bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of gene expression data using self‐organizing maps
Authors: Törönen Petri , Kolehmainen Mikko , Wong Garry , Castrén Eero
Published: July 2002

DNA microarray technologies together with rapidly increasing genomic sequence information is leading to an explosion in available gene expression data. Currently there is a great need for efficient methods to analyze and visualize these massive data sets. A self‐organizing map (SOM) is an unsupervised neural network learning algorithm which has been successfully used for the analysis and organization of large data files. We have here applied the SOM algorithm to analyze published data of yeast gene expression and show that SOM is an excellent tool for the analysis and visualization of gene expression profiles.
Structure‐function analysis of a double‐mutant cystic fibrosis transmembrane conductance regulator protein occurring in disorders related to cystic fibrosis
Authors: Fanen Pascale , Clain Jérôme , Labarthe Régis , Hulin Philippe , Girodon Emmanuelle , Pagesy Patrick , Goossens Michel , Edelman Aleksander
Published: July 2002

A number of disorders related to cystic fibrosis have been described since the cloning of the cystic fibrosis gene, including infertility due to the congenital bilateral absence of the vas deferens. We have identified, in several patients, complex cystic fibrosis transmembrane conductance regulator genotypes like double‐mutant alleles. We have now analyzed the structure‐function relationships of one of these mutants, R74W‐D1270N cystic fibrosis transmembrane conductance regulator, expressed in HeLa cells, to evaluate the contribution of each mutation in the phenotype. We found that R74W cystic fibrosis transmembrane conductance regulator appears to be a polymorphism, while D1270N cystic fibrosis transmembrane conductance regulator could be responsible for the congenital bilateral absence of the vas deferens phenotype. The combination of the two produced a more severe effect on the chloride conductance pathway as well as on the phenotype.
Nitrogen dioxide radical generated by the myeloperoxidase‐hydrogen peroxide‐nitrite system promotes lipid peroxidation of low density lipoprotein
Authors: Byun Jaeman , Mueller Dianne M. , Fabjan Judith S. , Heinecke Jay W.
Published: July 2002

Myeloperoxidase, a heme protein secreted by activated phagocytes, is present and enzymatically active in human atherosclerotic lesions. In the current studies, we explored the possibility that reactive nitrogen species generated by myeloperoxidase promote lipid peroxidation of low density lipoprotein (LDL) – a modification that may render the lipoprotein atherogenic. We found that myeloperoxidase, an H2O2‐generating system and nitrite (NO2
−) peroxidized LDL lipids. The process required NO2
− and each component of the enzymatic system; it was inhibited by catalase, cyanide and ascorbate, a potent scavenger of aqueous phase radicals. LDL peroxidation did not require chloride ion, and it was little affected by the hypochlorous acid scavenger taurine. Collectively, these results suggest that lipid peroxidation is promoted by a nitrogen dioxide radical‐like species. These observations indicate that myeloperoxidase, by virtue of its ability to form reactive nitrogen intermediates, may promote lipid peroxidation and atherogenesis.
The trefoil peptides TFF2 and TFF3 are expressed in rat lymphoid tissues and participate in the immune response
Authors: Cook G.A. , Familari M. , Thim L. , Giraud A.S.
Published: July 2002

Members of the trefoil factor (TFF) family are mucin‐associated polypeptides that are expressed along the entire length of the gastrointestinal tract. TFFs have been proposed to play a role in mucosal defence through both protective and reparative mechanisms. The potential relationship between TFFs and mucins in non‐gut glycoprotein‐secreting epithelia has not been fully explored. In the present study we identified TFF2 and TFF3 mRNA and peptide in rat lymphoid tissues, demonstrated that TFF peptide expression in rat spleen increased 1.5‐ to 3‐fold following experimental induction of the immune response, and showed that hTFF2 and hTFF3 (1–5 mg/ml) stimulated migration of human monocytes. Our data suggest that TFFs may in part be involved in the repair of injury through the modulation of the inflammatory response.
Analysis of the domain structure of elongation factor‐2 kinase by mutagenesis
Authors: Diggle Tricia A , Seehra Charnjit K , Hase Saiki , Redpath Nicholas T
Published: July 2002

A number of elongation factor‐2 kinase (eEF‐2K) mutants were constructed to investigate features of this kinase that may be important in its activity. Typical protein kinases possess a highly conserved lysine residue in subdomain II which follows the GXGXXG motif of subdomain I. Mutation of two lysine residues, K340 and K346, which follow the GXGXXG motif in eEF‐2K had no effect on activity, showing that such a lysine residue is not important in eEF‐2K activity. Mutation of a conserved pair of cysteine residues C‐terminal to the GXGXXG sequence, however, completely inactivated eEF‐2K. The eEF‐2K CaM binding domain was localised to residues 77–99 which reside N‐terminal to the catalytic domain. Tryptophan 84 is an important residue within this domain as mutation of this residue completely abolishes CaM binding and eEF‐2K activity. Removal of approximately 130 residues from the C‐terminus of eEF‐2K completely abolished autokinase activity; however, removal of only 19 residues inhibited eEF‐2 kinase activity but not autokinase activity, suggesting that a short region at the C‐terminal end may be important in interacting with eEF‐2. Likewise, removal of between 75 and 100 residues from the N‐terminal end completely abolished eEF‐2K activity.
In vitro formation of S‐nitrosohemoglobin in red cells by inducible nitric oxide synthase
Authors: Mamone Gianfranco , Sannolo Nicola , Malorni Antonio , Ferranti Pasquale
Published: July 2002

