Configurationally Nonselective Aquation of a Mononuclear Ru(II) Chloro Complex to Aquo Complex Isomers with Distinctive Aspects in Photoisomerization, Redox, and Catalytic Water Oxidation.

distal-[Ru(EtOtpy)(pynp)Cl]+ (d-EtO1Cl) (EtOtpy = 4'-ethoxy-2,2':6',2″-terpyridine, pynp = 2-(2-pyridyl)-1,8-naphthyridine), and distal/proximal-[Ru(EtOtpy)(pynp)OH2]2+ (d/p-EtO1H2O) complexes were newly synthesized to investigate the synergistic influence of the geometric configuration coupled with substituent introduction of an ethoxy (EtO) group on the physicochemical properties and reactions of the Ru(II) complexes. Configurationally nonselective aquation of d-EtO1Cl was uniquely observed to form d/p-EtO1H2O isomers in water, in contrast to configurationally selective aquation of distal-[Ru(tpy)(pynp)Cl]+ (d-1Cl, tpy = 2,2':6',2″-terpyridine) without the EtO group [Yamazaki, H. . J. Am. Chem. Soc. 2011, 133, 8846-8849].The kinetic profiles of the aquation reactions of d-EtO1Cl were well analyzed using a sequential reversible reaction model assuming the reversible interconversion between d/p-EtO1H2O isomers via d-EtO1Cl. The observed equilibrium constant (Kiso) of isomerization between p/d-EtO1H2O was calculated from the kinetic analysis as Kiso = 0.45, which is consistent with the final concentration ratio (1:0.43) of p/d-EtO1H2O generated in the aquation reaction of d-EtO1Cl. The irreversible photoisomerization from d-EtO1H2O to p-EtO1H2O was observed in water with an internal quantum yield (Φ) of 0.44% at 520 nm. Electrochemical measurements showed that d-EtO1H2O undergoes a 2-step oxidation reaction of 1H+-coupled 1e- processes of RuII-OH2/RuIII-OH and RuIII-OH/RuIV═O at pH 1.3-9.7, whereas p-EtO1H2O undergoes a 1-step oxidation reaction of a 2H+-coupled 2e- process of RuII-OH2/RuIV═O in the pH range of 1.8-11.5. Any redox potential of d/p-EtO1H2O isomers was decreased by the electro-donating EtO substitution, compared with distal/proximal-[Ru(tpy)(pynp)OH2]2+ (d/p-1H2O). The turnover frequency (kO2 = 1.7 × 10-2 s-1) of d-EtO1H2O for water oxidation catalysis is higher than that (3.5 × 10-4 s-1) of p-EtO1H2O by a factor of 48.6. The kO2 value (1.7 × 10-2 s-1) for d-EtO1H2O is 4.5-fold higher than those of d-1H2O (3.8 × 10-3 s-1). The higher kO2 value of d-EtO1H2O compared with d-1H2O could be explained by the fast oxidation rate from RuIV═O to RuV═O involved in the rate-determining step due to the electron-donating EtO group.

Temperature-Controlled Transformation of WO3 Nanowires into Active Facets-Exposed Hexagonal Prisms toward Efficient Visible-Light-Driven Water Oxidation.

A unique transformation of WO3 nanowires (NW-WO3) into hexagonal prisms (HP-WO3) was demonstrated by tuning the temperature of the (N2H4)WO3 precursor suspension prepared from tungstic acid and hydrazine as a structure-directing agent. The precursor preparation at 20 °C followed by calcination at 550 °C produced NW-WO3 nanocrystals (ca. <100 nm width, 3-5 µm length) with anisotropic growth of monoclinic WO3 crystals to (002) and (200) planes and a polycrystalline character with randomly oriented crystallites in the lateral face of nanowires. The precursor preparation at 45 °C followed by calcination at 550 °C produced HP-WO3 nanocrystals (ca. 500-1000 nm diameter) with preferentially exposed (002) and (020) facets on the top-flat and side-rectangle surfaces, respectively, of hexagonal prismatic WO3 nanocrystals with a single-crystalline character. The HP-WO3 electrode exhibited the superior photoelectrochemical (PEC) performance for visible-light-driven water oxidation to that for the NW-WO3 electrode; the incident photon-to-current conversion efficiency (IPCE) of 47% at 420 nm and 1.23 V vs RHE for HP-WO3 was 3.1-fold higher than 15% for the NW-WO3 electrode. PEC impedance data revealed that the bulk electron transport through the NW-WO3 layer with the unidirectional nanowire structure is more efficient than that through the HP-WO3 layer with the hexagonal prismatic structure. However, the water oxidation reaction at the surface for the HP-WO3 electrode is more efficient than the NW-WO3 electrode, contributing significantly to the superior PEC water oxidation performance observed for the HP-WO3 electrode. The efficient water oxidation reaction at the surface for the HP-WO3 electrode was explained by the high surface fraction of the active (002) facet with fewer grain boundaries and defects on the surface of HP-WO3 to suppress the electron-hole recombination at the surface.

