Multiple vanishing tumours simulating pulmonary neoplasms. A case report

CITATION: Van Gelderen, W.F.C. 1989. Multiple vanishing tumours simulating pulmonary neoplasms. A case report. S Afr Med J, 75:498-499.The original publication is available at http://www.samj.org.zaVanishing fluid collection (or tumour) in an interlobar fissure associated with congestive cardiac failure is not common. Multiple vanishing tumours are most uncommon and can resemble other multiple opacities, e.g. metastases. The disappearance of these so-called tumours after treatment for cardiac failure provided proof of the diagnosis in the patient reported. This diagnosis is important to consider in order to prevent unnecessary investigation and treatment.Publisher’s versio

Stigmatization associated with growing up in a lesbianparented family: What do adolescents experience and how do they deal with 140

The purpose of the current qualitative study was to investigate whether adolescents in American planned lesbian families experienced negative reactions from their social environment associated with their mothers' sexual orientation, and if so, to explore the nature of these experiences. In addition, the focus was on the coping strategies as described by the adolescents themselves. Results revealed that half of the 78 participating 17-years-olds had experienced homophobic stigmatization. Such experiences usually took place within the school context and peers were most frequently mentioned as the source. The adolescents used adaptive strategies (such as optimism) more frequently than maladaptive strategies (such as avoidance) to cope with these negative experiences. Our results suggest that intervention programs focused on family diversity should be developed for school children of all ages since the stigmatization experienced by the studied adolescents typically happened in that context

Stigmatization associated with growing up in a lesbianparented family: What do adolescents experience and how do they deal with 140

The purpose of the current qualitative study was to investigate whether adolescents in American planned lesbian families experienced negative reactions from their social environment associated with their mothers' sexual orientation, and if so, to explore the nature of these experiences. In addition, the focus was on the coping strategies as described by the adolescents themselves. Results revealed that half of the 78 participating 17-years-olds had experienced homophobic stigmatization. Such experiences usually took place within the school context and peers were most frequently mentioned as the source. The adolescents used adaptive strategies (such as optimism) more frequently than maladaptive strategies (such as avoidance) to cope with these negative experiences. Our results suggest that intervention programs focused on family diversity should be developed for school children of all ages since the stigmatization experienced by the studied adolescents typically happened in that context

MicroRNA-132 regulates salt-dependent steady-state renin levels in mice

The body's salt and fluid balance is regulated by the renin-angiotensin-aldosterone system. Generation of prostaglandin-E2 (PGE2) in a cyclo-oxygenase-2 (COX-2)-dependent manner in the macula densa, the salt-sensing cells of the kidney, plays a dominant role in renin regulation. Here we show that miR-132 directly targets Cox-2 and affects subsequent PGE2 and renin levels. MiR-132 is induced and reduced by low- and high salt treatment, respectively, in a p38- and ERK1/2-independent and CREB- and salt inducible kinase-dependent manner. Silencing of miR-132 in mice increases macula densa COX-2 expression and elevates PGE2 and renin levels, which are abrogated by the selective COX-2-inhibitor Celecoxib. Furthermore, a low or high salt diet induces and reduces macula densa miR-132 expression, while low salt diet combined with silencing miR-132 further increases renin levels. Taken together, we demonstrate a posttranscriptional regulatory role for salt-dependent miR-132 in fine-tuning the steady-state levels of renin.Nephrolog

CaB_6: a new semiconducting material for spin electronics

Ferromagnetism was recently observed at unexpectedly high temperatures in La-doped CaB_6. The starting point of all theoretical proposals to explain this observation is a semimetallic electronic structure calculated for CaB_6 within the local density approximation. Here we report the results of parameter-free quasiparticle calculations of the single-particle excitation spectrum which show that CaB_6 is not a semimetal but a semiconductor with a band gap of 0.8 eV. Magnetism in La_xCa_{1-x}B_6 occurs just on the metallic side of a Mott transition in the La-induced impurity band.Comment: 4 pages, 1 postscript figur

Important factors for effective patient safety governance auditing: a questionnaire survey

BACKGROUND: Audits are increasingly used for patient safety governance purposes. However, there is little insight into the factors that hinder or stimulate effective governance based on auditing. The aim of this study is to quantify the factors that influence effective auditing for hospital boards and executives.METHODS: A questionnaire of 32 factors was developed using influencing factors found in a qualitative study on effective auditing. Factors were divided into four categories. The questionnaire was sent to the board of directors, chief of medical staff, nursing officer, medical department head and director of the quality and safety department of 89 acute care hospitals in the Netherlands.RESULTS: We approached 522 people, of whom 211 responded. Of the 32 factors in the questionnaire, 30 factors had an agreement percentage higher than 50%. Important factors per category were 'audit as an improvement tool as well as a control tool', 'department is aware of audit purpose', 'quality of auditors' and 'learning culture at department'. We found 14 factors with a significant difference in agreement between stakeholders of at least 20%. Amongst these were 'medical specialist on the audit team', 'soft signals in the audit report', 'patients as auditors' and 'post-audit support'.CONCLUSION: We found 30 factors for effective auditing, which we synthesised into eight recommendations to optimise audits. Hospitals can use these recommendations as a framework for audits that enable boards to become more in control of patient safety in their hospital

