Fabrication of porous poly(L-lactide-co-ε-caprolactone) micropowder for microbubble effect and ultrasound-mediated drug delivery.

Biodegradable elastic poly(L-lactide-co-ε-caprolactone) (PLCL) copolymer (50:50, lactide:caprolactone molar ratio) was synthesized and porous PLCL micropowders was fabricated by a simple method involving rapid cooling of 0.1, 0.5, and 1% (wt/vol) PLCL/dioxane spray into liquid nitrogen. The physicochemical properties of the porous PLCL micropowders were examined by measuring their pore size, pore morphology, and microbead size using a scanning electron microscopy (SEM) and dye and temozolomide (TMZ)-release testing under ultrasound. Human U-87MG, glioblastoma (GBM) cell culture tests were performed to evaluate cell cytotoxicity by released drug from PLCL micropowders. In this study, the porous PLCL micropowders prepared from 1 wt%/vol% PLCL solutions showed a highly porous structure, satisfactory mechanical properties, and optimal drug release efficiency compared with those produced from 0.1 or 0.5 wt%/vol% solutions. The results of the accumulated release test with the results of the absorbance of the dye initially applied, it was confirmed that more than 80% of the added dye was trapped inside the micropowder, and clearly GBM cytotoxicity effect could be observed by the released TMZ. The drug release system using micropowders and ultrasound can be applied as a drug supply system for various diseases such as brain tumors with low drug permeability.

PARVB and HSD17B13 variants are associated with nonalcoholic fatty liver disease in children.

BACKGROUND AND AIM: The aim of this study was to investigate the comprehensive genetic effects of exploratory variants of LYPLAL1, GCKR, HSD17B13, TRIB1, APOC3, MBOAT7, and PARVB on pediatric nonalcoholic fatty liver disease in addition to the previously reported variants of TM6SF2, PNPLA3, and SAMM50 in Korean children. METHODS: A prospective case-control study was conducted involving 309 patients diagnosed using ultrasound and 339 controls. Anthropometric measurements, liver function tests, and metabolic marker analysis were conducted, and fibrosis scores were calculated. Transient elastography was performed in 69 some patients with nonalcoholic fatty liver disease. TaqMan allelic discrimination assays were used for genotyping. The genetic risk scores were calculated using significant variants, namely, HSD17B13, PARVB, PNPLA3, SAMM50, and TM6SF2, to evaluate the additive effect. RESULTS: Risk allele carriers of the PARVB variant showed significantly higher levels of aminotransferases, gamma-glutamyl transferase, alkaline phosphatase, pediatric nonalcoholic fatty liver disease fibrosis score, and aspartate aminotransferase/platelet ratio index. Individuals with a homozygous variant of HSD17B13 showed significantly lower levels of aminotransferase, gamma-glutamyl transferase, liver stiffness measurement, and aspartate aminotransferase/platelet ratio index than those with other genotypes. These parameters did not significantly differ among other variants of LYPLAL1, GCKR, TRIB1, APOC3, and MBOAT7. The genetic risk scores was identified as an independent risk factor for nonalcoholic fatty liver disease and had a positive association with severity. CONCLUSION: HSD17B13 has protective effects on the severity of pediatric nonalcoholic fatty liver disease. Variants of HSD17B13, PARVB, PNPLA3, SAMM50, and TM6SF2 had an additive effect on nonalcoholic fatty liver disease.

Long-Term Pulmonary Function Postspinal Cord Injury.

OBJECTIVE: To investigate mean values of pulmonary function tests (PFT) at specific time points to assess long-term progression in patients with spinal cord injury (SCI). DESIGN: Retrospective cohort study from 1997-2022. SETTING: National rehabilitation hospital, providing scheduled admission for potential SCI-related issues. Follow-up assessments are recommended annually, guiding the observation period into consecutive 1-year intervals. PARTICIPANTS: This study included 1394 adult patients who were admitted at least twice to the National Rehabilitation Center between 1997 and 2022, selected from an initial pool of 1510. Overall, 116 patients were excluded owing to the absence of any PFT results. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Changes in PFT values over time, specifically assessing for a potential 2-phase pattern after injury. The hypothesis that PFT values would initially improve before declining was formulated based on existing literature. RESULTS: Significant changes in pulmonary function were noted among 1394 adults with SCI. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) initially increased within the first 1-2 years after injury but declined to below baseline levels after 6 years. Pronounced changes occurred between <1 year and 1-2 years after injury (FVC: Δ=4.89, SE=0.87, P<.001; FEV1: Δ=4.28, SE=1.09, P=.002) and 1-2 years to >6 years (FVC: Δ= -5.83, SE=0.94, P<.001; FEV1: Δ= -6.49, SE=1.18, P<.001). No significant changes in the FEV1/FVC ratio. Motor completeness was significantly associated with the increase and decline phase, showing a steeper increase and less decline compared with the motor-incomplete group. CONCLUSIONS: Pulmonary function in SCI initially increases but declines over time, falling below initial levels by 6 years. Further evaluation with more complete datasets is warranted to elucidate the factors influencing these changes.