Distinctive Aspects in Aquation, Proton-Coupled Redox, and Photoisomerization Reactions between Geometric Isomers of Mononuclear Ruthenium Complexes with a Large-π-Conjugated Tetradentate Ligand.

Geometric isomers of mononuclear ruthenium(II) complexes, distal-/proximal-[Ru(tpy)(dpda)Cl]+ (d-/p-RuCl, tpy = 2,2':6',2″-terpyridine, dpda = 2,7-bis(2-pyridyl)-1,8-diazaanthracene), were newly synthesized to comprehensively investigate the geometric and electronic structures and distinctive aspects in various reactions between isomers. The ultraviolet (UV)-visible absorption spectra of d-/p-RuCl isomers show intense bands for metal-to-ligand charge transfer (MLCT) at close wavelengths of 576 and 573 nm, respectively. However, time-dependent density functional theory (TD-DFT) calculations suggest that the MLCT transition of d-RuCl involves mainly single transitions to the π* orbital of the dpda ligand in contrast to mixing of the π* orbitals of the dpda and tpy ligands for p-RuCl. The aquation reaction (1.5 × 10-3 s-1) of p-RuCl to yield proximal-[Ru(tpy)(dpda)(OH2)]2+ (p-RuH2O) is faster than that (5.3 × 10-6 s-1) of d-RuCl in D2O/CD3OD (4:1 v/v) by three orders of magnitude, which resulted from the longer Ru-Cl bond by 0.017 Å and the distorted angle (100.2(3)°) of Cl-Ru-N (a nitrogen of dpda, being on a tpy plane) due to the steric repulsion between Cl and dpda for p-RuCl. Electrochemical measurements showed that d-RuH2O undergoes a 2-step oxidation reaction of 1H+-coupled 1e- processes of RuII-OH2/RuIII-OH and RuIII-OH/RuIV═O at pH 1-9, whereas p-RuH2O undergoes a 1-step oxidation reaction of a 2H+-coupled 2e- process of RuII-OH2/RuIV═O in the pH range of pH 1-10. The irreversible photoisomerization from d-RuH2O to p-RuH2O was observed in aqueous solution with an internal quantum yield (Φ) of 5.4 × 10-3% at 520 nm, which is lower compared with Φ = 1.1-2.1% of mononuclear Ru(II) aquo complexes with similar bidentate ligands instead of dpda by three orders of magnitude. This is possibly ascribed to the faster nonradiative decay rate from the excited 3MLCT state to the ground state for d-RuH2O due to the lower π* level of dpda ligands according to the energy-gap law: the rate decreases exponentially with the increasing energy gap.

Highly Efficient and Durable Electrocatalysis by a Molecular Catalyst with Long Alkoxyl Chains Immobilized on a Carbon Electrode for Water Oxidation.

A dinuclear Ru complex, proximal,proximal-[Ru2L(C8Otpy)2(OH)(OH2)]3+ (C8Otpy = 4'-octyloxy-2,2'; 6',2″-terpyridine) (1) with long alkoxyl chains, was synthesized to be immobilized on a carbon paper (CP) electrode via hydrophobic interactions between the long alkoxyl chains and the CP surface. The 1/CP electrode demonstrated efficient electrocatalytic water oxidation with a low overpotential (ηonset) of 0.26 V (based on the onset potential for water oxidation) in an aqueous medium at pH 7.0, which is compared advantageously with those of hitherto-reported molecular anodes for water oxidation. The active species of RuIIIRuIII(µ-OO) with a µ-OO bridge was involved in water oxidation at 0.95 V versus Ag/AgCl. As the applied potential increased to 1.40 V, water oxidation was promoted by participation of the more active species of RuIIIRuIV(µ-OO), and very durable electrocatalysis was gained for more than 35 h without elution of 1 into the electrolyte solution. The introduced long alkoxyl chains act as a dual role of the linker of 1 on the CP surface and decrease the η value. Theoretical investigation provides insights into the O-O bond formation mechanism and the activity difference between RuIIIRuIII(µ-OO) and RuIIIRuIV(µ-OO) for electrocatalytic water oxidation.

in vivo Evaluation of Immunomodulatory Activity of Lipopolysaccharide Zinc Oxide Nanoparticles (LPS-ZnNPS).

