Stroke caregivers' perception on instant messaging application use for psychological intervention: a qualitative study.

In caring for patients with stroke, the leading cause of death and disability affecting over 80 million people worldwide, caregivers experience substantial psychological and physical burdens and difficulties in help-seeking owing to physical and time-constraints. Social distancing measures imposed during the coronavirus disease 2019 (COVID-19) pandemic further restricted them from using caregiver support services. While the use of telehealth emerged as a global prevailing trend during the COVID-19 pandemic, evidence for utilising instant messaging (IM) applications for psychological intervention is scanty. This study aimed to explore stroke caregivers' perceived potential utility of IM-delivered psychological intervention. Between January and August 2020, 36 adult family stroke caregivers in Hong Kong were recruited to individual telephone semi-structured interviews using purposive sampling. The interviews were audio-recorded, transcribed verbatim and analysed using an interpretive description approach. Three themes of caregivers' perceptions towards IM-delivered psychological intervention emerged: perceived high convenience and ease of use, perceived advantages that overcome existing barriers to services and message delivery tailored to individual needs. Our findings suggested that there is an imminent need among stroke caregivers for personalised psychological interventions and that IM is a potential modality for overcoming existing barriers in delivering accessible support to caregivers in real-time, real-world settings. Our study highlighted caregivers' acceptance and perceived benefits of IM-delivered psychological intervention and provided practical insights into the design of IM-delivered psychological interventions.

Cervical spine reconstruction after total vertebrectomy using customized three-dimensional-printed implants in dogs.

BACKGROUND: Sufficient surgical resection is necessary for effective tumor control, but is usually limited for vertebral tumors, especially in the cervical spine in small animal neurosurgery. OBJECTIVE: To evaluate the primary stability and safety of customized three-dimensional (3D)-printed implants for cervical spine reconstruction after total vertebrectomy. METHODS: Customized guides and implants were designed based on computed tomography (CT) imaging of five beagle cadavers and were 3D-printed. They were used to reconstruct C5 after total vertebrectomy. Postoperative CT images were obtained to evaluate the safety and accuracy of screw positioning. After harvesting 10 vertebral specimens (C3-C7) from intact (group A) and implanted spines (group B), implant stability was analyzed using a 4-point bending test comparing with groups A and C (reconstituted with plate and pins/polymethylmethacrylate after testing in Group A). RESULTS: All customized implants were applied without gross neurovascular damage. In addition, 90% of the screws were in a safe area, with 7.5% in grade 1 (< 1.3 mm) and 2.5% in grade 2 (> 1.3 mm). The mean entry point and angular deviations were 0.81 ± 0.43 mm and 6.50 ± 5.11°, respectively. Groups B and C significantly decreased the range of motion (ROM) in C3-C7 compared with intact spines (p = 0.033, and 0.018). Both groups reduced overall ROM and neutral zone in C4-C6, but only group B showed significance (p = 0.005, and 0.027). CONCLUSION: Customized 3D-printed implants could safely and accurately replace a cervical vertebra in dog cadavers while providing primary stability.

Neddylation of insulin receptor substrate acts as a bona fide regulator of insulin signaling and its implications for cancer cell migration.

Irregularities in insulin signaling have significantly increased the risk of various cancers, yet the precise underlying mechanisms remain unclear. Within our study, we observed that inhibiting neddylation enhances cancer cell migration across different cancer types by activating both insulin receptor substrates 1 and 2 (IRS1 and IRS2), along with the PI3K/AKT signaling pathway. Notably, in the context of high-grade serous carcinoma (HGSC) patients, whether they had type 2 diabetes mellitus or not, IRS1 and IRS2 displayed a parallel relationship with each other while exhibiting an inverse relationship with NEDD8. We also identified C-CBL as an E3 ligase responsible for neddylating IRS1 and IRS2, with clinical evidence further confirming a reciprocal relationship between C-CBL and pAKT, thereby reinforcing the tumor suppressive role of C-CBL. Altogether, these findings suggest that neddylation genuinely participates in IRS1 and IRS2-dependent insulin signaling, effectively suppressing cancer cell migration. Thus, caution is advised when considering neddylation inhibitors as a treatment option for cancer patients, particularly those presenting with insulin signaling dysregulations linked to conditions like obesity-related type 2 diabetes or hyperinsulinemia.

