Evaluation of the Morphological Effects of Hydroxyapatite Nanoparticles on the Rheological Properties and Printability of Hydroxyapatite/Polycaprolactone Nanocomposite Inks and Final Scaffold Features.

This study is focused on the importance of nanohydroxyapatite (nHA) particle morphology with the same particle size range on the rheological behavior of polycaprolactone (PCL) composite ink with nHA as a promising candidate for additive manufacturing technologies. Two different physiologic-like nHA morphologies, that is, plate and rod shape, with particles size less than 100 nm were used. nHA powders were well characterized and the printing inks were prepared by adding the different ratios of nHA powders to 50% w/v of PCL solution (nHA/PCL: 35/65, 45/55, 55/45, and 65/35 w/w%). Subsequently, the influence of nHA particle morphology and concentration on the printability and rheological properties of composite inks was investigated. HA nanopowder analysis revealed significant differences in their microstructural properties, which affected remarkably the composite ink printability in several ways. For instance, adding up to 65% w/w of plate-like nHA to the PCL solution was possible, while nanorod HA could not be added above 45% w/w. The printed constructs were successfully fabricated using the extrusion-based printing method and had a porous structure with interconnected pores. Total porosity and surface area increased with nHA content due to the improved fiber stability following deposition of material ink. Consequently, degradation rate and bioactivity increased, while compressive properties decreased. While nanorod HA particles had a more significant impact on the mechanical strength than plate-like morphology, the latter showed less crystalline order, which makes them more bioactive than nanorod HA. It is therefore important to note that the nHA microstructure broadly affects the printability of printing ink and should be considered according to the intended biomedical applications.

Pathogenic and therapeutic roles of cytokines in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a heterogeneous disease with high mortality that accounts for the most common acute leukemia in adults. Despite all progress in the therapeutic strategies and increased rate of complete remission, many patients will eventually relapse and die from the disease. Cytokines as molecular messengers play a pivotal role in the immune system. The imbalance release of cytokine has been shown to exert a significant influence on the progression of hematopoietic malignancies including acute myeloid leukemia. This article aimed to summarize current knowledge about cytokines and their critical roles in the pathogenesis, treatment, and survival of AML patients.

Fabrication of a sensitive colorimetric nanosensor for determination of cysteine in human serum and urine samples based on magnetic-sulfur, nitrogen graphene quantum dots as a selective platform and Au nanoparticles.

A novel colorimetric nanosensor is reported for the selective and sensitive determination of cysteine using magnetic-sulfur, nitrogen graphene quantum dots (Fe3O4/S, N-GQDs), and gold nanoparticles (Au NPs). Thus, S, N-GQDs was firstly immobilized on Fe3O4 nanoparticles through its magnetization in the presence of Fe3+ in the alkali solution. The prepared Fe3O4/S, N-GQDs were dispersed in cysteine solution resulting in its quick adsorption on the surface of the Fe3O4/S, N-GQDs through hydrogen bonding interaction. Then, Au NPs solution was added to this mixture that after a short time, the color of Au NPs changed from red to blue, the intensity of surface plasmon resonance peak of Au NPs at 530 nm decreased, and a new peak at a higher wavelength of 680 nm appeared. The effective parameters on cysteine quantification were optimized via response surface methodology using the central composite design. Under optimum conditions, the absorbance ratio (A680/A530) has a linear proportionality with cysteine concentration in the range of 0.04-1.20 µmol L-1 with a limit of detection of 0.009 µmol L-1. The fabrication of the reported nanosensor is simple, fast, and is capable of efficient quantification of ultra traces of cysteine in human serum and urine real samples.

Design of a pseudo stir bar sorptive extraction using graphenized pencil lead as the base of the molecularly imprinted polymer for extraction of nabumetone.

