Conservative management of preterm premature rupture of membranes beyond 32 weeks' gestation: is it worthwhile?

We aimed to investigate whether conservative management of preterm premature rupture of membranes (PPROM) at 32-34 weeks' gestation improves outcome. In this retrospective analysis of singleton pregnancies, the study group included patients with PPROM at 28-34 weeks' gestation and the control group included patients presented with spontaneous preterm delivery at 28-34 weeks' gestation. Both groups were subdivided according to gestational age - early (28-31 weeks' gestation) versus late (32-34 weeks' gestation). Adverse neonatal outcome included neonatal death, intraventricular haemorrhage grade 3/4, respiratory distress syndrome, periventricular leucomalacia and neonatal sepsis. The study and control groups included 94 and 86 women, respectively. The study group had a lower incidence of adverse neonatal outcome at the earlier weeks (28-31), compared with the control group at the same gestational age. In contrast, at 32-34 weeks' gestation no difference in the risk for adverse neonatal outcome was noticed. Additionally, within the study group, chorioamnionitis rate was significantly higher among those who delivered at 32-34 weeks' gestation (p < 0.01). No advantage for conservative management of PPROM was demonstrated beyond 31 weeks' gestation. Moreover, conservative management of PPROM at 32-34 weeks' gestation may expose both mother and neonate to infectious morbidity.

Multiple lineages of Avian malaria parasites (Plasmodium) in the Galapagos Islands and evidence for arrival via migratory birds.

Haemosporidian parasites in the genus Plasmodium were recently detected through molecular screening in the Galapagos Penguin (Spheniscus mendiculus). We summarized results of an archipelago-wide screen of 3726 endemic birds representing 22 species for Plasmodium spp. through a combination of molecular and microscopy techniques. Three additional Plasmodium lineages were present in Galapagos. Lineage A-infected penguins, Yellow Warblers (Setophaga petechia aureola), and one Medium Ground Finch (Geospiza fortis) and was detected at multiple sites in multiple years [corrected]. The other 3 lineages were each detected at one site and at one time; apparently, they were transient infections of parasites not established on the archipelago. No gametocytes were found in blood smears of infected individuals; thus, endemic Galapagos birds may be dead-end hosts for these Plasmodium lineages. Determining when and how parasites and pathogens arrive in Galapagos is key to developing conservation strategies to prevent and mitigate the effects of introduced diseases. To assess the potential for Plasmodium parasites to arrive via migratory birds, we analyzed blood samples from 438 North American breeding Bobolinks (Dolichonyx oryzivorus), the only songbird that regularly migrates through Galapagos. Two of the ephemeral Plasmodium lineages (B and C) found in Galapagos birds matched parasite sequences from Bobolinks. Although this is not confirmation that Bobolinks are responsible for introducing these lineages, evidence points to higher potential arrival rates of avian pathogens than previously thought. Linajes Múltiples de Parásitos de Malaria Aviar (Plasmodium) en las Islas Galápagos y Evidencia de su Arribo por Medio de Aves Migratorias.

Ultimate bending strength of Si nanowires.

Test platforms for the ideal strength of materials are provided by almost defect-free nanostructures (nanowires, nanotubes, nanoparticles, for example). In this work, the ultimate bending strengths of Si nanowires with radii in the 20-60 nm range were investigated by using a new bending protocol. Nanowires simply held by adhesion on flat substrates were bent through sequential atomic force microscopy manipulations. The bending states prior to failure were analyzed in great detail to measure the bending dynamics and the ultimate fracture strength of the investigated nanowires. An increase in the fracture strengths from 12 to 18 GPa was observed as the radius of nanowires was decreased from 60 to 20 nm. The large values of the fracture strength of these nanowires, although comparable with the ideal strength of Si, are explained in terms of the surface morphology of the nanowires.

Placenta/birthweight ratio and perinatal outcome: a retrospective cohort analysis.