Klebsiella pneumoniae causes a wide variety of infectious diseases. Lipopolysaccharide (LPS) is a large heat-stable polymer that is gram-negative bacteria's major outer membrane component, accounting for roughly 75% of the surface area and 5-10% of the total dry weight. Therefore the current in vivo study was carried out to investigate the immunomodulatory effect of purified lipopolysaccharide produced from local clinical Klebsiella pneumoniae isolates compared with ZnO-NPs and LPS-ZnO NPs. To do the experimental evaluations 35, Balb/c mouse was injected intramuscularly (i.m.) with different concentrations of the purified LPS, ZnoNPs and LPS-ZnoNPs for 12 days and immunized with 10% SRBCs (i.p) on day 4 and 8 of the schedule, while K. pneumoniae suspension and normal saline for positive and negative control groups. Focus on estimating body weight before and after treatment, Arthus and delayed-type hypersensitivity, and detecting serum level of cytokines (TLR-2, IL1Beta, IL4, and IL10) using sandwich ELISA. The data showed the highest value before and after treatment with LPS-ZnO NPs recorded in 2µg/mouse was 27. 92±1.48 and 31.50±0.4, respectively. In Arthurs reaction and Delayed type hypersensitivity, the highest results showed in the positive control group injected with K. pneumoniae 4.08±0.17 and 4.86±80.02, respectively. The results of TLR-2 showed the highest value in the positive control group, 242.17±3.98 pg/ml, followed by Group LPS at 135.51.58 pg/ml. The results of Interleukin-1Beta showed the highest value in the positive control group, 254.88±3.51 pg/ml, followed by Group LPS 174.3± 1.46 pg/ml. The concentration of IL-4 in serum of treated albino mice showed the highest value in the positive control group, 136.2±1.12 pg/ml, followed by Group LPS 86.12±1.49 pg/ml. While the highest value of IL-10 was recorded in the positive control group, 98.58± 4.09 pg/ml, followed by Group LPS- ZnoNP in concentration 4µg/ mouse was 86.018±0.69 pg/ml. The results of the statistical analysis showed a significant difference (P≤0.05) between LPS, ZnoNPs, and LPs-ZnoNPs treated groups and control groups (positive & negative). In the present study, we can conclude that LPS-ZnO NPs had a positive immunomodulatory effect on immune response in immunized mice. As shown in the results of the level of IL-1 beta, IL-4, IL-10, and TLRs-2, Abs titer, and Arthus and DTH reactions.

Mechanism of H+ dissociation-induced O-O bond formation via intramolecular coupling of vicinal hydroxo ligands on low-valent Ru(III) centers.

The understanding of O-O bond formation is of great importance for revealing the mechanism of water oxidation in photosynthesis and for developing efficient catalysts for water oxidation in artificial photosynthesis. The chemical oxidation of the RuII2(OH)(OH2) core with the vicinal OH and OH2 ligands was spectroscopically and theoretically investigated to provide a mechanistic insight into the O-O bond formation in the core. We demonstrate O-O bond formation at the low-valent RuIII2(OH) core with the vicinal OH ligands to form the RuII2(µ-OOH) core with a µ-OOH bridge. The O-O bond formation is induced by deprotonation of one of the OH ligands of RuIII2(OH)2 via intramolecular coupling of the OH and deprotonated O- ligands, conjugated with two-electron transfer from two RuIII centers to their ligands. The intersystem crossing between singlet and triple states of RuII2(µ-OOH) is easily switched by exchange of H+ between the µ-OOH bridge and the auxiliary backbone ligand.

Prognostic significance of microRNA 17-92 cluster expression in Egyptian chronic lymphocytic leukemia patients.

