Catalyst-free selective oxidation of C(sp3)-H bonds in toluene on water.

The anisotropic water interfaces provide an environment to drive various chemical reactions not seen in bulk solutions. However, catalytic reactions by the aqueous interfaces are still in their infancy, with the emphasis being on the reaction rate acceleration on water. Here, we report that the oil-water interface activates and oxidizes C(sp3)-H bonds in toluene, yielding benzaldehyde with high selectivity (>99%) and conversion (>99%) under mild, catalyst-free conditions. Collision at the interface between oil-dissolved toluene and hydroxyl radicals spontaneously generated near the water-side interfaces is responsible for the unexpectedly high selectivity. Protrusion of free OH groups from interfacial water destabilizes the transition state of the OH-addition by forming π-hydrogen bonds with toluene, while the H-abstraction remains unchanged to effectively activate C(sp3)-H bonds. Moreover, the exposed free OH groups form hydrogen bonds with the produced benzaldehyde, suppressing it from being overoxidized. Our investigation shows that the oil-water interface has considerable promise for chemoselective redox reactions on water without any catalysts.

Metallosupramolecular Multiblock Copolymers of Lanthanide Complexes by Seeded Living Polymerization.

Supramolecular block copolymers, derived via seeded living polymerization, are increasingly recognized for their rich structural and functional diversity, marking them as cutting-edge materials. The use of metal complexes in supramolecular block copolymerization not only offers a broad range of block copolymers through the structural similarity in the coordination geometry of the central metal ion but also controls spectroscopic properties, such as emission wavelength, emission strength, and fluorescence lifetime. However, the exploration of metallosupramolecular multiblock copolymerization based on metal complexes remains quite limited. In this work, we present a pioneering synthesis of metallosupramolecular multiblock copolymers utilizing Eu3+ and Tb3+ complexes as building blocks. This is achieved through the strategic manipulation of nonequilibrium self-assemblies via a living supramolecular polymerization approach. Our comprehensive exploration of both thermodynamically and kinetically regulated metallosupramolecular polymerizations, centered around Eu3+ and Tb3+ complexes with bisterpyridine-modified ligands containing R-alanine units and a long alkyl group, has highlighted intriguing behaviors. The monomeric [R-L1Eu(NO3)3] complex generates a spherical structure as the kinetic product. In contrast, the monomeric [R-L1Eu2(NO3)6] complex generates fiber aggregates as a thermodynamic product through intermolecular interactions such as π-π stacking, hydrophobic interaction, and H-bonds. Utilizing the Eu3+ complex, we successfully conducted seed-induced living polymerization of the monomeric building unit under kinetically regulated conditions. This yielded a metallosupramolecular polymer of precisely controlled length with minimal polydispersity. Moreover, by copolymerizing the kinetically confined Tb3+ complex state ("A" species) with a seed derived from the Eu3+ complex ("B" species), we were able to fabricate metallosupramolecular tri- and pentablock copolymers with A-B-A, and B-A-B-A-B types, respectively, through a seed-end chain-growth mechanism.

Intra-Lysosomal Peptide Assembly for the High Selectivity Index against Cancer.

Lysosomes remain powerful organelles and important targets for cancer therapy because cancer cell proliferation is greatly dependent on effective lysosomal function. Recent studies have shown that lysosomal membrane permeabilization induces cell death and is an effective way to treat cancer by bypassing the classical caspase-dependent apoptotic pathway. However, most lysosome-targeted anticancer drugs have very low selectivity for cancer cells. Here, we show intra-lysosomal self-assembly of a peptide amphiphile as a powerful technique to overcome this problem. We designed a peptide amphiphile that localizes in the cancer lysosome and undergoes cathepsin B enzyme-instructed supramolecular assembly. This localized assembly induces lysosomal swelling, membrane permeabilization, and damage to the lysosome, which eventually causes caspase-independent apoptotic death of cancer cells without conventional chemotherapeutic drugs. It has specific anticancer effects and is effective against drug-resistant cancers. Moreover, this peptide amphiphile exhibits high tumor targeting when attached to a tumor-targeting ligand and causes significant inhibition of tumor growth both in cancer and drug-resistant cancer xenograft models.

Direct measurements of the colloidal Debye force.

