bluuebunny/crossref_metadata_2025 huggingface dataset:
Can an Alternative Umbilical Arterial Catheter Solution and Flush Regimen Decrease Iatrogenic Hemolysis While Enhancing Nutrition? A Double-Blind, Randomized, Clinical Trial Comparing an Isotonic Amino Acid With a Hypotonic Salt Infusion
Authors: Jackson Jodi K. , Biondo Deborah J. , Jones Janice M. , Moor Pamala J. , Simon Stephen D. , Hall Robert T. , Kilbride Howard W.
Published: August 2004

Objective. In the process of sampling blood through an umbilical arterial catheter (UAC), infant blood comes into stagnant contact with infusion solution in the “waste syringe” before being reinfused. We have previously demonstrated in vitro that this process is associated with less hemolysis of red blood cells (RBCs) with use of an isotonic solution compared with a hypotonic 0.25 normal saline (NS) solution. The objective of this study was to compare the in vivo effect on hemolysis of 2 UAC infusion/flush regimens (an isotonic regimen vs a hypotonic regimen) and to assess the early nutritional benefit of an amino acid solution as the isotonic UAC infusion solution.

Methods. Infants who had a birth weight of ≤1.5 kg and were expected to have a UAC for ≥3 days were enrolled within 24 hours of life into this prospective, double-blind, randomized, clinical trial of 2 UAC infusion solution/flush regimens. Power analysis demonstrated that 40 infants were needed to determine differences in hemolysis quantified by plasma-free hemoglobin (PFH) level. Nutrition from glucose was evaluated by measurement of daily dextrose calories. C-peptide was measured to evaluate endogenous insulin production. Adverse events and protein tolerance were tracked.

Results. Twenty-two infants (mean gestational age: 27 weeks; 945 g birth weight) were enrolled in each group, for an average of 4.2 days (range: 2.5-8 days). There were no group differences in demographics. PFH levels were lower for infants who received isotonic amino acid (IAA) in comparison with 0.25 NS (33 ± 14 mg/dL vs 62 ± 27 mg/dL, respectively). C-peptide was higher in those who received IAA, as were nonprotein calories received on days 4 to 6 of the study (51 ± 11 kcal/kg/day vs 44 ± 12 kcal/kg/day, IAA vs 0.25 NS, respectively).

Conclusions. Lower PFH levels in IAA versus 0.25 NS group were consistent with our hypothesis of decreased hemolysis with an isotonic infusion/flush regimen. IAA use may also allow greater early glucose nutrition, as indicated by the higher level of endogenous insulin production and improved glucose tolerance. IAA seems to be a superior UAC solution to 0.25 NS in that it is associated with less hemolysis and improved nutrition.
Terminal 22q Deletion Syndrome: A Newly Recognized Cause of Speech and Language Disability in the Autism Spectrum
Authors: Manning Melanie A. , Cassidy Suzanne B. , Clericuzio Carol , Cherry Athena M. , Schwartz Stuart , Hudgins Louanne , Enns Gregory M. , Hoyme H. Eugene
Published: August 2004

Objective. Cryptic subtelomeric chromosome rearrangements account for 6% to 10% of idiopathic mental retardation. As cytogenetic and molecular techniques have become more sophisticated, the number of genetic syndromes attributed to these microdeletions has increased. To date, 64 patients have been described in the literature with a more recently recognized microdeletion syndrome, del 22q13.3. The purpose of this study is to present 11 new cases of this recently described syndrome to delineate further the phenotype and to alert the clinician to another genetic condition that should be considered in the differential diagnosis of early hypotonia, delayed speech acquisition, and autistic behavior.

Methods. Eleven patients were evaluated in 3 academic institutions. Clinical features and results of cytogenetic testing were recorded and tabulated. Reasons for referral for genetic evaluation included developmental delay, severe expressive speech and language delay, and dysmorphic features.

Results. Age of presentation ranged from 5 months to 46 years. There were 10 female patients and 1 male patient. All of the patients exhibited delayed motor development, some degree of hypotonia, and severe expressive speech and language delay. Dysmorphic facial features included epicanthal folds, large cupped ears, underdeveloped philtrum, loss of cupid's bow, and full supraorbital ridges. Six patients exhibited autistic-like behaviors. Microscopically visible chromosome deletions were observed in 6 patients. In the remainder, the deletion was detected with the use of fluorescence in situ hybridization.

Conclusions. Hypotonia and developmental delay are nonspecific findings observed in many malformation and genetic syndromes. However, in association with severe speech and language delay and autistic-like behavior, this phenotype may be a significant indication to consider the 22q13 deletion syndrome as a potential cause.
Reduced Bone Density Among Children With Severe Hemophilia
Authors: Barnes Chris , Wong Patricia , Egan Brendan , Speller Tessa , Cameron Fergus , Jones Graeme , Ekert Henry , Monagle Paul
Published: August 2004

Objective. Children with severe hemophilia are at risk for reduced bone mineral density (BMD) because of reduced weight-bearing exercise and hepatitis C infection. Reduced bone density in childhood is a risk factor for osteoporosis in later life.

Study Design. We performed a cross-sectional survey of bone density among 19 children with severe hemophilia, at the Royal Children’s Hospital. Results were correlated with findings of blinded objective evaluations of the joints of the lower limb and with hepatitis C status.