The present study demonstrates that NO produced in vitro by inducible nitric oxide synthase in red cells can convert hemoglobin contained in the red cells to S‐nitrosohemoglobin. Experiments carried out either in the absence or in the presence of a low molecular weight thiol, such as cysteine, showed that in the first case the target of NO is heme‐Fe2+. On the contrary, in the presence of cysteine, the first step is the formation of S‐nitrosocysteine, followed by transfer of the NO group to a particular cysteine residue of β‐globin, cysteine 93. These results confirm previous data indicating the preferential formation of S‐nitrosohemoglobin at that site by chemical methods [Ferranti et al. (1997) FEBS Lett. 400, 17–24], and the existence of a physiological mechanism of inactivation for NO circulating in blood. The analysis of S‐nitrosohemoglobin can also allow the quantification of the NO levels in blood to be applied for in vitro and in vivo measurements.
Subtotal hysterectomy for uterine rupture
Authors: Thakur A , Heer M.S , Thakur V , Heer G.K , Narone J.N , Narone R.K
Published: July 2002

Objective: The aim of this paper was to stratify patients with uterine rupture in extremis (with hypotension, change in vital organ function, and altered mental status) and evaluate outcome for patients undergoing subtotal hysterectomy (STH) vs. uterine repair (UR). Methods: Of 39 667 hospital deliveries between 1993 and 1998 at a university hospital, 367 presented with uterine rupture. Of these, 96 presented in extremis and had an irregularly torn uterus found at operation. Charts were retrospectively reviewed to stratify patient population with uterine rupture and their outcome. Results were analyzed using Fisher's exact test. Results: Patients with uterine rupture were 31–35 years old, para≥3, had received no antenatal care, and presented with rupture in the lower uterine segment. Sixty‐one patients underwent STH while 35 underwent UR. The groups were similar with respect to patient age, parity, cause of rupture, and clinical condition at the time of evaluation (P=0.2). The operative time for STH was significantly less than UR, 35 min vs. 75 min (P<0.01). Maternal mortality was significantly higher in patients undergoing UR vs. STH, 46% vs. 20% (P=0.01). Maternal morbidity occurred in 30% of patients undergoing STH vs. 50% in patients undergoing UR (P=0.01). The time to discharge was significantly less in patients undergoing STH compared to UR, 14.5 days vs. 27 days (P<0.01). Conclusions: Patients with uterine rupture in extremis tend to be young, multiparous, receive no antenatal care, and have uterine rupture of the lower segment. STH significantly lowered operative time, morbidity, time to discharge, and mortality than UR in patients in extremis with uterine rupture.
Utilization of intravenous nitroglycerin for obstetrical emergencies
Authors: Vinatier D. , Dufour P. , Bérard J.
Published: July 2002

Objective: The authors investigated, by reviewing publications and their personal experience, opportunities for the use of nitroglycerin to manage several obstetric emergencies. Methods: A retrospective study of 10 observations of internal podalic versions of the second non‐vertex twin, with administration of intravenous nitroglycerine, performed between August 1994 and March 1996, was undertaken. The authors compared their results with those reported elsewhere. The indications of nitroglycerin have been extended to intrapartum external version of the second twin, retained placenta, and uterine inversion. Results: Only one failure of internal podalic version due to failure of uterine relaxation was observed. Conclusion: From both experience and published reports it was confirmed that intravenous nitroglycerin (NTG) injection induces a transient and prompt uterine relaxation without affecting maternal and fetal prognosis.
Community loan funds and transport services for obstetric emergencies in northern Nigeria
Authors: Essien E , Ifenne D , Sabitu K , Musa A , Alti‐Mu'azu M , Adidu V , Golji N , Mukaddas M
Published: July 2002

Preliminary studies: Focus group discussions and a community survey indicated that inadequate funds and transport caused delays in deciding to seek emergency obstetric care and in reaching facilities. Interventions: Following improvements in the quality of obstetric services, a community loan program was established in early 1995. Community members determined its features: compulsory contributions; community administration; loans for obstetric complications only; no interest; a 6‐month grace period; and 24‐month repayment. A transport system was also established, in which private vehicle drivers agreed to respond to calls for emergency transport and charge a set fee. Results: The equivalent of US $20 500 was collected from 81 annual and 2273 one‐time contributors. Eighteen loans were approved in 9 months. Repayment data are not yet available. For the transport system, 23 drivers pledged permanent participation and 58 pledged to take part in 6‐month rotations. They transported 18 women. Costs: The cost of these interventions was $3409 for the loan fund and $2272 for the transport system. Sixty percent of the cost was paid by the community and the rest by the PMM project. Conclusions: Community‐managed loan and transport systems for women with obstetric emergencies can be established and may contribute to reducing delay in obtaining emergency obstetric care. © 1997 International Federation of Gynecology and Obstetrics
Proliferation of mitochondria and gene expression of carnitine palmitoyltransferase and fatty acyl‐CoA oxidase in rat skeletal muscle, heart and liver by hypolipidemic fatty acids
Authors: Totland Geir K. , Madsen Lise , Klementsen Beate , Vaagenes Hege , Kryvi Harald , Frøyland Livar , Hexeberg Sofie , Berge Rolf K.
Published: July 2002

