SEARCH · PubMed Health

Results for “Paper”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources

PubMed1991

Determination of mefloquine in blood, filter paper-absorbed blood and urine by 9-fluorenylmethyl chloroformate derivatization followed by liquid chromatography with fluorescence detection.

We describe a method for determination of mefloquine (MQ) in 100-microliters samples of urine, whole blood, and capillary blood collected on filter paper; quantification is by liquid chromatography with fluorescence detection at 475 nm of the 9-fluorenylmethyleneoxycarbonyl derivative. Whole blood and urine samples were prepared by extraction of MQ and internal standard from aqueous base with methyl tert.-butyl ether (MTBE), separation and evaporation of the MTBE layer, and derivatization using a solution of 9-fluorenylmethyl chloroformate in acetonitrile. Filter paper spots were immersed for 16 h in 0.1 M hydrochloric acid, followed by extraction with MTBE from aqueous sodium carbonate. The separated and evaporated organic layer was treated with the derivatizing solution. An aliquot was injected onto a high-performance liquid chromatography system using a C18 reversed-phase column and acetonitrile-water (72:28) mobile phase for filter paper spot extracts as for whole blood and urine extracts. The method has a limit of determination in blood, blood spots, and urine of 50 ng/ml with 100 microliters sample size (coefficient of variation = 16%). Linearity and precision (within-day and between-day) for the method are good. The MQ derivative was isolated and characterized spectroscopically. Values for MQ concentrations in filter paper blood spots compared favorably with values found in corresponding whole blood samples analyzed by a published method.

Chromatography, High Pressure Liquid↗

PubMed2005

Heuristic evaluation of paper-based Web pages: a simplified inspection usability methodology.

Online medical information, when presented to clinicians, must be well-organized and intuitive to use, so that the clinicians can conduct their daily work efficiently and without error. It is essential to actively seek to produce good user interfaces that are acceptable to the user. This paper describes the methodology used to develop a simplified heuristic evaluation (HE) suitable for the evaluation of screen shots of Web pages, the development of an HE instrument used to conduct the evaluation, and the results of the evaluation of the aforementioned screen shots. In addition, this paper presents examples of the process of categorizing problems identified by the HE and the technological solutions identified to resolve these problems. Four usability experts reviewed 18 paper-based screen shots and made a total of 108 comments. Each expert completed the task in about an hour. We were able to implement solutions to approximately 70% of the violations. Our study found that a heuristic evaluation using paper-based screen shots of a user interface was expeditious, inexpensive, and straightforward to implement.

Computer Graphics↗

PubMed2006

Surface-enhanced Raman scattering of single-walled carbon nanotubes on silver-coated and gold-coated filter paper.

Surface-enhanced Raman scattering (SERS) spectra of single-walled carbon nanotubes (SWCNTs) on metal-coated filter paper are reported for the first time. Experimental results show that the metal-coated filter paper is very effective and active. The SERS spectrum not only shows that all Raman bands of SWCNTs in normal Raman scattering have been generally enhanced, but also shows many new bands, which characterize the structure of SWCNTs and the interaction between SWCNTs and silver/gold nanoparticles, arising from symmetry lowering and selection rule relaxing of SWCNTs induced by the silver/gold surface. In our case, it is difficult to separate the contributions of the electromagnetic and chemical mechanisms to the great enhancement of the Raman signal. The analysis shows that the SERS spectra of SWCNTs on the metal-coated filter paper provide convenience for probing the sample molecules with fine structures related to defects of SWCNTs, the diameter of SWCNTs, and the SERS mechanism of SWCNTs deposited on metal-coated filter paper. Moreover, this can be used as a probe technique for monitoring the synthesis quality of SWCNTs with significant higher sensitivity than other methods, which has promise of being a new technique for monitoring synthesis quality of SWCNTs.

Journal Article↗

PubMed2005

Ethnographic component and organism documentation in an ethnopharmacology paper: a "minimum" standard.

The ethnographic component (traditional/indigenous therapeutic uses of plants or animals, specific contexts of use, preparation, dosage, route of administration) published in the Journal of Ethnopharmacology (JEP) has not been consistently and fully provided in the past. In an attempt to ensure the fulfillment of these criteria, hence, the fulfillment of the scope of papers published in this journal, starting with the February, 2004 issue of JEP (vol. 90, 2004), the journal provided detailed "Guide to Authors", "Author Checklist", and models of ethnopharmacology papers. An analysis of research papers published in JEP vols. 98 and 99 showed that these papers still have not achieved full compliance with the interdisciplinarity/multidisciplinarity nature of the journal, and the discipline. Thus, a minimum standard for the ethnographic component is set down.

