzyme-based assays for the measurement of LPC. Synthesized polyvinylpyrrolidone-stabilized platinum-ruthenium nanozymes (PVP/PtRu NZs) had a uniform size of 2.48 ± 0.24 nm and superb peroxidase-mimicking activity. We demonstrated that the nanozymes had high activity over a wide pH and temperature range and high stability after long-term storage. The LPC concentration could be accurately analyzed through the absorbance and fluorescence signals generated by the peroxidation reaction using the synthesized nanozyme with substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) and 10-acetyl-3,7-dihydroxyphenoxazine (Ampliflu™ Red). LPC at a concentration of 0-400 µM was used for the analysis, and the coefficient of determination (R2) was 0.977, and the limit of detection (LOD) was 23.1 µM by colorimetric assay. In the fluorometric assay, the R2 was 0.999, and the LOD was 8.97 µM. The spiked recovery values for the determination of LPC concentration in human serum samples were 102-115%. Based on these results, we declared that PVP/PtRu NZs had an ability comparable to that of the native enzyme horseradish peroxidase (HRP) in the enzyme-based LPC detection method.

Service Employees' Mindfulness and Job Crafting amid COVID-19: The Roles of Resilience, Organizational Health Climate, and Health-Oriented Leadership.

Due to changes in the work environment resulting from the COVID-19 pandemic, service employees' behavior, that proactively reshapes the content and meaning of work (i.e., job crafting), is increasingly important. We identified mindfulness as a key individual trait contributing to job crafting in the pandemic context. The purpose of our study was to examine the mediating effect of resilience on the relationship between mindfulness and job crafting, and the moderating effects of perceived organizational health climate and health-oriented leadership on the mindfulness-resilience relationship. We administered two-wave online surveys to 301 South Korean service employees after the onset of COVID-19 (January 20, 2020). Data for mindfulness, resilience, perceived organizational health climate, and health-oriented leadership were collected via participants' self-report in March, 2020. One month later (April, 2020), we obtained their self-ratings of job crafting. Results showed that resilience mediated the relationship between mindfulness and job crafting. The positive relationship between these two variables was more pronounced when perceived organizational health climate was high than when it was low. Perceived organizational health climate further moderated the indirect effect of mindfulness on job crafting through resilience.

Mesoporous platinum nanoparticles as a peroxidase mimic for the highly sensitive determination of C-reactive protein.

The generation of a mesoporous structure in platinum nanoparticles can effectively enhance physical and chemical properties. In this study, mesoporous platinum nanoparticles (MPNs) were synthesized by a soft template-mediated one-pot chemical method. To develop a mesoporous structure, Pluronic F-127 was employed. The Pluronic F-127 surfactant forms self-assembled micelles, and the micelles act as the pore-directing agents in the synthesis of nanoparticles. Scanning electron microscopy results revealed that the MPN had a uniform size of 70 nm on average and a distinct mesoporous structure. The development of a concave mesoporous structure on the surface of the MPNs can increase the surface area and facilitate the efficient transport of reactants. The synthesized MPNs exhibited peroxidase-like activity. Furthermore, the MPNs showed excellent catalytic efficiency compared to HRP, due to the high surface area derived from the presence of the mesoporous structure. The peroxidase-like MPNs were applied to the enzyme-linked immunosorbent assay (ELISA) of C-reactive protein (CRP). The MPN-based ELISA exhibited sensitive CRP detection in the range from 0.24 to 7.8 ng/mL with a detection limit of 0.13 ng/mL. Moreover, the recoveries of the CRP concentrations in spiked human serum were 98.6% and 102%. These results demonstrate that as a peroxidase mimic, the MPNs can replace the natural enzymes in conventional ELISA for sensitive CRP detection.

Au nanoparticle-hydrogel nanozyme-based colorimetric detection for on-site monitoring of mercury in river water.

