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1.
Environ Res ; 204(Pt A): 112029, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34509486

RESUMEN

Pb(II) is a heavy metal that is a prominent contaminant in water contamination. Among the different pollution removal strategies, adsorption was determined to be the most effective. The adsorbent and its type determine the adsorption process's efficiency. As part of this effort, a magnetic reduced graphene oxide-based inverse spinel nickel ferrite (rGNF) nanocomposite for Pb(II) removal is synthesized, and the optimal values of the independent process variables (like initial concentration, pH, residence time, temperature, and adsorbent dosage) to achieve maximum removal efficiency are investigated using conventional response surface methodology (RSM) and artificial neural networks (ANN). The results indicate that the initial concentration, adsorbent dose, residence time, pH, and process temperature are set to 15 mg/L, 0.55 g/L, 100 min, 5, and 30 °C, respectively, the maximum removal efficiency (99.8%) can be obtained. Using the interactive effects of process variables findings, the adsorption surface mechanism was examined in relation to process factors. A data-driven quadratic equation is derived based on the ANOVA, and its predictions are compared with ANN predictions to evaluate the predictive capabilities of both approaches. The R2 values of RSM and ANN predictions are 0.979 and 0.991 respectively and confirm the superiority of the ANN approach.


Asunto(s)
Nanocompuestos , Contaminantes Químicos del Agua , Adsorción , Óxido de Aluminio , Compuestos Férricos , Grafito , Cinética , Plomo , Óxido de Magnesio , Níquel , Contaminantes Químicos del Agua/análisis
2.
Environ Res ; 204(Pt D): 112359, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34774834

RESUMEN

Removing decolorizing acid blue 113 (AB113) dye from textile wastewater is challenging due to its high stability and resistance to removal. In this study, we used an artificial neural network (ANN) model to estimate the effect of five different variables on AB113 dye removal in the sonophotocatalytic process. The five variables considered were reaction time (5-25 min), pH (3-11), ZnO dosage (0.2-1.0 g/L), ultrasonic power (100-300 W/L), and persulphate dosage (0.2-3 mmol/L). The most effective model had a 5-7-1 architecture, with an average deviation of 0.44 and R2 of 0.99. A sensitivity analysis was used to analyze the impact of different process variables on removal efficiency and to identify the most effective variable settings for maximum dye removal. Then, an imaginary sonophotocatalytic system was created to measure the quantitative impact of other process parameters on AB113 dye removal. The optimum process parameters for maximum AB 113 removal were identified as 6.2 pH, 25 min reaction time, 300 W/L ultrasonic power, 1.0 g/L ZnO dosage, and 2.54 mmol/L persulfate dosage. The model created was able to identify trends in dye removal and can contribute to future experiments.


Asunto(s)
Compuestos Azo , Redes Neurales de la Computación , Textiles , Aguas Residuales
3.
Environ Res ; 203: 111846, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34364860

RESUMEN

Arsenic contamination is a global problem, as it affects the health of millions of people. For this study, data-driven artificial neural network (ANN) software was developed to predict and validate the removal of As(V) from an aqueous solution using graphene oxide (GO) under various experimental conditions. A reliable model for wastewater treatment is essential in order to predict its overall performance and to provide an idea of how to control its operation. This model considered the adsorption process parameters (initial concentration, adsorbent dosage, pH, and residence time) as the input variables and arsenic removal as the only output. The ANN model predicted the adsorption efficiency with high accuracy for both training and testing datasets, when compared with the available response surface methodology (RSM) model. Based on the best model synaptic weights, user-friendly ANN software was created to predict and analyze arsenic removal as a function of adsorption process parameters. We developed various graphical user interfaces (GUI) for easy use of the developed model. Thus, a researcher can efficiently operate the software without an understanding of programming or artificial neural networks. Sensitivity analysis and quantitative estimation were carried out to study the function of adsorption process parameter variables on As(V) removal efficiency, using the GUI of the model. The model prediction shows that the adsorbent dosages, initial concentration, and pH are the most influential parameters. The efficiency was increased as the adsorbent dosages increased, decreasing with initial concentration and pH. The result show that the pH 2.0-5.0 is optimal for adsorbent efficiency (%).