Characteristics of chronic enteropathy associated with SLCO2A1 gene (CEAS) in children, a unique type of monogenic very early-onset inflammatory bowel disease.

BACKGROUND:  Chronic enteropathy associated with SLCO2A1 gene (CEAS) is a unique type of inflammatory bowel disease. CEAS is monogenic disease and is thought to develop from childhood, but studies on pediatric CEAS are scarce. We analyzed characteristics of pediatric CEAS. METHODS: Eleven patients diagnosed with CEAS at Seoul National University Children's Hospital were identified and analyzed. Clinical data of patients were collected. Sanger sequencing of SLCO2A1 was performed on all patients. RESULTS: Patients were diagnosed at a median age of 16.0 years (IQR 11.0 ~ 20.0), and the median age at symptoms onset was only 4.0 years (IQR 2.5 ~ 6.0). Growth delay was observed at the time of diagnosis. Patients showed multiple ulcers or strictures in the small intestine, while the esophagus and colon were unaffected in any patients. Almost half of the patients underwent small intestine resection. The major laboratory features of pediatric CEAS include iron deficiency anemia (IDA), hypoalbuminemia, and near-normal levels of C-reactive protein (CRP). Two novel mutations of SLCO2A1 were identified. The most prevalent symptoms were abdominal pain and pale face. None of the immunomodulatory drugs showed a significant effect on CEAS. CONCLUSIONS: Pediatric CEAS typically develop from very young age, suggesting it as one type of monogenic very early onset inflammatory bowel disease. CEAS can cause growth delay in children but there is no effective treatment currently. We recommend screening for SLCO2A1 mutations to pediatric patients with chronic IDA from a young age and small intestine ulcers without elevation of CRP levels.

Molecular signatures diversity unveiled through a comparative transcriptome analysis of longissimus dorsi and psoas major muscles in Hanwoo cattle.

This study investigates the transcriptome-level alterations that influence production traits and early fattening stage myogenesis in Hanwoo cattle, specifically focusing on the highly prized Longissimus dorsi (LD) and Psoas major (PM) skeletal muscles, which hold significant commercial value. We conducted RNA sequencing analysis on LD and PM muscles from 14 Hanwoo steers (n = 7, each group) at the age of 10 months, all fed the same diet. Our results unveiled a total of 374 and 206 up-regulated differentially expressed genes (DEGs) in LD and PM muscles, respectively, with statistical significance (p < 0.05) and a log2fold change ≥ 1. Genes governing muscle development processes, such as PAX3, MYL3, COL11A1, and MYL6B, were found to be expressed at higher levels in both tissues. Conversely, genes regulating lipid metabolism, including FABP3, FABP4, LEP, ADIPOQ, and PLIN1, exhibited higher expression in the PM muscle. Functional enrichment analysis revealed a tissue-specific response, as PM muscle showed increased lipid metabolism allied pathways, including the PPAR signaling pathway and regulation of lipolysis in adipocytes, while LD was characterized by growth and proliferative processes. Our findings validate the presence of a muscle-dependent transcription and co-expression pattern that elucidates the transcriptional landscape of bovine skeletal muscle.

Below-knee amputation with an ultrasonic scalpel: evaluation of early postoperative clinical outcomes.

