Ultrafast spectroscopy of RuII polypyridine complexes in the gas phase and the liquid phase: [Ru(2,2'-bipyridine)2(nicotinamide)2]2.

[Ru(bipyridine)2(nicotinamide)2]2+ (1) and its monoaqua-complex [Ru(bipyridine)2(nicotinamide)(H2O)]2+ (2) were spectroscopically studied for the first time in the gas phase by static and time resolved UV photodissociation spectroscopy, observing nicotinamide and H2O ligand dissociation for 1 and 2, respectively. Both processes and their ultrafast dynamics were investigated in parallel by transient absorption spectroscopy in aqueous solution. The latter data were newly acquired for the long-wavelength MLCT band excitation of 1 and provide novel ultrafast ligand dissociation results for 2, confirming the gas phase results, i.e., exclusive H2O cleavage over nicotinamide loss. Similar apparent time constants in the sub-ps and few ps ranges were obtained for 1 in both phases, whereas a larger time constant of ca. two hundreds of ps for the ground state recovery was observed exclusively in the solution phase. Our reaction scheme accounts for faster dissociation dynamics in the gas phase by energetical lowering of the 3MC vs. the 3MLCT states by lack of solvent stabilization of the latter. Based on the apparent time constants, we favour, for the solution dynamics, a fast bimodal vibrational deactivation in the 3MLCT/3MC manifolds and a slow dissociation obfuscated by the ground state recovery. This is substantiated by a similar reaction scheme proposed for the ultrafast dynamics of 2, resulting in a new assignment for transient absorption features with λ > 550 nm to the 3MC manifold, and a common kinetic description for 1 and 2. Computations at the TD-DFT/cc-PVTZ/MDF28 level support our spectroscopic findings and the suggested deactivation pathways.

Age-dependent physiological dynamics in acid-base balance, electrolytes, and blood metabolites in growing goats.

There is a paucity of published data reporting acid-base equilibrium in goats, and no information is available on how the acid-base complexity changes when suckling goat kids become ruminants. The aims of this study were to evaluate young healthy goats for age-related changes in serum proteins, metabolites, and electrolytes; differences in results when the Henderson-Hasselbalch equation or strong ion approaches were used were also assessed. To assess biological variability and reproducibility, two consecutive long-term studies, each lasting from the 6th to 56th week of life (wl), were performed in 15 (Study 1) and 10 (Study 2) animals. Blood gas analysis, serum biochemical analysis, and electrophoresis were performed on venous blood, and acid-base information was obtained using the traditional Henderson-Hasselbalch approach, Stewart's strong ion model, and Constable's simplified strong ion model. In all goats within the first 4-5 months, serum concentrations of glucose, l-lactate, and inorganic phosphate decreased significantly, while serum concentrations of total protein, albumin, and gamma globulin increased. Consequently, nonvolatile weak acids (Atot Alb and Atot TP) increased. At the end of this 'adaptation period', i.e. when milk was replaced by purely plant-based food, significantly lower bicarbonate and base excess values were accompanied by blood pH that shifted towards acidosis. Electrolytes (Na+, K+, Ca2+, and Cl-), anion gap, strong ion difference, and strong ion gap did not show age-dependent trends. In conclusion, somatic growth and development of gastro-intestinal fermentation in growing goats act as complex sources of physiological variability on acid-base equilibrium that was not reflected by the Henderson-Hasselbalch equation only.

Photophysical dynamics of a binuclear Cu(i)-emitter on the fs to µs timescale, in solid phase and in solution.

