bluuebunny/crossref_metadata_2025_split huggingface dataset:
EXTRACTION OF MINUTE GAS BUBBLES FROM LIQUIDS FLOWING IN A SIMULATED CARDIOPULMONARY BYPASS SYSTEM BY A VENTURI-ASPIRATOR UNIT
Authors: YANG WEN-JEI , EID AMR , ECHIGO R. 
Published: January 2003

An experimental study is performed to extract minute gas bubbles from liquids flowing in a simulated cardiopulmonary bypass system using a Venturi-aspirator unit. In other words, oxygen bubbles in oxygenated blood are simulated by air bubbles in water with AP30 (about same viscosity as whole blood). This study is intended to determine the feasibility of using a Venturi aspirator unit to extract minute gas bubbles from a simulated cardiopulmonary bypass system. Testing of the Venturi-type bubble extraction is carried out using three different test sections. Two Venturis are used, and a straight tube configuration is used as a control. The two Venturis are similar, with the exception that one has a longer inlet cone which causes the entering liquid to accelerate at a slower rate. Results are obtained for effectiveness of the aspirator unit as functions of total flow rate, extraction suction, suction pressure difference, and hydraulic head. It is concluded from the study that:(i) The effectiveness of the Venturis is typically between 90 and 100 percent. It increases with an increase in suction or suction pressure difference but decreases with an increase in total flow rate.(ii) The Venturi is most suitable for extraction of minute gas bubbles, especially for use with AP30 (whole blood), which yields substantially higher effectiveness than water.(iii) It is anticipated that a Venturi-aspirator unit can be superior to other bubble separation device as the cardiopulmonary bypass system for applications in extra corporeal blood oxygenation.
Marijuana Use and Prior Injury among Injured Problem Drinkers
Authors: Woolard Robert , Nirenberg Ted D. , Becker Bruce , Longabaugh Richard , Minugh P. Allison , Gogineni Aruna , Carty Kathleen , Clifford Patrick R. 
Published: January 2003

Abstract Objectives: The purpose of this paper is to better understand marijuana use among injured problem drinkers in the emergency department (ED). The specific objectives are: 1) to assess the prevalence of marijuana use; 2) to identify factors associated with marijuana use; 3) to determine whether prior injury is associated with marijuana use; and 4) to determine whether marijuana‐using problem drinkers want to change behaviors. Methods: The authors conducted a post‐hoc analysis on data obtained prospectively. Subjects had injury and problem drinking: either measurable alcohol level (blood alcohol concentration, BAC), report of drinking, or an Alcohol Use Disorders Identification Test (AUDIT) score of ≥8. The study was conducted on weekend nights; 3,776 injured ED patients were screened, 383 refused, 578 were enrolled, and 433 had complete data. Results: Of the 433 subjects, 48.3% reported using marijuana in the three months prior. Marijuana‐using problem drinkers had more hazardous drinking, higher AUDIT scores (14.0 vs. 11.4, p < 0.001), and higher risk‐taking scores (12.4 vs. 10.1, p < 0.001). More used other drugs (69.7% vs. 30.3%, p < 0.001). In regression analyses, marijuana use remained an independent predictor of prior injury (OR = 2.16, 95% CI = 1.25 to 3.75), particularly prior alcohol‐related (OR = 2.26, 95% CI = 1.45 to 3.53) and motor‐vehicle‐related (OR = 1.69, 95% CI = 1.03 to 2.79) injury. Readiness‐to‐change scores were similar (4.14 vs. 4.22, p = 0.21) between users and nonusers. Conclusions: Marijuana use among injured problem drinkers is prevalent. Their risk of prior injury is increased. Counseling for alcohol and injury should address marijuana use.
Interactions Between Suspended Nanowires and Patterned Surfaces
Authors: Martin B.R. , Angelo S.K.St. , Mallouk T.E. 
Published: December 2002