OBJECTIVE: Despite the development of microscopic reconstructive techniques for lower limb salvage, major limb amputation is still required for critical, unsalvageable lower leg wounds, with steadily increasing estimates of major limb amputations. In this study, the authors highlight a surgical technique for below-knee (BK) amputation using an ultrasonic scalpel, and evaluate its safety and effectiveness compared with the conventional method of using surgical blades. METHOD: A retrospective chart review was conducted at the Department of Plastic and Reconstructive Surgery, St. Vincent's Hospital, Republic of Korea, on patients who underwent BK amputation between October 2012 and January 2021. Patients were assigned to two groups: amputation using classical methods, such as surgical blades and electrocautery (group A); and amputation using an ultrasonic scalpel (group B). Numerous perioperative factors, such as operation time, intraoperative blood loss, postoperative complications and recovery time were examined. The present study adhered to the STROBE guidelines. RESULTS: A total of 41 patients (16 in group A and 25 in group B) were included in this study. Operation time was significantly shorter in group B (p=0.001) and intraoperative blood loss was lower (p=0.011). Wound healing time did not vary between groups. CONCLUSION: In this study, the use of an ultrasonic scalpel for lower limb amputation was effective in reducing operation time and blood loss, which may be helpful in improving outcomes for patients with comorbidities.

High-Performance Hydroxide Exchange Membrane Fuel Cell Comprising an Atomic Layer-Deposited Silver Cathode.

Atomic layer deposition (ALD) is emerging as an efficient tool for the precise manufacture of catalysts, owing to its sophisticated surface tailoring capabilities. To overcome the techno-economic limitations of fuel cell electric vehicles (FCEVs), which are considered suitable alternatives to battery electric vehicles (BEVs), the development of cost-efficient high-performance catalysts is essential. In this study, we successfully fabricated a Pt-free cathode for a hydroxide exchange membrane fuel cell (HEMFC) with excellent oxygen reduction activity under extremely low loading of Ag electrocatalysts using ALD. Microstructural analysis confirmed that the surface modification by ALD-Ag nanoparticles exhibited excellent step coverage characteristics on porous carbon nanotubes (CNTs). An HEMFC comprising a CNT cathode surface-decorated with ALD-Ag nanoparticles delivered a high peak power density of 2154 mW mgAg-1 in an alkaline environment at 65 °C. This study demonstrates the applicability of ALD for the manufacture of highly active low-cost electrocatalysts for high-performance HEMFCs.

Novel Benchmark Values for Open Major Anatomic Liver Resection in Non-cirrhotic Patients: A Multicentric Study of 44 International Expert Centers.

OBJECTIVE: This study aims at establishing benchmark values for best achievable outcomes following open major anatomic hepatectomy for liver tumors of all dignities. BACKGROUND: Outcomes after open major hepatectomies vary widely lacking reference values for comparisons among centers, indications, types of resections, and minimally invasive procedures. METHODS: A standard benchmark methodology was used covering consecutive patients, who underwent open major anatomic hepatectomy from 44 high-volume liver centers from 5 continents over a 5-year period (2016-2020). Benchmark cases were low-risk non-cirrhotic patients without significant comorbidities treated in high-volume centers (≥30 major liver resections/year). Benchmark values were set at the 75th percentile of median values of all centers. Minimum follow-up period was 1 year in each patient. RESULTS: Of 8044 patients, 2908 (36%) qualified as benchmark (low-risk) cases. Benchmark cutoffs for all indications include R0 resection ≥78%; liver failure (grade B/C) ≤10%; bile leak (grade B/C) ≤18%; complications ≥grade 3 and CCI ® ≤46% and ≤9 at 3 months, respectively. Benchmark values differed significantly between malignant and benign conditions so that reference values must be adjusted accordingly. Extended right hepatectomy (H1, 4-8 or H4-8) disclosed a higher cutoff for liver failure, while extended left (H1-5,8 or H2-5,8) were associated with higher cutoffs for bile leaks, but had superior oncologic outcomes, when compared to formal left hepatectomy (H1-4 or H2-4). The minimal follow-up for a conclusive outcome evaluation following open anatomic major resection must be 3 months. CONCLUSION: These new benchmark cutoffs for open major hepatectomy provide a powerful tool to convincingly evaluate other approaches including parenchymal-sparing procedures, laparoscopic/robotic approaches, and alternative treatments, such as ablation therapy, irradiation, or novel chemotherapy regimens.

PMCA inhibition reverses drug resistance in clinically refractory cancer patient-derived models.

