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Untreated and sulfonated biomass-derived amorphous carbons were prepared by the pyrolysis of D-glucose at different temperatures, followed by sulfonation. Not only the surface functional group concentration but also the structure of polyaromatic carbon sheets was significantly affected by the carbonization temperature and sulfonation. More importantly, the carbonization temperature played a crucial role in determining the size of Pd nanoparticles (NPs) on glucose-derived carbons (GCx) and thereby affected the catalytic performance of Pd/GCx for the direct synthesis of hydrogen peroxide (DSHP). The volcano-shaped dependency between the Pd NP size and the carbonization temperature of GCx agrees well with the reverse relationship between the Pd NP size and the catalytic activity of Pd/GCx. The flexible polyaromatic carbon sheet structure of the GCx was beneficial in increasing the sulfonic acid group content on the carbon surface and, therefore, H2O2 selectivity was improved in the presence of the Pd/S-GC2 catalyst (Pd supported on the sulfonated glucose-derived carbon pyrolyzed at 723 K). However, both H2 conversion and H2O2 productivity decreased over the same catalyst, possibly due to the decreased number of active sites on the clustered or single-site Pd. Reducing the catalyst resulted in a decrease in H2O2 selectivity by significantly lowering the Pd2+/Pd0 ratio and increasing the Pd NP size. These results clearly demonstrate that fine control of the physicochemical properties of the active metal and GCx support and their synergistic combination is essential to realize an efficient Pd catalyst supported on GCx for the DSHP reaction.

Boosting anticancer immunity by blocking immune checkpoints such as the programmed death-1 (PD-1) or its ligand (PD-L1) is a breakthrough anticancer therapy. However, many cancer patients do not respond well to immune checkpoint blockades (ICBs) alone. Here we show that low-dose pharmacological immunoactivators (e.g., SN38, topotecan, sorafenib, etc.) notably downregulate PD-L1 and upregulate FOXO3 expression in various human and murine cancer cell lines. In a mouse tumor model, low-dose SN38 treatment markedly suppresses tumor growth, reduces PD-L1 expression, and enhances FOXO3 expression in primary tumor specimens. SN38 therapy engages the tumor-infiltrating mouse NK1.1/CD49b/NKG2D-positive natural killer (NK) cells to attack tumor cells by inducing mouse IFN-γ and granzyme-B secretion in the tumor microenvironment (TME) in vivo. SN38 treatment also promotes tumor cell apoptosis in the TME. SN38 treatment significantly decreases STAT3-pY705 and IL-6 protein levels; FOXO3 is essential for SN38-mediated PD-L1 downregulation. Collectively, these findings may contribute to future translational or clinical investigations tackling difficult-to-treat cancers with immune-activating medicines or combined with ICB immunotherapy.

Although a wide range of Pd/C catalysts has been developed for the direct synthesis of H2O2, low H2O2 yields remain a challenging issue. In this study, we propose a novel catalyst design involving the formation of Pd@Co(BO3)2 core-shell nanoparticles (NPs) on an activated carbon support followed by the cobalt borate shell etching with H3PO4. The non-noble metal shell efficiently suppressed unfavorable aggregation of Pd NPs, resulting in the formation of small and monodisperse Pd NPs after stripping the cobalt. The use of H3PO4 was also beneficial to obtain a high H2O2 yield by decreasing the metallic nature of Pd and enabling the acid-treated activated carbon to act as a solid acid support. The features of the acid-treated Pd/C catalyst derived from the Pd@Co(BO3)2 core-shell were superior enough for achieving extremely high activity in the direct synthesis of H2O2. The H2O2 productivity of 5721 mmol-H2O2/g-Pd.h with 88.1% H2O2 selectivity reported herein is one of the best values among Pd/C catalysts developed to date. It was also demonstrated that the cobalt borate shell should be completely removed because cobalt accelerated H2O2 decomposition and hydrogenation.

Although various Pd/C catalysts have been applied in the direct synthesis of H2O2, unsatisfactory H2O2 yields have been achieved. We systematically investigated the effect of heat treatment on the physicochemical properties of Pd/C catalyst, and thereby on the catalytic performance in the direct synthesis of H2O2. Pd/C catalysts prepared by the incipient wetness method were subjected to different heat treatments and applied in H2O2 synthesis. The calcination temperature was found to have a key role in determining the Pd nanoparticle (NP) size; calcination at 523 K yielded highly oxidized and small Pd NPs corresponding to the sub-nano domain (1.4–2.5 nm). This Pd/C catalyst is superior not only in promoting H2O2 formation, but also in suppressing the subsequent unfavorable H2O2 decomposition and hydrogenation, which explains its excellent H2O2 productivity (as high as 4,443 mmol H2O2/g Pd·h) and selectivity (94.5%). On the other hand, the reaction performance of the Pd/C catalysts calcined at a higher temperature (673 K) or reduced under hydrogen was sharply reduced owing to the formation of larger Pd NPs or the enhancement of the metallic nature of Pd, respectively The amount of residual Cl ion on Pd/C catalyst after heat treatment also had an impact on the catalytic activity as it affected the pH of reaction solution. These results clearly demonstrate that an efficient Pd/C catalyst can be realized by fine tuning the conditions of heat treatment during catalyst preparation.

Direct synthesis of H2O2 from H2 and O2 can avoid the energy and environmental problems of current multi-step anthraquinone oxidation process by enabling high atom utilization and generating only a water by-product. However, the direct process suffers a low H2O2 yield, and it is challenging to suppress the unfavorable side-reactions in the absence of corrosive additives under the restriction of explosion limits. In this study, an efficient new catalyst was prepared by immobilizing Pd nanoparticles (NPs) on an acidic hyper-crosslinked porous polymer (HCPP). The Pd catalyst supported on HCPP functionalized with both carboxylic and sulfonic acids (Pd/c-s-HCPP) achieved as high as 3130 mmol H2O2/g Pd.h with 82% selectivity to H2O2, which corresponded to one of the best catalysts reported so far. Pd/c-s-HCPP showed superior catalytic performance when compared with ones by Pd NPs supported on unfunctionalized HCPP (Pd/HCPP), or sulfonated resin (Pd/SO3H-resin). Extensive characterizations and H2 adsorption measurements indicated that the c-s-HCPP provided (i) selective adsorption sites for Pd precursors, (ii) acted as an efficient H2 reservoir in the proximity of the small Pd NPs formed, and (iii) imparts solid acidity to enhance H2O2 selectivity, which offered a new direction in the catalyst design for the direct synthesis of H2O2.

