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Background In the current guideline of the ESC, in patients with very high cardiovascular risk such as coronary heart disease (CHD) a treatment target for LDL-C Methods The primary objective of this prospective, multi-centre register study was the question of the guidance-based adaptation and adherence to lipid-lowering therapy during and after a cardiac rehabilitation in 1,100 patients with CHD up to 12 months after discharge from the six rehabilitation clinics involved. Patients were included from 2016 to 2018. Results The median age of the 1,100 patients was 63.4±10.4 years, the mean BMI was 28.5±4.7kg/m2, and 24.1% of patients were female. 12.2% were active smokers, 91.6% reported dyslipoproteinemia, 33.9% suffered from diabetes mellitus and 86.5% from hypertension. The majority of patients were included with the main indications NSTEMI (31.6%), STEMI (29.6%) and after CABG surgery (26.4%). The proportion of patients treated with statins was more than 94% when admitted and discharged from the rehabilitation clinic, as well as in 3- and 12-months follow-ups. Approximately 9% of patients were treated with ezetemibe at baseline. On discharge from the rehabilitation clinic 23% of patients were treated with ezetemibe, which remains stable at 3 and 12 months. PCSK9 inhibitors were used in 0.1–0.3% of patients at all times. The adjustment of LLT during three week cardiac rehabilitation resulted in median LDL-C values of 2.27mmol/l (1.80/2.84) at baseline, 1.97mmol/l (1.57/2.47) on discharge (p The proportion of patients with LDL-C Discussion In the context of cardiac rehabilitation, an effective adjustment of LLT is carried out, which resulted in a significant reduction of LDL-C. However, despite a high percentage of patients on statins and ezetemibe, the proportion of patients in the new target range Figure 1 Funding Acknowledgement Type of funding source: Private company. Main funding source(s): This study was supported by an unrestricted grant from Sanofi-Aventis Germany.

Auf dem Boden einer Endometriose konnen potenziell maligne Tumoren entstehen. Diese maligne Transformation kann jedes Gewebe betreffen, in dem auch Endometriose vorkommt. Eine direkte Kanzerisierung benigner Endometriose uber Atypien erscheint moglich. Histologisch handelt es sich bei den endometrioseassoziierten Malignomen uberwiegend um klarzellige oder endometrioide Karzinome, seltener auch um andere histologische Typen. Das Risiko einer malignen Transformation von Endometriosegewebe wurde in alteren Arbeiten mit etwa 1 % angegeben, bei ovariellen Endometriomen mit 2,5 % bei einer Spannbreite zwischen 2 und 17 %. Molekularbiologisch wurden dabei PTEN- und ARID1A-Mutationen sowie Heterozygotieverlust beschrieben. Im Falle von ovariellen Manifestationen wurde eine bessere Prognose dieser Tumoren im Vergleich mit „high-grade“-serosen Ovarialkarzinomen diskutiert. Die Stiftung Endometrioseforschung (SEF) fuhrt derzeit gemeinsam mit der Arbeitsgemeinschaft Gynakologische Onkologie (AGO) eine retrospektive Studie zur Charakterisierung endometrioseassoziierter Malignome inklusive einer histopathologischen Zweitbegutachtung in einem Referenzlabor durch.

The synthesis of 2,4,6-triphenylphosphinine has been revisited and a general protocol for the preparation of such low-coordinate phosphorus compounds in good to excellent yields could be established. This allows to investigate several aspects of the chemistry of 2,4,6-triarylphosphinine, such as the reaction with in situ generated benzyne to give 2,4,6-triphenylphosphabarrelene. The corresponding 2,4,6-triphenylphosphabarrelene-selenide could be characterized crystallographically for the first time and the structural and electronic properties of this cage-compound in comparison to classical triarylphosphines could be evaluated. Moreover, [(L)W(CO)5)] complexes of both 2,4,6-triphenylphosphinine and 2,4,6-triphenylphosphabarrelene were prepared and characterized by means of X-ray crystallography. This allowed for the first time a direct structural comparison of these related phosphorus compounds, coordinated to the same metal fragment.

