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At least 1,117 records · Page 62Linked to original sources
PubMed2006

Preparation of cross-linked cellulases and their application for the enzymatic production of glucose from municipal paper wastes.

Hydrolysis of cellulosic wastes has been applied for environmental purposes and glucose production. An enzymatic process is proposed for such treatment of municipal cellulosic wastes, and the optimum conditions are described. It was found that different conditions should be applied for the treatment of soft or hard paper wastes, the most characteristic being pretreatment of wastes and temperature of the treatment process. Optimization of enzyme characteristics was also examined after stabilization of the enzymes by cross-linking. Endocellulase was better stabilized after cross-linking with EDAC whereas, exocellulase was better with glutaraldehyde. The application of cross-linked enzyme in the waste paper treatment process resulted in about a 25% increase of glucose liberation.

Buffers↗
PubMed2005

Effects of maternal versus direct exposure to pulp and paper mill effluent on rainbow trout early life stages.

The acute and chronic effects of secondary-treated effluent from a New Zealand pulp and paper mill were assessed using both long-term adult and early life stage (ELS) laboratory exposures of rainbow trout. The relative impact of maternal exposure versus ELS exposure was assessed by a comparison of directly exposed eggs and larvae with the eggs and larvae of exposed adult trout that were reared in reference water. Rainbow trout were exposed to a secondary-treated mixed thermomechanical/bleached kraft mill effluent at a concentration of 15% or to reference water from the egg through to 320-d-old juveniles. The 2 adult rainbow trout exposures were undertaken with nominal concentrations of 10% and 12% treated effluent, respectively. There was no marked effect of water hardening with 15% effluent on fertility or survival of eggs to 16 d. In a subsequent exposure (with hardening in reference water), no significant effects were found on mortality to hatch, time to hatch, length at hatch, mortality to swim-up, mortality to 320 d, or deformity rate at hatch. At experimental termination (320 d), direct-exposed juveniles had smaller livers and reduced condition factor, likely due to differences in food consumption. In 2 subsequent consecutive experiments, exposure of adult trout to 10% and 12% effluent for 2 mo, followed by incubation of the fertilized eggs in reference water, produced no impact on fertility, survival to hatch, survival to swim-up, or length and weight of fry at swim-up. Exposure of adult trout to 12% treated effluent for 8 mo prior to egg fertilization also did not result in differing rates of fertility, mortality to hatch or mortality to swim-up. However, the 8-mo maternal exposure did result in swim-up fry that were significantly shorter and weighed less than the reference swim-up fry. This difference was directly attributable to smaller eggs in the 8-mo-exposed female trout. These results demonstrate that this pulp and paper mill effluent is more likely to elicit indirect impacts on progeny size through chronic exposure of adults to effluent during gonadal recrudescence rather than through direct exposure of early life stages to effluent.

Animals↗
PubMed1990

Evaluation of occupational exposure to sulfur compounds in paper pulp kraft mills.

A study was carried out to provide a comprehensive profile of sulfur gas concentrations to which workers are exposed during the manufacture of paper pulp by the kraft process. Methods currently available--including colorimetric tubes, direct-reading monitors, and gas chromatographic methods--were compared. Gas chromatography is the only technique able to reliably measure individual sulfur gases. However, the necessity of using a gas sampling bag renders this technique inappropriate for personal monitoring. A strategy to evaluate occupational exposure was developed, based on fluctuations in workplace concentrations and the time profile of worker activities. In most samples, only three sulfur products were detected: dimethyl sulfide, methyl mercaptan, and hydrogen sulfide. Concentrations varied as a function of time and location and are correlated to process and equipment-operation variables. Using the proposed strategy, it was demonstrated that workers in the pulp and paper industry can be exposed to significant concentrations of sulfur compounds.

Chromatography, Gas↗
PubMed1992

Evaluation of OSHA method 5 for measuring chloroform in pulp and paper industry workplace and ambient atmospheres.

As a result of the recent lowering of the Occupational Safety and Health Administration's (OSHA's) permissible exposure limit (PEL) for chloroform from 50 ppm to 2 ppm, interest has increased in measuring chloroform in pulp and paper industry workplace atmospheres. OSHA suggested that its Method 5 should be used for measuring chloroform concentrations in the range of the new PEL. There are some potential problems with using Method 5 for this purpose. Pulp and paper industry atmospheres may interfere with the measurement because of high temperature, high humidity, and the presence of chlorine. The charcoal sorbent tubes specified in OSHA Method 5 were challenged in the laboratory with a test gas containing 0.1, 0.5, 1, and 2 times the PEL of chloroform at 38 degrees C with 80% to 93% relative humidity and ca. 0.5 ppm chlorine. Application of the National Institute for Occupational Safety and Health (NIOSH) validation protocol to the results indicated a bias of -8.2% and a pooled coefficient of variation (CV) of 0.0274. The method CV is less than the critical CV; thus, the method is acceptable by the NIOSH validation protocol under these conditions. Field testing of OSHA Method 5 was successful and did not reveal any unexpected problems. Additional tests showed that with some modification, OSHA Method 5 can be used to measure chloroform concentrations in ambient atmospheres down to 0.1 ppb.