BackgroundStimulating antitumor immunity by blocking programmed death-1 (PD-1) or its ligand (programmed death-ligand 1 (PD-L1) is a promising antitumor therapy. However, numerous patients respond poorly to PD-1/PD-L1 blockade. Unresponsiveness to immune-checkpoint blockade (ICB) can cast significant challenges to the therapeutic options for patients with hard-to-treat tumors. There is an unmet clinical need to establish new therapeutic approaches for mitigating ICB unresponsiveness in patients. In this study, we investigated the efficacy and role of low-dose antineoplastic agent SN-38 or metformin in sensitizing unresponsive tumors to respond to ICB therapy.MethodsWe assessed the significant pathological relationships between PD-L1 and FOXO3 expression and between PD-L1 and c-Myc or STAT3 expression in patients with various tumors. We determined the efficacy of low-dose SN-38 or metformin in sensitizing unresponsive tumors to respond to anti-PD-1 therapy in a syngeneic tumor system. We deciphered novel therapeutic mechanisms underlying the SN-38 and anti-PD-1 therapy-mediated engagement of natural killer (NK) or CD8+ T cells to infiltrate tumors and boost antitumor immunity.ResultsWe showed that PD-L1 protein level was inversely associated with FOXO3 protein level in patients with ovarian, breast, and hepatocellular tumors. Low-dose SN-38 or metformin abrogated PD-L1 protein expression, promoted FOXO3 protein level, and significantly increased the animal survival rate in syngeneic mouse tumor models. SN-38 or metformin sensitized unresponsive tumors responding to anti-PD-1 therapy by engaging NK or CD8+ T cells to infiltrate the tumor microenvironment (TME) and secret interferon-γ and granzyme B to kill tumors. SN-38 suppressed the levels of c-Myc and STAT3 proteins, which controlled PD-L1 expression. FOXO3 was essential for SN38-mediated PD-L1 suppression. The expression of PD-L1 was compellingly linked to that of c-Myc or STAT3 in patients with the indicated tumors.ConclusionWe show that SN-38 or metformin can boost antitumor immunity in the TME by inhibiting c-Myc and STAT3 through FOXO3 activation. These results may provide novel insight into ameliorating patient response to overarching immunotherapy for tumors.

A new catalyst preparation method involving the sequential ligand exchange of anionic palladium complexes to cationic complexes via the formation of palladium hydroxide intermediates is proposed. The novel method enables the electrostatic adsorption of an anionic palladium complex on the negatively charged carbon surface, and therefore makes it possible to obtain small and highly dispersed Pd nanoparticles. The H2O2 productivity and H2 selectivity of the ligand-exchanged catalyst were 16 and 3.6 times higher than those of the Pd/C catalyst prepared by using the same anionic palladium precursor. The strikingly different activities mainly attributed to the difference in the nanoparticle size and the oxidation state of Pd, which clearly indicates that the activity of Pd/C catalyst for the direct synthesis of H2O2 can be greatly improved by the sequential ligand exchange method.

A new catalyst design based on selective adsorption deposition method was developed to achieve high reaction performance in the direct synthesis of hydrogen peroxide. The activity of the unprecedented Pd/C catalyst was superior to that of the conventionally prepared Pd/C catalysts, and the initial H2O2 productivity and H2 selectivity reached as high as 8606 mmol H2O2/g Pd.h and 95.1%, respectively. This excellent activity may result from the intrinsic structural and electronic features of the active sites, i.e., the extremely small and monodispersed Pd nanoparticles with a high Pd2+/Pd0 ratio, which were realized by combining the selective adsorption of metal precursor cations on a negatively charged activated carbon surface and the subsequent homogeneous surface deposition of palladium hydroxide by the hydroxide ions that are slowly generated upon urea decomposition. The catalytic activity was significantly affected by the oxygen groups of the activated carbon support. The carboxyl groups do not efficiently suppress the unfavorable H-OOH dissociation but rather accelerate the H 2O2 hydrolysis by forming hydrogen bonds with H2O2. Moreover, a sharp decrease in the reaction rates of H2O2 hydrogenation and direct synthesis of H2O2 was observed with the increase in the number of carboxyl groups on the activated carbon surface. This loss of activity, as confirmed by acid treatment and olefin hydrogenation experiments, implies that the carboxyl groups in close proximity to the active sites have a detrimental effect by hindering or poisoning the active sites.

Pd nanoparticles with a mean diameter of 2.2 nm on amine-functionalized UiO-66 were synthesized by facile anionic-exchange followed by chemical reduction. The prepared Pd/NH2-UiO-66 catalyst was effective in the catalytic transfer hydrogenation of nitrobenzene to aniline using formic acid as a hydrogen source under mild reaction conditions in water with a maximum nitrobenzene conversion of 98% and an aniline selectivity of 99%. The superior catalytic activity of Pd/NH2-UiO-66 was attributed to the cooperative effects of nano-sized Pd and its stabilization offered by the NH2-UiO-66 support. The heterogeneous nature of the catalytic system was confirmed by a hot-filtering test and the catalyst maintained stable performance in 4 repeated cycles. A plausible reaction mechanism was proposed.

A Rh/ED-KIT-6 catalyst comprised of Rh nanoparticles embedded on mesoporous silica (KIT-6) functionalized with N1-[3-(trimethoxysilyl)propyl]ethane-1,2-diamine was synthesized by Rh3+ adsorption and chemical reduction in the liquid phase. The structure of ED-KIT-6 and textural properties of the pristine and supported Rh catalysts, as well as particle size and chemical state of the Rh species were examined by various analytical methods. The homogeneous dispersion of ultra-small Rh nanoparticles, ca.1.2 nm in size, stabilized by the grafted diamine species was confirmed. Rh/ED-KIT-6 was applied to the transfer hydrogenation of furfural (FFR) to furfuryl alcohol (FAL) using formic acid (FA) as the hydrogen source. The effect of the solvent and reaction parameters, such as temperature, reaction time, and FA/FFR ratio, were investigated. The Rh-embedded catalyst exhibited a significantly high turnover frequency (TOF~204 h−1) superior to that of Ru, Pd, or Ni-based catalysts on KIT-6. A plausible reaction mechanism was proposed after examining an independent FA decomposition reaction over the same Rh-ED-KIT-6 catalyst. The heterogeneity of the catalyst was verified by a hot filtering experiment. The Rh/ED-KIT-6 could be reused for up to three cycles without any decrease in catalytic activity and selectivity, but the slow oxidation of Rh species was detected.