Auf dem Boden einer Endometriose konnen maligne Tumoren entstehen; dabei fallen etwa 80 % auf Ovarialkarzinome und etwa 20 % auf extragonadale Manifestationen. Diese maligne Transformation kann jedes Gewebe betreffen, in dem auch Endometriose vorkommt. Eine direkte Kanzerisierung benigner Endometriose uber Atypien erscheint moglich. Histologisch handelt es sich bei den endometrioseassoziierten Malignomen uberwiegend um endometrioide oder klarzellige Karzinome, seltener um andere histologische Typen, wie seromuzinose Bordeline-Tumoren, endometriale Stromasarkome, Adenosarkome u. a. Das Risiko einer malignen Transformation von Endometriosegewebe bzw. deren Pravalenz wurde in alteren Arbeiten mit insgesamt 1 % angegeben, bei ovariellen Endometriomen mit 2,5 % bei einer Breite zwischen 2 und 17 %. Molekularbiologisch wurden PTEN- und ARID1a-Mutationen sowie Heterozygotieverlust gefunden. Klinisch wird eine bessere Prognose dieser Tumoren im Vergleich mit high-grade serosen Ovarialkarzinomen diskutiert. Insgesamt liegen in der Literatur nur wenige systematische Studien zu diesen Malignomen vor. Die Stiftung Endometrioseforschung fuhrt gemeinsam mit den Kommissionen Ovar und Uterus der Arbeitsgemeinschaft Gynakologische Onkologie (AGO) aktuell eine retrospektive Studie zur Charakterisierung endometrioseassoziierter Malignome durch (EAM-Studie); ihr Herzstuck ist die histopathologische Zweitbegutachtung in einem Referenzlabor.

This study investigated the prognostic role of tumor cell expression of erythropoietin (EPO) and its receptor (EPO-R) in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN) treated with surgery plus radiotherapy. The impact of EPO, EPO-R, and 11 additional factors on locoregional control (LRC), metastases-free survival (MFS), and overall survival (OS) was retrospectively evaluated in 144 patients. Additional factors were age, gender, performance status, preradiotherapy (pre-RT) hemoglobin levels, tumor site, histologic grade, T category, N category, human papillomavirus (HPV) status, extent of resection, and chemotherapy. Univariate analyses were performed with the Kaplan–Meier method and the log-rank test, multivariate analyses with the Cox proportional hazard model. On multivariate analysis, improved LRC was significantly associated with no EPO expression (risk ratio [RR] 3.72; 95 % confidence interval [CI] 1.35–15.42; p = 0.008), lower T category (RR 1.60; 95 %CI 1.14–2.32; p = 0.005), and oropharynx or larynx cancer (RR 1.23; 95 %CI 1.02–1.49; p = 0.033). Improved MFS was significantly associated with no EPO expression (RR 5.45; 95 %CI 1.13–97.81; p = 0.031), lower T category (RR 1.66; 95 %CI 1.11–2.65; p = 0.013), lower N category (RR 2.44; 95 %CI 1.04–6.66; p = 0.039), HPV positivity (RR 3.14; 95 %CI not available; p = 0.034), and oropharynx or larynx cancer (RR 1.28; 95 %CI 1.01–1.61; p = 0.041). Improved OS was significantly associated with no EPO expression (RR 4.77; 95 %CI 1.63–20.68; p = 0.003), no EPO-R expression (RR 2.36; 95 %CI 1.22–4.92; p = 0.010), lower T category (RR 1.44; 95 %CI 1.04–2.04; p = 0.027), oropharynx or larynx cancer (RR 1.30; 95 %CI 1.08–1.57; p = 0.007), and pre-RT hemoglobin ≥ 12 g/dl (RR 1.94; 95 %CI 1.03–3.65; p = 0.042). EPO expression of tumor cells was an independent prognostic factor for LRC, MFS, and OS. EPO-R expression was an independent prognostic factor for OS.

