Changes in smoking patterns and characteristics of Koreans using the Korea National Health and Nutrition Examination Survey 2013-2021 data.

OBJECTIVES: This study explored factors related to Korean adults' smoking patterns and also the reasons for using new types of tobacco products. STUDY DESIGN: Cross-sectional survey. METHODS: Data from the Korea National Health and Nutrition Examination Survey from 2013 to 2021 were used. The prevalence of the use of electronic cigarettes (e-cigarettes) or heated tobacco products (HTPs) alone or in combination with conventional cigarettes (CC) and the reasons for using new tobacco products are presented. Factors associated with using new types of tobacco products alone or in combination with CC compared to exclusive CC users were identified using multinomial logistic regression analysis. RESULTS: The prevalence of current smoking was 25.54% in 2013 and 23.05% in 2021, with no significant change. The prevalence of CC decreased from 23.39% in 2013 to 15.77% in 2021. The prevalence of new tobacco use in combination with CC did not show a definite trend. The prevalence of exclusive use of new tobacco was <1% until 2018 and has rapidly increased thereafter. Of the HTPs users, 46.68% responded with 'no cigarette smell' as the main reason for HTPs use, followed by 'It seems less harmful than cigarette' (19.19%), and 'It seems to be helpful for quitting smoking' (15.04%). Of the e-cigarette users, 45.19% responded 'It seems to be helpful for quitting smoking' as the main reason for e-cigarette use, followed by 'It is less harmful than cigarettes' (19.98%). Compared to CC users, new tobacco users were younger, had a higher household income or education, and used more nutritional supplements. CONCLUSION: Regulations for newer tobacco products are more lenient than for traditional cigarettes, leading to misunderstandings, especially among women and young people. To increase awareness of the risks of these products, specific policies such as disclosure of ingredients, ban on online sales, and increase in consumption tax, are needed.

Search for Boosted Dark Matter in COSINE-100.

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7 kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

In vitro formation and extended culture of highly metabolically active and contractile tissues.

3D cell culture models have gained popularity in recent years as an alternative to animal and 2D cell culture models for pharmaceutical testing and disease modeling. Polydimethylsiloxane (PDMS) is a cost-effective and accessible molding material for 3D cultures; however, routine PDMS molding may not be appropriate for extended culture of contractile and metabolically active tissues. Failures can include loss of culture adhesion to the PDMS mold and limited culture surfaces for nutrient and waste diffusion. In this study, we evaluated PDMS molding materials and surface treatments for highly contractile and metabolically active 3D cell cultures. PDMS functionalized with polydopamine allowed for extended culture duration (14.8 ± 3.97 days) when compared to polyethylamine/glutaraldehyde functionalization (6.94 ± 2.74 days); Additionally, porous PDMS extended culture duration (16.7 ± 3.51 days) compared to smooth PDMS (6.33 ± 2.05 days) after treatment with TGF-ß2 to increase culture contraction. Porous PDMS additionally allowed for large (13 mm tall × 8 mm diameter) constructs to be fed by diffusion through the mold, resulting in increased cell density (0.0210 ± 0.0049 mean nuclear fraction) compared to controls (0.0045 ± 0.0016 mean nuclear fraction). As a practical demonstration of the flexibility of porous PDMS, we engineered a vascular bioartificial muscle model (VBAM) and demonstrated extended culture of VBAMs anchored with porous PDMS posts. Using this model, we assessed the effect of feeding frequency on VBAM cellularity. Feeding 3×/week significantly increased nuclear fraction at multiple tissue depths relative to 2×/day. VBAM maturation was similarly improved in 3×/week feeding as measured by nuclear alignment (23.49° ± 3.644) and nuclear aspect ratio (2.274 ± 0.0643) relative to 2x/day (35.93° ± 2.942) and (1.371 ± 0.1127), respectively. The described techniques are designed to be simple and easy to implement with minimal training or expense, improving access to dense and/or metabolically active 3D cell culture models.

Enhanced peripheral nerve regeneration by mechano-electrical stimulation.

