Titanocene dichloride, [Ti]Cl-2 (1) ([Ti] = Ti(eta(5)-C5H4SiMe3)(2)), with one equiv. of the lithium thiolates LiSCHR-2-(C4H3S)-C-c (2a, R = H; 2b, R = Me) gave the appropriate [Ti](Cl)(SCHR-2-(C4H3S)-C-c) compounds (3a, R = H; 3b, R = Me) under mild reaction conditions. Further treatment of 3a,b with another equiv. of thiolates 2a,b produced the respective bis(thiolates) species [Ti](SCHR-2-(C4H3S)-C-c)(2) (4a,b). Titanocenes 4a,b are also accessible, when 1 is reacted with 2a,b in a 1:2 M ratio. The hydrolysis reaction of 4a,b produced the titanoxane cluster 5, consisting of a [Ti'](6)O-9 cage ([Ti'] = Ti(eta(5)-O5H4 SiMe3)) with a silsesquioxane analog structure. The molecular structure of 5 in the solid state is the first example of a trigonal prismatic Ti-6 polyhedron. Upon treatment of 4a,b with MCl2 (M = Pd, Pt), aiming to obtain heterobimetallic coordination complexes, however, either 1 or 3a,b were formed, depending on the reaction conditions. All the compounds have been characterized by elemental analysis, IR, NMR (H-1, C-13{H-1}) spectroscopy and mass-spectrometry. (C) 2018 Elsevier Ltd. All rights reserved.

BACKGROUND AND PURPOSE:Radiofrequency ablation (RFA) was established for minimally invasive treatment of small kidney tumors in multimorbid patients. Bipolar and multipolar RFA may allow the treatment of larger tumors. Safe tumor coagulation depends on total energy supplied and proper electrode placing. To investigate the influence of energy on ablation size and shape in intact kidneys, we used cooled bipolar and multipolar RFA in an in vivo pig model.MATERIALS AND METHODS:Twenty-five male pigs were treated with percutaneous bipolar (one electrode) or multipolar (two electrodes) RFA with various energy transfer under laparoscopic visual control. The animals were sacrificed 4 to 5 hours after RFA. Volume and shape of the coagulation zone was analyzed by three-dimensional reconstruction of hematoxylin and eosin and diaminobenzidine stained paraffin serial sections. Heat-induced cellular activation was addressed by immunohistologic detection of apoptosis marker proteins heat shock protein 70 (Hsp70) and caspase-3 (Casp3).RESULTS:Multipolar RFA led to significant larger tissue ablation than bipolar RFA. Increasing energy, however, did not result in significant enlargement of the coagulation volume. Shape control was better in bipolar RFA. Hsp70 and activated Casp3 immunoreactivity were increased close to the central coagulation zone and occasionally in the caliceal system.CONCLUSIONS:RFA causes minimal tissue damage beyond the primary coagulation zone, indicating that RFA is a safe, minimally invasive method for treatment of renal tumors. The ablation of larger volumes necessitates further improvement of multipolar RFA. These findings may be of general interest, because treatment failure correlates with mass size in monopolar RFA and cryoablative techniques as well.

Introduction: Knowledge about the changes in the electric conductivity during the coagulation process of radiofrequency ablation of the liver is a prerequisite for the predictability of produceable thermonecrosis in the liver.Materials and methods: Continuous measurements of the electric conductivity sigma in ex vivo porcine liver (n = 25) were done during the coagulation and cooling process at the temperature range of the radiofrequency ablation at a frequency of 470 kHz relevant for the radiofrequency ablation. Measurements of the electric conductivity were performed in both perfused porcine liver (n = 3) and a human surgical specimen from a colorectal liver metastasis.Results: At a body temperature of 37 degrees C, conductance sigma was 0.41 siemens per metre (0.32 S/m; 0.52 S/m). Conductance sigma increased continuously and uniformly at a temperature of 77 degrees C. Maximum conductance sigma with 0.79 S/m (0.7 S/m; 0.87 S/m) was reached at 80 degrees C. A continuous reduction of conductance was observed during the cooling phase. At 37 degrees C, the specific conductance sigma in the healthy perfused porcine liver was 0.52 S/m, 0.55 S/m and 0.57 S/m (mean 0.55 S/m). The electric conductivity of the human colorectal liver metastasis was clearly higher.Conclusion: Changes in the specific conductivity during the coagulation and the cooling phase play an important role for the produceable size of a coagulation necrosis and necessitates an adaptation of the therapy parameters during radiofrequency ablation.