BACKGROUND: Abnormal expression patterns of microRNAs (miRs) play an important role in the development and progression of malignancy. Identification of the clinical significance and prognostic value of these small molecules in chronic lymphocytic leukemia (CLL); a disease of heterogeneous biological landscape and clinical course, has always been of tremendous translational value. AIM: To evaluate the prognostic value of microRNA17-92 cluster members in Egyptian CLL patients. METHODS: The expression levels of miR17-92 cluster members were evaluated by qRT-PCR, including miR17, miR18a, miR19a, miR19b-1, miR20a, and miR92a-1. Other investigations included serum LDH, serum ß2 microglobulin (ß2M), CD38 and ZAP70 expression by flow cytometry, fluorescence in situ hybridization (FISH) for 17p deletion, and imaging studies (computerized tomography (CT) scans of neck, chest, abdomen, and pelvis or PET-CT scans). RESULTS: Overexpression of all members of the miRNA17-92 cluster was detected in CLL patients compared to controls (p = < 0.001 for all miRs while p = 0.01 for miR19b-1). A significant positive correlation between Hb and miR17 and a significant negative correlation between Hb and miR19b-1 were observed (p = 0.041, 0.017 respectively). A statistically significant positive correlation between miR19b-1 expression and each of the WBCs and absolute lymphocytic count (ALC) was detected (p = 0.023, 0.022 respectively). Moreover, a statistically significant relation between miR19b-1 expression and advanced Binet stages was also found (p = 0.05). Regarding miR18a, a statistically significant positive correlation with LDH level was found (p = 0.003). We also found a significant positive correlation between miR92a-1 and ß2M level (p = 0.005), as well as a significant relation between miR17 and negative CD38 expression (p = 0.034). However, no significant relationships between any of studied miRNA expression levels and 17p deletion or response to treatment were observed. Patients who expressed miR19b-1 were significantly indicated to start therapy at diagnosis (p = 0.05). The overall survival of CLL patients included in our study was 90.2% after 1 year from the time of diagnosis. Patients with high expression of miR19a had better OS than those with low expression (p = 0.04). CONCLUSIONS: Overexpression of all members of the miR17-92 cluster was detected in Egyptian CLL patients. MiR18a, miR19b-1, and miR92a-1 also have an adverse prognostic value while miR17 can be considered a good prognostic marker. High expression of miR19a is associated with better OS.

Facile Fabrication of a Highly Crystalline and Well-Interconnected Hematite Nanoparticle Photoanode for Efficient Visible-Light-Driven Water Oxidation.

Facile and scalable fabrication of α-Fe2O3 photoanodes using a precursor solution containing FeIII ions and 1-ethylimidazole (EIm) in methanol was demonstrated to afford a rigidly adhered α-Fe2O3 film with a controllable thickness on a fluorine-doped tin oxide (FTO) substrate. EIm ligation to FeIII ions in the precursor solution brought about high crystallinity of three-dimensionally well-interconnected nanoparticles of α-Fe2O3 upon sintering. This is responsible for the 13.6 times higher photocurrent density (at 1.23 V vs reference hydrogen electrode (RHE)) for photoelectrochemical (PEC) water oxidation on the α-Fe2O3 (w-α-Fe2O3) photoanode prepared with EIm compared with that (w/o-α-Fe2O3) prepared without EIm. The w-α-Fe2O3 photoanode provided the highest charge separation efficiency (ηsep) value of 27% among the state-of-the-art pristine α-Fe2O3 photoanodes, providing incident photon-to-current conversion efficiency (IPCE) of 13% at 420 nm and 1.23 V vs RHE. The superior ηsep for the w-α-Fe2O3 photoanode is attributed to the decreased recombination of the photogenerated charge carriers at the grain boundary between nanoparticles, in addition to the higher number of the catalytically active sites and the efficient bulk charge transport in the film, compared with w/o-α-Fe2O3.

Intestinal protozoan infections among Egyptian neutropenic patients with acute leukemia.