Anthropology, Cultural↗

PubMed2005

Measurement of net acid excretion by use of paper strips.

OBJECTIVE: Net endogenous acid production, reflected in the steady state as net acid excretion (NAE), is implicated in bone loss because it is positively associated with urinary calcium loss. Protein is one of the main sources of dietary acid load, whereas fruit and vegetables provide alkaline potassium salts that counteract the dietary acid load. This study investigated whether a pH paper strip measurement of overnight (i.e., first void) urine would reflect 24-h NAE, measured as excretion rates of titratable acid minus bicarbonate plus ammonium. METHODS: Twenty-three subjects collected 24-h urine in two parts: day (approximately 7 am to 11 pm) and overnight (approximately 11 pm to 7 am). At first void, subjects recorded pH using paper strips. Subjects recorded intake and 20 subjects provided fasting urine collected from 7 to 9 am. RESULTS: The pH paper strip measurements of first void urine was significantly correlated with 24-h titratable acid minus bicarbonate (r = -0.466, P < 0.025) but not with 24-h NAE. We examined the association of dietary protein, potassium, protein:potassium ratio, and sodium with NAE, with fasting morning urinary calcium excretion, an indirect measurement of bone loss, and with urinary cross-links, a direct measurement of bone resorption. Of these, only sodium intake (measured as 24-h urine excretion) and urine potassium:sodium ratio showed a significant relation (with fasting calcium excretion). CONCLUSIONS: We did not find that the first void urine pH by paper strip measurement provided an index of daily net endogenous acid production as reflected in 24-h NAE. In our sample of young adults, daily sodium intake positively correlated with bone resorption, as reflected in fasting urine calcium, whereas daily NAE did not.

Adult↗

PubMed1997

Teaching three-dimensional surgical concepts of inguinal hernia in a time-effective manner using a two-dimensional paper-cut.

BACKGROUND: Because inguinal hernia repair is difficult for third-year students to comprehend, a 2-dimensional paper-cut was developed to teach the concepts of inguinal hernia in a time-effective manner before students' observation of herniorrhaphy in the operating room. METHODS: Using Adobe Illustrator 5.5 for MacIntosh, a 2-dimensional inexpensively printed paper-cut was created to allow students to perform their own simulated hernia repair before observing surgery. The exercise was performed using a no.15 scalpel or an iris scissors and was evaluated by comparing 10-question pre-tests and post-tests. RESULTS: Seventy-five students performed the exercise, most completing it within 15 minutes. The mean pre-test score was 7.4/10 and the mean post-test score was 9.1/10. Students performing the paper-cut reported better understanding when observing actual herniorrhaphy. CONCLUSIONS: A 2-dimensional paper-cut ("surgical origami") may be a time-effective method to prepare students for the observation of hernia repair.

General Surgery↗

PubMedDate not supplied

Use of a paper-strip absorption method to measure the depth and volume of saliva retained in embrasures and occlusal fussae of the human dentition.

Embrasures and occlusal fossae are regions of the human dentition that readily retain saliva, as well as dental plaque and dietary substrates. In this study, a wax filling and weighing technique was used to determine the volumes of these irregularly shaped spaces, and a paper-strip absorption method was developed for measuring the thickness and amounts of saliva therein. The volumes were measured on dental stone models prepared from alginate impressions of the maxillary arches of each of eight individuals and on an acrylic maxillary denture representative of the shape and alignment of normal-sized adult teeth. Embrasure volumes in the two cases were similar and ranged between 4.0 and 16.4 microliters for the individual participants, and between 4.8 and 14.9 microliters for the denture. Occlusal fossae volumes of posterior teeth determined on the denture ranged between 6.0 and 9.8 microliters. The paper-strip absorption method for the thickness or amount of saliva in embrasures or fossae consisted of the absorption of the saliva in these sites on to filter-paper strips and the measurement of the collected volumes electronically with a Periotron 6000 micro-moisture meter. Residual saliva for the embrasures between the two central incisors and the second premolar and first molar ranged between 0.12 and 0.56 with means of 0.28 and 0.37 microliter, respectively, for the same eight participants. Corresponding saliva Vmax volumes were 0.48 and 0.63 microliter, respectively. Further paper strip absorption measurements of saliva in embrasures and fossae showed a linear relation between Periopaper dipstick values and embrasure saliva volumes when these were less than 1 microliter. This range includes most residual saliva volumes normally found in these sites in vivo. For volumes of saliva greater than 1 microliter, small increments in dipstick values in embrasures corresponded to very large changes in total embrasure volumes, which reflects their exponential widening beyond about that point. For saliva thickness measurements, a blue food dye was used to construct a standard curve relating depth of saliva in embrasures and fossae (measured with an electronic micrometer) to Periopaper dipstick scores (measured with the Periotron). The relation was linear for both sites, with r values of 0.98 and 0.99, respectively (p < 0.001 for each), and was used to convert extensive in vivo depth measurements of embrasures and fossae determined in microlitres by the dipstick method in an earlier study to thicknesses in millimetres here. In the earlier study, residual saliva on oral mucosal and smooth dentition surfaces was quantified by the blotting method. Together with the method developed here, it should now be possible to measure the saliva, residual or otherwise, on all oral surfaces whether uniform or irregular in shape.