A porous dual-functional acid-base covalent organic polymer catalyst (CBAP-1(EDA-SO 3 H)) was prepared using a facile Friedel-Crafts reaction of triphenylbenzene and terephthaloyl chloride to prepare the polymer backbone (CBAP-1) followed by functionalization with ethylenediamine (EDA) and a simple chlorosulfonic acid treatment. The resultant polymeric catalyst and its functional moieties were characterized by Fourier transform infrared (FTIR), elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and N 2 adsorption-desorption isotherm analyses. The catalytic activity of CBAP-1(EDA-SO 3 H) was then assessed for one-pot cascade C C bond-forming reactions involving deacetylation-Knoevenagel condensation and Henry reactions. Compared with the homogeneous catalyst and CBAP-1 functionalized with just acid or base, CBAP-1(EDA-SO 3 H) showed superior catalytic activity and selectivity, and was found to be reusable for up to seven consecutive runs. A catalytic mechanism for C C bond-forming reactions over CBAP-1(EDA-SO 3 H) was proposed.

Although exfoliated HNb 3 O 8 nanosheet (e-HNb 3 O 8 ) is known to be a powerful catalyst in acid-catalyzed reactions, the preparation technique has limitations in its high-yield production. We herein report the enhanced exfoliation efficiency and recovery of e-HNb 3 O 8 by contacting Nb 2 O 5 solid with a diluted K 2 CO 3 solution before ball milling (mechanochemical activation). The so-obtained e-HNb 3 O 8 showed a larger specific surface area, a higher density of total acid sites and an improved catalytic performance in the dehydration of 2-heptanol and formic acid, compared to the corresponding sample prepared by the conventional solid-state mixing. The ball-milled K 2 CO 3 –Nb 2 O 5 mixtures, layered KNb 3 O 8 , ion-exchanged HNb 3 O 8 and exfoliated HNb 3 O 8 samples were characterized by PXRD, TEM-EDS, TGA-MS and SEM-EDS. The characterization results revealed more intercalated K + ions in KNb 3 O 8 particles as well as more homogeneous K 2 CO 3 –Nb 2 O 5 mixture when the employed preparation technique was used. This is achieved by more infiltration of K 2 CO 3 into Nb 2 O 5 lattice before ball milling, thereby resulting in the above positive findings. Therefore, our approach has great potential to be extended to other niobate-containing nanosheet-type materials.

A new cross-linked aromatic porous polymer (CAPP) from bifonazole and 4,4′-bis(bromomethyl)biphenyl was prepared and functionalized with diethyltriamine (DETA). The product CAPP-DETA was applied as a catalyst for the removal of thiophenic sulfur compounds via oxidative desulfurization: 100% conversion of dibenzothiophene (DBT) was achieved with 50 mg of CAPP-DETA for 400 ppm DBT in decane at 120 °C after 4 h using O2 as the oxidant. The reaction was carried out under different reaction conditions of temperature (80 to 140 °C), catalyst amount (10 to 50 mg), and concentration (200 to 1000 ppm). Radical scavenger experiments indicated the reaction involving the triamine functionality in the catalyst generating the superoxide (O2•-) radicals. The conversion efficiency among the thiophenic compounds followed a sequence of dibenzothiophene > benzothiophene > thiophene. The catalyst was reusable for four repetitive cycles without deterioration in catalytic activity.

While formic acid dehydrogenation has become one of the most promising strategies for hydrogen storage, the crucial factors for realizing an efficient catalyst remain controversial. In this study, a range of Pd/C catalysts were systematically prepared by adopting either diverse metal deposition methods or different acid treatments, and the resulting catalysts were used for formic acid dehydrogenation under ambient conditions without additives. The volcano-type dependence of the activity on the Pd particle size, rate enhancement over Pd with smaller [111]/[200] ratios, and superior activity of Pd0 or Pd0/Pd(OH)2 mixture to Pd2+ clearly indicate that not only the particle size but also the surface structure or electronic states of active metal would be of prime importance to promote the reaction. Moreover, another volcano relation between the activity and the pH of a reaction solution determined by the functional groups of an acid-treated support obviously suggests that the catalytic activity is very sensitive to pH, and that a neutral reaction solution is preferred to maximize the catalytic performance. The unprecedented critical effect of a support on the catalytic performance may be rationalized in terms of two factors: (i) recombination of the formate ion with a proton and/or delay of formic acid deprotonation by excess protons in an acidic solution; (ii) competitive adsorption between the formate and hydroxyl ions in a basic solution. Therefore, tuning the nature of a support to achieve a balance between the two competitive factors is important to enhance the catalytic performance.

A new catalyst comprising Pd nanoparticles (NPs) supported on a microporous covalent triazine-based polymer (Pd/MCTP-1) was synthesized and applied for H2 production via formic acid decomposition under ambient conditions without additives. The catalytic activity of Pd/MCTP-1 was found to be superior to those of the recently reported highly active Pd/MOF catalysts, Pd/C, and Pd/SBA-15, which may be attributed to two factors: i) the formation of monodisperse and smaller Pd NPs on MCTP-1 and ii) the neutral pH of the reaction medium attained in the presence of Pd/MCTP-1. Pd/MCTP-1 is highly stable and its catalytic activity was maintained without losses for three recycle runs.