Morphological and biochemical effects were induced at the subcellular level in the skeletal muscle, heart and liver of male rats as a result of feeding with EPA, DHA, and 3‐thia fatty acids. The 3‐thia fatty acid, tetradecylthioacetic acid (TTA) and EPA induced mitochondrial growth in type I muscle fibers in both the diaphragm and soleus muscle, and the size distribution of mitochondrial areas followed a similar pattern. Only the 3‐thia fatty acid induced mitochondrial growth in type II muscle fibers. The mean area occupied by the mitochondria and the size distribution of mitochondrial areas in both fiber types were highly similar in DHA‐treated and control animals. Only the 3‐thia fatty acid increased the gene‐expression of carnitine palmitoyltransferase (CPT)‐II in the diaphragm. In the heart, however, the gene expression decreased. In hepatocytes an increase in the mean size of mitochondria was observed after EPA treatment, concomitant with an increase in mitochondrial CPT‐II gene expression. Administration of 2‐methyl‐substituted EPA (methyl‐EPA) induced a higher rate of growth of mitochondria than EPA. At the peroxisomal level in the hepatocytes a 3‐thia fatty acid, EPA, and DHA increased the areal fraction concomitant with the induction of gene expression of peroxisomal fatty acyl‐CoA oxidase (FAO). In the diaphragm, mRNA levels of FAO were not affected by EPA or DHA treatment, whereas gene expression was significantly increased after 3‐thia fatty acid treatment. In the heart, both 3‐thia fatty acid, EPA and DHA tended to decrease the levels of FAO mRNA. The areal fraction of fat droplets in all three tissue types was significantly lower in the groups treated with 3‐thia fatty acid. In the group treated with EPA a lower areal fraction of fat droplets was observed, while the DHA group was similar to the control. This indicates that EPA and DHA have different effects on mitochondrial biogenesis.
In vivo microdialysis and immunohistochemical analyses of tendon tissue demonstrated high amounts of free glutamate and glutamate NMDAR1 receptors, but no signs of inflammation, in Jumper's knee
Authors: Alfredson Håkan , Forsgren Sture , Thorsen Kim , Lorentzon Ronny
Published: July 2002

This investigation describes, to our knowledge, the first experiment where the microdialysis technique was used to study certain metabolic events in human patellar tendons in combination with immunohistochemical analyses of tendon biopsies. In five patients (four men and one woman) with a long duration (range 12‐36 months) of pain symptoms from Jumper's knee (localized tenderness in the patellar tendon verified as tendon changes with ultrasonography or MRI), and in five controls (four men and one woman) with normal patellar tendons, a standard microdialysis catheter was inserted into the patellar tendon under local anestesia. The local concentrations of glutamate (excitatory neurotransmitter) and prostaglandin E2 (PGE2) were registered under resting conditions. Samplings were done every 15 min during a 2 h period. In all individuals (patients and controls) biopsies were taken for immunohistochemical analyses.

The results showed that it was possible to detect and measure the concentrations of glutamate and PGE2 in the patellar tendon with the use of microdialysis technique. There were significantly higher concentrations of free glutamate, but not PGE2, in tendons with tendinosis compared to normal tendons. In the biopsies, there were no inflammatory cell infiltrates, but, for the first time, it was shown that there was immunoreaction for the glutamate receptor NMDAR1 in association with nerve structures in human patellar tendons. These findings altogether indicate that glutamate might be involved in painful Jumper's knee, and further emphasizes that there is no chemical inflammation (normal PGE2 levels) in this chronic condition. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
The relationship between graft tensioning and the anterior—posterior laxity in the anterior cruciate ligament reconstructed goat knee
Authors: Fleming Braden C. , Abate Joseph A. , Peura Glenn D. , Beynnon Bruce D.
Published: July 2002

The tension applied to the anterior cruciate ligament (ACL) graft at time of fixation is thought to influence graft healing, knee kinematics, and joint contact forces; however, the optimal tensioning procedure remains unclear. An animal model provides a means by which the effect of graft tensioning on healing can be studied. Prior to using the model, the relationship between graft tensioning and knee kinematics at time of surgery should be established. Our objective was to explore the relationship between graft tensioning and anterior—posterior (A—P) laxity of the reconstructed goat knee. Eight cadaver knees were tested. The A—P laxity values of the intact knee were measured with the knee at 30°, 60°, and 90° flexion. The ACL was then severed and the laxity measurements were repeated. The ACL was reconstructed using a bone‐patellar tendon—bone autograft. The laxity measurements were repeated for nine different tensioning conditions; three tension magnitudes (30, 60, and 90 N), each applied with the knee at three angles (30°, 60° and 90°). Both graft tension and the knee angle at which it was applied produced significant changes on A—P laxity values. An increase in tension reduced laxity values. A tension level of 60 N applied with the knee flexed to 30° was the best combination for restoring normal A—P laxity values at all knee angles tested. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
Glycosaminoglycans co‐administration enhance insulin‐like growth factor‐I neuroprotective and neuroregenerative activity in traumatic and genetic models of motor neuron disease: a review
Authors: Di Giulio Anna Maria , Germani Elena , Lesma Elena , Muller Eugenio , Gorio Alfredo
Published: July 2002