To address limitations in current approaches for treating large peripheral nerve defects, the presented study evaluated the feasibility of functional material-mediated physical stimuli on peripheral nerve regeneration. Electrospun piezoelectric poly(vinylidene fluoride-trifluoroethylene) nanofibers were utilized to deliver mechanical actuation-activated electrical stimulation to nerve cells/tissues in a non-invasive manner. Using morphologically and piezoelectrically optimized nanofibers for neurite extension and Schwann cell maturation based on in vitro experiments, piezoelectric nerve conduits were synthesized and implanted in a rat sciatic nerve transection model to bridge a critical-sized sciatic nerve defect (15 mm). A therapeutic shockwave system was utilized to periodically activate the piezoelectric effect of the implanted nerve conduit on demand. The piezoelectric nerve conduit-mediated mechano-electrical stimulation (MES) induced enhanced peripheral nerve regeneration, resulting in full axon reconnection with myelin regeneration from the proximal to the distal ends over the critical-sized nerve gap. In comparison, a control group, in which the implanted piezoelectric conduits were not activated in vivo, failed to exhibit such nerve regeneration. In addition, at both proximal and distal ends of the implanted conduits, a decreased number of damaged myelination (ovoids), an increased number of myelinated nerves, and a larger axonal diameter were observed under the MES condition as compared to the control condition. Furthermore, unlike the control group, the MES condition exhibited a superior functional nerve recovery, assessed by walking track analysis and polarization-sensitive optical coherence tomography, demonstrating the significant potential of the piezoelectric conduit-based physical stimulation approach for the treatment of peripheral nerve injury.

Metformin activates AMPK and mTOR to Inhibit RANKL-stimulated osteoclast formation.

OBJECTIVE: Metformin is a medication used to treat type 2 diabetes by inhibiting hepatic glucose production through adenosine monophosphate-activated protein kinase (AMPK) activation. Autophagy is closely related to the homeostasis and stress mechanisms of the body. In recent years, much research has arisen on therapeutic methods utilizing autophagy mechanisms to treat diagnoses such as metabolic diseases, tumors, and Alzheimer's disease. This study thus aimed to investigate the effects of metformin treatment on the differentiation of osteoclasts and changes in AMPK mechanisms, which play an important role in regulating energy homeostasis, and mTOR, a highly conserved kinase that regulates autophagy. MATERIALS AND METHODS: Experimentation, including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, tartrate-resistant acid phosphate (TRAP) staining, pit formation assay, immunofluorescence, western blotting, and real-time polymerase chain reaction (PCR) was performed to investigate the effects of metformin on osteoclast differentiation. Additionally, to investigate its association with AMPK and pathways, the AMPK inhibitor compound C and mammalian targets of rapamycin (mTOR) activator leucine were used to examine the expression of osteoclast- or autophagy-related proteins, genes, and TRAP-positive cells. RESULTS: Metformin showed no cytotoxic effects on mouse osteoblastic cell lines (MC3T3-E1) and murine macrophage cell lines (RAW264.7) but did inhibit osteoclast differentiation. Furthermore, metformin was found to inhibit osteoclast differentiation through AMPK activation and mTOR inhibition. In turn, AMPK inhibition using compound C promoted osteoclast differentiation, and mTOR activation using leucine inhibited autophagy and osteoclast differentiation. CONCLUSIONS: Metformin activates the AMPK pathway while functioning as an activator of mTOR, thereby leading to the inhibition of autophagy and osteoclast differentiation.

Passivation effect on Cd0.95Mn0.05Te0.98Se0.02 radiation detection performance.

