Competing E3 ubiquitin ligases govern circadian periodicity by degradation of CRY in nucleus and cytoplasm.

Period determination in the mammalian circadian clock involves the turnover rate of the repressors CRY and PER. We show that CRY ubiquitination engages two competing E3 ligase complexes that either lengthen or shorten circadian period in mice. Cloning of a short-period circadian mutant, Past-time, revealed a glycine to glutamate missense mutation in Fbxl21, an F-box protein gene that is a paralog of Fbxl3 that targets the CRY proteins for degradation. While loss of function of FBXL3 leads to period lengthening, mutation of Fbxl21 causes period shortening. FBXL21 forms an SCF E3 ligase complex that slowly degrades CRY in the cytoplasm but antagonizes the stronger E3 ligase activity of FBXL3 in the nucleus. FBXL21 plays a dual role: protecting CRY from FBXL3 degradation in the nucleus and promoting CRY degradation within the cytoplasm. Thus, the balance and cellular compartmentalization of competing E3 ligases for CRY determine circadian period of the clock in mammals.

Fluorescent and Catalytic Properties of a 2D Lamellar Zn Metal-Organic Framework with sql Network Structure.

A two-dimensional (2D) lamellar Zn metal-organic framework (Zn-MOF, 1) with a fluorescent 1,6-di(pyridin-3-yl)pyrene (3-DPPy) and 1,4-benzenedicarboxylate (BDC2-) bridging linkers was prepared and structurally characterized. The chemical formula of 1 is [Zn(µ-3-DPPy)(µ-BDC)]n. The mononuclear Zn(II) ion, acting as a node, is tetrahedrally coordinated with two 3-DPPy and two BDC linkers. The coordination environment of Zn(II) is a distorted tetrahedral geometry. The Zn-MOF is the sql network structure based on topology analysis. The undulated 2D sheets of 1 tightly pack together to form a lamellar structure. The pyrene moieties are parallelly oriented to each other. The Zn-MOF is not porous, possibly because the mononuclear Zn(II) node did not form cluster-based secondary building units due to the less symmetric 3-DPPy. The steady-state fluorescence measurements indicate that the fluorescence signal of the 1 is slightly blue-shifted compared to the free 3-DPPy in the solid state. The excimer emission band at 463 nm for crystalline 3-DPPy is shifted to 447 nm for 1. The value of 447 nm is also a blue-shift value compared to nonsubstituted pyrene crystals (470 nm). Despite its nonporosity, the surface Lewis acidic sites of 1 could catalyze the transesterification of esters. Surface defect sites are responsible for this catalytic activity.

Photophysical Properties and Heterogeneous Photoredox Catalytic Activities of Ru(bpy)3 @InBTB Metal-Organic Framework (MOF).

Metal-organic frameworks (MOFs) with negatively charged frameworks are suitable for selectively encapsulating cationic guest ions via a cation-exchange process. Encapsulating photoactive [RuL3 ]2+ polypyridine complexes into the preorganized mesoscale channels of a MOF is a good method for stabilizing the excited states of the complexes. Three new RuL3 @InBTB MOFs were prepared by encapsulating cationic [Ru(bpy)3 ]2+ (bpy=2,2'-bipyridine), [Ru(phen)3 ]2+ (phen=1,10-phenanthroline), and [Ru(bpz)3 ]2+ (bpz=2,2'-bipyrazine) into the mesopores of a three-dimensional (3D) InBTB MOF (H3 BTB=1,3,5-benzenetribenzoic acid). The photophysical properties of the resulting materials were investigated by photoluminescence (PL) analysis. The photoredox catalytic activities were also investigated for the aza-Henry reaction, hydrogenation of dimethyl maleate, and decomposition of methyl orange under visible light irradiation at room temperature. RuL3 @InBTB MOFs were found to be very stable and highly recyclable photoredox catalytic systems.

Effects of an educational program on disaster nursing competency.

