Raman spectroscopy of thermo- and laser-induced transformations of gouache paint layer of copper phthalocyanine blue.

Methods to control polymorphic modifications of phthalocyanines using optical (laser) radiation and possible photoinduced transformations of polymorphs are of practical interest in problems of identification and attribution of paintings, laser (micro)sampling, and the development of phthalocyanine structures for technical applications in optics, optoelectronics, and medicine. In this work, we compare the thermal and laser-induced changes of a gouache paint layer based on copper phthalocyanine (CuPc) PB15. The thermally induced color changes of the paint layer are quantified using the CIE Lab D65/10 color space. (Nano)rods formed in the paint layer when the sample is heated to 450°C at normal pressure without humidity control are studied using absorption spectroscopy, Raman microspectroscopy, and scanning electron microscopy. It is shown that the formation of (nano)rods is related to the αâ†’ß polymorph transition of CuPc. Low-frequency markers of the CuPc ß-polymorph are revealed in the Raman spectra. For the sample containing (nano)rods, the a* color coordinate substantially increases (by about 30 units), whereas the L* and b* coordinates remain almost unchanged. Irradiation with a single nanosecond laser pulse at a wavelength of 532 nm leads to the laser ablation of the paint layer at fluences exceeding a threshold level of about 3 J/cm2. Irradiation at fluences of greater than 0.5 J/cm2, but lower than the ablation threshold leads to color change of the paint layer due to the α→ε transition of CuPc. Similar transformations are observed at the periphery of and inside ablation crater.

Sensor Noise in LISA Pathfinder: In-Flight Performance of the Optical Test Mass Readout.

We report on the first subpicometer interferometer flown in space. It was part of ESA's Laser Interferometer Space Antenna (LISA) Pathfinder mission and performed the fundamental measurement of the positional and angular motion of two free-falling test masses. The interferometer worked immediately, stably, and reliably from switch on until the end of the mission with exceptionally low residual noise of 32.0_{-1.7}^{+2.4} fm/sqrt[Hz], significantly better than required. We present an upper limit for the sensor performance at millihertz frequencies and a model for the measured sensitivity above 200 mHz.

Hormetic modulation of angiogenic factors by exercise-induced mechanical and metabolic stress in human skeletal muscle.

This study used an integrative experimental model in humans to investigate whether muscle angiogenic factors are differentially modulated by exercise stimuli eliciting different degrees of mechanical and metabolic stress. In a randomized crossover design, 12 men performed two low-volume high-intensity exercise regimens, including short sprint intervals (SSI) or long sprint intervals (LSI) inducing pronounced mechanical/metabolic stress, and a high-volume moderate-intensity continuous exercise protocol (MIC) inducing mild but prolonged mechanical/metabolic stress. Gene and protein expression of angiogenic factors was determined in vastus lateralis muscle samples obtained before and after exercise. Exercise upregulated muscle VEGF mRNA to a greater extent in LSI and MIC compared with SSI. Analysis of angiogenic factors sensitive to shear stress revealed more marked exercise-induced VEGF receptor 2 (VEGF-R2) mRNA responses in MIC than SSI, as well as greater platelet endothelial cell adhesion molecule (PECAM-1) and endothelial nitric oxide synthase (eNOS) mRNA responses in LSI than SSI. No apparent exercise-induced phosphorylation of shear stress-sensory proteins VEGF-R2Tyr1175, PECAM-1Tyr713, and eNOSSer1177 was observed despite robust elevations in femoral artery shear stress. Exercise evoked greater mRNA responses of the mechanical stretch sensor matrix metalloproteinase-9 (MMP9) in SSI than MIC. Exercise-induced mRNA responses of the metabolic stress sensor hypoxia-inducible factor-1α (HIF-1α) were more profound in LSI than SSI. These results suggest that low-volume high-intensity exercise transcriptionally activates angiogenic factors in a mechanical/metabolic stress-dependent manner. Furthermore, the angiogenic potency of low-volume high-intensity exercise appears similar to that of high-volume moderate-intensity exercise, but only on condition of eliciting severe mechanical/metabolic stress. We conclude that the angiogenic stimulus produced by exercise depends on both magnitude and protraction of myocellular homeostatic perturbations.NEW & NOTEWORTHY Skeletal muscle capillary growth is orchestrated by angiogenic factors sensitive to mechanical and metabolic signals. In this study, we employed an integrative exercise model to synergistically target, yet to different extents and for different durations, the mechanical and metabolic components of muscle activity that promote angiogenesis. Our results suggest that the magnitude of the myocellular perturbations incurred during exercise determines the amplitude of the angiogenic molecular signals, implying hormetic modulation of skeletal muscle angiogenesis by exercise-induced mechanical and metabolic stress.