BACKGROUND: Cancer cells have developed molecular strategies to cope with evolutionary stressors in the dynamic tumor microenvironment. Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) is a metabolic rheostat that regulates diverse cellular adaptive behaviors, including growth and survival. However, the mechanistic role of PGC1α in regulating cancer cell viability under metabolic and genotoxic stress remains elusive. METHODS: We investigated the PGC1α-mediated survival mechanisms in metabolic stress (i.e., glucose deprivation-induced metabolic stress condition)-resistant cancer cells. We established glucose deprivation-induced metabolic stress-resistant cells (selected cells) from parental tumor cells and silenced or overexpressed PGC1α in selected and parental tumor cells. RESULTS: Several in vitro and in vivo mouse experiments were conducted to elucidate the contribution of PGC1α to cell viability in metabolic stress conditions. Interestingly, in the mouse xenograft model of patient-derived drug-resistant cancer cells, each group treated with an anti-cancer drug alone showed no drastic effects, whereas a group that was co-administered an anti-cancer drug and a specific PMCA inhibitor (caloxin or candidate 13) showed marked tumor shrinkage. CONCLUSIONS: Our results suggest that PGC1α is a key regulator of anti-apoptosis in metabolic and genotoxic stress-resistant cells, inducing PMCA expression and allowing survival in glucose-deprived conditions. We have discovered a novel therapeutic target candidate that could be employed for the treatment of patients with refractory cancers.

The care cascade for hepatitis C virus and prognosis of chronic hepatitis C patients treated with antiviral agents in a tertiary hospital.

BACKGROUND: Some studies have analyzed the frequency of HCV RNA testing and actual treatment among anti-HCV positive patients in Korea, which has a low prevalence of HCV infection. This study aimed to analyze the diagnosis process, treatment results, and prognosis according to care cascade in patients who are anti-HCV positive. METHODS: Three thousand two hundred fifty-three anti-HCV positive patients presented to a tertiary hospital between January 2005 and December 2020. The number of patients who underwent HCV RNA testing, treatment, and proportion of sustained virologic response (SVR) according to the type of antivirals was investigated. We investigated the cumulative incidence of hepatocellular carcinoma (HCC) and liver cirrhosis. RESULTS: Of a total of 3,253 people, 1,177 (36.2%) underwent HCV RNA testing and 858 (72.9%) were positive for HCV RNA. 494 (57.6%) of HCV RNA positive patients received antiviral treatment, and 443 (89.7%) of initiated hepatitis C treatment experienced SVR. Of the 421 treated patients, 16 (14.2%) developed HCC. The cumulative incidence of HCC at 15 years was significantly different according to the presence of liver cirrhosis (10/83, 29.5% vs. 6/338, 10.8%, p < 0.001). The cumulative incidences of HCC or liver cirrhosis did not show significant differences according to the presence of SVR12 (14/388, 13.2% vs. 2/33, 52.5%, p = 0.084, 21/319, 15.0%, vs. 3/22, 28.7%, p = 0.051). CONCLUSIONS: Owing to the introduction of direct-acting antivirals, high SVR12 was achieved, but the proportion of anti-HCV positive patients who received HCV RNA testing and treatment was not high. HCC surveillance after SVR12 is recommended for chronic hepatitis C patients with cirrhosis.

ROS-induced PADI2 downregulation accelerates cellular senescence via the stimulation of SASP production and NFκB activation.

Cellular senescence is closely related to tissue aging including bone. Bone homeostasis is maintained by the tight balance between bone-forming osteoblasts and bone-resorbing osteoclasts, but it undergoes deregulation with age, causing age-associated osteoporosis, a main cause of which is osteoblast dysfunction. Oxidative stress caused by the accumulation of reactive oxygen species (ROS) in bone tissues with aging can accelerate osteoblast senescence and dysfunction. However, the regulatory mechanism that controls the ROS-induced senescence of osteoblasts is poorly understood. Here, we identified Peptidyl arginine deiminase 2 (PADI2), a post-translational modifying enzyme, as a regulator of ROS-accelerated senescence of osteoblasts via RNA-sequencing and further functional validations. PADI2 downregulation by treatment with H2O2 or its siRNA promoted cellular senescence and suppressed osteoblast differentiation. CCL2, 5, and 7 known as the elements of the senescence-associated secretory phenotype (SASP) which is a secretome including proinflammatory cytokines and chemokines emitted by senescent cells and a representative feature of senescence, were upregulated by H2O2 treatment or Padi2 knockdown. Furthermore, blocking these SASP factors with neutralizing antibodies or siRNAs alleviated the senescence and dysfunction of osteoblasts induced by H2O2 treatment or Padi2 knockdown. The elevated production of these SASP factors was mediated by the activation of NFκB signaling pathway. The inhibition of NFκB using the pharmacological inhibitor or siRNA effectively relieved H2O2 treatment- or Padi2 knockdown-induced senescence and osteoblast dysfunction. Together, our study for the first time uncover the role of PADI2 in ROS-accelerated cellular senescence of osteoblasts and provide new mechanistic and therapeutic insights into excessive ROS-promoted cellular senescence and aging-related bone diseases.

