Synchrotron X-ray diffraction investigation of the surface condition of artefacts from King Henry VIII's warship the Mary Rose.

Synchrotron X-ray diffraction (XRD) measured on the XMaS beamline at the ESRF was used to characterize the alloy composition and crystalline surface corrosion of three copper alloy Tudor artefacts recovered from the undersea wreck of King Henry VIII's warship the Mary Rose. The XRD method adopted has a dynamic range ∼1:105 and allows reflections <0.002% of the height of major reflections in the pattern to be discerned above the background without smoothing. Laboratory XRD, scanning electron microscopy-energy dispersive spectroscopy, synchrotron X-ray fluorescence and X-ray excited optical luminescence-X-ray near-edge absorption structure were used as supporting techniques, and the combination revealed structural and compositional features of importance to both archaeology and conservation. The artefacts were brass links believed to be fragments of chainmail and were excavated from the seabed during 1981 and 1982. Their condition reflects very different treatment just after recovery, viz. complete cleaning and conservation, chemical corrosion inhibition and chloride removal only, and distilled water soaking only (to remove the chlorides). The brass composition has been determined for all three at least in the top 7 µm or so as Cu(73%)Zn(27%) from the lattice constant. Measurement of the peak widths showed significant differences in the crystallite size and microstrain between the three samples. All of the links are found to be almost chloride-free with the main corrosion products being spertiniite, sphalerite, zincite, covellite and chalcocite. The balance of corrosion products between the links reflects the conservation treatment applied to one and points to different corrosion environments for the other two.

Self-Efficacy: Changing the Tide of Evidence-Based Practice.

AIMS: The specific aim for this study was to describe differences in evidence-based practice (EBP) and self-efficacy in frontline RNs. This project utilized a national study with a convenience selection of acute care agencies to examine the relationship between organizational and unit culture, EBP, and self-efficacy in frontline nurses. METHODS: This national study used descriptive correlational methodology to describe differences in EBP and self-efficacy among RNs. The sample included 245 frontline RNs employed in acute care settings. To measure the study variables, the Nursing Evidence-Based Practice Survey (Titler, Hill, Matthews, & Reed, 1999)  and the Evidence-Based Nursing Practice Self-Efficacy Scale were used (Tucker, Olson, & Frusti, 2009). Each instrument was delivered via the Qualtrics online platform. RESULTS: The correlation of bivariate interval level variables was analyzed using Pearson's r. The correlation between EBP and self-efficacy was strongly correlated: r(170) = .537, p = .01. Sections within the Nursing Evidence-Based Practice Survey were calculated and found to be significant (unit culture r = .241, p = .01; organizational culture r = .570, p = .01; knowledge, skills, attitude r = .538, p = .01). LINKING EVIDENCE TO ACTION: Several implications exist for education, staff development, and nursing management. Nursing school programs incorporate EBP into the curriculum so that nurses have a foundation for EBP. However, staff development professionals in clinical settings must continue to build on the nurses' knowledge and skill, thus increasing self-confidence for EBP. Nursing management can provide the resources for staffing models and policies to reinforce the value of EBP and positive patient outcomes. This combination provides frontline staff with EBP participation and increased self-efficacy in its usage.

The PROTACtable genome.

Proteolysis-targeting chimeras (PROTACs) are an emerging drug modality that may offer new opportunities to circumvent some of the limitations associated with traditional small-molecule therapeutics. By analogy with the concept of the 'druggable genome', the question arises as to which potential drug targets might PROTAC-mediated protein degradation be most applicable. Here, we present a systematic approach to the assessment of the PROTAC tractability (PROTACtability) of protein targets using a series of criteria based on data and information from a diverse range of relevant publicly available resources. Our approach could support decision-making on whether or not a particular target may be amenable to modulation using a PROTAC. Using our approach, we identified 1,067 proteins of the human proteome that have not yet been described in the literature as PROTAC targets that offer potential opportunities for future PROTAC-based efforts.

Monoclinic distortion, polarization rotation and piezoelectricity in the ferroelectric Na0.5Bi0.5TiO3.

The relationship between crystal structure and physical properties in the ferroelectric Na0.5Bi0.5TiO3 (NBT) has been of interest for the last two decades. Originally, the average structure was held to be of rhombohedral (R3c) symmetry with a fixed polarization direction. This has undergone a series of revisions, however, based on high-resolution X-ray diffraction, total neutron scattering, and optical and electron microscopy. The recent experimental findings suggest that the true average symmetry is monoclinic (space group Cc), which allows for a rotatable spontaneous polarization. Neither polarization rotation nor its potentially important real role in enhanced piezoelectricity is well understood. The present work describes an in situ investigation of the average monoclinic distortion in NBT by time-resolved single-crystal X-ray diffraction under external electric fields. The study presents a high-resolution inspection of the characteristic diffraction features of the monoclinic distortion - splitting of specific Bragg reflections - and their changes under a cyclic electric field. The results favour a model in which there is direct coupling between the shear monoclinic strain and the polarization rotation. This suggests that the angle of polarization rotation under a sub-coercive electric field could be 30° or more.

