Measurement of the local Jahn-Teller distortion in LaMnO_3.006

The atomic pair distribution function (PDF) of stoichiometric LaMnO_3 has been measured. This has been fit with a structural model to extract the local Jahn-Teller distortion for an ideal Mn(3+)O_6 octahedron. These results are compared to Rietveld refinements of the same data which give the average structure. Since the local structure is being measured in the PDF there is no assumption of long-range orbital order and the real, local, Jahn-Teller distortion is measured directly. We find good agreement both with published crystallographic results and our own Rietveld refinements suggesting that in an accurately stoichiometric material there is long range orbital order as expected. The local Jahn-Teller distortion has 2 short, 2 medium and 2 long bonds.Comment: 5 pages, 3 postscript figures, minor change

Design of a freeform two-reflector system to collimate and shape a point source distribution

In this paper we propose a method to compute a freeform reflector system for collimating and shaping a beam from a point source. We construct these reflectors such that the radiant intensity of the source is converted into a desired target. An important generalization in our approach compared to previous research is that the output beam can be in an arbitrary direction. The design problem is approached by using a generalized Monge-Amp\`ere equation. This equation is solved using a least-squares algorithm for non-quadratic cost functions. This algorithm calculates the optical map, from which we can then compute the surfaces. We test our algorithm on two cases. First we consider a uniform source and target distribution. Next, we use the model of a laser diode light source and a ring-shaped target distribution

Management of prolonged first stage of labour in a low-resource setting: lessons learnt from rural Malawi

Background Caesarean sections without medical indication cause substantial maternal and perinatal ill-health, particularly in low-income countries where surgery is often less safe. In presence of adequate labour monitoring and by appropriate use of evidence-based interventions for prolonged first stage of labour, unnecessary caesarean sections can be avoided. We aim to describe the incidence of prolonged first stage of labour and the use of amniotomy and augmentation with oxytocin in a low-resource setting in Malawi. Methods Retrospective analysis of medical records and partographs of all women who gave birth in 2015 and 2016 in a rural mission hospital in Malawi. Primary outcomes were incidence of prolonged first stage of labour based on partograph tracings, caesarean section indications and utilization of amniotomy and oxytocin augmentation. Results Out of 3246 women who gave birth in the study period, 178 (5.2%) crossed the action line in the first stage of labour, of whom 21 (11.8%) received oxytocin to augment labour. In total, 645 women gave birth by caesarean section, of whom 241 (37.4%) with an indication 'prolonged first stage of labour'. Only 113 (46.9%) of them crossed the action line and in 71/241 (29.5%) membranes were still intact at the start of caesarean section. Excluding the 60 women with prior caesarean sections, 14/181 (7.7%) received oxytocin prior to caesarean section for augmentation of labour. Conclusion The diagnosis prolonged first stage of labour was often made without being evident from labour tracings and two basic obstetric interventions to prevent caesarean section, amniotomy and labour augmentation with oxytocin, were underused.Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care

Nanosized Sodium-Doped Lanthanum Manganites: Role of the Synthetic Route on their Physical Properties

In this paper we present the results of the synthesis and characterisation of nanocrystalline La1-xNaxMnO3+delta samples. Two synthetic routes were employed: polyacrylamide-based sol-gel and propellant synthesis. Pure, single phase materials were obtained with grain size around 35 nm for the sol-gel samples and around 55 nm for the propellant ones, which moreover present a more broaden grain size distribution. For both series a superparamagnetic behaviour was evidenced by means of magnetisation and EPR measurements with peculiar features ascribable to the different grain sizes and morphology. Preliminary magnetoresistivity measurements show enhanced low-field (< 1 T) magnetoresistance values which suggest an interesting applicative use of these manganites.Comment: 31 Pages 10 Figures to appear in Chem. Mate

