Low-temperature nanoscale heat transport in a gadolinium iron garnet heterostructure probed by ultrafast x-ray diffraction.

Time-resolved x-ray diffraction has been used to measure the low-temperature thermal transport properties of a Pt/Gd3Fe5O12//Gd3Ga5O12 metal/oxide heterostructure relevant to applications in spin caloritronics. A pulsed femtosecond optical signal produces a rapid temperature rise in the Pt layer, followed by heat transport into the Gd3Fe5O12 (GdIG) thin film and the Gd3Ga5O12 (GGG) substrate. The time dependence of x-ray diffraction from the GdIG layer was tracked using an accelerator-based femtosecond x-ray source. The ultrafast diffraction measurements probed the intensity of the GdIG (1 -1 2) x-ray reflection in a grazing-incidence x-ray diffraction geometry. The comparison of the variation of the diffracted x-ray intensity with a model including heat transport and the temperature dependence of the GdIG lattice parameter allows the thermal conductance of the Pt/GdIG and GdIG//GGG interfaces to be determined. Complementary synchrotron x-ray diffraction studies of the low-temperature thermal expansion properties of the GdIG layer provide a precise calibration of the temperature dependence of the GdIG lattice parameter. The interfacial thermal conductance of the Pt/GdIG and GdIG//GGG interfaces determined from the time-resolved diffraction study is of the same order of magnitude as previous reports for metal/oxide and epitaxial dielectric interfaces. The thermal parameters of the Pt/GdIG//GGG heterostructure will aid in the design and implementation of thermal transport devices and nanostructures.

The experiences of adult nursing students completing a placement during the COVID-19 pandemic.

BACKGROUND: The emergency measures implemented by the Nursing and Midwifery Council in response to the COVID-19 pandemic provided nursing students in their final 6 months of study with the opportunity to complete a paid consolidation clinical placement and thus increase their personal responsibility for the care they delivered under supervision. AIM: To explore the experiences of third-year nursing students who completed their final clinical placement during the COVID-19 pandemic. METHODS: Semi-structured interviews were conducted via a virtual platform. FINDINGS: Three themes were identified: the importance of support mechanisms, the development of confidence, and innovative learning opportunities. Students reported improved confidence in the transition period to registered practitioner and felt well supported, which enabled them to take greater responsibility. CONCLUSION: This study provided insight into the experience of nursing students during the COVID-19 pandemic, and found that support mechanisms, and a sense of belonging, helped to increase their confidence in clinical practice.

A Simple Zinc-Mediated Method for Selenium Addition to Michael Acceptors.

In this work, we focused our attention on seleno-Michael type reactions. These were performed using zinc-selenolates generated in situ from diphenyl diselenide 1, 1,2-bis(3-phenylpropyl)diselenide 30, and protected selenocystine 31 via an efficient biphasic Zn/HCl-based reducing system. Alkenes with a variety of electron-withdrawing groups were investigated in order to gauge the scope and limitations of the process. Results demonstrated that the addition to acyclic α,ß-unsaturated ketones, aldehydes, esters amides, and acids was effectively achieved and that alkyl substituents at the reactive ß-centre can be accommodated. Similarly, cyclic enones undergo efficient Se-addition and the corresponding adducts were isolated in moderate to good yield. Vinyl sulfones, α,ß-unsaturated nitriles, and chalcones are not compatible with these reaction conditions. A recycling experiment demonstrated that the unreacted Zn/HCl reducing system can be effectively reused for seven reaction cycles (91% conversion yield at the 7° recycling rounds).

Dietary Docosahexaenoic Acid Reduces Oscillatory Wall Shear Stress, Atherosclerosis, and Hypertension, Most Likely Mediated via an IL-1-Mediated Mechanism.