The synthesis of metal-organic frameworks (MOFs) with in-built porphyrin units remains challenging. It takes long synthesis time under carefully controlled reaction conditions, and a mixed-phase with different crystal morphologies is still frequently observed. In this work, Zr-based porphyrinic MOF-525 and MOF-545 in high purity and uniform size were produced through a sonochemical route in 2.5 and 0.5 h, respectively, using zirconyl chloride octahydrate and tetrakis (4-carboxyphenyl) porphyrin. Benzoic acid was used as a modulator for MOF-525, and trifluoroacetic acid for MOF-545. The physicochemical properties of the MOF products were examined by X-ray diffraction, scanning electron microscopy, and N2 adsorption-desorption isotherms. Additionally, the defect sites in the MOF samples were analyzed by UV–vis spectrometry, thermogravimetric analysis, and inductively coupled plasma mass spectrometer. The sonochemically synthesized MOF samples had more defect sites than the conventionally prepared ones and exhibited improved textural properties. In particular, the MOF-545 had a significantly smaller (ca. 1.0 μm) particle size than the conventionally prepared sample (ca. 4.8 μm). The MOF-525 and MOF-545 prepared by the sonochemical route exhibited enhanced hydrolysis of the chemical warfare simulant dimethyl-4-nitrophenyl phosphate (DMNP) and a faster and higher bisphenol-A adsorption than the conventionally prepared MOF samples.

Although carbon-supported palladium catalysts have been generally used for the direct synthesis of H2O2 (DSHP), the low H2O2 selectivity remains a challenge. In this work, it was systematically studied how the sulfonated carbon surface affects the physicochemical properties of Pd during catalyst preparation, and thereby affects the catalytic activity of Pd/C for the DSHP reaction. Nano-sized Pd particles (about 2–3 nm) with a high Pd2+/Pd0 ratio resulted in a high H2O2 selectivity. The sulfonated carbon material acted as an efficient solid acid support and enhanced the H2O2 selectivity. Fine-tuning the Pd properties on the sulfonated carbon support significantly improved the H2O2 selectivity by as much as 87 % in the absence of caustic promoters, which clearly demonstrates that the synergistic combination of the active metal properties and that of the carbon support are extremely important to realize a highly active and selective carbon-supported palladium catalyst for the DSHP reaction.

Ultrathin two-dimensional metal oxide nanosheets have drawn attention as potential solid acid catalysts owing to their strong acidity, attributed to the bridged OH groups formed on the nanosheets. In this study, a new class of bifunctional acid–metal catalyst was realized by the deposition of Pd on layered niobium oxide (KNb3O8 and HNb3O8) or its exfoliated nanosheet (Pd/HNb3O8-NS) and applied to one-pot cascade deacetalization and hydrogenation. It was found that the acid strength of the support exerted a large influence not only on the promotion of the first deacetalization step, but also on the acceleration of the subsequent hydrogenation step. Comparative experiments using a series of Pd/HZSM-5 catalysts with different acidities reconfirmed the crucial role of acid strength on hydrogenation. However, the superior catalytic activity of Pd/HNb3O8-NS for hydrogenation compared to that of Pd/HZSM-5 of similar acidity suggests a more efficient ensemble effect of the strong acid sites with the nearby metal sites on the nanosheet surface. Among the catalysts used, Pd/HNb3O8-NS showed the best catalytic performance for one-pot cascade reaction affording the desired product (benzyl alcohol) in approximately 92% yield, which was 7.1 and 1.2 times higher than that of layered Pd/KNb3O8 or Pd/HNb3O8, respectively. The excellent catalytic performance of Pd/HNb3O8-NS may result from the characteristic features of nanosheets: (i) the synergistic cooperation between the bifunctional active sites and (ii) the two-dimensional open surface offering easier access of the reactants to the active sites. Although the use of NaBH4 as hydrogen source was effective in improving the initial reaction performance, the basic nature of NaBH4 adversely resulted in weakening the acid strength of the catalyst, and consequently led to a reduction in catalytic activity.

A two-dimensional layered niobium oxide and its exfoliated nanosheet were examined as potential solid acid supports for direct synthesis of hydrogen peroxide from hydrogen and oxygen under intrinsically safe and noncorrosive reaction conditions. The catalytic performance strongly depended on the acid strength of the support material. The Pd-supported protonated niobium oxide nanosheet catalyst (Pd/HNb3O8-NS) with remarkably enhanced acidity was superior to layered Pd/KNb3O8 or Pd/HNb3O8 to promote the reaction. Hydrogen peroxide decomposition testing revealed that, although HNb3O8 was comparable to its exfoliated counterpart, HNb3O8-NS, in suppressing hydrogen peroxide decomposition without hydrogen, HNb3O8 was virtually ineffective in preventing hydrogen peroxide hydrogenation in the presence of hydrogen. However, compared with HNb3O8, HNb3O8-NS was found to be still effective at suppressing hydrogen peroxide hydrogenation. The different efficiency observed between HNb3O8 and HNb3O8-NS in the prevention of hydrogen peroxide hydrogenation implies that use of a highly acidic support is advantageous to effectively suppress faster and therefore more unfavorable hydrogen peroxide hydrogenation compared with decomposition. This result clearly demonstrates that the highly acidic HNb3O8 nanosheet can serve as an efficient solid acid support for direct synthesis of hydrogen peroxide from hydrogen and oxygen.

There is an urgent need to provide adequate and sustainable supplies of water and food to satisfy the demand of an increasing population. Catalysis plays important roles in meeting these needs by facilitating the synthesis of hydrogen peroxide that is used in water decontamination and chemicals production, and ammonia that is used as fertilizer. However, these chemicals are currently produced with processes that are either very energy-intensive or environmentally unfriendly. This article offers the perspectives of the challenges and opportunities in the production of these chemicals, focusing on the roles of catalysis in more sustainable, alternative production methods that minimize energy consumption and environmental impact. While not intended to be a comprehensive review, the article provides a critical review of selected literature relevant to its objectives, discusses areas needed for further research, and potential new directions inspired by new developments in related fields. For each chemical, production by thermal, electro-, and photo-excited processes are discussed. Problems that are common to these approaches and their differences are identified and possible solutions suggested.