Molecularly imprinted polymer (MIP) was synthesized through the coprecipitation method on the graphene oxide anchored pencil lead as a substrate for the first time and applied as an efficient sorbent for pseudo stir bar sorptive extraction of nabumetone. The extracted analyte was determined by a novel spectrophotometric method based on the aggregation of silicate sol-gel stabilized silver nanoparticles in the presence of the analyte. The synthesized polymer was characterized using Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Optimization of important parameters affecting the extraction efficiency was done using central composite design whereas the spectrophotometric method was optimized via one at a time variable. Under the optimal conditions, the calibration curve exhibited linearity in the concentration range of 1.5-20.0 µg L-1. A limit of detection of 0.20 µg L-1, an enhancement factor of 393 and relative standard deviations (at 10 µg L-1, n = 6) of 4.6% and 8.1% for intra- and inter-day analysis were obtained. The developed procedure was successfully utilized for the quantification of traces of nabumetone in tap water and biological samples with the complex matrix including human urine and serum.

Selective fluorometric determination of sulfadiazine based on the growth of silver nanoparticles on graphene quantum dots.

A sensitive fluorometric assay is described for the direct determination of the antibiotic sulfadiazine. Silver nanoparticles placed on graphene quantum dots (Ag NP-GQDs) were synthesized by reduction of AgNO3 with sodium borohydride in the presence of GQDs. The growth of Ag NPs on the surface of the GQDs causes quenching of the blue fluorescence of the GQDs with an emission maximum at 470 nm by surface-enhanced energy transfer. If sulfadiazine is added, it interacts with Ag NPs and fluorescence is restored. Under optimal conditions, the fluorescence increases linearly in the sulfadiazine concentration range of 0.04-22.0 µM. The detection limit is 10 nM with relative standard deviations of 2.3 and 4.2 (at 10 µM of sulfadiazine; for n = 6) for intra- and inter-day assays. Graphical abstractSchematic representation of sulfadiazine determination using Ag NP-GQDs as a fluorescent nanoprobe.

A turn-on graphene quantum dot and graphene oxide based fluorometric aptasensor for the determination of telomerase activity.

A turn-on fluorometric assay is described for determination of the activity of enzyme telomerase. For this purpose, graphene quantum dots (GQDs) were first modified with the telomeric sequence (5'-amino-AATCCGTCGAGCAGAGTT-3') via a condensation reaction. Injection of graphene oxide causes instant quenching of the blue fluorescence of the GQDs. Addition of cell extract containing telomerase, triggers the extension of telomer via addition of specific sequence (TTAGGG)n to its 3' end. Fluorescence, best measured at excitation/emission wavelengths of 390/446 nm, is subsequently restored due to folding of the extended telomeric sequence into G-quadruplex structure. The method was applied to the determination of telomerase activity in crude cell extracts of as little as 10 HeLa cells. The linear dynamic range extends from 10 to 6500 cells. Graphical abstractIn this study, a new turn-on graphene quantum dotm and graphene oxide based fluorometric assay is developed for the determination of telomerase activity.

Gradient extractive phase prepared by controlled rate infusion method: An applicable approach in solid phase microextraction for non-targeted analysis.

The aim of this study is to introduce an extractive phase based on gradient concept by continuous changing in chemical functional groups for non-targeted analysis. For this purpose, three different two-component coatings containing (3-aminopropyl)trimethoxysilane (APTES) as polar and either phenyltriethoxysilane (PTES), octyl-trimethoxysilane (OTMS) or methyltrimethoxysilane (MTMS) as nonpolar precursors were formed on the modified stainless steel wires using controlled rate infusion (CRI) method. The presence of polar and/or non-polar functional groups on the surface of substrate was evaluated by Fourier-transform infrared spectroscopy (FTIR) together with contact angles determined alongside the gradient surface. The morphology and thickness of the prepared fibers were also investigated by scanning electron microscopy (SEM). Furthermore, uniform single-component fibers from polar (APTES) and nonpolar (PTES) coatings were fabricated in order to be compared with the gradient sorbent. The gradient phase was implemented as a fiber coating in headspace- or immersed-solid phase microextraction of various compounds including chlorobenzenes, polycyclic aromatic hydrocarbons, chlorophenols and volatile organic compounds (Log Kow range: -0.77 to 4.64). Under the optimized condition, the limits of detection and quantification were obtained in the range of 0.01-0.5 µg L-1 and 0.05-1.5 µg L-1, respectively. The intra-day and inter-day relative standard deviations of 2-10% and 11-17% were achieved, respectively. The method was successfully applied to the extraction of VOCs from real water sample and relative recoveries were between 89 and 105%. The capability and efficiency of the gradient coating appears to be quite appropriate for non-targeted analysis.