A Report on a Nationwide Surveillance System for Pediatric Acute Hepatitis of Unknown Etiology in Korea.

BACKGROUND: Several cases of pediatric acute hepatitis of unknown etiology related to adenoviral infections have been reported in Europe since January 2022. The aim of this study was to compare the incidence, severity, possible etiology, and prognosis of the disease with those in the past in Korea. METHODS: The surveillance group collected data between May and November 2022 using a surveillance system. Acute hepatitis of unknown etiology was defined in patients aged < 16 years with a serum transaminase level > 500 IU/L, not due to hepatitis A-E or other underlying causes. For comparison, data from 18 university hospitals were retrospectively collected as a control group between January 2021 and April 2022. RESULTS: We enrolled 270 patients (mean age, 5 years). The most common symptom was fever. However, the incidence was similar between 2021 and 2022. Liver function test results, number of patients with acute liver failure (ALF), liver transplantation (LT), death, and adenovirus detection rates did not differ between the two groups. None of the adenovirus-positive patients in either group experienced ALF, LT, or death. In the surveillance group, adenovirus-associated virus-2 was detected in four patients, one of whom underwent LT. Patients with an unknown etiology showed significantly higher bilirubin levels, a lower platelet count, and a higher LT rate than patients with a possible etiology. CONCLUSION: The incidence of pediatric acute hepatitis of unknown etiology and adenovirus detection rate have not increased in Korea.

Comparison of clinical and preimplantation genetic testing for aneuploidy outcomes between in vitro fertilization and intracytoplasmic sperm injection in sibling mature oocytes from high-risk patients: A retrospective study.

AIM: To evaluate the influence of insemination methods on clinical outcomes by assessing preimplantation genetic testing for aneuploidy (PGT-A) outcomes in embryos obtained using in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in sibling mature oocytes from high-risk patients. METHODS: This retrospective study involved 108 couples with nonmale or mild male factor infertility who underwent split insemination cycles from January 2018 to December 2021. PGT-A was performed using trophectoderm biopsy, array comparative genome hybridization, or next-generation sequencing with 24-chromosome screening. RESULTS: Mature oocytes were divided into IVF (n = 660) and ICSI (n = 1028) groups. The normal fertilization incidence was similar between the groups (81.1% vs. 84.6%). The total number of blastocysts biopsied was significantly higher in the IVF group than in the ICSI group (59.3% vs. 52.6%; p = 0.018). However, euploidy (34.4% vs. 31.9%) and aneuploidy (63.4% vs. 66.2%) rates per biopsy and clinical pregnancy rates (60.0% vs. 58.8%) were similar between the groups. Implantation (45.6% vs. 50.8%) and live birth or ongoing pregnancy (52.0% vs 58.8%) rates were slightly higher in the ICSI group than in the IVF group and miscarriage rate per transfer was slightly higher in the IVF group than in the ICSI group (12.0% vs 5.9%); however no significant difference was observed. CONCLUSIONS: IVF and ICSI using sibling mature oocytes had similar clinical outcomes, and euploidy and aneuploidy rates in couples with nonmale and mild male factor infertility. These results suggest that IVF is a useful option, along with ICSI, as an insemination method in PGT-A cycles, especially in high-risk patients.

Collapse after Carpal Bone Tunneling. An Underreported Complication?