Background Humans are exposed to low-dose bisphenol A (BPA) through plastic consumer products and dental sealants containing BPA. Although a number of studies have investigated the mammary gland effects after high-dose BPA exposure, the study findings differ. Furthermore, there has been a lack of mechanistic studies. Objective The objective of this study was to investigate the effect and the mechanism of low-dose BPA in mammary gland cells. Methods We evaluated DNA damage following BPA exposure using the comet assay and immunofluorescence staining, and used cell counting and three-dimensional cultures to evaluate effects on proliferation. We examined the expressions of markers of DNA damage and cell-cycle regulators by immunoblotting and performed siRNA-mediated gene silencing to determine the role of c-Myc in regulating BPA’s effects. Results Low-dose BPA significantly promoted DNA damage, up-regulated c-Myc and other cell-cycle regulatory proteins, and induced proliferation in parallel in estrogen receptor-α (ERα)-negative mammary cells. Silencing c-Myc diminished these BPA-induced cellular events, suggesting that c-Myc is essential for regulating effects of BPA on DNA damage and proliferation in mammary cells. Conclusions Low-dose BPA exerted c-Myc–dependent genotoxic and mitogenic effects on ERα-negative mammary cells. These findings provide significant evidence of adverse effects of low-dose BPA on mammary cells. Citation Pfeifer D, Chung YM, Hu MC. 2015. Effects of low-dose bisphenol A on DNA damage and proliferation of breast cells: the role of c-Myc. Environ Health Perspect 123:1271–1279; http://dx.doi.org/10.1289/ehp.1409199

Pd-supported metal-organic framework (MOF) catalysts have been applied for the direct synthesis of H2O2 from H2 and O2 under intrinsically safe and noncorrosive reaction conditions. The catalytic performance was strongly governed by the properties of the support materials, and the Bronsted acid sites newly introduced on the organic linkers of MOF were proven to be more effective than the Lewis acid sites on the open metal sites in enhancing the H2O2 formation and suppressing its decomposition. Pd/MIL-101-SO3H was highly efficient in promoting the reaction owing to the contribution from the strong acidity and highly porous nature of the robust MOF support used. The hydrogen peroxide productivity of Pd/MIL-101-SO3H catalyst reached 361 mmol H2O2 mmol/Pd/h, which was 2.3 or 1.7 times higher than that of the conventional Pd/HBEA (SAR = 25) or Pd/sulfonated resin catalyst, respectively. This result clearly demonstrates the promising potential of MOF as a solid acid support material.

COH29 [N-(4-(3,4-dihydroxyphenyl)-5-phenylthiazol-2-yl)-3,4-dihydroxybenzamide], a novel antimetabolite drug developed at City of Hope Cancer Center, has anticancer activity that stems primarily from the inhibition of human ribonucleotide reductase (RNR). This key enzyme in deoxyribonucleotide biosynthesis is the target of established clinical agents such as hydroxyurea and gemcitabine because of its critical role in DNA replication and repair. Herein we report that BRCA-1-defective human breast cancer cells are more sensitive than wild-type BRCA-1 counterparts to COH29 in vitro and in vivo. Microarray gene expression profiling showed that COH29 reduces the expression of DNA repair pathway genes, suggesting that COH29 interferes with these pathways. It is well established that BRCA1 plays a role in DNA damage repair, especially homologous recombination (HR) repair, to maintain genome integrity. In BRCA1-defective HCC1937 breast cancer cells, COH29 induced more double-strand breaks (DSBs) and DNA-damage response than in HCC1937 + BRCA1 cells. By EJ5- and DR-green fluorescent protein (GFP) reporter assay, we found that COH29 could inhibit nonhomologous end joining (NHEJ) efficiency and that no HR activity was detected in HCC1937 cells, suggesting that repression of the NHEJ repair pathway may be involved in COH29-induced DSBs in BRCA1-deficient HCC1937 cells. Furthermore, we observed an accumulation of nuclear Rad51 foci in COH29-treated HCC1937 + BRCA1 cells, suggesting that BRCA1 plays a crucial role in repairing and recovering drug-induced DNA damage by recruiting Rad51 to damage sites. In summary, we describe here additional biologic effects of the RNR inhibitor COH29 that potentially strengthen its use as an anticancer agent.

Ursolic acid (UA) supplementation was previously shown to improve skeletal muscle function in resistance-trained men. This study aimed to determine, using the same experimental paradigm, whether UA also has beneficial effects on exercise-induced skeletal muscle damage markers including the levels of cortisol, B-type natriuretic peptide (BNP), myoglobin, creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) in resistance-trained men. Sixteen healthy participants were randomly assigned to resistance training (RT) or RT+UA groups (n=8 per group). Participants were trained according to the RT program (60~80% of 1 repetition, 6 times/week), and the UA group was additionally given UA supplementation (450 mg/day) for 8 weeks. Blood samples were obtained before and after intervention, and cortisol, BNP, myoglobin, CK, CK-MB, and LDH levels were analyzed. Subjects who underwent RT alone showed no significant change in body composition and markers of skeletal muscle damage, whereas RT+UA group showed slightly decreased body weight and body fat percentage and slightly increased lean body mass, but without statistical significance. In addition, UA supplementation significantly decreased the BNP, CK, CK-MB, and LDH levels (p

In this study, a sulfonated Zr-terephthalate metal-organic framework (MOF) (UiO-66-SO3H) was prepared using two different methods: post-synthetic grafting onto the Zr open metal sites and direct solvothermal method using monosodium 2-sulfoterephthalate. Their catalytic activities for the acid-catalyzed Friedel–Crafts acylation of p-xylene with benzoyl chloride were compared. The physicochemical properties and catalytic performance of the functionalized MOF structure was found to be strongly dependent on the synthesis scheme. UiO-66-SO3H prepared by a direct solvothermal route exhibited excellent catalytic activity and stability compared to that prepared by post-synthetic grafting.

광학 및 형광 현미경을 이용한 실시간 촉매 모니터링 기술을 활용하여 C5 파라핀과 올레핀의 방향족화 반응 중 H-ZSM-5 촉매 표면에서 발생하는 코크 형성 과정을 시간별, 촉매 위치별로 관찰하였다. 실시간 자외-가시광 분광현미경(in-situ UV-vis microspectroscopy) 실험을 통해 반응 중 촉매 표면에서 발생하는 코킹 현상에 대한 정보를 실시간으로 얻을 수 있었으며, 그 결과, 결정의 위치와 반응물의 종류에 따라 코크 형성이 크게 달라짐을 확인하였다. 실시간 공초점형 형광현미경(in-situ confocal fluorescence microscopy) 연구에서는, 488 nm 레이저에 의해 형광을 나타내는 화학종들은 높은 분포로 결정의 중앙부분에 존재하며, 561 nm 레이저에 의해 형광을 발현하는 화학종들은 촉매 결정의 외곽으로 이동하는 것을 관찰하였다. 이러한 결과는, 코크 전구체의 크기에 따라 형광 발현 현상이 다르며, 따라서, 촉매의 위치에 따라 다른 종류의 코크 전구체가 존재한다는 것을 시사한다.

