bluuebunny/crossref_metadata_2025 huggingface dataset:
A Simple and Practical Synthetic Protocol for Acetalisation, Thioacetalisation and Transthioacetalisation of Carbonyl Compounds under Solvent‐Free Conditions
Authors: Khan Abu T. , Mondal Ejabul , Ghosh Subrata , Islam Samimul
Published: April 2004

A wide variety of carbonyl compounds can be converted smoothly to the corresponding acetals on treatment with alcohols or diols and triethyl orthoformate in the presence of a catalytic amount of (bromodimethyl)sulfonium bromide at room temperature. Similarly, various carbonyl compounds can be transformed into the corresponding dithioacetals on reaction with thiol or dithiols at room temperature by employing the same catalyst without any solvent. Moreover, O,O‐acetals can also be converted into the corresponding dithioacetals under identical conditions. Some of the major advantages are mild reaction conditions, a high degree of efficiency, compatibilty with other protecting groups and the lack of solvents, particularly for thioacetalisation. In addition, no brominations occur at the double bond or α to the keto position or even in the aromatic ring under these experimental conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis ofN‐Aryl‐5‐alkylidene‐2,5‐dihydropyrrol‐2‐ones by “Cyclization/Dimroth Rearrangement” Reactions of 1,3‐Dicarbonyl Dianions with Diimidoyl Dichlorides of Oxalic Acid
Authors: Anders Joachim T. , Görls Helmar , Langer Peter
Published: April 2004

The reaction of dilithiated dicarbonyl compounds with oxaldiimidoyl dichlorides resulted in regio‐ and (E)/(Z)‐diastereoselective formation of 5‐alkylidene‐3‐arylamino‐2,5‐dihydropyrrol‐2‐ones. The products were formed by a domino “cyclization/Dimroth rearrangement” reaction. The mechanism and preparative scope of the cyclization was studied. The arylamino groups of the products were removed chemoselectively under mild conditions and in high yields by hydrolytic cleavage. The products,N‐aryl‐5‐alkylidene‐3‐hydroxy‐2,5‐dihydropyrrol‐2‐ones, are of considerable interest from pharmacological and synthetic viewpoints. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Preparation of Axially Chiral N,N′‐Diarylimidazolium and N‐Arylthiazolium Salts and Evaluation of Their Catalytic Potential in the Benzoin and in the Intramolecular Stetter Reactions
Authors: Pesch Jens , Harms Klaus , Bach Thorsten
Published: April 2004

N‐Aryl‐substituted imidazoles 14b, 15b and thiazoles 17−22, 25 were prepared which contain a stereogenic axis and which can occur as atropisomers. The imidazolium salts 15b could be obtained from 2‐isopropylaniline (12b) and diacetyl (11) in three steps (19% yield) whereas the synthesis of their tert‐butyl analogues failed. The meso‐isomer meso‐15b prevailed (dr = 90/10). The chiral thiazolium salts rac‐17 (53% yield) and rac‐22 (49% yield) were prepared in two steps from 2‐tert‐butylaniline (12a). The enantiomerically pure thiazolium salt 19 was obtained from α‐bromomenthone (23) and the aniline 12a (27% overall yield). In contrast to the imidazolium salts 15b, the thiazolium salts proved to be suitable catalysts in the benzoin condensation of benzaldehyde (1 → 2) and in the intramolecular Stetter reaction of the α,β‐unsaturated ester 9a. The best results obtained with catalyst 19 (20 mol %) were 85% yield of product 2 (40% ee) and 75% yield of product 10a (50% ee). The stereogenic axis of catalyst 19 is not configurationally stable in the catalytically active carbene intermediate 28. The catalyst is recovered as a mixture of diastereomeric atropisomers 19 and 26 in a ratio of 70:30 to 75:25. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
The cis‐Specific Pictet−Spengler Reaction
Authors: Alberch Laura , Bailey Patrick D. , Clingan Paul D. , Mills Timothy J. , Price Richard A. , Pritchard Robin G.
Published: April 2004

The Pictet−Spengler reaction of tryptophan allyl ester with aryl aldehydes generates cis‐tetrahydro‐β‐carbolines with complete stereo‐control and with complete retention of optical integrity, when the reaction is carried out under kinetically controlled conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
An Efficient Enantioselective Synthesis of (+)‐(R,Z)‐5‐Muscenone and (−)‐(R)‐Muscone − An Example of a Kinetic Resolution and Enantioconvergent Transformation
Authors: Fehr Charles , Galindo José , Etter Olivier
Published: April 2004

An efficient catalytic kinetic resolution by CBS reduction and an original enantioconvergent transformation involving a PdII‐catalyzed position‐selective cyclization are the key steps for the synthesis of the exceptional musk odorant (R,Z)‐5muscenone [(R)‐1] and (R)‐muscone [(R)‐3]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Stroboscopic sampling in comprehensive high‐performance liquid chromatography‐capillary electrophoresis via a pneumatic sampler
Authors: Ehala Sille , Kaljurand Mihkel , Kudrjashova Marina , Vaher Merike
Published: April 2004

