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Health care workers (n = 342) completed items examining their emotional experiences working with HIV-positive patients. Factor analysis produced two subscales: Personal Satisfaction and Emotional Stress. A subset of these care workers (n = 251) claimed increased stress and depression after 6 months. In a second study, 91 volunteer AIDS caregivers ("buddies") completed the inventory and the Attitude Toward AIDS Scale. Satisfaction subscores were related to frequent contact and Stress subscores were related to length of illness of persons with AIDS. Satisfaction subscores were related negatively to prejudice towards PWA, social discrimination against PWA, and positively to pro-attitudes toward PWA. Stress subscores were related to social discrimination and punishment for PWA. [ABSTRACT FROM AUTHOR]

N-Heterocyclic carbenes (NHCs) are an emerging alternative to thiols for the formation of stable self-assembled monolayers (SAMs) on gold. We examined several different species that have been used to produce NHC-based monolayers on gold, namely 1,3-diisopropyl-5-nitrobenzimidazolium iodide, 1,3-diisopropyl-5-nitrobenzimidazolium hydrogen carbonate, bis(1,3-diisopropyl-5-nitrobenzimidazolium)gold(I) iodide, and 1,3-diisopropyl-5-nitrobenzimidazole-2-ylidene. Contrary to expectation, solutions containing the first two species in tetrahydrofuran and dichloromethane caused visible loss of gold from thin-film-coated glass slides. The use of toluene solutions of all species resulted in no apparent dissolution of gold. We present scanning electron micrographs and elemental imaging analyses by energy dispersive X-ray spectroscopy to examine the effect of solutions of each species on the gold film. This work highlights the risk of unwanted etching during some routes to NHC-based surface functionalization but also the potential for deliberate etching, with the outcome determined by choice of chemically synthesized organic species and solvent., (Copyright © 2023, Chevalier et al.)

Here, we report on the successful demonstration and application of carbonate (CO 3 2- ) ion-selective amperometric/voltammetric nanoprobes based on facilitated ion transfer (IT) at the nanoscale interface between two immiscible electrolyte solutions. This electrochemical study reveals critical factors to govern CO 3 2- -selective nanoprobes using broadly available Simon-type ionophores forming a covalent bond with CO 3 2- , i.e., slow dissolution of lipophilic ionophores in the organic phase, activation of hydrated ionophores, peculiar solubility of a hydrated ion-ionophore complex near the interface, and cleanness at the nanoscale interface. These factors are experimentally confirmed by nanopipet voltammetry, where a facilitated CO 3 2- IT is studied with a nanopipet filled with an organic phase containing the trifluoroacetophenone derivative CO 3 2- ionophore (CO 3 2- ionophore VII) by voltammetrically and amperometrically sensing CO 3 2- in water. Theoretical assessments of reproducible voltammetric data confirm that the dynamics of CO 3 2- ionophore VII-facilitated ITs (FITs) follows the one-step electrochemical (E) mechanism controlled by both water-finger formation/dissociation and ion-ionophore complexation/dissociation during interfacial ITs. The yielded rate constant, k 0 = 0.048 cm/s, is very similar to the reported values of other FIT reactions using ionophores forming non-covalent bonds with ions, implying that a weak binding between CO 3 2- ion-ionophore enables us to observe FITs by fast nanopipet voltammetry regardless of the nature of bondings between the ion and ionophore. The analytical utility of CO 3 2- -selective amperometric nanoprobes is further demonstrated by measuring the CO 3 2- concentration produced by metal-reducing bacteria Shewanella oneidensis MR-1 as a result of organic fuel oxidation in bacterial growth media in the presence of various interferents such as H 2 PO 4 - , Cl - , and SO 4 2- .

We study public policies designed to improve access and reduce costs for in vitro fertilization (IVF). High out-of-pocket prices can deter potential patients from IVF, while active patients have an incentive to risk costly high-order pregnancies to improve their odds of treatment success. We analyze IVF's rich choice structure by estimating a dynamic model of patients' choices within and across treatments. Policy simulations show that insurance mandates for treatment or hard limits on treatment aggressiveness can improve access or costs, but not both. Insurance plus price-based incentives against risky treatment, however, can together improve patient welfare and reduce medical costs.