Palladium catalysts supported on HZSM-5 (Pd/HZSM-5-X (X = 15, 30, 75, 100, and 150)) were prepared with a variation of Si/Al molar ratio (X), and they were applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. Conversion of hydrogen over Pd/HZSM-5-X catalysts showed no great difference, while selectivity for hydrogen peroxide over the catalysts exhibited a volcano-shaped curve with respect to Si/Al molar ratio. As a consequence, yield for hydrogen peroxide over the catalysts showed a volcano-shaped curve with respect to Si/Al molar ratio. Yield for hydrogen peroxide over Pd/HZSM-5-X catalysts was closely related to the Bronsted acidity/Lewis acidity (B/L) ratio of the catalysts. Yield for hydrogen peroxide increased with increasing B/L ratio of Pd/HZSM-5-X catalysts. This indicates that Bronsted acid sites of Pd/HZSM-5-X catalysts played an important role for enhancing the catalytic performance in the direct synthesis of hydrogen peroxide. Furthermore, yield for hydrogen peroxide increased with increasing Bronsted acidity of Pd/HZSM-5-X catalysts. Among the catalysts tested, Pd/HZSM-5-30 catalyst with the largest Bronsted acidity showed the highest yield for hydrogen peroxide. Therefore, it is concluded that Bronsted acidity of Pd/HZSM-5-X catalysts served as an important factor determining the catalytic performance in the direct synthesis of hydrogen peroxide.

// See-Hyoung Park 1, 2, * , Young Min Chung 1, * , Jessica Ma 1 , Qin Yang 3 , Jonathan S. Berek 1 , Mickey C-T. Hu 1 1 Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA 94305, USA 2 Current address: Department of Biological and Chemical Engineering, Hongik University, Sejong, 339-701, Korea 3 Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, MO 63108, USA * These authors contributed equally to this work Correspondence to: Mickey C-T. Hu, email: mhu1@stanford.edu Keywords: FOXO3, breast cancer, bepridil, trifluoperazine, dopamine receptor Received: January 18, 2016 Accepted: May 12, 2016 Published: June 07, 2016 ABSTRACT Triple-negative breast cancer (TNBC) is the most lethal form of breast cancer. Lacking effective therapeutic options hinders treatment of TNBC. Here, we show that bepridil (BPD) and trifluoperazine (TFP), which are FDA-approved drugs for treatment of schizophrenia and angina respectively, inhibit Akt-pS473 phosphorylation and promote FOXO3 nuclear localization and activation in TNBC cells. BPD and TFP inhibit survival and proliferation in TNBC cells and suppress the growth of TNBC tumors, whereas silencing FOXO3 reduces the BPD- and TFP-mediated suppression of survival in TNBC cells. While BPD and TFP decrease the expression of oncogenic c-Myc, KLF5, and dopamine receptor DRD2 in TNBC cells, silencing FOXO3 diminishes BPD- and TFP-mediated repression of the expression of these proteins in TNBC cells. Since c-Myc, KLF5, and DRD2 have been suggested to increase cancer stem cell-like populations in various tumors, reducing these proteins in response to BPD and TFP suggests a novel FOXO3-dependent mechanism underlying BPD- and TFP-induced apoptosis in TNBC cells.

The direct synthesis of hydrogen peroxide (DSHP) from H2 and O2 is conceptually the most ideal and straightforward reaction for producing H2O2 in industry. However, precisely tailored catalysts are...

Palladium catalysts supported on Cs2.5H0.5PW12O40-incorporated MCF silica (Pd/CsPW-MCF-X (X = 14.3, 21.8, 28.1, 33.4, and 38.0)) were prepared with a variation of Cs2.5H0.5PW12O40 content (X, wt.%). The prepared catalysts were then applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. Selectivity for hydrogen peroxide and yield for hydrogen peroxide over Pd/CsPW-MCF-X catalysts showed volcano-shaped curves with respect to Cs2.5H0.5PW12O40 content. Acidity of the catalysts also showed a volcano-shaped trend with respect to Cs2.5H0.5PW12O40 content. It was revealed that yield for hydrogen peroxide increased with increasing acidity of Pd/CsPW-MCF-X catalyst. Pd/CsPW-MCF-X efficiently served as an alternate acid source and as an active metal catalyst in the direct synthesis of hydrogen peroxide from hydrogen and oxygen.

Highly monodisperse carbon-supported palladium nanoparticles with controllable size (3 nm, 6.5 nm, 9.5 nm) were prepared using a simple colloidal method, and the size dependence of the catalytic performance for the direct synthesis of hydrogen peroxide from hydrogen and oxygen was studied. Smaller-sized supported palladium nanoparticles showed both higher conversion of hydrogen and selectivity for hydrogen peroxide, compared to larger-sized supported particles. Among the catalysts tested, 3-nm Pd nanoparticles supported on carbon showed the highest yield for hydrogen peroxide because of the small size and high crystallinity.

Palladium catalysts supported on CsXH3−XPW12O40/MCF (Pd/CsXPW/MCF (X = 1.7, 2.0, 2.2, 2.5, and 2.7)) were prepared with a variation of cesium content (X), and they were applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. Conversion of hydrogen over Pd/CsXPW/MCF catalysts showed no great difference, while selectivity for hydrogen peroxide and yield for hydrogen peroxide over the catalysts showed volcano-shaped curves with respect to cesium content. Acidity of Pd/CsXPW/MCF catalysts also showed a volcano-shaped trend with respect to cesium content. It was revealed that yield for hydrogen peroxide increased with increasing acidity of Pd/CsXPW/MCF catalysts. Among the catalysts tested, Pd/Cs2.5PW/MCF catalyst with the largest acidity showed the highest yield for hydrogen peroxide. It is concluded that Pd/CsXPW/MCF efficiently served as an alternate acid source and as an active metal catalyst in the direct synthesis of hydrogen peroxide.