Several enteric protozoan species are linked to diarrhea in humans, with some causing debilitating illnesses, essentially in immunocompromised and neutropenic patients as in acute leukemias. The aim of this study was to detect intestinal protozoa in Egyptian neutropenic patients with acute leukemia. The study comprised two groups; 40 newly diagnosed neutropenic acute leukemia patients and 30 controls. Stool samples were collected from all participants and subjected to routine microscopic examination, special staining and detection of copro-antigen using rapid diagnostic test (RDT) RIDA®QUICK Entamoeba/ Giardia/ Cryptosporidium Combi. Cases were tested post-chemotherapy at the nadir of neutropenia (absolute neutrophil count ANC<= 0.5x109/L) and 19 cases were also tested initially prior to chemotherapy. Of examined patients, 15/40 (37%) were positive for Blastocystis hominis by wet mount, 10/40 (25%) had microsporidia using modified trichrome stain and only 2 cases (5%) of Cryptosporidium spp. by Ziehl-Neelsen stain. By RDT, 8/40 cases (20%) were positive compared to entirely negative controls. The positive cases included 4 patients with G. intestinalis 2 with Entamoeba and 2 with Cryptosporidium.19/40 cases were tested both pre- and post-chemotherapy. microsporidian spp. was diagnosed in 6/19 cases at the nadir of neutropenia compared to none of the cases pre-chemotherapy and the difference was statistically significant (p= 0.031*). Intestinal protozoa in acute leukemia patients post-chemotherapy are common especially B. hominis. Furthermore, RDT might be helpful for diagnosing intestinal protozoa in acute leukemia. Attention is highly required as intestinal protozoa infection can emerge after chemotherapy such as microsporidia.

Intestinal protozoan infections among Egyptian neutropenic patients with acute leukemia

@#Several enteric protozoan species are linked to diarrhea in humans, with some causing debilitating illnesses, essentially in immunocompromised and neutropenic patients as in acute leukemias. The aim of this study was to detect intestinal protozoa in Egyptian neutropenic patients with acute leukemia. The study comprised two groups; 40 newly diagnosed neutropenic acute leukemia patients and 30 controls. Stool samples were collected from all participants and subjected to routine microscopic examination, special staining and detection of copro-antigen using rapid diagnostic test (RDT) RIDA®QUICK Entamoeba/ Giardia/ Cryptosporidium Combi. Cases were tested post-chemotherapy at the nadir of neutropenia (absolute neutrophil count ANC< 0.5x109/L) and 19 cases were also tested initially prior to chemotherapy. Of examined patients, 15/40 (37%) were positive for Blastocystis hominis by wet mount, 10/40 (25%) had microsporidia using modified trichrome stain and only 2 cases (5%) of Cryptosporidium spp. by Ziehl-Neelsen stain. By RDT, 8/40 cases (20%) were positive compared to entirely negative controls. The positive cases included 4 patients with G. intestinalis 2 with Entamoeba and 2 with Cryptosporidium.19/40 cases were tested both pre- and post-chemotherapy. microsporidian spp. was diagnosed in 6/19 cases at the nadir of neutropenia compared to none of the cases pre-chemotherapy and the difference was statistically significant (p= 0.031*). Intestinal protozoa in acute leukemia patients post-chemotherapy are common especially B. hominis. Furthermore, RDT might be helpful for diagnosing intestinal protozoa in acute leukemia. Attention is highly required as intestinal protozoa infection can emerge after chemotherapy such as microsporidia.

Multi-potential-step chronocoulospectrometry for electrocatalytic water oxidation by a mononuclear ruthenium aquo complex immobilized on a mesoporous ITO electrode.

A new mononuclear Ru aquo complex [Ru(C8Otpy)(H2dcbpy)(OH2)]2+ with 4,4'-dicarboxy-2,2'-bipyridine (H2dcbpy) and 4'-octyloxy-2,2':6',2''-terpyridine (C8Otpy) ligands was synthesized to investigate electrocatalytic water oxidation by the complex immobilized on a mesoporous indium-doped tin oxide (meso-ITO) electrode using a multi-potential-step chronocoulospectrometric (MPSCCS) technique. UV-visible absorption spectroscopic data indicated that [Ru(C8Otpy)(dcbpy)(OH2)] (RuOH2) is deprotonated to [Ru(C8Otpy)(dcbpy)(OH)]- (RuOH) on the meso-ITO surface even at pH 5.9 of the electrolyte solution. The cyclic voltammogram (CV) of the RuOH/meso-ITO electrode showed a pH-independent redox response at E1/2 = 0.80 V vs. Ag/AgCl in the pH range of 5-12, being assigned to a non-proton-coupled 1e- redox process of RuIIOH/RuIIIOH. The MPSCCS measurement of the RuOH/meso-ITO electrode between 0.2 and 1.5 V vs. Ag/AgCl showed that RuIV species (tentatively RuIVO) exist in a steady state of the electrocatalysis in the initial stage. This suggests that the electrochemical oxidation from RuIVO to RuVO could compete with the water nucleophilic attack for O-O bond formation involved in the rate-determining step under the employed conditions. The possibility that the water nucleophilic attack on RuIVO could also compete with the electrochemical oxidation of RuIVO to RuVO was suggested by the electrocatalytic water oxidation at a low applied potential of 1.4 V prior to the formation potential of RuVO. The MPSCCS measurement at 1.4 V for 1 h showed that RuOH is gradually transformed into an alternative catalyst (most likely RuOx nanoparticles) on the electrode. The MPSCCS technique is promising to reveal the redox reactions and catalytic aspects of molecular catalysts immobilized on an electrode for water oxidation.