CdTe-based detectors have the problem of Te-rich surface layers caused by Br etching, which is one of fabrication steps. Te-rich layer acts as a trapping center and serves as an additional source of charge carriers, thereby degrading transport property of charge carriers and enriching leakage current on surface of detector. To solve this problem, we introduced sodium hypochlorite (NaOCl) as a passivant, and investigated its effect on Cd0.95Mn0.05Te0.98Se0.02 (CMTS), by analyzing chemical state of surface and its performance. After passivation with NaOCl, the results of X-ray photoelectron spectroscopy (XPS) shows the formation of tellurium oxide and elimination of water on CMTS surface, and CMTS presented enhanced performance with Am-241 radioisotope. Consequently, it is demonstrated that the passivation with NaOCl reduces leakage current, compensates defect, and elevates transport of charge carriers, thereby decreasing charge loss of carriers and improving performance of CMTS detector.

In Vivo Tumorigenicity of the 20q11.21 Amplicon in an Engraftment Model of hPSCs and Differentiated Liver Cells.

Human pluripotent stem cells (hPSCs) are a promising source of somatic cells for clinical applications and disease modelling. However, during culture they accumulate genetic aberrations such as amplification of 20q11.21 which occurs in approximately 20% of extensively cultured hPSC lines and confers a BCL2L1-mediated survival advantage. During the production of the large number of cells required for transplantation and therapy these aberrations may become unavoidable which has important safety implications for therapies and may also impact upon disease modelling. Presently, these risks are poorly understood; whilst it is apparent that large-scale genetic aberrations can pose an oncogenic risk, the risks associated with smaller, more insidious changes have not been fully explored. In this report, the effects of engraftment of human embryonic stem cells (hESCs) and hESC-derived hepatocyte-like cells (HLCs) with and without amplification of the 20q11.21 minimal amplicon and isochromosome 20q (i20q) in SCID-beige mice are presented. The cells were tracked in vivo using a luminescent reporter over a period of approximately four months. Intrasplenic injection of hESCs showed greater engraftment potential and the formation of more severely disruptive lesions in the liver and spleen of animals injected with cells containing 20q11.21 compared with i20q and wild type. HLCs with 20q11.21 engrafted more successfully and formed more severely disruptive lesions than wild type cells or cells with i20q. These results reinforce the notion that karyotyping of therapeutic hPSC is required for transplant, and suggest that screening for known common aberrations is necessary. Further work to identify commonly arising genetic aberrations should be performed and routine screening for hPSCs intended for therapeutic use should be used.

Interaction between epidermal growth factor receptor and C-C motif chemokine receptor 2 in the ovulatory cascade.

The epidermal growth factor receptor (EGFR) signaling pathway is one of the main pathways responsible for propagating the luteinizing hormone (LH) signal throughout the cumulus cells and the oocyte. Recently, we have proposed the C-C motif chemokine receptor 2 (CCR2) and its main ligand (monocyte chemoattractant protein-1, MCP1) as novel mediators of the ovulatory cascade. Our previous results demonstrate that the gonadotropins (GNT), amphiregulin (AREG), and prostaglandin E2 (PGE2) stimulation of periovulatory gene mRNA levels occurs, at least in part, through the CCR2/MCP1 pathway, proposing the CCR2 receptor as a novel mediator of the ovulatory cascade in a feline model. For that purpose, feline cumulus-oocyte complexes (COCs) were cultured in the presence or absence of an EGFR inhibitor, recombinant chemokine MCP1, and gonadotropins [as an inducer of cumulus-oocyte expansion (C-OE), and oocyte maturation] to further assess the mRNA expression of periovulatory key genes, C-OE, oocyte nuclear maturation, and steroid hormone production. We observed that MCP1 was able to revert the inhibition of AREG mRNA expression by an EGFR inhibitor within the feline COC. In accordance, the confocal analysis showed that the GNT-stimulated hyaluronic acid (HA) synthesis, blocked by the EGFR inhibitor, was recovered by the addition of recombinant MCP1 in the C-OE culture media. Also, MCP1 was able to revert the inhibition of progesterone (P4) production by EGFR inhibitor in the C-OE culture media. Regarding oocyte nuclear maturation, recombinant MCP1 could also revert the inhibition triggered by the EGFR inhibitor, leading to a recovery in the percentage of metaphase II (MII)-stage oocytes. In conclusion, our results confirm the chemokine receptor CCR2 as a novel intermediate in the ovulatory cascade and demonstrate that the EGFR/AREG and the CCR2/MCP1 signaling pathways play critical roles in regulating feline C-OE and oocyte nuclear maturation, with CCR2/MCP1 signaling pathway being downstream EGFR/AREG pathway within the ovulatory cascade.