Understanding subtle aspects of photophysical behavior is the key to design and synthesize new and improved luminescent materials. We contribute to this with an in-depth photophysical characterization of the binuclear copper complex Cu(i)-NHetPHOS-tris-m-tolylphosphine (1), a member of a recently established emitter class for ultra-efficient, printed organic light-emitting diodes (OLEDs). To this end we studied 1 in solution and in solid form, i.e. neat film and KBr-pellet, by means of femtosecond time-resolved transient absorption/reflectivity, time-correlated single photon counting (TCSPC), and nanosecond time-resolved step-scan FTIR spectroscopy. Using these methods, we explore the photoinduced dynamics from ultrafast Franck-Condon state deactivation until the decay of the luminescent states. Upon photoexcitation, we observed multiexponential dynamics in both solution (e.g. acetonitrile 0.8 ps, 59 ps, 3 ns, 11-13 ns) and in solid state (e.g. neat film 0.3 ps, 35 ps, 670 ps, 0.5-1 µs, 3.5-4.5 µs) with four to five time-constants that significantly depend on the type of sample. Quantum chemical calculations at the DFT level in combination with step-scan vibrational spectroscopy provided structural information about the electronic ground state S0 and the lowest lying excited state T1, and show that the latter is populated within 1 µs after photoexcitation. We found thermally activated delayed fluorescence (TADF) for this complex, which has been suggested to be the cause for its high efficiency in printed OLED devices. The results suggest that non-radiative processes, lowering the luminescence quantum yield in solution, are active on the ns to µs timescale.

Ultrafast excited-state relaxation of a binuclear Ag(i) phosphine complex in gas phase and solution.

The binuclear complex [Ag2(dcpm)2](PF6)2 (dcpm = bis(dicyclohexylphosphino)methane) exhibits a structure with a close silver-silver contact mediated by the bridging ligand and thus a weak argentophilic interaction. Upon electronic excitation this cooperative effect is strongly increased and determines the optical and luminescence properties of the compound. We have studied here the ultrafast electronic dynamics in parallel in gas phase by transient photodissociation and in solution by transient absorption. In particular, we report the diverse photofragmentation pathways of isolated [Ag2(dcpm)2]2+ in an ion trap and its gas phase UV photodissociation spectrum. By pump-probe fragmentation action spectroscopy (λex = 260 nm) in the gas phase, we have obtained fragment-specific transients which exhibit a common ultrafast multiexponential decay. This is fitted to four time constants (0.6/5.8/100/>1000 ps), highlighting complex intrinsic photophysical processes. Remarkably, multiexponential dynamics (0.9/8.5/73/604 ps) are as well found for the relaxation dynamics in acetonitrile solution. Ab initio calculations at the level of approximate coupled-cluster singles-doubles (CC2) theory of ground and electronically excited states of the reduced model system [Ag2(dmpm)2]2+ (dmpm = bis(dimethylphosphino)methane) indicate a shortening of the Ag-Ag distance upon excitation by 0.3-0.4 Å. In C2 geometry two close-lying singlet states S1 (1MC(dσ*-pπ), 1B, 4.13 eV) and S2 (1MC(dσ*-pσ), 1A, 4.45 eV) are found. The nearly dark S1 state has not been reported so far. The excitation of the S2 state carries a large oscillator strength for the calculated vertical transition (266 nm). Two related triplets are calculated at T1 (3.87 eV) and T2 (3.90 eV). From these findings we suggest possible relaxation pathways with the two short time constants ascribed to ISC/IVR and propose from the obtained similar values in gas phase that the fast solution dynamics is dominated by intramolecular processes. A further relaxation by IC/IVR in the triplet manifold is likely to account for the observed intermediate time constants. For the acetonitrile relaxation dynamics additional modifications are invoked based on solvent-induced shifts of the energy levels and the possible formation of solvent and counterion exciplexes on a longer timescale.

Coxiella burnetii: Serological reactions and bacterial shedding in primiparous dairy cows in an endemically infected herd-impact on milk yield and fertility.

