Metrópolis de Fritz Lang

Abstract not availabl

Effects of different deep freezing and thawing procedures on the developmental capacity of bovine embryos

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Regional depth-specific subchondral bone density measures in osteoarthritic and normal distal femora: in vivo precision and preliminary comparisons

Knee osteoarthritis (OA) is a degenerative disease which affects the cartilage and underlying bone of afflicted joints. OA can be diagnosed by clinical symptoms such as joint pain, stiffness and swelling or radiographically according to the presence of key structural changes associated with the disease. The investigation of subchondral bone is a growing topic of interest in the study of OA, though its exact relationship with disease initiation and progression is currently not well understood. Previous studies have investigated subchondral bone’s role in OA at the proximal tibia and patella; however there is a paucity of research at the distal femur. Additionally, many of the existing strategies to study subchondral bone in OA have relied on time-consuming manual techniques, limiting their applicability in studies with large sample sizes. This highlights a need for the development of automated techniques which assess subchondral bone at the distal femur. The primary goal of this research was to develop an automated workflow capable of precisely assessing regional density measures at the distal femur to differentiate between OA and normal subjects. This resulted in the following objectives: 1) Develop an automated workflow for assessing regional density measures at the distal femur; 2) determine precision errors of the acquired density measures; and 3) compare distal femoral density measures between individuals with and without knee OA. Following the development of an automated workflow, in vivo precision (assessed via root mean square coefficients of variation, CV%RMS) at the distal femur was assessed and ranged from 1.6% to 3.6%. These results are consistent with the in vivo precision errors found at the proximal tibia and patella, indicating they are suitable for investigating differences between OA and normal distal femora. For the comparison analysis, mean regional density measures were not found to differ significantly between normal and OA distal femora; however, peak density clusters at depths of 2.5-5mm were found to be ~16% lower in OA distal femora. Thesis results indicate that suitable precision can be obtained at the distal femur with automated methods. Results also suggest that subchondral density patterns may differ in OA and normal distal femora in complex ways, not necessarily detectable via regional analyses alone

Dietary and serum tyrosine, white matter microstructure and inter-individual variability in executive functions in overweight adults: Relation to sex/gender and age

Tyrosine (tyr), the precursor of the neurotransmitter dopamine, is known to modulate cognitive functions including executive attention. Tyr supplementation is suggested to influence dopamine-modulated cognitive performance. However, results are inconclusive regarding the presence or strength and also the direction of the association between tyr and cognitive function. This pre-registered cross-sectional analysis investigates whether diet-associated serum tyr relates to executive attention performance, and whether this relationship is moderated by differences in white matter microstructure. 59 healthy, overweight, young to middle-aged adults (20 female, 28.3 ± 6.6 years, BMI: 27.3 ± 1.5 kg/m2) drawn from a longitudinal study reported dietary habits, donated blood and completed diffusion-weighted brain magnetic resonance imaging and the attention network test. Main analyses were performed using linear regressions and non-parametric voxel-wise inference testing. Confirmatory analyses did neither support an association between dietary and serum tyr nor a relationship between relative serum tyr/large neutral amino acids (LNAA) levels or white matter microstructure and executive attention performance. However, exploratory analyses revealed higher tyr intake, higher serum tyr and better executive attention performance in the male sex/gender group. In addition, older age was associated with higher dietary tyr intake and lower fractional anisotropy in a widespread cluster across the brain. Finally, a positive association between relative serum tyr/LNAA and executive attention performance was found in the male sex/gender group when accounting for age effects. Our analysis advances the field of dopamine-modulated cognitive functions by revealing sex/gender and age differences which might be diet-related. Longitudinal or intervention studies and larger sample sizes are needed to provide more reliable evidence for links between tyr and executive attention

Qualität von eiern und embryonen superovulierter kühe

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Mood Disorders Are Glial Disorders: Evidence from In Vivo Studies

It has recently been suggested that mood disorders can be characterized by glial pathology as indicated by histopathological postmortem findings. Here, we review studies investigating the glial marker S100B in serum of patients with mood disorders. This protein might act as a growth and differentiation factor. It is located in, and may actively be released by, astro- and oligodendrocytes. Studies consistently show that S100B is elevated in mood disorders; more strongly in major depressive than bipolar disorder. Successful antidepressive treatment reduces S100B in major depression whereas there is no evidence of treatment effects in mania. In contrast to the glial marker S100B, the neuronal marker protein neuron-specific enolase is unaltered. By indicating glial alterations without neuronal changes, serum S100B studies confirm specific glial pathology in mood disorders in vivo. S100B can be regarded as a potential diagnostic biomarker for mood disorders and as a biomarker for successful antidepressive treatment

Mode locking using a type II multiple-quantum-well structure as a fast saturable absorber