The cellular response to double-strand breaks (DSBs) in DNA is a complex signalling network, mobilized by the nuclear protein kinase ataxia-telangiectasia mutated (ATM), which phosphorylates many factors in the various branches of this network. A main question is how ATM regulates DSB repair. Here, we identify the DNA repair enzyme polynucleotide kinase/phosphatase (PNKP) as an ATM target. PNKP phosphorylates 5'-OH and dephosphorylates 3'-phosphate DNA ends that are formed at DSB termini caused by DNA-damaging agents, thereby regenerating legitimate ends for further processing. We establish that the ATM phosphorylation targets on human PNKP-Ser 114 and Ser 126-are crucial for cellular survival following DSB induction and for effective DSB repair, being essential for damage-induced enhancement of the activity of PNKP and its proper accumulation at the sites of DNA damage. These findings show a direct functional link between ATM and the DSB-repair machinery.

Palladium catalysts supported on SO3H-functionalized MCF silica (Pd/SO3H-MCF-T (T=450, 550, 650, 750, 850, and 950)) were prepared with a variation of calcination temperature (T, °C) of MCF silica. They were then applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. Conversion of hydrogen, selectivity for hydrogen peroxide, and yield for hydrogen peroxide showed volcano-shaped curves with respect to calcination temperature of MCF silica. Yield for hydrogen peroxide increased with increasing acid density of Pd/SO3H-MCF-T catalysts. Thus, acid density of Pd/SO3H-MCF-T catalysts played an important role in determining the catalytic performance in the direct synthesis of hydrogen peroxide. Pd/SO3H-MCF-T catalysts efficiently served as an acid source and as an active metal catalyst in the direct synthesis of hydrogen peroxide.

The direct conversion of cellulose into polyols such as ethylene glycol and propylene glycol was examined over Pt catalysts supported on H-ZSM-5 with different SiO2/Al2O3 molar ratios. The Pt dispersion, determined by CO chemisorption and transmission electron microscopy (TEM), as well as the surface acid concentration measured by the temperature-programmed desorption of ammonia (NH3-TPD), increased with decreasing SiO2/Al2O3 molar ratio for Pt/H-ZSM-5. The total yield of the polyols, i.e., sorbitol, manitol, ethylene glycol and propylene glycol, generally increased with increasing Pt dispersion in Pt/H-ZSM-5. The one-pot aqueous-phase reforming of cellulose into H2 was also examined over the same catalysts. The Pt catalyst supported on H-ZSM-5 with a moderate SiO2/Al2O3 molar ratio and a large external surface area showed the highest H2 production rate. The Pt dispersion, surface acidity, external surface area and surface hydrophilicity appear to affect the catalytic activity for this reaction.

Palladium catalysts supported on H 3 PW 12 O 40 heteropolyacid incorporated into MCF silica (Pd/HPW-MCF- X ( X = 1.0, 4.8, 9.1, 13.0, 16.7, 20.0, 23.1, and 25.9)) were prepared with a variation of H 3 PW 12 O 40 content ( X , wt.%). The prepared catalysts were then applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. Conversion of hydrogen over Pd/HPW-MCF- X catalysts showed no great difference, while selectivity for hydrogen peroxide and yield for hydrogen peroxide over the catalysts showed volcano-shaped curves with respect to H 3 PW 12 O 40 content. Acidity of Pd/HPW-MCF- X catalysts also showed a volcano-shaped trend with respect to H 3 PW 12 O 40 content. It was observed that yield for hydrogen peroxide increased with increasing acidity of Pd/HPW-MCF- X catalyst. Thus, acidity of Pd/HPW-MCF- X catalyst played an important role in determining the catalytic performance in the direct synthesis of hydrogen peroxide. HPW-MCF- X support efficiently served as an alternate acid source in the direct synthesis of hydrogen peroxide.

The DNA damage response (DDR) is a complex signaling network that leads to damage repair while modulating numerous cellular processes. DNA double-strand breaks (DSBs)-a highly cytotoxic DNA lesion-activate this system most vigorously. The DSB response network is orchestrated by the ATM protein kinase, which phosphorylates key players in its various branches. Proteasome-mediated protein degradation plays an important role in the proteome dynamics following DNA damage induction. Here, we identify the nuclear proteasome activator PA28 gamma (REG gamma; PSME3) as a novel DDR player. PA28 gamma depletion leads to cellular radiomimetic sensitivity and a marked delay in DSB repair. Specifically, PA28 gamma deficiency abrogates the balance between the two major DSB repair pathways-nonhomologous end-joining and homologous recombination repair. Furthermore, PA28 gamma is found to be an ATM target, being recruited to the DNA damage sites and required for rapid accumulation of proteasomes at these sites. Our data reveal a novel ATM-PA28 gamma-proteasome axis of the DDR that is required for timely coordination of DSB repair.

Palladium-containing insoluble heteropolyacid (HPA) catalysts (Pd0.15M2.5H0.2PW12O40) were prepared by an ion-exchange method using various alkaline metal ions (M = K+, Rb+, and Cs+) (denoted as Pd-KPW, Pd-RbPW, and Pd-CsPW). They were then applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. Conversion of hydrogen over the catalysts was almost identical with no great difference, while selectivity for hydrogen peroxide increased in the order of Pd-KPW < Pd-RbPW < Pd-CsPW. As a consequence, yield for hydrogen peroxide increased in the order of Pd-KPW < Pd-RbPW < Pd-CsPW. It was found that yield for hydrogen peroxide increased with increasing Pd 3d5/2 binding energy of the catalyst. Among the catalysts tested, Pd-CsPW catalyst with the highest Pd 3d5/2 binding energy showed the highest yield for hydrogen peroxide.

