Decision for disclosure: The experiences of Iranian infertile couples undergoing assisted reproductive donation procedures

Controversy surrounding disclosure among the recipients of assisted reproductive donation procedures is escalating worldwide, but little research has been conducted in this topic. The purpose of this qualitative study was to explore the experiences of infertile couples undergoing assisted reproductive donation procedures. In this exploratory qualitative study, 32 patients (nine couples and 14 women) who were candidates to use donor eggs, donor embryos or surrogacy, and 5 members of infertility treatment team including gynaecologists, midwives and psychologist (total 37) were purposively selected from the Montaserieh Infertility Research Centre at Mashhad, Iran in 2012 and interviewed using a semi-structured in-depth method. Data were analysed using conventional qualitative content analysis with MAXqda software. One overarching theme, entitled ‘experiencing uncertainty surrounding the disclosure to others’ was identified from the data. This theme contained two subthemes including ‘Couples’ decisions to not disclose to others’ and ‘Couples’ decisions to disclose to others’. Five categories formed the first subtheme, and the second subtheme emerged from four categories which are discussed in this paper. The main reason for secrecy was concern over societal negative views about assisted reproductive donation procedures. This worry deprived the couples from support from family and friends and as a result requires them to tolerate psychological pressure when using such procedures.     

Conductance enlargement in picoscale electroburnt graphene nanojunctions

Provided the electrical properties of electroburnt graphene junctions can be understood and controlled, they have the potential to underpin the development of a wide range of future sub-10-nm electrical devices. We examine both theoretically and experimentally the electrical conductance of electroburnt graphene junctions at the last stages of nanogap formation. We account for the appearance of a counterintuitive increase in electrical conductance just before the gap forms. This is a manifestation of room-temperature quantum interference and arises from a combination of the semimetallic band structure of graphene and a cross-over from electrodes with multiple-path connectivity to single-path connectivity just before breaking. Therefore, our results suggest that conductance enlargement before junction rupture is a signal of the formation of electroburnt junctions, with a picoscale current path formed from a single sp² bond.Graphene nanojunctions are attractive as electrodes for electrical contact to single molecules (1–7), due to their excellent stability and conductivity up to high temperatures and a close match between their Fermi energy and the HOMO (highest occupied molecular orbital) or LUMO (lowest unoccupied molecular orbit) energy levels of organic materials. Graphene electrodes also facilitate electrostatic gating due to their reduced screening compared with more bulky metallic electrodes. Although different strategies for forming nanogaps in graphene such as atomic force microscopy, nanolithography (8), electrical breakdown (9), and mechanical stress (10) have been used, only electroburning delivers the required gap-size control below 10 nm (11–13). This new technology has the potential to overcome the challenges of making stable and reproducible single-molecule junctions with gating capabilities and compatibility with integrated circuit technology (14) and may provide the breakthrough that will enable molecular devices to compete with foreseeable developments in Moore’s law, at least for some niche applications (15–17).One set of such applications is likely to be associated with room-temperature manifestations of quantum interference (QI), which are enabled by the small size of these junctions. If such interference effects could be harnessed in a single-molecule device, this would pave the way toward logic devices with energy consumption lower than the current state-of-the-art. Indirect evidence for such QI in single-molecule mechanically controlled break junctions has been reported recently in a number of papers (18), but direct control of QI has not been possible because electrostatic gating of such devices is difficult. Graphene electroburnt junctions have the potential to deliver direct control of QI in single molecules, but before this can be fully achieved, it is necessary to identify and differentiate intrinsic manifestations of room-temperature QI in the bare junctions, without molecules. In the present paper, we account for one such manifestation, which is a ubiquitous feature in the fabrication of picoscale gaps for molecular devices, namely an unexpected increase in the conductance before the formation of a tunnel gap.Only a few groups in the world have been able to implement electroburning method to form nanogap-size junctions. In a recent study of electroburnt graphene junctions, Barreiro et al. (19) used real-time in situ transmission electron microscopy (TEM) to investigate this conductance enlargement in the last moment of gap formation and ruled out the effects of both extra edge scattering and impurities, which reduce the current density near breaking. Also, they showed that the graphene junctions can be free of contaminants before the formation of the nanogap. Having eliminated these effects, they suggested that the enlargement may arise from the formation of the seamless graphene bilayers. Here we show that the conductance enlargement occurs in monolayer graphene, which rules out an explanation based on bilayers. Moreover, we have observed the enlargement in a large number of nominally identical graphene devices and therefore we can rule out the possibility of device- or flake-specific features in the electroburning process. An alternative explanation was proposed by Lu et al. (20), who observed the enlargement in few-layer graphene nanoconstrictions fabricated using TEM. They attributed the enlargement to an improvement in the quality of few-layer graphene due to current annealing, which was simply ruled out by our experiments on electroburnt single-layer graphene. They also attributed this to the reduction of the edge scattering due to the orientation of the edges (i.e., zigzag edges). However, such edge effects have been ruled out by the TEM images of Barreiro et al. (19). Therefore, although this enlargement appears to be a common feature of graphene nanojunctions, so far the origin of the increase remains unexplained.In what follows, our aim is to demonstrate that such conductance enlargement is a universal feature of electroburnt graphene junctions and arises from QI at the moment of breaking. Graphene provides an ideal platform for studying room-temperature QI effects (21) because, as well as being a suitable material for contacting single molecules, it can serve as a natural 2D grid of interfering pathways. By electroburning a graphene junction to the point where only a few carbon bonds connect the left and right electrodes, one can study the effect of QI in ring- and chain-like structures that are covalently bonded to the electrodes. In this paper, we perform feedback-controlled electroburning on single-layer graphene nanojunctions and confirm that there is an increase in conductance immediately before the formation of the tunnel junction. Transport calculations for a variety of different atomic configurations using the nonequilibrium Green’s function (NEGF) method coupled to density functional theory (DFT) show a similar behavior. To elucidate the origin of the effect, we provide a model for the observed increase in the conductance based on the transition from multipath connectivity to single-path connectivity, in close analogy to an optical double-slit experiment. The model suggests that the conductance increase is likely to occur whenever junctions are formed from any sp²-bonded material.     

