Time to initiation of extracorporeal membrane oxygenation in conventional cardiopulmonary resuscitation affects the patient survival prognosis.

BACKGROUND: Cardiopulmonary resuscitation (CPR) is the cornerstone intervention for cardiac arrest, with extracorporeal CPR (ECPR) demonstrating enhanced survival and neurologic outcomes in in-hospital cardiac arrest. This study explores the time interval between CPR initiation and the onset of extracorporeal membrane oxygenation (ECMO) in ECPR recipients, investigating its impact on survival outcomes. METHODS: This retrospective analysis included 1950 adults who received CPR at a single medical center between March 2019 and April 2023. Data from 198 adult patients who had ECMO inserted during CPR were analyzed. The interval from CPR initiation to ECMO initiation was quantified and categorized as ≤20, 20-40, and >40 min. Cox regression analysis assessed associations between CPR-to-ECMO time and short- and long-term mortalities. RESULTS: Among the 198 patients who underwent ECPR, 116 (58.6%) experienced 30-day mortality. Initiation of ECMO within 20 min occurred in 46 (23.2%), whereas 74 (37.4%) had ECMO initiated after 40 min. Cox regression revealed a significant association between time from CPR to ECMO initiation and 30-day mortality (adjusted hazard ratio [HR]: 2.20 in >40 min, HR: 2.63 in 20-40 min, p = 0.006) and 6-month mortality (HR: 1.81, in >40 min, HR: 1.99 in 20-40 min, p = 0.021). CONCLUSIONS: This study revealed that, in ECPR recipients, a shorter duration between CPR initiation and ECMO flow commencement is associated with improved short- and long-term patient prognoses. These findings emphasize the critical role of timely ECMO application in optimizing outcomes for patients undergoing ECPR.

Impact of Financial Disclosures and Health Warnings on Youth and Young Adult Perceptions of Pro-E-cigarette Instagram Posts.

INTRODUCTION: We examined the impact of financial disclosures and warning labels on pro-e-cigarette Instagram posts and their association with attitudes toward the ad and product among youth and young adults. METHODS: During March to May 2021, we conducted a factorial experiment using an online convenience sample of youth and young adults (N = 1687, Mage = 21.54). Participants were randomized to one of four conditions: pro-e-cigarette Instagram posts with only a financial disclosure, only a warning label, both a financial disclosure + warning label, or no financial disclosure or warning label. After viewing the posts, participants answered questions regarding their attitude toward the ad and the product. We used one-way ANOVA to estimate the association of condition on outcomes controlling for demographics. RESULTS: Young adults who viewed Instagram posts with only a financial disclosure reported more positive attitudes toward the ad than those who viewed posts with both a financial disclosure + warning label (p < .05). Young adults who viewed posts with only a financial disclosure reported more positive attitudes toward the product than those who viewed posts with only a warning label, both a financial disclosure + warning label, and without either (ps < .05). Differences were not statistically significant for youth. E-cigarette use status was associated with increased positive attitudes toward the ad (p < .001) and product (p < .001) for all participants. CONCLUSIONS: Our results can inform policy interventions to mitigate the effects of e-cigarette social media marketing among youth and young adults. Including financial disclosures may not decrease appeal of e-cigarettes compared to posts without either. IMPLICATIONS: Findings from the study suggest that a warning label may be more effective in reducing the effects of pro-e-cigarette social media posts than a financial disclosure among young adults. Public health officials should examine additional strategies beyond financial disclosures and warning labels (eg, social media peer mentoring program) to offset the persuasive effects of pro-e-cigarette social media marketing posts on young people. Additional policy interventional efforts are needed to limit the impact of e-cigarette social media marketing.

Effects of Qigong Therapy on the Psychological Well-Being, Physical Health State, Sleep State, and Life Satisfaction of Older Adults Living in Community.