Fueled by new evidence, there has been renewed interest about the effects of birth order on human capital accumulation. The underlying causal mechanisms for such effects remain unsettled. We consider a model in which parents impose more stringent disciplinary environments in response to their earlier-born children's poor performance in school in order to deter such outcomes for their later-born offspring. We provide robust empirical evidence that school performance of children in the National Longitudinal Study Children (NLSY-C) declines with birth order as does the stringency of their parents' disciplinary restrictions. When asked how they will respond if a child brought home bad grades, parents state that they would be less likely to punish their later-born children. Taken together, these patterns are consistent with a reputation model of strategic parenting.

An in vitro activation assay for identifying suspected indirect mutagens and/or carcinogens is described. It involves the incubation of diffusion chambers filled with S-9 mix (S-9 fraction of rat liver and enzyme cofactors) and a compound under test with mammalian cells. The induction of sister chromatid exchanges (SCE) and/or chromosome aberrations can then be used as an indicator of mutagenicity or carcinogenicity. When a human lymphoid cell line, B35M, or Chinese hamster cell lines, V79 and CHO, are cultured with the diffusion chamber containing S-9 mix and the well-known indirect mutagen cyclophosphamide or its analog ifosfamide, a dose related increase in SCE or chromosome aberrations is observed in all the lines. The major advantages of this system over other in vitro activation assays are alleviation of cytotoxicity of S-9 mix and flexibility of treatment time.

Sixty well-conditioned runners were evaluated for arrhythmias by Holter monitor during both a distance run and a maximal treadmill test. Twenty-seven percent of subjects had ventricular arrhythmias during treadmill testing, only 3% having grades higher than just an occasional isolated premature ventricular complex (PVC), compared with 60% during the monitored run, of which ventricular bigeminy occurred in 10%, ventricular couplets in 10%, and multiform PVCs in 5%. Treadmill testing significantly underestimated the frequency and grade of both atrial and ventricular arrhythmias: 57% of subjects who had ventricular arrhythmias while running had none on the treadmill, and 11 of 16 who had ventricular arrhythmias on the treadmill had up to 3 grades higher on the run. The discovery of frequent high-grade atrial and ventricular arrhythmias in subjects considered to be completely fit and healthy suggests that such variations in heart rhythm are a normal phenomenon and no more specific for heart disease or risk than ventricular arrhythmias during maximal treadmill exercise testing.

A cDNA for rat liver beta-glucuronidase was isolated, its sequence determined and its expression after transfection into COS cells studied. The deduced amino acid sequence of the rat liver clone showed 77% homology with that from the cDNA for human placental beta-glucuronidase and 47% homology with that deduced from the cDNA for Escherichia coli beta-glucuronidase. Several differences were found between the cDNA from rat liver and that previously reported from rat preputial gland. Only one change leads to an amino acid difference in the mature enzyme. A chimeric clone was constructed by using a fragment encoding the first 18 amino acid residues of the signal sequence from the human placental cDNA clone and a fragment from the rat clone encoding four amino acid residues of the signal sequence, all 626 amino acid residues of the mature rat enzyme, and all of the 3' untranslated region. After transfection into COS cells the chimeric clone expressed beta-glucuronidase activity that was specifically immunoprecipitated by antibody to rat beta-glucuronidase. The Mr value of 76,000 of the expressed gene product was characteristic of the glycosylated rat enzyme. It was proteolytically processed in COS cells to Mr 75,000 6 h after metabolic labelling. At least 50% of the expressed enzyme was secreted at 60 h post-transfection, but the secreted enzyme did not undergo proteolytic processing. These results provide evidence that the partial cDNA isolated from a rat liver library contains the complete coding sequence for the mature rat liver enzyme and that the chimeric signal sequence allows normal biosynthesis and processing of the transfected rat liver enzyme in COS cells.

A knife wound of the heart produced a ventricular septal defect. Surgical repair of a myocardial laceration and pericardiotomy for relief of cardiac tamponade were performed. Progressive exercise intolerance developed over an 8-year period. In addition, the patient experienced intermittent partial cardiac herniation resulting in angina-like chest pain. The patient is now asymptomatic after correction of the pericardial defect and closure of the ventricular septal defect.