Peptide-induced formation of a tethered lipid bilayer membrane on mesoporous silica.

Tethered bilayer lipid membranes (tBLMs) on solid supports have substantial advantages as models of artificial cell membranes for such biomedical applications as drug delivery and biosensing. Compared with untethered lipid membranes, tBLMs have more space between substrate and the bilayer and greater stability. The purpose of this work was to use these properties to fabricate and characterize a zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid tBLM containing 2 mol% 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-maleimide(poly(ethylene glycol))-2000 (DSPE-PEG2000-NHS) lipid tethers on a 3-aminopropyltrimethoxysilane-modified mesoporous silica substrate. A quartz crystal microbalance with dissipation monitoring was used to monitor the process of vesicle adsorption and tBLM self-assembly, and atomic force microscopy was performed to characterize the structural properties of the tBLM obtained. Whereas tether-containing lipid vesicles ruptured neither spontaneously nor as a result of osmotic shock, introduction of an amphipathic α-helical (AH) peptide induced vesicle rupture and subsequent tBLM formation. Taken together, our findings suggest that the AH peptide is an efficient means of rupturing vesicles of both simple and complex composition, and is, therefore, useful for formation of tBLMs on solid and mesoporous materials for applications in biotechnology.

Elucidating how bamboo salt interacts with supported lipid membranes: influence of alkalinity on membrane fluidity.

Bamboo salt is a traditional medicine produced from sea salt. It is widely used in Oriental medicine and is an alkalizing agent with reported antiinflammatory, antimicrobial and chemotherapeutic properties. Notwithstanding, linking specific molecular mechanisms with these properties has been challenging to establish in biological systems. In part, this issue may be related to bamboo salt eliciting nonspecific effects on components found within these systems. Herein, we investigated the effects of bamboo salt solution on supported lipid bilayers as a model system to characterize the interaction between lipid membranes and bamboo salt. The atomic composition of unprocessed and processed bamboo salts was first analyzed by mass spectrometry, and we identified several elements that have not been previously reported in other bamboo salt preparations. The alkalinity of hydrated samples was also measured and determined to be between pH 10 and 11 for bamboo salts. The effect of processed bamboo salt solutions on the fluidic properties of a supported lipid bilayer on glass was next investigated by fluorescence recovery after photobleaching (FRAP) analysis. It was demonstrated that, with increasing ionic strength of the bamboo salt solution, the fluidity of a lipid bilayer increased. On the contrary, increasing the ionic strength of near-neutral buffer solutions with sodium chloride salt diminished fluidity. To reconcile these two observations, we identified that solution alkalinity is critical for the effects of bamboo salt on membrane fluidity, as confirmed using three additional commercial bamboo salt preparations. Extended-DLVO model calculations support that the effects of bamboo salt on lipid membranes are due to the alkalinity imparting a stronger hydration force. Collectively, the results of this work demonstrate that processing of bamboo salt strongly affects its atomic composition and that the alkalinity of bamboo salt solutions contributes to its effect on membrane fluidity.

Solvent-assisted lipid bilayer formation on silicon dioxide and gold.

Planar lipid bilayers on solid supports mimic the fundamental structure of biological membranes and can be investigated using a wide range of surface-sensitive techniques. Despite these advantages, planar bilayer fabrication is challenging, and there are no simple universal methods to form such bilayers on diverse material substrates. One of the novel methods recently proposed and proven to form a planar bilayer on silicon dioxide involves lipid deposition in organic solvent and solvent exchange to influence the phase of adsorbed lipids. To scrutinize the specifics of this solvent-assisted lipid bilayer (SALB) formation method and clarify the limits of its applicability, we have developed a simplified, continuous solvent-exchange version to form planar bilayers on silicon dioxide, gold, and alkanethiol-coated gold (in the latter case, a lipid monolayer is formed to yield a hybrid bilayer) and varied the type of organic solvent and rate of solvent exchange. By tracking the SALB formation process with simultaneous quartz crystal microbalance-dissipation (QCM-D) and ellipsometry, it was determined that the acoustic, optical, and hydration masses along with the acoustic and optical thicknesses, measured at the end of the process, are comparable to those observed by employing conventional fabrication methods (e.g., vesicle fusion). As shown by QCM-D measurements, the obtained planar bilayers are highly resistant to protein adsorption, and several, but not all, water-miscible organic solvents could be successfully used in the SALB procedure, with isopropanol yielding particularly high-quality bilayers. In addition, fluorescence recovery after photobleaching (FRAP) measurements demonstrated that the coefficient of lateral lipid diffusion in the fabricated bilayers corresponds to that measured earlier in the planar bilayers formed by vesicle fusion. With increasing rate of solvent exchange, it was also observed that the bilayer became incomplete and a phenomenological model was developed in order to explain this feature. The results obtained allowed us to clarify and discriminate likely steps of the SALB formation process as well as determine the corresponding influence of organic solvent type and flow conditions on these steps. Taken together, the findings demonstrate that the SALB formation method can be adapted to a continuous solvent-exchange procedure that is technically minimal, quick, and efficient to form planar bilayers on solid supports.