In this report it is shown how glycosaminoglycans and insulin‐like growth factor‐I (IGF‐I) promote muscle reinnervation and prevent motor neuron death in experimental models of motor neuron disease. Such effect appears to be mediated by insulin‐like growth factor‐1. The glycosaminoglycan moiety of proteoglycans is a constituent of the basal lamina active on nerve regeneration by means of the interaction with laminin and with several growth factors. We have previously shown that supplementation by means of subcutaneous injections of glycosaminoglycans affects neuronal degeneration and regeneration. In this study we report that following neonatal lesion of the rat sciatic nerve, glycosaminoglycan treatment promoted extensor digitorum longus muscle reinnervation with consequent improvement of muscle morphology. In saline‐treated rats, reinnervation was only partial and there was a marked muscle fibre atrophy, whereas, glycosaminoglycan treatment of lesioned rats increased IGF‐I mRNA and protein in the reinnervated muscle, and IGF‐I and insulin‐like growth factor binding protein‐3 plasma levels. Similarly, treatment of lesioned rats with IGF‐I promoted muscle reinnervation, and prevented muscle fibre atrophy, higher levels of IGF‐I in the reinnervated muscle, of IGF‐I, and insulin‐like growth factor binding proteins in plasma. In the wobbler mouse IGF‐I and glycosaminoglycans alone promote only a partial motor neuron survival and the preservation of forelimb function decays after 3 weeks of treatment. However when glycosaminoglycans and insulin‐like growth factor are administered together the motor neuron disease in the wobbler mouse is halted and there is no more loss of motor neurons.
Murine homologs of deltex define a novel gene family involved in vertebrate Notch signaling and neurogenesis
Authors: Kishi Noriyuki , Tang Zhenyu , Maeda Yusuke , Hirai Asami , Mo Rong , Ito Mikiko , Suzuki Satoshi , Nakao Keiko , Kinoshita Tsutomu , Kadesch Tom , Hui Chi‐chung , Artavanis‐Tsakonas Spyros , Okano Hideyuki , Matsuno Kenji
Published: July 2002

Notch signaling plays an important role in cell‐fate specification in multicellular organisms by regulating cell–cell communication. The Drosophila deltex gene encodes a modulator of the Notch pathway that has been shown to interact physically with the Ankyrin repeats of Notch. We isolated four distinct cDNAs corresponding to mouse homologs of deltex — mouse Deltex1 (MDTX1), mouse Deltex2 (MDTX2), mouse Deltex2ΔE (MDTX2ΔE), and mouse Deltex3 (MDTX3). Deduced amino acid sequences of these four cDNAs showed a high degree of similarity to Drosophila Deltex and its human homolog, DTX1 throughout their lengths, even though they possess distinct structural features. MDTX proteins formed homotypic and heterotypic multimers. We found that these genes were expressed in the central, peripheral nervous system and in the thymus, overlapping with those of mouse Notch1. In mammalian tissue culture cells, overexpression of any of the four mouse deltex homologs suppressed the transcriptional activity of E47, a basic helix‐loop‐helix (bHLH) protein, in a manner similar to suppression by an activated form of human Notch1 or human DTX1. In addition, overexpression of MDTX2 and MDTX2ΔE in C2C12 cells under differentiation‐inducing conditions suppressed the expression of myogenin, one of the myogenic transcriptional factors; this was also similar to a previously reported activity of constitutively activated Notch. Furthermore, misexpression of any of the MDTX genes in Xenopus embryos resulted in an expansion of the region expressing the neural cell adhesion molecule (N‐CAM) gene, a marker for the neuroepithelium. Collectively, our results suggest that these mouse deltex homologs are involved in vertebrate Notch signaling and regulation of neurogenesis.
Discharge properties of pigeon single auditory nerve fibers after recovery from severe acoustic trauma
Authors: Müller M. , Smolders J.W.Th , Ding‐Pfennigdorff D. , Klünke R.
Published: July 2002

The time course of recovery of compound action potential (CAP) thresholds was observed in individual adult pigeons after severe acoustic trauma. Each bird had electrodes implanted on the round window of both ears. One ear was exposed to a tone of 0.7 kHz at 136–142 dB SPL for 1 hr under general anesthesia. Recovery of CAP audiograms was monitored twice a week after trauma. Single unit recordings from auditory nerve fibers were made after 3 weeks and after 4 or more months of the exposure. The CAP was abolished immediately after overstimulation in all animals. Based on the temporal patters of functional recovery of the CAP three groups of animals were identified. The first group was characterized by fast functional recovery starting immediately after trauma followed by a return to pre‐exposure values within 3 weeks. In the second group, slow functional recovery of threshold started 1–2 weeks after trauma followed by a return to pre‐exposure values by 4–5 weeks. A mean residual hearing loss of 26.3 dB at 2 kHz remained. The third group consisted of animals that did not recover after trauma. Three weeks after the exposure, tuning curves of single auditory nerve fibers were very broad and sometimes irregular in shape. Their thresholds hovered around 120 dB SPL. Spontaneous firing rate and driven rate were much reduced. Four or more months after exposure, the thresholds and sharpness of tuning of many single units were almost completely recovered. Spontaneous firing rate and driven rate were comparable to those of control animals. In the slow recovery group neuronal tuning properties showed less recovery, especially at frequencies above the exposure frequency. Thresholds and sharpness of tuning were normal at frequencies below the exposure frequency, but were much poorer at frequencies above the exposure. Spontaneous firing rate was much reduced in fibers with high characteristic frequencies. In fast recovering animals, the papilla was repopulated with hair cells after 4 months. In slow recovering animals, short (abneural) hair cells were still missing over large parts of the papilla after 4 months of recovery. Residual short (abneural) hair cell loss was largest at two areas, one more basal and the other more apical to the characteristic place of the traumatizing frequency. The results show that, in adult birds, functional recovery from severe damage to both short (abneural) and tall (neural) hair cells occurs. However, the onset of recovery is delayed and the time course is slower than after destruction of short (abneural) hair cells alone. Also, recovery is incomplete, both functionally and morphologically. There is residual permanent hearing loss, and regeneration of short (abneural) hair cells is incomplete.
The preclinical pharmacologic profile of tiapride
Authors: Scatton B. , Cohen C. , Perrault G. , Oblin A. , Claustre Y. , Schoemaker H. , Sanger D.J. , Rouquier L. , Porsolt R.
Published: July 2002