Changes of antioxidant enzymes in the kidney after cardiac arrest in the rat model.

Globally, cardiac arrest (CA) is a leading cause of death and disability. Asphyxial CA (ACA)-induced kidney damage is a crucial factor in reducing the survival rate. The purpose of this study was to investigate the role of antioxidant enzymes in histopathological renal damage in an ACA rat model at different time points. A total of 88 rats were divided into five groups and exposed to ACA except for the sham group. To evaluate glomerular function and oxidative stress, serum levels of blood urea nitrogen (BUN) and creatinine (Crtn) and malondialdehyde (MDA) levels in renal tissues were measured. To determine histopathological damage, hematoxylin and eosin staining, periodic acid-Schiff staining, and Masson's trichrome staining were performed. Expression levels of antioxidant enzymes including superoxide dismutase-1 (SOD-1), superoxide dismutase-2 (SOD-2), catalase (CAT), and glutathione peroxidase (GPx) were measured by immunohistochemistry (IHC). Survival rate of the experimental rats was reduced to 80% at 6 h, 55% at 12 h, 42.9% at 1 day, and 33% at 2 days after return of spontaneous circulation. Levels of BUN, Crtn, and MDA started to increase significantly in the early period of CA induction. Renal histopathological damage increased markedly from 6 h until two days post-CA. Additionally, expression levels of antioxidant enzymes were significantly decreased at 6 h, 12 h, 1 day, and 2 days after CA. CA-induced oxidative stress and decreased levels of antioxidant enzymes (SOD-1, SOD-2, CAT, GPx) from 6 h to two days could be possible mediators of severe renal tissue damage and increased mortality rate.

Development and evaluation of photon-counting Cd0.875Zn0.125Te0.98Se0.02 detector for measuring bone mineral density.

Cadmium zinc telluride (CZT) has been actively researched and developed by researchers in various fields. In medical applications, especially photon-counting, CZT enables improved image quality, multi-material decomposition, and improved dose efficiency. Moreover, band gap engineering and selenium addition on CZT improved electrical, spectroscopic and structural properties, thereby supporting performance of CZT as a photon-counting detector. In this study, it is shown that Cd0.875Zn0.125Te0.98Se0.02 (CZTS) shows sufficient performance without loss of detection efficiency. We carried out a study involving the application of this CZTS on calculating bone mineral density (BMD) values, because this application has a novelty of new material for BMD sensor which follows the CdTe- or CdZnTe- based BMD detector. Anatomical images from different energy bins contained different information of attenuation although the images were taken in the same region at the same time. Moreover, calculated BMD values had a proper tendency depending on the amount of bone in that region. The final BMD value was 1.1972 g/cm2, which is close to the real value of 1.2 g/cm2. The introduction with a bone filter and a smaller pixel size will improve the accuracy and precision of photon-counting CZTS detectors for measuring BMD values. However, in this study the CZTS showed the feasibility that a photon-counting CZTS detector can help the measurement of BMD values and the diagnosis of osteoporosis.

Changes of antioxidant enzymes in the kidney after cardiac arrest in the rat model