Older adults living in a community are looking for alternative and complementary methods to improve their healthy longevity and quality of life. This study aimed to examine the effects of the Qigong therapy on psychological well-being, physical health state, sleep state, and life satisfaction of older adults living in community. This study used a quasi-experimental pretest-posttest control group design. The study samples were 69 older adults (intervention, n = 34; control, n = 35) over 65 years old in community in South Korea. Qigong therapy was performed 50 minutes per session, twice a week for a total of 20 times over a 10-week period in a comfortable and quiet environment without external noise. Measures were the study participant's general characteristics survey, psychological well-being scale, Cornell Medical Index-Korean version, sleep scale, and life satisfaction scale standardized for the elderly. Effects of Qigong therapy according to interaction effect over time and the group showed statistically significant differences in psychological well-being, physical health state, sleep state, and life satisfaction. This study suggests that Qigong therapy was an effective nursing intervention for improving the psychological well-being, physical health state, sleep state, and life satisfaction of older adults living in community.

Comparison of the Effects of Multiple Frailty and Nutritional Indexes on Postoperative Outcomes in Critically Ill Patients Undergoing Lung Transplantation.

Background and Objective: Lung transplantation is the only life-extending therapy for end-stage pulmonary disease patients, but its risks necessitate an understanding of outcome predictors, with the frailty index and nutritional status being key assessment tools. This study aims to evaluate the relationship between preoperative frailty and nutritional indexes and the postoperative mortality rate in patients receiving lung transplants, and to determine which measure is a more potent predictor of outcomes. Materials and Methods: This study reviewed 185 adults who received lung transplants at a single medical center between January 2013 and May 2023. We primarily focused on postoperative 7-year overall survival. Other outcomes measured were short-term mortalities, acute rejection, kidney complications, infections, and re-transplantation. We compared the predictive abilities of preoperative nutritional and frailty indicators for survival using receiver operating characteristic curve analysis and identified factors affecting survival through regression analyses. Results: There were no significant differences in preoperative nutritional indicators between survivors and non-survivors. However, preoperative frailty indicators did differ significantly between these groups. Multivariate analysis revealed that the American Society of Anesthesiologists Class V, clinical frailty scale, and Charlson Comorbidity Index (CCI) were key predictors of 7-year overall survival. Of these, the CCI had the strongest predictive ability with an area under the curve of 0.755, followed by the modified frailty index at 0.731. Conclusions: Our study indicates that for critically ill patients undergoing lung transplantation, frailty indexes derived from preoperative patient history and functional autonomy are more effective in forecasting postoperative outcomes, including survival, than indexes related to preoperative nutritional status.

A Facile Strategy for the Fabrication of Cell-laden Porous Alginate Hydrogels Based on Two-phase Aqueous Emulsions.

Porous alginate hydrogels possess many advantages as cell carriers. However, current pore generation methods require either complex or harsh fabrication processes, toxic components, or extra purification steps, limiting the feasibility and affecting the cellular survival and function. In this study, a simple and cell-friendly approach to generate highly porous cell-laden alginate hydrogels based on two-phase aqueous emulsions is reported. The pre-gel solutions, which contain two immiscible aqueous phases of alginate and caseinate, are crosslinked by calcium ions. The porous structure of the hydrogel construct is formed by subsequently removing the caseinate phase from the ion-crosslinked alginate hydrogel. Those porous alginate hydrogels possess heterogeneous pores around 100 µm and interconnected paths. Human white adipose progenitors (WAPs) encapsulated in these hydrogels self-organize into spheroids and show enhanced viability, proliferation, and adipogenic differentiation, compared to non-porous constructs. As a proof of concept, this porous alginate hydrogel platform is employed to prepare core-shell spheres for coculture of WAPs and colon cancer cells, with WAP clusters distributed around cancer cell aggregates, to investigate cellular crosstalk. This efficacious approach is believed to provide a robust and versatile platform for engineering porous-structured alginate hydrogels for applications as cell carriers and in disease modeling.

A simple protein histidine kinase activity assay for high-throughput inhibitor screening.