PURPOSE: To report the complication of carpal bone tunnel collapse in scapholunate reconstruction. METHODS: The authors present six cases of carpal collapse or bone necrosis after bone tunneling for ligamentous reconstruction, three in the scaphoid bone and three in the lunate. RESULTS: All six cases were secondary to ligament reconstruction for chronic scapholunate dissociations, none of which had preoperative structural scaphoid or lunate deformities. CONCLUSIONS: Although the incidence of this occurrence is unknown, the consequences could be substantial; therefore, patients should be warned of this possibility when discussing complications of ligament reconstruction for chronic scapholunate instability requiring the creation of a bone tunnel. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Resource-Efficient Parallelized Random Access for Reliable Connection Establishment in Cellular IoT Networks.

The role of various internet-of-things (IoT) devices responsible for data collection and reporting becomes more important in the era of Industry 4.0. Due to the various advantages (e.g., wide coverage, robust security, etc.), the cellular networks have been continuously evolved to accommodate IoT scenario. In IoT scenario, connection establishment is essential and primary for enabling IoT devices to communicate with centralized unit (e.g., base station (BS)). This connection establishment procedure in cellular networks, random access procedure, is generally operated in a contention-based manner. So, it is vulnerable to simultaneous connection requests from multiple IoT devices to the BS, which becomes worse as the contention participants increase. In this article, we newly propose a resource-efficient parallelized random access (RePRA) procedure for resource-efficiently ensuring reliable connection establishment in cellular-based massive IoT networks. Key features of our proposed technique are twofold: (1) Each IoT device simultaneously performs multiple RA procedures in parallel to improve connection establishment success probability, and (2) the BS handles excessive use of radio resources based on newly proposed two types of redundancy elimination mechanisms. Through extensive simulations, we evaluate the performance of our proposed technique in terms of connection establishment success probability and resource efficiency under various combinations of control parameters. Consequently, we verify the feasibility of our proposed technique for reliably and radio-efficiently supporting a large number of IoT devices.

IVM of human immature oocytes for infertility treatment and fertility preservation.

Background: Thousands of healthy babies are born from in vitro maturation (IVM) procedures, but the rate of efficiency differs with the source of immature oocytes obtained. Recently, there are different IVM protocols proposed for infertility treatment and fertility preservation. Methods: Based on the literature, the clinical application for IVM of immature oocytes was summarized. Main findings Results: Immature oocytes may be retrieved from women after priming with or without the use of follicular stimulation hormone (FSH), human chorionic gonadotrophin (hCG) or a combination of both FSH and hCG. Successful pregnancy rates with IVM technology seem to be correlated with the number of immature oocytes obtained. With the source and culture course of immature oocytes, there are various IVM protocols. IVM of immature oocytes is profoundly affected by the culture conditions, but no breakthrough has been made by improving the IVM medium itself. Thus, the clinical application of IVM technology continues to evolve. Conclusion: IVM technology is a useful technique for infertile women and fertility preservation. Mild stimulation IVF combined with IVM of immature oocytes is a viable alternative to the conventional stimulation IVF cycle treatment as it may prove to be an optimal first-line treatment approach.

Dynamical Study of Adsorbate-Induced Restructuring Kinetics in Bimetallic Catalysts Using the PdAu(111) Model System.

Dynamic restructuring of bimetallic catalysts plays a crucial role in their catalytic activity and selectivity. In particular, catalyst pretreatment with species such as carbon monoxide and oxygen has been shown to be an effective strategy for tuning the surface composition and morphology. Mechanistic and kinetic understanding of such restructuring is fundamental to the chemistry and engineering of surface active sites but has remained challenging due to the large structural, chemical, and temporal degrees of freedom. Here, we combine time-resolved temperature-programmed infrared reflection absorption spectroscopy, ab initio thermodynamics, and machine-learning molecular dynamics to uncover previously unidentified timescale and kinetic parameters of in situ restructuring in Pd/Au(111), a highly relevant model system for dilute Pd-in-Au nanoparticle catalysts. The key innovation lies in utilizing CO not only as a chemically sensitive probe of surface Pd but also as an agent that induces restructuring of the surface. Upon annealing in vacuum, as-deposited Pd islands became encapsulated by Au and partially dissolved into the subsurface, leaving behind isolated Pd monomers on the surface. Subsequent exposure to 0.1 mbar CO enabled Pd monomers to repopulate the surface up to 373 K, above which complete Pd dissolution occurred by 473 K, with apparent activation energies of 0.14 and 0.48 eV, respectively. These restructuring processes occurred over the span of ∼1000 s at a given temperature. Such a minute-timescale dynamics not only elucidates the fluxional nature of alloy catalysts but also presents an opportunity to fine-tune the surface under moderate temperature and pressure conditions.

