bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of agonist efficacy using an α2A‐adrenoceptor‐Gi1α fusion protein
Authors: Wise Alan , Carr I.Craig , Groarke D.Alex , Milligan Graeme
Published: July 2002

A fusion protein was constructed between the porcine α2A‐adrenoceptor and a pertussis toxin‐insensitive (Cys351Gly) form of the α subunit of the G protein Gi1. Addition of agonist ligands to membranes of COS‐7 cells transiently transfected to express this construct, and treated with pertussis toxin prior to cell harvest, resulted in stimulation of both high affinity GTPase activity and enhanced binding of [35S]GTPγS. By considering the fusion protein as an agonist‐activated enzyme and measuring V
max of GTP hydrolysis a range of agonist ligands displayed varying efficacy in their capacity to activate the receptor‐associated G protein with adrenaline=noradrenaline=α‐methylnoradrenaline>UK14304>BHT933≥xylazine=clonidine. A similar rank order was observed following independent co‐expression of the α2A‐adrenoceptor and Cys351Gly‐Gi1α. These data demonstrate the utility and applicability of using a receptor‐G protein fusion protein approach, in which the stoichiometry of receptor and G protein is fixed at 1:1, to measure and further understand the nature of agonist efficacy.
Human retinoblastoma protein (Rb) is phosphorylated by cdc2 kinase and MAP kinase in Xenopus maturing oocytes
Authors: Taieb Frédéric , Karaiskou Anthi , Rime Hélène , Jessus Catherine
Published: July 2002

Xenopus oocyte meiotic maturation combines features of G0/G1 and G2/M transitions of the cell cycle. To study the in ovo Rb kinase activity, we have microinjected human Rb into oocytes. Microinjected human Rb localizes into the nucleus, is hypophosphorylated in prophase oocytes, becomes hyperphosphorylated during meiotic maturation and is dephosphorylated as the cell reenters interphase. Inactivation or overexpression of the cyclin D‐cdk4/6 complex in an oocyte extract does not affect the Rb kinase activity. This kinase activity could be attributed to both cdc2‐cyclin B and MAP kinase, opening new perspectives of investigation in somatic cells.
Different effects of an oligonucleotide uptake stimulating protein on leukemic cells in their primitive and differentiated state
Authors: Tóth György , Schlammadinger József , Sipka Sándor , Kiss Attila , Szegedi Gyula , Rák Kálmán , Szabó Gábor
Published: July 2002

The single stranded [3H]oligonucleotide uptake by HL‐60 human promyelocyte and K562 human erythroleukemia cells was stimulated 20–45‐fold by DUSF (DNA uptake stimulating protein), and this effect was drastically reduced (to 1.6–13×) if the cells were induced to differentiate. The oligonucleotide uptake stimulating effect of DUSF was not altered in HL‐60 and K562 cells, if the proliferation of the cells was inhibited by hydroxyurea (HU) treatment. The oligonucleotide uptake by separated granulocytes and mononuclear cells from healthy donors was not stimulated by DUSF, while the uptake of oligonucleotides by myeloid and lymphoid leukemic cells was greatly stimulated (10–15×). The uptake of oligonucleotides by differentiated mononuclear cells of healthy donors could not be stimulated by DUSF, but the oligonucleotide uptake was greatly increased (11×) by DUSF if the cells were subjected to blast transformation.
Conformational analysis of the interdomain linker of the central homology region of chloroplast initiation factor IF3 supports a structural model of two compact domains connected by a flexible tether
Authors: Hua Yuxin , Raleigh Daniel P
Published: July 2002

A peptide corresponding to the interdomain linker of chloroplast IF3 has been synthesized and its structure studied by NMR and CD as a function of temperature and pH. At low temperature and neutral pH the apparent helical content is 25%. pH and ionic strength dependent CD studies demonstrate that sidechain‐sidechain interactions stabilize the structure observed at low temperature. The helicity decreases with temperature and above 25°C the peptide is less than 15% helical. These results indicate that the peptide has little intrinsic tendency to form helical structure at physiologically relevant temperatures and strongly suggests that the linker region is flexible in intact chloroplast IF3.
Uptake of N‐acetyl‐D‐mannosamine: an essential intermediate in polysialic acid biosynthesis by Escherichia coli K92
Authors: Revilla-Nuin Beatriz , Reglero Angel , Ferrero Miguel A , Rodrı́guez-Aparicio Leandro B
Published: July 2002

The N‐acetyl‐D‐mannosamine (ManNAc) transport system of Escherichia coli K92 was studied when this bacterium was grown in a chemically defined medium containing ManNAc as carbon source. Kinetic measurements were carried out in vivo at 37°C in 25 mM phosphate buffer, pH 7.5. Under these conditions, the uptake rate was linear for at least 15 min and the calculated K
m for ManNAc was 280 μM. The transport system was strongly inhibited by sodium arsenate (97%), potassium cyanide (84%) and 2,4‐dinitrophenol (88%) added at final concentrations of 1 mM (each). Analysis of bacterial ManNAc phosphotransferase activity revealed in vitro ManNAc phosphorylation activity only when phosphoenolpyruvate was present. These results strongly support the notion that ManNAc uptake depends on a specific phosphotransferase system. Study of specificities showed that N‐acetylglucosamine and mannosamine specifically inhibited the transport of ManNAc in this bacterium. Analysis of expression revealed that the ManNAc transport system was induced by ManNAc, glucosamine, galactosamine, mannosamine and mannose but not by N‐acetylglucosamine or N‐acetylgalactosamine. Moreover, ManNAc permease was subject to glucose repression and cAMP stimulation. Full induction of the ManNAc transport system required the simultaneous presence of both cAMP and ManNAc.
X‐ray structural analysis of compensating mutations at the barnase‐barstar interface
Authors: Martin Carole , Hartley Robert , Mauguen Yves
Published: July 2002