Bacterial two-component systems (TCSs), which typically consist of a sensor histidine kinase (HK) and a response regulator (RR), have been investigated as attractive antibacterial drug targets. Unfortunately, current HK activity assays based on the quantification of autophosphorylated HKs are hampered by the instability of the phosphohistidine (pHis) product, rendering them ill-suited for high-throughput screenings. To address this challenge, we developed a simple HK activity assay using readily available reagents, which we have termed AUDECY (AUtophosphorylation-DEphosphorylation CYcle assay). Instead of trying to preserve the fragile pHis, we deliberately decomposed it with a pHis-specific phosphatase to constitute an ATPase-like cycle for convenient colorimetric measurements. This kinetic assay was successfully employed for the kinetic characterization of E. coli EnvZ and for high-throughput inhibitor screening of vancomycin-resistant Enterococcus faecium (VRE) VanS, of which histidine kinase activity was hardly detectable with conventional methods. Through the screening, we identified OSU-03012, a potent VanS HK inhibitor, which sensitized VRE toward vancomycin, highlighting the potential of AUDECY in HK inhibitor discovery.

Association of Vaping Identity and e-Cigarette Perceptions among Young Adults Who Vape.

Background: In the U.S., 9.3% of young adults currently vape. However, little is known about how vaping identity (i.e., internalizing vaping as an important part of oneself) can influence young adults' e-cigarette perceptions. The purpose of this study was to examine the association between vaping identity and e-cigarette perceptions among young adults. Methods: Young adults who vape (N = 252, Mage = 24.7) were recruited to participate in an online survey assessing a trusted source of health information, e-cigarette harm perceptions, and intentions to abstain from vaping. We estimated associations between vaping identity on outcomes and the interaction of vaping identity and combustible cigarette use on outcomes. Results: Participants with higher vaping identity reported lower trust in government health agencies and a doctor, and higher trust in the tobacco industry and e-cigarette industry (ps < 0.05). Those with higher vaping identity also reported lower e-cigarette harm perceptions and intentions to abstain from vaping (ps < 0.05). Conclusions: Findings show that higher vaping identity is associated with greater trust in the tobacco industry, lower trust in health experts, lower e-cigarette harm perceptions, and lower intentions to abstain from using e-cigarettes. This suggests that efforts to reduce vaping among young adults may need to leverage messages that reduce the credibility of the tobacco industry and prevent nonsmoking young adults from developing a vaping identity.

How Age and E-cigarette Use Status Interact to Influence E-cigarette Ad Perceptions.

Background: The prevalence of e-cigarette use among young people remains high. Young people are susceptible to e-cigarette advertising, although potential heterogeneity in perceptions of e-cigarette ads with respect to age and e-cigarette use history remains unexplored. We aimed to assess differences in perceptions of e-cigarette ads and product use intention, by age and e-cigarette use status. Methods: Participants from an online convenience sample (N = 497, Mage=31.9) viewed two randomly selected e-cigarette ads and reported their perceptions of the ads and product use intention. We used mixed effects linear regression models to estimate associations between age group (18-20 years, 21-25 years, 26+ years), e-cigarette use status (never, former, and current use), and their interaction effects, on outcomes related to perceptions of ads and use intention. Models controlled for demographics and other tobacco use. Results: Current e-cigarette users (vs. never users) and participants who were 26+ years old (vs. 18-20 years old) had greater liking of the ads, perceived ad relevance, and perceived ad effectiveness. Among current e-cigarette users, participants who were 26+ years old (vs. 18-20 years old) had lower use intention. Conclusion: The effect of e-cigarette ad exposures on perceptions of the ad and use intention is heterogeneous with respect to age group and e-cigarette use history. While ads appealed more to adults who were 26+ years old across e-cigarette use groups, current e-cigarette users who were 18-20 years old demonstrated high use intention following ad exposure, suggesting a need for marketing interventions to mitigate continued e-cigarette use among young people.

E-Cigarette Use among Sexual Minoritized Women and Nonbinary People Assigned Female at Birth: Assessing the Roles of Discrimination, Perceived Stress, and Social Support.

