Fermi surface map of large-scale single-orientation graphene on SiO2.

Large scale tetraoctylammonium-assisted electrochemical transfer of graphene grown on single-crystalline Ir(1 1 1) films by chemical vapour deposition is reported. The transferred samples are characterized in air with optical microscopy, Raman spectroscopy and four point transport measurements, providing the sheet resistance and the Hall carrier concentration. In vacuum we apply low energy electron diffraction and photoelectron spectroscopy that indicate transferred large-scale single orientation graphene. Angular resolved photoemission reveals a Fermi surface and a Dirac point energy which are consistent with charge neutral graphene.

General Scheme for Oxidative Quenching of a Copper Bis-Phenanthroline Photosensitizer for Light-Driven Hydrogen Production.

A new, general reaction scheme for photocatalytic hydrogen production is presented based on oxidative quenching of a homoleptic copper(I) bis-1,10-phenanthroline photosensitizer (PS) by 1-methyl-4-phenyl-pyridinium (MPP(+) ) as the electron relay and subsequent regeneration of the so formed copper(II) complex by a sacrificial electron donor. Electron transfer from the relay to various cobalt based water reduction catalysts and subsequent H2 production was shown to close the catalytic cycle. Transient absorption experiments unambiguously confirmed the proposed pathway, both the oxidative quenching and subsequent regeneration of oxidized PS. Photocatalytic test runs further confirmed the role of MPP(+) and up to 10 turnovers were achieved in the relay. The performance limiting factor of the system was shown to be the decomplexation of the copper PS. Quantum yields of the system were 0.03 for H2 production, but 0.6 for MPP(.) formation, clearly indicating that unproductive pathways still prevail.

Cobalt complexes of tetradentate, bipyridine-based macrocycles: their structures, properties and photocatalytic proton reduction.

Complexes with purely pyridine-based macrocycles are rarely studied in photo(electro)catalysis. We synthesized and investigated macrocycles, in which two 2,2'-bipyridine (bpy) units are linked twice by two cyano-methylene groups, to yield the basic tetradentate, bipyridine based ligand framework (pyr). The protons in the bridges were substituted to obtain derivatives with one (pyr-alk) or two (pyr-alk2) alkyl-chains, respectively. We present the crystal structures of the mono-pentylated and the cis-dibutylated ligands. The corresponding Co(II) complexes [Co(II)(OH2)2(pyr)], [Co(II)Br(HOMe)(pyr-bu)], [Co(II)Br2(cis-pyr-bu2)] and [Co(II)Br2(trans-pyr-bu2)] were prepared, their physico-chemical properties elucidated and their crystal structures determined. X-ray analyses revealed for the latter three complexes distorted octahedral coordination and a fairly planar {Co(II)(pyr)} macrocyclic scaffold. The axial bromides in [Co(II)Br(HOMe)(pyr-bu)], [Co(II)Br2(cis-pyr-bu2)] and [Co(II)Br2(trans-pyr-bu2)] are weakly bound and dissociate upon dissolution in water. While the alkylated complexes are paramagnetic and feature Co(II) d(7) high spin configurations, the unsubstituted complex [Co(II)(OH2)2(pyr)] displays a rare Co(II) low spin configuration. The electronic ground states of [Co(II)Br2(cis-pyr-bu2)] and [Co(II)Br2(trans-pyr-bu2)] are similar, as evident from the almost identical UV/vis spectra. Electrochemical analyses show redox-non-innocent ligand frameworks. All complexes are highly robust and efficient H(+) reducing catalysts. In the presence of [Ru(bpy)3]Cl2 as a photosensitizer and TCEP/NaHasc as a sacrificial electron donor and shuttle, turnover numbers (TONs, H2/Co) up to 22 000 were achieved.

Photocatalytic proton reduction with ruthenium and cobalt complexes immobilized on fumed reversed-phase silica.