The crystal structure of the barstar mutants (Y29P) and (Y29D, Y30W) as well as that of the complexes of barstar(Y29P) with wild‐type barnase and barnase(H102K) have been determined. These barstar mutants compensate for the dramatic loss of barnase‐barstar interaction energy caused by a single mutation of the barnase active site His‐102 to a lysine. The latter introduces an uncompensated charge in the pocket at the surface of barstar where Lys‐102 is located. The analysis of the structures suggests a mechanism for this compensation based on the solvation of the charge of Lys‐102. Additional compensation occurs through the formation of a hydrogen bond.
Deletion of a proline‐rich region and a transmembrane domain in fatty acid amide hydrolase1
Authors: Arreaza G. , Deutsch D.G.
Published: July 2002

Fatty acid amide hydrolase contains a proline‐rich sequence matching a consensus sequence for SH3‐binding domains as well as a transmembrane domain. In this study, deletion mutants lacking the proline‐rich region and the transmembrane domain were generated. Transfection experiments demonstrated that the proline‐rich deleted amidase was enzymatically inactive. While immunostaining of the wild‐type was always punctate with strong perinuclear staining characteristic for endoplasmic reticulum, the staining of the mutant was diffuse and distributed throughout the cytoplasm and perinuclear region. These observations along with the loss of activity suggest that the proline‐rich region may play a role in the subcellular localization and enzymatic function. The transmembrane domain‐deleted mutant was indistinguishable from the wild‐type enzyme.
Inhibition of protein tyrosine phosphatases blocks calcium‐induced activation of metaphase II‐arrested oocytes of Xenopus laevis
Authors: Bodart Jean-François , Béchard David , Bertout Marc , Rousseau Arlette , Gannon Julian , Vilain Jean-Pierre , Flament Stéphane
Published: July 2002

We have studied the effect of a protein tyrosine phosphatases (PTP) inhibitor on calcium‐induced activation of Xenopus laevis oocytes arrested at metaphase II. Ammonium molybdate microinjection blocked pronucleus formation following A23187 treatment while cortical granules still underwent exocytosis. Pronuclei still occurred in ammonium molybdate‐injected oocytes following 6‐DMAP addition. Changes that usually occurred following A23187 exposure were inhibited in the presence of ammonium molybdate in the oocyte: MAPK dephosphorylation, p34cdc2 rephosphorylation and cyclin B2 and p39mos proteolysis. These results suggest that a PTP is involved in the activation of the ubiquitin‐dependent degradation machinery.
Functional studies of a glucagon receptor isolated from frog Rana tigrina rugulosa: implications on the molecular evolution of glucagon receptors in vertebrates
Authors: Ngan Elly S.W. , Chow Lillian S.N. , Tse Dicky L.Y. , Du Xixuan , Wei Yang , Mojsov Svetlana , Chow Billy K.C.
Published: July 2002

In this report, the first amphibian glucagon receptor (GluR) cDNA was characterized from the liver of the frog Rana tigrina rugulosa. Functional expression of the frog GluR in CHO and COS‐7 cells showed a high specificity of the receptor towards human glucagon with an EC50 value of 0.8±0.5 nM. The binding of radioiodinated human glucagon to GluR was displaced in a dose‐dependent manner only with human glucagon and its antagonist (des‐His1‐[Nle9‐Ala11‐Ala16]) with IC50 values of 12.0±3.0 and 7.8±1.0 nM, respectively. The frog GluR did not display any affinity towards fish and human GLP‐1s, and towards glucagon peptides derived from two species of teleost fishes (goldfish, zebrafish). These fish glucagons contain substitutions in several key residues that were previously shown to be critical for the binding of human glucagon to its receptor. By RT‐PCR, mRNA transcripts of frog GluR were located in the liver, brain, small intestine and colon. These results demonstrate a conservation of the functional characteristics of the GluRs in frog and mammalian species and provide a framework for a better understanding of the molecular evolution of the GluR and its physiological function in vertebrates.
Intraoperative blood salvage in abdominal uterine myomectomy
Authors: Yamada T. , Yamashita Y. , Terai Y. , Ueki M.
Published: July 2002

Objective: To study the safety and efficacy of intraoperative blood salvage in abdominal uterine myomectomy. Method: Thirty‐seven patients with a clinical diagnosis of uterine myoma who underwent abdominal uterine myomectomy were treated with an intraoperative blood salvage apparatus, Cell Saver, and compared with the patients without autotransfusion. Result: Thirty‐five patients received autologous blood transfusion alone and only two patients required additional homologous transfusion. The hemoglobin of processed and reinfused blood was proportional to the volume of intraoperative blood loss. There were no adverse reactions related to autologous transfusion. In the patients with more than 500 ml of blood loss, the mean blood loss volume in the Cell Saver group was higher than that in the control group, and the postoperative hemoglobin level was also higher. Conclusion: Intraoperative blood salvage was safe and certainly promising for patients with heavy blood loss during abdominal uterine myomectomy.
The promise of public/private sector collaboration in the development of vaginal microbicides
Authors: Gabelnick H.L. , Harper M.J.K.
Published: July 2002