Air Pollutants, Occupational↗
PubMed1994

Electric and magnetic fields at three pulp and paper mills.

Extremely low frequency (60 Hz) electric and magnetic field levels were measured at three Canadian pulp and paper mills, using area point-in-time measurements. Most electric field levels were below the limit of detection of 1 V/m (92 of 132 measurements); the highest measured field was 47 V/m. Measured magnetic field strengths ranged from less than the limit of detection (0.125 mG, 2 of 132 measurements) to 706 mG, with a median of 1.6 mG. Magnetic field levels were higher in mills that consume more electric power, but worker exposures could not be predicted according to plant power consumption. Overall, electric and magnetic field levels in the three pulp and paper mills were similar to those experienced by the general population. However, maximum magnetic field intensities in some areas were as high as those experienced by electrical workers.

British Columbia↗
PubMed2004

Removal of residual COD in biologically treated paper-mill effluent and degradation of lignin using nonthermal plasma unit.

This manuscript focused on the degradation behavior of lignin and the reduction of residual COD in the biologically treated paper-mill effluent by means of ionized gas from nonthermal plasma unit. The removal efficiencies of COD, lignin, and color after treated with ionized gas were over 95, 93, and 97%, respectively. It has been found that the degradation of aromatic ring has been proved by FTIR, 1H NMR and UV spectra. The degradation of lignin through ionized gas was accompanied with the increase of SO4(2-) and the decrease in pH. The results show that the residual COD in the biologically treated paper-mill effluent contains NBD matter with aromatic ring compounds. Also NBD organic matter such as aromatic ring in effluent treated with ionized gas was degraded. The residual COD declined by 60% at the ionized gas flow rate 5 L/min and HRT 30 min.

Biodegradation, Environmental↗
PubMed2005

A-role of alkaline elements in formation of PCDDs, PCDFs, and coplanar PCBs during combustion of various paper samples.

Combustion of industrial and domestic wastes produces significant amounts of dioxins (PCDDs, PCDFs, and coplanar PCBs). These wastes contain numerous kinds of materials, including inorganic elements, which may play an important role in dioxin formation upon combustion. Six paper samples--impregnated with NaHCO3, NaCl + fly ash, polyvinyl chloride (PVC), and PVC + NaHCO3--were combusted in a well-controlled incinerator at 512-760 degrees C and exhaust gases were analyzed for dioxins (PCDDs, PCDFs, and coplanar PCBs). Addition of fly ash, which contained high levels of Ca and Cl, to NaCl impregnated-newspaper increased total dioxin formation from 80.8 ngg(-1) to 139 ngg(-1) during combustion. Addition of NaHCO3 to PVC-impregnated newspaper increased total dioxin formation from 220 ngg(-1) to 288 ngg(-1). Formation of PCDDs from NaHCO3/PVC-impregnated newspaper were significantly less than that from newspaper impregnated with PVC alone. On the other hand, more PCDFs formed from NaHCO3/PVC-impregnated newspaper than from newspaper impregnated with PVC alone. Addition of NaHCO3 to a PVC-impregnated newspaper changed the production pattern of dioxins. PVC- impregnated newspaper produced the greatest amount of coplanar PCBs (12.3 ngg(-1)), which may be accounted for by the relatively high level of TEQ value (3.31 ng-TEQg(-1)) of this sample. Generally, addition of fly ash and alkali metals, such as Na, to paper samples increased the total dioxin formation in exhaust gases during combustion. The results suggest that alkali metals increase Cl concentrations at a reaction site by trapping chloride ions and/or chloride radicals and consequently increasing dioxin formation.

Air Pollutants↗
PubMed1987

Development and evaluation of a simplified method to collect blood samples to determine hemoglobin and hematocrit using chromatographic paper discs.