Asunto(s)
Arsénico , Contaminantes Químicos del Agua , Adsorción , Humanos , Concentración de Iones de Hidrógeno , Cinética , Redes Neurales de la Computación , Programas Informáticos , Contaminantes Químicos del Agua/análisis
4.
Environ Res ; 197: 111107, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33812876

RESUMEN

Celestite and barite formation results in contamination of barium and strontium ions hinder oilfield water purification. Conversion of bio-waste sorbent products deals with a viable, sustainable and clean remediation approach for removing contaminants. Biochar sorbent produced from rice straw was used to remove barium and strontium ions of saline water from petroleum industries. The removal efficiency depends on biochar amount, pH, contact time, temperature, and Ba/Sr concentration ratio. The interactions and effects of these parameters with removal efficiency are multifaceted and nonlinear. We used an artificial neural network (ANN) model to explore the correlation between process variables and sorption responses. The ANN model is more accurate than that of existing kinetic and isotherm equations in assessing barium and strontium removal with adj. R2 values of 0.994 and 0.991, respectively. We developed a standalone user interface to estimate the barium and strontium removal as a function of sorption process parameters. Sensitivity analysis and quantitative estimation were carried out to study individual process variables' impact on removal efficiency.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Bario , Concentración de Iones de Hidrógeno , Cinética , Aguas Salinas , Estroncio
5.
Environ Res ; 199: 111370, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34043971

RESUMEN

Heavy metal ions in aqueous solutions are taken into account as one of the most harmful environmental issues that ominously affect human health. Pb(II) is a common pollutant among heavy metals found in industrial wastewater, and various methods were developed to remove the Pb(II). The adsorption method was more efficient, cheap, and eco-friendly to remove the Pb(II) from aqueous solutions. The removal efficiency depends on the process parameters (initial concentration, the adsorbent dosage of T-Fe3O4 nanocomposites, residence time, and adsorbent pH). The relationship between the process parameters and output is non-linear and complex. The purpose of the present study is to develop an artificial neural networks (ANN) model to estimate and analyze the relationship between Pb(II) removal and adsorption process parameters. The model was trained with the backpropagation algorithm. The model was validated with the unseen datasets. The correlation coefficient adj.R2 values for total datasets is 0.991. The relationship between the parameters and Pb(II) removal was analyzed by sensitivity analysis and creating a virtual adsorption process. The study determined that the ANN modeling was a reliable tool for predicting and optimizing adsorption process parameters for maximum lead removal from aqueous solutions.


Asunto(s)
Nanocompuestos , Contaminantes Químicos del Agua , Adsorción , Compuestos Férricos , Humanos , Concentración de Iones de Hidrógeno , Cinética , Plomo , Redes Neurales de la Computación , Soluciones , Contaminantes Químicos del Agua/análisis
6.
Natl Med J India ; 25(4): 230-3, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23278784

RESUMEN

BACKGROUND: Availability of doctors at primary health centres (PHCs) is a major concern. We measured the operational availability of doctors in PHCs and examined the effect of residential distance and private practice. METHODS: Thirty-six health centres, consisting of six randomly selected PHCs from six purposively chosen districts in Andhra Pradesh were studied. Cross-sectional data on residential distance, private practice and attendance pattern of 38 operationally available medical officers were analysed. RESULTS: About 80% of doctors residing within 20 km attended their PHC on all 6 days of a week, compared with only 33% for those staying >40 km away. Among those staying >20 km away from their PHC, the odds of absenteeism by privately practising doctors was 3-24 times more than for those not practising privately. CONCLUSION: Residential distance seems to affect the operational availability of doctors. Private practice by doctors living within 20 km from the PHC does not seem to affect their operational availability. However, private practice by doctors staying >20 km away from their PHC may affect their availability.