This paper describes the efforts of the public sector, primarily the CONRAD Program and its Consortium for Industrial Collaboration in Contraceptive Research (CICCR), to work with industry in the development of vaginal microbicides for the prevention of transmission of STDs including HIV. The results of a meeting on this topic held in Durham, NC, USA in October 1998, as well as market surveys, are also included. The projects described illustrate the opportunities for collaboration and the resulting progress.
Uterine rupture in a multiparous woman during labor induction with oral misoprostol
Authors: Mathews J.E , Mathai M , George A
Published: July 2002

A multigravida with gestational diabetes, mild pregnancy‐induced hypertension and a previous curettage received four doses of misoprostol (100 μg) at three hourly intervals for induction of labor at term. Vaginal delivery of a live healthy baby occurred 1 h after the fourth dose. Hindwaters were bloodstained. Three hours later, she had excessive bleeding. Examination showed that the left lateral uterine wall had ruptured. She recovered after hysterectomy and blood transfusions.
Crustacean visual system: an investigation on glial cells and their relation to extracellular matrix
Authors: da Silva Simone Florim , Taffarel Marília , Allodi Silvana
Published: July 2002

Summry— Glial cells in higher invertebrate groups are usually recognized on the basis of their location and general morphological or functional criteria. In this study of the crustacean visual system, we have approached the analysis of the relations between glial cells and the extracellular matrix by classical histochemical methods for carbohydrates at the light and electron microscopic levels, carbonic anhydrase histochemistry and by the biochemical characterization of sulphated polysaccharides. Periodic acid—Schiff‐positive glial cells and processes were observed in the retina, basement membrane below the retina and in the optic ganglia. Carbonic anhydrase was not detected in the retina but it was demonstrated in all optic ganglia. The biochemical analysis of the extracellular matrix confirmed the alcian blue reaction and showed that sulphated polysaccharides are not abundant in the optic neuropils. This article describes into more details the crustacean visual system glial cells classification, and the relation between them and the extracellular matrix. In addition, they show that glial cells are the main components of the retinal basement membrane.
Histomorphological and proliferative characterization of developing periosteal neochondrocytes in vitro
Authors: Ito Yoichi , Sanyal Arunik , Fitzsimmons James S. , Mello Maria Alice , O'Driscoll Shawn W.
Published: July 2002

Periosteal chondrogenesis is relevant to cartilage repair and fracture healing. Cell proliferation is a limiting factor of cartilage production. We used an in vitro organ culture model to test the hypothesis that proliferative activity correlates with cell morphology. One hundred and four periosteal explants from 26 two‐month old New Zealand rabbits were cultured for up to 42 days. They were analyzed histomorphologically, and immunohistochemically with proliferative cell nuclear antigen (PCNA). The periosteal neocartilage displayed a consistent zonal pattern of chondrocyte cell shapes. The flat cell zone from day 7 to 21, consisted of uniform‐sized small spindle‐shaped cells. The round cell zone, which appeared on day 14, consisted of variable‐sized round cells averaging 510 ± 250 μm2 in area. They were subdivided into small round (<510 μm2) and large round cells (>510 μm2). The proliferative index was highest in the small round cell group (32 ± 6%), intermediate in the flat cell group (27 ± 6%), and lowest in the large round cell group (20 ± 7%) (P < 0.001). Furthermore, the proliferative indices in the round cell group were inversely proportional to cell size. Therefore, (1) there is a sequential progression of cell morphology during periosteal chondrogenesis, (2) cell differentiation is arrested prior to terminal differentiation for some cells and not for others, and (3) proliferative activity is strongly related to cell morphology. This organ culture model provides us with opportunities to study the regulation of terminal chondrocyte differentiation and the control of cell proliferation. This will contribute to our understanding of cartilage repair, fracture healing and growth plate physiology. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The effect of tibial lengthening using the Ilizarov method on the cartilage and the menisci of the knee joint
Authors: Fink Bernd , Schwinger Gerhard , Singer Joachim , Sager Martin , Wilke Christopher , Braunstein Stephan
Published: July 2002

In order to investigate possible acute damage to the knee joint cartilage and the menisci during tibial lengthening, sixteen young beagle dogs underwent 30% lengthening of the right tibia of 2.5 cm by callus distraction at a distraction rate of twice 0.5 mm per day. A further four dogs comprised the control group with fixator and osteotomy but without lengthening. After a distraction period of 25 days half the dogs were killed (group A) while the other half (eight dogs with limb lengthening and two dogs without) were killed after a further period of 25 days (group B). At the end of the study, the menisci were removed together with three cartilage‐bone cylinders from both femoral condyles from the weight‐bearing zones as well as from the corresponding tibial condyles. Serial sections from the menisci were stained with haematoxylin and eosin (H&E) and Elastica van Gieson. Sections of the cartilage‐bone cylinders were stained with H&E and safranin‐O. Cartilage thickness was measured and the glycosaminoglycan content of the joint cartilage was determined using microspectrophotometry. None of the histological preparations obtained from the untreated and distracted sides showed any signs of damage to the cartilage or to the menisci. There were no significant differences between cartilage thickness and proteoglycan content of the untreated side and the lengthened side. Thus, tibial lengthening using the Ilizarov method does not appear to cause acute damage to the cartilage of the knee joint or to the menisci. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Transforming growth factor alpha treatment alters intracellular calcium levels in hair cells and protects them from ototoxic damage in vitro
Authors: Staecker Hinrich , Dazert Stefan , Malgrange Brigitte , Lefebvre Philippe P. , Ryan Allen F. , Van De water Thomas R.
Published: July 2002