Results. The mean lumbar bone mineral apparent density for patients was reduced (0.102 g/cm3), compared with that for control subjects (0.113 g/cm3). The mean areal BMD z score was −0.92, which was significantly reduced, compared with that for control subjects. The difference in bone density was independent of body size. There was a statistically significant relationship between the lumbar BMD z scores and the maximal single joint evaluation scores, but there was no difference based on hepatitis C status.

Conclusions. Our results suggest that children with severe hemophilia have reduced BMD. Patients at risk are those with signs of hemophilic arthropathy. Because osteoporosis may complicate the future treatment of patients with hemophilia, screening of young patients for reduced bone density is recommended.
Association Between Patterns of Maternal Substance Use and Infant Birth Weight, Length, and Head Circumference
Authors: Shankaran Seetha , Das Abhik , Bauer Charles R. , Bada Henrietta S. , Lester Barry , Wright Linda L. , Smeriglio Vincent
Published: August 2004

Objective. To determine the effects of patterns of drug use during term pregnancy on infant growth parameters at birth.

Methods. Histories of cocaine, opiate, alcohol, tobacco, and marijuana use during the 3-month period before pregnancy and the 3 trimesters of pregnancy were recorded at the infants’ 1-month visit. Patterns of use were categorized as consistently high, moderate, or low/none or increasing/decreasing, and effects on growth parameters were analyzed in multivariate linear regression analyses, with adjustment for clinical site, maternal age, prepregnancy weight, multidrug use, and socioeconomic status.

Results. A total of 241 cocaine-exposed women and 410 non–cocaine-exposed women participated in the study. In the cocaine-exposed group, 75% used alcohol, 90% used tobacco, and 53% used marijuana; in the non–cocaine-exposed group, 57% used alcohol, 34% used tobacco, and 19% used marijuana. Birth weight, birth length, and head circumference were significantly greater among infants born to women who used no drugs, compared with women with any cocaine, opiate, alcohol, tobacco, or marijuana use, and were greater among infants born to cocaine nonusers, compared with cocaine users. With adjustment for confounders, birth weight was significantly affected by cocaine (deficit of 250 g with consistently low pattern) and tobacco (deficits of 232 g with consistently high pattern, 173 g with consistently moderate pattern, 153 g with decreasing pattern, and 103 g with consistently low pattern). Head size was affected by cocaine (deficit of 0.98 cm with consistently moderate pattern) and tobacco (deficits of 0.72 cm with consistently high pattern and 0.89 cm with consistently moderate pattern). Birth length was affected by tobacco use only (deficits of 0.82 cm with consistently high pattern and 0.98 cm with decreasing use).

Conclusion. Patterns of tobacco use during pregnancy affect birth weight, length, and head circumference, whereas cocaine affects birth weight and head size, when adjustments are made for confounders, including multidrug use.
Polymorphism of Tumor Necrosis Factor-α and Risk and Severity of Bronchopulmonary Dysplasia Among Very Low Birth Weight Infants
Authors: Kazzi S. Nadya J. , Kim U. Olivia , Quasney Michael W. , Buhimschi Irina
Published: August 2004

Background. Preterm infants with bronchopulmonary dysplasia (BPD) exhibit prolonged elevation of inflammatory indices in their tracheal aspirates. Tumor necrosis factor-α (TNF-α) is a central mediator of the inflammatory response. The adenine-containing alleles of TNF-α−308 and lymphotoxin-α+250 have been associated with increased levels of TNF-α, whereas the adenine allele of TNF-α−238 produces lower levels of TNF-α after stimulation. High levels of TNF-α may promote chronic inflammation by overwhelming counter-regulatory mechanisms and may lead to the development of BPD. Low levels of TNF-α may decrease the risk and/or severity of BPD.

Objective. To determine whether alleles of TNF-α play a role in the susceptibility and/or severity of BPD among very low birth weight infants.

Methods. Infants with birth weights of ≤1250 g were included. Genotypic analyses (polymerase chain reaction-restriction fragment length polymorphism assays) were performed with DNA extracted from whole-blood samples.

Results. Infants who developed BPD (fraction of inspired oxygen at postconceptional age of 36 weeks of >0.21, n = 51) had a younger gestational age (mean ± SD: 27 ± 4 vs 29 ± 2 weeks) and lower birth weight (853 ± 184 vs 997 ± 193 g) than did infants without BPD (n = 69). The genotypic distributions of lymphotoxin-α+250 and TNF-α−308 were comparable among the groups of infants. However, the AA and GA TNF-α−238 genotypes were much less likely to occur among infants with BPD than among infants without BPD. The adenine allele of TNF-α−238 was absent among infants with severe BPD and occurred significantly less often among infants with moderate or severe BPD, compared with infants with mild BPD. The number of adenine alleles of TNF-α−238 was correlated inversely with the severity of BPD (r = −.341).