Asunto(s)
Absentismo , Instituciones de Atención Ambulatoria , Médicos/provisión & distribución , Atención Primaria de Salud , Estudios Transversales , Humanos , India , Práctica Privada , Características de la Residencia , Recursos Humanos
7.
Sci Total Environ ; 787: 147624, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34000535

RESUMEN

The efficiency of heavy metal in biofilm reactors depends on absorption process parameters, and those relationships are complicated. This study explores artificial neural networks (ANNs) feasibility to correlate the biofilm reactor process parameters with absorption efficiency. The heavy metal removal and turbidity were modeled as a function of five process parameters, namely pH, temperature(°C), feed flux(ml/min), substrate flow(ml/min), and hydraulic retention time(h). We developed a standalone ANN software for predicting and analyzing the absorption process in handling industrial wastewater. The model was tested extensively to confirm that the predictions are reasonable in the context of the absorption kinetics principles. The model predictions showed that the temperature and pH values are the most influential parameters affecting absorption efficiency and turbidity.


Asunto(s)
Metales Pesados , Purificación del Agua , Biopelículas , Reactores Biológicos , Eliminación de Residuos Líquidos , Aguas Residuales
8.
Chemosphere ; 268: 129345, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33360146

RESUMEN

This study shows an artificial neural network (ANN) model of chlorophenol rejection from aqueous solutions and predicting the performance of spiral wound reverse osmosis (SWRO) modules. This type of rejection shows complex non-linear dependencies on feed pressure, feed temperature, concentration, and feed flow rate. It provides a demanding test of the application of ANN model analysis to SWRO modules. The predictions are compared with experimental data obtained with SWRO modules. The overall agreement between the experimental and ANN model predicted was almost 99.9% accuracy for the chlorophenol rejection. The ANN model approach has the advantage of understanding the complex chlorophenol rejection phenomena as a function of SWRO process parameters.


Asunto(s)
Clorofenoles , Purificación del Agua , Filtración , Membranas Artificiales , Ósmosis
9.
J Nanosci Nanotechnol ; 20(11): 7119-7123, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-32604568

RESUMEN

Owing to the speculated price hike and scarcity of lithium resources, sodium-ion batteries are attracting significant research interest these days. However, sodium-ion battery anodes do not deliver good electrochemical performance, particularly rate performance. Herein, we report the facile electrospinning synthesis of a free-standing nickel disulfide (NiS²) embedded on carbon nanofiber. This electrode did not require a conducting agent, current collector, and binder, and typically delivered high capacity and rate performance. The electrode delivered a high initial capacity of 603 mAh g-1 at the current density of 500 mA g-1. Moreover, the electrode delivered the capacity of 271 mAh g-1 at the high current density of 15 A g-1. The excellent rate performance and high coulombic efficiency of the electrode were attributed to its low charge transfer resistance and unique structure.

10.
Mol Cell Biol ; 7(11): 3929-36, 1987 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3481036

RESUMEN

The eucaryotic elongation factor Tu (eEF-Tu) is a single polypeptide with an approximate Mr of 53,000. During protein synthesis eEF-Tu promotes the binding of aminoacyl-tRNA to the ribosome. To study the expression of the gene(s) for this factor, a genomic clone was isolated that contains a mouse eEF-Tu gene. We screened a phage genomic library with a synthetic oligonucleotide probe complementary to a region of the Saccharomyces cerevisiae and Artemia sp. eEF-Tu genes which codes for an area that is highly conserved between both yeast and Artemia sp. eEF-Tu. From approximately 75,000 phage plaques we obtained five isolates with apparently identical inserts. All five clones contained a 3.8-kilobase EcoRI fragment that hybridized to additional oligonucleotide probes corresponding to different conserved regions of eEF-Tu. We sequenced the 5' end of one genomic clone and determined the length of the cloned fragment that was protected by eEF-Tu mRNA in S1 nuclease protection assays. A quantitative S1 nuclease protection assay was used to compare the relative steady-state levels of eEF-Tu mRNA in total mRNA in total RNA isolated from hexamethylene-bisacetamide-induced murine erythroleukemia cells. The results show a dramatic reduction in the steady-state level of eEF-Tu mRNA as differentiation proceeds. A similar reduction in transcription of eEF-Tu mRNA was observed in isolated nuclei. Finally, we examined the in vivo synthesis of eEF-Tu during differentiation and found that it declined in a manner parallel to the decline in the steady-state level of eEF-Tu mRNA. In addition, we have isolated and sequenced a cDNA clone for mouse eEF-Tu. The derived amino acid sequence is compared with sequences from other eucaryotes.