Characterization of Putative Virulence Factors of Pseudomonas aeruginosa Strain RBS Isolated from a Saltern, Tunisia: Effect of Metal Ion Cofactors on the Structure and the Activity of LasB.

Pseudomonas aeruginosa is a ubiquitous Gram-negative bacterium able to survive in diverse environments such as soil, plants, freshwater, and seawater. P. aeruginosa can be an opportunistic pathogen to humans when their immune system is deficient. Its pathogenicity may be linked to the production of virulence factors. We isolated P. aeruginosa strain RBS from the saltern of Sfax in Tunisia. In this study, we characterized the halotolerance, antibiotic susceptibility, and some virulence factors of strain RBS. High NaCl concentrations inhibited growth and motility. However, biofilm formation was enhanced to protect bacteria against salt stress. Among the 18 antibiotics tested, quinolones and tetracycline showed a significant inhibitory effect on growth, motility, and biofilm formation of strain RBS. ß-Lactams, however, did not have any inhibitory effect on neither bacterial growth nor motility. In some cases, resistance was due, in part, to biofilm formation. We also showed that RBS produces two proteases, LasB and AprA, which have been shown to be implicated in host infection. LasB was further characterized to study the role of metal ions in enzyme stability. It possesses two distinct metal ion-binding sites coordinating a calcium and a zinc ion. The effect of metal ion chelation was evaluated as well as substitutions of residues involved in metal ion binding. Impairing metal ion binding of LasB led to a loss of activity and a sharp decrease of stability. Our findings suggest that the binding of both metal ions is interdependent as the two metal ions' binding sites are linked via a hydrogen bond network.

Neural sex steroids and hippocampal synaptic plasticity.

It was a widely held belief that sex steroids, namely testosterone and 17ß-estradiol (E2) of gonadal origin, control synaptic plasticity in the hippocampus. A new paradigm emerged when it was shown that these sex steroids are synthesized in the hippocampus. The inhibition of sex steroids in the hippocampus impairs synaptic plasticity sex-dependently in this region of the brain. In gonadectomized animals and in hippocampal cultures, inhibition of estradiol synthesis in female animals and in cultures from female animals, and inhibition of dihydrotestosterone synthesis in male animals and in cultures of male animals, cause synapse loss and impair LTP in the hippocampus, but not vice versa. Since the hippocampal cultures originated from perinatal animals, and due to the similarity of in vivo and in vitro findings, it appears that hippocampal neurons are differentiated in a sex-specific manner during the perinatal period when sexual imprinting takes place.

Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder.

We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave detector. Employing a combination of charge control and electric-field compensation, we show that the level of charge-induced acceleration noise on a single TM can be maintained at a level close to 1.0 fm s^{-2} Hz^{-1/2} across the 0.1-100 mHz frequency band that is crucial to an observatory such as the Laser Interferometer Space Antenna (LISA). Using dedicated measurements that detect these effects in the differential acceleration between the two test masses, we resolve the stochastic nature of the TM charge buildup due to interplanetary cosmic rays and the TM charge-to-force coupling through stray electric fields in the sensor. All our measurements are in good agreement with predictions based on a relatively simple electrostatic model of the LISA Pathfinder instrument.

Photoinduced formation of thiols in human hair.

Raman, scanning electron, and optical microscopy of hair and spectrophotometry of soluble hair proteins are used to study the effect of UV-vis radiation on white hair. The samples of a healthy subject are irradiated using a mercury lamp and compared with non-irradiated (control) hair. The cuticle damage with partial exfoliation is revealed with the aid of SEM and optical microscopy of semifine sections. Gel filtration chromatography shows that the molecular weight of soluble proteins ranges from 5 to 7kDa. Absorption spectroscopy proves an increase in amount of thiols in a heavier fraction of the soluble proteins of irradiated samples under study. Raman data indicate a decrease in the amount of SS and CS bonds in cystines and an increase in the amount of SH bonds due to irradiation. Such changes are more pronounced in peripheral regions of hair. Conformational changes of hair keratins presumably related to the cleavage of disulfide bonds, follow from variations in amide I and low-frequency Raman bands. An increase in the content of thiols in proteins revealed by both photometric data on soluble proteins and Raman microspectroscopy of hair cuts can be used to develop a protocol of the analysis of photoinduced hair modification.

Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results.

We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2±0.1 fm s^{-2}/sqrt[Hz], or (0.54±0.01)×10^{-15} g/sqrt[Hz], with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8±0.3) fm/sqrt[Hz], about 2 orders of magnitude better than requirements. At f≤0.5 mHz we observe a low-frequency tail that stays below 12 fm s^{-2}/sqrt[Hz] down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.

[Gender and the effects of steroid hormones in the central nervous system]. / Geschlecht und Effekte von Steroidhormonen im Zentralnervensystem (ZNS).

Degenerative diseases of the central nervous system, the incidence and prevalence of which vary between men and women, often manifest in the hippocampus. Neurosteroids are hormones that are synthesized in the CNS, and it is here that they exert their influence. Estrogen and testosterone are examples of neurosteroid hormones. In the hippocampus, an area of the brain closely associated with learning and memory, the local synthesis of estrogen in females, but not in males, is essential for the plasticity and stability of the synapses. The inhibition of estrogen synthesis in the female hippocampus causes a reduction in long-term potentiation (LTP), an electrophysiological parameter of learning and memory, thus resulting in a significant loss of synapses. In light of this, the fact that estrogen has been attributed with many neuroprotective functions in degenerative diseases of the CNS suggests that therapeutic concepts involving the use of estrogen are possibly only effective in women, but not in men. These findings similarly provide a basis for explaining the gender dimorphism that has been found in certain degenerative illnesses of the CNS.

Hippocampal estradiol synthesis and its significance for hippocampal synaptic stability in male and female animals.

Increasing evidence points to an essential role played by neuron-derived neurosteroids, such as estrogen, on synaptic connectivity in the hippocampus. Inhibition of local estradiol synthesis results in synapse loss specifically in females, but not in males. Synapse loss in females, after inhibition of estradiol synthesis in hippocampal neurons, appears to result from impairment of long-term potentiation (LTP) and dephosphorylation of cofilin, and thereby the destabilization of postsynaptic dendritic spines. Such clear-cut effects were not seen in males. Cognitive deficits after inhibition of aromatase, the final enzyme of estrogen synthesis, have been seen in women, but not in men. Altogether, the data demonstrate distinct differences between genders in neurosteroid-induced synaptic stability.

Oestradiol-induced synapse formation in the female hippocampus: roles of oestrogen receptor subtypes.

During the oestrus cycle, varying spine synapse density correlates positively with varying local synthesis of oestradiol in the hippocampus. In this context, the roles of the oestrogen receptor (ER) subtypes ERα and ß are not fully understood. In the present study, we used neonatal hippocampal slice cultures from female rats because these cultures synthesise oestradiol and express both receptor subtypes, and inhibition of oestradiol synthesis in these cultures results in spine synapse loss. Using electron microscopy, we tested the effects on spine synapse density in response to agonists of both ERα and ERß. Application of agonists to the cultures had no effect. After inhibition of oestradiol synthesis, however, agonists of ERα induced spine synapse formation, whereas ERß agonists led to a reduction in spine synapse density in the CA1 region of these cultures. Consistently, up-regulation of ERß in the hippocampus of adult female aromatase-deficient mice is paralleled by hippocampus-specific spine synapse loss in this mutant. Finally, we found an increase in spine synapses in the adult female ERß knockout mouse, but no effect in the adult female ERα knockout mouse. Our data suggest antagonistic roles of ERß and ERα in spine synapse formation in the female hippocampus, which may contribute to oestrus cyclicity of spine synapse density in the hippocampus.

Impact of carbohydrate supplementation during endurance training on glycogen storage and performance.

AIM: Glucose ingestion may improve exercise endurance, but it apparently also influences the transcription rate of several metabolic genes and it alters muscle metabolism during an acute exercise bout. Therefore, we investigated how chronic training responses are affected by glucose ingestion. METHODS: In previously untrained males performance and various muscular adaptations were evaluated before and after 8 weeks of supervised endurance training conducted either with (n = 8; CHO group) or without (n = 7; placebo) glucose supplementation. RESULTS: The two groups achieved similar improvements in maximal oxygen uptake and peak power output during incremental cycling (both parameters elevated by 17% on average) and both groups lost approximately 3 kg of fat mass during the 8 weeks of training. An equal reduction in respiratory exchange ratio (0.02 units) during submaximal exercise was observed in both groups. Beta-hydroxyacyl-CoA-dehydrogenase activity was increased in both groups, however, to a larger extent in the placebo group (45 +/- 11%) than CHO (23 +/- 9%, P < 0.05). GLUT-4 protein expression increased by 74 +/- 14% in the placebo group and 45 +/- 14% in CHO (both P < 0.05), while resting muscle glycogen increased (P < 0.05) to a larger extent in the placebo group (96 +/- 4%) than CHO (33 +/- 2%). CONCLUSION: These results show that carbohydrate supplementation consumed during exercise training influences various muscular training adaptations, but improvements in cardiorespiratory fitness and reductions in fat mass are not affected.