Conclusion. The adenine allele of TNF-α−238 may reduce the risk and severity of BPD.
Procalcitonin: A Marker of Severity of Acute Pyelonephritis Among Children
Authors: Pecile Paolo , Miorin Elisabetta , Romanello Carla , Falleti Edmondo , Valent Francesca , Giacomuzzi Francesco , Tenore Alfred
Published: August 2004

Objective. Febrile urinary tract infection (UTI) is a common problem among children. The diagnosis and management of acute pyelonephritis is a challenge, particularly during infancy. The distinction between acute pyelonephritis and UTI without renal involvement is very important, because renal infection may cause parenchymal scarring and thus requires more aggressive investigation and follow-up monitoring. However, this distinction is not easy among children, because common clinical findings and laboratory parameters are nonspecific, especially among young children. In an attempt to differentiate acute pyelonephritis from febrile UTI without renal lesions in a group of 100 children, we measured serum levels of procalcitonin (PCT), a new marker of infection. The objective of the study was to determine the accuracy of PCT measurements, compared with C-reactive protein (CRP) measurements, in diagnosing acute renal involvement during febrile UTI and in predicting subsequent scars, as assessed with 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy.

Design. Serum CRP levels, erythrocyte sedimentation rates, leukocyte counts, and PCT levels were measured for 100 children, 1 month to 13 years of age, admitted for suspected febrile UTI (first episode). Renal parenchymal involvement was evaluated with DMSA scintigraphy within 5 days after admission. The DMSA study was repeated 6 months later if the initial results were abnormal.

Results. The mean PCT level was significantly higher in acute pyelonephritis than in UTI without renal lesions (4.48 ± 5.84 ng/mL vs 0.44 ± 0.30 ng/mL). In these 2 groups, the mean CRP levels were 106 ± 68.8 mg/L and 36.4 ± 26 mg/L, mean erythrocyte sedimentation rates were 79.1 ± 33 mm/hour and 58.5 ± 33 mm/hour, and leukocyte counts were 18 492 ± 6839 cells/mm3 and 16 741 ± 5302 cells/mm3, respectively. For the prediction of acute pyelonephritis, the sensitivity and specificity of PCT measurements were 83.3% and 93.6%, respectively; CRP measurements had a sensitivity of 94.4% but a specificity of only 31.9%. Positive and negative predictive values for prediction of renal involvement with PCT measurements were 93.7% and 83% and those with CRP measurements were 61.4% and 83.3%, respectively. When inflammatory markers were correlated with the severity of the renal lesions, as assessed with DMSA scintigraphy, a highly significant correlation with both PCT and CRP levels was found. However, when the 2 parameters were correlated with renal scarring in follow-up scans, a significant positive association was found only for PCT levels.

Conclusions. Serum PCT levels may be a sensitive and specific measure for early diagnosis of acute pyelonephritis and determination of the severity of renal parenchymal involvement. Therefore, this measurement could be useful for the treatment of children with febrile UTIs, allowing prediction of patients at risk of permanent parenchymal renal lesions.
Varicella Zoster Virus Meningitis in a Previously Immunized Child
Authors: Schwab Joel , Ryan Matthew
Published: August 2004

We are reporting a previously well 5-year-old child with varicella-zoster meningitis who had a history of a previous immunization against varicella. This child also developed a transient sensorineural hearing loss. The child was treated with acyclovir and made a full recovery.
Amides, Fatty Acid
Authors: Opsahl Ross
Published: August 2004

Fatty acid amides, which contain a saturated or unsaturated alkyl chain derived from a fatty acid, can be divided into three categories. The first is primary monoamides in which R is a fatty alkyl or alkenyl chain of C5–C23and\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${{\rm{R}}{^{{\prime}}}={\rm{R}}={\rm{H}}}$\end{document}. The second is substituted monoamides, including secondary, tertiary, and alkanolamides in which R is a fatty alkyl or alkenyl chain of C5–C23; R′ and R″ may be a hydrogen, fatty alkyl, aryl, or alkylene oxide condensation groups with at least one alkyl, aryl, or alkylene oxide group. The third category is bisamides where R groups are fatty alkyl or alkenyl chains. R′ and R″ may be hydrogen, fatty alkyl, aryl, or alkylene oxide condensation groups. Primary and secondary amides show strong hydrogen bonding which accounts for their high melting points and low solubilities in most solvents. With tertiary amides (disubstituted amides), hydrogen bonding is not possible, as exhibited by their increased solubility and lower melting points. Many fatty acid amides are essentially insoluble in water. Amides have a strong tendency to reduce friction on various surfaces by forming a layer on surfaces. This coating action may be attributed to their hydrophobic character and strong hydrogen bonding. Primary, secondary, and bisamides are widely used as lubricating or slip agents and alkanolamides are commonly used as surfactants Amides in general are stable to elevated processing temperatures, air oxidation, and dilute acids and bases. The dehydration of amides which produces nitriles is of great commercial value. The most widely used synthetic route for primary amides is the reaction of fatty acid with anhydrous ammonia. Most monosubstituted and disubstituted amides can be synthesized with or without solvents from fatty acids and alkylamines. Most bisamides are prepared by the reaction of the primary fatty amide and formaldehyde in the presence of an acid catalyst, or by the reaction of ethylene diamine with fatty acid. Some primary fatty amides available from various manufacturers under different trade names are coco fatty amide, stearamide, hydrogenated‐tallow fatty amide, docosanamide, octadecenamide, and 13‐docosenamide.. Many substituted fatty acid amides are commercially available, but other, specialty substituted amides are of lower commercial volume.
Growth Regulators, Animal
Authors: Beermann Donald H.
Published: August 2004

The growth of animals can be defined as an increase in mass of whole body, tissue(s), organ(s), or cell(s) with time. Improved understanding of the control of metabolic aspects of growth has provided the opportunity to regulate animal growth. Improvement of rate and efficiency of growth benefits the producer. Improvement in composition of meat animals benefits the producer through more efficient gain and greater value, and benefits the processor through less labor requirement for trimming and removal of fat. The consumer benefits by receiving a quality, desirable food at a cost reflective of efficient production.