Tiapride is a benzamide derivative that has been used successfully in the clinic for a number of years for the treatment of agitation and aggressiveness in elderly patients. Like many substituted benzamides, tiapride specifically blocks dopamine receptors in the brain. It has affinity for dopamine D2 (IC50 = 110–320 nM) and D3 (IC50 = 180 nM) receptors in vitro but lacks affinity for dopamine D1 and D4 receptors and for non-dopaminergic receptors including H1, α1, α2-adrenergic and serotonergic receptors. Tiapride also shows dose-related inhibition of [3H]-raclopride binding in limbic areas and in the striatum of the rat in vivo (ED50 ∼ 20 mg/kg, ip). In microdialysis experiments, tiapride (over the range 10–30 mg/kg, ip) increased extracellular levels of dopamine in the nucleus accumbens and striatum, a reflection of its blockade of postsynaptic dopamine receptors in these brain areas.

In behavioral experiments in rats, lower doses of tiapride (ED50 = 10 mg/kg, ip) antagonised dopamine agonist-induced hyperactivity while higher doses (ED50 = 60 mg/kg, ip) were required to block stereotyped movements.

In addition, doses of tiapride up to 200 mg/kg, ip failed to induce catalepsy, an effect observed with many other drugs which block dopamine receptors. In tests of conditioned behavior in rats, tiapride was found to give rise to an interoceptive stimulus associated with dopamine receptor blockade at doses (ED50 = 2.2 mg/kg, ip) much lower than those producing motor disturbances or sedation (ED50 = 40 mg/kg, ip), in striking contrast to a range of conventional or atypical neuroleptics that produced interoceptive stimulus and sedation at similar doses. Furthermore, the acquisition by rats of a place-learning task in a water maze was not affected by tiapride (over the range 3–30 mg/kg, ip), whereas haloperidol (MED = 0.25 mg/kg, ip) and risperidone (MED = 0.03 mg/kg, ip) impaired performance.

The preclinical pharmacologic and behavioral profile of tiapride suggests that its clinical activity may be due to a selective blockade of dopamine D2 and D3 receptors in limbic brain regions. The results are also consistent with a lack of motor or cognitive side effects.
Poland ten years after: the church
Authors: Korbonski Andrzej
Published: July 2002

Ten years after the collapse of communist rule, church-state relations in Poland present a mixed picture. On the one hand, the Roman Catholic church continues to enjoy a privileged position in the country and has achieved most of its cherished goals. On the other hand, its very success carried with it seeds of its future decline. This was particularly true in several areas where the church's aggressive and arrogant behavior has proved counter productive: religious education, anti-abortion legislation, Christian values in mass media, antisemitism, murky church finances, the concordat with the Holy See, and the debate on the new constitution. As a result, there has been a steady decline in popular support for the church which itself has developed some serious rifts in its supposedly united posture. It may be hypothesized that the power and influence of the church actually peaked in the early 1990s and that, having absorbed some of the lessons from its decline, its future policies may well be less triumphalist and controversial, and more accommodating.
Financial services and the African-American market
Authors: Plath D. Anthony , Stevenson Thomas H.
Published: July 2002

African-American consumers differ markedly from their Caucasian counterparts in terms of financial product preferences, product research, and investment asset portfolio composition. This study examines some of the principal differences between African-American and Caucasian house- holds in evaluating and purchasing investment assets and explores differences in asset holdings between the two racial groups. This information can help financial planners seeking to market to the African-American community better understand this community, tailor investment information for the unique needs of this community, and render more effective service to individuals and families that comprise this attractive and growing market segment. © 2001 Elsevier Science Inc. All rights reserved.
More ‘malignant’ than cancer? Five‐year survival following a first admission for heart failure
Authors: Stewart Simon , MacIntyre Kate , Hole David J. , Capewell Simon , McMurray John J.V.
Published: July 2002

Background:

The prognostic impact of heart failure relative to that of ‘high‐profile’ disease states such as cancer, within the whole population, is unknown.

Methods:

All patients with a first admission to any Scottish hospital in 1991 for heart failure, myocardial infarction or the four most common types of cancer specific to men and women were identified. Five‐year survival rates and associated loss of expected life‐years were then compared.

Results:

In 1991, 16224 men had an initial hospitalisation for heart failure (n ‐ 3241), myocardial infarction (n ‐ 6932) or cancer of the lung, large bowel, prostate or bladder (n ‐ 6051). Similarly, 14842 women were admitted for heart failure (n ‐ 3606), myocardial infarction (n ‐ 4916), or cancer of the breast, lung, large bowel or ovary (n ‐ 6320). With the exception of lung cancer, heart failure was associated with the poorest 5‐year survival rate (approximately 25% for both sexes). On an adjusted basis, heart failure was associated with worse long‐term survival than bowel cancer in men (adjusted odds ratio, 0.89; 95% CI, 0.82–0.97; P < 0.01) and breast cancer in women (odds ratio, 0.59; 95% CI, 0.55–0.64; P < 0.001). The overall population rate of expected life‐years lost due to heart failure in men was 6.7 years/1000 and for women 5.1 years/1000.