Potential role of TBC1D4 in enhanced post-exercise insulin action in human skeletal muscle.

AIMS/HYPOTHESIS: TBC1 domain family, member 4 (TBC1D4; also known as AS160) is a cellular signalling intermediate to glucose transport regulated by insulin-dependent and -independent mechanisms. Skeletal muscle insulin sensitivity is increased after acute exercise by an unknown mechanism that does not involve modulation at proximal insulin signalling intermediates. We hypothesised that signalling through TBC1D4 is involved in this effect of exercise as it is a common signalling element for insulin and exercise. METHODS: Insulin-regulated glucose metabolism was evaluated in 12 healthy moderately trained young men 4 h after one-legged exercise at basal and during a euglycaemic-hyperinsulinaemic clamp. Vastus lateralis biopsies were taken before and immediately after the clamp. RESULTS: Insulin stimulation increased glucose uptake in both legs, with greater effects (approximately 80%, p < 0.01) in the previously exercised leg. TBC1D4 phosphorylation, assessed using the phospho-AKT (protein kinase B)substrate antibody and phospho- and site-specific antibodies targeting six phosphorylation sites on TBC1D4, increased at similar degrees to insulin stimulation in the previously exercised and rested legs (p < 0.01). However, TBC1D4 phosphorylation on Ser-318, Ser-341, Ser-588 and Ser-751 was higher in the previously exercised leg, both in the absence and in the presence of insulin (p < 0.01; Ser-588, p = 0.09; observed power = 0.39). 14-3-3 binding capacity for TBC1D4 increased equally (p < 0.01) in both legs during insulin stimulation. CONCLUSION/INTERPRETATION: We provide evidence for site-specific phosphorylation of TBC1D4 in human skeletal muscle in response to physiological hyperinsulinaemia. The data support the idea that TBC1D4 is a nexus for insulin- and exercise-responsive signals that may mediate increased insulin action after exercise.

First Report of Summer Patch of Kentucky Bluegrass Caused by Magnaporthe poae in Colorado.

The ectotrophic, root-infecting fungus Magnaporthe poae is the cause of summer patch of Kentucky bluegrass (Poa pratensis). The disease is widely distributed in the mid-Atlantic Region of the United States and west to central Nebraska and Kansas (2). It also has been found in certain locations of Washington and California (2) but has not been confirmed in the Rocky Mountain Region. In August 2005 and 2006, tan patches and rings of dead turf ranging from 10 to 30 cm in diameter were observed in Kentucky bluegrass swards in Grand Junction and Greeley, CO, respectively. The sites, separated by approximately 360 km, are located west and east of the Continental Divide. A network of ectotrophic hyphae were observed on diseased root segments collected from both sites. A fungus morphologically similar to M. poae (2) was consistently isolated from these segments. DNA was extracted from mycelium of one isolate from each location and amplified by PCR with the M. poae species-specific primers MP1 and MP2 (1). A 453-bp DNA fragment was consistently amplified from DNA of both isolates, diagnostic of M. poae. To our knowledge, this is the first report of summer patch in Colorado and indicates that M. poae may be widely distributed in the central Rocky Mountain Region. References: (1) T. E. Bunting et al. Phytopathology 86:398, 1996. (2) B. B. Clarke and A. B. Gould, eds. Turfgrass Patch Diseases Caused by Ectotrophic Root-Infecting Fungi. The American Phytopathological Society, St. Paul, MN, 1993.

Optimization of the rolling-circle filter for Raman background subtraction.

A procedure is proposed to optimize a high-pass filter enabling one to subtract the broadband background signals inherent in Raman spectra. A spectral approach is used to analyze the characteristics of the filter and the distortions in the processed spectra. Examples of the processing of real spectra are presented.

Measurement of hematological, clinical chemistry, and infection parameters from hirudinized blood collected in universal blood sampling tubes.