Complete mitochondrial genome of the southern painted turtle (Chrysemys dorsalis, Testudines: Emydidae) in Korea.

The complete mitochondrial genome of Chrysemys dorsalis in Korea was sequenced and characterized. The mitochondrial genome is 17,258 bp in length and the GC content is 39%. It is constituted of 37 genes, 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a noncoding region. Phylogenetic analysis reveals that C. dorsalis forms a monophyletic group with C. picta turtles but is distinctly separated from them, aligning with previous findings. In Korea, C. dorsalis forms a discrete clade, separate from both native and invasive turtle species. No evidence of genetic disturbance or intermingling is observed. This is the first case of a complete mitochondrial genome from C. dorsalis and provides crucial data for understanding C. dorsalis and managing invasive species effectively, emphasizing the need for continued mitochondrial genome data accumulation.

Influence of osmotic pressure on adhesion of lipid vesicles to solid supports.

The adhesion of lipid vesicles to solid supports represents an important step in the molecular self-assembly of model membrane platforms. A wide range of experimental parameters are involved in controlling this process, including substrate material and topology, lipid composition, vesicle size, solution pH, ionic strength, and osmotic pressure. At present, it is not well understood how the magnitude and direction of the osmotic pressure exerted on a vesicle influence the corresponding adsorption kinetics. In this work, using quartz crystal microbalance with dissipation (QCM-D) monitoring, we have experimentally studied the role of osmotic pressure in the adsorption of zwitterionic vesicles onto silicon oxide. The osmotic pressure was induced by changing the ionic strength of the solvent across an appreciably wider range (from 25 to 1000 mM NaCl outside of the vesicle, and 125 mM NaCl inside of the vesicle, unless otherwise noted) compared to that used in earlier works. Our key finding is demonstration that, by changing osmotic pressure, all three generic types of the kinetics of vesicle adsorption and rupture can be observed in one system, including (i) adsorption of intact vesicles, (ii) adsorption and rupture after reaching a critical vesicle coverage, and (iii) rupture just after adsorption. Furthermore, theoretical analysis of pressure-induced deformation of adsorbed vesicles and a DLVO-type analysis of the vesicle-substrate interaction qualitatively support our observations. Taken together, the findings in this work demonstrate that osmotic pressure can either promote or impede the rupture of adsorbed vesicles on silicon oxide, and offer experimental evidence to support adhesion energy-based models that describe the adsorption and spontaneous rupture of vesicles on solid supports.

Prophylactic intraoperative wound irrigation with antibiotic solution for the prevention of surgical incisional wound infections: Systematic literature review and meta-analysis.