Background: Young adult sexual minoritized women (SMW) are at disproportionate risk for e-cigarette use, which may in part be due to excess minority stress imposed by discrimination exposure. While discrimination exposure is associated with risk for combustible tobacco/nicotine use among SMW, similar associations have yet to be tested with e-cigarettes. Moreover, it is unknown if discrimination-related risk may be mitigated by protective factors such as social support. This study examined concurrent associations of discrimination, perceived stress, and social support with past 30-day e-cigarette use in a sample of young adult SMW during the COVID-19 pandemic. Methods: N = 501 SMW and nonbinary people assigned female at birth (AFAB) aged 18-30 completed an online survey. A series of logistic regressions examined associations of discrimination, perceived stress, and four forms of social support received during the COVID-19 pandemic with past-30-day e-cigarette use. Results: Among SMW, greater perceived stress (OR = 1.10, p = .03), but not discrimination exposure, was associated with e-cigarette use. Associations of discrimination with e-cigarette use were nonsignificant when most forms of social support (emotional, material/financial, and virtual) were accounted for. Associations of perceived stress with e-cigarette use were strongest among those who needed but did not receive material support. Conclusions: Perceived stress, but not discrimination exposure, was associated with risk for e-cigarette use among young SMW during the COVID-19 pandemic. Effects of nonspecific stress may be compounded by insufficient material/financial support.

Implementation of Highly Stable Memristive Characteristics in an Organic-Inorganic Hybrid Resistive Switching Layer of Chitosan-Titanium Oxide with Microwave-Assisted Oxidation.

This study proposes a high-performance organic-inorganic hybrid memristor for the development of neuromorphic devices in the memristor-based artificial synapse. The memristor consists of a solid polymer electrolyte (SPE) chitosan layer and a titanium oxide (TiOx) layer grown with a low-thermal-budget, microwave-assisted oxidation. The fabricated Ti/SPE-chitosan/TiOx/Pt-structured memristor exhibited steady bipolar resistive switching (BRS) characteristics and demonstrated excellent endurance in 100-cycle repetition tests. Compared to SPE-chitosan memristors without a TiOx layer, the proposed organic-inorganic hybrid memristor demonstrated a higher dynamic range and a higher response to pre-synaptic stimuli such as short-term plasticity via paired-pulse facilitation. The effect of adding the TiOx layer on the BRS properties was examined, and the results showed that the TiOx layer improved the chemical and electrical superiority of the proposed memristor synaptic device. The proposed SPE-chitosan organic-inorganic hybrid memristor also exhibited a stable spike-timing-dependent plasticity, which closely mimics long-term plasticity. The potentiation and depression behaviors that modulate synaptic weights operated stably via repeated spike cycle tests. Therefore, the proposed SPE-chitosan organic-inorganic hybrid memristor is a promising candidate for the development of neuromorphic devices in memristor-based artificial synapses owing to its excellent stability, high dynamic range, and superior response to pre-synaptic stimuli.

Amyloid Against Amyloid: Dimeric Amyloid Fragment Ameliorates Cognitive Impairments by Direct Clearance of Oligomers and Plaques.

Amyloid-ß (Aß) in the form of neurotoxic aggregates is regarded as the main pathological initiator and key therapeutic target of Alzheimer's disease. However, anti-Aß drug development has been impeded by the lack of a target needed for structure-based drug design and low permeability of the blood-brain barrier (BBB). An attractive therapeutic strategy is the development of amyloid-based anti-Aß peptidomimetics that exploit the self-assembling nature of Aß and penetrate the BBB. Herein, we designed a dimeric peptide drug candidate based on the N-terminal fragment of Aß, DAB, found to cross the BBB and solubilize Aß oligomers and fibrils. Administration of DAB reduced amyloid burden in 5XFAD mice, and downregulated neuroinflammation and prevented memory impairment in the Y-maze test. Peptide mapping assays and molecular docking studies were utilized to elucidate DAB-Aß interaction. To further understand the active regions of DAB, we assessed the dissociative activity of DAB with sequence modifications.