Death receptor 5 is activated by fucosylation in colon cancer cells

The remarkable pro-apoptotic properties of tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) have led to considerable interest in this protein as a potential anticancer therapeutic. However, TRAIL is largely ineffective in inducing apoptosis in certain cancer cells, and the mechanisms underlying this selectivity are unknown. In colon adenocarcinomas, posttranslational modifications including O- and N- glycosylation of death receptors were found to correlate with TRAIL-induced apoptosis. Additionally, mRNA levels of fucosyltransferase 3 (FUT3) and 6 (FUT6) were found to be high in the TRAIL-sensitive colon adenocarcinoma cell line COLO 205. In this study, we use agonistic receptor-specific TRAIL variants to dissect the contribution of FUT3 and FUT6-mediated fucosylation to TRAIL-induced apoptosis via its two death receptors, DR4 and DR5. Triggering of apoptosis by TRAIL revealed that the low FUT3/6-expressing cells DLD-1 and HCT 116 are insensitive to DR5 but not to DR4-mediated apoptosis. By contrast, efficient apoptosis is mediated via both receptors in high FUT3/6-expressing COLO 205 cells. The reconstitution of FUT3/6 expression in DR5-resistant cells completely restored TRAIL sensitivity via this receptor, while only marginally enhancing apoptosis via DR4 at lower TRAIL concentrations. Interestingly, we observed that induction of the salvage pathway by external administration of l-fucose restores DR5-mediated apoptosis in both DLD-1 and HCT 116 cells. Finally, we show that fucosylation influences the ligand-independent receptor association that leads to increased death inducing signalling complex (DISC) formation and caspase-8 activation. Taken together, these results provide evidence for the differential impact of fucosylation on signalling via DR4 or DR5. These findings provide novel opportunities to enhance TRAIL sensitivity in colon adenocarcinoma cells that are highly resistant to DR5-mediated apoptosis

Spin-wave scattering at low temperatures in manganite films

The temperature $T$ and magnetic field $H$ dependence of the resistivity $\rho$ has been measured for La$_{0.8-y}$Sr$_{0.2}$MnO$_{3}$ (y=0 and 0.128) films grown on (100) SrTiO$_{3}$ substrates. The low-temperature $\rho$ in the ferromagnetic metallic region follows well $\rho (H,T)=\rho _{0}(H)+A(H)\omega_{s}/\sinh (\hbar \omega_{s}/2k_{B}T)+B(H)T^{7/2}$ with $\rho _{0}$ being the residual resistivity. We attribute the second and third term to small-polaron and spin-wave scattering, respectively. Our analysis based on these scattering mechanisms also gives the observed difference between the metal-insulator transition temperatures of the films studied. Transport measurements in applied magnetic field further indicate that spin-wave scattering is a key transport mechanism at low temperatures.Comment: 5 pages, 4 figures. to appear in Phys. Rev.

Association of Timing of Plasma Transfusion With Adverse Maternal Outcomes in Women With Persistent Postpartum Hemorrhage

IMPORTANCE Early plasma transfusion for women with severe postpartum hemorrhage (PPH) is recommended to prevent coagulopathy. However, there is no comparative, quantitative evidence on the association of early plasma transfusion with maternal outcomes. OBJECTIVE To compare the incidence of adverse maternal outcomes among women who received plasma during the first 60 minutes of persistent PPH vs women who did not receive plasma for similarly severe persistent PPH. DESIGN, SETTING, AND PARTICIPANTS This multicenter cohort study used a consecutive sample of women with persistent PPH, defined as PPH refractory to first-line measures to control bleeding, between January 1, 2011, and January 1, 2013. Time-dependent propensity score matching was used to select women who received plasma during the first 60 minutes of persistent PPH and match each of them with a woman who had shown the same severity and received the same treatment of PPH but who had not received plasma at the moment of matching. Transfusions were not guided by coagulation tests. Statistical analysis was performed from June 2018 to June 2019. EXPOSURES Transfusion of plasma during the first 60 minutes of persistent PPH vs no or later plasma transfusion. MAIN OUTCOMES AND MEASURES Incidence of adverse maternal outcomes, defined as a composite of death, hysterectomy, or arterial embolization. RESULTS This study included 1216 women (mean [SD] age, 31.6 [5.0] years) with persistent PPH, of whom 932 (76.6%) delivered vaginally and 780 (64.1%) had PPH caused by uterine atony. Seven women (0.6%) died because of PPH, 62 women (5.1%) had a hysterectomy, and 159 women (13.1%) had arterial embolizations. Among women who received plasma during the first 60 minutes of persistent PPH, 114 women could be matched with a comparable woman who had not received plasma at the moment of matching. The incidence of adverse maternal outcomes was similar between the women, with adverse outcomes recorded in 24 women (21.2%) who received early plasma transfusion and 23 women (19.9%) who did not receive early plasma transfusion (odds ratio, 1.09; 95% CI, 0.57-2.09). Results of sensitivity analyses were comparable to the primary results. CONCLUSIONS AND RELEVANCE In this cohort study, initiation of plasma transfusion during the first 60 minutes of persistent PPH was not associated with adverse maternal outcomes compared with no or later plasma transfusion, independent of severity of PPH