Asunto(s)
Genes , Leucemia Eritroblástica Aguda/genética , Leucemia Experimental/genética , Factor Tu de Elongación Peptídica/genética , Transcripción Genética , Animales , Secuencia de Bases , Diferenciación Celular , Línea Celular , Núcleo Celular/metabolismo , Clonación Molecular , Codón , Leucemia Experimental/patología , Ratones , Datos de Secuencia Molecular , Peso Molecular , ARN Mensajero/genética , ARN Mensajero/aislamiento & purificación
11.
Kathmandu Univ Med J (KUMJ) ; 5(3): 414-6, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18604067

RESUMEN

Penetrating neck wounds are potentially dangerous and require emergency management because of the presence of vital structures in the neck. Organic foreign bodies further carries a risk of wound infection. We present a case of penetrating broken branch of a tree traversing from zone II to zone III without any neurovascular injury. Neck exploration was done with midline mandibulotomy approach and foreign body was removed without any complication.


Asunto(s)
Cuerpos Extraños/cirugía , Traumatismos del Cuello/cirugía , Plantas , Heridas Penetrantes/cirugía , Accidentes por Caídas , Niño , Femenino , Humanos
12.
Int J Biol Macromol ; 85: 227-37, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26723248

RESUMEN

Enzyme immobilization is an important technique to enhance stability, storability and reusability of enzymes. In the present work, pine needles, a forest bio-waste, were used as a feedstock of cellulose to synthesize new materials as supports for immobilization of α-chymotrypsin (CT) enzyme. The extracted cellulose from pine needles was etherified with different alkyl bromides (RBr) and etherified products were further modified to dialdehyde via oxidation with NaIO4 to get the desired products, dialdehyde cellulose ethers (ROcellCHO). CT was then covalently immobilized onto as-synthesized dialdehyde cellulose ethers via Schiff-base formation, i.e., imine linkage. The synthesized products and enzyme immobilization were confirmed by different characterization techniques and the activity assay of the free and the immobilized CT was carried out using standard protocol with variation of different parameters such as temperature, pH and substrate concentration. The storage stability and reusability of the immobilized CT were also investigated. CT activity was also studied in simulated physiological conditions in the artificial gastric fluid and artificial intestinal fluid. Artificial neural network (ANN) model was employed to correlate the relationship with% relative activity and time, temperature and pH affecting enzyme activity. A good correlation of experimental data was predicted by ANN model.


Asunto(s)
Celulosa/análogos & derivados , Quimotripsina/química , Enzimas Inmovilizadas , Algoritmos , Celulosa/química , Celulosa/ultraestructura , Estabilidad de Enzimas , Éteres , Concentración de Iones de Hidrógeno , Iminas/química , Redes Neurales de la Computación , Bases de Schiff/química , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Difracción de Rayos X
13.
Gene ; 70(2): 231-43, 1988 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-3215517