Positive Eusocial Impacts on Ants by Taurine Derivatives.

The present study is to investigate potential eusocial effects on ants from treatment of taurine or its derivatives: galactose-taurine (GT) or xylose-taurine (XT). Japanese carpenter ants (Camponotus japonicus) were maintained on taurine-supplemented diets, and their performance was evaluated according to arbitrary eusocial indexes. Four classes of criteria were employed: establishment of residence chambers, survival at severe conditions, cooperative defense index (CDI), and population size. Taurine or its derivatives were administered orally in 0.1 mM sucrose solution. When fed with taurine or taurine derivatives, ants built more chambers than the non-fed control. Among the taurine groups, the XT-fed group showed the highest number of chambers. Differences in survivorship were obvious between the control and taurine-fed groups at the extreme conditions of light exposure and high temperature. More ants survived when fed with taurine or its derivatives. The taurine-supplemented groups took less time to organize a defense form than the control. The XT-fed group showed a high level of CDI which refer to the willingness to participate in defense against a foreign queen. The taurine-fed group sustained higher total numbers of ants. The XT-fed groups showed a 15% increase in the number of workers and an 11% increase in the number of eggs. The taurine-fed ants positively responded according to the eusocial vitality indexes, especially when fed with XT. In summary, these results show that ants respond more like superorganisms when treated with XT among taurine or its two derivatives.

Synergism Between Taurine and Dexamethasone in Anti-inflammatory Response in LPS-Activated Macrophages.

The aim of the present study is to examine the potential effect of dexamethasone (DEX) and taurine (TAU) on endoplasmic reticular stress (ERS) and inflammation. The macrophages were pre-treated with DEX or TAU, and the level of ERS and pro-inflammatory response was evaluated in LPS-activated macrophages. The expression of ERS marker proteins (GRP78 and CHOP) and the pro-inflammatory cytokines (IL-1ß and IL-6) was analyzed by immunoblotting and ELISA of LPS-induced macrophages. At lower concentrations (<50 nM), DEX alone reduced the levels of ERS and pro-inflammatory markers. Similarly, TAU reduced the expression of LPS-induced ERS and pro-inflammatory markers. When treated with a combination of DEX and TAU, however, the macrophages showed even a greater level of reduction in ERS and pro-inflammatory responses. The RT-qPCR data indicate that the reduction of ERS markers is caused by the inhibition of their own transcriptional expression. The significant level of reduction can be interpreted as a strong synergistic effect (p < 0.01). In summary, the results strongly indicate that a single pre-treatment of DEX or TAU may attenuate ERS and inflammation in LPS-induced macrophages at the concentrations tested in this study. Most importantly, concurrent treatment of macrophages by both agents reduced the level of ERS and pro-inflammatory cytokines in a synergistic fashion.

Minoritized Sexual Identity and Perceived Effectiveness of Instagram Public Health Messaging about E-cigarettes.

E-cigarette (EC) use in young adult sexual-minoritized women (SMW) is disproportionately higher than among heterosexual women and sexual-minoritized men. Public health messaging utilizing social branding, a method used to tailor health messages to one's identity, may help combat this problem. We conducted an online study with SMW (N= 457) and asked them to complete scales assessing their sexual minoritized identity affirmation and centrality. Participants were randomized to view socially branded messages discouraging EC use across three themes (general wellness, pride, health harms). Results revealed that overall lesbian, bisexual, or queer (LBQ) identity (affirmation and centrality) was significantly positively associated with perceived message effectiveness (PME) (p < .001). Identity affirmation was significantly associated with PME when controlling for identity centrality (p = .004). Interaction between identity affirmation and theme was significant (p= .02), as positive effects of identity affirmation on PME were greater when participants viewed pride-themed messages versus wellness (p= .03) or harms messages (p = .01). The findings suggest that socially branded EC prevention messages emphasizing sexual minoritized identity may be more effective for SMW with a strong connection to their LBQ identity. Future research should examine how identity and socially branded messages can impact health behaviors.