Hirudin, the anticoagulatory polypeptide of the leech Hirudo medicinalis, strongly inhibits thrombus formation by specifically interacting with thrombin. For diagnostic purposes, hirudin should be superior to other anticlotting compounds because it only minimally alters the mineral, protein, and cellular blood constituents. To test this hypothesis, hirudinized and routinely processed venous blood from 80 healthy volunteers and patients was subjected to a variety of automated blood tests. A strong correlation was found between the results of automated complete blood counts obtained from K(2)-ethylenediaminetetraacetic acid (EDTA) anticoagulated and hirudinized blood (1000 antithrombin units [ATU] hirudin/ml). In addition, clinical chemistry and serological infection parameters (asparlat amintransferase [ASAT], lactate dehydrogenase [LDH], sodium, and so on, and antibodies against hepatitis B and C and human immunodeficiency virus [HIV]1/2, respectively) correlated well when measured in serum as compared with hirudinized plasma. Contrary to single clotting factors, global coagulation parameters (activated partial thromboplastin time [aPTT], prothrombin time [PT]) could not be measured in hirudinized blood. Recombinant hirudin neither interfered with immunophenotyping of mononuclear cells using FACScan analysis, nor did it alter the detection of Wilms' tumor gene expression by RT-PCR technology even at high doses (5000 ATU hirudin). Thus, a hirudin-containing blood sampling tube can be designed as a universal blood sampling tube (UBT) for testing the majority of diagnostic blood parameters.

Neonatal screening for galactosemia by quantitative analysis of hexose monophosphates using tandem mass spectrometry: a retrospective study.

BACKGROUND: Classic galactosemia (OMIM 230400) is an inherited disorder in the metabolism of galactose caused by deficiency of the enzyme galactose 1-phosphate uridyl transferase (EC 2.7.7.12). Galactosemia leads to accumulation of galactose and galactose 1-phosphate (gal-1-P) in blood and tissues and, if untreated, produces neonatal death or severe mental retardation, cirrhosis of the liver, and cataracts. Hence, the disorder is included in many neonatal screening programs. METHODS: We retrospectively analyzed filter-paper blood samples obtained 4-8 days postpartum for routine neonatal screening from 12 galactosemia patients and 2055 random controls. Total hexose monophosphates (HMPs) were used as a marker of gal-1-P and were assayed by negative-ion mode electrospray tandem mass spectrometry (tandem MS) with settings biased toward gal-1-P detection. The predominant precursor/product ion pair m/z 259/79 was used to quantify total HMPs by external standardization. RESULTS: Linear calibration curves were obtained in the range 0-8 mmol/L gal-1-P. The detection limit was 0.1 mmol/L HMP, and total CVs ranged from 13% at the detection limit to <8% at >1 mmol/L HMP. The method was in agreement with an alkaline phosphatase-galactose dehydrogenase method. All samples from galactosemia patients contained increased HMP concentrations (range for patients, 2.6-5.2 mmol/L; range for reference group, <0.10-0.94 mmol/L). The diagnostic sensitivity and specificity were 100% at a cutoff of 1.2 mmol/L HMP. A Duarte/classic galactosemia compound heterozygous sample could be discriminated clearly from both patient and reference samples. CONCLUSION: Quantitative analysis of HMPs by tandem MS can be used in laboratory investigations of galactosemia.

The use of hirudin as universal anticoagulant in haematology, clinical chemistry and blood grouping.

Undesirable interactions between anticoagulants and diagnostic test kit procedures so far have prevented the development of a single uniform blood sampling tube. Contrary to K2-EDTA, heparin and other anticoagulants, hirudin only minimally alters blood cells and dissolved blood constituents, thus qualifying as a universal anticoagulant for diagnostic purposes. Automated complete blood counts, automated analyses of clinical chemistry analytes and immunohaematology were performed from hirudinised and routinely processed blood obtained from healthy volunteers (n=35) and hospitalised patients (n=45). Hirudin (400 ATU/ml blood) sufficiently anticoagulated blood for diagnostic purposes. The measurements of automated complete blood counts obtained from K2-EDTA-anticoagulated and hirudinised blood correlated significantly as did the measurements of 24 clinical chemistry analytes from hirudinised plasma and serum. Regression analysis revealed that the results of complete blood counts and clinical chemistry tests were predictable from the respective measurements from hirudinised blood (p=0.001). Immunohaematological tests and cross-matching from hirudinised and native blood of the same donors gave identical results. Single clotting factors, but not global coagulation analytes, could be measured from hirudinised blood. Therefore, a universal hirudin-containing blood sampling tube could be designed for automated analysis of haematological, serological and clinical chemistry analytes.