BACKGROUND: There is no consensus on the use of prophylactic intraoperative wound irrigation (pIOWI) for reducing surgical-site infections (SSIs), particularly surgical incisional wounds, and opinions are divided on whether an antibiotic should be mixed with the solution used for incisional wound irrigation. No large, reliable cohort studies or meta-analyses of pIOWI for surgical incisional wounds were found in PubMed or Embase. METHODS: We searched the PubMed, Embase, Cochrane Library, Insight, Scopus, and Web of Science databases for primary research articles investigating the relevance of pIOWI with antibiotics for SSIs. The initial search was limited to human studies published before January 2022, which were indexed as randomized controlled trials (RCTs); clinical trials; or observational, cross-sectional, or cohort studies. We used R statistical software version 4.1.2 for this meta-analysis. RESULTS: The odds ratio of the random-effects model was 0.519 [95% confidence interval (CI); 0.311, 0.864, P-value < 0.0117], indicating that the intervention had a statistically significant effect on surgical complications. To examine the heterogeneity of the entire study, we performed statistical analysis (τ2 (tau square) = 0.4175 [0.0732; 2.8178]; τ (tau) = 0.6461 [0.2706; 1.6786]; Higgins' I2 = 64.0% [34.8%; 80.1%]; and H = 1.67 [1.24; 2.24]). CONCLUSIONS: Many studies have shown that inclusion of antibiotics in the irrigation solution significantly lowers the rate of soft-tissue-related SSIs, but those studies contain both heterogeneity and many biases. Further large, prospective RCTs only limited to incisional SSIs and excluding other variables and biases in the field of plastic surgery are needed.

Age Group Classification of Dental Radiography without Precise Age Information Using Convolutional Neural Networks.

Automatic age estimation using panoramic dental radiographic images is an important procedure for forensics and personal oral healthcare. The accuracies of the age estimation have increased recently with the advances in deep neural networks (DNN), but DNN requires large sizes of the labeled dataset which is not always available. This study examined whether a deep neural network is able to estimate tooth ages when precise age information is not given. A deep neural network model was developed and applied to age estimation using an image augmentation technique. A total of 10,023 original images were classified according to age groups (in decades, from the 10s to the 70s). The proposed model was validated using a 10-fold cross-validation technique for precise evaluation, and the accuracies of the predicted tooth ages were calculated by varying the tolerance. The accuracies were 53.846% with a tolerance of ±5 years, 95.121% with ±15 years, and 99.581% with ±25 years, which means the probability for the estimation error to be larger than one age group is 0.419%. The results indicate that artificial intelligence has potential not only in the forensic aspect but also in the clinical aspect of oral care.

The Donut DIEP Flap: A Novel Scarless Technique.

Deep inferior epigastric perforator (DIEP) flap surgery is a common technique for breast reconstruction. However, the long and noticeable abdominal scarring is one of its greatest disadvantages. Here, we suggest a minimal scarring DIEP flap harvest with a novel abdominal design. The key to this method is to preserve more skin tissue with a circular design centered around the navel. Three circular incisions are made: (1) the smallest circle represents an incision around the umbilicus; (2) the middle circle with a radius of <3.5 cm indicates skin incision because the donut-like skin paddle between the small and middle circles is included in the flap; (3) the largest circle with a radius of >10 cm represents the extent of flap dissection that was done diagonally from the skin toward the Scarpa's fascia. Pedicle dissection is proceeded with the conventional method. For closure, a purse-string suture is performed with the umbilicus at its center leaving only a single small circular scar around the umbilicus as the final scar. Closure of the donor-site is possible with the patient in a supine or slightly flexed position due to less skin excision. LEVEL OF EVIDENCE: Therapeutic, V.

Late reconstruction of post-traumatic enophthalmos and hypoglobus using three-dimensional implants: a case series.

Post-traumatic enophthalmos and hypoglobus are common sequelae of facial bone fractures, even after reduction surgery. They are associated with functional and esthetic issues, which may lower the quality of life. These deformities frequently present late, and adequate correction is difficult. We report three cases of late inferior orbital rim reconstructions with three-dimensional printed implants to help resolve these problems. The average duration between the traumatic event and surgery was 3 years and 4 months. One patient was treated with a completely absorbable implant and exhibited satisfactory results until the implant started to biodegrade at 1 year and 9 months after surgery. Two patients were treated with a permanent implant and demonstrated satisfactory results. However, longer follow-up periods were needed. There were no complications such as infection, diplopia, or restriction of ocular motion and the patients were satisfied with the esthetic results.

Cranioplasty and temporal hollowing correction with a three-dimensional printed bioresorbable mesh and double vertical suture anchor muscle sling: a case report.

