ICAR: endoscopic skull‐base surgery

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Synthesis, characterization and photophysical properties of [OsO2(mes)2(NC)Ru(bpy)2(CN)]

A novel heterometallic complex comprising of a d2 OsO2(mes)2 and a d6 Ru(bpy)2(CN)2 fragment is prepared and characterized by X-ray analysis; its photophysical properties are measured.link_to_subscribed_fulltex

Highly luminescent neutral cis-dicyano osmium(II) complexes

Two highly luminescent neutral cis-dicyanoosmium(II) complexes are prepared by photoinduced oxygen atom transfer reactions of trans-[OsO2(CN)2(dpphen)] with PPh3 and Me2SO; their MLCT excited states are emissive with long lifetimes (0.20-1.99 μs) and high quantum yields [(40-1.8) ×10-2] and the emission maxima show pronounced solvatochromism.link_to_subscribed_fulltex

Photocatalytic and aerobic oxidation of saturated alkanes by a neutral luminescent trans-dioxoosmium(vi) complex [OsO2(CN)2(dpphen)]

A neutral trans-dioxoosmium(vi) complex [OsO2(CN)2(dp-phen)] (dpphen = 4,7-diphenyl-1,10-phenanthroline) is prepared and characterized by X-ray crystal analysis; the excited state is long-lived, emissive and oxidizing [E°(OsVI-V) = 2.15 V vs. NHE; lifetime = 0.95 μs; quantum yield = 5 × 10-4; λem(max.) = 650 nm]; under UV-VIS irradiation and in the presence of dioxygen, cyclohexane is oxidized to cyclohexanol and cyclohexanone with a turnover number of 16; secondary C-H bonds of propane and primary C-H bonds of n-hexane are also oxidized.link_to_subscribed_fulltex

Reversible proton-coupled ReVII-ReVI and ReVI-ReV couples and crystal structure of [(RevO2(OH2)(Me3tacn)]BPh4 (Me3tacn=1,4,7-trimethyl-1,4,7-triazacyclononane)

The electrochemistry of [ReVIIO3(Me3tacn)]PF6 (Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) in aqueous solution has been studied. At pH 1 it shows two quasi-reversible couples I at 20.14 and II at 20.36 V vs. saturated calomel electrode. Constant-potential coulometry at 20.50 V shows that the total number of electrons transferred for these two couples is two. The Pourbaix diagram over the range pH 0.9–12.2 shows that E2¯ 1 of couple I shifts cathodically by 60 mV per pH unit. For couple II there are two straight-line segments with slopes of 2118 mV (0.9 4.1) per pH unit. The complex [ReVO2(OH2)(Me3tacn)]BPh4 was prepared and structurally characterized by X-ray crystal analysis: monoclinic, space group P21/n (no. 14), a = 10.387(9), b = 21.176(4), c = 15.452(2) Å, b = 91.38(63)8, Z = 4. The Re]OH2 distance is 2.10(2) Å and the Re]] O distances are 1.78(1) and 1.82(1) Å. The two oxo groups are cis to each other with an angle of 106.7(5)8

Rhenium(VII) and -(V) imido and oxo complexes containing 1,4,7-triazacyclononane: Synthesis, electrochemistry and crystal structures

A new class of cationic rhenium(VII) imido and oxo complexes wilh the macrocyclic ligand 1,4,7-triazacyclononane (L) was prepared. Depending on the reaction conditions, [(L - H)Re(N tBu)2(OSiMe3)]+ (1) [(L-H) denotes deprotonation at N], [LRe(N tBu)2O] (2) and/or [LRe(N tBu)2(NH tBu)]2+ (4) can be obtained by the treatment of Re(N tBu)3(OSiMe3) with L. Reaction of 2·BPh4 with trifluoromethanesulfonic anhydride gives [(L - H)Re(N tBu)2(CF3SO3)]BPh4 (3-BPh4). Interaction of [Re(N tBu)2 (OSiMe3)(μ-O)]2 with L yields [LRe(N tBu)O2]+ (5). In contrast to the t-butylimido analogues, only [LRe(NAr)2O]Cl (6·Cl) is isolated from the reaction of Re(NAr)3Cl with excess L. Complexes 2, 5 and 6 are stable in 0.1 M CF3CO2H. Electrochemically, they undergo proton-coupled two electron reductions at pH 1 with Epc; (cathodic peak potential) of -0.30. -0.29 and -0.12 V versus SCE respectively. Constant potential electrolysis of 6 at -0.3 V affords a green solution which is rapidly oxidised in air to give [LRe(NAr)O2]+ (7). The reduction of 5-ClO4 by zinc in the presence of oxalic acid and CF3CO2H affords the rhenium(V) species [LRe(N tBu)(oxalate)]ClO4 (8·ClO4) and [LRe(N tBu)(CF3CO2)2]ClO4 (9·ClO4) respectively. The molecular structures of 2·ClO4,3·BPh4, 5·ClO4, 6·Cl·2H2O. and 8·ClO4 have been determined by X-ray crystal analysis. The Re-N(L) bonds which are trans to imido and oxo ligands are comparatively long (2.344-2.243 Å). The range of Re-N(imido) and Re-O(oxo) distances (1.67-1.78 Å and 1.71-1.76 Å respectively) can be rationalised by the oxo/imido ligand ratio in the Re(VII) complexes. © 1998 Elsevier Science S.A. All rights reserved.link_to_subscribed_fulltex