AbstractGold nanowires, 350 nm in diameter and 3–6 μm in length, were derivatized by using positively and negatively charged self‐assembled monolayers. The interactions between these particles and surfaces were investigated as a function of their surface chemistry and topography. Electrostatically repulsive sulfonate–sulfonate interactions resulted in mobile particles on the surface, whereas electrostatically attractive interactions between polyamines and sulfonates immobilized the particles. Patterned surfaces were selectively derivatized with particles using these attractive and repulsive interactions. By lithographically defining surface wells that were commensurate with the length of the nanowires, nanowire bundles were assembled in the wells.
Chemistry of Phosphine–Borane Adducts at Platinum Centers: Synthesis and Reactivity of PtII Complexes with Phosphinoborane Ligands
Authors: Jaska Cory A. , Dorn Hendrik , Lough Alan J. , Manners Ian 
Published: December 2002

AbstractReaction of [Pt(PEt3)3] with the primary and secondary phosphine–borane adducts PhRPH⋅BH3 (R=H, Ph) resulted in oxidative addition of a PH bond at the Pt0 center to afford the complexes trans‐[PtH(PPhR⋅BH3)(PEt3)2] (1: R=H; 2: R=Ph). The products 1 and 2 were characterized by 1H, 11B, 13C, 31P, and 195Pt NMR spectroscopy, and the molecular structures were verified by X‐ray crystallography. In both cases, a trans arrangement of the hydride ligand with respect to the phosphidoborane ligand was observed. When 2 was treated with PhPH2⋅BH3, a novel phosphidoborane ligand‐exchange reaction occurred which yielded 1 and Ph2PH⋅BH3. Treatment of 2 with one equivalent of depe (depe=1,2‐bis(diethylphosphino)ethane) resulted in the formation of the complex cis‐[PtH(PPh2⋅BH3)(depe)] (3), in which the hydride ligand and the phosphidoborane ligand are in a cis arrangement. Treatment of 3 with PhPH2⋅BH3 was found to result in an exchange of the phosphidoborane ligands to give the complex cis‐[PtH(PPhH⋅BH3)(depe)] (4) and Ph2PH⋅BH3. Complex 4 was found to undergo further reaction in the presence of PhPH2⋅BH3 to give meso‐cis‐[Pt(PPhH⋅BH3)2(depe)] (5) and rac‐cis‐[Pt(PPhH⋅BH3)2(depe)] (6).
A Family of Low‐Molecular‐Weight Hydrogelators Based on L‐Lysine Derivatives with a Positively Charged Terminal Group
Authors: Suzuki Masahiro , Yumoto Mariko , Kimura Mutsumi , Shirai Hirofusa , Hanabusa Kenji 
Published: December 2002

AbstractA family of L‐lysine‐based low‐molecular‐weight compounds with various positively charged terminals (pyridinium and imidazolium derivatives) was synthesized and its gelation behavior in water was investigated. Most of the compounds can be very easily synthesized in high yields (total yields >90 %), and they function as excellent hydrogelators that form hydrogels below 1 wt %; particularly, Nε‐lauroyl‐Nα‐[11‐(4‐tert‐butylpyridinium)undecanoyl]‐L‐lysine ethyl ester (2 c) and Nε‐lauroyl‐Nα‐[11‐(4‐phenylpyridinium)undecanoyl]‐L‐lysine ethyl ester (2 d), which are able to gel water at concentration of only 0.2 wt %. This corresponds to a gelator molecule that entraps more than 20 000 water molecules. All hydrogels are very stable and maintain the gel state for at least 9 months. TEM observations demonstrated that these hydrogelators self‐assemble into a nanoscaled fibrous structure; a three‐dimensional network is then formed by the entanglement of the nanofibers. An FTIR study in [D6]DMSO/D2O and in CHCl3 revealed the existence of intermolecular hydrogen bonding between the amide groups. This was further supported by a 1H NMR study in [D6]DMSO/H2O. A luminescence study, in which ANS (1‐anilino‐8‐naphtharenesulfonic acid) was used as a probe, indicated that the hydrogelators self‐assemble into nanostructures possessing hydrophobic pockets at a very low concentration. Consequently, it was found that the driving forces for self‐assembly into a nanofiber are hydrogel bonding and hydrophobic interactions.
Convenient Syntheses of Fluorous Aryl Iodides and Hypervalent Iodine Compounds: ArI(L)n Reagents That Are Recoverable by Simple Liquid/Liquid Biphase Workups, and Applications in Oxidations of Hydroquinones
Authors: Rocaboy Christian , Gladysz John A. 
Published: December 2002

