Blue, green and yellow carbon dots derived from pyrogenic carbon: Structure and fluorescence behaviour

Fluorescence lifetimes and quantum yields featuring polycyclic aromatic hydrocarbons (PAHs) and other organics constituting pyrogenic carbon particulate matter (PM) are seldom measured. In this work, PM sampled in a fuel-rich ethylene flame was firstly separated in organic carbon (OC), soluble in dichloromethane, and refractory organic carbon (ROC), soluble in N-methyl pyrrolidinone, and then analyzed by size exclusion chromatography (SEC) coupled with online UV and fluorescence detection, and by offline fluorescence spectroscopy and mass spectrometry. It was found that three classes of differently light emitting carbon dots (CDs) could be bottom-up synthesized in the same flame system by selecting appropriately the residence time. Actually, OC presented blue fluorescence regardless the residence time, whereas ROC sampled at low and high residence time emitted fluorescence in the green (green CDs) and in the yellow (yellow CDs) region, respectively. The SEC molecular weight of all CDs presented similar trimodal distributions, centered around 300, 1000 and 10,000 u. For the first time fluorescence lifetimes and quantum yields of pyrogenic CD fractions were measured as additional parameters useful for discriminating the fluorescent components and inferring their structural properties, with the support of mass spectrometry. The different spectroscopic features of CDs could be associated to different compositional characteristics as the polydispersity of molecular components featuring blue CDs, opposed to the oligomer-like nature of green and yellow CDs. Pyrogenic CDs showed different fluorescence emission ranges, quantum yield and lifetimes, appealing for their possible applications in the fields of imaging, electronics and sensors

PAHs and fullerenes as structural and compositional motifs tracing and distinguishing organic carbon from soot

Examining the features distinguishing organic carbon from soot is crucial for understanding the source, the effect on the environment and their respective role in aerosol chemistry and soot formation. Beside to the obvious PAH picking-out in the low-mass mode (C number 40) of organic carbon, separated by carbon particulate matter extraction from young and mature soot thermophoretically sampled in premixed flames, was done by laser-desorption-time-of-flight mass spectrometry, exploiting the laser power increase. The perusal of organic carbon mass spectra through mathematical tools in comparison to aromatic and alkyl-substituted PAH-laden samples and the persistence of high-mass mode at high laser power led to exclude the contribution of dimers and alkyl-bridged PAHs attributing the second mode to both fully-benzenoid and cyclopenta-PAHs. Profound differences between mass spectra of organic carbon and soot were noticed as neither molecules nor radicals of PAHs could be drawn out from soot, even at high laser power, and only small radicals and carbon clusters like fullerenes were observed, especially for young soot. These inferences evidenced the importance of analysing separately organic carbon and soot especially if insights into soot particles nucleation are to be obtained. In the case of benzene flame, already at the inception, soot consists of strongly tangled aromatic motifs crosslinked each other, presumably deriving from reactive coagulation/clustering of relatively small aromatic hydrocarbons/radicals early formed. In methane and ethylene flames, coalesced liquid-like material composed of soot and PAHs is formed and transformed later on undergoing some carbonization and molecular growth, respectively

The (Mis)Reporting of Male Circumcision Status among Men and Women in Zambia and Swaziland: A Randomized Evaluation of Interview Methods

BACKGROUND: To date, male circumcision prevalence has been estimated using surveys of men self-reporting their circumcision status. HIV prevention trials and observational studies involving female participants also collect data on partners' circumcision status as a risk factor for HIV/STIs. A number of studies indicate that reports of circumcision status may be inaccurate. This study assessed different methods for improving self- and partner reporting of circumcision status. METHODS/FINDINGS: The study was conducted in urban and rural Zambia and urban Swaziland. Men (N = 1264) aged 18-50 and their female partners (N = 1264), and boys (N = 840) aged 13-17 were enrolled. Participants were recruited from HIV counseling and testing sites, health centers, and surrounding communities. The study experimentally assessed methods for improving the reporting of circumcision status, including: a) a simple description of circumcision, b) a detailed description of circumcision, c) an illustration of a circumcised and uncircumcised penis, and d) computerized self-interviewing. Self-reports were compared to visual examination. For men, the error in reporting was largely unidirectional: uncircumcised men more often reported they were circumcised (2-7%), depending on setting. Fewer circumcised men misrepresented their status (0.05-5%). Misreporting by women was significantly higher (11-15%), with the error in both directions. A sizable number of women reported that they did not know their partner's circumcision status (3-8%). Computerized interviewing did not improve accuracy. Providing an illustration, particularly for illiterate participants, significantly improved reporting of circumcision status, decreasing misreporting among illiterate participants from 13% to 10%, although misreporting was not eliminated. CONCLUSIONS: Study results suggest that the prevalence of circumcision may be overestimated in Zambia and Swaziland; the error in reporting is higher among women than among men. Improved reporting when a description or illustration is provided suggests that the source of the error is a lack of understanding of male circumcision