Palmitoylation-driven PHF2 ubiquitination remodels lipid metabolism through the SREBP1c axis in hepatocellular carcinoma.

Palmitic acid (PA) is the most common fatty acid in humans and mediates palmitoylation through its conversion into palmitoyl coenzyme A. Although palmitoylation affects many proteins, its pathophysiological functions are only partially understood. Here we demonstrate that PA acts as a molecular checkpoint of lipid reprogramming in HepG2 and Hep3B cells. The zinc finger DHHC-type palmitoyltransferase 23 (ZDHHC23) mediates the palmitoylation of plant homeodomain finger protein 2 (PHF2), subsequently enhancing ubiquitin-dependent degradation of PHF2. This study also reveals that PHF2 functions as a tumor suppressor by acting as an E3 ubiquitin ligase of sterol regulatory element-binding protein 1c (SREBP1c), a master transcription factor of lipogenesis. PHF2 directly destabilizes SREBP1c and reduces SREBP1c-dependent lipogenesis. Notably, SREBP1c increases free fatty acids in hepatocellular carcinoma (HCC) cells, and the consequent PA induction triggers the PHF2/SREBP1c axis. Since PA seems central to activating this axis, we suggest that levels of dietary PA should be carefully monitored in patients with HCC.

[Analysis of ROX Index, ROX-HR Index, and SpO2/FIO2 Ratio in Patients Who Received High-Flow Nasal Cannula Oxygen Therapy in Pediatric Intensive Care Unit].

PURPOSE: This study aimed to evaluate the use of the respiratory rate oxygenation (ROX) index, ROX-heart rate (ROX-HR) index, and saturation of percutaneous oxygen/fraction of inspired oxygen ratio (SF ratio) to predict weaning from high-flow nasal cannula (HFNC) in patients with respiratory distress in a pediatric intensive care unit. METHODS: A total of 107 children admitted to the pediatric intensive care unit were enrolled in the study between January 1, 2017, and December 31, 2021. Data on clinical and personal information, ROX index, ROX-HR index, and SF ratio were collected from nursing records. The data were analyzed using an independent t-test, χ² test, Mann-Whitney U test, and area under the curve (AUC). RESULTS: Seventy-five (70.1%) patients were successfully weaned from HFNC, while 32 (29.9%) failed. Considering specificity and sensitivity, the optimal cut off points for predicting treatment success and failure of HFNC oxygen therapy were 6.88 and 10.16 (ROX index), 5.23 and 8.61 (ROX-HR index), and 198.75 and 353.15 (SF ratio), respectively. The measurement of time showed that the most significant AUC was 1 hour before HFNC interruption. CONCLUSION: The ROX index, ROX-HR index, and SF ratio appear to be promising tools for the early prediction of treatment success or failure in patients initiated on HFNC for acute hypoxemic respiratory failure. Nurses caring for critically ill pediatric patients should closely observe and periodically check their breathing patterns. It is important to continuously monitor three indexes to ensure that ventilation assistance therapy is started at the right time.

Cadaveric Biomechanical Study of Partial Glenoid Arthroplasty Versus the Latarjet Procedure for Anterior Glenoid Bone Loss.