To determine if transforming growth factor alpha (TGFα) pretreatment protects hair cells from aminoglycoside induced injury by modifying their intracellular calcium concentration, we assayed hair cell calcium levels in organ of Corti explants both before and after aminoglycoside (i.e. neomycin, 10−3M) exposure either with or without growth factor pretreatment. After TGFα (500ng/ml) treatment, the intracellular calcium level of hair cells showed a five‐fold increase as compared to the levels observed in the hair cells of control cultures. After ototoxin exposure, calcium levels in hair cells of control explants showed an increase relative to their baseline levels, while in the presence of growth factors pretreatment, hair cells showed a relative reduction in calcium levels. Pretreatment of organ of Corti explants afforded significant protection of hair cell stereocilia bundle morphology from ototoxic damage when compared to explants exposed to ototoxin alone. This study correlates a rise in hair cell calcium levels with the otoprotection of hair cells by TGFα in organ of Corti explants.
Deterioration of parkinsonian symptoms following treatment of dopaminergic hallucinosis with olanzapine
Authors: Rudolf J. , Ghaemi M. , Schmülling S.
Published: July 2002

The atypical antipsychotic drug olanzapine has been proposed for treatment of dopaminergic psychosis in Parkinson's disease (PD). We report on a 68-year-old patient who developed a severe akinetic-rigid extrapyramidal syndrome, accompanied by additional paranoid symptoms, following olanzapine treatment of optic hallucinosis in PD. Olanzapine may also induce clinically relevant extrapyramidal side effects in PD patients.
Non‐invasive monitoring of pulmonary capillary wedge pressure in heart failure
Authors: Martins Susana , Soares Rui M. , Branco Luísa , Salomão Spencer , Antunes A. Mata
Published: July 2002

Objective:

To evaluate the usefulness of pulsed Doppler (PD) mitral flow E wave deceleration time (EDcT) to detect and quantify changes of pulmonary capillary wedge pressure (PCWP) in patients (pt) with dilated chronic heart failure (CHF) submitted to tailored therapy.

Methods:

In 14 pt with dilated cardiomyopathy (DCM) (59.4 ± 10.0 years, 11 males, sinus rhythm), admitted to the ICU because of worsening CHF, serial simultaneous hemodynamic and echocardiographic studies were performed (3–5/pt; overall 49 evaluations). PD mitral flow register was used to measure EDcT and correlated with PCWP at each study.

Results:

PCWP ranged from 36 to 3 mmHg (17.6 ± 8.8) and EDcT from 271 to 52 ms (104.9 ± 42.4). The correlation between EDcT and PCWP was −0.65 (PCWP = 31.7–0.134EDcT). Using this equation to calculate PCWP, individual absolute values difference (identity error — IE) was 5.6 ± 3.5 mmHg (0.4–14.6). In 29 cases (59.2%) IE was > 5 mmHg, defined as major error. Considering EDcT percent change (Δ%EDcT) and PCWP variation (ΔPCWP) in serial evaluations, we found a correlation of −0.87 (ΔPCWP = −2.83–0.19 Δ%EDcT). Using this equation, the IE was 2.3 ± 1.6 mmHg (0–5.2) and there were only two (6%) major errors (P < 0.0001).

Conclusions:

In pt with DCM and advanced CHF, EDcT shows a reasonable correlation with PCWP, but when it is used to calculate PCWP the IE to hemodynamic values is often large. However, our results with EDcT percent change in serial evaluations using a first simultaneous invasive determination, suggest that this technique is reliable for monitoring PCWP and can be particularly useful for pt submitted to tailored therapy.
Experience of commencing Carvedilol in elderly patients with heart failure in a routine outpatient clinic
Authors: Owen Andrew
Published: July 2002

Carvedilol has been shown to be beneficial for patients with heart failure, but it is not clear how it should be initiated in routine clinical practice, particularly in the elderly. This study is a retrospective review of 19 patients of age 80±4 years with heart failure, who had Carvedilol treatment initiated in a routine outpatient clinic. No patient experienced a worsening of their heart failure or required admission to hospital. There was a mean reduction in heart rate of 11 beats/min. Carvedilol was tolerated by 68% of the patients. Thus, Carvedilol can be safely initiated in a routine outpatient clinic in appropriately selected elderly patients.
Screening, endpoint classification, and safety monitoring in the Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure (MERIT‐HF)
Authors: Fagerberg Björn
Published: July 2002