Optical Properties of Organic Carbon and Soot Produced in an Inverse Diffusion Flame

The carbonaceous matter (soot plus organic carbon) sampled downstream of an ethylene inverse diffusion flame (IDF) was chemically and spectroscopically analyzed in detail. In particular, the H/C ratio, the UV-Visible absorption coefficient and Raman parameters were measured and found to be representative of a highly disordered sp2 -rich carbon as the early soot sampled in a premixed flame. In contrast, the optical band gap was found to be relatively low (0.7eV), closer to the optical band gap of graphite than to that of medium-sized polycyclic aromatic hydrocarbons (\u3e2eV) which are widely considered to be soot precursors and are mostly contained in the organic carbon. The significance of the optical band gap as signature of different structural levels (nano-, micro- and macro-structure) of sp2 -rich aromatic disordered carbons was critically analyzed in reference to their molecular weight/size distribution. The relevance of the optical band analysis to the study of the soot formation mechanism was also highlighted

Assortative human pair-bonding for partner ancestry and allelic variation of the dopamine receptor D4 (DRD4) gene

The 7R allele of the dopamine receptor D4 gene has been associated with attention-deficit hyperactivity disorder and risk taking. On the cross-population scale, 7R allele frequencies have been shown to be higher in populations with more of a history of long-term migrations. It has also been shown that the 7R allele is associated with individuals having multiple-ancestries. Here we conduct a replication of this latter finding with two independent samples. Measures of subjects’ ancestry are used to examine past reproductive bonds. The individuals’ history of inter-racial/ancestral dating and their feelings about this are also assessed. Tentative support for an association between multiple ancestries and the 7R allele were found. These results are dependent upon the method of questioning subjects about their ancestries. Inter-racial dating and feelings about inter-racial pairing were not related to the presence of the 7R allele. This might be accounted for by secular trends that might have substantively altered the decision-making process employed when considering relationships with individuals from different groups. This study provides continued support for the 7R allele playing a role in migration and/or mate choice patterns. However, replications and extensions of this study are needed and must carefully consider how ancestry/race is assessed

Effects of losartan treatment on cardiac autonomic control during volume loading in patients with DCM

This study evaluated the effect of angiotensin II receptor blockade on cardiac autonomic control adaptation and urine output in response to acute isotonic volume load in patients with idiopathic dilated cardiomyopathy (DCM) and asymptomatic to mildly symptomatic heart failure. Left ventricular volumes and heart rate variability measurements were assessed at baseline and during intravenous saline load in 14 patients before and after 2 mo of losartan treatment. After losartan treatment, blood pressure values were lower, whereas left ventricular ejection fraction was higher (F = 79, P50 ms) decreased during saline load in untreated patients (F = 3.1, P< 0.05 and F = 6.5, P< 0.01, respectively), but not after losartan. Similarly, a decrease in very low frequency (F = 3.2, P< 0.05), low-frequency (F = 2.9, P< 0.05), and high-frequency power (F = 6.1, P< 0.01) after saline load was observed only in untreated patients. In patients with DCM, losartan treatment improves the cardiac autonomic adaptation and increases urine output in response to volume overload

Received cradling bias during the first year of life: A retrospective study on children with typical and atypical development