Globally, cardiac arrest (CA) is a leading cause of death and disability. Asphyxial CA (ACA)-induced kidney damage is a crucial factor in reducing the survival rate. The purpose of this study was to investigate the role of antioxidant enzymes in histopathological renal damage in an ACA rat model at different time points. A total of 88 rats were divided into five groups and exposed to ACA except for the sham group. To evaluate glomerular function and oxidative stress, serum levels of blood urea nitrogen (BUN) and creatinine (Crtn) and malondialdehyde (MDA) levels in renal tissues were measured. To determine histopathological damage, hematoxylin and eosin staining, periodic acid-Schiff staining, and Masson's trichrome staining were performed. Expression levels of antioxidant enzymes including superoxide dismutase-1 (SOD-1), superoxide dismutase-2 (SOD-2), catalase (CAT), and glutathione peroxidase (GPx) were measured by immunohistochemistry (IHC). Survival rate of the experimental rats was reduced to 80% at 6 h, 55% at 12 h, 42.9% at 1 day, and 33% at 2 days after return of spontaneous circulation. Levels of BUN, Crtn, and MDA started to increase significantly in the early period of CA induction. Renal histopathological damage increased markedly from 6 h until two days post-CA. Additionally, expression levels of antioxidant enzymes were significantly decreased at 6 h, 12 h, 1 day, and 2 days after CA. CA-induced oxidative stress and decreased levels of antioxidant enzymes (SOD-1, SOD-2, CAT, GPx) from 6 h to two days could be possible mediators of severe renal tissue damage and increased mortality rate.

Development of a Vascularized Human Skin Equivalent with Hypodermis for Photoaging Studies.

Photoaging is an important extrinsic aging factor leading to altered skin morphology and reduced function. Prior work has revealed a connection between photoaging and loss of subcutaneous fat. Currently, primary models for studying this are in vivo (human samples or animal models) or in vitro models, including human skin equivalents (HSEs). In vivo models are limited by accessibility and cost, while HSEs typically do not include a subcutaneous adipose component. To address this, we developed an "adipose-vascular" HSE (AVHSE) culture method, which includes both hypodermal adipose and vascular cells. Furthermore, we tested AVHSE as a potential model for hypodermal adipose aging via exposure to 0.45 ± 0.15 mW/cm2 385 nm light (UVA). One week of 2 h daily UVA exposure had limited impact on epidermal and vascular components of the AVHSE, but significantly reduced adiposity by approximately 50%. Overall, we have developed a novel method for generating HSE that include vascular and adipose components and demonstrated potential as an aging model using photoaging as an example.

Validation of the Anti-Inflammatory Effect of Tenebrio Molitor Larva Oil in a Colitis Mouse Model.

Ulcerative colitis is caused by various external factors and is an inflammatory disease that causes decreased intestinal function. Tenebrio molitor larvae contain more than 30 % fat, and the fat component consists of 45 % oleic acid, 20 % linoleic acid and 20 % polyunsaturated fatty acids. In this study, after administering Tenebrio molitor larva oil (TMLO) in a dextran sodium sulphate (DSS)-induced ulcerative colitis mouse model, the pathological findings and inflammatory markers of colitis were analysed to assess whether a colitis mitigation effect was achieved. In the TMLO-administered group, the colon length increased, the spleen weight decreased, and the body weight increased compared with that in the DSS group. In addition, the disease activity index level decreased, the mRNA expression level of inflammatory cytokines in the colon decreased, and the myeloperoxidase activity level significantly decreased. Also, the activity of the NF-κB pathway involved in the regulation of the inflammatory response was lower in the TMLO group than in the DSS group. Taken together, these results suggest that TMLO suppresses occurrence of acute ulcerative colitis in the DSS mouse model. Therefore, TMLO has the potential to be developed as a health food for the prevention and treatment of ulcerative colitis.

Coordinated cortical thickness alterations across six neurodevelopmental and psychiatric disorders.

Neuropsychiatric disorders are increasingly conceptualized as overlapping spectra sharing multi-level neurobiological alterations. However, whether transdiagnostic cortical alterations covary in a biologically meaningful way is currently unknown. Here, we studied co-alteration networks across six neurodevelopmental and psychiatric disorders, reflecting pathological structural covariance. In 12,024 patients and 18,969 controls from the ENIGMA consortium, we observed that co-alteration patterns followed normative connectome organization and were anchored to prefrontal and temporal disease epicenters. Manifold learning revealed frontal-to-temporal and sensory/limbic-to-occipitoparietal transdiagnostic gradients, differentiating shared illness effects on cortical thickness along these axes. The principal gradient aligned with a normative cortical thickness covariance gradient and established a transcriptomic link to cortico-cerebello-thalamic circuits. Moreover, transdiagnostic gradients segregated functional networks involved in basic sensory, attentional/perceptual, and domain-general cognitive processes, and distinguished between regional cytoarchitectonic profiles. Together, our findings indicate that shared illness effects occur in a synchronized fashion and along multiple levels of hierarchical cortical organization.