A simplified method for the simultaneous determination of hemoglobin and hematocrit using dried capillary blood collected on chromatographic paper discs was developed and evaluated under laboratory and field conditions. The paper disc method (PDM) was compared with traditional laboratory methods (TM) in blood samples collected from human subjects with a wide range of hemoglobin and hematocrit values. Associations between PDM and TM were highly significant (p less than 0.001). Correlation coefficients were 0.90454 for hemoglobin and 0.9266 for hematocrit and there were no significant differences between mean values obtained by both procedures. Hemoglobin levels in discs remained unchanged during a storage for 1 mo. Hematocrit values, however, were constant throughout a 6-mo evaluation. On average, the percent coefficients of variation were 3.4 and 8.3% for determinations of hemoglobin and hematocrit, respectively. It is concluded that PDM represents a practical alternative approach for assessing hematological status in the field.

Adult↗
PubMed1999

Screening of folate status with use of dried blood spots on filter paper.

BACKGROUND: Dried blood spots (DBS) on filter paper have been a successful and economical matrix for neonatal screening. OBJECTIVE: Our objective was to develop and evaluate an optimized method for DBS folate analysis and to assess DBS folate stability. DESIGN: DBS were eluted from paper by sonication in 5 g ascorbic acid/L containing 0.1% (by vol) Triton X-100 and hemoglobin folate values (HF; as pmol/g) were calculated from DBS eluate folate and hemoglobin concentrations. RESULTS: Over 95% of DBS folate was eluted during a standardized sonication cycle and DBS folate assay reproducibility was acceptable both within (CV: <8%) and between (CV: <9%) runs. HF means (+/-1 SD) from finger-stick DBS and conventional venous methods were 2513 +/- 1144 and 2607 +/- 1195 pmol/g, respectively, in blood samples taken concurrently from 80 donors, and they correlated well (r = 0.97, P < 0.001). HF values and erythrocyte folate measures may be interconverted by using the mean cell hemoglobin concentration. CONCLUSION: The DBS matrix has potential as an inexpensive and practical option for folate screening studies.

Blood Stains↗
PubMedDate not supplied

A tribute to toilet paper.

In modern use, toilet paper would seem to play an important role as a barrier to the transmission of enteric infection by the fecal-manual-oral route. A historical review reveals a dearth of information on this topic. The remarkable compliance with the hygienic practice of toilet paper use is in contrast to the more limited compliance with hand-washing policies touted universally as a sound infection-control measure.

Bacterial Infections↗
PubMed1982

Diazotizable arylamine cellulose papers for the coupling and hybridization of nucleic acids.

We describe the synthesis of a family of arylamine-substituted papers which can be diazotized and coupled with nucleic acids. The synthesis is simple and uses readily obtainable starting materials. A partial characterization of the nucleic acid binding activity is reported, as well as a demonstration of the utility of the activated paper for the detection of electrophoretically separated RNA by blot transfer and hybridization.

Cellulose↗
PubMed1979

Identification of procollagen mRNAs transferred to diazobenzyloxymethyl paper from formaldehyde agarose gels.

Poly A containing RNA isolated from embryonic chick calvaria was transferred from 6% formaldehyde 0.75% agarose gels to diazobenzyloxymethyl paper and the paper then hybridized to either nick translated pro alpha 1 collagen cDNA clones, pCg1 or pCg54, or to the nick translated pro alpha 2 collagen cDNA clone, pCg45. From the mobilities of the bands hybridizing most strongly to each, pro alpha 2 collagen mRNA was shown to be slightly larger than pro alpha 1 mRNA; they are 5100 and 4900 nucleotides long respectively. pCg54 also hybridized weakly to two bands of lower mobility, corresponding to RNAs 6.4 and 5.6 kb long. Neither pCg54 nor pCg45 hybridized to type II procollagen mRNA in poly A containing RNA isolated from embryonic chick sterna.

Animals↗
PubMed1980

Isolation of DNA from agarose gels using DEAE-paper. Application to restriction site mapping of adenovirus type 16 DNA.

A new method for isolating DNA from agarose gels is described. The method involves the simultaneous transfer of all DNA-fragments from an agarose slab gel onto DEAE-cellulose paper and the elution of the individual fragments from the paper with 1 M NaCl. DNA isolated from agarose gels in this way is susceptible to cleavage with several restriction endonucleases, and can be labeled in vitro with E coli DNA-polymerase I, T4 DNA-polymerase and T4 polynucleotide kinase. We have used the method to construct restriction endonuclease maps of adenovirus type 16 DNA.

Adenoviridae↗
PubMed1997

Cohort mortality study of pulp and paper mill workers in British Columbia, Canada.