A new approach is presented to solve the problem of a long separation time in the second dimension of comprehensive two‐dimensional chromatography. The need for a rapid separation in the second column is overcome by repeating analysis of a sample many times. In each of these individual analysis cases the sample is injected into the first dimension column and after a delay a low amount of the effluent at the end of the first column is sampled to the second‐dimensional column. The time interval between the samplings from the first column to the second column is constantly increased. Thus, the system enables a comprehensive analysis of the effluent emerging from the first into the second column. This approach, which we call stroboscopic sampling, is tested for coupling high‐performance liquid chromatography (HPLC) to capillary electrophoresis (CE) by an interface which operates on the principle of transporting the effluent from the HPLC column to the capillary inlet by small pressure pulses (0.5 MPa). The performance of the interface for accomplishing the comprehensive HPLC‐CE analysis was demonstrated for an on‐line connection of a short ion‐exchange column and an ion‐exclusion column to the CE capillary.
Narrow‐band fractionation of proteins from whole cell lysates using isoelectric membrane focusing and nonporous reversed‐phase separations
Authors: Zhu Yi , Lubman David M.
Published: April 2004

Preparative isoelectric focusing (PIEF) is used to achieve narrow‐band fractionation of proteins from whole cell lysates of Escherichia coli (E. coli). Isoelectric membranes create well‐defined pH ranges that fractionate proteins by isoelectric point (pI) upon application of an electric potential. A commercial IsoPrime device (Amersham‐Pharmacia BioTech) is modified for the PIEF separation to lessen run volumes significantly. Two‐dimensional polyacrylamide gel electrophoresis (2‐D PAGE) analysis of chamber contents indicates that excellent pH fractionation is achieved with little overlap between chambers. PIEF pH fractions are further separated using nonporous reversed‐phase high‐performance liquid chromatography (NPS‐RP‐HPLC) and HPLC eluent is analyzed on‐line by electrospray ionization‐time of flight‐mass spectrometry (ESI‐TOF‐MS) for intact protein molecular weight (MW) analysis. The result is a pI versus MW map of bacterial protein content. IEF fractionation down to 0.1 pH units combined with intact protein MW values result in a highly reproducible map that can be used for comparative analysis of different E. coli strains.
Optimization of the separation of a group of triazine herbicides by micellar capillary electrophoresis using experimental design and artificial neural networks
Authors: Frías‐García Sergio , Sánchez M. Jesús , Rodríguez‐ Delgado Miguel Ángel
Published: April 2004

The micellar electrokinetic chromatography separation of a group of triazine compounds was optimized using a combination of experimental design (ED) and artificial neural network (ANN). Different variables affecting separation were selected and used as input in the ANN. A chromatographic exponential function (CEF) combining resolution and separation time was used as output to obtain optimal separation conditions. An optimized buffer (19.3 mM sodium borate, 15.4 mM disodium hydrogen phosphate, 28.4 mM SDS, pH 9.45, and 7.5% 1‐propanol) provides the best separation with regard to resolution and separation time. Besides, an analysis of variance (ANOVA) approach of the MEKC separation, using the same variables, was developed, and the best capability of the combination of ED‐ANN for the optimization of the analytical methodology was demonstrated by comparing the results obtained from both approaches. In order to validate the proposed method, the different analytical parameters as repeatability and day‐to‐day precision were calculated. Finally, the optimized method was applied to the determination of these compounds in spiked and nonspiked ground water samples.
Electroosmotic flow in a poly(dimethylsiloxane) channel does not depend on percent curing agent
Authors: Wheeler Aaron R. , Trapp Gabriele , Trapp Oliver , Zare Richard N.
Published: April 2004

Poly(dimethylsiloxane) (PDMS) microfluidic devices were prepared from different ratios of “curing agent” (which contains silicon hydride groups) to “base” (which contains vinyl‐terminated noncross‐linked PDMS), to determine the effect of this ratio on electroosmotic flow (EOF). In fabricating devices for this purpose, a novel method for permanently enclosing PDMS channels was developed. As a supplement to the microfluidic method, the inner walls of capillaries were coated with PDMS formed from varying ratios of curing agent to base. EOF was found to be constant for PDMS formed with each ratio, which implies that the negative surface charges do not arise from chemical species present only in the base or the curing agent.
Thermoresponsive N,N‐dialkylacrylamide copolymer blends as DNA sieving matrices with a thermally tunable mesh size
Authors: Kan Cheuk‐Wai , Doherty Erin A. S. , Buchholz Brett A. , Barron Annelise E.
Published: April 2004

