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Reuse of oilfield‐produced water (OPW) for crop irrigation has the potential to make a critical difference in the water budgets of highly productive but drought‐stressed agricultural watersheds. This is the first peer‐reviewed study to evaluate how trace metals in OPW used to irrigate California crops may affect human health. We modeled and quantified risks associated with consuming foods irrigated with OPW using available concentration data. The probabilistic risk assessment simulated OPW metal concentrations, crop uptake, human exposures, and potential noncancer and carcinogenic health effects. Overall, our findings indicate that there is a low risk of ingesting toxic amounts of metals from the consumption of tree nuts, citrus, grapes, and root vegetables irrigated with low‐saline OPW. Results show increased arsenic cancer risk (at 10−6) for adult vegetarians, assuming higher consumption of multiple foods irrigated with OPW that contain high arsenic concentrations. All other cancer risks are below levels of concern and all noncancer hazards are far below levels of concern. Arsenic risk concerns could be mitigated by practices such as blending high‐arsenic OPW. Future risk assessment research should model the risks of organic compounds in OPW, as our study focused on inorganic compounds. Nevertheless, our findings indicate that low‐saline OPW may provide a safe and sustainable alternative irrigation water source if water quality is adequately monitored and blended as needed prior to irrigation.

While oilfield produced water (PW) is one of the largest, unclaimed wastewater streams of the oil industry, it could potentially be used as a cultivation medium for microalgae. Microalgae could help with the remediation of this water while also delivering biomass that can be transformed into valuable byproducts such as biofuels. The coupling of these two purposes is expected to cut production costs of biofuels while aiding environmental protection. In this study, we compared the cultivation capacity of the marine model diatom Phaeodactylum tricornutum in media at varying salinities and in media composed of PW from two oilfields in the Central Valley of California that differed drastically in the concentration of inorganic and organic constituents. Specifically, we measured the carrying capacity of these media, the maximum growth rates of P. tricornutum, its cellular lipid accumulation capacity, and its capacity to remediate the most polluted PW source. Our study shows that P. tricornutum can successfully adjust to the tested cultivation media through processes of short-term acclimation and long-term adaptation. Furthermore, the cultivation of P. tricornutum in the most heavily polluted PW source led to significant increases in cell yield and improved photosynthetic capacity during the stationary phase, which could be attributed chiefly to the higher levels of nitrate present in this PW source. Chemical water analyses also demonstrated the capability of P. tricornutum to remediate major nutrient content and potentially harmful elements like fluorine and copper. Because P. tricornutum is amenable to advanced genetic engineering, which could be taken advantage of to improve its cultivation resilience and productivity in an economic setting, we propose this study as a step towards essential follow-up studies that will identify the genetic regulation behind its growth in oilfield PW media and its remediation of the PW constituents.

The consecutive occurrence of drought and reduction in natural water availability over the past several decades requires searching for alternative water sources for the agriculture sector in California. One alternative source to supplement natural waters is oilfield produced water (OPW) generated from oilfields adjacent to agricultural areas. For over 25 years, OPW has been blended with surface water and used for irrigation in the Cawelo Water District of Kern County, as permitted by California Water Board policy. This study aims to evaluate the potential environmental impact, soil quality, and crop health risks of this policy. We examined a large spectrum of salts, metals, radionuclides (226Ra and 228Ra), and dissolved organic carbon (DOC) in OPW, blended OPW used for irrigation, groundwater, and soils irrigated by the three different water sources. We found that all studied water quality parameters in the blended OPW were below current California irrigation quality guidelines. Yet, soils irrigated by blended OPW showed higher salts and boron relative to soils irrigated by groundwater, implying long-term salts and boron accumulation. We did not, however, find systematic differences in 226Ra and 228Ra activities and DOC in soils irrigated by blended or unblended OPW relative to groundwater-irrigated soils. Based on a comparison of measured parameters, we conclude that the blended low-saline OPW used in the Cawelo Water District of California is of comparable quality to the local groundwater in the region. Nonetheless, the salt and boron soil accumulation can pose long-term risks to soil sodification, groundwater salinization, and plant health; as such, the use of low-saline OPW for irrigation use in California will require continual blending with fresh water and planting of boron-tolerant crops to avoid boron toxicity.