Four general classes of growth regulators are approved by the Food and Drug Administration (FDA) for use in food‐producing animals in the United States. These include naturally occurring and synthetic estrogens and androgens, ie, anabolic steroids; ionophores; antibiotics; and bovine somatotropin. Compounds in the first class, anabolic steroids, act as metabolism modifiers to alter nutrient partitioning toward greater rates of protein synthesis and deposition, thereby increasing the weight at which 25 to 30% lipid content in the body or carcass is achieved. Ionophores have highly selective antibiotic activity and appear to enhance feed conversion efficiency through effects on ruminal microbes. Antibiotics, administered at subtherapeutic doses, enhance growth through improving feed conversion efficiency and/or growth rate, with no consistent effect on body or carcass composition.

Two other classes of growth regulators, ie, somatotropin or somatotropin secretogogues, and select synthetic phenethanolamines, have been investigated for the ability to alter growth; no compound in either class has yet been approved by the FDA for use in animals raised for meat. In 1993, the FDA approved administration of recombinant bovine somatotropin for increasing milk production in dairy cows.

The U.S. Food and Drug Administration's Center for Veterinary Medicine thoroughly evaluates the proposed use of any compound, natural or synthetic, used in food‐producing animals for human food safety, safety to the animal of intended use, and safety to the environment.
Butylenes
Authors: Calamur Narasimhan , Carrera Martin E. , Wilsak Richard A.
Published: August 2004

Butylenes are C4H8mono‐olefin isomers: 1‐butene,cis‐2‐butene,trans‐2‐butene, and isobutylene (2‐methylpropene). These isomers are usually coproduced as a mixture and are commonly referred to as the C‐4 fraction. These C‐4 fractions are usually obtained as by‐products from petroleum refinery and petrochemical complexes that crack petroleum fractions and natural gas liquids. Since the C‐4 fractions almost always contain butanes, it is also known as the B–B stream. The linear isomers are referred to as butenes. The carbon–carbon double bond is the distinguishing feature of the butylenes and, as such, controls their chemistry. The carbon–carbon bond, acting as a substitute, affects the reactivity of the carbon atoms at the alpha positions through the formation of the allylic resonance structure. This structure can stabilize both positive and negative charges. Reactions of butylenes can be divided into two broad categories: those that take place at the double bond itself, destroying the double bond; and those that take place at alpha carbons. The C‐4 isomers are almost always produced commercially as by‐products in a petroleum refiner–petrochemical process. There are other commercial processes available for the production of butylenes. However, these are site‐ or manufacturer‐specific. Any of these processes can become an important source in the future. Several technologies are emerging for the production of isobutylene to meet the expected demand for isobutylene: deep catalytic cracking; superflex catalytic cracking; dehydrogenation of butanes; and the Coastal process of thermal dehydrogenation of butanes. There are four types of separation methods available: selective removal of isobutylene by polymerization and separation of 1‐butene; use of addition reactions with alcohol, acids, or water to selectively produce pure isobutylene and 1‐butene; selective extraction of isobutylene with a liquid solvent, usually an acid; and physical separation of isobutylene from 1‐butene by absorbents. There are three important processes for the production of isobutylene; the extraction process using an acid to separate isobutylene; the dehydration oftert‐butyl alcohol, formed in the Arco's Oxirane process; and the cracking of MTBE. Handling requirements are similar to liquefied petroleum gas (LPG). Butylenes are not toxic. The effect of long‐term exposure is not known; hence, they should be handled with care. They are volatile and asphyxiants. Care should be taken to avoid spills because they are extremely flammable.
Carbonyls
Authors: Wagner Frank S. , Kaesz Herbert D.
Published: August 2004

Carbon monoxide forms a host of metal carbonyl complexes, at least one for every transition metal. Mononuclear, polynuclear, and heteronuclear metal carbonyls are all known. The complexes, of general formula Mx(CO)y, may be charged or neutral; the metal or metals are in the zero oxidation state. Metal carbonyls are useful as reagents and catalysts in organic synthesis, and play a role in both the Reppe and the oxo processes, as well as in the preparation of synthetic fuels and in vapor deposition of purified metals.

The structure and bonding of the metal carbonyls, including that of cluster compounds, follow well‐defined rules. Synthesis of the metal carbonyls usually proceeds either from the reduction of the corresponding metal, initially in the form of a metallic salt, or via condensation of lower molecular weight compounds.
Cellulose
Authors: French Alfred D. , Bertoniere Noelie R. , Battista O. A. , Cuculo John A. , Gray Derek G.
Published: August 2004

This article covers nomenclature, sources, preparation, uses, microcrystalline cellulose, structural chemistry, reactions, solvents, and liquid crystals. Cellulose for commercial purposes comes mostly from wood and cotton, whereas cellulose for research comes from bacteria, algae, and ramie (also a textile fiber). Preparation includes pulping and purification, with a new alternative method of steam explosion. The pore structure of cellulose is mentioned, along with the build‐up of cellulose molecules into entire fibers. Emphasis is given to cellulose crystal structure, where recent research on the dominant natural form has made previous findings obsolete. Most cellulose is a mixture of two crystalline phases. Cellulose solutions are important to the rayon and cellophane industries, and new solvents are of interest because they may lessen pollution and might permit commercial production of stronger cellulosic materials through the formation of liquid crystals. Figures include the chemical and physical structures of the molecule, including in solution, the structure of a microfibril, and the unit cell structures of Cellulose I‐IV.
Cesium and Cesium Compounds
Authors: Burt Richard O.
Published: August 2004