Unexpectedly high piezoelectricity of Sm-doped lead zirconate titanate in the Curie point region.

Large piezoelectric coefficients in polycrystalline lead zirconate titanate (PZT) are traditionally achieved through compositional design using a combination of chemical substitution with a donor dopant and adjustment of the zirconium to titanium compositional ratio to meet the morphotropic phase boundary (MPB). In this work, a different route to large piezoelectricity is demonstrated. Results reveal unexpectedly high piezoelectric coefficients at elevated temperatures and compositions far from the MPB. At temperatures near the Curie point, doping with 2 at% Sm results in exceptionally large piezoelectric coefficients of up to 915 pm/V. This value is approximately twice those of other donor dopants (e.g., 477 pm/V for Nb and 435 pm/V for La). Structural changes during the phase transitions of Sm-doped PZT show a pseudo-cubic phase forming ≈50 °C below the Curie temperature. Possible origins of these effects are discussed and the high piezoelectricity is posited to be due to extrinsic effects. The enhancement of the mechanism at elevated temperatures is attributed to the coexistence of tetragonal and pseudo-cubic phases, which enables strain accommodation during electromechanical deformation and interphase boundary motion. This work provides insight into possible routes for designing high performance piezoelectrics which are alternatives to traditional methods relying on MPB compositions.

Nursing student stories on learning how to think like a nurse.

The ability to think critically, improve clinical systems, and decrease errors in clinical judgments are ever the vision of nursing practice. The author describes the thinking processes of nursing students as they make clinical judgments and the most important teaching/learning strategies that help develop their clinical judgment.

Topology and temperature dependence of the diffuse X-ray scattering in Na0.5Bi0.5TiO3 ferroelectric single crystals.

The results of high-resolution measurements of the diffuse X-ray scattering produced by a perovskite-based Na0.5Bi0.5TiO3 ferroelectric single crystal between 40 and 620 K are reported. The study was designed as an attempt to resolve numerous controversies regarding the average structure of Na0.5Bi0.5TiO3, such as the mechanism of the phase transitions between the tetragonal, P4bm, and rhombohedral | monoclinic, R3c | Cc, space groups and the correlation between structural changes and macroscopic physical properties. The starting point was to search for any transformations of structural disorder in the temperature range of thermal depoling (420-480 K), where the average structure is known to remain unchanged. The intensity distribution around the {032} pseudocubic reflection was collected using a PILATUS 100K detector at the I16 beamline of the Diamond Light Source (UK). The data revealed previously unknown features of the diffuse scattering, including a system of dual asymmetric L-shaped diffuse scattering streaks. The topology, temperature dependence, and relationship between Bragg and diffuse intensities suggest the presence of complex microstructure in the low-temperature R3c | Cc phase. This microstructure may be formed by the persistence of the higher-temperature P4bm phase, built into a lower-temperature R3c | Cc matrix, accompanied by the related long-range strain fields. Finally, it is shown that a correlation between the temperature dependence of the X-ray scattering features and the temperature regime of thermal depoling is present.

An investigation of Zr doping in NaBiTi2O6 perovskite by direct hydrothermal synthesis.

The direct crystallisation of perovskites NaBi(Ti(1-x)Zrx)(2)O(6) with x = 0, 0.01, 0.05 and 0.1 at 240 °C is achieved from aqueous alkali (NaOH) solutions of NaBiO(3), TiF(3) and ZrOCl(2). For each material, a single rhombohedral polymorph (R3c a∼ 5.51 Å, c∼ 13.50 Å) can be fitted to powder X-ray diffraction data, with Rietveld refinement showing a linear increase in lattice parameters and unit cell volume with increasing Zr content. Scanning electron microscopy shows micron-sized cube-shaped crystallites for each sample, with energy-dispersive X-ray analysis giving Bi : Ti : Zr ratios consistent with the expected substitution. Raman spectroscopy shows no perturbance of local structure upon Zr doping and the spectrum shows five broad bands, consistent with the literature on similar materials. Attempts to increase the Zr content further (x > 0.1) were unsuccessful by this hydrothermal synthesis method, leading instead to crystalline ZrO(2) by-products. For NaBiTi(2)O(6) and NaBi(Ti(0.99)Zr(0.01))(2)O(6) densified ceramics were prepared (∼95% density of crystallographic value) and their remnant polarisation was found to be reduced upon Zr substitution, along with a higher maximum piezoelectric coefficient, d33, measured and comparable permittivity and dielectric loss to other reported NaBiTi(2)O(6) materials.