BACKGROUND: For severe anterior glenoid bone loss due to recurrent shoulder instability, the Latarjet procedure offers a dynamic sling effect in addition to bone augmentation. Yet, it heavily alters the surrounding anatomy, while fixation and graft union issues are also common. PURPOSE/HYPOTHESIS: The purpose of this study was to compare a novel printed 3-dimensional (3D) partial glenoid arthroplasty (PGA) implant with the classic Latarjet procedure. It was hypothesized that by replicating the original glenoid geometry and preserving soft tissue anatomy, PGA may better reproduce normal joint kinematics. In addition, the locking screw construct may offer stronger fixation. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 14 matched cadaveric shoulders were tested. The PGA implant was 3D printed in titanium based on preoperative computed tomography. The intact, 25% anterior glenoid bone loss, and postoperative states were tested in the scapular and coronal planes. The following parameters were measured: articular surface area and stepoff, rotational range of motion and the humeral head apex position during rotation, and load and linear stiffness at 25% anterior translation and at 2-mm construct displacement. RESULTS: The baseline dimensions of the glenoid articular surface were comparable between the groups. The articular surface area after PGA was significantly larger (P = .006) with less articular stepoff (P = .030). PGA better approximated the intact state's external (P = .006) and total (P = .019) rotational range of motion in the scapular plane. The course of the humeral head apex after PGA better followed that of the intact state (P < .001). Resistance against anterior translation after PGA was not significantly different compared with after the Latarjet procedure. Greater linear stiffness (P = .031) and loading (P = .002) at 2-mm construct displacement were demonstrated in the PGA group. CONCLUSION: In addressing anterior glenoid bone loss, PGA better approximated intact glenohumeral joint kinematics compared with the Latarjet procedure with less articular stepoff in a cadaveric model. PGA was comparable in resisting anterior translation while being significantly stronger against loading at 2-mm construct displacement. Further clinical studies are warranted to validate this novel procedure. CLINICAL RELEVANCE: A 3D-printed PGA implant may offer an alternative treatment option for severe glenoid bone loss due to shoulder instability, overcoming the previous drawbacks of the Latarjet procedure, including altered kinematics, fixation failure, and hardware issues.

A Comparative Study of Titanium Cranioplasty for Extensive Calvarial Bone Defects: Three-Dimensionally Printed Titanium Implants Versus Premolded Titanium Mesh.

OBJECTIVE: This study compared the complications and symmetry outcomes between 3-dimensionally printed titanium implants and premolded titanium mesh in patients with extensive calvarial bone defects. METHODS: This retrospective analysis included patients with calvarial defects >50 cm2 undergoing cranioplasty who received either a 3-dimensionally printed titanium implant manufactured by selective laser melting techniques (N = 12) or a premolded titanium mesh customized onto a 3-dimensionally printed skull template (N = 23). Complications including intracranial infection, hardware extrusion, wound dehiscence, and cerebrospinal fluid leaks were investigated. Predictive factors affecting complications were investigated to identify the odds ratios in univariate and multivariate analyses. The symmetry was assessed by calculating the root mean square deviation, which showed the morphological deviation of the selected area compared with the mirrored image of the contralateral region. RESULTS: The overall complication rate was 26.1% (6/23 patients) in the premolded titanium group and 16.7% (2/12 patients) in the 3-dimensionally printed group. The reoperation rates did not differ significantly between the 2 groups (3-dimensionally printed group, 16.7%, versus premolded group, 21.7%). In multivariate analysis, only the number of previous cranial operation was significantly associated with the complication rate (odds ratio, 2.42; 95% confidence interval, 1.037-5.649; P = 0.041). The mean ± SD of the root mean square deviation was significantly smaller in the 3-dimensionally printed group (2.58 ± 0.93 versus 4.82 ± 1.31 mm, P < 0.001). CONCLUSIONS: The 3-dimensionally printed titanium implant manufactured by the selective laser melting technique showed comparable stability and improved symmetry outcomes compared with the conventional titanium mesh in the reconstruction of extensive calvarial defects.

Effectiveness of individualized 3D titanium-printed Orthognathic osteotomy guides and custom plates.