Conclusion:

With the notable exception of lung cancer, heart failure is as ‘malignant’ as many common types of cancer and is associated with a comparable number of expected life‐years lost.
Enhanced endothelin‐1‐induced contractions in mesenteric arteries from rats with congestive heart failure: role of ETB receptors
Authors: Bergdahl Anders , Valdemarsson Stig , Adner Mikael , Sun Xiang‐Ying , Hedner Tomas , Edvinsson Lars
Published: July 2002

Studies of congestive heart failure (CHF) in man and in experimental CHF have demonstrated elevated circulating levels of endothelin (ET). In order to examine whether there are concomitant ET receptor alterations, the vasomotor effects of endothelin‐1 (ET‐1) and sarafotoxin 6c (S6c) were examined in endothelium‐intact and ‐denuded isolated mesenteric arteries from rats with CHF. CHF was induced by ligation of the left anterior descending coronary artery. Vasomotor responses were studied using small mesenteric arteries (approx. 250 μm in diameter, determined after normalisation). The antagonists IRL2500 and FR139317 were used in order to characterise the ET‐1‐induced response. In mesenteric arteries with intact endothelium, ET‐1‐induced contractions were more potent in CHF as compared to sham (pEC50 9.6 ± 0.2 and 9.1 ± 0.1, respectively, P < 0.01). In endothelium‐denuded arteries, there was no difference in potency of ET‐1 between CHF and sham arteries, or in maximum contraction. In the presence of IRL2500, a selective ETB‐receptor antagonist, ET‐1 was more potent in endothelium‐denuded arteries of CHF rats, while this difference was not seen in sham arteries. S6c had no consistent contractile or dilatory effect in CHF and sham rats. The results indicate that the enhanced contractile effects of ET‐1 noted in CHF might be due to an attenuated endothelial function and that inhibition of smooth muscle cell ETB receptors increase the effects of contractile ETA receptors in CHF rats.
Evaluation of impaired left ventricular ejection fraction and increased dimensions by multiple neurohumoral plasma concentrations
Authors: Groenning Bjoern A. , Nilsson Jens C. , Sondergaard Lars , Kjaer Andreas , Larsson Henrik B.W. , Hildebrandt Per R.
Published: July 2002

Background

A range of neurohumoral substances have been suggested as diagnostic markers in heart failure. It is, however, undetermined which marker has the greatest diagnostic potential, and whether additional information is gained by a comprehensive neurohumoral evaluation.

Aims

The purpose of the study was to compare the value of epinephrine, norepinephrine, renin activity, aldosterone (ALDO), atrial (ANP) and brain (BNP) natriuretic peptides, arginine‐vasopressin and endothelin (ENDO) as markers for left ventricular (LV) dimensions and ejection fraction (LVEF) in patients with systolic heart failure.

Methods

Forty‐eight patients with symptomatic heart failure were examined with blood samples and magnetic resonance imaging along with 20 age and gender‐matched normal controls.

Results

In multiple regression analyses, BNP was the strongest independent marker for LV end‐diastolic (r‐0.71, P<0.0001), and end‐systolic (r‐0.75, P<0.0001) volumes, myocardial mass (r‐0.69, P<0.0001), and LVEF (r‐−0.78, P<0.0001). ANP was a supplementary independent marker for LV end‐diastolic (r‐0.76, P<0.0001) and end‐systolic (r‐0.78, P<0.0001) (ANP and BNP combined) volumes, ENDO for myocardial mass [r‐0.71, P<0.0001 (ENDO/BNP)], and ALDO for LVEF [r‐−0.81, P<0.0001 (ALDO/BNP)].

Conclusion

BNP is the strongest marker for LV dimensions and LVEF in patients with systolic heart failure. However, a comprehensive neurohumoral evaluation may add some information to the diagnosis.
Preventing Perinatal Transmission of HIV: An Evidence‐Based Update For Midwives
Authors: Patchen Loral , Beal Margaret W.
Published: July 2002

This article presents an update on human immunodeficiency virus care in the United States, with an emphasis on care during pregnancy and strategies to prevent perinatal transmission. Common drug regimens are reviewed. Obstetric factors related to transmission, such as mode of delivery, also are discussed. Guidelines for collaboration between midwives and human immunodeficiency virus specialists are outlined.
A Red Light‐Triggered Drug Release System Based on One‐Photon Upconversion‐Like Photolysis
Authors: Lv Wen , Long Kaiqi , Yang Yang , Chen Sijie , Zhan Changyou , Wang Weiping
Published: September 2020

Photoresponsive drug release systems can enhance drug accumulation at the sites where light is applied. Nowadays, the photocleavable groups used in the systems usually require ultraviolet or blue light irradiation, which limits tissue penetration depth and is harmful to normal cells and living bodies. A one‐photon upconversion‐like photolysis strategy, which can cleave green light‐activatable prodrugs with red light at the presence of a red light‐excitable photosensitizer in organic solvents, is developed. However, both the prodrug and photosensitizer are hydrophobic and their energy transfer process is sensitive to oxygen molecules. Here, a simple strategy to address these problems by loading the two components in biocompatible and biodegradable polymeric micelles, is presented. The developed low‐irradiance red light‐triggered drug release system has a size around 40 nm and exhibits good stability in aqueous solutions. The micellar encapsulation protects the photolysis reaction from oxygen quenching in normoxia aqueous solutions. The therapeutic effect of the system enhanced by the redlight irradiation is demonstrated through in vitro and in vivo studies, indicating promising potential in cancer therapy. The study provides the first example and also an important reference for applying one‐photon upconversion‐like photolysis in biomedical applications.
Memristors Based on 2D Materials as an Artificial Synapse for Neuromorphic Electronics
Authors: Huh Woong , Lee Donghun , Lee Chul‐Ho
Published: September 2020