The MERIT‐HF study was designed to investigate the effect of once‐daily dosing of metoprolol succinate CR/XL added to standard therapy in patients with chronic heart failure. A screening programme, aiming at identifying eligible patients for the study was used by 231 out of 313 sites, resulting in 8912 screened patients. These patients were older, more often women, had marginally higher ejection fraction and were more often in NYHA class IV compared to the finally randomised patients. There was a positive correlation between the number of screened and randomised patients and due to the high inclusion rate the number of randomised patients was increased from 3200 to 3991 patients. The clinical events were defined by a manual and were based on identical classifications made independently by two members of an Independent Endpoint Committee. Data from the case report form and the classifications made by the Endpoint Committee were in accordance for hospitalisation due to worsening heart failure on 722 occasions. On 207 occasions the data from the case report forms and the classification made by the committee differed regarding this clinical event. The Independent Safety Committee monitored safety aspects of the study by using asymmetric group sequential procedures. The study was stopped early on recommendation from the Independent Safety Committee, when the second pre‐specified interim analysis (50% of total number of expected deaths) showed that the criterion for stopping due to benefit had been met and exceeded. In conclusion, a screening programme facilitated patient recruitment and showed the characteristics of the background population, the event classification was improved by using an independent endpoint committee, and the safety monitoring allowed an early closure of the study due to mortality benefit, without jeopardising the final analyses of the results.
Tezosentan (an intravenous endothelin receptor A/B antagonist) reduces peripheral resistance and increases cardiac power therefore preventing a steep decrease in blood pressure in patients with congestive heart failure
Authors: Gad Cotter , Wolfgang Kiowski , Edo Kaluski , Isaac Kobrin , Olga Milovanov , Alon Marmor , Jamal Jafari , Leonardo Reisin , Ricardo Krakover , Zvi Vered , Avi Caspi
Published: July 2002

Objective:

This study investigated the effect of tezosentan (an intravenous endothelin‐1 receptor antagonist) on vascular resistance and cardiac function and determined the dose response in patients with stable congestive heart failure (CHF) due to left ventricular systolic dysfunction.

Methods:

In a double‐blind fashion, tezosentan or placebo were administered in ascending doses (5, 20, 50, 100 mg h−1) to 38 CHF (NYHA class III) patients with ejection fraction ≤35%, cardiac index ≤2.7 l min−1 m−2 and pulmonary capillary wedge pressure ≥ 15 mmHg. Systemic vascular resistance index (SVRi) was estimated as mean arterial blood pressure [(MAP‐right atrial pressure)÷cardiac index (CI)]. Cardiac function was assessed as cardiac power index (Cpi), calculated as pressure × flow (MAP × CI), where MAP represents pressure and CI represents cardiovascular flow.

Results and discussion:

Compared to the placebo, tezosentan induced a dose‐dependent decrease in SVRi (−32%), an increase in Cpi (+20%) and a small decrease in MAP (−9%). By contrast, patients treated with nitrate vasodilators or nesiritide (a natriuretic peptide) showed a decrease in SVRi not accompanied by a significant increase in Cpi leading to a steep decrease in MAP.

Conclusions:

The use of Cpi in the assessment of the hemodynamic effects of tezosentan, provides a useful alternative characterization of the complex influences of vasodilators on cardiac function in patients with CHF.
Evidence‐Based Care and the Breastfeeding Couple: Key Concerns
Authors: Auerbach Kathleen G.
Published: July 2002

Optimal health care is based on evidence that a) no harm is done when that care is provided and that b) the care provided assists in the prevention of further problems or the resolution of the presenting problem. Too often, care provided to lactating mothers and their breastfeeding offspring lacks evidence supportive of the techniques used or care provided. This article addresses 10 common hospital‐based practices and reviews documented evidence related to their effect on breastfeeding success. Concepts pertaining to the breasts and breastfeeding that require incorporation into the educational offerings of current and future health care providers are also identified.
FOSTERING EVIDENCE‐BASED CARE IN CLINICAL TEACHING
Authors: Erickson‐Owens Debra A. , Kennedy Holly Powell
Published: July 2002

Understanding scientific research evidence and applying it to clinical practice is a focus in today's health care arena. Fostering evidence‐based care (EBC) in clinical teaching is an effective way to help students learn to think critically, search for, evaluate, and incorporate the best research evidence into their clinical practice. For example, helping a student plan care for a woman creates a “teaching moment” for the application of scientific evidence to clinical practice. Essentially, EBC is a learned skill for both the student and the clinical teacher. It requires intellectual curiosity and a willingness to explore beyond “the way it has always been done.” This article presents a review of the goals of clinical teaching, strategies to foster EBC, and tools to assess the readiness of the teacher, the student, and the clinical setting for EBC. By aligning the goals of clinical teaching with evidence‐based strategies, both the educator and student strive together to provide midwifery care that is supported by available research.
FROM NURSING OUTPOSTS TO CONTEMPORARY MIDWIFERY IN 20TH CENTURY CANADA
Authors: Plummer Kate
Published: July 2002

Knowledge of the history of one's profession is always related to the informed practice of the profession and can aid midwifery in its expansion and recognition. Understanding the long and diverse history of Canadian midwifery expands the appreciation by midwives in the United States of midwifery north of our border, which, although newly regulated, has much experience to share. This article documents the evolution of midwifery in Canada during the 20th century. Government‐sanctioned midwifery prior to 1991, the year when Ontario passed legislation to regulate midwifery for the first time in modern Canadian history, was limited to isolated, usually northern, frontier and outpost regions of Canada, but the providers who practiced it were well‐educated and important figures in the broader history of midwifery.
The Permeability of Novel Hybrid Fiber Composite Material for Use as Diesel Particulate Filters
Authors: Houston Alastair J. , Boubert Douglas , Clyne Trevor William
Published: July 2020

An investigation is presented into modeling of gas flow through particle/fiber hybrid composite materials designed for use as diesel particulate filters (DPFs). The work leads to the creation of a modified version of the Carman–Kozeny equation, specifically tailored for such structures. Details of computational fluid dynamics (CFD) simulation of gas flow through modeled structures are provided, leading to formulations to account for the loss of surface area associated with sintering and a tortuosity effect dependent on the porosity level. Based on these outcomes, a simple analytical expression is derived, and it is shown that predicted permeability values obtained with it are in good agreement with experimental data.
Formate Dehydrogenase from Rhodococcus jostii (RjFDH) – A High‐Performance Tool for NADH Regeneration
Authors: Boldt Alexander , Ansorge‐Schumacher Marion B.
Published: July 2020