OBJECTIVE: The purpose of this study was to examine the effects of an educational program on disaster nursing competency among Korean nursing students. DESIGN AND SAMPLE: A quasi-experimental design with a nonequivalent control group was used. We randomly assigned 60 junior nursing students from two nursing colleges in Korea to an experimental group (n = 30) and a control group (n = 30). MEASURES: A disaster educational program for nursing students was developed based on the International Council of Nurses framework of disaster nursing competencies. The program sought to teach nursing activities by stage of disaster (i.e., prevention/mitigation, preparedness, response, and recovery/rehabilitation). Disaster nursing knowledge, disaster triage, and disaster readiness were measured as dependent variables. RESULTS: Compared with the control group, the experimental group showed a significant increase in disaster nursing knowledge (t = 14.37, p < 0.001), disaster triage (t = 7.90, p = 0.002), and disaster readiness (t = 10.82, p < 0.001). CONCLUSION: The disaster educational program developed in this study was effective in increasing disaster nursing competency among nursing students and is therefore a useful intervention strategy for nursing students.

Nitric and nitrous acid formation in plasma-treated water: Decisive role of nitrogen oxides (NOx=1-3).

Nitrogen fixation using low-temperature plasma, particularly in relation to plasma-treated water (PTW) and its chemical and physical properties, has received a renewed research focus. Dissolving highly concentrated nitrogen oxides (NOx = 1-3) generated by air discharge into water results in the formation of two aqueous oxiacids (nitrous and nitric acids; HNOy = 2,3) and their conjugates (nitrate and nitrite ions; NOy-). Nonlinear formation of these species in PTW with respect to plasma conditions has been observed; however, the significance of the time-varying NOx on this nonlinearity has not yet been thoroughly investigated. Here, we demonstrate real-time observations of HNOy/NOy- as well as NOx production in a surface dielectric barrier discharge reactor containing distilled water. Synchronized two optical absorption spectroscopy systems were employed to simultaneously measure gas-phase NOx and liquid-phase HNOy/NOy- in the plasma reactor operated under different oxygen contents of 5, 20, and 50%. Our results showed that reducing the oxygen content in the reactor accelerated the chemical transition from O3 and NO3 to NO1,2, leading to a predominance of nitrite in PTW. Specifically, the NO3-rich period was extended with increasing O2 content, resulting in the production of nitrate-dominant PTW at low pH levels. Our findings highlight the potential for the selective generation of HNOy/NOy- in PTW through the active and passive control of NOx in a plasma reactor. The direct, real-time observation of NOx-HNOy/NOy- conversion presented here has potential for improving the control and optimization of PTW, thereby enhancing its applicability.

Preparation of anatase/rutile mixed-phase titania nanoparticles for dye-sensitized solar cells.

Acid-labile high surface mesoporous ZnO/Zn(OH)2 composite material is used as a novel hard template for the preparation of mesoporous amorphous TiO2. The template-free amorphous TiO2 material is then thermally crystallized at suitable temperature to control the relative ratio of anatase and rutile phases in a particle. Four different anatase/rutile (AR) mixed-phase TiO2 nanoparticles (AR-3, AR-15, AR-20, and AR-23 denoted for the samples of 3%, 15%, 20%, and 23% rutile phase, respectively) are prepared and characterized by powder X-ray diffraction (PXRD) and transmission electron microscopy (TEM). The coexistence of anatase and rutile phases in a TiO2 nanoparticle is visually confirmed by HRTEM analysis. These mixed-phase TiO2 nanoparticles are examined as candidates for photoelectrodes of dye-sensitized solar cells (DSSCs). The J-V curves and IPCE spectra for the DSSCs prepared from the mixed-phase TiO2 nanoparticles are obtained, and their photovoltaic properties are investigated. The photo-conversion efficiency (eta) indicates the highest value of 5.07% for AR-20. The synergistic effect of coexisting anatase and rutile phases with an optimal ratio in a TiO2 nanoparticle of AR-20 for an efficient interfacial transfer of photo-generated electrons is likely to lead to the highest efficiency among the AR-n samples.

Intracellular protein delivery by hollow mesoporous silica capsules with a large surface hole.