The memristor, a composite word of memory and resistor, has become one of the most important electronic components for brain‐inspired neuromorphic computing in recent years. This device has the ability to control resistance with multiple states by memorizing the history of previous electrical inputs, enabling it to mimic a biological synapse in the neural network of the human brain. Among many candidates for memristive materials, including metal oxides, organic materials, and low‐dimensional nanomaterials, 2D layered materials have been widely investigated owing to their outstanding physical properties and electrical tunability, low‐power‐switching capability, and hetero‐integration compatibility. Hence, a large number of experimental demonstrations on 2D material‐based memristors have been reported showing their unique memristive characteristics and novel synaptic functionalities, distinct from traditional bulk‐material‐based systems. Herein, an overview of the latest advances in the structures, mechanisms, and memristive characteristics of 2D material‐based memristors is presented. Additionally, novel strategies to modulate and enhance the synaptic functionalities of 2D‐memristor‐based artificial synapses are summarized. Finally, as a foreseeing perspective, the potentials and challenges of these emerging materials for future neuromorphic electronics are also discussed.
Surpassing Cu–Ta Miscibility Barriers Using a High‐Current Pulsed Arc
Authors: Mendoza‐Pérez Rafael , Bahrami Amin , Calderón‐Olvera Roxana M. , Romero‐Ibarra Josué E. , Álvarez‐Zauco Edgar , Huerta Lázaro , Muhl Stephen
Published: September 2020

The improvement of many applications in the fields of catalysis, surface and coatings technology, biomedicine, and fuel cells depends on the advances in nanoalloy research. Here, a structural and thermal study of nanostructures of Cu–Ta particles produced using a high‐current pulsed arc (HCPA) is presented. Structural analysis performed utilizing electron microscopy and X‐ray spectroscopy shows the formation of distinctive single crystals with grain sizes larger than 100 nm. Notably, these grains exhibit evidence of a variation of the characteristic immiscibility of Cu and Ta, as found in the bulk scale. The nonequilibrium HCPA method appears to offer a way to surpass miscibility barriers in bimetallic alloys. This technique also allows the synthesis of oxygen‐free powders in sufficient quantities to perform a variety of characterization measurements. The detailed Cu–Ta alloy crystals and oxidation temperature in a high purity oxygen atmosphere and the stability at high temperatures in argon are analyzed.
Determination of Fermi Level Position at the Graphene/GaN Interface Using Electromodulation Spectroscopy
Authors: Herman Artur P. , Janicki Lukasz , Stokowski Hubert S. , Rudzinski Mariusz , Rozbiegala Ewelina , Sobanska Marta , Zytkiewicz Zbigniew R. , Kudrawiec Robert
Published: September 2020

Graphene together with other 2D nanomaterials, due to their exceptional physiochemical properties, are often considered as excellent building blocks for fabrication of more complex heterostructures. Despite the processing‐related issues the question of high importance for engineering of such systems is to fully understand the electronic phenomena at the interfaces. Electromodulation spectroscopy is extensively used in optical studies of semiconductors. Here, it is demonstrated that this nondestructive method may also be used to study the built‐in electric fields in a complex graphene–semiconductor heterostructures, making it possible to precisely determine the potential barrier height at the interface and therefore to assess the electrical character of the junction. The study is focused on an especially interesting graphene–semiconductor pair, i.e., graphene/GaN nevertheless it can be applied to a broad diversity of heterostructures, particularly those consisting of van der Waals crystals. The results reveal that after deposition of a graphene the Fermi level is unpinned from native GaN surface states and, instead, located at a graphene/GaN interface characteristic energy.
Zero‐Dimensional MXene‐Based Optical Devices for Ultrafast and Ultranarrow Photonics Applications
Authors: Xu Ning , Li Hongbo , Gan Yiyu , Chen Hualong , Li Wenjia , Zhang Feng , Jiang Xiantao , Shi Yihuan , Liu Jiefeng , Wen Qiao , Zhang Han
Published: September 2020

In recent years, MXene has become a hotspot because of its good conductivity, strong broadband absorption, and tunable band gap. In this contribution, 0D MXene Ti3C2Tx quantum dots are synthesized by a liquid exfoliation method and a wideband nonlinear optical response from 800 to 1550 nm is studied, which have a larger nonlinear absorption coefficient β of –(11.24 ± 0.14) × 10–2 cm GW–1. The carrier dynamic processes of 0D MXene are explored with ultrahigh time resolution nondegenerate transient absorption (TA) spectroscopy, which indicates that the TA signal reaches its maximum in 1.28 ps. Furthermore, 0D MXene is used to generate ultrashort pulses in erbium or ytterbium‐doped fiber laser cavity. High signal‐to‐noise (72 dB) femtosecond lasers with pulse durations as short as 170 fs with spectrum bandwidth of 14.8 nm are obtained. Finally, an ultranarrow fiber laser based on 0D MXene is also investigated and has a full width at half maximum of only 5 kHz, and the power fluctuation is less than 0.75% of the average power. The experimental works prove that 0D MXene is an excellent SA and has a promising application in ultrafast and ultranarrow photonics.
Microclusters of Kinked Silicon Nanowires Synthesized by a Recyclable Iodide Process for High‐Performance Lithium‐Ion Battery Anodes
Authors: Jeong You Kyeong , Huang William , Vilá Rafael A. , Huang Wenxiao , Wang Jiangyan , Kim Sang Cheol , Kim Yong Seok , Zhao Jie , Cui Yi
Published: September 2020