In an earlier study we showed that a blend of thermoresponsive and nonthermoresponsive hydroxyalkylcelluloses could be used to create a thermally tunable polymer network for double‐stranded (ds) DNA separation. Here, we show the generality of this approach using a family of polymers suited to a wider range of DNA separations: a blended mixture of N,N‐dialkylacrylamide copolymers with different thermoresponsive behaviors. A mixture of 47% w/w N,N‐diethylacrylamide (DEA)/53% w/w N,N‐dimethylacrylamide (DMA) (DEA47; thermoresponsive, transition temperature = 55°C in water) and 30% w/w DEA/70% w/w DMA (DEA30; nonthermoresponsive, transition temperature > 85°C in water) copolymers in the ratio of 1:5 w/w DEA47:DEA30 was used to separate a dsDNA restriction digest (ΦX174‐HaeIII). We investigated the effects of changing mesh size on dsDNA separation, as controlled by temperature. We observed good DNA separation performance with the copolymer blend at temperatures ranging from 25°C to 48°C. The separation selectivity was evaluated quantitatively for certain DNA fragment pairs as a function of temperature. The results were compared with those obtained with a control matrix consisting only of the nonthermoresponsive DEA30. Different DNA fragment pairs of various sizes show distinct temperature‐dependent selectivities. Over the same temperature range, no significant temperature dependence of selectivity is observed for these DNA fragment pairs in the nonthermoresponsive control matrix. Overall, the results show similar trends in the temperature dependency of separation selectivity to what was previously observed in hydroxyalkylcellulose blends, for the same DNA fragment pairs. Finally, we showed that a ramped temperature scheme enables improved separation in the blended copolymer matrix for both small and large DNA fragments, simultaneously in a single capillary electrophoresis (CE) run.
Peptide and protein separations by capillary electrophoresis in the presence of mono‐ and diquaternarized diamines
Authors: Pontoglio Alessandro , Viganò Agnese , Sebastiano Roberto , Citterio Attilio , Maragnoli Luca , Righetti Pier Giorgio , Gelfi Cecilia
Published: April 2004

Two compounds, derivatives of 1,4‐diazobicyclo[2,2,2]octane (DABCO), have been evaluated as potential quenchers of silanol interactions with peptides and proteins during their capillary zone electrophoresis (CZE) separations. They are: 1‐(4‐iodobutyl)4‐aza‐1‐azoniabicyclo[2,2,2]octane iodide (M7C4I) and 1,4‐didecyl‐1,4‐diazoniabicyclo [2,2,2]octane dibromide (C10M7C10). The first compound is known to react with the wall, by forming a covalent bond via alkylation of silanols. On the contrary, the second one (C10M7C10) can only loosely interact with silica due to lack of reactive iodine and to a much too short distance (a C2) between the two quaternary nitrogens. Very good peptide maps of protein digests can be obtained in isoelectric glutamic acid (Glu) buffer, at pH 3.52 by utilizing the M7C4I. However, in the case of total tissue extracts, excellent resolution is obtained only with the first eluting part of the analyte spectrum (i.e., peptides and smaller proteins). With larger proteins, interaction with the wall and loss of resolution is experienced. When using the C10M7C10, good resolution of di‐ and tripeptides is obtained, while a loss of resolution is observed with entire protein digest. M7C4I does not seem to interact with the peptide/protein analytes, and simply repels them from the wall via its positive charges; it is believed that disalt (C10M7C10) acts by interacting with the same compounds, possibly by forming micelles in solution.
Separation and determination of biphenyl nitrile compounds by microemulsion electrokinetic chromatography with mixed surfactants
Authors: Gong Suxuan , Bo Tao , Huang Lan , Li Ke An , Liu Huwei
Published: April 2004

A mixture of six biphenyl nitrile compounds and three related substances with high hydrophobicity and similar structures was successfully separated by microemulsion electrokinetic chromatography (MEEKC) within 30 min. The microemulsion system contained 100 mM sodium dodecyl sulfate (SDS), 80 mM sodium cholate (SC), 0.81% v/v heptane, 7.5% v/v n‐butanol, 10% v/v acetonitrile, and 10 mM borate. The addition of SC, organic modifiers, sample preparation, and temperature all showed remarkable effects on the separation. The capacity factor (k) was calculated by using dodecyl benzene as the marker for microemulsion, and the calculated partition coefficient log Po/w of the solutes was in the range of 3.35–7.38. The log k values matched well with the log Po/w with a correlation coefficient of 0.96. In addition, the linear correlation coefficients of each compound between peak area and concentration were from 0.996 to 0.998 with the repeatability RSD value < 1.2% for migration time and < 4.8% for peak area, and the highest theoretic plate number was > 586 000. MEEKC was compared with micellar electrokinetic chromatography (MEKC) indicating that the former method is more suitable for this separation and can be used for the quality control of biphenyl nitrile compounds in the synthesis of liquid crystals.
Fast and simple method for determination of iodide in human urine, serum, sea water, and cooking salt by capillary zone electrophoresis
Authors: Pantůčková Pavla , Křivánková Ludmila
Published: April 2004

For the determination of iodide in urine, where 80–90% of consumed iodine is excreted, a fast, simple, and sensitive method of capillary zone electrophoresis was elaborated and tested also for additional complex matrices such as human serum, cooking salt, and seawater. Several approaches were examined for the separation of iodide from other macro‐ and microcomponents in the tested matrices, and the best results were obtained when host‐guest interaction with α‐cyclodextrin or ion‐pairing with polyethylenimine was employed. In both cases comparable resolution and sensitivity were reached. Due to the relatively high price of cyclodextrin only the method with polyethylenimine was further optimized and a simple procedure enabling the determination of iodide in untreated human urine, serum, cooking salt, and seawater was elaborated. The samples were injected for 20 s at 0.5 psi (3.45 kPa) into a fused‐silica capillary (0.18 mm ID, 50 cm effective length) coated with polyacrylamide (electroosmotic flow < 2×10−9 m2V−1s−1) and filled with the optimized background electrolyte composed of 20 mM KH2PO4 and 0.7% m/v polyethylenimine. For detection, UV absorption at 200 and 230 nm was measured. Concentration limits of detection reached at 230 nm were for human urine 0.14 μM, for human serum 0.17 μM, for seawater 0.17 μM, and for cooking salt 89 nM. Relative standard deviations of iodide peak area and height in all matrices ranged within 0.93 to 4.19%.
Micellar electrokinetic chromatography of enkephalin‐related peptides with laser‐induced fluorescence detection
Authors: Huang Ying , Duan Jianping , Chen Qiaoren , Chen Guonan
Published: April 2004