Detection rate of fluorine‐18‐fluorodeoxyglucose positron emission tomography in patients with marginal zone lymphoma of MALT type: a meta‐analysis

The aim of this article is to meta‐analyse published data about the detection rate (DR) of fluorine‐18‐fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the evaluation of patients with marginal zone lymphoma of the mucosa‐associated lymphoid tissue (MALT). A comprehensive literature search of studies published through February 2014 was performed. Pooled DR of ¹⁸F‐FDG PET or PET/CT including 95% confidence intervals (95% CI) was calculated on a per‐patient‐based analysis. Twenty studies including 376 patients with MALT lymphoma were selected. The pooled DR of ¹⁸F‐FDG PET or PET/CT was 71% (95% CI: 61–80%). A significant difference between the DR of PET/CT (69%; 95% CI: 61–80%) and that of PET alone (73%; 95% CI: 60–84%) was not demonstrated. A better DR of ¹⁸F‐FDG PET or PET/CT in bronchial (94%; 95% CI: 85–99%) and head‐and‐neck (90%; 95% CI: 78–98%) MALT lymphomas compared with gastric (62%; 95% CI: 46–77%) and ocular (49%; 95% CI: 36–63%) MALT lymphomas was found. This meta‐analysis demonstrates that MALT lymphoma is an ¹⁸F‐FDG‐avid tumour in most of the cases, suggesting a potential clinical role of ¹⁸F‐FDG PET or PET/CT in the initial evaluation of these patients. In particular, the DR of ¹⁸F‐FDG PET or PET/CT is related to the primary site of the MALT lymphoma. Copyright © 2014 John Wiley & Sons, Ltd.     

Nanocomposite of hydrophobic cellulose aerogel/graphene quantum dot/Pd: synthesis,characterization, and catalytic application

Novel hydrophobic cellulose aerogel (CA) supported graphene quantum dots (GQD)/Pd were synthesized with high lipophilicity, superior porosity as well as high catalytic activity. The nanocomposite aerogel was obtained in four steps, including transformation of cotton to CA, a silanization reaction of CA in the presence of TiO₂ nanoparticles to give polysiloxane/TiO₂ nanoparticles supported on CA (ST@CA), a modification of ST@CA with GQD to yield polysiloxane/TiO₂ nanoparticles/graphene quantum dots supported on CA (STG@CA), and finally a deposition of Pd nanoparticles on STG@CA. The synthesized aerogel demonstrated hydrophobicity with a water contact angle of 136.2°. It also exhibited excellent oil/water selective absorption capacity with an oil absorption of up to 79 g g⁻¹ with 134 g g⁻¹ selectivity. Finally, the nanocomposite was used as a heterogeneous catalyst in the oxidation reaction of alcohols, ethylbenzene, and alkenes. High yields, excellent selectivities, green and mild reaction conditions, recyclability and biocompatibility of the catalyst were important features of the reactions.