Reactions of dimesityldioxoosmium(VI) with bidentate N-heterocycles. Crystal structure of a dioxoosmium(VI) complex containing a molecular square

The interaction of OsO2(mes)2 (mes = mesityl) with pyz (pyrazine) gave the pyrazinebridged dimer [OsO2(mes)2]2(μ-pyz) (1), which has been characterized by X-ray crystallography. The structure around Os in 1 is square pyramidal, with the pyrazine, two oxo ligands, and one mesityl group in the square plane. The Os-O distance and O-Os-O angle are 1.71 Å and 147.5°, respectively. The reaction of OsO2(mes)2 with 4,4′-bpy (4,4′-bipyridyl) and bpe (trans-1,2-bis(4-pyridyl)ethylene) in Et2O gave the oligomeric [OsO2(mes)2L]n (L = 4,4′-bpy (2), bpe (3)) in good yields. The 1H NMR spectra of 2 and 3 indicate that L's are coordinated in a symmetric fashion in these oligomers. The reaction of OsO2(mes)2 with 4,4′-bpy in CHCls followed by slow evaporation afforded the crystalline tetramer [OsO2-(mes)2(μ-4,4′-bpy)]4 (4). The crystal structure of the tetramer 4 contains the square-planar [Os(4,4′-bpy)]4 core with octahedral local geometry around each Os. The Os-O distance and O-Os-O angle are 1.6 Å and 159°, respectively. Treatment of OsO2(mes)2 with CNpy (4-cyanopyridine) gave [OsO2(mes)2]·[OsO2(mes) 2(CNpy)] (5). The structure of 5 consists of the four-coordinate [OsO2(mes)2] and five-coordinate [OsO2(mes)2(CNpy)] moieties, which are linked together via the Os=O⋯Os interaction. The Os-O distances in the [OsO2(mes)2] and [OsO2(mes)2(CNpy)] moieties in 5 are 1.69 and 1.71 Å, respectively. The (Os)O⋯Os distance is 2.78 Å, and the Os-O⋯Os angle is 170°. The Os-O stretching frequency for the above dimesityldioxoosmium(VI) complexes correlates well with the Os-O bond order and the coordination environment around Os.link_to_subscribed_fulltex

Clinical Presentations and Outcome of Hospitalised Paediatric Oncology Patients with Laboratory-confirmed Pandemic H1N1 Influenza Infection in Hong Kong MMK SHING Pandemic H1N1 Infection in Paediatric oncology Patients 199

Abstract Objective: The clinical course of hospitalised paediatric oncology patients and haematopoietic stem cell transplant (HSCT) recipients with laboratory-confirmed pandemic H1N1 influenza infection were studied. Methods: Data from oncology patients and HSCT recipients with hospitalised laboratory-confirmed pandemic H1N1 influenza infection in Hong Kong were collected. Parameters on initial presentations, clinical course, treatment regimens and outcome were studied. Results: Sixteen patients were studied, the median age was 12.4 years. Fever (100%), cough (75.0%), runny nose (56.3%) and sore throat (50.0%) were the most common presenting symptoms. Antiviral therapy was started at median 1 day after onset of fever. HSCT recipients were more common to require a repeated or prolonged course of antiviral therapy due to persistent respiratory symptoms. Our cohort recovered without severe complications. Conclusion: Fever, cough, runny nose and sore throat were the most common presenting symptoms. HSCT recipients were more likely to develop persistent or recurrent respiratory symptoms and required repeated course of antiviral therapy. The uncomplicated course of pandemic H1N1 infection of paediatric oncology and HSCT recipients might be related to the early initiation of antiviral therapy

Bio-sludge from the pulp and paper industry as feed for black soldier fly larvae : A study of critical factors for growth and survival

Pulp and paper bio-sludge (PPBS) has low economic value and is therefore often composted or incinerated. The purpose of this work is to evaluate the feasibility of using PPBS to breed black soldier fly (Hermetia illucens) larvae (BSFL), so improving resource efficiency and supplying protein and fat to the animal feed market. BSFL were reared on PPBS in a climate chamber on a laboratory scale in order to assess nutrient deficiency, inhibition and whether the BSFL recycle the PPBS well or not. The PPBS used came from a chemi-thermomechanical pulp/groundwood pulp mill. The effect of supplementing nutrient solution added either into the PPBS or as a free liquid surface were studied. Prepupae dry weight, survival rate until prepupae stage and residual dry PPBS were measured. The addition of reference diet leachate into the PPBS did not have a significant impact on the weight of the prepupae (2.0 mg) but the survival rate was significantly higher (16.0 %). On the other hand, the addition of reference diet leachate as a free liquid surface had a significant impact on both the weight of the prepupae (4.8 mg) and the survival rate (25.7 %). The bio – conversion and PPBS – reduction was as best 0.4 % and 3.2 % respectively. This study has proven that the nutrients in PPBS are not readily available to the larvae. Addition of reference diet leachate increase the survival rate which opens up for possibilities of co-digestion. However, it is clear that under the tested conditions, BSFL is not recycling PPBS well and BSFL as a method for recycling of PPBS need further research