BACKGROUND: Computer-aided design/manufacturing (CAD/CAM) technology was developed to improve surgical accuracy and minimize errors in surgical planning and orthognathic surgery. However, its accurate implementation during surgery remains a challenge. Hence, we compared the accuracy and stability of conventional orthognathic surgery and the novel modalities, such as virtual simulation and three-dimensional (3D) titanium-printed customized surgical osteotomy guides and plates. METHODS: This prospective study included 12 patients who were willing to undergo orthognathic surgery. The study group consisted of patients who underwent orthognathic two-jaw surgery using 3D-printed patient-specific plates processed by selective laser melting and an osteotomy guide; orthognathic surgery was also performed by the surgeon directly bending the ready-made plate in the control group. Based on the preoperative computed tomography images and intraoral 3D scan data, a 3D virtual surgery plan was implemented in the virtual simulation module, and the surgical guide and bone fixation plate were fabricated. The accuracy and stability were evaluated by comparing the results of the preoperative virtual simulation (T0) to those at 7 days (T1) and 6 months (T2) post-surgery. RESULT: The accuracy (ΔT1‒T0) and stability (ΔT2‒T1) measurements, using 11 anatomical references, both demonstrated more accurate results in the study group. The mean difference of accuracy for the study group (0.485 ± 0.280 mm) was significantly lower than in the control group (1.213 ± 0.716 mm) (P < 0.01). The mean operation time (6.83 ± 0.72 h) in the control group was longer than in the study group (5.76 ± 0.43 h) (P < 0.05). CONCLUSION: This prospective clinical study demonstrated the accuracy, stability, and effectiveness of using virtual preoperative simulation and patient-customized osteotomy guides and plates for orthognathic surgery.

[Development and Psychometric Evaluation of the Ischemic Stroke Distress Scale (ISDS)].

PURPOSE: This study aimed to develop a scale to measure distress in patients with ischemic stroke and verify its validity and reliability. METHODS: Preliminary items were developed from literature review and in-depth interviews. The final preliminary scale was confirmed through a content validity test of eight experts and a preliminary survey of 10 stroke patients. The participants for psychometric testing were 305 stroke patients in the outpatient clinic. Validity and reliability analyses included item analysis, exploratory and confirmatory factor analysis, convergent validity, known-group validity, and internal consistency of the scale. RESULTS: The final scale consisted of 17 items and 3 factors. The three distinct factors were 'self-deprecation, worry about future health, and withdrawal from society' and this structure was validated using a confirmatory factor analysis. Convergent validity was supported by comparison with the Center for Epidemiologic Studies Depression Scale (r = .54, p < .001) and Brief Illness Perception Questionnaire (r = .67, p < .001). Known-groups validity was verified by dividing groups according to 'duration since diagnosis' (t = 2.65, p = .009), 'presence of sequela' (t = 10.16, p < .001), and 'awareness of distress' (t = 12.09, p < .001). The internal consistency of the scale using Cronbach's α for the total items was .93. CONCLUSION: The Ischemic Stroke Distress Scale is a valid and reliable tool that reflects stroke distress effectively. It is expected to be used as a basic tool to develop various intervention strategies to reduce distress in ischemic stroke patients.

Synthesis of Novel Shape Memory Thermoplastic Polyurethanes (SMTPUs) from Bio-Based Materials for Application in 3D/4D Printing Filaments.

Bio-based thermoplastic polyurethanes have attracted increasing attention as advanced shape memory materials. Using the prepolymer method, novel fast-responding shape memory thermoplastic polyurethanes (SMTPUs) were prepared from 100% bio-based polyester polyol, poly-propylene succinate derived from corn oil, diphenyl methane diisocyanate, and bio-based 1,3-propanediol as a chain extender. The morphologies of the SMTPUs were investigated by Fourier transform infrared spectroscopy, atomic force microscopy, and X-ray diffraction, which revealed the interdomain spacing between the hard and soft phases, the degree of phase separation, and the intermixing level between the hard and soft phases. The thermal and mechanical properties of the SMTPUs were also investigated, wherein a high hard segment content imparted unique properties that rendered the SMTPUs suitable for shape memory applications at varying temperatures. More specifically, the SMTPUs exhibited a high level of elastic elongation and good mechanical strength. Following compositional optimization, a tensile strength of 24-27 MPa was achieved, in addition to an elongation at break of 358-552% and a hardness of 84-92 Shore A. Moreover, the bio-based SMTPU exhibited a shape recovery of 100%, thereby indicating its potential for use as an advanced temperature-dependent shape memory material with an excellent shape recoverability.