Heterogeneous photocatalytic hydrogen production with a non-covalently immobilized molecular ruthenium based photosensitizer (PS) and a cobalt polypyridyl based water reducing catalyst (WRC) is reported. PS and WRC were derivatized with C18-alkyl chains and immobilized by adsorption on hydrophobic fumed silica. The resulting loaded support was suspended in water with anionic or cationic surfactants and subjected to heterogeneous photocatalytic H2 production with ascorbate as sacrificial electron donor (SED). No leaching was observed under catalytic conditions, thus catalysis was truly heterogeneous. The catalytic performance of immobilized PS and WRC clearly exceeded that of homogeneous catalysis at low concentrations. At high concentration, diffusion and light limitation lead to lower reaction rates, but the same stability as for homogeneous reactions was still achieved. WRC concentration variations indicated a relatively high stability (up to 1300 H2/Co) and mobility of amphiphilic catalysts on the hydrophobic silica surface. Comparison of fumed silica with porous and non-porous silica showed, that a high BET surface area along with a good accessibility from the reaction media are crucial for catalytic performance. Mechanistic investigations by transient absorption spectroscopy displayed reductive quenching of excited PS by ascorbate followed by on particle electron transfer to WRC as reaction pathway. Particles with additional cationic surfactants exhibited a significantly higher catalytic performance as compared to anionic surfactants. Non-covalent anchoring of correspondingly derivatized WRCs or PSs to reversed-phase silica offers a rapid and versatile transition from homogeneous to heterogeneous molecular proton reduction.

Smac mimetics increase cancer cell response to chemotherapeutics in a TNF-α-dependent manner.

Second mitochondria-derived activator of caspase (Smac) is a mitochondrial protein released into the cytosol during apoptosis. Smac mimetics have recently been touted as a novel therapeutic to induce apoptosis in cancer cells. The ability of Smac mimetics to induce apoptosis in vitro has been shown to be dependent upon both XIAP neutralization and cancer cell autocrine tumor necrosis factor-α (TNF-α) production. In this study we provide new evidence for the utility of Smac mimetics in combination with conventional chemotherapy agents to exacerbate caspase activation and induce cancer cell death. Furthermore, we find that the combination effect is because of a multifaceted mechanism involving both inhibition of cell proliferation by the chemotherapy agents and an enhanced autocrine TNF-α feedback loop by the Smac mimetic/chemotherapy agent combination. Surprisingly, although genotoxic agents typically induce apoptosis through the mitochondrial intrinsic pathway, we show that this synergism is mediated through a TNF-α/RIP1-dependent pathway, leading to activation of the extrinsic apoptotic pathway. Finally, we report that autocrine TNF-α contributes to Smac mimetic-induced tumor regression as a single agent or in combination with chemotherapeutics in xenograft mouse models. Collectively, we provide mechanistic and applicable data to support translational studies in the use of a Smac mimetic/chemotherapy antineoplasm modality.

Bromelain reversibly inhibits invasive properties of glioma cells.

Bromelain is an aqueous extract from pineapple stem that contains proteinases and exhibits pleiotropic therapeutic effects, i.e., antiedematous, antiinflammatory, antimetastatic, antithrombotic, and fibrinolytic activities. In this study, we tested bromelain's effects on glioma cells to assess whether bromelain could be a potential contributor to new antiinvasive strategies for gliomas. Several complementary assays demonstrated that bromelain significantly and reversibly reduced glioma cell adhesion, migration, and invasion without affecting cell viability, even after treatment periods extending over several months. Immunohistochemistry and immunoblotting experiments demonstrated that alpha3 and beta1 integrin subunits and hyaluronan receptor CD44 protein levels were reduced within 24 hours of bromelain treatment. These effects were not reflected at the RNA level because RNA profiling did not show any significant effects on gene expression. Interestingly, metabolic labelling with 35-S methionine demonstrated that de novo protein synthesis was greatly attenuated by bromelain, in a reversible manner. By using a transactivating signaling assay, we found that CRE-mediated signaling processes were suppressed. These results indicate that bromelain exerts its antiinvasive effects by proteolysis, signaling cascades, and translational attenuation.

Can emergency physicians correlate between vehicle damage and velocity change?