A population-level left cradling bias exists whereby 60-90% of mothers hold their infants on the left side. This left biased positioning appears to be mutually beneficial to both the mother and the baby’s brain organization for processing of socio-emotional stimuli. Previous research connected cradling asymmetries and Autism Spectrum Disorders (ASD), entailing impairment in socio- communicative relationships and characterized by an early hypo-lateralization of brain functions. In this explorative study, we aimed to provide a contribution to the retrospective investigations by looking for early behavioral markers of neurodevelopmental disorders such as ASD. We hypothesized that an atypical trajectory in maternal cradling might be one of the possible signs of an interference in mother-infant socio-emotional communication, and thus of potential neurodevelopmental dysfunctions. To this aim, we examined photos depicting mother-child early cradling interactions by consulting family albums of 27 children later diagnosed with autism and 63 typically developing children. As regards the first half of the first year of life, no differences were shown between maternal cradling-side preferences in typical and ASD groups, both exhibiting the left-cradling bias in the 0-3 months period, but not in the 3-6 months period. However, our results show dissimilar patterns of cradling preferences during the second half of the first year of life. In particular, the absence of left-cradling shown in typical mothers was not observed in ASD mothers, who exhibited a significant left-cradling bias in the 6-12 months age group. This difference might reflect the fact that mother-infant relationship involving children later diagnosed with ASD might remain “basic” because mothers experience a lack of social activity in such children. Alternatively, it may reflect the overstimulation in which mothers try to engage infants in response to their lack of responsiveness and social initiative. However, further investigations are needed both to distinguish between these two possibilities and to define the role of early typical and reversed cradling experiences on neurodevelopment

Prone versus supine position for adjuvant breast radiotherapy: a prospective study in patients with pendulous breasts.

Purpose: To analyze dosimetric parameters of patients receiving adjuvant breast radiotherapy (RT) in the prone versus supine position. Methods and materials: Forty-one out of 55 patients with pendulous breasts and candidates for adjuvant RT were enrolled in the study after informed consent. They underwent computed tomography (CT)-simulation in both prone and supine position. Target and non target volumes were outlined on CT images. Prescribed dose was 50 Gy delivered by two tangential photon fields followed by 10 Gy electron boost. Target coverage and dose homogeneity to clinical target volume (CTV) and planning target volume (PTV) were assessed by V95, V105 and V107 and dose to lung, heart and left anterior descending coronary artery (LAD) by V5, V10, V20, and mean and maximum dose. Data were analyzed by Student\u2019s t-test. Results: CTV and PTV coverage was significantly better in supine than in prone position. Lung V5, V10, and V20 were significantly lower in prone than in supine position. Heart V5, V10, V20, and LAD mean and maximum dose, in the 17 patients with left breast tumor, were lower in prone than in supine position, but without statistical significance. Based on treatment planning data and on treatment feasibility, 29/41 patients (70.7%) were treated in prone position. Acute and late toxicities of patients treated in prone and in supine position were not statistically different. Conclusion: Prone position is a favorable alternative for irradiation of mammary gland in patients with pendulous breasts and in our series was adopted in 71% of the cases

Rapid identification of BCR/ABL1-like acute lymphoblastic leukaemia patients using a predictive statistical model based on quantitative real time-polymerase chain reaction: clinical, prognostic and therapeutic implications.

BCR/ABL1-like acute lymphoblastic leukaemia (ALL) is a subgroup of B-lineage acute lymphoblastic leukaemia that occurs within cases without recurrent molecular rearrangements. Gene expression profiling (GEP) can identify these cases but it is expensive and not widely available. Using GEP, we identified 10 genes specifically overexpressed by BCR/ABL1-like ALL cases and used their expression values - assessed by quantitative real time-polymerase chain reaction (Q-RT-PCR) in 26 BCR/ABL1-like and 26 non-BCR/ABL1-like cases to build a statistical "BCR/ABL1-like predictor", for the identification of BCR/ABL1-like cases. By screening 142 B-lineage ALL patients with the "BCR/ABL1-like predictor", we identified 28/142 BCR/ABL1-like patients (19·7%). Overall, BCR/ABL1-like cases were enriched in JAK/STAT mutations (P < 0·001), IKZF1 deletions (P < 0·001) and rearrangements involving cytokine receptors and tyrosine kinases (P = 0·001), thus corroborating the validity of the prediction. Clinically, the BCR/ABL1-like cases identified by the BCR/ABL1-like predictor achieved a lower rate of complete remission (P = 0·014) and a worse event-free survival (P = 0·0009) compared to non-BCR/ABL1-like ALL. Consistently, primary cells from BCR/ABL1-like cases responded in vitro to ponatinib. We propose a simple tool based on Q-RT-PCR and a statistical model that is capable of easily, quickly and reliably identifying BCR/ABL1-like ALL cases at diagnosis