OBJECTIVE: The placenta weight/birthweight (PW/BW) ratio has been shown to be associated with certain long-term fetal outcomes; however, its association with short-term outcomes has not received much attention. Our aim was to assess the correlation between the PW/BW ratio and short-term adverse obstetrics outcomes in full-term, appropriate-for-gestational-age (AGA) newborns. DESIGN: Retrospective cohort study analysis using data from the McGill Obstetrical and Neonatal Database. SETTING: McGill University Health Centre in Montreal Canada. POPULATION: AGA neonates. METHODS: Three groups of full-term AGA neonates were created, according to their PW/BW ratio (high, normal and low), to be compared. Our primary outcome was the admission rate to the neonatal intensive care unit (NICU), and secondary outcomes included an Apgar score < 7 at 5 minutes, cord PH < 7.0, cord base excess (BE) ≤ 12, respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), occurrence of apnoea episodes, breech presentation at delivery, caesarean section rate and status in discharge home. A logistic regression model was instituted to investigate the predictors for adverse obstetrics outcomes. MAIN OUTCOME MEASURE: Admission to the NICU. RESULTS: Compared with the group with normal PW/BW ratios, the high PW/BW ratio group was associated with increased rates of admission to the NICU, of Apgar scores < 7 at 5 minutes, of breech presentation and caesarean section. On the contrary, the low PW/BW ratio group showed decreased rates of NICU admission, breech presentation and caesarean section. CONCLUSIONS: A high PW/BW ratio is significantly correlated with short-term adverse perinatal outcomes. This ratio may be used as a new and simple warning sign to predict the possibility of short-term health risks for newborns.

Visualization of silicone gel in human breast tissue using new infrared imaging spectroscopy.

Between 1 and 2 million women in the United States have silicone breast implants. Complications include capsular contracture and calcification and possibly connective tissue diseases such as scleroderma and rheumatoid arthritis, a subject of some controversy. In order to accurately assess the role of silicone in any histopathologic change, it is necessary to confirm its presence and to identify other foreign materials in the capsular tissue. Although light microscopy is used to visualize regions of tissue containing foreign inclusions, their chemical identity can only be determined using analytical techniques such as infrared or Raman microscopy. However, these conventional microprobe techniques record spectra only at single points and require an a priori knowledge of the locations of the inclusion to be probed. To significantly extend the capabilities of both infrared spectroscopy and optical microscopy, we have developed a new infrared imaging system that completely integrates these two methods. In this manuscript we highlight the ability of the technique to screen rapidly and to determine accurately the presence, size and chemical composition of silicone gel inclusions in human breast tissue.

The fingerprint of the 2018 drought in Europe on ground-based atmospheric CO2 measurements.

During the summer of 2018, a widespread drought developed over Northern and Central Europe. The increase in temperature and the reduction of soil moisture have influenced carbon dioxide (CO2) exchange between the atmosphere and terrestrial ecosystems in various ways, such as a reduction of photosynthesis, changes in ecosystem respiration, or allowing more frequent fires. In this study, we characterize the resulting perturbation of the atmospheric CO2 seasonal cycles. 2018 has a good coverage of European regions affected by drought, allowing the investigation of how ecosystem flux anomalies impacted spatial CO2 gradients between stations. This density of stations is unprecedented compared to previous drought events in 2003 and 2015, particularly thanks to the deployment of the Integrated Carbon Observation System (ICOS) network of atmospheric greenhouse gas monitoring stations in recent years. Seasonal CO2 cycles from 48 European stations were available for 2017 and 2018. Earlier data were retrieved for comparison from international databases or national networks. Here, we show that the usual summer minimum in CO2 due to the surface carbon uptake was reduced by 1.4 ppm in 2018 for the 10 stations located in the area most affected by the temperature anomaly, mostly in Northern Europe. Notwithstanding, the CO2 transition phases before and after July were slower in 2018 compared to 2017, suggesting an extension of the growing season, with either continued CO2 uptake by photosynthesis and/or a reduction in respiration driven by the depletion of substrate for respiration inherited from the previous months due to the drought. For stations with sufficiently long time series, the CO2 anomaly observed in 2018 was compared to previous European droughts in 2003 and 2015. Considering the areas most affected by the temperature anomalies, we found a higher CO2 anomaly in 2003 (+3 ppm averaged over 4 sites), and a smaller anomaly in 2015 (+1 ppm averaged over 11 sites) compared to 2018. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

Regional 14CO2 offsets in the troposphere: magnitude, mechanisms, and consequences.