The authors studied a cohort of 30,157 male pulp and paper workers in British Columbia, Canada. Of these, 20,373 worked in kraft mills only, 5,249 in sulfite mills only, and 4,535 in both kraft and sulfite mills. All workers with at least 1 year of employment on January 1, 1950, or thereafter until December 31, 1992, were studied. Standardized mortality ratios (SMRs) were used to compare the mortality rates of the cohort with those of the Canadian male population. Ninety percent confidence intervals (CIs) for the SMRs were obtained. Cancer risks significantly associated with work duration and time from first employment of 15 years or more were observed: 1) total cohort: pleura (SMR = 3.61, 90% CI 1.42-7.58); kidney (SMR = 1.69, 90% CI 1.13-2.43); brain (SMR = 1.51, 90% CI 1.03-2.16); 2) workers in kraft mills only: kidney (SMR = 1.92, 90% CI 1.04-3.26); 3) workers in sulfite mills only: Hodgkin's disease (SMR = 4.79, 90% CI 1.29-12.37); 4) workers ever employed in both kraft and sulfite mills: esophagus (SMR = 1.91, 90% CI 1.00-3.33). These malignancies have been associated with the following known or suspected carcinogens to which pulp and paper workers may have been exposed: asbestos (pleura), biocides (kidney), formaldehyde (kidney, brain, Hodgkin's disease), hypochlorite (esophagus). A nested case-control study with detailed exposure assessment is under way to help determine whether excess risks for specific cancers reflect exposure among subsets of workers.

British Columbia↗
PubMed2003

Androstenedione and progesterone in the sediment of a river receiving paper mill effluent.

The Fenholloway River near Perry, Florida, receives effluent from a paper mill and contains populations of masculinized female eastern mosquitofish, Gambusia holbrooki. A previous study identified the androgen precursor androstenedione at a low concentration (0.14 nM) in water samples from the river. The present study makes use of a toxicity identification and evaluation approach that includes solid phase extraction and high pressure liquid chromatography purification, androgen receptor transcription assays, and liquid chromatography mass spectroscopy to identify and characterize steroids in the Fenholloway River sediment. Androstenedione (2.4 nM) and progesterone (155 nM) were identified in the river sediment at concentrations greater than in the river water column (0.14 nM androstenedione, and 6.5 nM progesterone). Spring Creek, a comparison stream that does not receive mill effluent, contained low levels of progesterone (0.3 nM) but no androstenedione in the sediment. The data are consistent with the hypothesis that pine pulp-derived phytosteroids in the paper mill effluent accumulate in river sediment where they are converted by microbes into progesterone and this into androstenedione and other bioactive steroids. Equally important is that normal streams with much less organic matter still contain progesterone, but at dramatically lower levels. The presence of androgens and androgen precursors in the river water and sediment likely contributes to the masculinized phenotype of the female Gambusia holbrooki in the Fenholloway River.

Androstenedione↗
PubMed2003

Results of surveys at United States pulp and paper mills for the presence of scales and precipitates containing naturally occurring radioactive material (NORM).

Field surveys were carried out at sixteen pulp and paper mills in the United States--seven kraft process, two sulfite process, and seven recycling process mills--for the presence of naturally occurring radioactive material (NORM) in precipitates and scales. NORM was detected at three of the kraft mills, one sulfite mill, and none of the recycling mills. At one of the kraft mills, the NORM was associated with a commercial aluminum sulfate ("alum") slurry used on the paper machines and in intake water treatment. The maximum activity level of this alum scale was 252,000 Bq kg(-1) (6,800 pCi g(-1)) 228Ra. At two kraft mills, NORM was associated with precipitates in the bleach plant. The measured NORM activity in samples of these scales was approximately 44,400 Bq kg(-1) (1,200 pCi g(-1)) 226Ra. Where NORM was detected at a sulfite mill, the NORM deposits were found adhering tightly to the surfaces of brownstock washers. Although samples were not removed for radionuclide analysis, survey readings at the drum surface were 26 nC kg(-1) h(-1) (100 microR h(-1)) with a scintillation counter and 2,200 cpm with a Geiger-Muller counter. At all mills, exposure rate measurements and risk assessment calculations indicated that it would be highly unlikely for any worker's annual exposure to exceed 1 mSv (100 mrem) (the Nuclear Regulatory Commission limit for untrained workers) due to exposure to these materials.

Background Radiation↗
PubMed1985

Analog image recording using a laser printer and paper system.

This article describes a method for generating gray scale analog hard copy images on ordinary paper using a laser printer system. Operation of the computer-controlled laser printer is described. The cost of the laser printer/paper technology is estimated and compared with the cost of multiformat camera/conventional film systems. Results of an initial clinical evaluation of laser printed paper images are presented.

Angiography↗
PubMed1985

Paper bezoar in the stomach.

A toilet paper bezoar caused acute abdominal distention and symptoms of an acute condition of the abdomen in a 5-year-old boy. Simple gastrotomy served to clear the paper bezoar and relieve the gastric obstruction after nonoperative methods failed.

Bezoars↗