Postoperative temporal hollowing is a common complication of craniotomy. Damage and repositioning of the temporalis muscle can lead to a depression in the temporal side of the skull with inferior bulging, worsening aesthetic outcomes. We report a case of cranioplasty with three-dimensional (3D) printed mesh involving an additional correction using a temporalis muscle sling to help address this problem. A 3D-printed bioabsorbable mesh was prepared based on preoperative facial computed tomography, and was fixed to the hollowed area for tissue augmentation. The temporalis muscle was elevated and fanned out to its original position, and a sling was attached to a screw that was fixed to the mesh. For reinforcement, an additional sling was attached to another screw fixed to the mesh 2-3 cm vertically above the first screw. Aesthetic results were confirmed immediately after surgery and later during outpatient follow-up. Both depression and lateral bulging were resolved, and there was no delayed drooping of the temporalis muscle on 6-month follow-up. There were no complications, and the patient was satisfied with the appearance. This is a simple yet effective technique with a low risk of complications, and should be considered for postoperative temporal hollowing patients, especially those with severe lateral bulging.

Risk assessment for the native anurans from an alien invasive species, American bullfrogs (Lithobates catesbeianus), in South Korea.

The invasive species are of global concern, and the Invasive American Bullfrog (IAB; Lithobates catesbeianus) is one of the worst invasive amphibian species worldwide. Like other countries, South Korea is also facing challenges from IAB. Although many studies indicated impacts of IAB on native anurans in Korea, the actual risk at the specific level is yet to evaluate. Considering the putative invasiveness of IAB, it is hypothesized that any species with the possibility of physical contact or habitat sharing with them, will have a potential risk. Thus, we estimated and observed their home range, preferred habitats, morphology, behavior, and ecology. Then, comparing with existing knowledge, we assessed risks to the native anurans. We found a home range of 3474.2 ± 5872.5 m2 and identified three types of habitats for IAB. The analyses showed at least 84% of native anurans (frogs and toads) were at moderate to extreme risks, which included all frogs but only 33% of toads. Finally, we recommended immediate actions to conserve the native anurans based on our results. As this study is the first initiative to assess the specific risk level from the invasiveness of L. catesbeianus, it will help the managers to set conservation priorities and strategies.

Hydrogel Stamping for Rapid, Multiplexed, Point-of-Care Immunostaining of Cells and Tissues.

In the era of precision oncology, multicolor fluorescence imaging has become a core technology for multiplexed molecular analysis of cellular and tissue specimens. However, conventional solution-based staining is labor-intensive and time-consuming and requires considerable expertise to yield optimal results, which creates difficulties for employing this technology in resource-limited settings. Here, we report a new immunostaining method based on hydrogel stamping, which is simple, fast, easy to use, and reproducible. We showed that a hydrophilic hydrogel stamp could effectively transfer fluorescent antibodies to targets and withdraw an excess solution when the reaction is completed, obviating the need for extra washing. This unique property allows for quality immunostaining in 5 min for cells using one-eighth of antibody consumption compared to the conventional solution-based method. Furthermore, we implemented fluorescence quenching and immunocycling with hydrogel staining for multiplexed analysis of 9 protein markers at a single cell level. Finally, we applied the immunocycling method to human breast cancer tissue samples and showed quality immunostaining over a large area (∼2 cm2) in 30 min for molecular subtyping of breast cancer. The hydrogel immunostaining could open new opportunities for rapid, automated, and multiplexed profiling in compact point-of-care systems for molecular cancer diagnosis.

Complete mitochondrial genome of the distinct red-eared slider (Trachemys scripta ssp., Testudines: Emydidae) in Korea.

The complete mitochondrial (mt) genome of Trachemys scripta ssp. in Korea was sequenced and characterized. The mt genome is constituted of 37 genes (13 protein-coding genes, 22 transfer RNA genes and 2 ribosomal RNA genes) and a control region. Phylogenetic analysis based on the complete mt genome showed that the unidentified turtle had the mt genome closely related to that of T. s. elegans, though it had distinct morphology compared to T. s. elegans. This study can provide information for biogeographical studies and management plan for invasive species.