Novel hydrophobic cellulose aerogel (CA) supported graphene quantum dots (GQD)/Pd were synthesized with high lipophilicity, superior porosity as well as high catalytic activity.     

Bremsstrahlung parameters of praseodymium-142 in different human tissues: a dosimetric perspective for 142Pr radionuclide therapy

Objective

Praseodymium-142 [T _1/2?=?19.12?h, $ E_{\beta^{-}}$ ?=?2.162?MeV (96.3%), E???=?1575?keV (3.7%)] is one of the ¹⁴¹Pr radioisotopes. Many studies have been attempted to assess the significance of usage ¹⁴²Pr in radionuclide therapy. In many studies, the dosimetric parameters of ¹⁴²Pr sources were calculated by modeling ¹⁴²Pr sources in the water phantom and scoring the energy deposited around it. However, the medical dosimetry calculations in water phantom consider Bremsstrahlung production, raising the question: ??How important is to simulate human tissues instead of using water phantom??? This study answers these questions by estimation of ¹⁴²Pr Bremsstrahlung parameters.

Methods

The Bremsstrahlung parameters of ¹⁴²Pr as therapeutic beta nuclides in different human tissues (adipose, blood, brain, breast, cell nucleus, eye lens, gastrointestinal tract, heart, kidney, liver, lung deflated, lymph, muscle, ovary, pancreas, cartilage, red marrow, spongiosa, yellow marrow, skin, spleen, testis, thyroid and different skeleton bones) were calculated by extending the national council for radiation protection model. The specific Bremsstrahlung constant (?? _Br), probability of energy loss by beta during Bremsstrahlung emission (P _Br) and Bremsstrahlung activity (A _release)_Br were estimated. It should be mentioned that Monte Carlo simulation was used for estimation of ¹⁴²Pr Bremsstrahlung activity based on the element compositions of different human tissues and the calculated exposures from the anthropomorphic phantoms.

Results

?? _Br for yellow marrow was smallest amount (1.1962?×?10^?3 C/kg-cm²/MBq-h) compared to the other tissues and highest for cortical bone (2.4764?×?10^?3 C/kg-cm²/MBq-h), and, overall, ?? _Br for skeletal tissues were greater than other tissues. In addition, ?? _Br breast was 1.8261?×?10^?3 C/kg-cm²/MBq-h which was greater than sacrum and spongiosa bones. Moreover, according to (A _release)_Br of ¹⁴²Pr, the patients receiving ¹⁴²Pr do not have to be hospitalized for radiation precautions and the Bremsstrahlung production does not prevent the therapy for outpatients.

Conclusion

However, modeling ¹⁴²Pr source in water phantom for simulation of ¹⁴²Pr source in soft tissues could be acceptable due to similarity of ?? _Br in water and soft tissues; this approximation is a gross computation in the mediums encompassing high atomic numbers. These data may be practical in the investigation of Bremsstrahlung absorbed dose where ¹⁴²Pr is involved in radionuclide therapy.     

Reliability of a patient survey assessing ＂Short Form Injury Questionnaire 7＂ in Iran

Objective: Injury is a major cause of morbidity and mortality in the world.The assessment of patterns and severity of injury in high-risk groups is crucial for planning and service development.On a lar...     

Clinical and obstetric characteristics of pregnant women with Covid-19: A case series study on 26 patients

ObjectiveTo evaluate the clinical characteristics and outcomes of pregnant women with Covid-19.Materials and methodsThis case series study was performed to investigate demographic, clinical and obstetric characteristics of 26 pregnant women with COVID-19 referring to a university hospital of Kashan during the epidemic of COVID-19 (March to May 2020).ResultsThe mean gestational age of the patients at admission and delivery was 31.8 ± 5.2 and 36.3 ± 3.4 weeks, respectively. The most common symptoms were fever (96.2%) followed by dyspnea and cough (30.8%). The findings of lung CT scan showed abnormalities confirming the pneumonia in 22 patients (84.6%). Cesarean section was performed in 69.2% of the mothers. The most common maternal–fetal outcome was preterm delivery (38%). Two mothers were transferred to the ICU due to deterioration in clinical condition and they underwent mechanical ventilation without any maternal death. The most common neonatal outcomes were prematurity (38%) and low birth weight (34.6%). No cases of confirmed COVID-19 were observed in the neonates.ConclusionClinical manifestations and laboratory and radiographic findings in pregnant women with COVID-19 are similar to the general population. Common outcomes of pregnancy and delivery in mothers included increased rate of preterm delivery and cesarean section. The most prevalent neonatal outcomes included prematurity and LBW. Careful monitoring of pregnant women with COVID-19 is recommended.