Introduction: children with cerebral palsy (CP) have multiple risk factors for low bone mineral density or osteoporosis. Objective: to explore the association between bone mineral density (BMD) and biochemical and hormonal indicators of bone metabolism in children with quadriplegic cerebral palsy (CP). Methods: a cross-sectional analytical study included 59 participants from six to 18 years of age with quadriplegic CP. Serum concentrations of calcium, phosphorus, 25OHD metabolite, parathyroid hormone (PTH), alkaline phosphatase, and thyroid hormones were determined using standardized methods. The BMD measurement was obtained from the lumbar spine expressed in g/cm2 and Z-score. Unpaired Student's t-test, Chi-square test, odds ratio and Pearson's correlation were performed. Results: participants with CP and malnutrition had lower serum concentrations of calcium, phosphorus and alkaline phosphatase. Those who had low BMD showed lower serum concentrations of calcium, phosphorus and alkaline phosphatase. Most participants with low and normal BMD had vitamin D deficiency (27.1% and 10%) and insufficiency (35.4% and 30%), respectively. There was a significant correlation between BMD and serum concentrations of calcium, phosphorus, alkaline phosphatase, vitamin D and thyroid-stimulating hormone (TSH). There were no differences in the biochemical and hormonal indicators by level of gross motor function, use of anticonvulsants and oral versus enteral feeding method. Conclusion: malnutrition and alteration of vitamin D nutritional status were associated with low BMD and alterations of biochemical indicators of bone metabolism in pediatric patients with quadriplegic CP. The relationship between BMD and biochemical indicators of bone metabolism in children with quadriplegic CP was also demonstrated.Introducción: los niños con parálisis cerebral (PC) presentan múltiples factores de riesgo de densidad mineral ósea baja u osteoporosis. Objetivo: explorar la asociación entre la baja densidad mineral ósea (DMO) e indicadores bioquímicos y hormonales del metabolismo óseo en niños con PC cuadripléjica. Métodos: un estudio transversal analítico incluyó a 59 participantes de entre seis y 18 años de edad con PC cuadripléjica. Las concentraciones séricas de calcio, fósforo, metabolito 25OHD, hormona paratiroidea (PTH), fosfatasa alcalina y hormonas tiroideas se determinaron utilizando métodos estandarizados. La medición de DMO se obtuvo de la columna lumbar expresada en g/cm2 y puntaje Z. Se realizaron pruebas t de Student no pareada, Chi-cuadrado, razón de momios y correlación de Pearson. Resultados: los participantes con PC y desnutrición tenían concentraciones séricas más bajas de calcio, fósforo y fosfatasa alcalina. Los participantes con DMO baja tuvieron menor concentración sérica de calcio, fósforo y fosfatasa alcalina. Los participantes con DMO baja y normal tenían deficiencia de vitamina D (27.1% y 10%) e insuficiencia (35.4% y 30%), respectivamente. Hubo una correlación significativa entre DMO y las concentraciones séricas de calcio, fósforo, fosfatasa alcalina, vitamina D y hormona estimulante de la tiroides. Conclusión: la desnutrición y la alteración del estado nutricio de la vitamina D se asociaron con DMO baja y alteraciones de los indicadores bioquímicos del metabolismo óseo. Se demostró una asociación entre DMO e indicadores bioquímicos y hormonales del metabolismo óseo en niños con PC cuadripléjica.

Oils and fats derived from animals and plants provide a good renewable source for polymer precursors. In this investigation, fatty acids derived from plant oils and diols were used as monomers to produce polyesters by melt polycondensation. Sebacic acid, hexanediol, and hydroquinone were used as precursors in the polymer synthesis. The polymers were characterized by gel permeation chromatography, Fourier transform infrared spectroscopy, three-bending point flexural test, X-ray diffraction, tensile testing, and contact angle. The resulting polyesters were blended with epoxies to create materials with an increased elongation at break without affecting other mechanical properties.