BACKGROUND: Hypertension is a complex condition and a common cardiovascular risk factor. Dietary docosahexaenoic acid (DHA) modulates atherosclerosis and hypertension, possibly via an inflammatory mechanism. IL-1 (interleukin 1) has an established role in atherosclerosis and inflammation, although whether IL-1 inhibition modulates blood pressure is unclear. METHODS AND RESULTS: Male apoE-/- (apolipoprotein E-null) mice were fed either a high fat diet or a high fat diet plus DHA (300 mg/kg per day) for 12 weeks. Blood pressure and cardiac function were assessed, and effects of DHA on wall shear stress and atherosclerosis were determined. DHA supplementation improved left ventricular function, reduced wall shear stress and oscillatory shear at ostia in the descending aorta, and significantly lowered blood pressure compared with controls (119.5±7 versus 159.7±3 mm Hg, P<0.001, n=4 per group). Analysis of atheroma following DHA feeding in mice demonstrated a 4-fold reduction in lesion burden in distal aortas and in brachiocephalic arteries (P<0.001, n=12 per group). In addition, DHA treatment selectively decreased plaque endothelial IL-1ß (P<0.01). CONCLUSIONS: Our findings revealed that raised blood pressure can be reduced by inhibiting IL-1 indirectly by administration of DHA in the diet through a mechanism that involves a reduction in wall shear stress and local expression of the proinflammatory cytokine IL-1ß.

Concurrent Use of Herbal and Orthodox Medicines among Residents of Tamale, Northern Ghana, Who Patronize Hospitals and Herbal Clinics.

Despite the development of more researched and formulated orthodox medicines, herbal medicines continue to be well patronized for persons across the world with some patrons concurrently using both forms, oblivious of the unwanted effects that may occur. Using a multistage sampling procedure, a semistructured questionnaire was used to collect data in April 2016 from 240 informants from three selected hospitals and three herbal clinics in Tamale, a city in northern Ghana. Using Statistical Package for the Social Sciences, binary logistic regression was used to determine sociodemographic predictors of concurrent use of herbal and orthodox medicines. Orthodox medicines were the drug of choice for 54.2% and 49.2% of patrons of hospitals and herbal clinics, respectively. Also, 67.5% of herbal clinic patrons used orthodox medicines, while 25.0% of hospital attendees used herbal medications prior to their visit to the health facilities. Up to 17.9% of respondents concurrently used herbal and orthodox medicines for their prevailing ailment with age, less than 30 years being the only predictor of this habit (p = 0.015; 95% CI, 1.183-4.793; cOR = 2.4). All health professionals including those in herbal clinics should therefore be interested in the drug history of their clients.

Medical students' knowledge and attitude towards complementary and alternative medicine - A survey in Ghana.

Interest, use of and research into Complementary and Alternative Medicine (CAM; bǔ chong yǔ tì dài yi xué) is on the increase in recent times even in developed countries. It may therefore be appropriate if medical students who would become future physicians possess adequate knowledge and better attitude towards CAMS. This study assessed medical students' knowledge of, attitude towards, and usage of CAM as well as their opinion about integrating CAMs into the medical curriculum. In a cross-sectional study, 203 medical students in 2nd, 3rd and 4th year classes completed a questionnaire. Data was analyzed using SPSS 18 and GraphPad 5.01. Association between different variables was tested. The overall mean knowledge score was 19.6%. Students in higher years of study were significantly more knowledgeable in CAMs (p = 0.0006). The best known CAM was herbal medicine (63.6%), with relatives and friends being their main source of information. Students' attitude towards CAM was good (75.1%) with majority (71.5%) favouring introduction of CAM into the medical curriculum; preferably at the preclinical level (67.5%). Year of study, gender and locality where student grew up did not significantly affect attitude towards CAM use. Up to 117 (59.0%) of the students had ever used CAM especially herbal medicine. Although students in this study were deficient in knowledge on CAMs, their attitude and usage was good. Herbal medicine was the best known and used CAM. Majority of the students believed knowledge on CAM would be beneficial to their practice hence, desirous of its introduction into their medical curriculum.

Regulator of G Protein Signaling 14: A Molecular Brake on Synaptic Plasticity Linked to Learning and Memory.

The regulators of G protein signaling (RGS) proteins are a diverse family of proteins that function as central components of G protein and other signaling pathways. In the brain, regulator of G protein signaling 14 (RGS14) is enriched in neurons in the hippocampus where the mRNA and protein are highly expressed. This brain region plays a major role in processing learning and forming new memories. RGS14 is an unusual RGS protein that acts as a multifunctional scaffolding protein to integrate signaling events and pathways essential for synaptic plasticity, including conventional and unconventional G protein signaling, mitogen-activated protein kinase, and, possibly, calcium signaling pathways. Within the hippocampus of primates and rodents, RGS14 is predominantly found in the enigmatic CA2 subfield. Principal neurons within the CA2 subfield differ from neighboring hippocampal regions in that they lack a capacity for long-term potentiation (LTP) of synaptic transmission, which is widely viewed as the cellular substrate of learning and memory formation. RGS14 was recently identified as a natural suppressor of LTP in hippocampal CA2 neurons as well as forms of learning and memory that depend on the hippocampus. Although CA2 has only recently been studied, compelling recent evidence implicates area CA2 as a critical component of hippocampus circuitry with functional roles in mediating certain types of learning and memory. This review will highlight the known functions of RGS14 in cell signaling and hippocampus physiology, and discuss potential roles for RGS14 in human cognition and disease.