A sensitive on-site mercury sensing platform was developed for simple and effective monitoring of mercury levels in the field. The simple and practical mercury detection system was designed by integrating an Au nanoparticle-PEG hydrogel block nanozyme (Au-HBNz) into a polymer film-based colorimetric device. Upon addition of Hg2+ ions, Au-HBNz exhibited excellent peroxidase-like activity, catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine into a blue-colored product, which has a maximum absorbance at 652 nm. The resulting color intensity change was evaluated using a smartphone for simple and rapid Hg2+ detection with a broad detection range (0.008-20 µg∙mL-1) and a linear concentration-response relationship (R2 = 0.96). The detection limit (1.10 ng∙mL-1) was lower than the maximum permissible Hg2+ levels in drinking water set by the World Health Organization (6 ng∙mL-1) and U.S. Environmental Protection Agency (2 ng∙mL-1). The recoveries of Hg2+ determination in river water by spiking Hg2+ samples ranged from 92 to 106%, which indicated high validity and applicability of the Hg2+ detection system for field measurements. Thus, the developed sensor enables highly selective and efficient real-time monitoring of Hg2+.

The effect of clonidine pretreatment on epidural resiniferatoxin in a neuropathic pain rat model.

Resiniferatoxin (RTX) is an ultrapotent synthetic TRPV1 (transient receptor potential vanilloid subtype 1) agonist with significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to thermal stimulus. Using a rat model of neuropathic pain, we evaluated the effect of pretreatment with clonidine-which has been shown to relieve intradermal capsaicin-induced hyperalgesia-on the initial hyperalgesic response and the thermal analgesic property of RTX. Thirty-six male rats were divided into 6 treatment groups (n=6 each):RTX 500 ng, RTX 1 µg, clonidine 20 µg (Cl), Cl＋RTX 500 ng, Cl＋RTX 1 µg, or normal saline 20 µL (control). We evaluated the short-term (180 min) and long-term (20 days) analgesic effects of RTX after thermal stimulation and mechanical stimulation. RTX had significant initial transient hyperalgesia followed by a prolonged analgesic effect in response to the thermal stimulus, but the RTX 500 ng and RTX 1 µg groups showed no initial short-term thermal hyperalgesic responses when pretreated with clonidine. The Cl＋RTX 1 µg rats' behavior scores indicated that they were more calm and comfortable compared to the RTX 1 µg rats. Even though we cannot precisely confirm that pretreatment with clonidine potentiates or adds to the analgesic effect of RTX, clonidine pretreatment with epidural RTX eliminated the initial RTX-associated hyperalgesic response and systemic toxicity in this neuropathic pain rat model.

THE ROLE OF CONSUMER VALUES AND SOCIO-DEMOGRAPHICS IN GREEN PRODUCT SATISFACTION: THE CASE OF HYBRID CARS.

This study investigated the relationship between consumer value and customer satisfaction, seeking a better understanding of the motivations underlying "green product" purchases. Based on the influence of demographic factors, it further explores the moderation effects of buyers' socio-demographics on the link between value and satisfaction. Data were collected through a mail survey of American hybrid car buyers. Consumer value, satisfaction, and socio-demographic information were measured, and the proposed relationships among them were tested using hierarchical multiple regression analysis. This study's findings reveal that values (i.e., functional and social) significantly impact hybrid satisfaction and that the effects vary by sex and age. This research provides insight into the motivations of green product purchases by incorporating important consumer characteristics.

Scaffold-free formation of a millimeter-scale multicellular spheroid with an internal cavity from magnetically levitated 3T3 cells that ingested iron oxide-containing microspheres.

This report describes fabrication of a millimeter-scale three-dimensional (3D) multicellular structure with a central cavity based on magnetic levitation of 3T3 cells that had ingested Fe3 O4 -containing microcapsules. Magnetically levitated cells initially formed a disc-shaped cell cluster at the air-medium interface and transformed into a spheroid (up to 2.8 mm in diameter) after 10-day incubation under a magnet. Hematoxylin-and-eosin-stained section revealed that an eosinophilic shell of cells enclosed a pale-staining core of the spheroid. Mitotic or elongated and aligned cells were found at the outer periphery of the shell, while Fe3 O4 deposits were distributed in the inner part of the shell. Surgical dissection indicated that the spheroid had a hollow interior filled with a fluid-state cell suspension. Accordingly, it was demonstrated that magnetically levitated 3T3 cells organized themselves into a tissue-like spheroid, resulting in core cell death. The spheroid can be used as a 3D tissue model and as building blocks that fused to form a more complicated structure.