espanolIntroduccion: los ninos con paralisis cerebral (PC) presentan multiples factores de riesgo de densidad mineral osea baja u osteoporosis. Objetivo: explorar la asociacion entre la baja densidad mineral osea (DMO) e indicadores bioquimicos y hormonales del metabolismo oseo en ninos con PC cuadriplejica. Metodos: un estudio transversal analitico incluyo a 59 participantes de entre seis y 18 anos de edad con PC cuadriplejica. Las concentraciones sericas de calcio, fosforo, metabolito 25OHD, hormona paratiroidea (PTH), fosfatasa alcalina y hormonas tiroideas se determinaron utilizando metodos estandarizados. La medicion de DMO se obtuvo de la columna lumbar expresada en g/cm2 y puntaje Z. Se realizaron pruebas t de Student no pareada, Chi-cuadrado, razon de momios y correlacion de Pearson. Resultados: los participantes con PC y desnutricion tenian concentraciones sericas mas bajas de calcio, fosforo y fosfatasa alcalina. Los participantes con DMO baja tuvieron menor concentracion serica de calcio, fosforo y fosfatasa alcalina. Los participantes con DMO baja y normal tenian deficiencia de vitamina D (27.1% y 10%) e insuficiencia (35.4% y 30%), respectivamente. Hubo una correlacion significativa entre DMO y las concentraciones sericas de calcio, fosforo, fosfatasa alcalina, vitamina D y hormona estimulante de la tiroides. Conclusion: la desnutricion y la alteracion del estado nutricio de la vitamina D se asociaron con DMO baja y alteraciones de los indicadores bioquimicos del metabolismo oseo. Se demostro una asociacion entre DMO e indicadores bioquimicos y hormonales del metabolismo oseo en ninos con PC cuadriplejica. EnglishIntroduction: children with cerebral palsy (CP) have multiple risk factors for low bone mineral density or osteoporosis. Objective: to explore the association between bone mineral density (BMD) and biochemical and hormonal indicators of bone metabolism in children with quadriplegic cerebral palsy (CP). Methods: a cross-sectional analytical study included 59 participants from six to 18 years of age with quadriplegic CP. Serum concentrations of calcium, phosphorus, 25OHD metabolite, parathyroid hormone (PTH), alkaline phosphatase, and thyroid hormones were determined using standardized methods. The BMD measurement was obtained from the lumbar spine expressed in g/cm2 and Z-score. Unpaired Student’s t-test, Chi-square test, odds ratio and Pearson’s correlation were performed. Results: participants with CP and malnutrition had lower serum concentrations of calcium, phosphorus and alkaline phosphatase. Those who had low BMD showed lower serum concentrations of calcium, phosphorus and alkaline phosphatase. Most participants with low and normal BMD had vitamin D deficiency (27.1% and 10%) and insufficiency (35.4% and 30%), respectively. There was a significant correlation between BMD and serum concentrations of calcium, phosphorus, alkaline phosphatase, vitamin D and thyroid-stimulating hormone (TSH). There were no differences in the biochemical and hormonal indicators by level of gross motor function, use of anticonvulsants and oral versus enteral feeding method. Conclusion: malnutrition and alteration of vitamin D nutritional status were associated with low BMD and alterations of biochemical indicators of bone metabolism in pediatric patients with quadriplegic CP. The relationship between BMD and biochemical indicators of bone metabolism in children with quadriplegic CP was also demonstrated.

This study demonstrated the relationship of low bone mineral density (BMD) with the degree of motor impairment, method of feeding, anthropometric indicators, and malnutrition in children with quadriplegic cerebral palsy (CP). The control of these factors could optimize adequate bone mineralization, avoid the risk of osteoporosis, and would improve the quality of life. The purpose of the study is to explore the relationship between low BMD and nutritional status in children with quadriplegic CP. A cross-sectional analytical study included 59 participants aged 6 to 18 years with quadriplegic CP. Weight and height were obtained with alternative measurements, and weight/age, height/age, and BMI/age indexes were estimated. The BMD measurement obtained from the lumbar spine was expressed in grams per square centimeter and Z score (Z). Unpaired Student’s t tests, chi-square tests, odds ratios, Pearson’s correlations, and linear regressions were performed. The mean of BMD Z score was lower in adolescents than in school-aged children (p = 0.002). Patients with low BMD were at the most affected levels of the Gross Motor Function Classification System (GMFCS). Participants at level V of the GMFCS were more likely to have low BMD than levels III and IV [odds ratio (OR) = 5.8 (confidence interval [CI] 95% 1.4, 24.8), p = 0.010]. There was a higher probability of low BMD in tube-feeding patients [OR = 8.6 (CI 95% 1.0, 73.4), p = 0.023]. The probability of low BMD was higher in malnourished children with weight/age and BMI indices [OR = 11.4 (1.3, 94), p = 0.009] and [OR = 9.4 (CI 95% 1.1, 79.7), p = 0.017], respectively. There was a significant relationship between low BMD, degree of motor impairment, method of feeding, and malnutrition. Optimizing these factors could reduce the risk of osteopenia and osteoporosis and attain a significant improvement of quality of life in children with quadriplegic CP.

Fourier transform infrared (FTIR) spectra of cotton fibers harvested at different stages of development were acquired using Universal Attenuated Total Reflectance FTIR (UATR-FTIR). The main goal of the study was to monitor cell wall changes occurring during different phases of cotton fiber development. Two cultivars of Gossypium hirsutum L. were planted in a greenhouse (Texas Marker-1 and TX55). On the day of flowering, individual flowers were tagged and bolls were harvested. From fibers harvested on numerous days between 10 and 56 dpa, the FTIR spectra were acquired using UATR (ZnSe-Diamond crystal) with no special sample preparation. The changes in the FTIR spectra were used to document the timing of the transition between primary and secondary cell wall synthesis. Changes in cellulose during cotton fiber growth and development were identified through changes in numerous vibrations within the spectra. The intensity of the vibration bands at 667 and 897 cm(-1) correlated with percentage of cellulose analyzed chemically.