RANKL down-regulates the mast cell proliferation through inducing senescence.

An increase in the number of mast cells could contribute to inflammatory diseases and pathologic conditions. A receptor activator of NF-κB ligand (RANKL)/RANK system is one of the key signaling pathways accelerating mast cell-mediated allergic inflammatory reactions. However, the biological functions of RANKL in mast cell proliferation remains to be clarified. The aim of the present study is to clarify the role of RANKL in mast cell proliferation. Surprisingly, RANKL remarkably reduced the proliferation of human mast cell line, HMC-1 cells through the inhibition of murine double minute 2 (MDM2) and Ki-67 mRNA expressions in a dose-dependent manner. RANKL significantly reduced cell viability, whereas it increased cellular senescence via increasing levels of p53, phosphorylated(p)-p53, p21, and p16 and decreasing levels of retinoblastoma protein (pRb) and p-pRb in HMC-1 cells. Even in rat peritoneal mast cells, RANKL induced cellular senescence by increasing filamentous-actin polymerization. In addition, RANKL remarkably reduced thymic stromal lymphopoietin (TSLP)-induced mast cell proliferation via the downregulation of MDM2 and Ki-67. RANKL decreased levels of p-signal transducer and activator of transcription 6 in TSLP-stimulated HMC-1 cells. The mast cell growth factor, interleukin-13 was remarkably down-regulated by treatment with RANKL in TSLP-stimulated HMC-1 cells. Furthermore, RANKL increased the number of senescence-associated ß-galactosidase-stained cells and protein levels of p53, p-p53, and p21 in TSLP-stimulated HMC-1 cells. These data suggest that RANKL down-regulates mast cell proliferation by inducing senescence.

Squaraine probes for the bimodal staining of lipid droplets and endoplasmic reticulum imaging in live cells.

Lipid droplets (LDs) have emerged as a hot target for cancer therapeutics in recent years owing to findings that have shown them to be key organelles involved in maintaining cellular stability and regulating inter-organelle communication through molecular trafficking. LDs emerge from the endoplasmic reticulum (ER) as a form of cellular homeostasis control. We herein report the study of a library of asymmetric squaraines as superior fluorescence probes to track and image LDs in their native state and environment within cancer cells. The probes are highly selective towards LDs and displayed prominent bright fluorescence with just 1 µM probe concentration. They also possess bimodal LD and ER staining capability via the simple diffusion of small lipophilic molecules. The probes almost instantly stained LDs, while the ER staining rate is dependent on the probe's lipophilicity and the incubation duration. These "on-demand" organelle-selective probes are highly desirable tools for revealing the role of LDs in governing many cellular processes, especially in malignant cells.

Guidelines to Achieving High Selectivity for the Hydrogenation of α,ß-Unsaturated Aldehydes with Bimetallic and Dilute Alloy Catalysts: A Review.

Selective hydrogenation of α,ß-unsaturated aldehydes to unsaturated alcohols is a challenging class of reactions, yielding valuable intermediates for the production of pharmaceuticals, perfumes, and flavorings. On monometallic heterogeneous catalysts, the formation of the unsaturated alcohols is thermodynamically disfavored over the saturated aldehydes. Hence, new catalysts are required to achieve the desired selectivity. Herein, the literature of three major research areas in catalysis is integrated as a step toward establishing the guidelines for enhancing the selectivity: reactor studies of complex catalyst materials at operating temperature and pressure, surface science studies of crystalline surfaces in ultrahigh vacuum, and first-principles modeling using density functional theory calculations. Aggregate analysis shows that bimetallic and dilute alloy catalysts significantly enhance the selectivity to the unsaturated alcohols compared to monometallic catalysts. This comprehensive review focuses primarily on the role of different metal surfaces as well as the factors that promote the adsorption of the unsaturated aldehyde via its C═O bond, most notably by electronic modification of the surface and formation of the electrophilic sites. Furthermore, challenges, gaps, and opportunities are identified to advance the rational design of efficient catalysts for this class of reactions, including the need for systematic studies of catalytic processes, theoretical modeling of complex materials, and model studies under ambient pressure and temperature.