Body-tanning attitudes among female college students.

This study investigated the attitudes of body-tanning behaviors: suntanning, tanning bed, tanning spray, and sunless tanning product use. Data collected from 208 female college students (M age = 19.8 yr., SD = 2.0; M weight = 63.3 kg, SD = 2.0; M height = 165.9 cm, SD = 8.1) online. The questionnaire comprised four constructs: appearance-based, health-based, and emotion-based tanning attitudes, and body-tanning behaviors. Both appearance-based and emotion-based pro-tanning attitudes were associated with significantly higher body-tanning behaviors. However, health-based pro-tanning attitudes did not significantly affect body-tanning behaviors. The results from both UV- and non-UV exposure-related tanning behaviors provide future intervention strategies, such as establishing a positive body image without a tan and identifying negative emotional consequences as a result of tanning.

The role of brand trust in male customers' relationship to luxury brands.

This study examined the role of brand trust in customers' luxury brand consumption behavior. Perceived value and brand satisfaction were presented within a framework as antecedents of brand trust, while brand loyalty and brand risk were presented as consequences. A face-to-face survey was administered to a sample (N = 400) of men between 25 and 54 years of age who had purchased luxury brand and non-luxury brand suits within the previous three months. The results showed the greater the hedonic value on brand satisfaction, the greater the influence of brand satisfaction on brand trust, and the greater was the effect of brand trust on brand loyalty for luxury brands as compared with non-luxury brands. Similar patterns are identified between luxury and non-luxury brands for the positive relationship between utilitarian value and brand satisfaction and the negative relationship between brand trust and brand risk.

Chromo-Fluorogenic Rhodamine-Based Amphiphilic Probe as a Selective and Sensitive Sensor for Intracellular Cu(I) in Living Cells.

Fluorescent probes are widely studied for metal ion detection because of their multiple favorable properties such as high sensitivity and selectivity, quick response, naked eye detection, and in situ monitoring. However, optical probes that can effectively detect the Cu(I) level in cell interiors are rare due to the difficulty associated with selectively and sensitively detecting this metal ion in a cell environment. Therefore, we designed and synthesized three water-soluble probes (1-3) with a 1,3,5-triazine core decorated by three substituents: a hydrophobic alkyl chain, a hydrophilic maltose, and a rhodamine B hydrazine fluorophore. Among the probes, probe 1, which has an octyl chain and a branched maltose group, was the most effective at sensing Cu+ in aqueous solution. Upon addition of Cu+, this probe showed a dramatic color change from colorless to pink in daylight and displayed an intense yellow fluorescence emission under 365 nm light. The limit of detection and dissociation constant (Kd) of this probe were 20 nM and 1.1 × 10-12 M, respectively, which are the lowest values reported to date. The two metal ion-binding sites and the aggregation-induced emission enhancement effect, endowed by the branched maltose group and the octyl chain, respectively, are responsible for the high sensitivity and selectivity of this probe for Cu+ detection, as demonstrated by 1H NMR, dynamic light scattering, and transmission electron microscopy studies. Furthermore, the probe successfully differentiated the Cu(I) level of cancer cells from that of the normal cells. Thus, the probe holds potential for real-time monitoring of Cu(I) level in biological samples and bioimaging of cancer cells.

The therapeutic efficacy of silver loaded rhenium disulfide nanoparticles as a photothermal agent for cancer eradication.

