Investigating charge-up and fragmentation dynamics of oxygen molecules after interaction with strong X-ray free-electron laser pulses

The X-ray-induced charge-up and fragmentation process of a small molecule is examined in great detail by measuring the molecular-frame photoelectron interference pattern in conjunction with other observables in coincidence.

Photon-recoil imaging: Expanding the view of nonlinear x-ray physics

Addressing the ultrafast coherent evolution of electronic wave functions has long been a goal of nonlinear x-ray physics. A first step toward this goal is the investigation of stimulated x-ray Raman scattering (SXRS) using intense pulses from an x-ray free-electron laser. Earlier SXRS experiments relied on signal amplification during pulse propagation through dense resonant media. By contrast, our method reveals the fundamental process in which photons from the primary radiation source directly interact with a single atom. We introduce an experimental protocol in which scattered neutral atoms rather than scattered photons are detected. We present SXRS measurements at the neon K edge and a quantitative theoretical analysis. The method should become a powerful tool in the exploration of nonlinear x-ray physics.

Studies for aluminum photoionization in hot cavity for the selective production of exotic species project

Selective production of exotic species (SPES) is an ISOL-based accelerator facility that will be built in the Legnaro INFN Laboratory (Italy), intended to provide an intense neutron-rich radioactive ion beams obtained by proton induced fission of an uranium carbide target. Beside this main target, a silicon carbide (SiC) target will the first to be used to deliver some p-rich beams. This target will validate also the functionality of the SPES facility with aluminum beam as result of hitting SiC target with protons. In the past off-line studies on laser photoionization of aluminum have performed in Pavia Spectroscopy Laboratory and in Laboratori Nazionali di Legnaro where, recently, a XeCl excimer laser was installed in order to test the laser ionization in the SPES hot cavity. Results are promising to justify further studies with this technique, aiming a better characterization of the SPES ion extraction capability under laser photoionization.

Off-line ionization tests using the surface and the plasma ion sources of the SPES project

The development of new target ion source systems for the selective production of exotic species (SPES) facility is currently in progress at Legnaro National Laboratories. In this context, the study of ion sources and their performance in terms of ionization efficiency and transversal emittance is a crucial point in order to maximize the available yields, particularly for short-lived isotopes. In this work, preliminary off-line ionization efficiency and emittance measurements for the SPES surface and plasma ion sources are presented. The plasma source emittance measurements are supported by dedicated numerical calculations.

Rolling circle amplification: a new approach to increase sensitivity for immunohistochemistry and flow cytometry

Immunohistochemistry is a method that can provide complementary diagnostic and prognostic information to morphological observations and soluble assays. Sensitivity, specificity, or requirements for arduous sample preparation or signal amplification procedures often limit the application of this approach to routine clinical specimens. Rolling circle amplification (RCA) generates a localized signal via an isothermal amplification of an oligonucleotide circle. The application of this approach to immunohistochemistry could extend the utility of these methods to include a more complete set of immunological and molecular probes. RCA-mediated signal amplification was successfully applied to the sensitive and specific detection of a variety of cell surface antigens (CD3, CD20, and epithelial membrane antigen) and intracellular molecules (vimentin and prostate-specific antigen) within a variety of routinely fixed specimens, as well as samples prepared for flow cytometry. RCA technology, which has an intrinsically wide dynamic range, is a robust and simple procedure that can provide a universal platform for the localization of a wide variety of molecules as a function of either antigenicity or nucleic acid sequence. The use of RCA in this way could enhance the use of markers of current interest as well as permit the integration of emerging information from genomics and proteomics into cell- and tissue-based analyses.

Hyperbaric oxygen treatment during pregnancy in acute carbon monoxide poisoning. A case report

BACKGROUND

Carbon monoxide poisoning in pregnancy is a relatively rare occurrence, with potentially serious complications for both mother and fetus. Controversy regarding treatment during pregnancy exists primarily due to the concern for oxygen toxicity in the fetus. However, rapid oxygen dissociation and prolonged clearance of carbon monoxide in the fetal circulation emphasize the importance of adhering to aggressive treatment protocols.