The objective to this study was to examine the ability of emergency physicians to correlate between vehicle damage and velocity change. Participants were five emergency medicine physicians at the Emergency Department, Loyola University Medical Center, Maywood, IL. Ten slides of passenger cars crashed at speeds between 22 and 70 mph by the Insurance Institute for Highway Safety were shown to study participants. Study subjects were asked to estimate vehicular velocity based on the visible damage. Only 23 (46%) of the estimates were within 10 mph of the vehicular speed at the time of the crash. The average error was 14.5 mph (range: -20 to +45 mph). Vehicular velocity was overestimated in 70% of the appraisals. We conclude that the ability of emergency physicians to correlate between vehicle damage and velocity change is limited. Underestimation of vehicular damage associated with low velocity accidents may result in misdiagnosis of severe injuries in motor vehicle accident victims.

Hypertensive disorders of pregnancy.

Overall, the goal of the emergency physician is proper recognition of the gravid woman whose pregnancy is complicated by hypertensive disease, particularly preeclampsia-eclampsia. As the classic triad of hypertension, proteinuria, and edema does not always occur simultaneously, supporting signs and symptoms as well as laboratory data may be necessary to support the diagnosis. Once the diagnosis is established, drug therapy aimed at the prevention of seizures and emergent control of blood pressure should be instituted to stop progression of the disease. Although many agents are undergoing investigation, magnesium sulfate and hydralazine remain the drugs of choice for anticonvulsant and antihypertensive therapy, respectively. Early consultation with an obstetrician should facilitate timely termination of the pregnancy with the least possible trauma to the mother and infant.

Urinary estradiol-17 beta excretion in common marmosets, Callithrix jacchus: diurnal pattern and relationship between creatinine-related values and excreted amount.

1. The diurnal pattern of urinary estradiol and creatinine excretion was investigated in order to evaluate the relationship between total estradiol excretion per day and the estradiol concentration or the estradiol-to-creatinine ratio from single urine samples in female common marmosets (Callithrix j. jacchus). 2. During a 36-day period, urine was collected from five adult female marmosets in 3-hr intervals during the light time of an LD 12:12 (400:0.1 lx) which corresponded to the animals' activity time. 3. Estradiol concentration was determined by radioimmunoassay after glucuronidase treatment and creatinine concentration was measured photometrically. 4. Concentration and amount of excreted estradiol, and the creatinine concentration showed a distinct diurnal pattern with significantly higher levels at the beginning of the activity time compared to later sampling times. 5. No diurnal pattern was present in the estradiol-to-creatinine ratio, but the difference between lower follicular and higher luteal phase levels of estradiol excretion remained significant in the 36-day period. 6. Correlation analyses revealed significantly positive correlations between the total estrogen mass excreted per day and the estradiol-to-creatinine ratio in "morning urine" samples. 7. Thus the estradiol-to-creatinine ratio of single urine samples collected at the beginning of the activity time provides a reliable estimate of total estrogenic output in this species. 8. Studies of the circadian pattern of urinary hormone excretion, however, require total urine sampling.

An automated method for recording scent marking in Mongolian gerbils.

A device for the automated recording of scent-marking events in Mongolian gerbils (Meriones unguiculatus) is described. The method uses minute temperature changes occurring at the surface of marked objects to detect scent marking. These events are recorded by a computer together with the exact time and the location of the marked object. The data obtained with this temperature-sensitive recording method correlate well with data obtained in parallel by human observers. The measurement of the diurnal rhythm of scent-marking behavior for 5 consecutive days in an undisturbed male demonstrates the specific usefulness of this new recording method. In addition, this temperature-sensitive automated recording of scent-marking behavior may also be applicable in other animals that primarily mark protruding objects.

Neural androgen receptors and scent marking of male gerbils: modulation by females.

The involvement of brain cytosolic androgen receptors in the female-induced increase in scent-marking behavior of male Mongolian gerbils was studied. Scent-marking activities and serum testosterone concentrations were measured in low-marking control males and in males with increased scent-marking activities, stimulated by the presence of conspecific females in the same room. For every individual male the concentrations and affinities of androgen receptors were determined in four parts of the brain, which contained the hippocampus, septum, corpus striatum, amygdala, stria terminalis, and the hypothalamus. Compared to the basal unstimulated period, the marking activities of male gerbils significantly increased 58% during the presence of female conspecifics in their housing room. The serum testosterone concentrations did not change significantly during female presence. The association constants of the cytosolic androgen receptors were higher in the female-stimulated males compared to isolated control males. In contrast, the cytosolic receptor concentration was reduced. The difference reached significance in one of the brain parts. Individual levels in scent-marking activities could not be explained by correlation with individual androgen receptor parameters. The present results suggest that increased androgen binding in the brain may be involved in the elevation of scent-marking activities in male gerbils, caused by urinary chemical signals of female conspecifics.