Cancer is a life-threatening disease when it is diagnosed at a late stage or treatment procedures fail. Inhibiting cancer cells in the tumor environment is a significant challenge for anticancer therapy. The photothermal effects of nanomaterials are being studied as a new cancer treatment. In this work, rhenium disulfide (ReS2) nanosheets were made by liquid exfoliation with gum arabic (GA) and coated with silver nanoparticles (AgNPs) to produce reactive oxygen species that destroy cancer cells. The synthesized AgNP-GA-ReS2 NPs were characterized using UV, DLS, SEM, TEM, and photothermal studies. According to the DLS findings, the NPs were about 216 nm in size and had a zeta potential of 76 mV. The TEM and SEM analyses revealed that the GA-ReS2 formed single-layered nanosheets on which the AgNPs were distributed. The photothermal effects of the AgNP-GA-ReS2 NPs at 50 µg/mL were tested with an 808 nm laser at 1.2 W cm-2, and they reached 55.8 °C after 5 min of laser irradiation. MBA-MB-231 cells were used to test the cytotoxicity of the newly designed AgNP-GA-ReS2 NPs with and without laser irradiation for 5 min. At 50 µg/mL, the AgNP-GA-ReS2 showed cytotoxicity, which was confirmed with calcein and EtBr staining. The DCFH-DA and flow cytometry analyses demonstrated that AgNP-GA-ReS2 nanosheets under NIR irradiation generated ROS with high anticancer activity, in addition to the photothermal effects.

In vitro cellular uptake of fibroin microspheres and its dependency on the cell cycle stage.

Cellular uptake of a protein microsphere was investigated in vitro. Fibroin microspheres with an average diameter of approximately 1 µm were prepared with Fluorescein isothiocyanate-dextran for the fluorescent core. Tomography, performed using confocal laser scanning microscopy, confirmed microsphere uptake into the cytoplasmic area of 3T3 cells. Flow cytometry showed that cellular uptake was proportional to the co-incubation time and the microsphere concentration. It also revealed that fibroin microspheres were internalised by 3T3 cells at different rates depending on the cell cycle stage. The following cell stages had higher concentrations of internalised microspheres: G(2)/M > S > G(0)/G(1), when using 0.1 mg of microspheres per 10(6) cells. The internalised microspheres per cell also increased in the same order of cell cycle stages when co-incubating cells with 1 mg of microspheres. These results provide information that can be used to develop fibroin microspheres for intracellular delivery of large cargos.

Daily relationships between job insecurity and emotional labor amid COVID-19: Mediation of ego depletion and moderation of off-job control and work-related smartphone use.

The economic recession in the service sector during the COVID-19 pandemic has jeopardized service employees' job security. While the daily fluctuations of perceived job insecurity may have implications for service employees' emotional labor, the day-to-day relationship between these two variables and their mediating and moderating mechanisms in the pandemic context remain unknown. To fill this gap, our research examined the day-level relationship between job insecurity perceptions, ego depletion, and emotional labor, as well as the moderating effects of overnight off-job control and work-related smartphone use. To assess these relationships, we conducted two daily studies during the COVID-19 pandemic. In study 1 (March-April 2020), 135 service employees responded to morning and evening online surveys for five workdays. In study 2 (June 2022), which administered morning and evening online surveys to 90 flight attendants for five workdays, work-related COVID-19 exposure risk was controlled in the analyses. The results of the two studies demonstrated that on a day when service employees perceived a high level of job insecurity, they felt ego-depleted, which, in turn, was associated with decreased deep acting and increased surface acting. Post hoc findings indicated a significant three-way interaction between off-job control, off-job work-related smartphone use, and daily job insecurity, such that the job insecurity-ego depletion-emotional labor was most pronounced when off-job control was low and off-job work-related smartphone use was high. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Struggling to Stay Engaged During Adversity: A Daily Investigation of Frontline Service Employees' Job Insecurity and the Moderating Role of Ethical Leader Behavior.

Drawing on conservation of resources theory, this study examined the moderating role of ethical leader behavior in the effects of daily perceived job insecurity on work outcomes the next day (i.e., work engagement and customer-directed helping) through occupational regret the next morning among frontline service employees working in adverse work situations (i.e., the coronavirus disease pandemic). Using experience sampling method, data were collected from 135 frontline service employees across five consecutive workdays. The results showed that daily perceived job insecurity had a negative indirect effect on work engagement and customer-directed helping the next day through (increased) occupational regret the next day in the morning. In addition, ethical leader behavior moderated the negative indirect effect of daily perceived job insecurity on next-day work engagement and customer-directed helping through next-morning occupational regret. Specifically, these negative effects were especially stronger among employees who had observed low levels of ethical leader behavior the previous day. The theoretical implications of the present findings for researchers and their practical implications for managers are discussed.