Cesium is the most chemically active and rare of the naturally occurring Group 1 (IA) alkali metals. It is generally produced from pollucite by acid digestion to an intermediate cesium compound followed by thermochemical or electrolytic reduction. Production routes and properties of cesium and cesium compounds are described. Uses of cesium and cesium compounds continue to grow in electronics, in catalysts and organic synthesis, in analytical instrumentation, and in biotechnology. Cesium usage has also shown potential in such areas as magnetohydrodynamic power generation.
Chocolate and Cocoa
Authors: Zoumas B. L. , Smullen J. F.
Published: August 2004

Most chocolate and cocoa products consist of blends of roasted cocoa beans chosen for flavor and color characteristics. Cocoa may be blended in the bean, nib, or liquor state before going on to the chocolate making or pressing phase. Pressing separates the liquor into cocoa powder and cocoa butter, approximately 50:50.

The ingredients used for making chocolate are cocoa liquor, cocoa butter, sugar, and flavor for dark chocolate, plus milk for milk chocolate. These ingredients are mixed and then refined so the particle size of the ingredients is reduced to make the resultant chocolate smooth.

After refining, the chocolate is conched during which changes to viscosity, flavor, and texture occur. After conching, the product is standardized to fat content and viscosity, is tempered to obtain the correct form of fat crystal, and is deposited into molds to form the final shape. The chocolate is removed from the molds after cooling and then is wrapped and packaged ready for shipment to the customer.
Colloids
Authors: Bleier Alan
Published: August 2004

A colloid is a finely dispersed material, having a high surface‐area‐to‐volume ratio. It is usually a solid particle, but it may be a liquid droplet or a gas bubble. The differences in composition, structure, and interactions between the surface atoms or molecules and those on the interior impart colloids with diverse physicochemical properties that generally deviate from those of both the constituent atoms or molecules and the macroscopic material.

Many technological problems relate to the behavior of colloids, especially those dispersed in a liquid or gaseous fluid. Commercial examples include metals, magnetic powders, catalysts, ceramics, minerals, oil recovery, technical glasses, paints and pigments, polymers, pulp and paper, prepared foods, pharmaceuticals, fibers, detergents, and purified water. Natural and biological systems can also depend on the behavior of colloids, and soil science and plant nutrition, meteorology, hematology, membrane science, and medical technology furnish numerous examples. Thus the ubiquity and importance of colloids have made the ability to control their formation, destruction, or stabilization a critical problem, irrespective of whether the colloidal material is deemed desirable or undesirable.

This article addresses the physical and chemical properties of colloidal materials, their widespread applications, and the hazards associated with finely dispersed particulates.
Colorants for Ceramics
Authors: Eppler Rchard A.
Published: August 2004

Ceramics may be colored by melting a transition metal into a glass or dispersing it in a ceramic body, by precipitating a colored crystal in a transparent matrix, or by dispersing in a matrix an insoluble crystal or crystals that are colored. The latter is the principal method of coloration of ceramic coatings. Most of the crystals used for ceramic pigments are complex oxides. The choices to obtain the principal colors are described in this article. Also discussed are the factors to be considered in selecting a ceramic pigment: processing stability requirements, pigment uniformity and reproducibility, particle size distribution, dispersibility, and compatibility of all materials to be used.
Dimethylacetamide
Authors: Watts J. C. , Larson P. A.
Published: August 2004

Dimethylacetamide, DMAC, mol wt 87.12, CH
3
CON (CH
3
)
2
, is a colorless, high boiling polar solvent. DMAC is a good solvent for a wide range of organic and inorganic compounds. The polar nature of DMAC enables it to act as a combined solvent and reaction catalyst, often producing high yields in short time periods. The chemical reactions of DMAC are typical of those of disubstituted amides. Dimethylacetamide can be produced by the reaction of acetic acid and dimethylamine, or by the reaction of acetic anhydride and dimethylamine. DMAC is capable of producing systemic injury, principally cumulative damage to the liver and kidney, when repeatedly inhaled or absorbed through the skin. The uses of dimethylacetamide are very similar to those for dimethylformamide.
Dyes, Anthraquinone
Authors: Hattori Makoto
Published: August 2004

The history and current situation of the anthraquinone dye industry, and basic chemistry of anthraquinone compounds (color and structure, and general method of synthesis) are discussed. The manufacturing processes of key intermediates are illustrated both on the basis of industrial importance and the latest advances in research and development. Emphasis is placed on process improvements in view of environmental issues.