Quantitative characterization of hormone receptors by a nonlinear regression approach.

This paper describes a mathematical model for the quantification of receptors based only upon the total bound values as a function of the total ligand concentration. In contrast to methods relying on linearization transformations, this nonlinear model requires more sophisticated computation, however, avoids loss of material for determination of nonspecific binding in competed tubes. Monte-Carlo simulation indicated high stability of this model against random experimental error. The androgen receptor of the male gerbil (Meriones unguiculatus) ventral prostate is characterized using the described nonlinear computation.

[Social integration of Crohn disease and ulcerative colitis patients. Study of the relations of somatic, psychological and social factors]. / Soziale Integration von Morbus Crohn- und Colitis ulcerosa-Patienten. Studie zur Wechselwirkung somatischer, psychischer und sozialer Faktoren.

63 patients with Crohn's disease and 58 patients with ulcerative colitis were tested with the "Fragebogen zur sozialen Integration" (FSI, questionnaire of social adjustment), the "Freiburger Persönlichkeitsinventar" (FPI) and a semistandardized interview and were compared with surgical controls. Activity, course and symptoms of the disease were registered. We found significant restrictions in working and lesiure activities, partnership and sexual life in patients with inflammatory bowel disease. Social adjustment of patients with Crohn's disease was more dependent on disease activity than in patients with ulcerative colitis. Social impairment in patients with Crohn's disease correlated with higher stool frequency and abdominal pain, in patients with ulcerative colitis with reduced general state of health, tiredness and limpness. In the "Freiburger Persönlichkeitsinventar" (FPI) the patients with chronic inflammatory bowel disease described themselves significantly more nervous, inhibited, reserved and less aggressive, sociable and composed. The FPI scores in patients with Crohn's disease depended more on disease activity and on somatic symptoms than in patients with ulcerative colitis.

Mentor program for high school students.

As the nation grapples with the latest shortage of registered professional nurses, a creative solution, with an eye toward nursing in the 21st century, is the Mentor Program in Nursing for high school students at The Mount Sinai Medical Center in New York City. The registered professional nurses on staff at the medical center have made a commitment to this program as a way of encouraging a continuous supply of future nurses.

[Psychological reflections by adolescents on the atomic threat]. / Psychische Widerspiegelungen der atomaren Bedrohung bei Jugendlichen.

The results are focussed on the three most important wishes and fears of 247 adolescents aged 14 years whose development is being followed from birth in the framework of the Rostock Longitudinal Study. The peace/war problem occupies a central position in the thinking of adolescents today. However there are no indications that the individual perception of and reflection on the nuclear threat impair psychic development nor is there any relation between political fears and the anxiety trait. The extension of personal wishes and fears to broader fields of significance and the facing up to world problems constitute signs of a maturing personality and a widened consciousness of reality. Psychic coping of such global fears will be facilitated the more the individual gains personal experience of the effectiveness of peace policies and activities--not least by making his/her own contribution.

Developmental changes in the pituitary-gonadal-axis in male Mongolian gerbils from birth to adulthood.

The development of the pituitary-gonadal-axis and of body and organ weights was investigated in male Mongolian gerbils. During the neonatal period from birth to 7 days of age testicular activity was high but decreased to low prepubertal levels from 7 to 28 days of age. The pubertal period occurred from 1 to 3 months of age and was characterized by an intense rise in serum testosterone concentrations and in testicular testosterone production in-vitro. At 2.5 months of age accessory organs achieved their adult weight, at the same time as both, serum testosterone concentration and in-vitro testosterone production, reached their respective maximum levels. From 4 until 24 months of age no further relevant changes occurred in the pituitary-gonadal-axis. This study demonstrates that the testicular responsiveness is an important factor for the pubertal increase of testosterone during sexual maturation of male Mongolian gerbils.