The use of formate dehydrogenases (FDHs) for regeneration of the important cofactor NADH in enzyme‐catalysed synthetic reactions has several advantages over alternative systems. However, a major bottleneck for broad industrial applications is the low specific activity of the currently used FDHs. In this study, we introduce a novel NAD‐dependent formate dehydrogenase from Rhodococcus jostii (RjFDH) with both high specific activity and stability. The enzyme was identified in a targeted database research and recombinantly obtained from Escherichia coli. RjFDH is a homodimer with a monomeric molecular mass of 44.7 kDa. The homology model shows that all amino acid residues of the NAD‐dependent formate dehydrogenases are usually concerned with catalytic activity, substrate acceptance, and cofactor binding. The only substrate oxidised by these enzymes is formate. RjFDH had a specific activity of 19.9 U mg−1 at 22 °C along with unimpaired activity and high stability over a broad pH range. The Km values for formate and NAD+ were 7.3 and 0.098 mmol L−1, respectively. The optimum temperature was found to be 50 °C, at which the enzyme activity increased to about 318%. Both activity and thermal stability were higher than those of the FDH from Candida boidinii (CbFDH), which is the standard enzyme currently in use for cofactor regeneration. Different solvents roughly had the same impact on the activity and stability of both RjFDH and CbFDH. The superior performance of RjFDH over CbFDH as a regeneration system for NADH was demonstrated for the synthesis of L‐tert‐leucine as well as (S)‐1‐phenylethanol. In both systems, the concentration of RjFDH used was only one‐third of the concentration of CbFDH required to achieve comparable conversion rates. Rational designing provided a promising NADP‐accepting variant. Thus, RjFDH has a great potential to serve as an alternative system for NADH regeneration in enzyme‐catalysed synthetic reactions.

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Merging Electrosynthesis and Bifunctional Squaramide Catalysis in the Asymmetric Detrifluoroacetylative Alkylation Reactions
Authors: Chang Xihao , Zhang Jiayin , Zhang Qinglin , Guo Chang
Published: July 2020

An enantioselective bifunctional squaramide‐catalyzed detrifluoroacetylative alkylation reaction has been developed under electrochemical conditions. The unified strategy based on this key tandem methodology has been divergently explored for the asymmetric synthesis of fluorine‐containing target molecules with good stereocontrol (up to 95 % ee). Furthermore, this asymmetric catalytic reaction combines the benefits of electrosynthesis and organocatalysis for the preparation of biologically relevant products containing C‐F tertiary stereogenic centers.
Guest‐Responsive Reversible Electron Transfer in a Crystalline Porous Framework Supported by a Dynamic Building Node
Authors: Sikdar Nivedita , Hazra Arpan , Samanta Debabrata , Haldar Ritesh , Maji Tapas Kumar
Published: July 2020

We demonstrate a redox‐active, crystalline donor–acceptor (D‐A) assembly in which the electron transfer (ET) process can be reversibly switched. This ET process, induced by a guest‐responsive structural transformation at room temperature, is realized in a porous, metal–organic framework (MOF), having anthracene (D)–naphthalenediimide (A) as struts. A control MOF structure obtained by a solvent‐assisted linker exchange (SALE) method, replacing an acceptor strut with a neutral one, supported the switchable electronic states in the D‐A MOF. Combined investigations with X‐ray diffraction, spectroscopy, and theoretical analyses revealed the dynamic metal paddle‐wheel node as a critical unit for controlling structural flexibility and the corresponding unprecedented ET process.
Universal Access to Two‐Dimensional Mesoporous Heterostructures by Micelle‐Directed Interfacial Assembly
Authors: Wang Jie , Chang Zhi , Ding Bing , Li Tao , Yang Gaoliang , Pang Zhibin , Nakato Teruyuki , Eguchi Miharu , Kang Yong‐Mook , Na Jongbeom , Guan Bu Yuan , Yamauchi Yusuke
Published: July 2020

Two‐dimensional (2D) mesoporous heterostructures combining ultrathin nanosheet morphology, periodic porous surface structures, and diverse hybrid compositions have become increasingly important for renewable energy storage and electronics. However, it remains a great challenge to develop a universal method to prepare 2D mesoporous heterostructures. Herein, we report a composite‐micelle‐directed interfacial assembly method to synthesize heterostructures of an ultrathin 2D material covered with mesoporous monolayers assembled on both sides. To demonstrate the concept, we first fabricated a new sandwichlike carbon@MXene@carbon mesoporous heterostructure through the self‐assembly of exfoliated MXene nanosheets and block copolymer F127/melamine‐formaldehyde resin composite micelles and subsequent thermal treatment. Finally, we demonstrate that the carbon@MXene@carbon mesoporous heterostructured nanosheets manifest remarkably enhanced electrochemical performance as a cathode material for lithium–sulfur batteries.
Coupling a Wireless Bipolar Ultramicroelectrode with Nano‐electrospray Ionization Mass Spectrometry: Insights into the Ultrafast Initial Step of Electrochemical Reactions
Authors: Hu Jun , Zhang Nan , Zhang Pan‐Ke , Chen Yun , Xia Xing‐Hua , Chen Hong‐Yuan , Xu Jing‐Juan
Published: July 2020