Cotton fabric surface was successfully functionalized with microwave plasma (2.45 GHz, 500 W) to impart water repellency. The hydrophobic agent used was oleic acid (CH 3 (CH 2 ) 7 CH CH(CH 2 ) 7 COOH), a fatty acid derived from various plant seed oils. Non-polymerizing gas (Argon) was used to create the plasma. The exposure of the cellulose to Ar-plasma generated radicals, which were subsequently used to initiate co-polymerization reactions with oleic acid. The FTIR spectra showed the presence of additional vibrations located at 2918, 2849, and 1707 cm −1 in the functionalized samples. Dynamic contact angle measurements were performed to assess the hydrophobic properties of the functionalized cotton fabric. The grafted cotton fabric showed excellent water repellency. In addition, the use of plant-derived monomers and biopolymers provides a different approach to use renewable resources to create functionalized biopolymeric substrates.

Thermal decomposition of cellulose has been widely studied for the past several years. It has been reported that the source of cellulose and its composition greatly affect its pyrolysis. One of the most widely used analytical tools for the study of cellulose pyrolysis is thermogravimetric (TG) analysis. Several model-fitting methods have been employed to study cellulose pyrolysis kinetics. An alternative to the model-fitting approach is the so-called model-free method developed by Vyazovkin. This isoconversional technique calculates the activation energy as a function of the degree of the conversion. In this article, the pyrolysis of cellulose in cotton fibers compared to microcrystalline cellulose (Avicel, PH 105) was investigated. TG curves were acquired as a function of the heating rates (4, 5, 8, 10, and 16 °C min−1) and the model-free method was used to analyze the data. Activation energies of cotton fibers and Avicel were obtained, and compared to the data reported in the literature. In addition, models for isothermal decomposition were calculated and compared with experimental data at the same temperature.

In this research, thermogravimetric analysis (TGA) was used to investigate the structural changes that occur during cotton fiber development starting at 10 days post-anthesis (dpa). The percent weight losses attributed to water, non-cellulosic materials, and cellulose macromolecules were calculated from the thermograms. Valuable information was obtained related to the composition of the cell wall and the timing of the transition between the primary cell wall and the secondary cell wall. The results indicated that the two cultivars investigated (TX19 and TX55) exhibited different structural evolution. The transition phase between the primary cell wall and the secondary cell wall occurs between 17 and 18 dpa in fibers from the TX19 cultivar, while this transition occurs between 21 and 24 dpa for fibers from the TX55 cultivar. These conclusions are in agreement with the results obtained with Fourier transform infrared spectroscopy.

Two cotton cultivars TX19 and TX55 (Gossypium hirsutum L. cv.) were planted in the greenhouse and fibers were harvested at different stages of development. The percentage of sugars present on the fibers was determined by High Performance Liquid Chromatography and the cellulose content was determined using the anthrone method. The percentage of sugars (sucrose, glucose, fructose, and galacturonic acid) showed statistically significant changes during fiber development. The decrease in the percentages of these sugars as the secondary cell wall develops was associated with an increase in the cellulose content. It is important to point out that these analyses were done on intact fibers, no cell wall extractions and purifications were performed.

Cotton fiber maturity is a major yield component and an important fiber quality trait that is directly linked to the quantity of cellulose deposited during the secondary cell wall (SCW) biogenesis. Cotton fiber development consists of five major overlapping stages: differentiation, initiation, polar elongation, secondary cell wall development, and maturation. The transition period between 16 and 21 dpa (days post anthesis) is regarded to represent a major developmental stage between the primary cell wall and the SCW. Fourier Transform Infrared spectroscopy was used to investigate the structural changes that occur during the different developmental stages. The IR spectra of fibers harvested at different stages of development (10, 14, 17, 18, 19, 20, 21, 24, 27, 30, 36, 46, and 56 dpa) show the presence of vibrations located at 1,733 cm−1 (C=O stretching originating from esters or amides) and 1,534 cm−1 (NH2 deformation corresponding to proteins or amino acids). The results converge towards the conclusion that the transition phase between the primary cell wall and the secondary cell wall occurs between 17 and 18 dpa in fibers from TX19 cultivar, while this transition occurs between 21 and 24 dpa in fibers from TX55 cultivar.