Ratiometric orange fluorescent and colorimetric highly sensitive imidazolium-bearing naphthoquinolinedione-based probes for CN- sensing in aqueous solutions and bio-samples.

The widespread use of cyanide (CN-) in industry results in contamination of various effluents such as drain, lake, and tap water, an imminent danger to the environment and human health. We prepared naphthoquinolinedione (cyclized; 1-5) and anthracenedione (un-cyclized) probes (6-7) for selective detection of CN-. The addition of CN- to the probe solutions (1-5) resulted in a color change from pale green to orange under 365 nm illumination. The nucleophilic addition of CN- to C2 of the imidazolium ring of the probes is responsible for selective CN- detection. Among all probes, 1 gave the lowest fluorescence-based LOD of 0.13 pM. In contrast, the un-cyclized probes (6 and 7) were substantially inferior to the cyclized counterparts (1 and 2, respectively) for detecting a trace amount of CN-. The notably low LOD displayed by probe 1 was maintained in the detection of CN- in real food samples, human fluids, and human brain cells. This is the first report studying imidazolium-bearing naphthoquinolinedione-based probes for CN- sensing in 100% water.

Multicomponent metal-organic framework nanocomposites for tumor-responsive synergistic therapy.

Targeted tumor therapy through tumor microenvironment (TME)-responsive nanoplatforms is an emerging treatment strategy used to enhance tumor-specificity to selectively kill cancer cells. Here, we introduce a nanosized zeolitic imidazolate framework-8 (ZIF-8) that simultaneously contains natural glucose oxidase (GOx) and Prussian blue nanoparticles (PBNPs) to construct multi-component metal-organic framework nanocomposites (denoted as ZIF@GOx@PBNPs), which possess cascade catalytic activity selectively within the TME. Once reaching a tumor site, GOx and PBNPs inside the nanocomposites are sequentially released and participate in the cascade catalytic reaction. In weak acidic TME, GOx, which effectively catalyzes the oxidation of intratumoral glucose to hydrogen peroxide (H2O2) and gluconic acid, not only initiates starvation therapy by cutting off the nutrition source for cancer cells but also produces the reactant for sequential Fenton reaction for chemodynamic therapy. Meanwhile, PBNPs, which are released from the ZIF-8 framework dissociated by acidified pH due to the produced gluconic acid, convert the generated H2O2 into harmful radicals to melanomas. In this way, the cascade catalytic reactions of ZIF@GOx@PBNPs enhance reactive oxygen species production and cause oxidative damage to DNA in cancer cells, resulting in remarkable inhibition of tumor growth. The tumor specificity is endowed by using the biomolecules overexpressed in TME as a "switch" to initiate the first catalytic reaction by GOx. Given the significant antitumor efficiency both in vitro and in vivo, ZIF@GOx@PBNPs could be applied as a promising therapeutic platform enabling starvation/chemodynamic synergism, high therapeutic efficiency, and minimal side effects.

Gum Arabic-mediated liquid exfoliation of transition metal dichalcogenides as photothermic anti-breast cancer candidates.

Transition metal dichalcogenides (TMDs) have gained considerable attention for a broad range of applications, including cancer therapy. Production of TMD nanosheets using liquid exfoliation provides an inexpensive and facile route to achieve high yields. In this study, we developed TMD nanosheets using gum arabic as an exfoliating and stabilizing agent. Different types of TMDs, including MoS2, WS2, MoSe2, and WSe2 nanosheets, were produced using gum arabic and were characterized physicochemically. The developed gum arabic TMD nanosheets exhibited a remarkable photothermal absorption capacity in the near-infrared (NIR) region (808 nm and 1 W⋅cm-2). The drug doxorubicin was loaded on the gum arabic-MoSe2 nanosheets (Dox-G-MoSe2), and the anticancer activity was evaluated using MDA-MB-231 cells and a water-soluble tetrazolium salt (WST-1) assay, live and dead cell assays, and flow cytometry. Dox-G-MoSe2 significantly inhibited MDA-MB-231 cancer cell proliferation under the illumination of an NIR laser at 808 nm. These results indicate that Dox-G-MoSe2 is a potentially valuable biomaterial for breast cancer therapy.