Coxiella burnetii (C. burnetii) is the causative agent of Q fever both in humans and animals. The objectives of this study were to investigate seropositivity and bacterial shedding in heifers and primiparous cows in an endemically infected herd and to assess the effects on post-partum diseases, fertility and milk production. At the age of 9 months, 96 Holstein heifers were included. Sampling was performed reproduction-orientated: at the beginning of the study, at detection of first pregnancy, 3 weeks before expected calving date (blood serum), at parturition and after 21, 42, 100 and 150 days in milk (DIM) (blood serum, vaginal swabs and milk). Serum samples were investigated by a commercial ELISA for the presence of specific antibodies and vaginal swabs and milk samples by PCR to detect C. burnetii DNA. Individual animal data (calving ease, stillbirth, retained foetal membranes, puerperal metritis, endometritis after 42 DIM, presence of corpus luteum after 42 DIM, interval calving-first service, interval calving-conception, number of inseminations until 150 DIM, proportion of pregnant cows until 100 and 150 DIM, proportion of pregnant cows after first service and data of the dairy herd improvement test) were documented. All heifers were seronegative at the age of 9 months and 3 weeks before the expected calving date. Subsequently, the proportion of seropositive animals and the antibody score increased significantly towards 42 and 100 DIM, respectively. Vaginal C. burnetii shedding was highest at parturition (30.9%), while the most positive milk samples were detected after 100 DIM (15.3%). Coxiella burnetii seropositivity and shedding had no impact on parameters of reproduction. However, milk fat yield was declined in puerperal vaginal shedders and cows which seroconverted during their first 42 DIM, respectively.

Effect of Parachlamydia acanthamoebae on pulmonary function parameters in a bovine respiratory model.

The aim of this study was to evaluate pulmonary dysfunction induced by experimental infection with Parachlamydia acanthamoebae in calves. Intrabronchial inoculation with P. acanthamoebae was performed in 31 calves aged 2-3 months old at two different challenge doses of 10(8) and 10(10) inclusion-forming units (IFU) per animal. Control animals received heat inactivated bacteria. The effects on pulmonary gas exchange were determined by arterial blood gas analysis and haemoximetry during the 7 days post inoculation (DPI). For pulmonary function testing (PFT), impulse oscillometry, capnography, and measurement of O2 uptake were undertaken in spontaneously breathing animals 7 and 3 days before inoculation and were repeated until 10 DPI. In the early phase after challenge (1-3 DPI), mild hypoxaemia occurred, which was accompanied by a significant reduction in both tidal and alveolar volumes (each related to bodyweight, BW). In parallel, expiratory flow rate and specific ventilation (i.e. minute ventilation related to O2 uptake) were significantly increased. Minute and alveolar ventilations (each related to metabolic BW) increased significantly due to higher respiratory rates, lasting until 4 and 5 DPI, respectively. Oxygen uptake was slightly reduced during the first 2 days after challenge, but increased significantly during the recovery phase, from 4 to 8 DPI. No deterioration in respiratory mechanics or acid-base balance was observed. Respiratory infection with 10(10) IFU P. acanthamoebae per calf induced mild respiratory dysfunction, mainly characterised by hypoxaemia. The study's findings do not indicate severe pathophysiological consequences of P. acanthamoebae infection on pulmonary function in the bovine host.

Time-resolved IR spectroscopy of a trinuclear palladium complex in solution.

This paper presents a combined spectroscopic and theoretical analysis of a trinuclear [Pd3{Si(mt(Me))3}2] complex (mt(Me) = methimazole) which has been demonstrated to be a potential catalyst for coupling reactions. It is a highly symmetric model system (D3 in the electronic ground state) for the investigation of electronic states and the structure of polynuclear transition metal complexes. Different time-resolved IR spectroscopic methods covering the femtosecond up to the microsecond range as well as density functional computations are performed to unravel the structure and character of this complex in the electronically excited state. These are the first time-resolved IR studies on a trinuclear Pd complex. Based on the interplay between the computational results and those from the IR studies a (3)A state is identified as the lowest lying triplet state which has C2 symmetry.