We report a new mass spectrometric method for detecting electrogenerated intermediates. This approach is based on simultaneous activation of electrospray ionization and redox reaction on a wireless bipolar ultramicroelectrode, which is fabricated in the tip of a quartz nanopipette. The hollow structure of the ultramicroelectrode permits rapid transferring the transient species from electrode–electrolyte interfaces into the gas phase for mass spectrometric identification on the time scale of microseconds. The long‐sought fleeting intermediates including TPrA.+, whose lifetime in solution is only 200 μs, and catecholamine o‐semiquinone radicals, the second‐order rate constant of which is typically 109 m−1 s−1, were successfully identified, helping clarify the previously hidden reaction pathways. Accordingly, our method may have wide applicability in exploring the dynamics of many electrochemical reactions, especially their ultrafast initial steps.
Raman imaging for measuring homogeneity of dry binary blend: Combining microscopy with spectroscopy for technologists
Authors: Gupta Vivek , Pathak Devesh K. , Chaudhary Sandeep , Kumar Rajesh
Published: July 2020

Expanding the capabilities of Raman scattering as an analytical tool for engineering applications can optimize the technological output immensely. Understanding the homogeneity of any blended mix is one such significant parameter in the family of composite building construction materials that needs an appropriate tool for its measurement. Raman spectromicroscopy has been established here for the purpose of studying the chemical homogeneity at the microscopic scale of a dry binary blend used in the building constructions as an example. In this study, two waste stone powdered materials, obtained from western Indian stone fields, have been characterized in their respective unmixed forms using Raman spectroscopy up to an extent so that the same can be developed as a microscopic tool to clearly “see” the chemical homogeneity of a mixture. A step‐by‐step study has been carried out by first, simply making a physically separated and identifiable boundary of the two materials followed by obtaining a Raman line image. The Raman line map could clearly identify the boundary, which otherwise was not possible to appreciate visibly. The same recipe has been extended to study the homogeneity of a binary mixture (blended in 1:1 ratio), using a Raman area map. The novelty of the work lies in the advancement in the analytical tool's family to see the chemical homogeneity of building construction materials at the microscopic level. Chemical imaging using Raman spectroscopy has been demonstrated as a simple tool to understand the homogeneity of the dry binary blend, which was not possible by other simple techniques. Using Raman area mapping proves to be a quick, valuable, and effective tool for measuring the homogeneity of the blended mixes at the microscopic scale and important for application in building construction materials.
Synthesis and characterization of silica‐coated Fe3O4 nanoparticle@silylpropyl triethylammonium polyoxometalate as an organic–inorganic hybrid heterogeneous catalyst for the one‐pot synthesis of tetrahydrobenzimidazo[2,1‐b]quinazolin‐1(2H)‐ones
Authors: Moussa Alkassoume , Rahmati Abbas
Published: July 2020

In this study, silica‐coated Fe3O4 nanoparticle@silylpropyl triethylammonium polyoxometalate catalyst was fabricated and characterized using atomic absorption, inductively coupled plasma optical emission spectrometry, elemental analysis, thermogravimetric analysis, Fourier‐transform infrared, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and vibrating sample magnetometry analyses. The activity of this catalyst was examined in the synthesis of tetrahydrobenzimidazo[2,1‐b]quinazolin‐1(2H)‐ones. The bonding of the polyoxometalate to the surface of the nanoparticles exhibited excellent catalytic activity in this synthesis. Besides, the catalyst showed good reusability and recovery from the reaction mixture. Tetrahydrobenzimidazo[2,1‐b]quinazolin‐1(2H)‐ones were synthesized in high yields in the presence of inexpensive supported solid acid catalysts under classical heating conditions.
Water based blowing agents for rubber extrusion
Authors: Hopmann Christian , Kammer Sebastian , Facklam Martin
Published: July 2020

Physiologically hazardous chemical blowing agents are state of the art for the foaming of extruded rubber profiles. Water is a potential alternative to these blowing agents and is incorporated into rubber compounds in the form of water‐leaded hygroscopic substances such as carbon blacks, silica, or hydrates. To achieve an optimum foaming result, the water desorption and cross‐linking reaction has to be coordinated. In thermogravimetric investigations it is found that the inertia of the evaporation process plays an important role in water desorption mechanisms. It turned out that manual conditioning of the hygroscopic fillers with water is not reproducible. As a consequence, measurement uncertainties in characterization resulted, so that statistical proof of the expected effects on water desorption due to the specific properties of the fillers (e.g., silanol group density, specific surface area) could not be provided. However, carbon blacks are less suitable than silica due to the lower desorption temperature. The precipitated silica Ultrasil 360 with a relatively high pH‐value showed higher water desorption rates than the other silica. The desorption temperature can reproducibly be adjusted as required by a suitable choice of hydrate. Since the absolute amount of water in the rubber compound is crucial to the foaming behavior during vulcanization Karl Fischer titration is used to determine the water content of a polar and a nonpolar rubber compound is determined over several weeks. Depending on the climatic conditions during storage, large deviations from the amount of incorporated water occur especially for polar rubber compounds such as nitrile butadiene rubber.
Polylactic acid and high‐density polyethylene blend: Characterization and application in additive manufacturing
Authors: Harris Muhammad , Potgieter Johan , Ray Sudip , Archer Richard , Arif Khalid Mahmood
Published: July 2020