Central nervous system involvement in trichinosis is rare. Computed tomography (CT) findings in neurotrichinosis are well described, but there are only a few reports about magnetic resonance (MR) appearances. Several pathological mechanisms have been suggested to explain neurological complications. Using sequential diffusion-weighted and conventional MR imaging, we were able to demonstrate bilateral watershed infarction due to eosinophilic vasculitis as the underlying cause of CNS involvement.

The title compound crystallizes in the monoclinic space group P21/n with a = 12.3727(4), b = 20.0249(5), c = 17.9607(6)Å, β = 97.002(1)°, V = 4416.8(2)Å3, and Z = 4. The crystal structure consists of a discrete [{[Ti](μ-σ,π-C≡CSiMe3)2}Cu(phen)]+ cation (phen=1,10-phenanthroline) and a non-coordinated BF4- counter-ion, whereby the copper(I) ion is four-coordinated by the two alkynyl ligands of the Ti(C≡CSiMe3)2 unit and the bidentate phen building block, and hence a 18-valence electron count is fullfilled. The Ti(C≡CSi)2 plane is oriented perpendicular to the planar [Cu(phen)]+ arrangement.

Complexes of type {cis-[Pt](mu-sigma,pi-C=CPh)(2)}AgX (3a, [Pt] = (bipy')Pt, X = FBF3; 36, [Pt] = (bipy')Pt, X = FPF5; 3c, [Pt] = (bipy)Pt, X = OClO3; 3d, [Pt] = (bipy')Pt, X = BPh4; bipy' = 4,4'-dimethyl-2,2'-bipyridine; bipy = 2,2'-bipyridine) are accessible by combining cis-[Pt](C=CPh)(2) (la, [Pt] = (bipy')Pt; 1b, [Pt] = (bipy)Pt) with equimolar amounts of [AgX] (2a, X = BF4; 2b, X = PF6; 2c, X = ClO4; 2d, X = BPh4). In 3a-3d the platinum(II) and silver(I) ions are connected by sigma- and pi-bonded phenyl acetylide ligands. When the molar ratio of 1 and 2 is changed to 2:1 then trimetallic [1 cis-[Pt](mu-C=CPh)(2)](2)Ag]X (8a, [Pt] = (bipy)Pt, X = BF4; 8b, [Pt] = (bipy')Pt, X = PF6; 8c, [Pt] = (bipy)Pt, X = BF4) is produced. The solid state structure of 8a was determined by single X-ray crystal structure analysis. In 8a the silver(I) ion is embedded between two parallel oriented cis-[Pt](C=CPh)2 units. Within this structural arrangement the phenyl acetylides of individual [Pt](C=CPh)2 entities possess a p-bridging position between Pt(II) and Ag(I). In addition, a very weak dative Pt -> Ag interaction is found (Pt-Ag 2.8965(3) angstrom). The respective silver carbon distances Ag-C-alpha (2.548(7), 2.447(7) angstrom) and Ag-C-beta (3.042(7), 2.799(8) angstrom)(PtC alpha=C beta Ph) confirm this structural motif.Complexes 8a-8c isomerize in solution to form trimetallic [{cis-[Pt](mu-sigma,pi-C=CPh)(2)](2)Ag]X (9a, [Pt] = (bipy)Pt, X = BF4; 9b, [Pt] = (bipy')Pt, X = PF6; 9c, [Pt] = (bipy)Pt, X = ClO4). In the latter molecules the organometallic cation [{cis-[Pt](mu-sigma,pi-C=CPh)(2)](2)Ag](+) is set-up by two nearly orthogonal positioned [Pt](C=CPh)2 entities which are hold in close proximity by the group-11 metal ion. Within this assembly all four PhC C units are eta(2)-coordinated to silver(I). A possible mechanism for the formation of 9 is presented.(c) 2007 Elsevier B.V. All rights reserved.