Adsorption↗

PubMed1970

Studies of electric capacitance of membranes. I. A model membrane composed of a filter paper and a lipid analogue.

A hydrophobic filter paper of a given pore size containing a synthetic lipid, i.e. dioleyl phosphate, was interposed between aqueous electrolyte solutions having the same chemical composition and temperature. The electric capacitance and conductance of the membrane immersed in various concentrations of KCl were measured in the frequency range from 20 to 3 x 10(6) cycle/sec. The observed capacitance and conductance were found to be strongly dependent on the applied frequency. A theory is proposed to account for this dispersion of impedance observed in the present membrane-electrolyte system. The dispersion is attributed to the formation of bilayer membranes of the lipid inside the filter paper. The effects of the salt concentration, the adsorbed quantity of the lipid, and the pore size of the filter paper on the capacitance and conductance of the membrane are discussed in terms of the distribution function of bilayers formed within the filter paper.

Electric Conductivity↗

PubMed2000

Determination of soluble anions and cations from waters of pulp and paper mills with on-line coupled capillary electrophoresis.

When the degree of closure of the paper machine wet end waters increases, wet end problems also become more difficult to control without specific and selective on-line measurements. The need to measure the concentrations of individual compounds in order to explain wet end phenomena is growing. This study was performed to set up a CE system to a paper machine and to determine soluble inorganic and organic ions in different locations of pulp and paper process waters with real time analyses by two on-line CE methods. A reconstructed commercial CE apparatus was connected to a papermaking machine via an apparatus, which was a combined sampling and sample pretreatment instrument, the role of which was to filter and dilute the samples before on-line determination by CE. The on-line procedures were optimized for simultaneous determination of anions as chloride, sulfate, oxalate, formate and acetate and for determination of cations as potassium, calcium, sodium, magnesium and traces of aluminium. The quantification was performed with external standard methods using the programs available in the commercial CE instrument. The concentrations of the ions were transferred by using a computerized transfer algorithm exporting the results from the analysis instrument to the process control unit. The developed on-line procedures were tested three times in paper and paperboard mills for 1 month at a time. Correlations were observed between the CE results and changes in the processes.

Anions↗

PubMed2003

Comparison of gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry for the determination of fatty and resin acids in paper mill process waters.

A comparative study of the performance of liquid chromatography (LC)-atmospheric pressure chemical ionisation (APCI)-mass spectrometry (MS) and gas chromatography (GC)-mass spectrometry techniques for the determination of resin and fatty acids from paper mill process waters was carried out. These compounds are responsible for the high toxicity of paper mill effluents and little research has been carried out regarding their analysis using mass spectrometric techniques. To prove the usability of GC and LC-MS, 16 treated and untreated water samples of recycle, kraft and pulp paper mills were analysed and good agreement was observed as regards to compounds detected and corresponding concentrations. This paper also reports the limits of detection, recoveries, reproducibility, linearity and precision using the two methods. GC-MS presented better selectivity and lower detection limits (below 0.2 microg/l), but derivatization of the extracts and the short life of derivatives (12-24 h) made the technique tedious and prone to high variations. Although LC-APCI-MS presented coelution of the non-aromatic resin acids, it also showed good sensitivity (limits of detection <3 microg/l) and permitted the detection of resin and fatty acids at microg/l level. In addition, since samples could be directly injected to the chromatographic system, LC-APCI-MS was proven as a powerful technique for quick and unequivocal quality control during papermaking.