Critical Hammett Electron-Donating Ability of Substituent Groups for Efficient Water Oxidation Catalysis by Mononuclear Ruthenium Aquo Complexes.

[Ru(Rtpy)(bpy)(H2O)]2+ (1R; bpy = 2,2'-bipyridine, and Rtpy = 2,2':6',2″-terpyridine derivatives) complexes with a variety of 4'-substituent groups on Rtpy were synthesized and characterized to reveal the effects of substituents on their structures, physicochemical properties, and catalytic activities for water oxidation. The geometric structures of 1R are not considerably influenced by the electron-donating ability of the 4'-substituent groups on Rtpy. Similar multistep proton-coupled electron transfer reactions were observed for 1R, and the redox potentials for each oxidation step tended to decrease with an increase in the electron-donating ability of the substituent, which is explained by the increased electron density on the Ru center by electron-donating groups, stabilizing the positive charge that builds up upon oxidation. This is consistent with the red-shift of the absorption bands around 480 nm assigned to the metal-to-ligand charge transfer transition for 1R due to the increased d orbital energy level of the Ru center. The turnover frequency (kO2) of 1R for water oxidation catalysis, however, depended greatly on the Rtpy ligands, varying from 0.05 × 10-2 to 44 × 10-2 s-1 (as the highest kO2 was observed for R = ethoxy) by a factor of 880. A critical electron-donating ability of the 4'-substituent groups with a narrow range of Hammett constants (σp = -0.27 to -0.24) found for the highest kO2 values is valuable for understanding the great difficulty in the search for efficient water oxidation catalysts. On another front, the kO2 values increased with a decrease in the redox potentials of RuIV═O/RuV═O for 1R, indicating that the potential of formation of RuV═O species for 1R is crucial for water oxidation catalysis under the employed conditions.

Recent Advances in the Development of Molecular Catalyst-Based Anodes for Water Oxidation toward Artificial Photosynthesis.

Catalytic water oxidation represents a bottleneck for developing artificial photosynthetic systems that store solar energy as renewable fuels. A variety of molecular water oxidation catalysts (WOCs) have been reported over the last two decades. In view of their applications in artificial photosynthesis devices, it is essential to immobilize molecular catalysts onto the surfaces of conducting/semiconducting supports for fabricating efficient and stable water oxidation anodes/photoanodes. Molecular WOC-based anodes are essential for developing photovoltaic artificial photosynthesis devices and, moreover, the performance of molecular WOC on anodes will provide important insight into designing extended molecular WOC-based photoanodes for photoelectrochemical (PEC) water oxidation. This Review concerns recent progress in the development of molecular WOC-based anodes over the last two decades and looks at the prospects for using such anodes in artificial photosynthesis.

Correction to: Comparative study using fractional carbon dioxide laser versus glycolic acid peel in treatment of pseudo-acanthosis nigricans.

Unfortunately, there are two mistakes in the published article. The first mistake is found in the Results section, Clinical improvement subsection. The last sentence "There was no statistical difference between both sides (P=0.008)." should be corrected to "There was statistical difference between both sides (P=0.008)."

Correction to: Comparative study using fractional carbon dioxide laser versus glycolic acid peel in treatment of pseudo-acanthosis nigricans.

The author found small mistakes in scientific content of article. Editor-in-Chief confirmed that mistakes do not change or invalidate conclusions of article.

Comparative study using fractional carbon dioxide laser versus glycolic acid peel in treatment of pseudo-acanthosis nigricans.