Absolute configuration of falcarinol (9Z-heptadeca-1,9-diene-4,6-diyn-3-ol) from Pastinaca sativa.

Falcarinol (9Z-heptadeca-1,9-diene-4,6-diyn-3-ol; (1) is a polyacetylene commonly found in several plant families. The absolute configuration of naturally occurring 1 is not clear and contradictory results have been reported in the literature. Determination of the absolute configuration of 1 from Pastinaca sativa L. was carried out. Isolation of 95% pure 1 was performed via successive fractionation and preparative-HPLC. A racemic mixture comprised of 3R-1 and 3S-1 was synthesized in order to confirm the absolute configuration of the isolated natural product using chiral HPLC. Based on a combination of chiral HPLC and specific rotation, 1 present in P. saliva was found to have a 3R absolute configuration (i.e. (3R, 9Z)-heptadeca-1,9-diene-4,6-diyn-3-ol).

Mitoxantrone in combination with an inhibitor of DNA-dependent protein kinase: a potential therapy for high risk B-cell chronic lymphocytic leukaemia.

Defects in the DNA damage response pathway [e.g. del(17p)] are associated with drug-resistant B-cell chronic lymphocytic leukaemia (CLL). We previously demonstrated that over-expression of DNA-dependent protein kinase (DNA-PK) correlates with chemo-resistance and that inhibition of DNA-PK sensitizes CLL cells to chemotherapeutics. Here, we investigated expression of DNA-PK and other proteins that impact on drug resistance, and evaluated the effects of a DNA-PK inhibitor (NU7441) on mitoxantrone-induced cytotoxicity in CLL cells. NU7441 sensitized cells from 42/49 CLL samples to mitoxantrone, with sensitization ranging from 2- to 200-fold Co-culture of CLL cells in conditioned stromal medium increased chemoresistance but did not reduce sensitization by NU7441. Mitoxantrone treatment induced γH2AX foci and NU7441 increased their longevity (24 h). NU7441 prevented mitoxantrone-induced autophosphorylation of the DNA-PK catalytic subunit (DNA-PKcs) at Ser 2056, confirming that DNA-PK participates in repair of mitoxantrone-induced DNA damage. del(17p) cases were more resistant to mitoxantrone than del(13q) cases, but were resensitized (7-16 fold) by co-incubation with NU7441. Expression of DNA-PKcs, Ku80, P-glycoprotein and topoisomerase IIß were significantly higher in del(17p) cases. PRKDC mRNA levels correlated with DNA-PKcs protein expression, which predicted shorter survival. These data confirm the potential of DNA-PK as a therapeutic target in poor prognosis CLL.

Celecoxib activates PI-3K/Akt and mitochondrial redox signaling to enhance heme oxygenase-1-mediated anti-inflammatory activity in vascular endothelium.

Although nonsteroidal anti-inflammatory drugs (NSAIDs) provide important control of pain and inflammation, they have been overshadowed by concerns regarding atherothrombotic complications. However, celecoxib seems to have a relatively good cardiovascular profile and may improve endothelial function in coronary heart disease. This led us to the hypothesis that celecoxib induces the vasculoprotective enzyme heme oxygenase-1 (HO-1). In human umbilical vein and aortic endothelial cells, 24-48 h treatment with celecoxib induced HO-1 mRNA and protein expression and increased HO-1 enzyme activity. This effect was not seen with rofecoxib or indomethacin. Supplementation of culture medium with iloprost or prostaglandin E(2) failed to reverse celecoxib-mediated HO-1 induction, indicating a cyclooxygenase-independent mechanism. Rather, this action of celecoxib involved generation of mitochondria-derived reactive oxygen species, Akt phosphorylation, and nuclear translocation of the transcription factor Nrf2, with N-acetylcysteine, PI-3K antagonist LY290042, and dominant-negative Akt abrogating the effects. Furthermore, celecoxib-induced HO-1 was inhibited by dominant-negative Nrf2. The functional significance of HO-1 induction was revealed by celecoxib-mediated inhibition of VCAM-1 expression, a response reversed by the HO-1 antagonist zinc protoporphyrin. HO-1 induction provides a molecular mechanism for clinical observations indicating relative freedom from atherothrombotic complications in patients taking celecoxib compared to other NSAIDs with comparable anti-inflammatory activity.