Radiocarbon dating methods typically assume that there are no significant tropospheric (14)CO(2) gradients within the low- to mid-latitude zone of the Northern Hemisphere. Comparison of tree ring (14)C data from southern Germany and Anatolia supports this assumption in general but also documents episodes of significant short-term regional (14)CO(2) offsets. We suggest that the offset is caused by an enhanced seasonal (14)CO(2) cycle, with seasonally peaked flux of stratospheric (14)C into the troposphere during periods of low solar magnetic activity, coinciding with substantial atmospheric cooling. Short-term episodes of regional (14)CO(2) offsets are important to palaeoclimate studies and to high-resolution archaeological dating.

Local atomic order and hierarchical polar nanoregions in a classical relaxor ferroelectric.

The development of useful structure-function relationships for materials that exhibit correlated nanoscale disorder requires adequately large atomistic models which today are obtained mainly via theoretical simulations. Here, we exploit our recent advances in structure-refinement methodology to demonstrate how such models can be derived directly from simultaneous fitting of 3D diffuse- and total-scattering data, and we use this approach to elucidate the complex nanoscale atomic correlations in the classical relaxor ferroelectric PbMg1/3Nb2/3O3 (PMN). Our results uncover details of ordering of Mg and Nb and reveal a hierarchical structure of polar nanoregions associated with the Pb and Nb displacements. The magnitudes of these displacements and their alignment vary smoothly across the nanoregion boundaries. No spatial correlations were found between the chemical ordering and the polar nanoregions. This work highlights a broadly applicable nanoscale structure-refinement method and provides insights into the structure of PMN that require rethinking its existing contentious models.

[Surgical treatment for genital prolapse in the very elderly: a continuous series of 43 patients]. / Traitement chirurgical du prolapsus du quatrième âge. A propos d'une série continue de 43 cas.

OBJECTIVES: To evaluate surgical treatment for genital prolapse in patients over the age of 75. PATIENTS AND METHODS: This is a continuous retrospective series of 43 patients operated for genital prolapse between March 2001 and October 2006. Surgical outcomes in terms of anatomical correction as well as urological and proctological results were analyzed. Morbidity and mortality studies were carried out. A satisfaction and quality of life assessment was carried out among 19 patients (44%) by an independent researcher at a distance from the intervention. RESULTS: Morbidity attributable to the surgery was minimal, with no cases of mortality. Mean hospital stay was five days. Anatomical correction was good without troubling urological or proctological consequences. Two surgical options were compared: surgery with vaginal occlusion in 23 patients (53.5%) and vaginal conserving surgery in 20 patients (46.5%). Surgical outcomes and morbidity were equivalent in the two groups. Seventy-nine percent of patients surveyed at a distance from the interventions estimated that the procedure had improved their quality of life. DISCUSSION AND CONCLUSION: Surgical treatment for genital prolapse in the very elderly population is a reasonable therapeutic option. Postoperative evaluation demonstrates good anatomical as well as functional results in the majority of cases.

Prevention of potential errors in resuscitation medications orders by means of a computerised physician order entry in paediatric critical care.

INTRODUCTION: Computerised physician order entry with clinical decision support system (CPOE+CDSS) is an important tool in attempting to reduce medication errors. The objective of this study was to evaluate the impact of a CPOE+CDSS on (1) the frequency of errors in ordering resuscitation (CPR) medications and (2) the time for printing out the order form, in a paediatric critical care department (PCCD). SETTING: An 18-bed PCCD in a tertiary-care children's hospital. DESIGN: Prospective cohort study. MEASURES: Compilation and comparison of number of errors and time to fill in forms before and after implementation of CPOE+CDSS. Time to fill in conventional, simulated and CPOE forms was measured and compared. RESULTS: There were three reported incidents of errors among 13,124 CPR medications orders during the year preceding implementation of CPOE+CDSS. These represent errors that escaped the triple check by three independent staff members. There were no errors after CPOE+CDSS was implemented (100% error reduction for 46,970 orders). Time to completion of drug forms dropped from 14 min 42 s to 2 min 14s (p < 0.001). CONCLUSIONS: CPOE+CDSS completely eliminated errors in filling in the forms and significantly reduced time to completing the form.

Coupling of emergent octahedral rotations to polarization in (K,Na)NbO3 ferroelectrics.