RESUMEN

Eukaryotic protein synthesis initiation factor 4A (eIF-4A), a 46-kDa polypeptide, is involved both in mRNA cap recognition and in the binding of mRNA to 40S ribosomal subunits. A 41-mer oligodeoxynucleotide probe was synthesized complementary to a portion of the published coding sequence of eIF-4A mRNA [Nielsen et al., Nucleic Acids Res. 13 (1985) 6867-6870] and used to screen a mouse genomic library. We have isolated and characterized a full-length clone from that library. The eIF-4A sequence is contained in eleven exons. The eleventh exon also has the 3'-nontranslated sequence and two separate polyadenylation sites. Northern-blot analysis of mouse poly(A)+RNA indicates that there are several distinct mRNA species coding for eIF-4A. Two of these contain the same coding sequence and differ only in the length of the 3'-nontranslated region. Two of the eIF-4A mRNAs are therefore likely to be the result of differential processing at the 3'-end. We have used a fragment of the genomic clone to measure the steady-state levels of eIF-4A mRNA during the induced differentiation of murine erythroleukemia cells. S1 nuclease protection experiments demonstrated that by the fourth day after induction eIF-4A mRNA declined to 25% of its steady-state level in uninduced cells. In contrast, the steady-state level of beta-globin mRNA increased dramatically during differentiation. In vitro transcription assays using nuclei isolated from uninduced and induced cells show that the rate of transcription of eIF-4A mRNA was 40% greater in differentiated cells, indicating a posttranscriptional component is involved in the regulation of the steady-state mRNA level.


Asunto(s)
Eritrocitos/citología , Regulación de la Expresión Génica , Factores de Iniciación de Péptidos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Diferenciación Celular , Núcleo Celular/fisiología , Clonación Molecular , Factor 4A Eucariótico de Iniciación , Exones , Genes , Datos de Secuencia Molecular , Sondas de Oligonucleótidos/síntesis química , ARN Mensajero/biosíntesis , Mapeo Restrictivo , Células Tumorales Cultivadas
14.
Int J Med Sci ; 1(3): 152-164, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15912194

RESUMEN

Osteoporosis is characterized by decreased bone mineral density and mechanistic imbalances of bone tissue that may result in reduced skeletal strength and an enhanced susceptibility to fractures. Osteoporosis in its most common form affects the elderly (both sexes) and all racial groups of human beings. Multiple environmental risk factors like acquired immune deficiency syndrome (AIDS) are believed to be one of the causes of osteoporosis. Recently a high incidence of osteoporosis has been observed in human immunodeficiency virus (HIV) infected individuals. The etiology of this occurrence in HIV infections is controversial. This problem seems to be more frequent in patients receiving potent antiretroviral therapy. In AIDS, the main suggested risk factors for the development of osteoporosis are use of protease inhibitors, longer duration of HIV infection, lower body weight before antiretroviral therapy, high viral load. Variations in serum parameters like osteocalcin, c-telopeptide, levels of elements like Calcium, Magnesium, Phosphorus, concentration of vitamin-D metabolites, lactate levels, bicarbonate concentrations, amount of alkaline phosphatase are demonstrated in the course of development of osteoporosis. OPG/RANKL/RANK system is final mediator of bone remodeling. Bone mineral density (BMD) test is of added value to assess the risk of osteoporosis in patients infected with AIDS. The biochemical markers also aid in this assessment. Clinical management mostly follows the lines of treatment of osteoporosis and osteopenia.

15.
Theriogenology ; 52(4): 701-7, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10734367

RESUMEN

This study was conducted to compare fertilization rate and viable embryo recovery rate in superovulated buffalo (n = 64) following insemination with semen from buffalo bulls (n = 5) having different fertility rates as determined by AI. Frozen-thawed semen from fertile bulls with similar post-thaw progressive motility and sperm morphology was used to inseminate buffalo at superovulatory estrus. Fertilization and viable embryo recovery rates differed among bulls, but this bull-specific effect was not related to the overall herd fertility rate as determined by AI in normal cyclic animals. These results indicate that individual bulls differ in their contribution to fertilization of superovulated donors and also to embryonic development, as determined by viable embryo recovery. Moreover, the results also suggest that buffalo bulls can be screened for optimal fertility and embryo recovery rates in superovulated donors. Further studies are warranted to ascertain the factors which contribute to such bull-specific effects.