CASE

A 22-year-old employee at an office undergoing repairs on the heating and ventilation systems presented with neurologic symptoms, tachycardia, tachypnea, signs of preterm labor and a carboxyhemoglobin level that was mildly elevated. Fetal monitoring demonstrated a reactive nonstress test with mild to moderate repetitive variable decelerations. The patient underwent hyperbaric oxygen treatment, with complete resolution of her neurologic symptoms, tachycardia and tachypnea as well as fetal variable decelerations. She was additionally treated with intravenous magnesium sulfate tocolysis, with cessation of contractions. The patient subsequently delivered at term; the viable infant had no sequelae of in utero carbon monoxide poisoning.

CONCLUSION

This case supports previously published recommendations for treating acute carbon monoxide poisoning during pregnancy with hyperbaric oxygen. As more cases are gathered, a more widely accepted set of standards can be established.

Handicap versus impairment: an important distinction

In this era of spiraling health care costs, audiologists are being held accountable for the rehabilitative interventions that they are uniquely qualified to deliver. Accountability data in the rehabilitative arena should address the efficacy of short- and long-term treatment. If a treatment such as a hearing aid is dispensed for the purpose of reducing the communicative and psychosocial handicap associated with hearing loss, efficacy data should demonstrate whether such a goal has been attained. Increased attention has been focused on the value of self-assessment questionnaires as instruments that are predictive of candidacy for hearing aids, intent to purchase hearing aids, and outcomes with a given hearing aid treatment. Case studies demonstrate the advantage of engaging the client in the rehabilitative process through the use of responses to self-assessment questionnaires. It is evident that the client's appraisal of the handicapping effect of a given impairment is associated with treatment efficacy.

Production of tumor necrosis factor/cachectin by peripheral blood mononuclear cells in patients with systemic lupus erythematosus

Levels of tumor necrosis factor/cachectin (TNF alpha) assessed by ELISA were similar in the supernatant of cultures from peripheral blood mononuclear cells (PBMC) from either active or inactive systemic lupus erythematosus (SLE) patients and controls stimulated with mitogen alone. When PBMC were stimulated with mitogen plus phorbol 12-myristate-13-acetate (PMA), the amount of TNF alpha was significantly decreased in culture supernatants from active patients or from the entire group of SLE patients studied. However, spontaneous synthesis of TNF alpha in nonstimulated cultures was increased in the SLE patients. Interferon-gamma (IFN-gamma) enhanced TNF alpha synthesis in cultures from either SLE patients or controls stimulated by concanavalin A (Con A) alone, but depressed the high production of TNF alpha by normal PBMC stimulated with Con A plus PMA. IFN-gamma enhanced TNF alpha production in response to Con A plus PMA in 2 of 3 SLE patients.

Kappa/lambda immunoglobulin distribution in Graves' thyroid-stimulating antibodies. Simultaneous analysis of C lambda gene polymorphisms

From patients with untreated Graves' disease 11 sera showing high cAMP release in the FRTL-5 cell assay were studied for relative proportions of kappa or lambda Ig molecules showing cAMP releasing activity. Immunoabsorption of gamma-globulins was performed using monoclonal murine anti-kappa or anti-lambda antibodies linked to cyanogen bromide-activated sepharose. Specific kappa- or lambda-adsorbed fractions were also eluted from immunoabsorbents using chaotrophic thiocyanate buffers and equilibrated with pH 7.4 low salt buffer by dialysis. Immunoabsorption and elution experiments showed that five Graves' sera contained predominant cAMP-releasing activity within lambda Ig fractions, whereas two Graves' sera showed predominant cAMP-releasing activity in kappa Ig fractions. Four sera showed cAMP release approximately equally divided between kappa and lambda Ig both after immunoabsorption and specific anti-kappa or anti-lambda eluates were studied. C lambda genotypes were examined by Southern blotting and restriction fragment length polymorphism analysis of Eco RI-digested genomic DNA from 158 patients with Graves' disease in parallel with 112 normal controls and 29 patients with autoimmune hypothyroidism. Notable shifts in proportions of 8/8 and 18/18 genotypes were present when Graves' patients were compared with normal controls. Allelic frequencies and ratios of genotype 8 to 18 were significantly different (P less than 0.05) when Graves' patients were compared either to normal controls or to patients with autoimmune hypothyroidism.