OBJECTIVE To investigate the technical characteristics of a newly developed device for bipolar and multipolar radiofrequency ablation (RFA) of kidney tissue with a resistance‐controlled power output. MATERIALS AND METHODS The standardized model of the isolated perfused ex vivo porcine kidney was used. Two different applicators (20 and 30 mm active length) were selected for bipolar RFA, and one pair of applicators (2 × 30 mm active length) for multipolar RFA. RF energy was applied at different power levels (20, 30, 60 W) depending on the total active length of the electrodes. Treatment times were 1, 3, 5 and 9 min. The ablation cycles were recorded in continuous digital real‐time and displayed on a monitor showing pre‐set power, actual applied power, applied energy, tissue resistance, and impedance. Lesion sizes were measured macroscopically. A coagulation coefficient (coagulated tissue volume per applied energy unit) was calculated. RESULTS There was a dosage‐effect relationship between the generator power/treatment time and the sizes of the lesions. With increasing treatment time, less tissue volume was coagulated per unit of applied energy. The actual applied energy was lower than that calculated theoretically. The resistance and impedance values for the 30‐W applicator were lower than those of the 20‐W applicator. CONCLUSIONS The technical features of this RFA device, with internally cooled bipolar and multipolar applicators and a resistance‐controlled power output, represents an innovative improvement in RF technology. In vivo studies are needed to confirm the expected advantages and the suitability of this device for complete and reliable ablation of renal tumours.

Purpose: We investigated a newly developed bipolar and multipolar RF ablation system with an internally cooled electrode and resistance controlled power output in a standardized model of perfused ex vivo kidney tissue.Materials and Methods: RF energy was applied at different power levels (20, 30 and 60 W) for 1, 3, 5 and 9 minutes. Each treatment parameter was repeated 5 times. For the 20/30 W levels a bipolar electrode with an active conducting part of 20/30 mm was selected. At 60 W 2 bipolar electrodes with an active conducting part (30 mm each) were connected. Lesion volumes and shapes were calculated by measuring the maximum vertical, long axis and short axis diameters of the macroscopic lesion.Results: Lesion volume increased significantly with the treatment time and generator power applied (p < 0.0001). Lesion size in multipolar ablated zones was larger than that in bipolar ablated zones. A reliable dose-effect relationship existed between the generator power/applied treatment time and ablated tissue lesion size. All lesions were elliptical.Conclusions: Bipolar and multipolar RF ablation with an internally cooled electrode and tissue resistance control represent an interesting advance in RF technology. The development of lesion size and volume is predictable, while a uniform lesion shape can be achieved in perfused ex vivo kidney tissue. Further in vivo trials are required to test whether complete and reliable tumor tissue ablation is possible with this system.