We prepared cell membrane-permeable hollow mesoporous silica capsules (HMSCs) by a simple new method. CTAB micellar assembly in cholesterol emulsion gave rise to a novel capsular morphology of the HMSC particles. The HMSCs consisted of mesostructured silica walls with a large surface hole (25-50 nm) and the average particle dimension was 100-300 nm. They exhibited high surface areas of up to 719.3 m(2) g(-1) and a mesoporous range of pores of 2.4-2.7 nm. The surface-functionalized HMSCs could also be prepared by a similar co-condensation method using tetraethoxysilane with various organoalkoxysilane precursors in the presence of cholesterol. These organically modified HMSCs could be further modified on demand. For example, a carboxy-functionalized HMSC could be surface-functionalized by a green fluorescent 5-aminofluorescein (AFL) through an amidation reaction to afford a fluorescent AFL-HMSC. The hollow capsular morphology of the HMSCs with a large surface hole enabled us to develop very efficient intracellular delivery systems for membrane-impermeable ions, molecules, and various functional proteins. Non-covalent sequestration and delivery of proteins as well as covalent linkage of fluorescent molecules on the silica surface are effective for this system. The highly negatively charged green fluorescent probe mag-fluo-4 could be intracellularly delivered into HeLa cells by HMSC without any difficulty. The HMSCs could also effectively transport large functional proteins such as antibodies into HeLa cells. The efficiency of protein delivery by HMSC seems to be 3-22-fold higher than that of mesoporous silica nanospheres (MSNs) based on confocal laser scanning microscopy (CLSM) analysis.

Catalytic oxygen evolution from hydrogen peroxide by trans-[Co(en)2Cl2]@InBTB metal-organic framework catalytic system.

The diethylammonium counter-cations of the [Et2NH2]3[In3(BTB)4] metal-organic framework (InBTB MOF, BTB = 1,3,5-benzenetribenzoate) with an anionic framework can be effectively exchanged with cationic trans-[Co(en)2Cl2]+ complex ions through a simple cation-exchange process. The heterogenized trans-[Co(en)2Cl2]+-encapsulated InBTB MOF (trans-[Co(en)2Cl2]@InBTB) catalytic system maintained the activity of the captured trans-[Co(en)2Cl2]+ complex ion for hydrogen peroxide decomposition in aqueous solution under mild reaction conditions. The captured trans-[Co(en)2Cl2]+ complex also exhibited trans-cis isomerization to produce either cis-[Co(en)2Cl2]@InBTB or cis-[Co(en)2(H2O)Cl]@InBTB based on IR spectroscopic investigation. The trans-[Co(en)2Cl2]@InBTB catalytic system showed high recyclability for oxygen evolution from hydrogen peroxide. The catalytic ability of trans-[Co(en)2Cl2]@InBTB was maintained up to seven times of recycling.

N-doped porous carbons derived from Zn-porphyrin-MOF.

N-doped porous metal-organic framework (MOF)-derived carbons (MDCs) were directly synthesized from a new Zn-DpyDtolP-MOF (ZnDpyDtolP·1/2DMF, H2DpyDtolP = 5,15-di(4-pyridyl)-10,20-di(4-methylphenyl)porphyrin) containing a 3D hexagonal network through a self-templated carbonization method. KOH-activated MDC derivatives denoted as MDC-700-nKOH were also prepared with different weight ratios of KOH activator to MDC (MDC : KOH = 1 : n, where n = 1, 2). Compared to bare MDC, MDC-700-nKOH showed effective improvements of both gas sorption and electrochemical capacitive properties. More developed microporosity by KOH activation might induce great enhancement of high operating capacitive performances. The N-doped MDC-700-2KOH had high maximum gravimetric specific capacitance (555.6 F g-1) and specific energy (40.4 W h kg-1) at 0.1 A g-1 in 1 M H2SO4. Even at a high current density of 190 A g-1 in 6 M KOH, it exhibited high capacitive performance with a large specific power of 80 423 W kg-1. MDC-700-nKOH electrodes also showed good recycling properties of electrochemical capacitance up to 30 000 cycles.

Selection and characterization of a 7-mer peptide binding to divalent cations.