Enhanced spectral-domain optical coherence tomography (SD-OCT) using in situ ultrasonic virtual tunable optical waveguides.

A conventional optical lens can enhance lateral resolution in optical coherence tomography (OCT) by focusing the input light onto the sample. However, the typical Gaussian beam profile of such a lens will impose a tradeoff between the depth of focus (DOF) and the lateral resolution. The lateral resolution is often compromised to achieve a mm-scale DOF. We have experimentally shown that using a cascade system of an ultrasonic virtual tunable optical waveguide (UVTOW) and a short focal-length lens can provide a large DOF without severely compromising the lateral resolution compared to an external lens with the same effective focal length. In addition, leveraging the reconfigurability of UVTOW, we show that the focal length of the cascade system can be tuned without the need for mechanical translation of the optical lens. We compare the performance of the cascade system with a conventional optical lens to demonstrate enhanced DOF without compromising the lateral resolution as well as reconfigurability of UVTOW for OCT imaging.

Accelerated Synthetic MRI with Deep Learning-Based Reconstruction for Pediatric Neuroimaging.

BACKGROUND AND PURPOSE: Synthetic MR imaging is a time-efficient technique. However, its rather long scan time can be challenging for children. This study aimed to evaluate the clinical feasibility of accelerated synthetic MR imaging with deep learning-based reconstruction in pediatric neuroimaging and to investigate the impact of deep learning-based reconstruction on image quality and quantitative values in synthetic MR imaging. MATERIALS AND METHODS: This study included 47 children 2.3-14.7 years of age who underwent both standard and accelerated synthetic MR imaging at 3T. The accelerated synthetic MR imaging was reconstructed using a deep learning pipeline. The image quality, lesion detectability, tissue values, and brain volumetry were compared among accelerated deep learning and accelerated and standard synthetic data sets. RESULTS: The use of deep learning-based reconstruction in the accelerated synthetic scans significantly improved image quality for all contrast weightings (P < .001), resulting in image quality comparable with or superior to that of standard scans. There was no significant difference in lesion detectability between the accelerated deep learning and standard scans (P > .05). The tissue values and brain tissue volumes obtained with accelerated deep learning and the other 2 scans showed excellent agreement and a strong linear relationship (all, R 2 > 0.9). The difference in quantitative values of accelerated scans versus accelerated deep learning scans was very small (tissue values, <0.5%; volumetry, -1.46%-0.83%). CONCLUSIONS: The use of deep learning-based reconstruction in synthetic MR imaging can reduce scan time by 42% while maintaining image quality and lesion detectability and providing consistent quantitative values. The accelerated deep learning synthetic MR imaging can replace standard synthetic MR imaging in both contrast-weighted and quantitative imaging.

Magnetic Field-Modulated Plasmonic Scattering of Hybrid Nanorods for FFT-Weighted OCT Imaging in NIR-II.

We report a method for fast Fourier transform (FFT)-weighted optical coherence tomography (OCT) in the second biological tissue transparency window by actively modulating the plasmonic scattering of Fe3O4@Au hybrid nanorods using magnetic fields. Instead of tracking the nanoparticles' lateral displacement in conventional magnetomotive OCT imaging, we monitor the nanorod rotation and optical signal changes under an alternating magnetic field in real time. The coherent rotation of the nanorods with the field produces periodic OCT signals, and the FFT is then used to convert the periodic OCT signals in the time domain to a single peak in the frequency domain. This allows automatic screening of nanorod signals from the random biological noises and reconstruction of FFT-weighted images using a computer program based on a time-sequence image set. Compared with conventional magnetomotive OCT, the FFT-weighted imaging technique creates enhanced OCT images with dB-scale contrast over an order of magnitude higher than the original images.