The properties and the preparation of anthraquinone dyes are discussed according to dye type: reactive dyes (bromamine acid derivatives with sulfatoethylsulfonyl, chlorotriazine, and other heterocyclic functional group), disperse dyes (1‐amino‐4‐hydroxy‐anthraquinones, 1,4‐diaminoanthraquinone‐2,3‐dicarboxyimides, 1,4,5,8‐substituted anthraquinones, 1,4‐diaminoanthraquinones, andN‐substituted‐1‐amino‐4‐hydroxyanthraquinones), acid dyes (bromamine acid derivatives and quinizarin derivatives), vat dyes (benzanthrones, indanthrones, anthrimides, anthrimidocarbazoles, acylaminoanthraquinones, anthraquinoneazoles, anthraquinone acridones, anthrapyrimidines, and other highly condensed ring systems), and mordant dyes. Recent advances in functional dyes related to the electronics industry are also presented. Economic aspects of the anthraquinone dye industry are included and health and safety information is presented.
Chromogenic Materials, Electrochromic
Authors: Greenberg Charles B.
Published: August 2004

Electrochromism is a reversible color change in a material, often a thin film, that accompanies an oxidation‐reduction reaction driven by a small current at low voltage. It occurs at or near room temperature in both cathodically colored and anodically colored inorganic and organic compounds. It is accompanied by ion insertion/extraction (doping/undoping) for charge balance in thin solid films. Electrochromic chromogenic materials are divided into two groups based on whether or not insertion/extraction occurs or is distinguishing. For the smaller, noninsertion group, reversible coloration occurs in solution or is associated with reversible electrodeposition from solution. The best known members are viologens.

There are three subsets of the insertion/extraction group: (1) cathodically colored inorganic materials usually color with either H+or alkali‐ion insertion. The best known film is amorphous tungsten oxide, in part because of its relatively high coloration efficiency in the visible region; (2) anodically colored inorganic materials include Prussian blue, also having a high coloration efficiency, and hydrated oxides of iridium and nickel. Often, K+is inserted for Prussian blue. There is a lively debate about whether H+or OH−is active for the hydrated oxides; (3) doped/undoped organic films color both anodically and cathodically, in general. There is must less known about this form of electrochromism in literature which, as a whole, has been reviewed through 1990.
Esters, Organic
Authors: Tau Kwoliang D. , Elango Varadaraj , McDonough Joseph A.
Published: August 2004

This article presents important information related to carboxylic esters including nomenclature, physical properties, chemical reactions, occurrence and preparation, analysis, health and safety issues, handling regulations, and commercial uses. It also includes figures for United States production and sales of carboxylic esters in 1990.

Chemical reactions of esters discussed are hydrolysis (acidic, basic, steam, and enzymatic), transesterification, ammonolysis and aminolysis, reduction (catalytic and stoichiometric), enolate reactions, Grignard and related reactions, acyloin condensation, pyrolysis, substitution, alkylation, and rearrangement.

Analytical methods for characterization as well as spectral behavior of esters are given. Discussion on health, safety, and handling focuses on ester's reactivity, flash point, autoignition temperature, toxicity data, and permissible exposure limits.

Uses of esters in areas such as solvents, plasticizers, resins, plastics, coatings, lubricants, perfumes, flavors, cosmetics, soap, surface‐active agents, medicinals, herbicides, and pesticides are described. Some specific examples are also given.
Ethers
Authors: Karas Lawrence , Piel W. J.
Published: August 2004

An overview of ethers is provided that covers the general types of ethers, their synthesis reactions, properties, and some general uses in industry. More detail and expanded discussion is provided on ethyl ether, tetrahydrofuran (THF), and methyl tertiary butyl ether (MTBE), which represent three of the ethers with the highest commercial volumes. One of the fastest growing and largest uses of ethers is for gasoline blending. Though initially developed to provide octane in gasoline, fuel‐grade ethers are now used to add oxygen to the gasoline mixture, which helps improve combustion and reduce tailpipe emissions from automobiles. Besides MTBE, other possible fuel ethers such as ethyl tertiary butyl ether (ETBE) and tertiary amyl ether (TAME) are also noted.
Fluorine
Authors: Shia George
Published: August 2004

Fluorine, the first member of the halogen family, is the most reactive nonmetal, and capable of reacting with all of the other elements, except the gases helium, neon, and argon, oxidizing most elements to their highest oxidation. Although fluorine is highly corrosive, commercial uses have been developed. The largest industrial usage for fluorine is in the production of uranium hexafluoride, which is used in the uranium enrichment process, and in the production of sulfur hexafluoride, a gaseous dielectric. Fluorine is also used to make perfluorinated materials and for surface treatment of polyolefin‐based containers.

Fluorine is produced by electrolysis of molten potassium bifluoride in specially designed cells having steel or Monel cathodes and carbon anodes. The selection of the anode carbon is critical. This manufacturing process and the special equipment needed for handling fluorine are described. Most fluorine produced is used captively for synthesis.
Coal Conversion Processes, Gasification
Authors: Mahagaokar Uday , Krewinghaus A. B.
Published: August 2004

Coal gasification is a well‐proven technology that provides an excellent way to utilize vast resources of coal efficiently and cleanly. The near‐term application of coal gasification is in conjunction with combined cycle systems to generate electricity. Modern coal gasification processes produce high pressure syngas, which can be fed as fuel to a gas turbine. The high efficiency derived from combining gas turbine cycles with steam turbine cycles, along with significant environmental benefits, makes coal gasification combined cycle (CGCC) power plants more attractive than conventional technologies that generate power by coal combustion.