A 7-mer peptide (S-T-L-P-L-P-P) that bound to various divalent cations was selected from a phage display peptide library. Isothermal calorimetric analysis revealed that the peptide bound to Pb²âº, Cd²âº, Hg²âº, and Cu²âº. Through the use of CD studies, no secondary structural changes were observed for the peptide upon binding to divalent cations. Ala scanning mutant peptides bound to Hg²âº with a reduced affinity. However, no single substitution was shown to affect the overall affinity. We suggest that Pro residues chelate divalent cations, while the structure formed by the peptide is also important for the binding process.

catena-Poly[[bis-(dimethyl-ammonium) [cadmate(II)-bis-(µ-1,1':4',1''-terphenyl-3,3''-dicarboxyl-ato)]] dimethyl-formamide disolvate].

In the title compound, {(C(2)H(8)N)(2)[Cd(C(20)H(12)O(4))(2)]·2C(3)H(7)NO}(n), the Cd(II) ion lies on a twofold rotation axis and is in a distorted octa-hedral CdO(6) environment, defined by four O atoms of two µ(2)-coordinated 1,1':4',1''-terphenyl-3,3''-dicarboxyl-ate (DCT) ligands and two O atoms of two µ(1)-coordinated DCT ligands. Both types of DCT ligands act as bridging, forming a one-dimensional polymeric structure propagating parallel to [10].

Porous Carbon-Based Supercapacitors Directly Derived from Metal-Organic Frameworks.

Numerously different porous carbons have been prepared and used in a wide range of practical applications. Porous carbons are also ideal electrode materials for efficient energy storage devices due to their large surface areas, capacious pore spaces, and superior chemical stability compared to other porous materials. Not only the electrical double-layer capacitance (EDLC)-based charge storage but also the pseudocapacitance driven by various dopants in the carbon matrix plays a significant role in enhancing the electrochemical supercapacitive performance of porous carbons. Since the electrochemical capacitive activities are primarily based on EDLC and further enhanced by pseudocapacitance, high-surface carbons are desirable for these applications. The porosity of carbons plays a crucial role in enhancing the performance as well. We have recently witnessed that metal-organic frameworks (MOFs) could be very effective self-sacrificing templates, or precursors, for new high-surface carbons for supercapacitors, or ultracapacitors. Many MOFs can be self-sacrificing precursors for carbonaceous porous materials in a simple yet effective direct carbonization to produce porous carbons. The constituent metal ions can be either completely removed during the carbonization or transformed into valuable redox-active centers for additional faradaic reactions to enhance the electrochemical performance of carbon electrodes. Some heteroatoms of the bridging ligands and solvate molecules can be easily incorporated into carbon matrices to generate heteroatom-doped carbons with pseudocapacitive behavior and good surface wettability. We categorized these MOF-derived porous carbons into three main types: (i) pure and heteroatom-doped carbons, (ii) metallic nanoparticle-containing carbons, and (iii) carbon-based composites with other carbon-based materials or redox-active metal species. Based on these cases summarized in this review, new MOF-derived porous carbons with much enhanced capacitive performance and stability will be envisioned.

Gas sorption and supercapacitive properties of hierarchical porous graphitic carbons prepared from the hard-templating of mesoporous ZnO/Zn(OH)2 composite spheres.

Three-dimensional (3D) hierarchical porous carbon materials (PCMs) with graphitic carbon walls are facilely prepared through the hard-templating of acid-labile mesoporous ZnO/Zn(OH)2 spheres. Furfuryl alcohol or phloroglucinol is employed as a carbon precursor for two hierarchical porous carbon materials (PCM-F and PCM-P). The basic surfaces of ZnO/Zn(OH)2 are highly suited to the polymerization of the carbon precursors without extra catalysts. After carbonization followed by mild acid etching, hierarchical PCMs are obtained. These PCMs consist of interconnected turbostratic carbon wall structures. Gas sorption analysis indicates the surface areas of PCM-F and PCM-P are 1013 and 1075 m2 g-1, respectively. The corresponding pore volumes are very large, 3.39 and 3.01 cm3 g-1, respectively. The uptake abilities for carbon dioxide and hydrogen are investigated at 196 and 77 K, respectively. The PCM-P reveals higher uptake of H2 (1.19 wt%) and CO2 (282.0 cm3 g-1) than for PCM-F. In contrast, PCM-F shows a high gravimetric specific capacitance of 329.5 F g-1 based on galvanostatic charge/discharge curves at a current density of 0.1 A g-1. The PCM-F exhibits stable capacitance retention after 10,000 cycles at a current density of 5 A g-1.