Colloids often behave in a manner similar to their counterparts in molecular space and are used as model systems to understand molecular behavior. Here, we study like-charged colloidal attractions between a permanent dipole on an interfacial particle and its induced dipole on a water-immersed particle caused by diffuse layer polarization. We find that the scaling behavior of the measured dipole-induced dipole (D‒I) interaction via optical laser tweezers is in good agreement with that predicted from the molecular Debye interaction. The dipole character propagates to form aggregate chains. Using coarse-grained molecular dynamic simulations, we identify the separate roles of the D‒I attraction and the van der Waals attraction on aggregate formation. The D‒I attraction should be universal in a broad range of soft matter, such as colloids, polymers, clays, and biological materials, motivating researchers to further conduct in-depth research on these materials.

Circularly Polarized Luminescence Active Supramolecular Nanotubes Based on PtII Complexes That Undergo Dynamic Morphological Transformation and Helicity Inversion.

Circularly polarized luminescence (CPL) with tunable chirality is currently a challenging issue in the development of supramolecular nanomaterials. We herein report the formation of helical nanoribbons which grow into helical tubes through dynamic helicity inversion. For this, chiral PtII complexes of terpyridine derivatives, namely S-trans-1 and R-trans-1, with respective S- and R-alanine subunits and incorporating trans-double bonds in the alkyl chain were prepared. In DMSO/H2 O (5 : 1 v/v), S-trans-1 initially forms a fibrous self-assembled product, which then undergoes dynamic transformation into helical tubes (left-handed or M-type) through helical ribbons (right-handed or P-type). Interestingly, both helical supramolecular architectures are capable of emitting CPL signals. The metastable helical ribbons show CPL signals (glum =±4.7×10-2 ) at 570 nm. Meanwhile, the nanotubes, which are the thermodynamic products, show intense CPL signals (glum =±5.6×10-2 ) at 610 nm accompanied by helicity inversion. This study provides an efficient way to develop highly dissymmetric CPL nanomaterials by regulating the morphology of metallosupramolecular architectures.

Synchronously Multiple Gastric Adenocarcinomas with Intestinal Mucin Phenotype in a Patient not Infected with Helicobacter pylori, Showing a Gastritis-like Appearance.

Helicobacter pylori (H. pylori)-negative gastric cancer (HPNGC) usually shows a gastric mucin phenotype, but there are a few case reports of HPNGC with an intestinal mucin phenotype. We herein report a case of multiple HPNGC with an intestinal mucin phenotype showing a gastritis-like appearance. A 68-year-old H. pylori-uninfected man was suspected of having antral gastritis on endoscopy, but a histologic examination revealed multiple well-differentiated adenocarcinomas with positive-CDX2/MUC2/CD10 and negative-MUC5AC/MUC6. P53 was overexpressed, and intestinal metaplasia was sporadically detected in the non-atrophic mucosal background, thus indicating H. pylori-unrelated multistage carcinogenesis. The neoplastic surfaces were covered by a non-neoplastic epithelium, which caused a gastritis-like appearance. This report suggested the possibility of overlooking this neoplasm.

Thyroid Stimulating Hormone Reference Range and Prevalence of Thyroid Dysfunction in the Korean Population: Korea National Health and Nutrition Examination Survey 2013 to 2015.

BACKGROUND: No nationwide epidemiological study evaluating the prevalence of subclinical and overt forms of hypothyroidism and hyperthyroidism has yet been conducted in Korea. This study aimed to evaluate the reference range of serum thyroid stimulating hormone (TSH) and the national prevalence of thyroid dysfunctions in Korea. METHODS: Nation-wide cross-sectional data were analyzed from a representative sample of the civilian, non-institutionalized Korean population (n=6,564) who underwent blood testing for thyroid function and anti-thyroid peroxidase antibody (TPOAb) as part of the Korea National Health and Nutrition Examination Survey VI (2013 to 2015). RESULTS: The reference interval of serum TSH in the Korean reference population was 0.62 to 6.68 mIU/L. Based on this reference interval, the prevalence of overt and subclinical hypothyroidism was 0.73% (males 0.40%, females 1.10%) and 3.10% (males 2.26%, females 4.04%), respectively. The prevalence of hypothyroidism increased with age until the age group between 50 to 59 years. Positive TPOAb were found in 7.30% of subjects (males 4.33%, females 10.62%). The prevalence of overt and subclinical hypothyroidism TPOAb-positive subjects was 5.16% and 10.88%, respectively. The prevalence of overt and subclinical hyperthyroidism was 0.54% (males 0.30%, females 0.81%) and 2.98% (males 2.43%, females, 3.59%), respectively. CONCLUSION: The Serum TSH reference levels in the Korean population were higher than the corresponding levels in Western countries. Differences were found in the prevalence of hypothyroidism and hyperthyroidism according to age, sex, and TPOAb positivity. This study provides important baseline information for understanding patterns of thyroid dysfunction and diseases in Korea.