Silicon shows great promise as a high‐capacity anode material for lithium‐ion batteries. Nanostructuring silicon minimizes the impact of fracturing during charging and discharging. However, synthesizing nanostructured silicon typically requires complicated procedures with high manufacturing costs. Additionally, these complicated procedures typically have poor secondary particle formation, a requirement to achieve a high tap density. Here, a cost‐effective synthesis procedure which generates nearly ideal secondary particle clusters of nanostructured silicon is developed. The cost‐effectiveness is a result of the in operando generation of silicon iodide from iodine gas and low‐grade silicon microparticle. Decomposition of silicon iodide into crystalline silicon and iodine gas enables recycling of the iodine gas, allowing for near full reutilization of iodine in the following cycles. The optimal nanostructures and microstructures of silicon synthesized by the recyclable iodide decomposition reaction enables 83.6% capacity retention over 1000 cycles. The good performance is a result of well‐maintained morphology during cycling, enabling reutilization of the solid electrolyte interphase.
Ultrahigh‐Rate Supercapacitor Based on Carbon Nano‐Onion/Graphene Hybrid Structure toward Compact Alternating Current Filter
Authors: Zhang Chenguang , Du Haozhe , Ma Ke , Yuan Zhihao
Published: September 2020

Traditional filtering capacitors suffer from low volumetric energy density (Ev), which hinders their integration in miniaturized electronics and their high‐frequency response ability to alternating current (AC). Here, a supercapacitor based on a carbon nano‐onion (CNO)‐graphene hybrid structure concurrently possessing high Ev and ultrahigh rate capability is reported for AC filtering. The hybrid structure is synthesized on etched nickel foil using preformed monodispersed nanocrystals through a chemical vapor deposition method. The supercapacitor device shows capacitive behavior independent of voltage scan rate up to 5000 V s−1 in both aqueous and organic electrolytes, which represents a record high among the reported filtering capacitors to date. It also exhibits a high Ev of 14.9 F V2 cm−3 at 120 Hz and 28.8 mWh cm−3 at a current density of 0.25 mA cm−2. Moreover, the supercapacitor is capable of filtering AC with different waveforms at high frequencies into direct current. The hybrid structure holds promise for applications in compact filtering units. The ultrafast ion transportation performance is enabled by the highly positive surface curvature of CNOs, hierarchical interconnection of CNO particles, and the covalent interfacial bonding between CNOs and graphene.
Conversion of Methane into Liquid Fuels—Bridging Thermal Catalysis with Electrocatalysis
Authors: Yuan Shuai , Li Yanding , Peng Jiayu , Questell‐Santiago Ydna M. , Akkiraju Karthik , Giordano Livia , Zheng Daniel J. , Bagi Sujay , Román‐Leshkov Yuriy , Shao‐Horn Yang
Published: September 2020

The direct partial oxidation of methane to methanol promises an energy‐efficient and environmental‐friendly utilization of natural gas. Unfortunately, current technologies confront a grand challenge in catalysis, particularly in the context of distributed sources. Research has been focused on the design of homogenous and heterogenous catalysts to improve the activation of methane under thermal and electrochemical conditions. However, the intrinsic relationship between thermal and electrochemical systems has not been exploited yet. This review intends to bridge the studies of thermal and electrochemical catalysts, in both homogenous and heterogenous systems, for methane activation from a mechanistic point of view. It is expected to provide a framework to rationalize the design of electrocatalysts beyond the state of art. First, methane activation systems reported previously are reviewed and classified into two basic mechanisms: dehydrogenation and deprotonation. Based on the mechanism types, activity and selectivity descriptors are defined to understand the performance of current catalysts and guide the design of future catalysts. Moreover, methods to enhance the activity and selectivity are discussed to emphasize the unique advantage of electrocatalysis in overcoming the limitations of traditional thermal catalysis. Finally, immense opportunities and challenges for catalyst design are discussed by unifying thermal and electrochemical catalysis.
Evolutionary trade‐offs in the chemical defense of floral and fruit tissues across genus Cornus
Authors: De La Pascua Danielle R. , Smith‐Winterscheidt Corrinne , Dowell Jordan A. , Goolsby Eric W. , Mason Chase M.
Published: September 2020

Premise

Defense investment in plant reproductive structures is relatively understudied compared to the defense of vegetative organs. Here the evolution of chemical defenses in reproductive structures is examined in light of the optimal defense, apparency, and resource availability hypotheses within the genus Cornus using a phylogenetic comparative approach in relation to phenology and native habitat environmental data.

Methods

Individuals representing 25 Cornus species were tracked for reproductive phenology over a full growing season at the Arnold Arboretum of Harvard University. Floral, fruit, and leaf tissue was sampled to quantify defensive chemistry as well as fruit nutritional traits relevant to bird dispersal. Native habitat environmental characteristics were estimated using locality data from digitized herbarium records coupled with global soil and climate data sets.

Results

The evolution of later flowering was correlated with increased floral tannins, and the evolution of later fruiting was correlated with increased total phenolics. Leaves were found to contain the highest tannin activity, while inflorescences contained the highest total flavonoids. Multiple aspects of fruit defensive chemistry were correlated with fruit nutritional traits. Floral and fruit defensive chemistry were evolutionarily correlated with aspects of native habitat temperature, precipitation, and soil characteristics.

Conclusions

Results provide tentative support for the apparency hypothesis with respect to both flower and fruit phenology, while relative concentrations of secondary metabolites across organs provide mixed support for the optimal defense hypothesis. The evolution of reproductive defense with native habitat provides, at best, mixed support for the resource availability hypothesis.