Perovskite potassium sodium niobates, K1-xNaxNbO3, are promising lead-free piezoelectrics. Their dielectric and piezoelectric characteristics peak near x = 0.5, but the reasons for such property enhancement remain unclear. We addressed this uncertainty by analyzing changes in the local and average structures across the x = 0.5 composition, which have been determined using simultaneous Reverse Monte Carlo fitting of neutron and X-ray total-scattering data, potassium EXAFS, and diffuse-scattering patterns in electron diffraction. Within the A-sites, Na cations are found to be strongly off-centered along the polar axis as a result of oversized cube-octahedral cages determined by the larger K ions. These Na displacements promote off-centering of the neighboring Nb ions, so that the Curie temperature and spontaneous polarization remain largely unchanged with increasing x, despite the shrinking octahedral volumes. The enhancement of the properties near x = 0.5 is attributed to an abrupt increase in the magnitude and probability of the short-range ordered octahedral rotations, which resembles the pre-transition behavior. These rotations reduce the bond tension around Na and effectively soften the short Na-O bond along the polar axis - an effect that is proposed to facilitate reorientation of the polarization as external electric field is applied.

Elucidating the medium-resolution structure of ribosomal particles: an interplay between electron cryo-microscopy and X-ray crystallograhy.

BACKGROUND: Ribosomes are the universal cellular organelles that accomplish the translation of the genetic code into proteins. Electron cryo-microscopy (cryo-EM) has yielded fairly detailed three-dimensional reconstructions of ribosomes. These were used to assist in the determination of higher resolution structures by X-ray crystallography. RESULTS: Molecular replacement studies using cryo-EM reconstructions provided feasible packing schemes for crystals of ribosomes and their two subunits from Thermus thermophilus, and of the large subunits from Haloarcula marismortui. For the large subunits, these studies also confirmed the major heavy-atom sites obtained by single isomorphous replacement combined with anomalous diffraction (SIRAS) and by multiple isomorphous replacement combined with anomalous diffraction (MIRAS) at approximately 10 A. Although adequate starting phases could not be obtained for the small subunits, the crystals of which diffract to 3.0 A, cryo-EM reconstructions were indispensable for analyzing their 7.2 A multiple isomorphous replacement (MIR) map. This work indicated that the conformation of the crystallized small subunits resembles that seen within the 70S ribosomes. Subsequently, crystals of particles trapped in their functionally active state were grown. CONCLUSIONS: Single-particle cryo-EM can contribute to the progress of crystallography of non-symmetrical, large and flexible macromolecular assemblies. Besides confirming heavy-atom sites, obtained from flat or overcrowded difference Patterson maps, the cryo-EM reconstructions assisted in elucidating packing arrangements. They also provided tools for the identification of the conformation within the crystals and for the estimation of the level of inherent non-isomorphism.

Scoping review of instruments measuring attitudes toward disability.

BACKGROUND: Negative attitudes toward disability cause difficulties in integrating persons with disabilities (PWDs) into society and limit their access to health care, education, employment, and leisure. Being aware of societal attitudes toward disability may help explain discrimination against PWDs and draw attention to the solutions needed to address these. Good measures of attitudes are vital for this purpose. OBJECTIVE: The aim is to synthesize published information, including evidences on psychometric properties and overall utility on instruments that measure attitudes toward disability. METHODS: A two-tiered search process was performed to identify instruments that measure attitudes toward disability and retrieve articles that describe their development and/or validation. The CanChild Outcome Measures Rating Form was utilized to determine the overall utility of the instruments. Results were synthesized using a self-constructed data extraction form. RESULTS: Thirty-one instruments were included in the study. Five measured attitudes toward communication disability, 7 toward intellectual disability, 4 toward mental illness, and 15 toward disability in general. Target respondents ranged from children to adults, and included respondents from different occupations and cultural backgrounds. Twenty-three were found to have adequate overall utility, while 8 have poor overall utility. CONCLUSION: Several instruments are available in literature and all may be used for their intended purposes as long as their limitations are considered. Many still require further validation to ascertain their validity and responsiveness to change.

Comment on the carbon-hydrogen stretching region of vibrational Raman spectra of phospholipids.