Asunto(s)
Búfalos/fisiología , Fertilización , Superovulación , Animales , Criopreservación/veterinaria , Estro , Femenino , Inseminación Artificial/veterinaria , Masculino , Embarazo , Preservación de Semen/veterinaria
16.
Theriogenology ; 52(1): 1-10, 1999 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-10734401

RESUMEN

The objectives of this study were to determine the pregnancy rate and factors affecting it following nonsurgical embryo transfer in buffalo. Donor buffalo were superovulated with FSH, and embryos collected nonsurgically were evaluated for stage of development and quality. They were transferred nonsurgically to 91 recipients on Days 5 to 7 of the natural (n = 52) or induced (n = 39) estrus (estrus = Day 0). The overall pregnancy rate of 24/91(26.4%) was higher than in earlier reports for buffalo but was much lower than in cattle. Pregnancy rates were not affected by season (autumn vs winter), side of transfer (right vs left uterine horn), or type of estrus (spontaneous vs induced). The pregnancy rate was high 11/27(40.7%) when donors and recipients were closely synchronized, while it was compromised when recipients were in estrus at +12 h (1/7, 14.3%) and at -12 h (5/27, 18.5%). Asynchrony beyond 12 h on either side resulted into conception failure. The pregnancy rate tended to increase with the increase in CL size of recipients, while stage of embryonic development had no effect. The transfer of an 8-cell embryo with a 16-cell embryo led to the birth of heterosexual twins, indicating that the uterine milieu of Day 5 to 6 recipients may be tolerated by the out-of-phase 8-cell embryo, at least in the presence of a more mature embryo. Embryo quality had the greatest effect on pregnancy rate as it was higher (P < 0.005) after the transfer of Grade I than Grade III embryos (6/10, 60.0% vs 3/36, 13.9%). Assessment of returns to estrus indicated that among nonpregnant recipients, 17/67 (25.4%) embryos never matured sufficiently to prevent luteolysis through maternal recognition of pregnancy (MRP), while 14/67 (20.8%) embryos probably died following MRP. These results indicate that efforts to increase pregnancy rate following embryo transfer in buffalo should include prevention of luteolysis during the first week of transfer and a reduction in the incidence of embryonic mortality.


Asunto(s)
Búfalos , Transferencia de Embrión/veterinaria , Animales , Bovinos , Estro , Sincronización del Estro , Femenino , Hormona Folículo Estimulante/administración & dosificación , Embarazo , Estudios Retrospectivos , Estaciones del Año , Superovulación
17.
Int J Gynaecol Obstet ; 30(3): 279-81, 1989 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2575057

RESUMEN

A 35-year-old parous woman was treated with abdominal hysterectomy for uterine myomata. The patient developed intussusception in the immediate postoperative period and was managed by laparotomy and manual reduction. The difficulties in diagnosis and management of this rare complication are discussed.


Asunto(s)
Histerectomía , Enfermedades del Íleon/etiología , Intususcepción/etiología , Complicaciones Posoperatorias/etiología , Adulto , Femenino , Humanos , Enfermedades del Íleon/diagnóstico , Enfermedades del Íleon/terapia , Intususcepción/diagnóstico , Intususcepción/terapia , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/terapia
18.
Int J Gynaecol Obstet ; 28(1): 77-8, 1989 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2565836

RESUMEN

A 25-year-old parous woman was treated with radical hysterectomy for cancer of the cervix. Six months later she developed a vesico-vaginal fistula following coitus. The fistula was repaired and vaginal reconstruction performed. Sexual dysfunction and the need for vaginal reconstruction are discussed.


Asunto(s)
Coito , Complicaciones Posoperatorias , Neoplasias del Cuello Uterino/cirugía , Fístula Vesicovaginal/etiología , Adulto , Femenino , Humanos
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