Does the medical college admission test predict global academic performance in osteopathic medical school?

OBJECTIVE: To investigate the extent to which Medical College Admission Test (MCAT) subscores predict the overall academic performance of osteopathic medical students. METHODS: We examined the value of MCAT subscores in predicting students' global academic performance in osteopathic medical school, as defined by grade point average in basic science (basic GPA), clinical instruction (clinical GPA), cumulative grade point average (total GPA), and national licensing examination scores on the Comprehensive Osteopathic Medical Licensing Examination-USA (COMLEX-USA) Level 1 and Level 2. Subjects were 434 osteopathic medical students of the Oklahoma State University College of Osteopathic Medicine in Tulsa who either graduated or were expected to graduate between the years 1999 and 2003. Standard, multivariate linear regression analyses were conducted for each of the five performance variables to assess the relative importance of MCAT subtest scores and cumulative undergraduate GPA (total UGPA) in predicting academic performance. RESULTS: Total UGPA was the most important, significant predictor (beta=.13-.33) in overall student academic performance for all five analyzed variables. Less predictive of overall academic performance (beta=-.01-.21) were MCAT subcores. However, the MCAT biological sciences subscore was a significant predictor of basic GPA (beta=.14), the MCAT physical sciences subscore significantly predicted COMLEX-USA Level 1 scores (beta=.15), and the MCAT verbal reasoning subscore significantly predicted COMLEX-USA Level 2 scores (beta=.21). The subscore for the MCAT writing sample was not a significant predictor of overall academic performance. CONCLUSION: Total undergraduate GPA had the highest predictive value for academic performance as measured by basic GPA, clinical GPA, total GPA, and COMLEX-USA Level 1 and Level 2 scores. The present study found MCAT subscores to be of limited predictive value in determining global academic performance.

Relations between academic performance by medical students and COMLEX-USA Level 2: a multisite analysis.

The Comprehensive Osteopathic Medical Licensing Examination-USA (COMLEX-USA) is a national medical licensing examination for physicians earning the doctor of osteopathic medicine (DO) degree. Little has been published regarding the validity of this relatively new, high-stakes examination. The purpose of this study was to examine the validity of COMLEX-USA Level 2, which is given to fourth-year osteopathic medical students and focuses on clinically relevant content. Nineteen osteopathic medical schools were asked to submit Level 2 scores and associated academic information, including predictions by deans or deans' representatives regarding whether each student would pass the examination. Twelve of the 17 schools that had students eligible to take the Level 2 examination provided data for 1254 (80%) of 1577 first-time test takers in March 2000. The overall mean score of study participants was 533.35, with a pass rate of 91.98%. The highest average correlation with COMLEX-USA Level 2 performance was with COMLEX-USA Level 1 scores (r = 0.76), followed by basic science grade point average (GPA) (r = .66), total GPA as a fourth-year student (r = .65), and clinical GPA (r = .36). Students identified as being at highest risk received the lowest mean score (427.54) and were most likely to fail Level 2. COMLEX-USA Level 2 scores are moderately to highly related to academic achievement in osteopathic medical schools.

Relationship between academic achievement and student performance on the Comprehensive Osteopathic Medical Licensing Examination-USA level 2.

The Comprehensive Osteopathic Medical Licensing Examination-USA (COMLEX-USA) is a three-part examination used for licensing osteopathic physicians. The relationship between performance on this examination and prior student academic performance has been unclear. This study explores the relationship between COMLEX-USA level 2 scores and student academic performance at Oklahoma State University College of Osteopathic Medicine (OSU-COM). All first-time examination candidates from OSU-COM had a formal, weeklong board review in March 2000, and all passed the examination. Predictions about COMLEX-USA scores generated by the academic dean's office at OSU-COM underestimated student examination performance; results suggest a significant correlation between level 2 performance with (1) level 1 performance (.751); (2) grade point average (GPA) in basic science (.659); (3) total GPA (.672); and (4) Medical College Admission Test (MCAT) scores (.406). The correlation of level 2 scores to clinical GPA (.269) was lower but still significant. Results of this study suggest that performance on COMLEX-USA level 2 is strongly correlated with prior student academic performance in this population.