Atmospheric Pressure↗

PubMed2003

The adsorption behavior of p-hydroxybenzoic acid on a silver-coated filter paper by surface enhanced Raman scattering.

On dried filter paper coated with silver nanoparticles, surface-enhanced Raman scattering (SERS) spectra of p-hydroxybenzoic acid (PHBA) were studied, and high-quality SERS spectra were obtained, indicating that the silver-coated filter paper is a highly SERS-active substrate. The analysis showed that the adsorption behavior of PHBA molecules on silver nanoparticles coated on filter paper was different from that in silver aqueous colloids. On the filter paper, it was found that the SERS spectra of PHBA changed with the proportion of PHBA molecules and silver nanoparticles, indicating that the adsorption behavior of PHBA molecules changed with the proportion. The probable reasons are given.

Journal Article↗

PubMed1976

TSH measurements from blood spots on filter paper: a confirmatory screening test for neonatal hypothyroidism.

A sensitive radioimmunoassay for the measurement of TSH in the eluate of blood spotted on filter paper has been developed. The method is consistently sensitive to 0.1 to 0.25 muU of TSH and enables the detection of values equivalent to 6 to 15 muU/ml of serum. The measurement of TSH in the filter paper spot in all infants with low filter paper spot T4 has permitted rapid confirmation of 10 cases of neonatal hypothyroidism. However, cases of hypothalamic hypothyroidism with low or normal filter paper spot TSH concentrations would have been missed using only this method. Since these patients represent approximately 10% of our neonatal hypothyroid population, we do not recommend this method as a primary screening procedure, but rather as a confirmatory test which will accelerate the diagnosis and therefore the onset of therapy.

Filtration↗

PubMedDate not supplied

A filter paper technique for the detection of anti-filarial IgG4 in lymphatic filariasis.

In a previous study performed in south Sulawesi (Sulawesi Selatan), Indonesia, we established that the immunoglobulin G4 (IgG4) enzyme-linked immunosorbent assay (ELISA) is a suitable community diagnostic method and that it can distinguish areas of high and low prevalences within short distances. In an attempt to make this diagnostic tool more applicable in the field, a comparative study using serum and blood collected on filter paper was undertaken with 568 individuals living in 2 areas with different endemicity for brugian filariasis in south Sulawesi. In Mamuju district, where the microfilaria (mf) prevalence of the studied individuals was 18.4%, antifilarial IgG4 was present in 73.1% of the venepuncture samples and 72.5% of the filter paper samples, respectively. In Mangkutane district, where lymphatic filariasis is transmitted at a low level (mf rate 2.4%), antifilarial IgG4 was detected in 35.5% and 39.9% of similar samples, respectively. There was no significant difference in the IgG4 detection rate determined from venepuncture and filter paper samples from the same donors (P = 0.124), and the IgG4 values were highly correlated (p = 0.97, P < 0.001, n = 568). These results indicate that the filter paper technique for collection of blood samples is a suitable alternative to venepuncture for use in the IgG4 ELISA.

Adolescent↗

PubMedDate not supplied

Detection of anti-Leishmania antibodies in blood collected on filter paper by the direct agglutination test.

Human capillary blood drawn by finger pricking was absorbed on Whatman no. 4 filter paper and tested for anti-Leishmania antibodies using the direct agglutination test (DAT). Over 1400 filter paper samples were collected from L. infantum endemic areas in northern Pakistan and compared with 569 serum samples obtained from the same area. Eleven filter paper samples (0.8%) gave positive results (antibody titre > or = 1:3200), compared with 8 serum samples (1.4%); the difference was not statistically significant (P = 0.35). The filter paper eluates compared well with their homologous sera, and were strongly correlated with respect to antibody titre (r = 0.7, P < 0.0001).

Adolescent↗

PubMed2002

On the verification of the applicability of the orthotropic plate wave theory to paper.

In the literature one basic work can be found that describes an attempt to verify the applicability of the orthotropic plate wave theory to paper. In the present study we have repeated the key experiment and also modified the original experimental set-up to be able to make new complementary measurements. The performed verification attempt is based on a key experiment in which an ultrasonic resonance method is used. When it is applied to paper, a second resonance can be observed in addition to the one that originates from the asymmetric A0 mode. The result of the verification experiment is conclusive only if the source of this second resonance is the symmetric S0 mode. Our results show that the second resonance is not generated by the S0 mode. Instead, they indicate that the source is a longitudinal wave propagating in the thickness direction of the paper. We therefore conclude that the applicability of the orthotropic plate wave theory to paper cannot be verified by performing the key experiment that is described in the literature.