Amelioration of the progression of an atopic dermatitis-like skin lesion by silk peptide and identification of functional peptides.

The efficacy of silk peptide in treatment of atopic dermatitis was examined in a picryl chloride-induced atopic dermatitis model in NC/Nga mice. Silk peptide ameliorated the development of atopic dermatitis by lowering the serum IgE concentration. Treatment of cultured spleen cells with silk peptide reduced IgE production by enhancing the production of IFN-γ and reducing the level of IL-4. The functional peptides in the silk peptide were identified as mixture of GAGA sequences containing peptides by mass spectrometry and in vitro assay. Our findings indicate that silk peptide exerts an effect on atopic dermatitis by modulating the Th1/Th2 balance.

Treatment outcomes between concurrent chemoradiotherapy and combination of surgery, radiotherapy, and/or chemotherapy in stage III and IV maxillary sinus cancer: multi-institutional retrospective analysis.

PURPOSE: The incidence of maxillary sinus cancer (MSC) is extremely rare, representing less than 1% of all cancers. Because of its rarity, the management of locally advanced MSC is a challenging issue. The objective of the present study was to retrospectively compare the efficacy of 2 traditional treatment strategies, concurrent chemoradiotherapy (CCRT) versus combination of surgery and radiotherapy and/or chemotherapy (SRCT) in MSC. PATIENTS AND METHODS: From 1989 to 2010, 65 patients with histologically confirmed stage III or IVA/IVB were retrospectively analyzed. RESULTS: The median age of our subjects was 60 years (range 36 to 81). The present study involved 18 women (27.7%) and 47 men (72.3%). Of the 65 patients, 52 (80.0%) had squamous cell carcinoma. The TNM stage was stage III, as determined by the American Joint Committee on Cancer, 6th edition, in 27 patients (41.5%). Stage IVA or IVB was observed in 38 patients (58.5%). Of the 65 patients, 41 underwent treatment. Of these 41 patients, 26 and 15 patients underwent SRCT and CCRT, respectively. During the 75.6 months (range 6.4 to 249.4) of median follow-up, the median progression-free survival duration was 45.1 months (95% confidence interval 0.0 to 142.7). The 5-year overall survival rate was 64.8%. However, the patients who had undergone surgery had better progression-free survival (hazard ratio 2.363, 95% confidence interval 1.098 to 5.085, P = .028) and overall survival (hazard ratio 4.989, 95% confidence interval 1.646 to 15.118, P = .004). The SRCT group had a better progression-free survival (P = .043) and overall survival (P = .029) duration than did the CCRT group. CONCLUSION: SRCT might be superior to CCRT for locally advanced MSC. Additional studies comparing the treatment outcomes of CCRT with SRCT are warranted.

Longevity of organic layers of vertical flow ponds for sulfate reduction in treating mine drainages in South Korea.

This study was carried out to evaluate longevity of available organic materials used for sulfate-reducing bacteria (SRB) activity in vertical flow ponds (VFPs) to treat mine drainage in South Korea. Spent mushroom compost samples (SMC) were tested as substrates in VFPs and analyzed for total organic carbon in VFPs, and were collected to analyze total organic carbon (TOC), T-N, T-P, K, metals and residual cellulose to check the longevity assessment. Chemical analysis revealed that the average contents of Fe, Al and Mn in SMC of VFPs were 19,907, 32,137 and 434 mg/kg, respectively. The contents of Fe and Al in SMC of VFPs were much higher than those of the unused SMC (control), but to the contrary, those of Mn showed a reversed tendency. Average TOC content of the controls was 64.19% but in one of the VFP substrates was as low as 15.92%. This might be resulted from SRB consumed the available organic carbon in SMC as VFPs system aged. Contents of T-N in VFPs tended to decrease as VFPs aged. The residual cellulose ranged from 3.88 to 6.72% (g/g). There existed a negative relationship between residual cellulose contents and ages of VFPs. Assuming that SMC in all VFPs had similar compositions when the VFPs were initially established, trend analysis predicted that the amount of carbon source for SRB might be available for 12-15 years further, depending on VFPs.