Sound Induced Vibrations Deform the Organ of Corti Complex in the Low-Frequency Apical Region of the Gerbil Cochlea for Normal Hearing : Sound Induced Vibrations Deform the Organ of Corti Complex.

Human speech primarily contains low frequencies. It is well established that such frequencies maximally excite the cochlea near its apex. But, the micromechanics that precede and are involved in this transduction are not well understood. We measured vibrations from the low-frequency, second turn in intact gerbil cochleae using optical coherence tomography (OCT). The data were used to create spatial maps that detail the sound-evoked motions across the sensory organ of Corti complex (OCC). These maps were remarkably similar across animals and showed little variation with frequency or level. We identify four, anatomically distinct, response regions within the OCC: the basilar membrane (BM), the outer hair cells (OHC), the lateral compartment (lc), and the tectorial membrane (TM). Results provide evidence that active processes in the OHC play an important role in the mechanical interplay between different OCC structures which increases the amplitude and tuning sharpness of the traveling wave. The angle between the OCT beam and the OCC makes that we captured radial motions thought to be the effective stimulus to the mechano-sensitive hair bundles. We found that TM responses were relatively weak, arguing against a role in enhancing mechanical hair bundle deflection. Rather, BM responses were found to closely resemble the frequency selectivity and sensitivity found in auditory nerve fibers (ANF) that innervate the low-frequency cochlea.

Automated epidermal thickness quantification of in vitro human skin equivalents using optical coherence tomography.

Human skin equivalents (HSEs) are in vitro models of human skin. They are used to study skin development, diseases, wound healing and toxicity. The gold standard of analysis is histological sectioning, which both limits three-dimensional assessment of the tissue and prevents live culture monitoring. Optical coherence tomography (OCT) has previously been used to visualize in vivo human skin and in vitro models. OCT is noninvasive and enables real-time volumetric analysis of HSEs. The techniques presented here demonstrate the use of OCT imaging to track HSE epidermal thickness over 8 weeks of culture and improve upon previous processing of OCT images by presenting algorithms that automatically quantify epidermal thickness. Through volumetric automated analysis, HSE morphology can be accurately tracked in real time.

Low-shear modeled microgravity affects metabolic networks of Escherichia coli O157:H7 EDL933: Further insights into space-microbiology consequences.

Escherichia coli O157:H7 EDL933 exposed to low-shear modeled microgravity (LSMMG) and normal gravity (NG) was used for a transcriptomic analysis. The modified Gompertz model (R2 = 0.81-0.99) showed an increased growth rate of E. coli O157:H7 under LSMMG. The mechanism of this active growth was associated with highly upregulated genes in nutrient and energy metabolism, including the TCA cycle, glycolysis, and pyruvate metabolism. Green fluorescent protein-labeled E. coli O157:H7 also formed significantly thick biofilms (fluorescent unit: NG, 1,263; LSMMG, 1,533; P = 0.0473) under LSMMG, whereas bacterial mobility decreased slightly (P = 0.0310). The transcriptomic analysis revealed that genes encoding glycogen biosynthesis (glgCAP operon) were upregulated (1.40 to 1.82 of log fold change [FC]) due to the downregulation of csrA (2.17 of log FC), which is the global regulator of biofilm formation of E. coli. We also identified 52 genes in E. coli O157:H7 EDL933 that were involved in the secretion pathway, 32 of which showed ≥2-fold significant changes in transcription levels after cultivation under LSMMG. Notably, all downregulated genes belonged to the type III and VI secretion systems, indicating that host cell contact secretion was dysregulated in the LSMMG cultures compared to the NG cultures. LSMMG also stimulates the pathogenicity of E. coli O157:H7 via transcriptional upregulation of Shiga toxin 1 (1.36 to 2.81 log FC) and toxin HokB (6.1 log FC). Our results suggest LSMMG affects bacterial growth, biofilm formation, and E. coli O157:H7 pathogenicity at some transcriptional levels, which indicates the importance of understanding biological consequences.