Characterization of Edwardsiella piscicida CK108 flagellin genes and evaluation of their potential as vaccine targets in the zebrafish model.

The control of bacterial pathogens, including Edwardsiella piscicida, in the aquaculture industry has high economic importance. This study aimed to identify a potential live vaccine candidate against E. piscicida infection to minimize the side effects and elicit immunity in the host. This study evaluated the virulence factors of E. piscicida CK108, with a special focus on the flagella. E. piscicida has two important homologous flagellin genes, namely flagellin-associated protein (fap) and flagellin domain-containing protein (fdp). CK226 (Δfap), CK247 (Δfdp) and CK248 (Δfap, fdp) mutant strains were constructed. Both CK226 and CK247 displayed decreased length and thickness of flagellar filaments, resulting in reduced bacterial swimming motility, while CK248 was non-motile as it lacked flagella. The loss of flagella and decreased motility was expected to decrease the pathogenicity of CK248. However, the median lethal dose (LD50 ) of CK248 against zebrafish was lower than those of the wild-type, CK226 and CK247 strains. The protective immunity and cytokine gene expression levels in the CK248-infected zebrafish were lower than those in the wild type-infected zebrafish. In conclusion, Fap and Fdp are essential for flagella formation and motility, and for stimulating fish immune response, which can be utilized as a potential adjuvants for E. piscicida vaccination.

High Light Acclimation Mechanisms Deficient in a PsbS-Knockout Arabidopsis Mutant.

The photosystem II PsbS protein of thylakoid membranes is responsible for regulating the energy-dependent, non-photochemical quenching of excess chlorophyll excited states as a short-term mechanism for protection against high light (HL) stress. However, the role of PsbS protein in long-term HL acclimation processes remains poorly understood. Here we investigate the role of PsbS protein during long-term HL acclimation processes in wild-type (WT) and npq4-1 mutants of Arabidopsis which lack the PsbS protein. During long-term HL illumination, photosystem II photochemical efficiency initially dropped, followed by a recovery of electron transport and photochemical quenching (qL) in WT, but not in npq4-1 mutants. In addition, we observed a reduction in light-harvesting antenna size during HL treatment that ceased after HL treatment in WT, but not in npq4-1 mutants. When plants were adapted to HL, more reactive oxygen species (ROS) were accumulated in npq4-1 mutants compared to WT. Gene expression studies indicated that npq4-1 mutants failed to express genes involved in plastoquinone biosynthesis. These results suggest that the PsbS protein regulates recovery processes such as electron transport and qL during long-term HL acclimation by maintaining plastoquinone biosynthetic gene expression and enhancing ROS homeostasis.

Hemp-Derived Nanovesicles Protect Leaky Gut and Liver Injury in Dextran Sodium Sulfate-Induced Colitis.

Hemp (Cannabis sativa L.) is used for medicinal purposes owing to its anti-inflammatory and antioxidant activities. We evaluated the protective effect of nanovesicles isolated from hemp plant parts (root, seed, hemp sprout, and leaf) in dextran sulfate sodium (DSS)-induced colitis in mice. The particle sizes of root-derived nanovesicles (RNVs), seed-derived nanovesicles (SNVs), hemp sprout-derived nanovesicles (HSNVs), and leaf-derived nanovesicles (LNVs) were within the range of 100-200 nm as measured by nanoparticle tracking analysis. Acute colitis was induced in C57BL/N mice by 5% DSS in water provided for 7 days. RNVs were administered orally once a day, leading to the recovery of both the small intestine and colon lengths. RNVs, SNVs, and HSNVs restored the tight (ZO-1, claudin-4, occludin) and adherent junctions (E-cadherin and α-tubulin) in DSS-induced small intestine and colon injury. Additionally, RNVs markedly reduced NF-κB activation and oxidative stress proteins in DSS-induced small intestine and colon injury. Tight junction protein expression and epithelial cell permeability were elevated in RNV-, SNV-, and HSNV-treated T84 colon cells exposed to 2% DSS. Interestedly, RNVs, SNVs, HSNVs, and LNVs reduced ALT activity and liver regeneration marker proteins in DSS-induced liver injury. These results showed for the first time that hemp-derived nanovesicles (HNVs) exhibited a protective effect on DSS-induced gut leaky and liver injury through the gut-liver axis by inhibiting oxidative stress marker proteins.