Hypoxia inducible factor-1α promotes trichogenic gene expression in human dermal papilla cells.

Dermal papilla cells (DPCs) play critical roles in hair follicle development, but the underlying mechanisms that contribute to hair regeneration have yet to be fully elucidated, particularly in terms of alterations in androgenetic alopecia patients. In this study, we demonstrated that hypoxia-inducible factor-1α (HIF-1α) is suppressed in scalp tissues of androgenetic alopecia patients and potentially associated with hair follicle development. Using RT-qPCR and western blot, we found that mRNA and protein levels of trichogenic genes, LEF1 and versican (VCAN), were attenuated in HIF-1α knockdown DPCs. Under an in vivo mimicked environment in a three-dimensional spheroid culture, HIF-1α-suppressed DPCs downregulated the expression of hair induction-related genes. Finally, treatment with a HIF-1α activator resulted in the elevated expression of trichogenic genes in DPCs. This study highlights the importance of dermal HIF-1α expression in regulating trichogenic genes and provides a promising therapeutic target and a fundamental tissue engineering approach for hair loss treatment.

Bone beads enveloped with vascular endothelial cells for bone regenerative medicine.

The transplantation of pre-vascularized bone grafts is a promising strategy to improve the efficacy of engraftment and bone regeneration. We propose a hydrogel microbead-based approach for preparing vascularized and high-density tissue grafts. Mesenchymal stem cell-encapsulated collagen microgels (2 µL), termed bone beads, were prepared through spontaneous constriction, which improved the density of the mesenchymal stem cells and collagen molecules by more than 15-fold from the initial day of culture. Constriction was attributed to cell-attractive forces and involved better osteogenic differentiation of mesenchymal stem cells than that of spheroids. This approach was scalable, and ∼2000 bone beads were prepared semi-automatically using a liquid dispenser and spinner flask. The mechanical stimuli in the spinner flask further improved the osteogenic differentiation of the mesenchymal stem cells in the bone beads compared with that in static culture. Vascular endothelial cells readily attach to and cover the surface of bone beads. The in vitro assembly of the endothelial cell-enveloped bone beads resulted in microchannel formation in the interspaces between the bone beads. Significant effects of endothelialization on in vivo bone regeneration were shown in rats with cranial bone defects. The use of endothelialized bone beads may be a scalable and robust approach for treating large bone defects. STATEMENT OF SIGNIFICANCE: A unique aspect of this study is that the hMSC-encapsulated collagen microgels were prepared through spontaneous constriction, leading to the enrichment of collagen and cell density. This constriction resulted in favorable microenvironments for the osteogenic differentiation of hMSCs, which is superior to conventional spheroid culture. The microgel beads were then enveloped with vascular endothelial cells and assembled to fabricate a tissue graft with vasculature in the interspaces among the beads. The significant effects of endothelialization on in vivo bone regeneration were clearly demonstrated in rats with cranial bone defects. We believe that microgel beads covered with vascular endothelial cells provide a promising approach for engineering better tissue grafts for bone-regenerative medicine.

Oncologic Safety and Efficacy of Cell-Assisted Lipotransfer for Breast Reconstruction in a Murine Model of Residual Breast Cancer.