Predictors of HIV Among 1 Million Clients in High-Risk Male Populations in Tanzania

The World Health Organization identified men as an essential group to target with HIV testing and treatment strategies;: men who have sex with men (MSM) and male clients of female sex workers (CFSW) account for 35% of new HIV infections globally. Using a cross-sectional design from a community-based HIV prevention project in Tanzania (October 2015-September 2018) and multivariable logistic regression, we identified predictors of HIV seropositivity among men. Of 1,041,343 men on their initial visit to the project, 36,905 (3.5%) were MSM; 567,005 (54.5%) were CFSW; and 437,343 (42.0%) were other men living near hotspots (OMHA). Three predictors of HIV seropositivity emerged across all three groups: being uncircumcised, having sexually transmitted infection symptoms, and harmful drinking of alcohol before sex. Any reported form of gender-based violence among MSM and OMHA and inconsistent condom use among CFSW were associated with HIV seropositivity. These findings may inform community HIV strategies like self-testing, delivery of pre-exposure prophylaxis and antiretroviral therapy, and behavioral change communication targeting men at higher risk of infection

Strain effect on electronic transport and ferromagnetic transition temperature in La0.9_{0.9}Sr0.1_{0.1}MnO3_{3} thin films

We report on a systematic study of strain effects on the transport properties and the ferromagnetic transition temperature $T_{c}$ of high-quality La$_{0.9}$Sr$_{0.1}$MnO$_{3}$ thin films epitaxially grown on (100) SrTiO$_{3}$ substrates. Both the magnetization and the resistivity are critically dependent on the film thickness. $T_{c}$ is enhanced with decreasing the film thickness due to the compressive stain produced by lattice mismatch. The resistivity above 165 K of the films with various thicknesses is consistent with small polaronic hopping conductivity. The polaronic formation energy $E_{P}$ is reduced with the decrease of film thickness. We found that the strain dependence of $T_{c}$ mainly results from the strain-induced electron-phonon coupling. The strain effect on $E_{P}$ is in good agreement with the theoretical predictions.Comment: 6 pages and 5 figures, accepted for publication in Phys. Rev.

Randomised trial of a decision aid and its timing for women being tested for a BRCA1/2 mutation

Contains fulltext : 57882.pdf (publisher's version ) (Closed access)The aim of the study was to evaluate the impact of a decision aid (DA) and its timing in women being tested for a BRCA1/2 mutation. Women with and without a previous history of cancer were included after blood sampling for genetic testing. The DA consisted of a brochure and video providing information on screening and prophylactic surgery. To evaluate the impact of the DA, women were randomised to the DA group (n=184), receiving the DA 2 weeks after blood sampling, or to the control group (n=184). To evaluate the impact of timing, mutation carriers who had received the DA before the test result (n=47) were compared to mutation carriers who received the DA after the test result (n=42). Data were collected on well-being, treatment choice, decision and information related outcomes. The impact of the DA was measured 4 weeks after blood sampling. The impact of timing was measured 2 weeks after a positive test result. The DA had no impact on well-being. Regarding decision related outcomes, the DA group more frequently considered prophylactic surgery (P=0.02) corroborated with higher valuations (P=0.04). No differences were found for the other decision related outcomes. Regarding information related outcomes, the DA group felt better informed (P=0.00), was more satisfied with the information (P=0.00), and showed more accurate risk perceptions. Timing of the DA had no effect on any of the outcomes. No interactions were found between the DA and history of cancer. In conclusion, women being tested for a BRCA1/2 mutation benefit from the DA on information related outcomes. Because timing had no effect, the DA is considered useful either before or after the test result