The broad, environmentally sensitive 2935-2910 cm-1 feature in the vibrational Raman spectra of phospholipids originates primarily from methylene symmetric carbon-hydrogen (C-H) stretching modes. For ordered acyl chains exhibiting local C2h symmetry at low temperatures, the infrared active methylene C-H asymmetric stretching modes become increasingly apparent at higher temperatures in the Raman spectrum as intramolecular chain disorder (trans-gauche isomerization) leads to a loss of chain symmetry. The 2935 cm-1 shoulder, assigned to the acyl chain methyl group C-H symmetric stretching vibration, is difficult to distinguish as a separate spectral transition in the chain disordered state. An ordering of lipid fluidity for several phospholipids is presented in terms of the intensities of features in the 3000-2800 cm-1 region with particular emphasis upon the 2935-2910 cm-1 contour.

Vibrational Raman spectra of lipid systems containing amphotericin B.

Resonance-enhanced and normal vibrational Raman spectra were observed for both multilamellar and single-wall vesicle assemblies of dimyristoyl phosphatidylcholine containing amphotericin B, a channel-forming polyene antibiotic, and cholesterol. The decrease in the frequency of the polyene antibiotic C = C stretching mode at 1556 cm-1 and the increase in intensity of the C-C-H in-plane deformation mode at 1002 cm-1 indicate that amphotericin B is ordered in a lipid-cholesterol medium similarly to the solid, but is surrounded by a slightly more polar environment. The intensity of the C = C stretching mode I1556 decreases 4-fold during the broadened gel to liquid crystalline phase transition (16--32 degrees C) of dimyristoyl lecithin-cholesterol (4 : 1) multilayers. Other resonance-enhanced vibrations of amphotericin B exhibit similar behavior. For amphotericin B in pure dimyristoyl lecithin multilayer or vesicle systems, however, the vibrational intensity associated with the C = C stretching mode remains constant during the melting of lipid hydrocarbon chains. In addition, a third effect occurs in liquid crystalline egg lecithin-cholesterol (4 : 1, mol ratio) multilayers in which I 1556 first increases by 25% between 3 and 25 degrees C, in parallel with the loss of active channels, and then remains constant as the temperature increases from 25 to 42 degrees C. This latter intensity pattern is masked in the dimyristoyl lecithin-cholesterol system by the overwhelming effect upon the C = C mode from changes in the lipid chain packing characteristics which occur during the phase transition. The broadened phase transition in 4 : 1 dimyristoyl lecithin-cholesterol multilayers (16--32 degrees C), as followed by the ratio of intensities at 2880 and 2850 cm-1 (asymmetric and symmetric methylene C-H stretching modes, respectively) is slightly narrowed by the addition of amphotericin B, and effect from which a binding stoichiometry at 24 degrees of 1 : 1 amphotericin B: cholesterol is estimated. This stoichiometry was confirmed by differential calorimetric scans, which also show the presence of a peak proportional to cholesterol content. Raman I2880/2850 peak height ratios in pure dimyristoyl lecithin bilayers were increased over the 14--38 degrees C range by amphotericin B, a spectral effect which suggests an ordering of the lipid matrix perhaps as a consequence of the polyene binding to the bilayer surface. For bilayers containing cholesterol, the ratios of intensities of the 2935 cm-1 feature, composed mainly of acyl chain terminal methyl and underlying methylene C-H stretching modes, to the 2850 cm-1 feature are significantly increased by amphotericin B. This effect indicates that the antibiotic penetrates the bilayer in the lipid-sterol system.

Evidence for acyl chain trans/gauche isomerization during the thermal pretransition of dipalmitoyl phosphatidylcholine bilayer dispersions.

In order to clarify, in dipalmitoyl phosphatidylcholine multilayers, the effect of the 34 degrees C thermal pretransition on the acyl chain intramolecular disordering process, Raman spectra of dipalmitoyl phosphatidylcholine gels at 20 and 34 degrees C were compared in the 1000--1200 cm-1 skeletal C-C stretching region. In addition to an overall intensity decrease associated with a change in chain packing characteristics, the growth of intensity in the 1080--1090 and 1122 cm-1 regions in the 34--20 degrees C) difference spectrum clearly indicates that the thermal pretransition is accompanied by an increase in the population of hydrocarbon chain gauche rotamers toward the center of the bilayer.