Eight enkephalin‐related peptides were derivatized using fluorescein isothiocyanate (FITC), and the derivatization products were separated and detected by capillary electrophoresis with laser‐induced fluorescence detection. The optimum molar ratio of FITC and peptide for derivatization was found to be 40:1, and 5 mmol/L sodium borate buffer (pH 9.2) was selected as derivatization media in order to get the high efficiency. Enkephalin‐related peptides were completely separated in the pH range of 10.51–10.60 in a running buffer consisting of 100 mmol/L sodium borate and 60 mmol/L sodium dodecyl sulfate (SDS). The detection limit for these eight enkephalins ranged from 0.18 to 2.25 nmol/L, and the linear response range was 1.0×10−6 to 1.0×10−9 mol/L with correlation coefficients between 0.9947–0.9988. A separation efficiency as high as 380 000 theoretical plates could be obtained for these analytes.
Development and modeling of a frictional wall damper and its applications in reinforced concrete frame structures
Authors: Cho Chang‐Geun , Kwon Minho
Published: April 2004

A wall‐type friction damper is newly proposed in this paper to improve the performance of reinforced concrete (RC) framed structures under earthquake loads. Traditionally, the damper was generally invented as a brace‐type member. However, it has been seen to cause problems in the RC frame structures in that concrete is apt to be damaged in the connection regions of the RC member and the brace‐type damper under earthquake loads. The proposed wall‐type damper has an advantage in the retrofit of RC structures. The system consists of a Teflon® slider and a RC wall. The damper is also designed to control normal pressures acting on a frictional slider. The numerical applications show that the proposed damper can be effective in mitigating the seismic responses of RC frame structures and reducing the damage to RC structural members. Copyright © 2004 John Wiley & Sons, Ltd.
Case study: Environmental monitoring using remote optical sensing (OP‐FTIR) technology at the Oklahoma City Air Logistics Center industrial wastewater treatment facility
Authors: Hall Freddie E.
Published: April 2004

During production and maintenance operations at Tinker Air Force Base in Oklahoma City, Oklahoma, industrial wastewater streams are generated that contain organic and heavy metal compounds. These waste streams result from chemical depainting operations, chemical cleaning processes, and electroplating operations. Processes discharging wastewater are treated at the on‐site industrial wastewater treatment facility (IWTF). Regulatory reporting mandates require identifying volatile organic compound emission sources, estimating emissions from the IWTF, quantifying ambient air concentrations surrounding the facility via air dispersion modeling, and evaluating computer‐generated numerical concentration estimates with respect to discontinuous field data and an open‐path optical remote monitoring system. The objective of this article is to compare three strategies for meeting air‐quality management requirements: (1) the use of a coupled model (air emission model and air dispersion model); (2) the use of air quality–monitoring data collected via discontinuous air sampling and analysis (i.e., periodic canister monitoring); and (3) the use of air‐quality data generated by open‐path optical remote monitoring using Fourier Transform Infrared Spectroscopy (OP‐FTIR). Validation of the predictive accuracy of the three strategies will be made based on (a) comparisons and statistical testing of receptor location predictions with air‐quality data from periodic canister monitoring; (b) comparisons and statistical testing of predictions along the open‐path optical remote monitoring boundary line with measured concentrations based on OP‐FTIR; and (c) comparisons and statistical testing of pertinent field canister monitoring data with open‐path monitoring results. © 2004 Wiley Periodicals, Inc.
Motivation for environmental construction
Authors: Siddiqi Khalid M. , Oberle Rita , Thomas‐Mobley Linda , Kangari Roozbeh
Published: April 2004

Environmental laws are increasing and changing faster than they can be implemented in the construction industry. This is especially important for federal facilities and environmental construction because federal agencies are strongly averse to notices of violation to environmental regulations. Other industries, such as the Air Force aircraft development industry, are coping with problems related to impacts of environmental laws by integrating the concept of design for environment into their management strategy on a life‐cycle basis. The construction industry has historically addressed environmental regulations in a segregated and fragmented approach and seen environmental issues as restrictions and constraints. With the advent of sustainability in construction and bioremediation in environmental construction, federal agencies also need to address the problem in an integrated fashion by improving its project management, planning, and implementation strategies. This article presents a framework that can be used by the construction industry for analyzing construction alternatives in an integrated fashion with respect to environmental laws and regulations. The framework provides a holistic approach for taking into consideration public needs, construction processes, and regulatory governmental functions. The framework can be used by federal agencies for addressing life‐cycle environmental issues pertaining to compliance, conservation, and pollution prevention. Use of the holistic approach and integrated framework is expected to minimize remediation in new building and environmental construction projects. © 2004 Wiley Periodicals, Inc.
Biophysical and pharmacological characterization of hypotonically activated chloride currents in cortical astrocytes
Authors: Parkerson Kimberly A. , Sontheimer Harald
Published: April 2004