AbstractIodinations of the ortho, meta, and para fluorous arenes (Rf8CH2CH2CH2)2C6H4 (Rf8=(CF2)7CF3) with I2/H5IO6 in AcOH/H2SO4/H2O give 3,4‐(Rf8CH2CH2CH2)2C6H3I (5) and the analogous 2,4‐ (6) and 2,5‐ (7) isomers, respectively. Spectroscopic yields are >90 %, but 5 and 7 must be separated by chromatography from by‐products (yields isolated: 70 %, 97 %, 61 %). Reaction of 1,3,5‐(Rf8CH2CH2CH2)3C6H3 with PhI(OAc)2/I2 gives 2,4,6‐(Rf8CH2CH2CH2)3C6H2I (8) on multigram scales in 97 % yield. The CF3C6F11/toluene partition coefficients of 5–8 (24 °C: 69.5:30.5 (5), 74.7:25.3 (6), 73.9:26.1 (7), 98.0:2.0 (8)) are lower than those of the precursors, but CF3C6F11/MeOH gives higher values (97.0:3.0 (5), 98.6:1.4 (6), 98.0:2.0 (7), >99.3:<0.3 (8)). Reactions of 5–8 with excess NaBO3 in AcOH yield the corresponding ArI(OAc)2 species 9–12 (9, 85 % as a 90:10 9/5 mixture; 10, 97 %; 11, 95 %; 12, 93 % as a 95:5 12/8 mixture). These rapidly oxidize 1,4‐hydroquinones in MeOH. Subsequent additions of CF3C6F11 give liquid biphase systems. Solvent removal from the CF3C6F11 phases gives 5–8 in >99–98 % yields, and solvent removal from the MeOH phases gives the quinone products, normally in >99–95 % yields. The recovered compounds 5–8 are easily reoxidized to 9–12 and used again.
Cover Picture: ChemPhysChem 1/2003
Authors: Petry Renate , Schmitt Michael , Popp Jürgen 
Published: December 2002

AbstractThe cover picture shows a picture of a Mentha × piperita plant, which has a high pharmaceutical relevance. Raman spectra of extremely high spatial resolution have been recorded of this plant by applying etched and silver‐coated glass fiber tips; a method which has been developed in our group within the scope of a BMBF project FKZ 13N7511 located in the framework of Laser‐Biodynamik. On the right, a picture of such a glass fiber tip illuminated by the Raman laser is shown. The fiber tip is brought extremely close to the sample area to be investigated. The picture also shows the Raman spectrum obtained by applying this fiber‐tip technique. This method allows the recording of Raman spectra of biologically relevant samples with an extremely high spatial resolution (200 nm).
Nitric oxide mediates metabolism as well as respiratory and cardiac responses to hypoxia in the snail lymnaea stagnalis
Authors: Taylor Barbara E. , Harris Michael B. , Burk Michele , Smyth Kim , Lukowiak Ken , Remmers John E. 
Published: December 2002