In-depth exploration of the photophysics of a trinuclear palladium complex.

A detailed theoretical and spectroscopic study on the electronically excited states of a trinuclear palladium complex is presented both in the gas phase and solution. The application of DFT and TDDFT methods as well as a variety of spectroscopic methods to the chosen complex [Pd3{Si(mt(Me))3}2] (1, mt(Me) = methimazole) leads to the first detailed analysis of the photophysics of a symmetric trinuclear complex. In combination with the calculations, energies, structures and lifetimes of the excited electronic states (with an (3)A1 state as the lowest one) are characterized by applying the resonant-2-photon-ionization method in a molecular beam experiment as well as luminescence, time-correlated single photon counting and excited state femtosecond absorption spectroscopy in solution. These investigations are of fundamental interest to analyze photophysical properties of metal containing complexes on a molecular level.

Combined theoretical and experimental study of spin and charge dynamics on the homodinuclear complex [Ni2(II)(L-N4Me2)(emb)].

We present a combined theoretical and experimental study of spin and charge dynamics on the homodinuclear compound [Ni2(II)(L-N4Me2)(emb)]. The theoretically calculated oscillator strengths of the ground-state absorption spectrum show an acceptable agreement with experiment. We predict a local ultrafast laser-induced spin-flip scenario, which involves charge-transfer states. Experimentally, we observe charge dynamics on two different time scales. The two relevant, transient electronic states and their electronic properties are also theoretically characterized. These results provide a joint investigation of the homodinuclear complex and suggest a realistic scenario for ultrafast spin dynamics and other optical-related manipulations.

Treatment options and outcome for renal cell tumors in the transplanted kidney.

The diagnosis of renal cell carcinoma in a transplanted kidney is rare but with possibly devastating consequences. In addition to transplant nephrectomy, which inevitably results in a return to dialysis, various treatment options such as different techniques for nephron sparing surgery and local ablative procedures (like radiofrequency ablation or cryoablation) have been described in the literature. An important issue is to find the balance between the preservation of the transplant function, on the one hand, which is dependent on the maintenance of an immunosuppressive regimen, and a sufficiently radical tumor therapy on the other hand. To provide an overview of current therapeutic attempts to cure transplant renal cell carcinoma under these conditions, published data on related therapies and outcomes are summarized.

Kidney transplantation using donors with history of diabetes and hypertension.

PURPOSE: Due to the persistant organ shortage for kidney transplantation, donor selection has changed in the past years. Although hypertension and diabetes mellitus are known to be risk factors for renal insufficiency, kidneys from donors with these diagnoses in their history have been accepted for kidney transplantation even with an increased risk of poor graft function. Herein we have reported our experience with kidney transplantation using grafts from donors with both, a history of type II diabetes and hypertension. METHODS: Between 2000 and 2005, ten patients were grafted using donors with history of type II diabetes mellitus and hypertension. Mean donor age was 58 +/- 7.5 years and recipient age, 52.2 +/- 15.7 years. Mean HLA mismatch was 0.8 (A); 1.2 (B) and 0.9 (DR). Cold ischemia time was 17.4 +/- 4.1 hours. Immunosuppression was based on CyA (n = 7), tacrolimus (n = 2) or sirolimus (n = 1). RESULTS: Six patients (60%) showed good initial function, and four (40%) had delayed graft function (DGF). One patient died at ten weeks due to multiorgan failure. Two (20%) biopsy-proven rejections were diagnosed, one of which was resistant to therapy. Six months after kidney transplantation, 7 (77%, n = 9) showed good graft function (creatinine 1.3 to 2.4 mg/dL), but one patient displayed long-lasting DGF with poor function. CONCLUSION: Grafts from donors with a history of diabetes mellitus and hypertension are suitable for kidney transplantation. Elevated rate of DGF (40%) would justify allocation of these organs to local transplant centers to shorten ischemia time and thereby reduce DGF and achieve better long-term results. Identification and detailed evaluation of these donors prior to allocation (eg, HbAlc, biopsy) may help transplant centers to accept these kidneys.