Rat cortical astrocytes regulate their cell volume in response to hypotonic challenge. This regulation is believed to depend largely on the release of chloride or organic osmolytes through anion channels. Using whole‐cell recordings, we identified weakly outwardly rectifying chloride currents that could be activated in response to hypotonic challenge. These currents exhibited the following permeability sequence upon replacement of chloride in the bathing solution with various anions: I−>NO3−>Cl−>Gluc− ≥MeS−>Ise−. Interestingly, extracellular I−, albeit showing the greatest permeability, blocked the currents with an IC50 of ≈50 mM. Currents were almost completely inhibited by 123 μM NPPB and partially inhibited by 200 μM niflumic acid or 200 μM DIDS. Additionally, the total number of Cl− ions effluxed through the hypotonically activated channels was markedly similar to the total solute efflux during volume regulation. We therefore propose the hypotonically activated chloride channel as a major contributor to volume regulation of astrocytes. To examine potential candidate chloride channel genes expressed by astrocytes, we employed RT‐PCR to demonstrate the presence of transcripts for ClC‐2, 3, 4, 5, and 7, as well as for VDAC and CFTR in cultured astrocytes. Moreover, we performed immunostaining with antibodies against each of these channels and showed the strongest expression of ClC‐2 and ClC‐3, strong expression of ClC‐5 and VDAC, weak expression of ClC‐7 and very weak expression of ClC‐4 and CFTR. Intriguingly, although we found at least seven Cl− channel proteins from three different gene families in astrocytes, none appeared to be active in resting cells. © 2004 Wiley‐Liss, Inc.
Properties of Ca2+‐dependent exocytosis in cultured astrocytes
Authors: Kreft Marko , Stenovec Matjaž , Rupnik Marjan , Grilc Sonja , Kržan Mojca , Potokar Maja , Pangršič Tina , Haydon Philip G. , Zorec Robert
Published: April 2004

Astrocytes, a subtype of glial cells, have numerous characteristics that were previously considered exclusive for neurons. One of these characteristics is a cytosolic [Ca2+] oscillation that controls the release of the chemical transmitter glutamate and atrial natriuretic peptide. These chemical messengers appear to be released from astrocytes via Ca2+‐dependent exocytosis. In the present study, patch‐clamp membrane capacitance measurements were used to monitor changes in the membrane area of a single astrocyte, while the photolysis of caged calcium compounds by a UV flash was used to elicit steps in [Ca2+]i to determine the exocytotic properties of astrocytes. Experiments show that astrocytes exhibit Ca2+‐dependent increases in membrane capacitance, with an apparent Kd value of ∼20 μM [Ca2+]i. The delay between the flash delivery and the peak rate in membrane capacitance increase is in the range of tens to hundreds of milliseconds. The pretreatment of astrocytes by the tetanus neurotoxin, which specifically cleaves the neuronal/neuroendocrine type of SNARE protein synaptobrevin, abolished flash‐induced membrane capacitance increases, suggesting that Ca2+‐dependent membrane capacitance changes involve tetanus neurotoxin‐sensitive SNARE‐mediated vesicular exocytosis. Immunocytochemical experiments show distinct populations of vesicles containing glutamate and atrial natriuretic peptide in astrocytes. We conclude that the recorded Ca2+‐dependent changes in membrane capacitance represent regulated exocytosis from multiple types of vesicles, about 100 times slower than the exocytotic response in neurons. © 2004 Wiley‐Liss, Inc.
Psychometric properties and factor structure of the Neuropsychiatric Inventory Nursing Home version in an elderly neuropsychiatric population
Authors: Lange Rael T. , Hopp Grace A. , Kang Nirmal
Published: April 2004

Background

The Neuropsychiatric Inventory (NPI) is an interview‐based instrument designed to elicit information from an informal caregiver to evaluate behavioral disturbances in persons with dementia. Minor modifications of this instrument have produced the Neuropsychiatric Inventory—Nursing Home version (NPI‐NH), a version specifically designed for interviewing professional care facility staff. The purpose of this investigation is to further understand the psychometric properties of the NPI‐NH by examining its reliability, validity, and factor structure in an elderly neuropsychiatric population.

Method

Participants were 204 elderly inpatients from a large provincial neuropsychiatric hospital in British Columbia, Canada. Data were collected as part of a patient needs assessment project.

Results

The internal consistency reliability of the NPI‐NH was α=0.67. An exploratory principal axis analysis with varimax rotation revealed five factors that accounted for 63.2% of the variance. These factors reflect aspects of psychiatric disturbance associated with: (a) Agitation; (b) Mood; (c) Psychosis; (d) Sleep/Motor Activity; and (e) Elevated Behavior. Convergent and discriminant validity of the five factors by correlating them with other behavioral measures was considered satisfactory.

Conclusions

These results provide support for the clinical use of the NPI‐NH as a screen for neuropsychiatric symptoms in an elderly neuropsychiatric population. However, additional research is encouraged to further evaluate the clinical utility of the NPI‐NH in nursing home and inpatient geriatric settings. Copyright © 2004 John Wiley & Sons, Ltd.
Childlessness and psychological well‐being in Chinese older adults
Authors: Chou Kee‐Lee , Chi Iris
Published: April 2004

Background

Childless older adults will increase rapidly in the coming future due to delayed marriage, infertility, and high divorce rate. We examined whether childlessness is significantly related to loneliness and depression and whether the effect of childlessness persisted even when other factors including gender, marital status, age, education, self‐rated health status and financial strain were controlled for.