BACKGROUND: Cell-assisted lipotransfer (CAL) is a novel technique for fat grafting that combines the grafting of autologous fat and adipose-derived stromal cells (ASCs) to enhance fat graft retention; however, its oncologic safety is controversial. METHODS: Herein, we investigated the oncologic safety of CAL for breast reconstruction using a murine model of residual breast cancer. Various concentrations of 4T1 cells (murine breast cancer cells) were injected into female mastectomized BALB/c mice to determine the appropriate concentration for injection. One week after injection, mice were divided into control (100 µL fat), low CAL (2.5 × 105 ASCs/100 µL fat), and high CAL (1.0 × 106 ASCs/100 µL fat) groups, and fat grafting was performed. The injection of 5.0 × 103 4T1 cells was appropriate to produce a murine model of residual breast cancer. RESULTS: The weight of the fat tumor mass was significantly higher in the high CAL group than in the other groups (p < 0.05). However, the estimated tumor weight was not significantly different between the groups. Additionally, the fat graft survival rate was significantly higher in the high CAL group than in the control and low CAL groups (p < 0.05). No significant difference was noted in the percentage of Ki-67-positive cells, suggesting that tumor proliferation was not significantly different between the groups. CONCLUSION: In summary, CAL significantly improved fat graft survival without affecting tumor size and proliferation in a murine model of residual breast cancer. These results highlight the oncologic safety of CAL for breast reconstruction. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

One-Shot Synthesis of Thermoplastic Polyurethane Based on Bio-Polyol (Polytrimethylene Ether Glycol) and Characterization of Micro-Phase Separation.

In this study, a series of bio-based thermoplastic polyurethane (TPU) was synthesized via the solvent-free one-shot method using 100% bio-based polyether polyol, prepared from fermented corn, and 1,4-butanediol (BDO) as a chain extender. The average molecular weight, degree of phase separation, thermal and mechanical properties of the TPU-based aromatic (4,4-methylene diphenyl diisocyanate: MDI), and aliphatic (bis(4-isocyanatocyclohexyl) methane: H12MDI) isocyanates were investigated by gel permeation chromatography, Fourier transform infrared spectroscopy, atomic force microscopy, X-ray Diffraction, differential scanning calorimetry, dynamic mechanical thermal analysis, and thermogravimetric analysis. Four types of micro-phase separation forms of a hard segment (HS) and soft segment (SS) were suggested according to the [NCO]/[OH] molar ratio and isocyanate type. The results showed (a) phase-mixed disassociated structure between HS and SS, (b) hydrogen-bonded structure of phase-separated between HS and SS forming one-sided hard domains, (c) hydrogen-bonded structure of phase-mixed between HS, and SS and (d) hydrogen-bonded structure of phase-separated between HS and SS forming dispersed hard domains. These phase micro-structure models could be matched with each bio-based TPU sample. Accordingly, H-BDO-2.0, M-BDO-2.0, H-BDO-2.5, and M-BDO-3.0 could be related to the (a)-form, (b)-form, (c)-form, and (d)-form, respectively.

[Effects of the Advanced Practice Nurse-Led Psychoeducational Program for Colorectal Cancer Survivors].

PURPOSE: This study aimed to investigate the effects of an advanced practice nurse-led psychoeducational program on distress, anxiety, depression, coping with cancer (CWC), health promotion behavior (HPB), and quality of life (QOL) among colorectal cancer survivors. METHODS: This study was designed as a quasi-experimental study with a non-equivalent control group pretest-posttest. The participants were survivors of colorectal cancer who underwent follow-up care. There were 39 survivors: 19 in the experimental group and 20 in the control group. The experimental group performed a psychoeducational program for 120 minutes per session, once a week for a total of six weeks, while the control group received routine education and counseling. Distress, anxiety, depression, CWC, HPB, and QOL were investigated before, immediately after, and 4 weeks after the intervention. The data were analyzed with SPSS/WIN ver. 24.0, using repeated measures ANOVA. RESULTS: There were significant interactions between time and group for distress and anxiety. In addition, CWC interacted with the total of CWC and interpersonal coping, and QOL interacted with the total of QOL and functional status. However, there were no significant differences in the depression or HPB scores. CONCLUSION: Based on the results of this study, we expect that this program can be used as an effective intervention for colorectal cancer survivors.