Complete mitochondrial genome of the Cumberland slider (Trachemys scripta troostii, Testudienes: Emydidae) in Korea.

The complete mitochondrial (mt) genome of Trachemys scripta troostii was sequenced and was characterized, which comprised 37 genes (13 protein-coding genes, 22 transfer RNAs, and 2 ribosomal RNAs) and a non-coding control region. Phylogenetic analysis based on the full mt genome indicated that T. s. troostii was more closely related to T. scripta from Canada than to T. s. elegans from China or T. s. scripta fom China. This is the first complete mt genome from T. s. troostii, which provides data for further study of phylogeny in Emydidae.

Bacillus velezensis CE 100 Inhibits Root Rot Diseases (Phytophthora spp.) and Promotes Growth of Japanese Cypress (Chamaecyparis obtusa Endlicher) Seedlings.

Root rot diseases, caused by phytopathogenic oomycetes, Phytophthora spp. cause devastating losses involving forest seedlings, such as Japanese cypress (Chamaecyparis obtusa Endlicher) in Korea. Plant growth-promoting rhizobacteria (PGPR) are a promising strategy to control root rot diseases and promote growth in seedlings. In this study, the potential of Bacillus velezensis CE 100 in controlling Phytophthora root rot diseases and promoting the growth of C. obtusa seedlings was investigated. B. velezensis CE 100 produced ß-1,3-glucanase and protease enzymes, which degrade the ß-glucan and protein components of phytopathogenic oomycetes cell-wall, causing mycelial growth inhibition of P. boehmeriae, P. cinnamomi, P. drechsleri and P. erythoroseptica by 54.6%, 62.6%, 74.3%, and 73.7%, respectively. The inhibited phytopathogens showed abnormal growth characterized by swelling and deformation of hyphae. B. velezensis CE 100 increased the survival rate of C. obtusa seedlings 2.0-fold and 1.7-fold compared to control, and fertilizer treatment, respectively. Moreover, B. velezensis CE 100 produced indole-3-acetic acid (IAA) up to 183.7 mg/L, resulting in a significant increase in the growth of C. obtusa seedlings compared to control, or chemical fertilizer treatment, respectively. Therefore, this study demonstrates that B. velezensis CE 100 could simultaneously control Phytophthora root rot diseases and enhance growth of C. obtusa seedlings.

Robotic DIEP Flap Harvest through a Totally Extraperitoneal Approach Using a Single-Port Surgical Robotic System.

SUMMARY: Deep inferior epigastric artery perforator (DIEP) flap surgery is one of the most common techniques for breast reconstruction using abdominal tissue. Although the DIEP flap reduces donor-site morbidity when compared with the conventional free transverse rectus abdominis musculocutaneous flap, violation of the anterior rectus sheath, rectus muscle, and motor nerves cannot be avoided. To further minimize tissue damage in the donor site, the use of a surgical robotic system for DIEP flap harvest with a totally extraperitoneal approach has been suggested. This totally extraperitoneal approach has a long learning curve because of the narrow preperitoneal space and the difficulty of converting a potential space to an actual space. Thus, the authors suggest a single-port robotic system optimized for narrow surgical spaces as a feasible option for DIEP flap harvest by a totally extraperitoneal approach, which has a shorter learning curve.

The Role of Lysobacter antibioticus HS124 on the Control of Fall Webworm (Hyphantria cunea Drury) and Growth Promotion of Canadian Poplar (Populus canadensis Moench) at Saemangeum Reclaimed Land in Korea.

Populus canadensis Moench forests established in Saemangeum-reclaimed land have been invaded by Hyphantria cunea Drury, causing defoliation and stunted growth. This study investigated the biocontrol potential of cuticle degrading chitinase and protease secreted by Lysobacter antibioticus HS124 against H. cunea larvae. In addition, L. antibioticus HS124 was examined for indole-3-acetic acid phytohormone production for plant growth promotion. To determine the larvicidal activity in the laboratory experiments, crude enzymes, bacteria culture, CY medium, and water (control) were sprayed on the larvae reared on natural diet in insect rearing dishes. Treatment with crude enzymes and bacteria culture caused 76.7% and 66.7% larvae mortality, respectively. The larvae cuticle, mainly composed of chitin and proteins, was degraded by cuticle-degrading enzymes, chitinase, and protease in both the bacteria culture and crude enzyme treatments, causing swelling and disintegration of the cuticle. Field application of the bacteria culture was achieved by vehicle-mounted sprayer. Bacterial treatment caused morphological damage on the larvae cuticles and subsequent mortality. Foliar application of the bacteria culture reduced tree defoliation by H. cunea and enhanced growth compared to the control. Especially, L. antibioticus HS124 produced auxins, and increased growth of poplar trees.