Method

This article analyzes cross‐sectional data collected from a representative community sample of 2003 Chinese elderly people aged 60 or above in Hong Kong. Respondents were interviewed in face‐to‐face format and data including socio‐demographic variables, health indicators, loneliness and depression were obtained.

Result

Logistic regression analyses revealed that childlessness was significantly related to loneliness and depression even after marital status, gender, age, education, self‐reported health status, and financial strain were controlled for.

Conclusion

The impact of childlessness on psychological well‐being among elderly Chinese is more robust than that found in older Americans. Moreover, consistent with the findings of previous studies, we found that the effect of childlessness on psychological well‐being has to be investigated in the context of marital status. Therefore, aged care service practitioners must take this risk factor into consideration in their preventive intervention and treatment for psychological well‐being. Copyright © 2004 John Wiley & Sons, Ltd.
Validation of short screening tests for depression and cognitive impairment in older medically ill inpatients
Authors: Goring Hannah , Baldwin Robert , Marriott Alison , Pratt Helen , Roberts Chris
Published: April 2004

Objective

To investigate the criterion validity of the four‐item Geriatric Depression Scale (GDS4) and the six‐item Orientation‐Memory‐Concentration‐test (OMC) against longer widely used screening instruments.

Method

Participants were 153 patients (aged 65 or over) admitted to four acute medical wards of a northern UK town. The validity of the GDS4 was determined using the 30‐item geriatric depression scale (GDS30) as the comparator; the validity of the OMC was determined using the standardised mini‐mental state examination (MMSE) as the comparator. For both screens, the area under receiver operating characteristic (ROC) curve was calculated in addition to the number of true and false positives and the sensitivity and specificity for various cut‐off points.

Results

The area under ROC curve was 0.80 for the GDS4 and 0.90 for the OMC. Using a cut‐off of 0/1, the GDS4 correctly classified 78.2% of participants, using the GDS30 as the standard. This cut‐off gave a sensitivity of 90.1% and specificity of 55.3%. With a cut‐off of 1/2 the GDS4 correctly classified 76.8% of participants and had sensitivity and specificity of 78% and 74.5% respectively. The GDS4 and GDS30 were highly correlated (rho=0.63, p < 0.0005). A cut‐off of 10/11 on the OMC gave optimum performance. With this cut‐off, it correctly classified 85.9% of participants, and had 85.6% sensitivity and 86.8% specificity. There was a significant correlation between the OMC and the SMMSE (rho = −0.827, p < 0.0005).

Conclusion

The GDS4 and OMC appear to be useful instruments for screening for depression and cognitive impairment among older medical inpatients. Copyright © 2004 John Wiley & Sons, Ltd.
Intentions of first‐degree relatives of patients with Alzheimer's disease to seek a cognitive status examination
Authors: Werner Perla , Heinik Jeremia
Published: April 2004

Aims

The aim of the present study was to examine the factors influencing intentions to seek a cognitive status evaluation among first‐degree relatives of persons with Alzheimer's disease.

Methods

Phone interviews were conducted with 93 first‐degree relatives of persons with Alzheimer's disease, recruited from a large memory clinic.

Measures

Intentions to seek a cognitive status examination were examined by asking participants to rate their willingness to seek a cognitive status examination during the next year and during the next five years. Independent variables included participants' and patients' characteristics, caregiving characteristics, knowledge about AD, worries about memory problems, and perceptions of the benefits and barriers of seeking a cognitive status examination.

Results

Overall, first‐degree relatives reported only moderate intentions to seek a cognitive status examination. Their willingness to seek an examination was related to the characteristics of the first‐degree relative (income and subjective memory), the characteristics of the patients (behavioral problems), the caregiving characteristics (primary caregiver), and to the perceptions of barriers associated with the examination.

Conclusions

These findings stress the complexity of the decision‐making process confronting first‐degree relatives regarding their intentions to seek a cognitive status examination, and suggest the need to provide information to reach an informed decision. Copyright © 2004 John Wiley & Sons, Ltd.
Method for bias field correction of brain T1‐weighted magnetic resonance images minimizing segmentation error
Authors: Gispert Juan D. , Reig Santiago , Pascau Javier , Vaquero Juan J. , García‐Barreno Pedro , Desco Manuel
Published: April 2004

This work presents a new algorithm (nonuniform intensity correction; NIC) for correction of intensity inhomogeneities in T1‐weighted magnetic resonance (MR) images. The bias field and a bias‐free image are obtained through an iterative process that uses brain tissue segmentation. The algorithm was validated by means of realistic phantom images and a set of 24 real images. The first evaluation phase was based on a public domain phantom dataset, used previously to assess bias field correction algorithms. NIC performed similar to previously described methods in removing the bias field from phantom images, without introduction of degradation in the absence of intensity inhomogeneity. The real image dataset was used to compare the performance of this new algorithm to that of other widely used methods (N3, SPM'99, and SPM2). This dataset included both low and high bias field images from two different MR scanners of low (0.5 T) and medium (1.5 T) static fields. Using standard quality criteria for determining the goodness of the different methods, NIC achieved the best results, correcting the images of the real MR dataset, enabling its systematic use in images from both low and medium static field MR scanners. A limitation of our method is that it might fail if the bias field is so high that the initial histogram does not show bimodal distribution for white and gray matter. Hum. Brain Mapping 22:133–144, 2004. © 2004 Wiley‐Liss, Inc.
Fibrogenic effect of oxidative stress on rat hepatic stellate cells
Authors: Baroni Gianluca Svegliati , D’Ambrosio Letizia , Ferretti Gianna , Casini Alessandro , Di Sario Antonio , Salzano Renata , Ridolfi Francesco , Saccomanno Stefania , Jezequel Anne Marie , Benedetti Antonio
Published: April 2004