Myocarditis is a disease which is difficult to diagnose and which includes a risk of the development of dilated cardiomyopathy and sudden cardiac death.In this study 102 patients were included from the time period 2003-2013 after diagnosis or suspected diagnosis of myocarditis in the department of internal medicine at the University Hospital Halle (Saale).Of the study participants 77.5% were male and the average age was 35.5 ± 14.1 years. The symptoms reported by the patients were angina in 46.1%, dyspnea in 38.2%, performance deterioration in 29.4%, palpitations in 9.8% and syncope in 8.8%. In 45.1% of patients, symptoms were preceded by a respiratory infection. All patients underwent an echocardiogram and in 36.5% it was possible to demonstrate a regional wall motion abnormality and in 20.4% a pericardial effusion. A myocardial biopsy was performed in 15.6% of the patients. The presence of cardiotropic viruses was investigated in 37.3% of patients but was detected in only 5.9%. Cardiac magnetic resonance imaging (MRI) was performed in 82 patients of whom 33.3% showed a late enhancement and 11.9% a wall movement disorder. In this study four patients, all male, died and three suffered recurrent myocarditis.This study showed the wide range of symptoms in myocarditis. Myocarditis is rarely severely manifested and in this study the mortality was 3.9%. For further optimization of the diagnostic and treatment algorithms, prospective, randomized studies would be desirable.

Assessments of physical and physiological performance tests in soccer sports are still unspecific yet. There is also a lack of scientific validation using those as a "golden standard". Concerning match performance a large deficit also exist in sports and medical science.The aim and purpose of this multicentric and prospective diagnostic study was to evaluate the validity of current established and recommended diagnostic tests for endurance and match performance (golden standard: real time of playing) in soccer.In a prospective study protocol two German soccer teams from the fourth (n = 22) and third (n = 24) national league first underwent different tests of performance and diagnostics ahead of the competition season (tapping, drop jump, counter movement jump, speed dribbling, treadmill running test). Afterwards, match performance of each athlete was assessed by real time of playing (as a surrogate parameter) during the half season (14 and 25 matches). We finally compared test parameters with the match performance in a linear regression analysis.Our analysis showed no statistical relevant relationship between test parameters and match performance (r(2)0.10). Only the assessment in maximum of relative oxygen uptake during the treadmill test for endurance was associated with a higher amount of variance (12%).According to the study results there is no relevant and valid correlation between current established diagnostic tests in soccer sport and sport-specific performance. The time of real engagement during a match might be associated with a quality of performance for the single athlete. Therefore, the assessment of this match activity is the most important parameter for improving diagnostic tests in soccer. The existence of a "golden standard" is essential for validation of any tests and parameters and the development of new specific assessments. At the moment, physical performance tests have no scientific evidence in soccer sports.

In patients younger than 40 years, renal cell carcinoma and metastases to the bladder are rare. Comparative genomic hybridisation (CGH) may be useful to differentiate between metastatic renal cell carcinoma and secondary malignancies of the genitourinary tract, which can occur in all histologic types. We report the case of a 35-year-old patient with renal cell carcinoma in whom only CGH could help differentiate between a second primary malignancy in the bladder and an atypical bladder metastasis.

A histopathologically confirmed biopsy is the gold standard for the diagnosis of vasculitis. Possible etiologies include primary systemic vasculitis, secondary vasculitis or isolated single organ vasculitis, although on histopathological grounds alone a clear differentiation is frequently not possible. The key criteria of morphological vasculitis work-up include vessel size, type of inflammation (granulomatous, necrotizing and/or leukocytoclastic) as well as the presence or absence of immune complexes and extravascular inflammatory changes. Together with the typical organ involvement and serological data, these criteria constitute the basis of vasculitis classification. Differential diagnostic overlaps and possible discrimination methods are presented. In the same way that the clinical approach of vasculitis patients is an interdisciplinary one, histopathology can only provide a definite diagnosis in combination with clinical and serological data. A conclusive morphological diagnosis depends on the right time of biopsy and the selection of appropriate biopsy material.