Studies of possible antiidiotypic control mechanisms in Graves' disease

Serum from 55 patients with active Graves' disease and 55 patients who had received successful treatment (in whom the disease was inactive) were examined for the presence of possible antiidiotypic antibodies with an enzyme-linked immunosorbent assay (ELISA) for anti-F(ab')2. Murine IgG monoclonal antibodies (Mabs) against human thyroid-stimulating hormone (TSH) and human TSH receptors were also used as antigens in parallel ELISA assays. Patients with active and patients with inactive Graves' disease showed elevations of IgG anti-F(ab')2 antibodies when compared with normal controls. Similarly, both active and inactive Graves' disease sera showed higher levels of IgG anti-LE4, a mouse Mab to human TSH, than was seen with normal controls. However, F(ab')2 isolated from sera reacting with LE4 in the ELISA did not inhibit binding of the LE4 Mab with labeled TSH in a fluid phase competition assay. Patients with inactive Graves' disease showed higher ELISA reactivity with two different murine anti-TSH receptor Mabs than was recorded with either active Graves' or normal controls. A rough inverse correlation was noted between strongly positive ELISA reactions against these two Mabs with anti-TSH receptor specificity and the ability of immunoglobulins from inactive Graves' sera to stimulate increases in cyclic adenosine monophosphate (cAMP) in the normal rat thyroid cell line assay. Untreated Graves' sera showing high cAMP release only rarely showed elevated ELISA reactivity against Mabs with anti-TSH receptor activity.

Prophylactic antibiotics and no antibiotics compared in penetrating chest trauma

Conflicting data exist concerning the value of antimicrobial prophylaxis in chest trauma. In a prospective and randomized study, we assessed the value of antibiotic prophylaxis in 80 consecutive relatively young, predominantly male patients admitted for gunshot or knife injuries of the chest. Forty patients received intravenous doxycycline and 40 received no antibiotic. Between the two groups we found no difference in the incidence of postoperative infections: we conclude that routine antibiotic prophylaxis is not recommended in penetrating chest trauma in patients such as ours.

N(2) fixation and h(2) evolution by six species of tropical leguminous trees

The C(2)H(4)/(15)N(2) and H(2)/(15)N(2) ratios for six species of tropical leguminous trees are reported. C(2)H(4)/(15)N(2) ratios ranged from 2.4 to 4.7; values for the H(2)/(15)N(2) ratios were between 0.6 and 1.4. Relative efficiency values, based on C(2)H(2) reduction, (15)N incorporation, and H(2) evolution during (15)N incorporation varied between 0.68 and 0.84 for the six species. Overall, approximately 30% of the electron flow through nitrogenase was used for H(2) evolution.

Social and psychologic influences on employment of married nurses

Seven summary factors were obtained from a principal components factor analysis and Varimax rotation of 21 variables, based on 145 pieces of information given by 1,998 nurses in metropolitan Detroit, Michigan, in 1973. Study nurses were under 60 years of age, were married and living with spouse, and had at least one child 18 or younger. The factors were: career desirability, professional attitude, professional behavior, achievement personality, conducive home situation, economic value of work, and satisfaction with nursing. When these factors were compared with employment status-1) current employment activity of all subjects, 2) subjects whose employment status was constant for five years, highest scores were registered in both categories on career desirability, professional behavior, and economic value of work. Both groups of nurses scored lowest on satisfaction with nursing, with the five-year employees scoring lower. When the seven factors were correlated with employment status while controlling financial need and age of youngest child at home, highest correlation scores resulted for professional behavior, career desirability, and, in the case of those with financial need, on the economic value of nursing.