Assessment of copper corrosion from frameless copper IUDs after long-term in utero residence.

OBJECTIVE: To assess the site-specific corrosive behavior of the frameless intrauterine device (IUD) following long-term exposure to the uterine environment. STUDY DESIGN: A qualitative and morphological study using X-ray diffraction (XRD) and scanning electron microscopy (SEM). RESULTS: Three GyneFix® IUDs that were in site up to 150 months were examined. In utero corroded copper sleeves were divided into 10 different groups based on their shape (U or O), orientation (inside or outside) and in utero residence time. XRD indicated the presence of solely cuprite (Cu2O) as corrosion product on both the inside and the outside of the copper sleeves, regardless of their shape. These results were confirmed by backscattered electron micrographs recorded on the inside, the outside and the cross-section of the IUD sleeve. SEM results suggest that shape and orientation slightly affect the corrosion rate. CONCLUSION: The apparent copper loss from both sides of GyneFix copper tubes proves that both sides are a potential copper source and therefore justifies the design of GyneFix IUD. This could be beneficial for women as the IUD could be reduced in size and therefore better tolerated. The impact on bleeding could also be minimized. IMPLICATION STATEMENT: Release of copper ions from both sides of the copper tubes of the frameless GyneFix® IUD allows the IUD to be reduced in size, contributing to better toleration. The impact on menstrual bleeding is also minimized by a smaller size of the foreign body.

Extrauterine growth restriction remains a serious problem in prematurely born neonates.

BACKGROUND: Poor growth is a common problem in premature neonates and may be associated with neurodevelopmental delay. OBJECTIVE: To evaluate the incidence of extrauterine growth restriction (growth values < or =10th percentile of intrauterine growth expectation based on estimated postmenstrual age in premature (23-34 weeks' estimated gestational age) neonates at the time they are discharged from the hospital. DESIGN/METHODS: Using a database formed from a computer-assisted tool that generates clinical progress notes and discharge summaries on neonatal intensive care unit admissions, we reviewed data on neonates discharged from 124 neonatal intensive care units between January 1, 1997, and December 31, 2000. We evaluated neonates who were born between 23 and 34 weeks' estimated gestational age without congenital anomalies and who were cared for at and discharged from the same hospital. For each patient, we compared the discharge growth values to the expected values based on our intrauterine growth data and postmenstrual age on the day of discharge. We defined extrauterine growth restriction as having a measured growth value (weight, length or head circumference) that was < or =10th percentile of the predicted value. In each specific birth weight and estimated gestational age group, we counted the number of neonates < or =10th percentile for each growth parameter and calculated the percentage of patients who had values < or =10th percentile at discharge. Using logistic regression, we evaluated the factors associated with extrauterine growth restriction for weight, length, and head circumference. RESULTS: Our sample included 24 371 premature neonates. Data on discharge weight, length, and head circumference was available on 23 970, 17 203, and 20 885 neonates, respectively. The incidence of extrauterine growth restriction was common (28%, 34%, and 16% for weight, length, and head circumference, respectively). For each growth parameter, the incidence of extrauterine growth restriction increased with decreasing estimated gestational age and birth weight. Factors independently associated with extrauterine growth restriction were male gender, need for assisted ventilation on day 1 of life, a history of necrotizing enterocolitis, need for respiratory support at 28 days of age, and exposure to steroids during the hospital course. CONCLUSIONS: Extrauterine growth restriction remains a serious problem in premature neonates especially for neonates who are small, immature, and critically ill.

Enteral glutamine supplementation and morbidity in low birth weight infants.