This research reports a novel polylactic acid (PLA) blend with high density polyethylene (HDPE) and polyethylene graft maleic anhydride (PE‐g‐MAH) to mitigate the PLA degradation issues associated with high temperatures, soil and water exposure. The blend was prepared with a melt blending process and directly printed with a custom‐built pellet printer to maintain the “as prepared” properties. Thermal stability was analyzed in terms of mechanical strength at different bed temperatures and postprinting aging for 10 days. Soil burial degradation and water absorption were investigated in terms of mechanical strength and effects on mass at three intervals (15, 30, 45 days). The proposed blend revealed high stability to all three degradation mechanisms due to the chemical grafting along with physical interlocking. Finally, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to confirm the enhancement in molecular interactions, melt crystallization, onset temperatures and phase distribution, respectively.
Nitrogen‐Rich Hierarchical Porous Carbon Prepared by Sol‐Gel Assisted Inorganic Template Methods for Supercapacitors
Authors: Jin Yan , Qian Meng , Lin Gaoxin , Zhang Shaoning , Dong Wujie , Huang Fuqiang
Published: July 2020

Nitrogen‐rich and porous carbon materials have attracted great attention for supercapacitors due to the relatively large specific surface area, highly active N species and good electrical conductivity. However, it is still a challenge to precisely regulate the above characteristics simultaneously. Here artful sol‐gel‐assisted inorganic template methods are proposed by using melamine and polyethylene glycol (PEG) as complement and magnesium nitrate as inorganic salt to prepare nitrogen‐rich hierarchical porous carbon with three different pore structure (1.75 nm, 3.8 nm and 9.07 nm), giving the opportunity to regulate the specific surface area and pore size distribution of the carbon materials. The designer porous carbon possesses more than 9 at. % of the pyridinic nitrogen (N‐6) and pyrrolic nitrogen (N‐5), a high specific surface area of 917.0 m2 g−1 and good electrical conductivity (1.28 S cm−1). All these factors result in a specific capacitance up to 371 F g−1 at 1 A g−1 and excellent cycle stability (retain 98.3 % capacitance after 10000 cycles).
The transition from objectively structured practical examination (OSPE) to electronic OSPE in the era of COVID‐19
Authors: Dutta Atanu Kumar , Goswami Kalyan , Murugaiyan Sathishbabu , Sahoo Sibasish , Pal Amit , Paul Chandramallika , Thallapaneni Sasikala , Biswas Soham
Published: July 2020

The coronavirus (COVID‐19) pandemic is forcing the medical educators to innovate and embrace online education and assessment platform. One of the most significant challenges we are facing is the formative assessment of practical skills in the undergraduate medical biochemistry education. We have designed the electronic objectively structured practical examination to facilitate the formative assessment.
A quick UPLC–MS/MS method for therapeutic drug monitoring of abiraterone and delta(4)‐abiraterone in human plasma
Authors: Weiss Thaís Luise Dillenburg , Furtado Carolina Mesquita , Antunes Marina Venzon , Gössling Gustavo , Schwartsmann Gilberto , Linden Rafael , Verza Simone Gasparin
Published: July 2020

Abiraterone acetate efficacy against prostate cancer is dependent on the circulating levels of abiraterone and its active metabolites, which present significant pharmacokinetic variability among patients. Thus, therapeutic drug monitoring can be performed to improve treatment outcomes. To support such studies, there are only a limited number of bioanalytical methods in current literature. This work presents a fast method to quantify abiraterone and D4A in plasma in 4 min by UPLC–MS/MS. Bioanalytical method validation was performed according to the recommendations of the US Food and Drug Administration. The method was linear within the range of 1–400 ng/ml for abiraterone and 0.2–20 ng/ml for D4A (r2 > 0.99). Based on the analysis of quality control samples at the lower limit of quantification, low, medium and high concentrations, the method was precise (CVabiraterone ≤ 9.72%; CVD4A ≤ 14.64%) and accurate (CVabiraterone 95.51–107.59%; CVD4A 98.04–99.89%). Application of the method to the quantification of abiraterone and D4A in 10 clinical samples revealed important variability in the conversion ratio of abiraterone to D4A (CV 90.85%). Considering the current literature, this is the fastest method to quantify abiraterone and D4A in plasma, allowing for optimization of the analytical routine.
Appraisal of urgent transcatheter aortic valve replacement
Authors: Kornowski Ran
Published: July 2020

Key Points

Urgent transcatheter aortic valve replacement (TAVR) is needed in unstable patients with severe aortic stenosis and acute decompensated heart failure who are refractory to initial medical management.

The outcome of urgent TAVR is worse and heavily influenced by the severity of the clinical status prior to intervention.

Careful patient evaluation, procedural planning, and postoperative management should be optimized to improve the clinical results.
Can percutaneous coronary interventions be performed safely in leukemia patients?
Authors: Grines Cindy L. , Cox David
Published: July 2020

Key Points

Patients with leukemia are often denied percutaneous coronary intervention (PCI), and those who do undergo PCI are older and sicker.

There is a minor increase in vascular complications and no increase in retroperitoneal bleeds, suggesting transfusions may be given for reasons unrelated to the PCI.

Since cardiac complications are not increased in leukemia patients, the increased mortality observed in after PCI in acute leukemia may be related more to underlying malignancy.
Belt and suspenders: Why it pays to protect and cover during carotid stenting
Authors: Hering Dagmara , Heuser Richard R.
Published: July 2020

Key Points

Carotid stenting results show equivalence to carotid endarterectomy.

Most patients undergoing carotid intervention are asymptomatic.

Using embolic protection with a covered mesh stent shows promise in this first large multicenter study.