SummaryPreoperative quantification of (relative) pulmonary lobar perfusion fraction using scintigraphy is established in predicting lung function after pulmonary surgery. Aim was to develop an easy and truly anatomical method for relative pulmonary lobar perfusion fraction quantification using SPECT/CT and to compare results with those from planar analyses in lung cancer patients. Patients, methods: 36 patients with operable lung cancer, borderline lung function referred to pre-operative quantification. Perfusion SPECT-data were acquired p.i. of 163±9 MBq 99mTc-MAA, subsequent low-dose-CT (SymbiaT, Siemens). Iterative Flash3D-reconstruction, manual 3D segmentation of all lobes using PMOD. VOI transfer to coregistered perfusion SPECTdata, calculation of lobar fractions. Modelbased calculation of relative lobar fractions based on planar data, analysis of planar vs. 3D results using t-test. Results: Significant differences (p

Beim duktalen Carcinoma in situ (DCIS) handelt es sich um eine heterogene Gruppe von Lasionen, deren Klassifikation und Therapie derzeit Gegenstand vieler Diskussionen ist. War bis vor wenigen Jahrzehnten noch die Mastektomie die Standardtherapie, wird heute in Analogie zum invasiven Mammakarzinom zunehmend die brusterhaltende Behandlung angestrebt. Studien belegten, dass eine adjuvante Strahlentherapie das DCIS-Lokalrezidivrisiko um 40–60% senkt. Patientinnen mit einem erhohten Risiko (Frauen

Background: Mutations in NOD2, a putative intracellular receptor for bacterial peptidoglycans, are associated with a subset of Crohn’s disease but the molecular mechanism linking this protein with the disease pathogenesis remains unclear. Human α defensins (HD-5 and HD-6) are antibiotic effector molecules predominantly expressed in Paneth cells of the ileum. Paneth cells also express NOD2. To address the hypothesis that the function of NOD2 may affect expression of Paneth cell defensins, we compared their expression levels with respect to NOD2 mutations in Crohn’s disease. Methods: Forty five Crohn’s disease patients (24 with NOD2 mutations, 21 with wild-type NOD2) and 12 controls were studied. Real time reverse transcription-polymerase chain reaction was performed with mucosal mRNA for HD-5, HD-6, lysozyme, secretory phospholipase A 2 (sPLA 2 ), tumour necrosis factor α, interleukin 8, and human hypoxanthine phosphoribosyltransferase (housekeeping gene). Immunohistochemistry with anti-HD-5 and histological Paneth cell staining were performed in 10 patients with NOD2 mutations or wild-type genotypes. Results: Ileal expression of HD-5 and HD-6, but not sPLA 2 or lysozyme, were diminished in affected ileum, and the decrease was significantly more pronounced in patients with NOD2 mutations. In the colon, HD-5, HD-6, and sPLA 2 were increased during inflammation in wild-type but not in NOD2 mutated patients. In both the colon and ileum, proinflammatory cytokines and lysozyme were unaffected by NOD2 status. Immunohistochemistry identified Paneth cells as the sole source of HD-5. Conclusion: As alpha defensins are important in the mucosal antibacterial barrier, their diminished expression may explain, in part, the bacterial induced mucosal inflammation and ileal involvement of Crohn’s disease, especially in the case of NOD2 mutations.