AbstractLymnaea stagnalis were exposed to hypoxic and chemical challenges while ventilation, heart rate and metabolism were monitored. Hypoxia increased ventilatory behavior, but this response was eliminated by immersion in 0.75 mM nitric oxide synthase (NOS) inhibitor, 7‐nitroindazole (7 NI). 7 NI also suppressed ventilatory behavior under normoxia. 10.0 mM L‐arginine (ARG, the NOS substrate) increased ventilatory behavior under normoxia, but dampened the hypoxic response. The heart‐rate response to NOS inhibition exhibited dose‐dependent contradictory characteristics. Under both normoxia and hypoxia 0.25 mM 7 NI increased heart rate, while 0.75 mM 7 NI suppressed it. The effect of 0.50 mM 7 NI depended on whether normoxia or hypoxia was coincident; under normoxia 0.50 mM 7 NI increased heart rate, while under hypoxia this concentration suppressed heart rate. Exposure to ARG did not elicit dose‐dependent contradictory responses. Heart rate increased when treated with 10.0 mM ARG under normoxia and hypoxia, while 1.0 mM ARG increased heart rate only under hypoxia. Metabolic responses to NOS inhibition also exhibited dose‐dependent contradictory changes. V·O2 decreased over 60% in response to 0.75 mM 7 NI, and baseline V·O2 was restored when exposure ceased. In contrast, 0.25 mM 7 NI increased V·O2 10%, and the increase continued after exposure ceased. 0.50 mM 7 NI decreased V·O2 40%, but V·O2 increased when exposure ceased. ARG had only the effect of increasing V·O2, and only at 10.0 mM concentration. Based on these results and on NO's known role as a neuromodulator, we conclude that the cardio‐respiratory responses to hypoxia are, in part, mediated by NO. J. Exp. Zool. 295A:37–46, 2003. © 2003, Wiley‐Liss, Inc.
“Some like it shallower” – p‐type doping in SiC
Authors: Deák Peter , Aradi Bálint , Gali Adam , Gerstmann Uwe 
Published: December 2002

AbstractThe usual p‐type dopants of SiC, B, and Al, do not produce really shallow levels. In fact, boron can give rise to a secondary very deep acceptor level as well. The picture is complicated by hydrogen which is readily incorporated during in‐growth doping into p‐type material and can passivate both dopants but to a different degree. First principle calculations are reported regarding the interaction of hydrogen with B and Al in SiC. The results explain why hydrogen is incorporated in much higher amounts into B‐doped than into Al‐doped samples, and also reveal the influences of hydrogen on boron to produce the shallower acceptor. It will be shown that hydrogen incorporation during growth does not influence Al. Finally an Al–N–Al complex is proposed as a shallower acceptor in SiC.
Residual donors in wurtzite GaN homoepitaxial layers and heterostructures
Authors: Neu G. , Teisseire‐Doninelli M. , Morhain C. , Semond F. , Grandjean N. , Beaumont B. , Frayssinet E. , Knap W. , Witowski A. M. , Sadowski M. L. , Leszczynski M. , Prystawko P. 
Published: December 2002

AbstractShallow donors in GaN epilayers grown by metalorganic chemical vapour deposition (MOCVD) and by molecular beam epitaxy (MBE) on sapphire, SiC and GaN substrates have been studied by selectively excited photoluminescence (SPL) and far‐infrared (FIR) absorption. The spectroscopic studies of neutral donor bound excitons allow us to determine the D0X rotational excited state spectra in a large domain of tensile and compressive strain fields depending on the substrates used for the growth. The energy transitions between the ground state and the n = 2 states of residual donors are determined from the spectra of the two‐electron replica of D0X lines in accordance with resonant electronic Raman scattering results. The comparison between FIR results and the two‐electron spectroscopy shows, that silicon is the main residual donor (Ed = 30.4 meV in strain‐free samples) in both MOVPE and MBE layers. A second unknown donor (Ed = 31.8 meV) is frequently found in GaN/SiC grown by MOCVD. A third deeper level (Ed = 33.1 meV) is rarely detected by two‐electron spectroscopy but could be associated with a weak neutral‐donor bound exciton shifted down by 0.9 meV from the main SiGa related D0X line in MBE homoepitaxial layers.
Dynamics of trapping on donors and relaxation of the B‐exciton in GaN
Authors: Korona K. P. , Wysmołek A. , Stępniewski R. , Potemski M. , Kuhl J. , Baranowski J. M. , Martinez G. , Grzegory I. , Porowski S. 
Published: December 2002