Gasification technologies are described for various types of feedstocks. The chemistry of coal gasification is presented and process results are shown for several coals with a focus on gasifier performance and process efficiency. Other potential applications of coal involve the use of syngas chemistry to produce chemicals.
Gelatin
Authors: Keenan Thomas R.
Published: August 2004

Gelatin is a protein obtained by partial hydrolysis of collagen, the chief protein component in skin, bones, hides, and white connective tissues of the animal body. Type A gelatin is produced by acid processing of collagenous raw material; type B is produced by alkaline or lime processing. Because it is obtained from collagen by a controlled partial hydrolysis and does not exist in nature, gelatin is classified as a derived protein.

Uses of gelatin are based on its combination of properties; reversible gel‐to‐sol transition of aqueous solution; viscosity of warm aqueous solutions; ability to act as a protective colloid; water permeability; and insolubility in cold water, but complete solubility in hot water. It is also nutritious. These properties are utilized in the food, pharmaceutical, and photographic industries. In addition, gelatin forms strong, uniform, clear, moderately flexible coatings which readily swell and absorb water and are ideal for the manufacture of photographic films and pharmaceutical capsules.
Acetic Acid, Halogenated Derivatives
Authors: Morris Earl D. , Bost John C.
Published: August 2004

The most important of the halogenated derivatives of acetic acid is chloroacetic acid, which has wide applications as an industrial chemical intermediate in the manufacture of cellulose ethers, herbicides, and thioglycolic acid. Most chloroacetic acid is produced by the chlorination of acetic acid. Chloroacetic acid is extremely corrosive and will cause serious chemical burns, and is readily absorbed through the skin; contamination of 5–10% of the skin is usually fatal. Sodium chloroacetate, C2H2ClO2Na, is produced by reaction of chloroacetic acid with sodium hydroxide or sodium carbonate. Dichloroacetic acid, C2H2Cl2O2, is a reactive intermediate in organic synthesis. It has been manufactured by the chlorination of acetic and chloroacetic acids and by other means. Trichloroacetic acid, C2HCl3O2, forms white deliquescent crystals. Sodium trichloroacetate, C2Cl3O2Na, is used as a herbicide. Chloroacetyl chloride (ClCH2COCl) is the corresponding acid chloride of chloroacetic acid, and is manufactured by reaction of chloroacetic acid with chlorinating agents. Much of the chloroacetyl chloride produced is used captively as a reactive intermediate. It is useful in many acylation reactions and in the production of adrenalin, diazepam, and chloroacetic anhydride. Two chloroacetate esters of industrial importance are methyl chloroacetate, C3H5ClO2, and ethyl chloroacetate, C4H7ClO2. Both are used as agricultural and pharmaceutical intermediates. Other derivatives are bromoacetic acid, dibromoacetic acid, tribromoacetic acid, iodoacetic acid, diiodoacetic acid, and triiodoacetic acid.
Hazard Analysis and Risk Assessment
Authors: Crowl Daniel A.
Published: August 2004

The purpose of hazard analysis and risk assessment in the chemical process industry is to
(1)
characterize the hazards associated with a chemical facility;
(2)
determine how these hazards can result in an accident; and
(3)
determine the risk, ie, the probability and the consequence of these hazards. Methods for performing hazard analysis and risk assessment include safety review, checklists, Dow Fire and Explosion Index, what‐if analysis, hazard and operability analysis (HAZOP), failure modes and effects analysis (FMEA), fault tree analysis, and event tree analysis.

In order to complete an assessment of risk, a probability must be determined.

A more recent concept which could have significant impact on future designs is that of inherent safety. Hazard avoidance is performed by three techniques. First, there is substitution. This means substituting a less hazardous material for the material in use. The second method for inherent safety is attenuation, ie, operating the process at lower temperatures and pressures. The last inherent safety technique is intensification. This means using much smaller inventories of hazardous raw and intermediate materials, and reducing process hold‐up and inventories.
Insect Control Technology
Authors: Metcalf Robert L.
Published: August 2004

Insects are the most numerous of living organisms and the nearly one million described species constitute approximately 72% of all animal species. Of these about 1% are considered significant pests. This article summarizes the chemistry, properties, uses, and advantages and disadvantages of most of the chemicals used for insect control. These include many products of largely historical interest as well as some not registered for use in the United States but used elsewhere in the world.

Approximately 70% of all insecticide use is in agriculture and applications are generally made directly to raw agricultural commodities to protect plants and animals from insect attacks. With the exception of microbial insecticides, nearly all of the uses of insecticides result in residues of the various chemicals and their degradation products.

Basic guidelines for the limitations of pesticide residues in raw agricultural commodities are established by national and international agencies. International standardization is highly desirable for trade in foodstuffs and values for more than 100 pesticides used on more than 1600 specified food crops are reviewed periodically. Vol. 14, pp. 524–602, 77 refs. to 1993.
Furnaces, Electric, Introduction
Authors: Sommer Richard A.
Published: August 2004

Furnaces, Electric, Introduction. Richard A. Sommer (Consultant). The term electric furnace applies to all furnaces that use electrical energy as their sole source of heat. Electric furnaces are used for heating solid materials to desired temperatures below their melting points for subsequent processing, or melting materials for subsequent casting into desired shapes. Classification is by the manner in which the electrical energy is converted into heat. Three types of furnaces are widely used in industry: electric resistance furnaces, arc furnaces, and electric induction furnaces.
Maleic Anhydride, Maleic Acid, and Fumaric Acid
Authors: Felthouse Timothy R. , Burnett Joseph C. , Mitchell Scott F. , Mummey Michael J.
Published: August 2004