The transmembrane HER-2 receptor is 185 kD of molecular weight and is encoded by the proto oncogene HER-2 on the long arm of chromosome 17 (17 q 12-21). Over-expression of HER-2 is found in about one third of all breast carcinomas. Determining the HER-2 status is a prerequisite for the use of the monoclonal antibody trastuzumab (Herceptin) in the therapy of metastatic breast cancer. Various test assays for HER-2 either on the protein level (immunhistochemistry [IHC], enzyme-linked immunosorbent assay [ELISA], western blot) or on the gene level (fluorescence in situ hybridization [FISH], chromogenic in situ hybridization [CISH], polymerase chain reaction [PCR], and southern blot) are available. However, IHC and FISH are most often applied. For routine HER-2 testing a combination of both methods is recommended. IHC should be used for screening, followed by FISH only in those cases scored as 2 + by the HercepTest. In future, CISH may represent a useful alternative to FISH. In CISH fluorescent dyes are replaced by chromogenes, facilitating the use of light microscopes and the filing of slides. Quantitative analysis of the shed extracellular domain of HER-2 (HER-2 ECD) in the patients' serum by ELISA is helpful for clinical use. With HER-2 ECD as a surrogate marker of the tumor volume monitoring of adjuvant therapies and tumor recurrence would be feasible. However, more prospective studies with higher numbers of patients are required for validation of these new methods.

Chorioangiomas are benign angiomatous tumours of the placenta occurring with a frequency of approximately one per cent of all examined placentae. Hypoxia and genetic factors are discussed to be predisposing factors for chorioangiomas. However, not much is known about the tumorigenesis of these benign tumours. Screening with various antibodies in a rare case of chorangiomatosis, we found disseminated spindle cells coexpressing vascular epithelial growth factor (VEGF), neutral endopeptidase 24.11 (NEP/CD10), and KIT protein (CD117) within the tumour stroma. A possible involvement of such factors in angiogenesis and tumorigenesis of chorioangiomas/chorangiomatosis has not been studied so far. Seven placentae with chorioangiomas ( n =6) or chorangiomatosis ( n =1), six normal placentae, and four cutaneous haemangiomas were analysed immunohistochemically (ABC and APAAP methods) using antibodies against VEGF, NEP, KIT protein, as well as endothelial markers like PECAM-1 (CD31), CD34, v. Willebrand factor (factor VIII), and ulex europaeus. In addition, analysis of c-kit ‘gain of function’ mutation Asp 816 to Val by means of Hinfl digestion and direct sequencing of semi-nested polymerase chain reaction products was performed. All chorioangiomas and haemangiomas strongly expressed the endothelial markers CD34, CD31, and FVIII, while only weak expression of ulex lectin was noted. Disseminated groups of VEGF-, NEP-, and KIT protein-positive spindle cells, which coexpressed vimentin and smooth-muscle actin were identified as myofibroblasts in the stroma of four chorioangiomas. These spindle cells were quantified as numerous in two and as rare in two other cases. No VEGF-positive myofibroblasts, however, were detected in the villous stroma of normal control placentae and haemangiomas. Only scattered perivascular myofibroblasts expressing KIT protein and NEP were detected in early gestational placenta controls. In all chorioangiomas and chorangiomatosis PCR analysis failed to unveil c-kit ‘gain of function’ mutation Asp 816 to Val in KIT protein-positive spindle cells. Moreover, a significant increase in mast cells was observed only in the haemangiomas. As expected, endothelial origin of chorioangiomas/chorangiomatosis was verified by CD31, CD34, FVIII expression. Myofibroblastic spindle cells expressing VEGF and NEP may be precursor cells in these peculiar angiomatous tumours. Although activating c-kit mutation Asp 816 to Val was not detected by PCR, the presence of KIT protein (CD117)-positive intratumoral myofibroblastic spindle cells in chorioangiomas and chorangiomatosis might suggest involvement of the stem cell factor (SCF)-receptor in pathologically enhanced angiogenesis.