Palladium catalysts supported on SO 3 H-functionalized mesoporous silicas (denoted as Pd/SO 3 H-MCM-41, Pd/SO 3 H-MCM-48, Pd/SO 3 H-MSU-1, Pd/SO 3 H-SBA-15, and Pd/SO 3 H-MCF) were applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. For comparison, palladium catalysts supported on mesoporous silicas (denoted as Pd/MCM-41, Pd/MCM-48, Pd/MSU-1, Pd/SBA-15, and Pd/MCF) were also employed for the direct synthesis of hydrogen peroxide. Selectivity for hydrogen peroxide, yield for hydrogen peroxide, and final concentration of hydrogen peroxide over Pd/SO 3 H-functionalized mesoporous silica catalysts were much higher than those over Pd/mesoporous silica catalysts. Yield for hydrogen peroxide increased with increasing acid density of Pd/SO 3 H-functionalized mesoporous silica. Pd/SO 3 H-functionalized mesoporous silicas efficiently served as an alternate acid source and as an active metal catalyst in the direct synthesis of hydrogen peroxide from hydrogen and oxygen.

Carbon nano-coated LiNi0.8Co0.15Al0.05O2/C (LNCAO/C) cathode-active materials were prepared by a sol–gel method and investigated as the cathode material for lithium ion batteries. Electrochemical properties including the galvanostatic charge–discharge ability and cyclic voltammogram behavior were measured. Cyclic voltammetry (2.7–4.8 V) showed that the carbon nano-coating improved the "formation" of the LNCAO electrode, which was related to the increased electronic conductivity between the primary particles. The carbon nano-coated LNCAO/C exhibited good electrochemical performance at high C-rate. Also, the thermal stability at a highly oxidized state of the carbon nano-coated LNCAO was remarkably enhanced. The carbon nano-coating layer can serve as a physical and/or (electro-)chemical protection shell for the underlying LNCAO, which is attributed to an increase of the grain connectivity (physical part) and also to the protection of metal oxide from chemical reactions (chemical part).

This study presents a method for the fabrication of solvent-resistant poly(dimethylsiloxane) (PDMS) microfluidic devices by coating the microfluidic channel with a hybrid inorganic/organic polymer (HR4). This modification dramatically increases the resistance of PDMS microfluidic channels to various solvents, because it leads to a significant reduction in the rate of solvent absorption and consequent swelling. The compatibility of modified PDMS with a wide range of solvents is investigated by evaluating the swelling ratio measured through weight changes in a standard block. The HR4-modified PDMS microfluidic device can be applied to the formation of water-in-oil (W/O) and oil-in-water (O/W) emulsions. The generation of organic solvent droplets with high monodispersity in the microfluidic device without swelling problems is demonstrated. The advantage ofthis proposed method is that it can be used to rapidly fabricate microfluidic devices using the bulk properties of PDMS, while also increasing their resistance to various organic solvents. This high compatibility with a variety of solvents of HR4-modified PDMS can expand the application of microfluidic systems to many research fields.

TiO 2 –ZrO 2 (TZ- X ( X = 0, 25, 50, 75, and 100)) supports were prepared by a co-precipitation method with a variation of ZrO 2 content ( X , mol%). Pd/TiO 2 –ZrO 2 (Pd/TZ- X ) catalysts prepared by an incipient wetness method were then applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. It was revealed that both total acidity and surface acidity of Pd/TZ- X catalysts played an important role in determining the catalytic performance in the direct synthesis of hydrogen peroxide. Among the catalysts tested, Pd/TZ-75 catalyst with the largest total acidity and the largest surface acidity showed the highest yield for hydrogen peroxide.

Oxidative dehydrogenation of n-butene to 1,3-butadiene over ZnFe2O4 catalyst mixed with CsxH3−xPW12O40 heteropolyacid (HPA) was performed in a continuous flow fixed-bed reactor. The effect of CsxH3−xPW12O40 addition on the catalytic performance of ZnFe2O4 was investigated. CsxH3−xPW12O40 itself showed very low catalytic performance in the oxidative dehydrogenation of n-butene. However, addition of small amount of CsxH3−xPW12O40 into ZnFe2O4 enhanced the catalytic performance of ZnFe2O4 catalyst. The catalytic performance of ZnFe2O4-CsxH3−xPW12O40 mixed catalysts was closely related to the surface acidity of CsxH3−xPW12O40. Among the catalysts tested, ZnFe2O4-Cs2.5H0.5 PW12O40 mixed catalyst showed the best catalytic performance. Strong acid strength and large surface acidity of Cs2.5H0.5PW12O40 was responsible for high catalytic performance of ZnFe2O4-Cs2.5H0.5PW12O40 mixed catalyst. Thus, Cs2.5H0.5PW12O40 could be utilized as an efficient promoter and diluent in formulating ZnFe2O4 catalyst for the oxidative dehydrogenation of n-butene.

ZnMeIIIFeO4 catalysts with different trivalent metal (MeIII = Fe, Al, Cr, Mn, and Co) were prepared by a co-precipitation method, and were applied to the oxidative dehydrogenation of n-butene to 1,3-butadiene. Successful formation of ZnMeIIIFeO4 catalysts was confirmed by XRD and ICP-AES analyses. Catalytic performance of ZnMeIIIFeO4 catalysts in the oxidative dehydrogenation of n-butene strongly depended on the identity of trivalent metal (MeIII). Acid properties of ZnMeIIIFeO4 catalysts were measured by NH3-TPD experiments, with an aim of correlating the catalytic performance with the surface acid property of the catalysts. It was revealed that yield for 1,3-butadiene increased with increasing surface weak-acid density of ZnMeIIIFeO4 catalyst. Among the catalysts tested, ZnFeFeO4 catalyst with the largest surface weak-acid density showed the best catalytic performance in the oxidative dehydrogenation of n-butene.

Palladium catalyst supported on SO3H-functionalized SBA-15 (denoted as Pd/SO3H-SBA-15) was applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. For comparison, palladium catalyst supported on SBA-15 (denoted as Pd/SBA-15) was also employed for the direct synthesis of hydrogen peroxide. Selectivity for hydrogen peroxide, yield for hydrogen peroxide, and final concentration of hydrogen peroxide over Pd/SO3H-SBA-15 catalyst were much higher than those over Pd/SBA-15 catalyst. The high catalytic performance of Pd/SO3H-SBA-15 catalyst was attributed to the enhanced acid amount of SO3H-SBA-15 support, which served as an alternate acid source in the direct synthesis of hydrogen peroxide from hydrogen and oxygen.