BACKGROUND:Only monopolar systems have thus far been available for radiofrequency ablation of liver tumors, whose application is restricted because of the incalculable energy flow, reduction of electrical tissue conduction, and limited lesion size. The aim of this study was to evaluate a novel internally cooled bipolar radiofrequency application device under in vivo conditions and to compare the effect of this system on lesion size when combined with hepatic arterial microembolization or complete hepatic blood flow occlusion. MATERIALS AND METHODS:In a porcine liver model, RFA (60 W, 12 min) was performed with either normal (n = 12), partially interrupted (arterial microembolization via a hepatic artery catheter n = 12) or completely interrupted hepatic perfusion (Pringle's maneuver, n = 12). RFA parameters (impedance, power output, temperature, applied energy) were determined continuously during therapy. RFA lesions were macroscopically assessed after liver dissection. RESULTS:Bipolar RFA induced clinical relevant ellipsoid thermal lesions without complications. Hepatic inflow occlusion led to a 4.3-fold increase in lesion volume after arterial microembolization and a 5.8-fold increase after complete interruption (7.4 cm(3)versus 31.9 cm(3)versus 42.6 cm(3), P < 0.01). CONCLUSIONS:The novel bipolar RFA device is a safe and effective alternative to monopolar RFA-systems. Interrupting hepatic perfusion significantly increases lesion volumes in bipolar RFA. This beneficial effect can also be achieved in the percutaneous application mode by RFA combined with arterial microembolization via a hepatic artery catheter.

The synthesis of heterobimetallic titanium(IV)–copper(I) complexes of type {[Ti](CCSiMe3)2}CuR {3a, R=iC3H7; 3b, R=nC4H9; 3c, R=cC5H9; 3d, R=9-C13H9; 5a, R=1-C10H7; 5b, R=9-C14H9; [Ti]=(η5-C5H4SiMe3)2Ti} in which monomeric low-valent copper(I) organyls (CuR) are stabilised by the chelating effect of the organometallic π-tweezer [Ti](CCSiMe3)2 are accessible by the reaction of {[Ti](CCSiMe3)2}CuSC6H4CH2NMe2-2 (1) with equimolar amounts of ER (E=Li, BrMg). These species feature monomeric copper alkyls or aryls, bearing β-hydrogen atoms (complexes 3a–3c) or condensed aromatic π-systems (complexes 5a and 5b). While 3a–3d, 5a and 5b are stable at low temperature in the solid-state, it appeared that in solution 3a–3c undergo β-hydride elimination, affording propene (3a), 1-butene (3b) or cyclopentene (3c). Next to these species, HSiMe3 (8) along with the dimeric titaniumcopper acetylide {[Ti](CCSiMe3)(CuCC)}2 (6) is also formed. In contrast, 5b decomposes on heating (30°C) to afford the tweezer molecule [Ti](CCSiMe3)2 (9) and (C14H9)2 (10). Possible reaction mechanism for the latter reactions will be discussed. The solid-state structure of 3b is reported. Complex 3b crystallizes in the triclinic space group P1̄ with cell parameters a=13.659(2), b=17.270(3), c=18.106(4) Å, α=107.64(3), β=100.11(3), γ=108.51(3)°, Z=4 and V=3681(1) Å3. The most striking structural feature of 3b, which will be discussed, is that the nC4H9 moiety is orientated out of the Ti(CCSi)2Cu plane.

K3[Ag(CN)4] (2) reacts with {[Ti](CCR)2}AgOClO3 {R = SiMe3, 1a; R = Ph, 1b; [Ti] = (η5-C5H4SiMe3)2 Ti} in a 1∶4 molar ratio to produce the nonametallic Ag5Ti4 species [Ag(CN→Ag{(RCC)2[Ti]})4 ](ClO4) (R = SiMe3, 3a; R = Ph, 3b) in which four heterobimetallic titanium(IV)–silver(I) tweezer units, [{[Ti](CCR)2}Ag]+, are bridged by a [Ag(CN)4]3− core; the reaction chemistry of 3 is reported.

Chronic persistent osteitis/osteomyelitis is defined as an acute bone infection persisting for more than six weeks despite adequate therapy. Chronic infection may persist for a life-time. Infected tissues with impaired perfusion have been shown to benefit form hyperbaric oxygen (HBO) therapy. Multiple surgical interventions and long-term antibiotic therapy are regularly necessary in osteomyelitis. Limb salvage is not always possible. Therapy of various orthopaedic diseases with HBO is established. Specifically, in chronic osteitis/osteomyelitis, adjunctive HBO therapy is an effective modality within the multidisciplinary treatment concept