Chorangioma is a benign angiomatous tumor of the placenta occurring with a frequency of approximately 1 % of all examined placentas. Pregnancies especially with large chorangiomas are frequently complicated by abruptio placentae, premature labour, fetal anaemia, hydrops, cardiomegaly and polyhydramnios. We here report a case of an extremely rare chorangiomatosis. Multiple chorangiomas measuring up to 1.5 cm comprised approximately one third of the placenta. A caesarean section had to be performed at 36 weeks of gestation because of uteroplacental insufficiency with oligohydramnios. Displacement of normal placental parenchyma by chorangiomatosis as a cause of uteroplacental insufficiency is very likely. Colour doppler imaging allows early diagnosis and management of chorangiomas. Thus, in our case early diagnosis of uteroplacental insufficiency was rendered. Principally, early diagnosis of fetal hazard due to myocardial insufficiency of the fetus is feasible. In-utero-endoscopy permits prenatal laser devascularisation of large chorangiomas. In the reported case the pregnancy was closely monitored with colour flow imaging. The diagnosis of uteroplacental insufficiency was established because of abnormal blood flow of the uterine arteries and abnormal fetal heart rate (FHR). At the same time fetal cardiomegaly and pathologic blood flow of the ductus venosus in terms of beginning fetal myocardial insufficiency was recognized. Consequently, caesarean section could be performed opportune.

There are clearly no complex and sports-specific tests in handball. So far, no specific complex test has been developed and verified for its intraobserver reliability (IR).The aim of this study was to determine the IR of the Handball-specific complex test (HBKT).The HBKT was applied twice at an interval of two days to two teams of the German Third League (n = 30; age 25.7 ± 3.9 years, range: 19 - 33 years). Within the HBKT, the stress parameters lactate and heart rate as well as the loading parameters time, throwing velocity and number of errors were collected.Overall, 23 % (3/13) of the stress parameters showed a high relative [intraclass correlation coefficient (ICC) 0.75] and absolute [coefficient of variation (CV) ≤ 5 %] IR. On average, a sufficient absolute (∅CV = 11.3 %) and relative (∅ICC = 0.67) IR was observed. Without the parameters "missed throws" and "technical errors" in both rounds, the IR increased significantly (∅ICC: from 0.67 to 0.72∅CV from 11.3 to 6.3 %). The heart rate was comparatively more reliable than lactate (∅ICC = 0.71∅CV = 4.23 % vs. ∅ICC = 0.65∅CV = 15.1 %). With respect to load parameters in round one, 50 % (5/10) showed a high IR; in round two, these values decreased to 40 % (4/10). The mean IR of the parameters in round one was higher than in round two (∅ICC = 0.71∅CV = 12.2 % vs. ∅ICC = 0.60∅CV = 14.3 %). Overall, there was an improvement of the athletes in most stress and load parameters from session one to session two.The HBKT can be attested with a sufficient intraobserver reliability. When the parameters "missed throws" and "technical errors" were excluded, the IR further increased significantly. Therefore, these parameters should be recorded in order to standardized the HBKT, but not be included in the statistical analysis. There are discrete adaptation and learning effects. For this reason, it is essential to familiarise trainers and players with the HBKT test procedure before the first measurement. Otherwise training effects can be easily overrated. Moreover, the test concept of HBKT can be used as a blueprint for the development of sport-specific tests in other team sports (e. g., soccer, basketball). For example, we generated a complex soccer-specific field test 1 based on the HBKT.

Aim: To assess the histopathological background of enhancement mechanisms in dynamic MR mammography studies. Methods: The dynamic MR mammography (MRM) examinations were done with a 1.5T MR imager (Magnetom Vision, Siemens) using a double breast coil and a coronal FLASH-3D sequence. Enhancement data were acquired during 9 minutes post contrast medium injection (Gd-DTPA, 0.2 mmol/kg). Acquisition time was 87 sec/slab. Early enhancement at the first post contrast measurement (E 1 ) and slope of wash-out (SE 2-L ) were calculated. In immunohistology, proliferation was assessed by the monoclonal antibody Ki 67, capillaries were stained by a CD 31 antibody. Of a total of 48 operated patients, 58 lesions and 46 surrounding tissues were evaluated. Results: Cellularity, capillary density and proliferation showed statistically significant correlations with E 1 (p < 0.01). In multiple regression analysis, E 1 was significantly associated only with high cellularity (p = 0.002) and the combination of high cellularity and high microvessel density (p = 0.002); a negative slope of wash out was significantly associated only with malignant histology (p = 0.027). Conclusions: Our findings indicate a direct influence of cellularity and microvessel density on early enhancement. The expression of the proliferation marker Ki 67 was not an independent predictor for contrast enhancement.