Scientific and technological developments in the manufacture and use of maleic anhydride, maleic acid, and fumaric acid are reviewed since 1980. Physical and chemical properties for these three chemicals are updated with literature citations when available. Key derivatives are summarized including acid chlorides and reaction products of these chemicals formed from acylation, alkylation, amidation, coordination to metal atoms, cycloaddition, decomposition, electrophilic addition, esterification, free‐radical reactions, Grignard‐type reactions, halogenation, hydration, hydroformylation, isomerization, nucleophilic addition, oxidation, polymerization, reduction, and sulfonation. Manufacturing processes for maleic anhydride are described including those using fixed‐bed, fluidized‐bed, and transport‐bed technologies for selective oxidation of butane. A survey is given of catalyst developments since about 1980. Regardless of the reactor type used, all catalysts producing maleic anhydride from butane consist of a vanadyl pyrophosphate phase, (VO)2P2O7. Details are presented on maleic anhydride and its two diacid isomers with respect to distribution, economic aspects, specifications, analytical and test methods, toxicology, and principal uses.
Ceramics, Mechanical Properties and Behavior
Authors: Glass Jill
Published: August 2004

Structural ceramics are used in applications such as gas turbines, machining, heat exchangers, aerospace components, armor, thermal barrier coatings, and bearings. Advantages of ceramics over metals include dimensional stability; low densities, which translate into weight savings and increased fuel efficiencies; high temperature capabilities; and corrosion resistance.

The overriding concern with regard to the mechanical performance of ceramics is their brittleness and hence sensitivity to flaws. There is usually little or no warning that failure is imminent because deformation strain prior to failure is usually less than 0.1%. As a result, a primary aim of structural ceramics research has been the development of tougher ceramics. The mechanical properties of ceramics are very sensitive to starting materials, forming processes, heat treatment conditions, and surface preparation.

Fracture analysis plays an important role in understanding the relationships between structure and mechanical properties, and the conditions that lead to failure
Methacrylic Polymers
Authors: Novak Ronald W. , Lesko Patricia M.
Published: August 2004

Methacrylic polymers and copolymers are noted for their water‐clear color and excellent durability. They are available with a wide range of physical properties which makes them suitable for a broad variety of applications. Physical properties of the important commercial monomers and the polymers they produce are given. The basic principles utilized in the manufacture of methacrylic polymers by free‐radical processes are discussed. These processes include bulk, solution, emulsion, and suspension polymerizations. Graft and anionic polymerizations are also reviewed. Economic, health, and safety perspectives are given. Leading references describing the uses of methacrylic polymers in a variety of applications are noted.
Molybdenum Compounds
Authors: Stiefel Edward I.
Published: August 2004

Molybdenum, found naturally as molybdenite, is converted through MoO3to compounds in a wide range of oxidation states, coordination numbers, and states of aggregation. The diverse chemistry of molybdenum is manifest in a wide array of uses in biological and industrial systems. Molybdenum, an essential component of many enzymes, plays a primary role in nitrogen fixation and nitrate reduction in bacteria and plants, and sulfite and xanthine oxidation for microorganisms, plants, and animals. Industrially, molybdenum compounds are important in lubrication, where the disulfide and oil‐soluble molybdenum sulfur complexes serve as antifriction and antiwear agents; in hydrodesulfurization and hydrotreating of petroleum; ammoxidation and other catalytic processes; in anticorrosion formulations; as flame and smoke retardants; and in a variety of coatings and pigments. Biomedically, molybdenum is used in nuclear medicine and is under study in a number or therapeutic procedures. The trioxide, several molybdates, and the disulfide are available as bulk chemicals.
Naphthalene
Authors: Mason Robert T.
Published: August 2004

This article deals mainly with naphthalene. The hydrogenated naphthalenes, the alkylnaphthalenes (particularly methyl‐ and isopropylnaphthalenes), and acenaphthalene also are discussed. These aromatic hydrocarbons have the expected properties and undergo the usual reactions of electrophilic aromatic substitution as well as oxidation, a significant commercial reaction.

Coal tar and petroleum are the sources of naphthalene in the United States. The principal use of naphthalene is for phthalic anhydride manufacture. Naphthalene is also a raw material for synthesis of pesticides, dispersants, and wetting agents.
Polycarbonates
Authors: Brunelle Daniel J.
Published: August 2004

Polycarbonates are an unusual and extremely useful class of polymers. The vast majority of polycarbonates are based on bisphenol A (BPA) and sold under the trade names Lexan, Makrolon, Calibre, and Panlite. BPA polycarbonates having high glass‐transition temperatures are widely regarded for optical clarity and exceptional impact resistance and ductility at room temperature and below. Other properties such as modulus, dielectric strength, or tensile strength are comparable to other amorphous thermoplastics at similar temperatures below their respective glass‐transition temperatures. Polycarbonates are prepared commercially by two processes: Schotten‐Baumann reaction of phosgene and an aromatic diol in an amine‐catalyzed interfacial condensation reaction, or via base‐catalyzed transesterification of a bisphenol with a monomeric carbonate such as diphenyl carbonate. Important products are also based on polycarbonates in blends with other polymers, copolymers, branched resins, flame‐retardant compositions, foams, and other materials. Polycarbonate, produced globally, has been the object of research studies, owing to its widespread utility and unusual properties. This article summarizes the preparation, properties, and utility of polycarbonates.