Recurrent complicated colon diverticulitis in renal transplanted patient.

Colon perforation due to diverticulitis is a life-threatening complication in the postoperative course of kidney transplantation. In the immunocompromised patient a diagnosis of diverticulitis is difficult to make. We report a 53-year-old woman being kidney transplanted 14 years ago with known diverticulosis. She was admitted with acute severe pain in the lower left abdomen. Abdominal computed tomography (CT) scan indicated a diagnosis of intestinal abscess in the small pelvis. Laparotomy showed a covered sigma perforation with abscess located in the small pelvis (Hinchey-I). Because of the immunocompromised situation of the patient we performed a Hartmann procedure. Her postoperative course was uneventful. In a 6-month interval the intestinal continuity restoration was performed. Twelve days after discharge the patient was readmitted with reduced renal function and increased infection parameters. During physical examination the abdomen was tender. The patient complained of abdominal pain in the left upper abdomen and additional pain in the left shoulder. An antibiotic therapy using ciprofloxacin was already initiated owing to a urinary tract infection. An abdominal CT scan was performed and indicated an intestinal abscess in the left upper abdomen. Laparotomy showed an abscess involving transverse colon, distal jejunum, and proximal ileum (Hinchey-II). Segmental resection of the left colonic flexure, proximal jejunum, and ileum was performed. The postoperative course was uneventful and the patient was discharged on the 8th postoperative day. The present casuistry emphasizes that the immunocompromised patient can undergo diverticulitis twice, and that primary anastomosis is a feasible option for patients with localized peritonitis due to complicated diverticulitis.

Interventional stenting for ruptured iliac aneurysm following transplant nephrectomy.

Surgical removal of a failed kidney graft may lead to a variety of postoperative complications, development of an aneurysm being a relatively rare complication. We report the case of a 34-year-old man who developed an iliac aneurysm 13 years after transplant nephrectomy. Interventional stenting was performed upon the rupture of the aneurysm. Postintervention the function of the contralateral transplanted kidney was stable and the patient recovered. An endoleak was diagnosed after 1 week, which was also stented. No operative procedure was necessary. In conclusion, even in an emergency situation interventional stenting of a false iliac aneurysm after transplant nephrectomy may be a therapeutic option.

Development of a cell culture assay for the quantitative determination of vaccination-induced antibodies in rabbit sera against Clostridium perfringens epsilon toxin and Clostridium novyi alpha toxin.

Cell culture assays are possible alternatives to replace in vivo neutralization tests currently required for potency testing of clostridial vaccines. Cell culture assays based on the MDCK cell line and the Vero cell line which are sensitive to the Clostridium (C.) perfringens type D epsilon toxin and Clostridium novyi type B alpha toxin, respectively, were developed, and the test conditions were standardized. The antibody titres of vaccinated rabbits measured in vitro were compared with the results of current test procedures recommended by European Pharmacopoeia. The correlation coefficients calculated were significant for all sera tested. The cell culture assays proved to be sensitive, specific, reproducible and reliable. Therefore, these cell culture assays could be suitable in vitro alternatives to the in vivo mouse neutralization experiments required for potency tests of clostridial vaccines, but further validation studies are necessary.

Isolation, identification and characterization of group A rotavirus from a chicken: the inner capsid protein sequence shows only a distant phylogenetic relationship to most other avian group A rotaviruses.

Rotavirus particles were identified in the intestinal content of a 35-day-old stunted chicken. The virus was isolated, RNA pattern was analysed and the viral genome segment 6 was sequenced. In particular, the sequence data showed a very close similarity to the chicken rotavirus isolate Ch-1 (99.2% amino acid homology), this is distantly related to all known avian rotaviruses and supports the existence of different VP6 types amongst avian group A rotaviruses.