Effect of proprioceptive training on foot posture, lower limb alignment, and knee adduction moment in patients with degenerative knee osteoarthritis: a randomized controlled trial.

[Purpose] The purpose of this study was to determine the effect of proprioceptive training on foot progression angle, weight-bearing ratio, and knee adduction moment in patients with degenerative osteoarthritis of the knee. [Subjects] The subjects were 37 patients diagnosed with Kellgren-Lawrence grade 2 or 3 degenerative knee osteoarthritis. They were randomly allocated to three groups: a proprioceptive training group (PT group), quadriceps strengthening group (QS group), and control group. [Methods] The study parameters of the three groups were compared before and after a 12-week training period. Therapeutic exercises were performed twice per week for 12 weeks. Outcomes included the foot progression angle, weight-bearing ratio, and knee adduction moment. [Results] First, a significant difference in the foot progression angle was observed among the groups, significantly increasing in the PTG compared with the CG. Second, a significant difference in the weight-bearing ratio was observed among the groups, significantly increasing in the PTG compared with the CG. Third, a significant difference in the first peak knee adduction moment was observed among the groups, significantly decreasing in the PTG compared with the CG. [Conclusion] The results of the present study indicate that proprioceptive training increased the foot progression angle and weight-bearing ratio and decreased the first peak knee adduction moment. Moreover, incorporating proprioceptive training into a physical therapy exercise program could improve functional ability and delay the progression of degenerative osteoarthritis.

Relationships among foot position, lower limb alignment, and knee adduction moment in patients with degenerative knee osteoarthritis.

[Purpose] The aim of this study was to determine the relationships among the foot progression angle, foot rotation angle, lower limb alignment, and knee adduction moments in patients with degenerative knee osteoarthritis (OA). [Subjects] Forty-eight patients diagnosed with degenerative knee OA (Kellgren-Lawrence grades 2 and 3) were included. [Methods] To assess the lower extremity alignment and weight-bearing ratio, static radiographic measurement was used. Foot progression angle, foot rotation angle, and knee adduction moments were measured by using a three-dimensional motion analysis system. [Results] The results of this study were as follows: the foot progression angle in the early and late stance phase was significantly correlated with the first and second peak knee adduction moments; the weight-bearing ratio was significantly correlated with the first and second peak knee adduction moments; and the tibiofemoral angle was significantly correlated with the first and second peak knee adduction moments. [Conclusion] The results of the present study indicated that as the foot progression angle and the foot lateral rotation angle increased, the knee adduction moment decreased. The weight-bearing ratio and tibiofemoral angle assessment with mechanical axis alignment were correlated with the knee adduction moments. These parameters may be helpful for selecting therapeutic options for patients with degenerative knee OA.

Changes in seroprevalence of hepatitis B surface antigen and epidemiologic characteristics in the Republic of Korea, 1998-2013.

OBJECTIVES: This study investigated changes in hepatitis B seroprevalence from 1998 to 2013, and to identify differences in epidemiologic characteristics between hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative people. METHODS: HBsAg seropositive rates were compared by year, sex, and age using the blood test data from the periods I to VI (1998-2013) of the Korea National Health and Nutrition Examination Survey. Interviews and self-administered surveys were conducted to collect data on health behavior, quality of life, comorbidities, and health care utilization. RESULTS: HBsAg seropositive rates in the Republic of Korea decreased from 4.6% in 1998 to 2.9% in 2008, and then remained the same for the next five years. While seropositive rates by age were the highest at 35 to 39 years of age in 1998, it peaked at 50 to 54 years of age in 2013. HBsAg-positive people showed high values from two liver function tests, including glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase, and the prevalence rates of liver cirrhosis and liver cancer were also significantly high. Indices for health behavior and quality of life showed no significant differences between HBsAg-positive and HBsAg-negative people. CONCLUSIONS: While HBsAg seropositive rates tended to decline after 1998, there have been no significant changes over the most recent five years. We should focus on treatment of existing hepatitis B patients along with immunization programmes to prevent new hepatitis B infections. In addition, it may be necessary to encourage HBsAg-positive people to follow healthier life-styles in order to prevent further progression of hepatitis B to liver cirrhosis and liver cancer.

Trends in the prevalence of major cardiovascular disease risk factors among Korean adults: results from the Korea National Health and Nutrition Examination Survey, 1998-2012.