Hydrogel-Based Stamping Technology for Solution-Free Blood Cell Staining.

An accurate microscopical analysis of blood smears requires a reproducible and convenient method of staining. Solution-based staining procedures can be cumbersome. Especially in low- and middle-income countries, the lack of skilled technicians and adequate laboratory facilities, as well as insufficient water and reagent quality, often become confounding factors. To overcome these obstacles, we developed a new cell staining method based on sequential stamping of agarose gel patches that contain eosin, methylene blue/oxidized methylene blue, Azure B, and buffer, respectively. Our method, termed "hydrogel staining", provides a simple, reproducible, solution-free, and inexpensive approach to stain blood cells. We have optimized incubation times to achieve the optimal transfer of dyes to fixed blood cells on a glass slide, with outcomes comparable to conventional solution-based methods for white blood cells and malaria-infected red blood cells. This hydrogel staining method does not require special skills to produce excellent quality stained blood film slides. The new method could enhance the accuracy of microscopical examination of blood smears, especially in resource-limited settings.

Complete mitochondrial genome of the Small Salamander in Korea, Hynobius unisacculus (Anura: Hynobiidae).

The complete mitochondrial (mt) genome of Hynobius unisacculus was sequenced and characterized. The circular mt genome constituted of 37 genes (13 protein-coding genes, 22 transfer RNAs, and 2 ribosomal RNAs) and a non-coding region (NCR). Phylogenetic analysis based on the full mt genome sequences confirmed that H. unisacculus was closely related to Hynobius leechii rather than other Hynobius species. This is the first completed mt genome from H. unisacculus, which provides data for further study of phylogeny in Hynobiidaes.

Effect of induced hyperopia on fall risk and Fourier transformation of postural sway.

BACKGROUND AND PURPOSE: Fall accidents are a social challenge in Korea and elsewhere. Most previous studies have focused on the effects of reduced visual acuity due to myopia on falls and body balance. The objective of this study was to investigate whether uncorrected hyperopia was a major risk factor for falls and to establish whether the risk of falls was absolutely correlated with visual acuity. METHODS: Fifty-one young subjects with a mean age of 22.75 ± 2.13 years were enrolled in this study. To induce hyperopic and myopic refractive errors, spherical lenses of ±1.0-6.0 D (1.0 D stepwise) were used. Under each induced condition, fall risk index and sway power were assessed via Fourier transformation of postural sway using a TETRAX system. RESULTS: The fall risk index for eyes-closed was significantly greater than that of eyes-open with full correction (t = -5.876, p < 0.05). The fall risk index increased significantly from hyperopia induced with -4.0 D lenses (with visual acuity of 0.69 ± 0.32) compared to eyes-open with full correction (F = 3.213, p < 0.05). However, there was no significant change in the induced myopia conditions, despite a drastic decline in decimal visual acuity. Sway power increased significantly in the low-to-medium frequency band derived from the peripheral vestibular system when hyperopia was induced. A significant difference was detected in hyperopia induced with -6.0 D lenses compared to eyes-open with full correction (F = 4.981, p = 0.017). CONCLUSION: An uncorrected hyperopia rather than myopia may increase the risk of falls, although eyes may show normal visual acuity due to the inherent accommodation mechanism. Our findings suggest that the corrected state of refractive errors is more important than the level of visual acuity as the criteria for appropriate visual input, which contributes to stable posture. Therefore, clinicians should consider the refractive condition, especially the characteristics of hyperopia, when analyzing body balance, and appropriate correction of uncorrected hyperopia to prevent falls.