Pseudo-acanthosis nigricans is a common dermatological disorder that is usually difficult to treat secondary to maceration of the skin from excessive sweating, obesity, or associated with endocrine disorders. Fractional photothermolysis and chemical peeling have been reported to improve the condition. To determine whether fractional CO2 laser resurfacing or glycolic acid peel is more effective and safe option for therapy. Twenty Egyptian patients were included in the study where each patient was subjected to three sessions of both fractional CO2 on the right side of the neck and glycolic acid peel 70% on the left side of the neck. All patients were evaluated by a scoring system Acanthosis Nigricans Area and Severity Index (ANASI) score and three blinded dermatologists before and after treatment. Clinical improvement on the side treated by glycolic acid peel showed 43% improvement while the side treated by fractional CO2 showed 19% improvement. Glycolic acid peel shows superior results to fractional CO2 due to accelerated induced exfoliation, yet still fractional CO2 results are promising due to a presumably long-term improvement of skin texture.

Efficient Solar-Assisted O2 Reduction Using a Cofacial Iron Porphyrin Dimer Catalyst Integrated into a p-CuBi2 O4 Photocathode.

A cofacial iron porphyrin heterodimer, Fe2 TPFPP-TMP showed high electrocatalytic activity, selectivity, and stability for O2 reduction to H2 O both in homogeneous non-aqueous and heterogeneous neutral aqueous solutions. When it is integrated to FTO/p-CuBi2 O4 (FTO=fluorine doped tin oxide) photocathode prepared by a simple novel method, a remarkable efficient solar-assisted O2 reduction is achieved in neutral potassium phosphate (KPi) or basic NaOH solutions saturated with O2 .

Bio-inspired cofacial Fe porphyrin dimers for efficient electrocatalytic CO2 to CO conversion: Overpotential tuning by substituents at the porphyrin rings.

Efficient reduction of CO2 into useful carbon resources particularly CO is an essential reaction for developing alternate sources of fuels and for reducing the greenhouse effect of CO2. The binuclear Ni, Fe-containing carbon monoxide dehydrogenase (CODHs) efficiently catalyzes the reduction of CO2 to CO. The location of Ni and Fe at proper positions allows their cooperation for CO2 to CO conversion through a push-pull mechanism. Bio-inspired from CODHs, we used several cofacial porphyrin dimers with different substituents as suitable ligands for holding two Fe ions with suitable Fe-Fe separation distance to efficiently and selectively promote CO2 to CO conversion with high turnover frequencies, TOFs. The substituents on the porphyrin rings greatly affect the catalysis process. By introducing electron-withdrawing/-donating groups, e.g. electron-withdrawing perfluorophenyl, at all meso positions of the porphyrin rings, the catalysis overpotential, η was minimized by ≈0.3 V compared to that obtained by introducing electron-donating mesityl groups. The Fe porphyrin dimers among reported catalysts are the most efficient ones for CO2 to CO conversion. Control experiments indicate that the high performance of the current CO2 to CO conversion catalysts is due to the presence of binuclear Fe centers at suitable Fe-Fe separation distance.

Efficient electrocatalytic CO2 reduction with a molecular cofacial iron porphyrin dimer.

A cofacial iron tetraphenyl porphyrin dimer, , bio-inspired by the Ni-Fe containing metalloenzyme, carbon monoxide dehydrogenase (CODH), efficiently and selectively catalyses the electrochemical reduction of CO2 to CO in DMF/10% H2O solution at the electro-generated Fe(0)(por) species with high Faradic efficiency (95%) and TOF (4300 s(-1)) at a moderate overpotential, η = 0.66 V.

Investigating the informed consent process, therapeutic misconception and motivations of Egyptian research participants: a qualitative pilot study.

Few studies have explored the informed consent process among research participants in developing countries. This study aimed to evaluate the informed consent process, therapeutic misconception and motivation for participation among Egyptians participating in clinical trials. In a cross-sectional qualitative pilot study 103 participants in 10 clinical trials responded to a questionnaire. Over 90% agreed they had time to ask questions and received adequate information about the risks prior to consenting. All participants thought the research and the drug would improve their condition; only 46.1% were aware of receiving a non-approved experimental drug and 21.3% of being randomized. Reasons for participation included: better treatment (100%), to benefit society & advance science (85.4%), to receive free drugs (42.6%) and medical care (43.6%), to get hospitalized (15.8%) and to receive money or gifts (4.9%). Investigators need to emphasize the distinction between research and clinical care to address the high rate of therapeutic misconception.