We demonstrate the application of a type II AlGal-.xAs/AlAs multiple quantum well as a fast saturable absorber in a hybridly mode-locked dye laser. Type II multiple quantum wells are promising for this application because of the fast recovery of the saturated absorption with picosecond or even subpicosecond time constants. We obtain almost transform-limited pulses as short as 0.9 psec for a type II sample with a recovery time of 2.3 psec. Passive or hybrid (active-passive) mode locking requires saturable absorbers with recovery times Ta that are short in comparison with the recovery time rg of the saturable gain.1 2 Generally, suitable dyes are used in passive or hybrid mode-locked dye laser systems, such as DODCI in combination with Rhodamine 6G in the colliding-pulse mode-locked laser. Semiconductor materials are also attractive for saturable absorbers because of the large optical nonlinearities that can be obtained, particularly in quantum-well structures. 3 However, in high-quality materials the recovery time of the saturated absorption is quite slow owing to the long carrier recombination time constants, which are in the nanosecond range for materials such as GaAs or InP, related alloys, and quantumwell structures. Thus applications as saturable absorbers for mode locking at high repetition rates as well as applications in optical processing, where fast switching at high bit rates is required, are not always possible. To overcome this the recombination lifetime can be reduced by creation of defects, e.g., by ion bombardment, which results in an increased concentration of nonradiative centers. 2 In fact, mode locking of a GaAs semiconductor laser at a repetition rate of 2 GHz with a proton-bombarded quantum-well saturable absorber has been reported, and pulses of 1.6 psec have been achieved. 2 Much shorter pulses, down to 120 fsec, have been obtained by passive mode locking of color-center lasers with HgCdTe multiple-quantum-well (MQW) saturable absorbers. 7 The nonlinearity responsible for saturable absorption in semiconductors is due to exciton bleaching. In semiconductor quantum wells like GaAs/AlGaAs electronic states are confined in one dimension, which results in an increase of exciton binding energy and oscillator strength compared with that of bulk material. In the normal, so-called type I structures, the upper valence band and lowest conduction band states are spatially located in the material with the smaller band gap, i.e., electrons and holes are confined in the same slab, e.g., in GaAs if the type I GaAs/AlGaAs structures are considered. The recovery time of the optical nonlinearity in these type I structures is generally determined by the recombination lifetime, which is of the order of 1 nsec at room temperature. Type II structures, in contrast, are characterized by a spatial separation within the different slabs of the quantumwell structure of the upper valence band and the lowest conduction band states. The lowest-lying electronic conduction band states of type II AlxGal-,As/ AlAs MQW structures originate from X-conduction band states of the indirect-gap AlAs material 8 and thus are basically confined in the AlAs barrier material. The upper valence band states with r symmetry, however, are confined to the AlGaAs well. The absorption spectrum in these type II samples is governed by the direct optical transitions at higher energies, involving the r valence band and the X-conduction band states of Al.Gal~-As, since the oscillator strength for the indirect r-X transition is smaller by orders of magnitude. 8 Optical pump and probe experiments at the resonance peak of the lowest-lying direct heavy-hole excitonic transition reveal a partial recovery of the bleached absorption with a picosecond or even subpicosecond time constant 7 that is much 0146-9592/91/040241-03$5.00/

Contact force sensing in ablation of ventricular arrhythmias using a 56-hole open-irrigation catheter: a propensity-matched analysis.

PURPOSE: The effect of adding contact force (CF) sensing to 56-hole tip irrigation in ventricular arrhythmia (VA) ablation has not been previously studied. We aimed to compare outcomes with and without CF sensing in VA ablation using a 56-hole radiofrequency (RF) catheter. METHODS: A total of 164 patients who underwent first-time VA ablation using Thermocool SmartTouch Surround Flow (TC-STSF) catheter (Biosense-Webster, Diamond Bar, CA, USA) were propensity-matched in a 1:1 fashion to 164 patients who had first-time ablation using Thermocool Surround Flow (TC-SF) catheter. Patients were matched for age, gender, cardiac aetiology, ejection fraction and approach. Acute success, complications and long-term follow-up were compared. RESULTS: There was no difference between procedures utilising either TC-SF or TC-STSF in acute success (TC-SF: 134/164 (82%), TC-STSF: 141/164 (86%), p = 0.3), complications (TC-SF: 11/164 (6.7%), TC-STSF: 11/164 (6.7%), p = 1.0) or VA-free survival (TC-SF: mean arrhythmia-free survival time = 5.9 years, 95% CI = 5.4-6.4, TC-STSF: mean = 3.2 years, 95% CI = 3-3.5, log-rank p = 0.74). Fluoroscopy time was longer in normal hearts with TC-SF (19 min, IQR: 14-30) than TC-STSF (14 min, IQR: 8-25; p = 0.04). CONCLUSION: Both TC-SF and TC-STSF catheters are safe and effective in treating VAs. The use of CF sensing catheters did not improve safety or acute and long-term outcomes, but reduced fluoroscopy time in normal heart VA