OBJECTIVE: To determine if glutamine-supplemented enteral nutrition decreased the incidence of nosocomial sepsis in neonates. METHODS: In a multicenter (n = 20) clinical trial, we randomly allocated infants (n = 649) with birth weight between 500 and 1250 g, who were <7 days of age, and had no major anomalies to receive enteral glutamine supplementation (0.3 g/kg/day) or sterile water (placebo) for the first 28 days. The primary outcome variable was the number of infants who had blood culture-proven nosocomial sepsis between 7 days' and 36 weeks' postmenstrual age. RESULTS: Infants were assigned to placebo (n = 335) or to glutamine supplementation (n = 314). Neonates assigned to glutamine were similar to those assigned placebo for demographic characteristics and nutritional support during the first week. There was no difference in the occurrence of culture-proven nosocomial sepsis (33.7% vs 30.9%) or suspected sepsis (51.6% vs 47.1%) between the placebo and glutamine groups; however, neonates treated with glutamine less often had gastrointestinal dysfunction (7.5% vs 2.5%, P <.01) and severe neurologic sequelae (15.1% vs 10.4%, P =.08). CONCLUSIONS: At a dose of 0.3 g/kg/day, enteral glutamine does not appear to reduce nosocomial sepsis in premature neonates.

Comparison of the proteome of Mycobacterium tuberculosis strain H37Rv with clinical isolate CDC 1551.

The genome sequences of two virulent strains of Mycobacterium tuberculosis (H37Rv and CDC 1551) are now available. CDC 1551 is a recent clinical isolate and H37Rv is a commonly used lab strain which has been subject to in vitro passage. The two strains have been shown to display differing phenotypes both in vivo and in vitro. The proteome of the two strains grown in liquid culture were examined over time to determine whether there are any major differences between them at the protein level and the differences were compared to the genome data. Total cell lysates of the two strains were analysed by two-dimensional electrophoresis. Approximately 1750 protein spots were visualized by silver staining and the protein profiles of the two strains were found to be highly similar. Out of a total of 17 protein spot differences, seven were unique to CDC 1551 and three to H37Rv. Two further spots showed increased intensity in H37Rv, one spot showed differing vertical mobility between the strains and four showed differing spot intensities with time. Twelve of the spot differences were identified using mass spectrometry; however, no obvious association with phenotype could be deduced. When genome differences were analysed and related to the proteome differences, a mobility shift identified in the MoxR protein could be explained by a point mutation at the gene level. This proteome analysis reveals that, despite having been maintained under vastly different conditions, namely in vitro passage and in vivo transmission, these two strains have remained highly similar.

Improving growth of very low birth weight infants in the first 28 days.

OBJECTIVE: To increase weight gain in the first 28 days after birth for very low birth weight (VLBW) infants by isolating and sharing meaningful process differences between high- and low-weight-gain centers within a neonatal network. DESIGN/METHODS: We identified weight gain as an important target for improvement in 1999 for our national group practice of neonatologists. Site-specific average weight gain during the first 28 days was the primary outcome measure. Our target population was defined as inborn infants who survived and remained in the hospital of birth, whose birth weights were between 401 and 1500 g (VLBW), and who were >22 weeks' estimated gestational age. A team of 6 neonatologists and 1 nurse met, reviewed processes that might influence growth, and developed a structured observation guide for site visits. Weight gain data were obtained from an existing administrative database for the period January 1, 1997, through June 30, 1999. Centers were ranked and divided into upper, middle, and lower thirds. Seven team members visited 1 high- and 1 low-weight-gain center without being informed of the center's performance. Following the site visits, the team isolated 16 meaningful differences between high- and low-weight-gain sites. Meaningful differences were defined as processes observed in all or virtually all (for this project, 6 or 7 of 7 centers) of the high and none or virtually none (for this project, 0 or 1 of 7) of the low centers. The meaningful differences were distributed to our medical directors in August 2000 along with their site-specific weight-gain performance. To document the impact of sharing this material, we compared weight gain in a baseline period of January 1 through December 31, 1999 and a posteducational intervention period of January 1 through September 30, 2001. RESULTS: Compared with neonates admitted to our national neonatal practice in 1999, neonates admitted in 2001 were similar in birth weight, gestational age at birth, exposure to antenatal steroids, and male gender. Average daily weight gain during the first 28 days increased from 10.4 +/- 6 g for neonates cared for in 1999 to 12.5 +/- 6 g for neonates cared for in 2001. Thirty-nine of 51 (76%) units noted improvements, 4 were unchanged and 8 noted a decrease in average weight gain. Despite similar average lengths of stay, the average discharge weight for neonates sent home increased from 2.15 +/- 0.5 kg for 1999 to 2.29 +/- 0.5 kg for 2001. There were no differences in frequencies of mortality or major morbidities, including severe intraventricular hemorrhage, retinopathy, or necrotizing enterocolitis, between the 2 time periods. An increase in the use of continuous positive airway pressure was noted in the post implementation period. CONCLUSIONS: Variation in common processes can alter clinical outcomes. Although temporal trends in weight gain may be, in part, responsible for this trend, it appears that isolation and implementation of meaningful differences in processes can augment our desire to rapidly improve clinical outcomes.