Therapeutic effect of steroids on vestibular neuritis: Systematic review and meta-analysis.

OBJECTIVES: The present meta-analysis sought to assess further evidence for the efficacy of steroids in vestibular neuritis (VN). METHODS: The PubMed, EMBASE and Cochrane Library databases were searched through 30 August 2019. The main outcome measure was dizziness handicap inventory (DHI) and secondary outcomes included complete caloric recovery and improvement of canal paresis (CP). The follow-up times were divided into short, mid and long-term. RESULTS: Among 276 records identified, 5 studies (n = 253) were included in the analysis. The therapeutic effect of steroid on VN was confirmed (Hedges' g = 0.172, 95% CI 0.05-0.30, p = .006). Although there was no significant difference between steroids and control in the DHI score (Hedges' g = -0.323, 95% CI -0.533 to -0.113, p < .01), significant effect was seen on complete caloric recovery and improvement in CP (Hedges' g = 0.364, 95% CI 0.18-0.55, p < .0001; Hedges' g = 0.592, 95% CI 0.32-0.59, p < .0001). CONCLUSIONS: The results suggest that corticosteroids have an effect on the results of caloric tests for VN recovery, especially in long-term follow-up. However, in terms of dizziness handicap, we did not find any evidence of positive effect on corticosteroid. More data are required before recommendations can be made regarding management in patients on corticosteroids.

3D printed alginate bead generator for high-throughput cell culture.

Alginate hydrogel beads are a common platform for generating 3D cell cultures in biomedical research. Simple methods for bead generation using a manual pipettor or syringe are low-throughput and produce beads showing high variability in size and shape. To address these challenges, we designed a 3D printed bead generator that uses an airflow to cleave beads from a stream of hydrogel solution. The performance of the proposed alginate bead generator was evaluated by changing the volume flow rates of alginate (QAlg) and air (QA), the diameter of device nozzle (d) and the concentration of alginate gel solution (C). We identified that the diameter of beads (D = 0.9 -2.8 mm) can be precisely controlled by changing QA and d. Also the bead generation frequency (f) can be tuned by changing QAlg. Finally, we demonstrated that viability and biological function (pericellular matrix deposition) of chondrocytes were not adversely affected by high f using this bead generator. Because 3D printing is becoming a more accessible technique, our unique design will allow greater access to average biomedical research laboratories, STEM education and industries in cost- and time-effective manner.

Five Surfactin Isomers Produced during Cheonggukjang Fermentation by Bacillus pumilus HY1 and Their Properties.

The cyclic lipopeptide produced from Bacillus pumilus strain HY1 was isolated from Korean soybean sauce cheonggukjang. The chemical structures of the surfactin isomers were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). The five potential surfactin isoforms were detected with protonated masses of m/z 994.7, 1008.7, 1022.7, 1036.7, and 1050.7 and different structures in combination with Na+, K+, and Ca2+ ions. ESI-MS/MS analysis revealed that the isolated surfactin possessed the precise amino acid sequence LLVDLL and hydroxyl fatty acids with 12 to 16 carbons. The surfactin content during cheonggukjang fermentation increased from 0.3 to 51.2 mg/kg over 60 h of fermentation. The mixture of five surfactin isoforms of cheonggukjang inhibited the growth of two cancer cell lines. The growth of both MCF-7 and Caco-2 cells was strongly inhibited with 100 µg/µL of surfactin. This study is the first-time report of five surfactin isomers of Bacillus pumilus strain HY1 during Korean soybean sauce cheonggukjang fermentation, which has cytotoxic properties.