Analysis of the effects of Cu-MOFs on fungal cell inactivation.

Three dimensional (3D) copper metal organic frameworks (Cu-MOFs) containing glutarates and bipyridyl ligands (bpa = 1,2-bis(4-pyridyl)ethane, bpe = 1,2-bis(4-pyridyl)ethylene, or bpp = 1,3-bis(4-pyridyl)propane) were synthesized by using previously reported hydrothermal reactions or a layering method. All three Cu-MOFs contained well-defined one dimensional (1D) channels with very similar pore shapes and different pore dimensions. The bulk purities of the Cu-MOFs were confirmed using powder X-ray diffraction (PXRD) and infrared spectroscopy (IR) spectra. When the three types of Cu-MOFs were applied to Candida albicans cells and Aspergillus niger spores, an average of about 50-80% inactivation was observed at the highest concentration of Cu-MOFs (2 mg mL-1). The efficiency of the fungal inactivation was not significantly different among the three different types (bpa, bpe, bpp). Treatment of the fungi using Cu-MOFs induced an apoptosis-like death and this was more severe in A. niger than C. albicans. This may be due to elevation of the intracellular level of reactive oxygen species (ROS) in A. niger. Generation of the reactive species in solution by Cu-MOFs was observed. However, there was a dramatic variation in the levels observed among the three types. Our results suggest that Cu-MOFs can produce antifungal effects and induce apoptosis-like death of the fungi, which was probably caused by the elevated level of intracellular reactive species.

Gated proton transport in aligned mesoporous silica films.

Modulated proton transport plays significant roles in biological processes such as ATP synthesis as well as in technologically important applications including, for example, hydrogen fuel cells. The state-of-the-art proton-exchange membrane is the sulphonated tetrafluoroethylene copolymer Nafion developed by DuPont in the late 1960s, with a high proton conductivity. However, actively switchable proton conduction, a functional mimic of the ion transport within a cell membrane, has yet to be realized. Herein, we report the electrostatic gating of proton transport within aligned mesoporous silica thin film. It is observed that surface-charge-mediated transport is dominant at low proton concentrations. We have further demonstrated that the proton conduction can be actively modulated by two-fourfold with a gate voltage as low as 1 V. Such artificial gatable ion transport media could have potential applications in nanofluidic chemical processors, biomolecular separation and electrochemical energy conversion.

Mesostructured material based on [Re6Te8(CN)6]4- cluster and Mn(2+): a rational synthesis of hexagonal nonoxidic mesoscale material.

A new nonoxidic mesostructured material with highly ordered hexagonal symmetry, [C(16)H(33)N(CH(3))(3)](3)Mn(0.5)[Re(6)Te(8)(CN)(6)], has been obtained through supramolecular assembly of [Re(6)Te(8)(CN)(6)](4-) clusters in the presence of a transition metal cation, Mn(2+), with cetyltrimethylammonium bromide as a liquid crystal template under hydrothermal conditions.

Antibacterial activities of Cu-MOFs containing glutarates and bipyridyl ligands.

Metal-organic frameworks (MOFs) can be utilized as antibacterial agents due to their effective antibacterial activities. Four three-dimensional (3D) Cu-MOFs formulated as [Cu2(Glu)2(µ-L)]·x(H2O) (Glu is glutarate, and L is bpy = 4,4'-bipyridine (1), bpa = 1,2-bis(4-pyridyl)ethane (2), bpe = 1,2-bis(4-pyridyl)ethylene (3), and bpp = 1,2-bis(4-pyridyl)propane (4)) were synthesized by hydrothermal reactions or modified literature methods. Their solid-state structures were slightly modified to increase their hydrolytic stabilities in aqueous solution. Despite the seemingly sufficient void spaces in all the solvent-free MOFs, only the thermally activated form of MOF 2 displayed selective gas uptake ability for CO2 over N2 and H2. The antibacterial activities of the four Cu-MOFs, 1, 2, 3, and 4, were investigated by determining their minimal bactericidal concentration (MBC) values against five strains of bacteria, including E. coli, S. aureus, K. pneumonia, P. aeruginosa, and MRSA, which can be easily met in our daily surrounding environments. Although these Cu-MOFs were found to be structurally very stable in aqueous medium during antibacterial activity tests, they exhibited excellent antibacterial activities against all five kinds of bacteria, including Gram-positive bacteria (S. aureus and MRSA) and Gram-negative bacteria (E. coli, K. pneumonia, and P. aeruginosa), with very low MBCs. The robust 3D frameworks with surface active metal sites rather than the small amount of leached CuII ions may participate more strongly in inactivating various kinds of bacteria and reduce potential cytotoxicity mainly caused by leached metal ions.