At the time of primary therapy (surgery, systemic chemotherapy and/or radiation), disseminated tumor cells in the bone marrow can be found in almost one-third of patients with cancer of the breast, ovary, esophagus, stomach, colon, and other solid tumors. Whereas the prognostic impact of the mere presence of these cells is still a matter of debate, it has been shown that expression of tumor-associated antigens in disseminated tumor cells is linked to more aggressive disease. Therefore, further characterization of disseminated tumor cells at the protein and gene level has become increasingly important. To date, the most common detection method for disseminated tumor cells in the bone marrow is an immunocytochemical approach using cytokeratin-directed antibodies for detection of epithelial cells and the APAAP system for their visualization. We have established a new double immunofluorescence technique enabling simultaneous detection, phenotyping, and antigen quantification of disseminated tumor cells. Mononuclear cells from bone marrow are enriched by Ficoll gradient centrifugation and cytospins are prepared. Double immunofluorescence is performed using antibodies against cytokeratins 8/18/19 (mAb A45B/B3) and the uPA receptor CD87 (pAb HU277). CD87 expression is recorded by confocal laser scanning microscopy (CLSM) using fluorescence labeled latex beads as the reference; staining intensities of all the scans are then summed and quantified (extended focus). This protocol, originally designed for disseminated tumor cells in bone marrow, can also be applied to disseminated tumor cells in blood, to leukapheresis cells or to cells present in malignant ascites or other malignant effusions. The tumor cells detected may be used for gene and mRNA analyses. Furthermore, disseminated tumor cells also represent interesting targets for clinical studies on patient prognosis or prediction of therapy response as well as for specific tumor-biological therapies.

We present a comprehensive study of the optimum operating regime in a gain-switched Cr:forsterite laser at a repetition frequency of 1 kHz with special attention to temperature-dependent and parasitic absorption effects and proper resonator design. On the basis of the results achieved, me demonstrate highly efficient (13% extraction efficiency) operation of a femtosecond regenerative amplifier based on Cr:forsterite and operating near room temperature with a novel BBO Pockels cell that is highly resistant to optical damage. Chirped pulse amplification raises the pulse energy to 355 /spl mu/J in /spl ap/30 cavity round trips which corresponds to an amplification factor of /spl ap/5.5/spl times/10/sup 5/. The nearly transform limited 200-/spl mu/J 135-fs compressed pulses near 1.25 /spl mu/m have a peak power of /spl ap/1.5 GW. Frequency doubling with 52% conversion efficiency in LBO produces femtosecond pulses of 104-/spl mu/J energy in the visible near 625 nm.

In this paper we report the first molecular dynamics study combining fast field-cycling and conven-tional NMR techniques in a thermotropic liquid crystal of discotic molecules exhibiting an ordered columnar hexagonal mesophase. Using the association of these techniques we obtained proton T1 data over a very large domain of Larmor frequencies (ω/2π from 500 Hz to 85 MHz). The proton spin-lattice relaxation results were analysed considering the structure of the mesophase and the types of movements which are expected to influence significantly the relaxation rate, namely local molecu-lar rotational reorientations, inter-columnar self-diffusion and collective movements corresponding to bending and compression of the columns. We verified that these mechanisms dominate the relaxation respectively for high, medium and low Larmor frequencies.

Larmor frequency dependent NMR studies of dipolar order relaxation in liquid crystals have seldom been tried in the past. Using conventional static magnetic field techniques, the experiment cannot be extended to the low Larmor frequency (νL) regime due to limitations in the signal-to-noise ratio of the dipolar echo. In this work, we present an experimental study of the dipolar relaxation time in the frequency range 103–7×107 Hz in nematic thermotropic liquid crystals. To extend the study to such low frequencies, we used the Jeener–Broekaert pulse sequence combined with fast field-cycling NMR technique. For frequencies higher than 105 Hz, the dipolar relaxation time T1D(νL) follows the νL1/2-law that is characteristic of order fluctuations of the director (OFD) in nematics. In contrast, the Zeeman relaxation is driven by faster and less correlated motions, specially in the MHz frequency range. The relaxation of dipolar energy was measured to be remarkably faster than the one predicted by the usual semiclas...