Oxidative stress is associated with liver fibrosis and with hepatic stellate cell (HSC) activationin vivo. However, it remains controversial whether oxidative stress contributes to HSC activation either directly or through a paracrine stimulation by damaged hepatocytes. A medium containing products released from cells undergoing oxidative stress was obtained after incubation of hepatocytes with (HCM/Fe) or without (HCM) 0.1 mmol/L ferric nitrilotriacetate complex (FeNTA). Exposure of HSC to HCM/Fe for 24 hours significantly increased the number of proliferating HSC compared with HCM and to controls at all dilutions tested. The simultaneous coincubation of HSC with HCM/Fe and desferrioxamine (50 μmol/L) did not reduce the observed increase in cell proliferation, thus excluding a role for eventually contaminating iron in HCM/Fe. HCM/Fe induced also a significant increase in collagen type I accumulation in HSC culture media. To study the cellular mechanism underlying HCM/Fe effects, we evaluated the activity of the Na+/H+exchanger, which plays a role in regulating HSC proliferation. The incubation of HSC for 24 hours with HCM/Fe significantly increased baseline intracellular pH (pHi) and Na+/H+exchanger activity, indicating a plausible role of this antiport in mediating cell response. In conclusion, hepatocytes undergoing oxidative stress release factors which are fibrogenic for HSC, thereby, confirming what has been only hypothesizedin vivo. In addition, HSC proliferation is associated with changes in the Na+/H+exchanger activity, thus providing a useful target for the evaluation of inhibitors of this pathway for the treatment of hepatic fibrosis.
The human gallbladder increases cholesterol solubility in bile by differential lipid absorption: A study using a new in vitro model of isolated intra-arterially perfused gallbladder
Authors: Corradini Stefano Ginanni , Ripani Cristina , Della Guardia Paola , Giovannelli Luca , Elisei Walter , Cantafora Alfredo , Pisanelli Massimo Codacci , Tebala Giovanni Domenico , Nuzzo Gennaro , Corsi Alessandro , Attili Adolfo Francesco , Capocaccia Livio , Ziparo Vincenzo
Published: April 2004

In this study, we first developed and validated a newin vitroisolated, intra-arterially perfused, gallbladder model and then applied the method to investigate the absorption of biliary lipids by the gallbladder wall and the effect of this process on the composition of human bile. Oxygenated and glucose-added buffer was perfused through the cystic artery to maintain organ viability. A standard pooled natural bile, radiolabeled with H3-cholesterol and C14-palmitoyl-linoleoyl-phosphatidylcholine, was instilled in the lumen via a cystic duct catheter. Changes in bile volume and lipid concentrations were monitored at time intervals to evaluate the disappearance of lipids from bile caused by gallbladder absorptive function. Organ viability was demonstrated by stable lactate dehydrogenase (LDH) organ release and oxygen consumption throughout the experiments. In the pig, disappearance rates of lipids from bile were similarin vitroandin vivo,demonstrating the validity of the isolatedin vitromodel for functional studies. By applying ourin vitroisolated preparation to the human gallbladder, we found that 23% of cholesterol and 32% of phosphatidylcholine, but only 9% of bile salts, disappeared from bile in 5 hours. As a consequence, at the end of the experiments, cholesterol (P< .05) and phospholipid (P< .05) molar percentages were significantly reduced, while the bile salt (P< .05) molar percentage was significantly increased with respect to values at the beginning of the studies. Our findings are of pathophysiological relevance and support the concept that the human gallbladder modifies the relative composition of biliary lipids in such a way as to increase cholesterol solubility in bile.
Expressive and receptive language skills of temperamentally shy preschoolers
Authors: Spere Katherine A. , Schmidt Louis A. , Theall‐Honey Laura A. , Martin‐Chang Sandra
Published: April 2004

Although shy children speak less in social situations, the extent to which their language skills fall behind those of their more outgoing peers remains unclear. We selected 22 temperamentally shy and 22 non‐shy children from a larger group of 400 4‐year‐old children who were prescreened for temperamental shyness by maternal report, using the Colorado Childhood Temperament Inventory (CCTI). We then compared the two groups on widely used measures that index expressive and receptive language skills. We found that, although the temperamentally shy children scored lower on both expressive and receptive language skills compared with their non‐shy counterparts, they were nonetheless performing at their age equivalency. The non‐shy children, however, were performing significantly above their age level on expressive and receptive language skills. These findings suggest that the development of normal language skills is not compromised in temperamentally shy preschoolers. Copyright © 2004 John Wiley & Sons, Ltd.
Perceived mother‐infant relationship difficulties in postnatal depression
Authors: Loh Chun‐Chong , Vostanis Panos
Published: April 2004