Cobalt(II)-coordination polymers containing glutarates and bipyridyl ligands and their antifungal potential.

Three new CoII-coordination polymers (Co-CPs) containing glutarates and bipyridyl ligands, formulated as [Co2(Glu)2(µ-bpa)2]·(H2O)4 (1), [Co4(Glu)4(µ-bpp)2] (2), and [Co2(Glu)2(µ-bpe)2]·(H2O)0.5 (3), were prepared, and their structures were determined by X-ray crystallography. Glutarates bridge CoII ions to form 2D sheets, and the sheets are connected either by bpa or by bpp ligands to form 3D networks 1 and 2, respectively. Both frameworks 1 and 2 are two-fold interpenetrated, and there is no significant void volume in either network. Four glutarates bridge two CoII ions to form chains, and these chains are connected by bpe ligands to form the 2D sheet 3. The antifungal properties of these new Co-CPs were tested against two model fungal pathogens, Candida albicans and Aspergillus niger. Under the maximum concentration of Co-CPs, 2.0 mg mL-1, the inhibition rates of Co-CPs against A. niger were much lower (44-62%) than those (90-99.98%) observed in C. albicans. The results indicate that 1-3 can inactivate C. albicans cells more efficiently than A. niger spores in the same treatment time, and the greater inactivation of C. albicans can be explained by dramatic changes in the morphology of C. albicans cells. We also found that Co-CPs could generate the reactive species NO and H2O2, and these species might play a role in inactivating fungal cells. Additionally, degradation tests confirmed that the leaching of CoII ions from Co-CPs was not significant. The small amount of leached CoII ions and the robust Co-CPs themselves as well as the reactive species generated by Co-CPs can actively participate in fungal inactivation.

trans-Carbon-yl[dihydro-bis(1,2,4-triazol-1-yl-κN)borato]hydridobis(triphenyl-phosphine-κP)ruthenium(II) acetonitrile solvate.

In the crystal structure of the title compound, [Ru(C(4)H(6)BN(6))H(C(18)H(15)P)(2)(CO)]·C(2)H(3)N, discrete mononuclear complexes are found in which the Ru atom is coordinated by two triphenyl-phosphine (PPh(3)) ligands, one dihydro-bis(1,2,4-triazol-1-yl)borate ligand, one carbonyl ligand and one hydride atom within slightly distorted octa-hedra. The two P atoms of the PPh(3) ligands are trans positioned and the two N atoms of the chelating dihydro-bis(1,2,4-triazol-1-yl)borate ligand occupy cis positions.

[1,1'-Bis(diphenyl-phosphino)ferrocene]carbon-yl[dihydro-bis(pyrazol-1-yl)borato]hydridoruthenium(II) acetone solvate.

In the title compound, [FeRu(C(17)H(14)P)(2)(C(6)H(8)BN(4))H(CO)]·C(3)H(6)O, the Ru(II) ion is coordinated in a distorted octa-hedral environment involving a hydride ligand, a carbonyl ligand and two bidentate ligands. Of the two bidentate ligands, the bulky 1,1'-bis-(diphenyl-phosphino)ferrocene (dppf) ligand chelates with a larger bite angle of 101.90 (2)°, whereas the bite angle of the [H(2)Bpz(2)](-) ligand (pz = pyrazol-yl) is 85.67 (7)°. The latter ligand creates an RuN(4)B six-membered ring with a boat conformation, which puckers towards the site of the small hydride ligand. The hydride ligand is cis with respect to the carbonyl ligand and trans to one of the P atoms of the dppf ligand. In the crystal structure, there are weak inter-molecular C-H⋯O hydrogen bonds between complex mol-ecules and acetone solvent mol-ecules.