AbstractThere are three exciton branches in wurzite‐GaN: A, B and C. Here, time‐resolved photoluminescence and magneto‐optic spectroscopy of the B‐exciton are presented, both free (FXB) and bound to donor (D0XB) in homoepitaxial GaN. The free B‐exciton has an energy of about 3.483 eV and a very short lifetime of about 20 ps. The B‐exciton bound to donor (D0XB) has an energy of 3.475 eV and a lifetime longer than the free excitons but shorter than the lifetime of the A‐exciton bound to donor. It is shown that a simple model based on an invariant expression describes properly the behavior of D0XA and D0XB in a magnetic field. Results of resonance excitation experiments suggest that in many cases the process of binding a free exciton to a donor conserves the exciton type and that the relaxation of B‐ to A‐exciton takes place later. Moreover, thermal excitation of D0XA to D0XB has been observed.
Escherichia coli
and
Salmonella
2000: the View From Here
Authors: Schaechter Moselio ,   The View From Here Group
Published: January 2003

SUMMARY
Five years after the publication of the second edition of the reference book Escherichia coli and Salmonella: Cellular and Molecular Biology, and on the eve of launching a successor venture, the editors and colleagues examine where we stand in our quest for an understanding of these organisms. The main areas selected for this brief inquiry are genomics, evolution, molecular multifunctionality, functional backups, regulation of gene expression, cell biology, sensing of the environment, and ecology.
Sodium Ion Cycle in Bacterial Pathogens: Evidence from Cross-Genome Comparisons
Authors: Häse Claudia C. , Fedorova Natalie D. , Galperin Michael Y. , Dibrov Pavel A. 
Published: January 2003

SUMMARY

Analysis of the bacterial genome sequences shows that many human and animal pathogens encode primary membrane Na
+
pumps, Na
+
-transporting dicarboxylate decarboxylases or Na
+
-translocating NADH:ubiquinone oxidoreductase, and a number of Na
+
-dependent permeases. This indicates that these bacteria can utilize Na
+
as a coupling ion instead of or in addition to the H
+
cycle. This capability to use a Na
+
cycle might be an important virulence factor for such pathogens as Vibrio cholerae, Neisseria meningitidis, Salmonella enterica serovar Typhi, and Yersinia pestis. In Treponema pallidum, Chlamydia trachomatis, and Chlamydia pneumoniae, the Na
+
gradient may well be the only energy source for secondary transport. A survey of preliminary genome sequences of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Treponema denticola indicates that these oral pathogens also rely on the Na
+
cycle for at least part of their energy metabolism. The possible roles of the Na
+
cycling in the energy metabolism and pathogenicity of these organisms are reviewed. The recent discovery of an effective natural antibiotic, korormicin, targeted against the Na
+
-translocating NADH:ubiquinone oxidoreductase, suggests a potential use of Na
+
pumps as drug targets and/or vaccine candidates. The antimicrobial potential of other inhibitors of the Na
+
cycle, such as monensin, Li
+
and Ag
+
ions, and amiloride derivatives, is discussed.
Receptors and Entry Cofactors for Retroviruses Include Single and Multiple Transmembrane-Spanning Proteins as well as Newly Described Glycophosphatidylinositol-Anchored and Secreted Proteins
Authors: Overbaugh Julie , Miller A. Dusty , Eiden Maribeth V. 
Published: January 2003

SUMMARYIn the past few years, many retrovirus receptors, coreceptors, and cofactors have been identified. These molecules are important for some aspects of viral entry, although in some cases it remains to be determined whether they are required for binding or postbinding stages in entry, such as fusion. There are certain common features to the molecules that many retroviruses use to gain entry into the cell. For example, the receptors for most mammalian oncoretroviruses are multiple membrane-spanning transport proteins. However, avian retroviruses use single-pass membrane proteins, and a sheep retrovirus uses a glycosylphosphatidylinositol-anchored molecule as its receptor. For some retroviruses, particularly the lentiviruses, two cell surface molecules are required for efficient entry. More recently, a soluble protein that is required for viral entry has been identified for a feline oncoretrovirus. In this review, we will focus on the various strategies used by mammalian retroviruses to gain entry into the cell. The choice of receptors will also be discussed in light of pressures that drive viral evolution and persistence.
Human Telomerase and Its Regulation
Authors: Cong Yu-Sheng , Wright Woodring E. , Shay Jerry W. 
Published: January 2003