Postnatal depression has been associated with mother–infant relationship difficulties, but there has been less research in clinical populations. This study aims to identify characteristics of reported mother–infant relationship difficulties in mothers with postnatal depression who had been referred to a tertiary Mother and Baby Service. Forty‐one mothers with postnatal depression completed self‐report and interview measures with regards to their mental state, social adversity, and perceptions on their relationship with their infants. Almost one‐third of mothers (31.7%) reported severe difficulties, including rejection of the infant and maternal pathological anger. A low birth weight and maternal dissatisfaction towards their social role were found to be significantly related to perceived mother–infant interaction difficulties. Self‐reports correlated satisfactorily with interview schedules. A significant proportion of mothers reported difficulties in relating to their infants which can be reliably identified by means of the self‐report measures used. Copyright © 2004 John Wiley & Sons, Ltd.
Visuo‐spatial abilities in autism: A review
Authors: Mitchell Peter , Ropar Danielle
Published: April 2004

Individuals with autism show various signs of heightened abilities in visuo‐spatial functioning. First, it is long‐established that they excel on embedded figures and block design tests relative to comparison participants. Second, some evidence suggests that processing global features is affected by inappropriate processing of the constituent elements of a stimulus. Third, they are more accurate than comparison participants in judging the shape of a slanted circle in a context in which ambient visual cues are eliminated. This suggests that their perception of the shape is less influenced by prior knowledge. Fourth, they are fast at searching for feature and conjunctive targets in a visual array. Contrary to earlier reports, however, they are susceptible to visual illusions. Also, they do show evidence of utilising prior knowledge when pairing a colour with an atypically coloured target. Accordingly, we conclude that there is something distinctive about autistic visuo‐spatial functioning, but not necessarily in ways that are predicted by the ‘weak central coherence’ hypothesis. Copyright © 2004 John Wiley & Sons, Ltd.
Imaginary companions: An evaluation of parents as reporters
Authors: Gleason Tracy R.
Published: April 2004

Parents are often solicited as reporters on their children's imaginary companions (ICs), but the correspondence between their reports and children's descriptions of pretend friends has received little attention. Sixty 4‐year‐old children and their parents provided descriptions of the children's interest in fantasy play, and 40 of these pairs also reported on children's ICs (20 on invisible friends and 20 on personified objects such as dolls). Results indicated that reports from parents of children with ICs matched their children's reports for involvement in fantasy play better than those of parents of children without ICs. For both IC groups, parents' reports concurred with children's for IC form, sex and physical description, but overall, parent–child agreement was higher for invisible friends than for personified objects. Results imply that parents may be better reporters of normative developmental processes that are slightly atypical than those that are common to most children. Copyright © 2004 John Wiley & Sons, Ltd.
Modified adenoviruses for cancer gene therapy
Authors: Kanerva Anna , Hemminki Akseli
Published: April 2004

Adenoviral gene therapy is an exciting novel approach for treating cancers resistant to currently available therapies. However, currently there is little evidence supporting significant clinical benefits with replication‐incompetent adenoviruses. Recent data suggest that expression of the primary receptor, the coxsackie‐adenovirus receptor (CAR), may be highly variable on tumor cells, resulting in resistance to infection. Consequently, various strategies have been evaluated to modify adenovirus tropism in order to circumvent CAR deficiency, including retargeting complexes or genetic capsid modifications. To improve tumor penetration and local amplification on the antitumor effect, selectively oncolytic agents, i.e., conditionally replicating adenoviruses, have been constructed. Infection of tumor cells results in replication, oncolysis and subsequent release of the virus progeny. Normal tissue is spared due to lack of replication. This review focuses on the various modifications that have been investigated for improving the antitumor effect of adenoviral gene therapy. © 2004 Wiley‐Liss, Inc.
Education and risk of breast cancer in the Norwegian‐Swedish women's lifestyle and health cohort study
Authors: Braaten Tonje , Weiderpass Elisabete , Kumle Merethe , Adami Hans‐Olov , Lund Eiliv
Published: April 2004

A positive relationship between level of education and female breast cancer risk is well supported by scientific evidence, but few previous studies could adjust for all relevant potential confounding factors. The authors' purpose was to examine how risk for breast cancer varies with level of education and to identify factors that explain this variation, using data from a prospective cohort study including 102,860 women from Norway and Sweden who responded to an extensive questionnaire in 1991/1992; 1,090 incident primary invasive breast cancer cases were revealed during follow‐up, which ended in December 1999. The Cox Proportional Hazards Model was used to calculate relative risks (RR) with 95% confidence intervals (CI). Women with more than 16 years of education had a 36% increased risk compared to the lowest educated (7–9 years) (Age adjusted RR=1.36, 95% CI: 1.10, 1.68). This relationship was slightly stronger among postmenopausal (RR 1.51) than among premenopausal (RR 1.25) women. In both groups, however, the relative risk estimates turned close to unity by adjustment for parity, age at first birth, body mass index (BMI), height, age at menarche, menopausal status, use of oral contraceptives and consumption of alcohol. The overall multivariate relative risk among the highest educated women was 1.04 (95% CI 0.82–1.32). The results of our study suggest a clear positive gradient in risk for breast cancer by level of education, which can be fully explained by established breast cancer risk factors. © 2004 Wiley‐Liss, Inc.