Journal Article↗

PubMed2001

Usefulness of blood and urine samples collected on filter paper in detecting cytomegalovirus by the polymerase chain reaction technique.

A rapid test for the diagnosis of congenital CMV infection is still needed. This study evaluated the usefulness of dried blood and urine samples collected on filter paper for detecting cytomegalovirus (CMV) by the polymerase chain reaction (PCR) assay compared with the use of liquid urine. Samples were obtained from 332 infants aged 1-7 days. Liquid urine samples were collected into bags, cultured in human fibroblasts, and processed using a multiplex PCR technique. Dried urine samples were obtained by placing a piece of filter paper in contact with the infant's genitals. The heels of neonates were punctured and capillary blood was blotted onto filter paper and dried. Dried blood and urine specimens were analyzed by multiplex PCR and nested-PCR assays. A diagnosis of congenital CMV infection was established by isolating the virus, and by detecting viral DNA in the liquid urine. Of the 332 liquid urine samples collected from 332 neonates, seven (2.1%) were positive for CMV and 325 were negative, by both cell culture and PCR assay. In dried samples, CMV DNA was detectable only with a nested PCR assay. Compared with known CMV infection status, 5/7 (71.4%) neonates were positive for congenital CMV infection using dried blood samples. All 325 uninfected neonates were negative. In the dried urine samples, 4/4 CMV-infected infants gave positive tests, and all 262 uninfected infants were negative. Although further improvements in sample collection and/or processing are still needed, PCR testing on dried urine or blood collected on filter paper is a promising approach in the diagnosis of neonatal CMV infection.

Blood Specimen Collection↗

PubMed2005

Nanoparticles of Mg(OH)2: synthesis and application to paper conservation.

We report an investigation on the effects of counterions of magnesium salts on the homogeneous phase precipitation reaction to yield nanoparticles. The results provide new parameters to guide the control of the size, monodispersity, crystallinity, and morphology of Mg(OH)(2) nanoparticles. Evidence emerged that magnesium counterions affect the size of crystallites. The particle size increases from about 50 to 200 nm and follows the Hofmeister anion series: sulfate < chloride < nitrate </= perchlorate. All of the results show that a proper choice of counterion and composition of reaction mixture allows one to modulate and set conditions that predetermine production of nanoparticles with desired size. The Mg(OH)(2) nanoparticles have been applied to the successful conservation of paper. To demonstrate the efficacy of nanoparticles as deacidifying agent and as protection against cellulose aging, some samples of paper from the 18th century were treated with the nanoparticles and artificially aged by subjecting them to hydrothermal and photooxidative degradation. The treatment with nanoparticles preserved the mechanical features of paper, and the deterioration was consistently reduced. The comparison with the Wei t'O method (based on magnesium alkoxides), one of the most common and largely used methods for paper deacidification, indicates the following: (1) nanoparticles present a higher efficacy in the deacidification treatment since they are much more reactive; (2) nanoparticles are less aggressive since they are easily converted into the carbonate form; (3) they present minor disadvantages related to the chemical nature of the solvent used in the Wei t'O (i.e., CFC); (4) papers/books can be treated with very simple procedures, and do not require any special apparatus; (5) nanoparticle treatments have substantial economic benefits.

Journal Article↗

PubMed2001

Everyday life and legal values: a concept paper.

This "concept paper" emerged from a Law and Human Behavior (LHB) Workshop, that was called by the journal's Editor, Richard Wiener, and held at St. Louis University on March 19-21, 1999. This workshop, which brought together 22 scholars and researchers in legal psychology, was part of James Ogloff's Presidential Initiative Project for the American Psychology/Law Society, and was supported by St. Louis University and an NSF grant. Prior to our arrival, each participant answered queries from the Editor about LHB and the field of psychology and law, and each was asked to offer five topics that were underrepresented in the journal or that we would like to see addressed in future issues. At the workshop, we were assigned to small groups, and the authors of this paper constituted one such group. The "charge" for all groups was to "develop plans for encouraging submissions in areas of psycholegal scholarship that continue to be infrequent topics of investigation," and then to develop a concept paper. The direction our group took is captured by our title, "Everyday Life and Legal Values," and within this paper we explicate the topic, identify a number of underrepresented research areas, suggest some research paradigms for investigating them, and present this within a "perspectival directions" frame that ties established lines of research to the newer ones we propose.

Humans↗