Lipid metabolic reprogramming by hypoxia-inducible factor-1 in the hypoxic tumour microenvironment.

Cancer cells rewire metabolic processes to adapt to the nutrient- and oxygen-deprived tumour microenvironment, thereby promoting their proliferation and metastasis. Previous research has shown that modifying glucose metabolism, the Warburg effect, makes glycolytic cancer cells more invasive and aggressive. Lipid metabolism has also been receiving attention because lipids function as energy sources and signalling molecules. Because obesity is a risk factor for various cancer types, targeting lipid metabolism may be a promising cancer therapy. Here, we review the lipid metabolic reprogramming in cancer cells mediated by hypoxia-inducible factor-1 (HIF-1). HIF-1 is the master transcription factor for tumour growth and metastasis by transactivating genes related to proliferation, survival, angiogenesis, invasion, and metabolism. The glucose metabolic shift (the Warburg effect) is mediated by HIF-1. Recent research on HIF-1-related lipid metabolic reprogramming in cancer has confirmed that HIF-1 also modifies lipid accumulation, ß-oxidation, and lipolysis in cancer, triggering its progression. Therefore, targeting lipid metabolic alterations by HIF-1 has therapeutic potential for cancer. We summarize the role of the lipid metabolic shift mediated by HIF-1 in cancer and its putative applications for cancer therapy.

Lower troponin expression in the right ventricle of rats explains interventricular differences in E-C coupling.

Despite distinctive functional and anatomic differences, a precise understanding of the cardiac interventricular differences in excitation-contraction (E-C) coupling mechanisms is still lacking. Here, we directly compared rat right and left cardiomyocytes (RVCM and LVCM). Whole-cell patch clamp, the IonOptix system, and fura-2 fluorimetry were used to measure electrical properties (action potential and ionic currents), single-cell contractility, and cytosolic Ca2+ ([Ca2+]i), respectively. Myofilament proteins were analyzed by immunoblotting. RVCM showed significantly shorter action potential duration (APD) and higher density of transient outward K+ current (Ito). However, the triggered [Ca2+]i change (Ca2+ transient) was not different, while the decay rate of the Ca2+ transient was slower in RVCM. Although the relaxation speed was also slower, the sarcomere shortening amplitude (ΔSL) was smaller in RVCM. SERCA activity was ∼60% lower in RVCM, which is partly responsible for the slower decay of the Ca2+ transient. Immunoblot analysis revealed lower expression of the cardiac troponin complex (cTn) in RVCM, implying a smaller Ca2+ buffering capacity (κS), which was proved by in situ analysis. The introduction of these new levels of cTn, Ito, and SERCA into a mathematical model of rat LVCM reproduced the similar Ca2+ transient, slower Ca2+ decay, shorter APD, and smaller ΔSL of RVCM. Taken together, these data show reduced expression of cTn proteins in the RVCM, which provides an explanation for the interventricular difference in the E-C coupling kinetics.

Emotional Labor and Burnout of Public Health Nurses during the COVID-19 Pandemic: Mediating Effects of Perceived Health Status and Perceived Organizational Support.

The purpose of this study was to identify the mediating effects of perceived health status (PHS) and perceived organizational support (POS) in the association between emotional labor and burnout in public health nurses (PHNs). The participants were 207 PHNs convenience sampled from 30 public health centers and offices in Jeju, Korea. Data regarding emotional labor, PHS, POS, and burnout were collected between February and March 2021 using a structured questionnaire. Collected data were analyzed by Pearson's correlation coefficient and multiple regression analysis. Burnout of PHNs was positively correlated with emotional labor (r = 0.64, p < 0.001) and negatively correlated with PHS (r = -0.51, p < 0.001) and POS (r = -0.51, p < 0.001). In the association between emotional labor and burnout, PHS (B = -1.36, p < 0.001) and POS (B = -0.42, p = 0.001) had a partial mediating effect. Reduction of burnout among PHNs requires not only effective management of emotional labor but also personal and organizational efforts to improve PHS and POS.