BACKGROUND: Mortality from coronary heart disease in Korea has increased continuously, but there are few comprehensive national data on trend in the prevalence of risk factors for cardiovascular disease in this population. We examined the trends in the prevalence of major risk factors for cardiovascular disease, including smoking, obesity, hypertension, diabetes, and hypercholesterolemia, from 1998 through 2012 in a representative Korean population. METHODS: Using data from the Korea National Health and Nutrition Examination Survey I (1998) to V (2010-2012), we selected the adults aged≥30 yr who participated in both a health examination and health interview survey. RESULTS: From 1998 to 2012, significant decrease in the prevalence of hypertension was observed in both men (32.5 to 31.5%) and women (26.9 to 24.3%). Smoking rates decreased only in men (65.1 to 47.0%), whereas the prevalence of diabetes did not change over time. Conversely, the prevalence of hypercholesterolemia significantly increased from 7.2% to 12.6% for men and from 8.4% to 14.9% for women, whereas the rates of awareness and treatment for hypercholesterolemia were relatively lower than that of hypertension and diabetes. During the period, prevalence of obesity significantly increased from 26.8% to 38.1% only in men. CONCLUSIONS: The increased prevalence of hypercholesterolemia and obesity may have contributed to the increasing trend in the mortality from coronary heart disease in Korea. Further population-based surveillance of blood cholesterol levels and obesity needs to be performed, and national strategies for improvement of these factors should be established in Korea.

Inhibitory effect of panduratin A isolated from Kaempferia panduarata Roxb. on melanin biosynthesis.

Hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, thus melanin synthesis inhibitors have been of great interest as target molecules for cosmetic and medicinal purposes. The aim of this study was to investigate the in vitro inhibitory effect of panduratin A, isolated from Kaempferia pandurata Roxb., on melanogenesis and its related enzymes such as tyrosinase, tyrosinase related protein-1 (TRP-1) and tyrosinase related protein-2 (TRP-2) in melan-a murine melanocytes. The IC(50) values of panduratin A for melanogenesis and tyrosinase were 9.6 µm and 8.2 µm, respectively, while those of arbutin as a positive control were 990 µm and 660 µm, respectively. In western blot analysis, panduratin A also significantly decreased tyrosinase, TRP-1 and TRP-2 protein levels. These results indicate that panduratin A effectively inhibits melanin biosynthesis, thus creating the possibility of developing a new skin-whitening agent.

Inhibitory effects of macelignan isolated from Myristica fragrans HOUTT. on melanin biosynthesis.

The aim of this study was to investigate the in vitro inhibitory effects of macelignan isolated from Myristica fragrans HOUTT. on melanogenesis and its related enzymes such as tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2) in melan-a murine melanocytes. The IC50 values of macelignan for melanogenesis and tyrosinase were 13 microM and 30 microM, respectively, while those of arbutin as a positive control were 990 microM and 660 microM, respectively. In Western blot analysis, macelignan also significantly decreased tyrosinase, TRP-1, and TRP-2 protein expression. These results indicate that macelignan effectively inhibits melanin biosynthesis and thus could be employed as a new skin-whitening agent.

Depigmentation of melanocytes by isopanduratin A and 4-hydroxypanduratin A isolated from Kaempferia pandurata ROXB.

This study was carried out to investigate the in vitro effects of isopanduratin A and 4-hydroxypanduratin A isolated from Kaempferia pandurata ROXB. on melanin biosynthesis and tyrosinase activity. Two chalcone compounds, isopanduratin A and 4-hydroxypanduratin A, were isolated from the ethyl acetate fraction of ethanol extract as the active principles. Compared with phenylthiourea (IC(50)=34.3 microM) as a positive control, the depigmentation IC(50) values for isopanduratin A and 4-hydroxypanduratin A were 10.6 microM and 23.2 microM, respectively. The compounds also significantly inhibited the activity of tyrosinase, the enzyme that converts DOPA (3,4-dihydroxyphenylalanine) to dopachrome in the biosynthetic process of melanin. The IC(50) values of isopanduratin A and 4-hydroxypanduratin A for tyrosinase were 10.5 microM and >30 microM, respectively, while that of phenylthiourea was 47.6 microM. The tyrosinase protein level was also significantly decreased by isopanduratin A and 4-hydroxypanduratin A. The results indicate that isopanduratin A and 4-hydroxypanduratin A isolated from K. pandurata ROXB. are promising compounds that could be useful for treating hyperpigmentation as skin-whitening agents.