Therapy and prognosis of tumors of the genitourinary tract after kidney transplantation.

There is an increased incidence of tumors of the genitourinary tract among kidney graft recipients. From 1979 to 2001, all patients who received kidney transplants had records of both their underlying diseases and their initial immunosuppression. Patients who developed a genitourinary tract malignancy were evaluated for tumor type, location, stage, tumor therapy and clinical course. During this period, 1804 patients underwent 2068 kidney transplantations. Thirty-four patients had 39 tumors of genitourinary origin. One patient was lost to follow-up. There were 15 patients with 18 renal cell carcinomas (one of them multifocal): six had seven transitional cell carcinomas; six, prostatic carcinoma; six, tumor of the female genital tract (one also had a renal cell carcinoma); and two, a seminoma. Most tumors were diagnosed in their early stages (< or = pT3, N0, M0; n = 31 tumors) and thus accessible to curative therapy, achieving good long-term results: 1- and 5-year survival rates of 100% and 91%, which were better than those obtained in advanced stages (N+, M+; n = 7 tumors), namely both 1- and 5-year survival rates of 38% (P < .05). Death was caused by tumor growth in nine patients (27%) and by other causes in three patients (9%). With appropriate treatment genitourinary tumors at early stage show a good prognosis. New immunosuppressants with supposed antiproliferative effects may help to decrease the incidence of malignancies. The most important factor is risk-adapted screening to identify malignancies early and to initiate appropriate therapy.

Evidence of infection in tortoises by Chlamydia-like organisms that are genetically distinct from known Chlamydiaceae species.

Nasal lavage fluid was collected from 155 tortoises, mostly Testudo spp., that were kept as companion animals and suffered from nasal discharge. Examination for chlamydial DNA by PCR assays targeting the ompA, ompB, and groESL genes, as well as the 16S rRNA signature region and the 16S-23S intergenic spacer, respectively, revealed 16 (10.3%) positive animals. Sequence analysis of PCR products indicated high homology to the family Chlamydiaceae. Phylogenetic trees constructed from partial sequences of the ompA and 16S rRNA genes showed that the present samples clustered outside the nine species of Chlamydia and Chlamydophila. Sequences of the nearest relative, Chlamydophila pecorum, were still clearly distinct from those of the positive tortoise samples. This suggests that the tortoises had been infected by Chlamydia-like agents, the taxonomic identity and pathogenic importance of which has yet to be established.

Stent migration necessitating surgical intervention.

BACKGROUND: Internal drainage with transhepatically or endoscopically placed endoprostheses has been used for many years as a temporary or definitive treatment for biliary tract obstruction. As a late complication, stent migration may occur. METHODS: We reviewed our records to identify patients who were operated on for a migrated endoprosthesis that was causing complications. In all, five such patients were identified. RESULTS: One patient had a large bowel perforation. Bowel penetration led to an interenteric fistula in one patient and to a biliocolic fistula formation in another. Small bowel distension was found in two patients. Surgical treatment consisted of local excision in three patients, segmental resection in one patient, and a bypass operation in the patient with biliocolic fistula. Postoperatively, four patients recovered without problems, but one patient died during a complicated postoperative course. CONCLUSION: If a stent becomes stuck in the gastrointestinal tract and is not accessible for endoscopic removal, early operative revision is mandatory to prevent further complications.

Influences of naturally occurring and experimentally induced porcine pneumonia on blood parameters.

It had been the objective of the studies described to establish local and systemic changes by naturally occurring pneumonia or pneumonia experimentally induced by Pasteurella multocida and Haemophilus parasuis in swine. Acute and chronic pneumonia was found to alter the cytokine level of lung lavage fluid and affect the composition and function of blood cells, especially with regard to phagocytosis, radical formation and cell surface receptors. Interleukin-6 levels in blood plasma rose 24h after experimental intrabronchial infection. The influences of the changes on growth and meat quality are discussed.