SUMMARYThe telomere is a special functional complex at the end of linear eukaryotic chromosomes, consisting of tandem repeat DNA sequences and associated proteins. It is essential for maintaining the integrity and stability of linear eukaryotic genomes. Telomere length regulation and maintenance contribute to normal human cellular aging and human diseases. The synthesis of telomeres is mainly achieved by the cellular reverse transcriptase telomerase, an RNA-dependent DNA polymerase that adds telomeric DNA to telomeres. Expression of telomerase is usually required for cell immortalization and long-term tumor growth. In humans, telomerase activity is tightly regulated during development and oncogenesis. The modulation of telomerase activity may therefore have important implications in antiaging and anticancer therapy. This review describes the currently known components of the telomerase complex and attempts to provide an update on the molecular mechanisms of human telomerase regulation.
Treatment models for those with severe mental illness and comorbid personality disorder
Authors: Tyrer Peter , Simmonds Shaeda 
Published: December 2002

BackgroundDual diagnosis of personality disorder and severe mental illness is an important clinical association that has been under-researched with regard to clinical management.AimsTo compare the outcomes of differenttreatment models.MethodThe outcome of patients with this combined diagnosis was compared in a systematic review of three randomised controlled trials in which different forms of community outreach treatment or intensive case management were compared with standard care.ResultsThe results from the three studies showed that the outcome of comorbid diagnoses was worse than that of single diagnoses. Although assertive approaches reduced in-patient care, they sometimes did so at the expense of increasing social dysfunction and behavioural disturbance.ConclusionsFor those with comorbid severe mental illness and personality disorder, the policy of assertive outreach and care in community settings may be inappropriate for both public and patients unless modified to take account of the special needs of this group.
Emergent Nanostructures: Water‐Induced Mesoscale Transformation of Surfactant‐Stabilized Amorphous Calcium Carbonate Nanoparticles in Reverse Microemulsions
Authors: Li M. , Mann S. 
Published: December 2002

AbstractThe water‐induced crystallization of alkylbenzenesulfonate‐coated amorphous calcium carbonate (ACC) nanoparticles in water‐in‐isooctane sodium bis(2‐ethylhexyl)sulfosuccinate (NaAOT) microemulsions at a [H2O]/[NaAOT] molar ratio (w) of 10:1 produces a range of organized hybrid surfactant–vaterite nanostructures depending on the water droplet/ACC nanoparticle number ratio,n = [H2O]/[CaCO3]. The crystalline nanostructures develop within primary aggregates of the surfactant‐stabilized ACC nanoparticles by in situ mesoscale transformation, which is mediated by the extent of coupling at the surfactant–inorganic interface. Strong coupling in the presence of low amounts of water (n = 34) gives monodisperse spheroidal aggregates of densely packed 5 nm diameter surfactant‐coated vaterite nanoparticles, whereas weak interactions atn = 3400 produce discrete vaterite nanoparticles, 130 nm in size. Significantly, intermediate levels of coupling produce anisotropic nanostructures such as spindle‐shaped aggregates of 18 nm sized surfactant‐coated vaterite nanoparticles (n = 170) and high‐aspect‐ratio bundles of co‐aligned 10 nm wide twisted vaterite nanofilaments (n = 340). Adding excess aqueous CO32–to the microemulsion droplets inhibits the growth of the nanofilaments, whereas excess Ca2+has no effect. The results show that the transformation pathways are determined by the extent of water penetration into the ACC cores and electrostatic interactions at the mineral–surfactant interface, and indicate that complex hybrid nanostructures can be assembled in situ when these processes are coupled synergistically at the mesoscopic level. Such observations could be of generic importance in nanochemistry and biomineralization.