We investigate the NMR relaxation of solvent nuclei in non viscous paramagnetic solutions, in the case where the electronic spin of the paramagnetic species is submitted to an internal hyperfine fi...

Nonthermal in vitro ablation of bovine neural tis- sue by using laser-induced optical breakdown generated by ultrashort laser pulses, with durations from 100 fs to 35 ps and pulse energies of up to 165mJ, has been investigated. The experiments were performed at wavelengths ranging from 630 to 1053 nm by using a femtosecond Ti:Sapphire laser, a femtosecond dye laser, and a picosecond Nd:YLF laser sys- tem. Tissue ablations have been achieved by focusing the laser beam on the surface of the tissue, to a spot diameter of 5- 20mm, resulting in the generation of a microplasma. Laser pulses from the Ti:Sapphire laser with 140 fs duration showed a two times higher efficiency of ablation than the longer 30 ps pulses from a Nd:YLF laser with an identical pulse energy. At pulse energies of 140mJ, single pass excisions deeper than 200mm were generated by the 140 fs pulses. In addition, the fluence at threshold of the ablation was found to be reduced for shorter pulse durations. For 3p slaser pulses at 630 nm, we measured the fluence at threshold to be about 5: 3J =cm 2 ; for 100 fs pulses from the same laser the experimental thresh- old was at 1: 5J =cm 2 . Histopathological examinations and scanning electron micrographs confirm the high quality of the excisions. No sign of significant thermal damage was ob- served.

The frequency dependence of the longitudinal proton spin relaxation time T1 was measured by field-cycling and standard NMR techniques at different temperatures in the liquid crystalline lamellar phases of bilayer systems, composed of lipids, nonionic surfactants, and lipid-surfactant mixtures. We show by our data analysis, comparing various motional models such as layer undulations (LUs) and relaxation by translational diffusion mediated reorientations (TR), that collective layer undulations with their typical T1~ν behaviour determine the low frequency T1 dispersion in both unoriented and glass plate-oriented bilayer systems. The angular dependence of the T1 dispersion for the oriented bilayer system supports these findings and provides a more critical analysis of the two dimensional self-diffusion than in unoriented samples. The evaluated fitting parameters of the LU model allows, together with the measured second moment of the proton NMR signal for the lipid, calculation of the bending rigidity ϰc for these bilayers at different levels of hydration. The obtained values of ϰc turn out to be too large compared with the literature. However, using recent LU models (B. Halle) which include the obvious couplings between neighbouring bilayers at low Larmor frequencies, the corrected ϰc of the fully hydrated membrane systems are comparable to those obtained from the standard videooptical experiments. Therefore proton spin relaxation measure-ments at low Larmor frequencies with the field-cycling technique are a suitable means to determine the bending rigidity ϰc of model membrane systems at low hydrations and of systems containing surfactants.

We report the first study of1nolecular dynaInics in a TGBA Inesophase, by Ineans of proton NMR relaxation, in a liquid crystal coInpound that exhibits TGBA and Sl Inesophases. The relaxation dispersion detected in the S( phase is siInilar to those observed in previous studies on this phase of other compounds, using the saIne experimental technique. The Inolecular dynaInics in the TGBA phase is clearly different froIn the one detected in conventional SA Inesophases of chiral Inolecules. In fact, for low Larlnor frequencies the Ti values increase on decreasing the teInperature, while for higher frequencies an inverse behaviour is detected. Furthermore, the slope of Ti over the phase transition TGBA Sl depends on the frequency. An additional relaxation Inechanisln arising froIn the particular structure of the TGBA phase is introduced in this work to describe the observed differences.