Parental positive affect and negative affect in same- and different-sex parent families: no associations with parental gender and caregiving role

Positive and negative parental affect influence developing parent–child attachment relationships, especially during infancy as well as children’s social–emotional, academic, and behavioral functioning later in life. Increasingly, because both mothers and fathers can play central caregiving roles, the parenting qualities of both parents demand consideration. Therefore, this study investigated whether parental gender and caregiving role were associated with mothers’ and fathers’ positive affect and negative affect during interactions with their 4-month-old firstborn infant, while determining whether parenting stress, infant temperament, having a singleton/twin, and living in the Netherlands, France, or the United Kingdom were related to parental positive affect and negative affect. In all, 135 different-sex, same-sex male, and same-sex female couples (113 fathers and 157 mothers, comprising 147 primary, and 123 secondary caregivers) who conceived through artificial reproductive techniques were studied. The couples were videorecorded at home while in feeding, cleaning, and playing contexts to assess the levels of positive and negative parental affect. In addition, the couples completed questionnaires about their caregiving role, parenting stress, and the infants’ temperament. Mixed linear models indicated that the levels of positive and negative parental affect toward the infant in all contexts were not related to parental gender, caregiving role, the interaction between parental gender and caregiving role, parenting stress, infant temperament, or singleton/twin status. However, the target parental behaviors were related to the country of origin, suggesting differences among Dutch, French, and British parents. Overall, we found no evidence that gender or caregiving roles were associated with the levels of positive and negative affect shown by the parents

Quantum dots and spin qubits in graphene

This is a review on graphene quantum dots and their use as a host for spin qubits. We discuss the advantages but also the challenges to use graphene quantum dots for spin qubits as compared to the more standard materials like GaAs. We start with an overview of this young and fascinating field and will then discuss gate-tunable quantum dots in detail. We calculate the bound states for three different quantum dot architectures where a bulk gap allows for confinement via electrostatic fields: (i) graphene nanoribbons with armchair boundary, (ii) a disc in single-layer graphene, and (iii) a disc in bilayer graphene. In order for graphene quantum dots to be useful in the context of spin qubits, one needs to find reliable ways to break the valley-degeneracy. This is achieved here, either by a specific termination of graphene in (i) or in (ii) and (iii) by a magnetic field, without the need of a specific boundary. We further discuss how to manipulate spin in these quantum dots and explain the mechanism of spin decoherence and relaxation caused by spin-orbit interaction in combination with electron-phonon coupling, and by hyperfine interaction with the nuclear spin system.Comment: 23 pages, 10 figures, topical review prepared for Nanotechnolog

Edge States of Monolayer and Bilayer Graphene Nanoribbons

On the basis of tight-binding lattice model, the edge states of monolayer and bilayer graphene nanoribbons (GNRs) with different edge terminations are studied. The effects of edge-hopping modulation, spin-orbital coupling (SOC), and bias voltage on bilayer GNRs are discussed. We observe the following: (i) Some new extra edge states can be created by edge-hopping modulation for monolayer GNRs. (ii) Intralayer Rashba SOC plays a role in depressing the band energy gap $E_g$ opened by intrinsic SOC for both monolayer and bilayer GNRs. An almost linear dependent relation, i.e., $E_g\sim \lambda_R$, is found. (iii) Although the bias voltage favors a bulk energy gap for bilayer graphene without intrinsic SOC, it tends to reduce the gap induced by intrinsic SOC. (iv) The topological phase of the quantum spin Hall effect can be destroyed completely by interlayer Rashba SOC for bilayer GNRs.Comment: 6 pages, 6 figure

Electronic Structure of Calcium Hexaboride within the Weighted Density Approximation

We report calculations of the electronic structure of CaB$_6$ using the weighted density approximation (WDA) to density functional theory. We find a semiconducting band structure with a sizable gap, in contrast to local density approximation (LDA) results, but in accord with recent experimental data. In particular, we find an $X$-point band gap of 0.8 eV. The WDA correction of the LDA error in describing the electronic structure of CaB$_6$ is discussed in terms of the orbital character of the bands and the better cancelation of self-interactions within the WDA.Comment: 1 figur