Graphene sheets were produced through chemical exfoliation of natural graphite flake and hydrazine conversion. Subsequently, graphene sheets were assembled into a thin film, and microscale liquid droplets were placed onto the film surface for measurement of wettability and contact angle. It is found that a graphene oxide sheet is hydrophilic and a graphene sheet is hydrophobic. Isolated graphene layers seem more difficult to wet in comparison to graphite, and low adhesion work was found in the graphene-liquid interface. Approximation of solid-liquid interfacial energy with the equation of state theory was applied to determine the graphene surface energy. The results indicate that surface energy of graphene and graphene oxide is 46.7 and 62.1 mJ/m2, respectively, while natural graphite flake shows a surface free energy of 54.8 mJ/m2 at room temperature. These results will provide valuable guidance for the design and manufacturing of graphene-based biomaterials, medical instruments, structural composites, electronics, and renewable energy devices.

Universal attenuated total reflectance Fourier transform infrared (UATR-FTIR) spectroscopy and thermogravimetric analysis (TGA) were used to investigate the structural changes of cotton (Gossypium hirsutum L.) fibers as a function of developmental programming. The presence of noncellulosic compounds (wax, protein, hemicelluloses, pectic substances, amino acids, etc.) was evident from FTIR spectra of fibers at 10, 14, 17, and 20 dpa (day postanthesis). The vibration corresponding to the noncellulosic compounds disappeared at 36 dpa. Furthermore, independent TGA analysis supported the results obtained with FTIR, showing that the transition from primary cell wall synthesis to secondary cell wall synthesis occurs at or around 20 dpa. This study is the first to report on the use of the UATR-FTIR and TGA to elucidate structural changes during cotton fiber development. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Fourier Transform Infrared microscopy (FTIR) has become an essential analytical tool available to scientists to study various materials. Specifically FTIR has been increasingly used to study cell wall developments in plants, investigate the efficiency of the surface modification of polymers, identifying contaminants, and predicting the physical properties of certain polymers and biopolymers, etc. This chapter reviews some selected application of the FTIR to study cellulose development in cotton fibers and to predict cotton fiber physical properties. Cotton fiber maturity is a major yield component and an important fiber quality trait that is directly linked to the quantity of cellulose deposited during the secondary cell wall (SCW) biogenesis. Cotton fiber development consists of five major overlapping stages: differentiation, initiation, polar elongation, secondary cell wall development, and maturation. The transition period between 16 and 21 dpa (days post anthesis) is regarded to represent a major developmental stage between the primary cell wall and the SCW. Fourier Transform Infrared spectroscopy was used to investigate the structural changes that occur during the different developmental stages. The IR spectra of fibers harvested at different stages of development (10, 14, 17, 18, 19, 20, 21, 24, 27, 30, 36, 46, and 56 dpa) show the presence of vibrations located at 1,733 cm-1 (C=O stretching originating from esters or amides) and 1,534 cm-1 (NH2 deformation corresponding to proteins or amino acids). The results converge towards the conclusion that the transition phase between the primary cell wall and the secondary cell wall occurs between 17 and 18 dpa in fibers from TX19 cultivar, while this transition occurs between 21 and 24 dpa in fibers from TX55 cultivar. The Universal Attenuated Total Reflectance FTIR (UATR-FTIR) was used to evaluate the cotton fiber properties. One hundred and four cotton samples were selected. Thirty FTIR spectra were acquired from each sample and analyzed. Partial Least Square (PLS) analysis of the FTIR spectra was performed and the results showed that micronaire and surface area (calculated from the AFIS data) could be predicted from the FTIR measurements with very high coefficients of determination. However, the prediction of fiber maturity is probably not possible with the UATR-FTIR. It was concluded that, to be able to predict the fiber maturity with the FTIR, it would be necessary to perform the measurements in the transmission mode rather than in the reflectance mode.

In this study, cotton fabric was successfully modified by titania nanosols prepared by means of the sol-gel process with tetrabutyl orthotitanate [Ti(OC(4)H(9))(4)] as the active ingredient. The cotton fabric was padded with the nanosol solution, dried at 60 degrees C, and cured at 150 degrees C. Scanning electron microscopy showed the presence of a titania film on the fiber surface. The photocatalytic properties of titania-nanosol-treated cotton fabric were investigated. The results showed that stains of coffee and red wine were successfully decomposed by exposure of the stained fabric to UV radiation. Furthermore, titania-nanosol treatment imparted to the cotton fabric a very good protection against UV radiation. The durability of the treatment was investigated by performing repeated home laundering, and the results showed no effect of laundering on the UV-protection efficiency.