Synthesis, characterization, and application of a Zn (II)-imprinted polymer grafted on graphene oxide/magnetic chitosan nanocomposite for selective extraction of zinc ions from different food samples.

A novel Zn(II) imprinted polymer was synthesized via a co-precipitation method using graphene oxide/magnetic chitosan nanocomposite as supporting material. The synthesized imprinted polymer was characterized by Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM) and applied as a sorbent for selective magnetic solid phase extraction of zinc followed by its determination by flame atomic absorption spectrometry. The kinetic and isothermal adsorption experiments were carried out and all parameters affecting the extraction process was optimized. Under the optimal experimental conditions, the developed procedure exhibits a linear dynamic range of 0.5-5.0µgL-1 with a detection limit of 0.09µgL-1 and quantification limit of 0.3µgL-1. The maximum sorption capacity of the sorbent was found to be 71.4mgg-1. The developed procedure was successfully applied to the selective extraction and determination of zinc in various samples including well water, drinking water, black tea, rice, and milk.

The effect of a self-care program based on the teach back method on the postpartum quality of life.

BACKGROUND: The postpartum period is a critical stage of life with major changes in the quality of life. Therefore, special consideration is needed to this issue. OBJECTIVE: To determine the effect of a self-care program based on the Teach Back method on the postpartum quality of life. METHODS: This experimental study was conducted on eighty postpartum women who had given birth in health centers across Darreh Shahr County, Ilam Province, Iran in 2016. The control group received only routine postpartum care according to the national guidelines. The trial group received the routine care in addition to two sessions of physical and psychological postpartum self-care based on the Teach Back method. The two groups were assessed in terms of their quality of life before and after the intervention using the Postpartum Quality of Life Questionnaire. The data were analyzed using SPSS version 21. Descriptive statistic tests, Chi squared, independent-samples t-test, paired-samples t-test, Wilcoxon and Mann Whitney's test was used. RESULTS: Before the intervention, the postpartum quality of life score was 106.23±11.866 in the trial group and 107.30±13.197 in the control group; after the intervention, the score was 124.73±10.706 and 115.03±12.687 in the two groups respectively, suggesting a significant inter-group difference after the intervention (p<0.001). Significant differences were also observed between the two groups in terms of the mother's feelings toward herself, toward her child and toward her spouse and others, and physical health before and after the intervention (p<0.001). CONCLUSIONS: Using the Teach Back model for a self-care program appears to dramatically improve the postpartum quality of life and is therefore recommended as a useful method for postpartum care. TRIAL REGISTRATION: The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT2015012820854N1. FUNDING: The authors received no financial support for the research, authorship, and/or publication of this article.

Indirect spectrophotometric determination of sulfadiazine based on localized surface plasmon resonance peak of silver nanoparticles after cloud point extraction.

A novel, efficient, easy to use, environmentally friendly and cost-effective methodology is developed for the indirect spectrophotometric determination of sulfadiazine in different samples. The method is based on the micelle-mediated extraction of silver sulfadiazine and converting the silver content of the resultant surfactant-rich phase to the silver nanoparticles via generation of [Ag(NH3)2]+ followed by its chemical reduction using ascorbic acid. The changes in the amplitude of localized surface plasmon resonance peak of silver nanoparticles as a function of sulfadiazine concentration in the sample solution was monitored using fiber optic linear array spectrophotometry at 457nm. The experimental conditions were thoroughly investigated and optimized. Under the optimized condition, the developed procedure showed dynamic linear calibration within the range of 10.0-800.0µgL-1 with a detection limit of 2.8µgL-1 for sulfadiazine. The relative standard deviation of the method for six replicate measurements at 150.0µgL-1 of sulfadiazine was 4.7%. The developed method was successfully applied to the determination of sulfadiazine in different samples including well water, human urine, milk and pharmaceutical formulation.

Radiation-induced non-targeted effect in vivo: Evaluation of cyclooygenase-2 and endothelin-1 gene expression in rat heart tissues.

AIM: In this study, we investigated expression levels of cyclooxygenase-2 (COX-2) and endothelin-1 (ET-1) genes after pelvis and heart irradiation in a rat model. These factors are involved in heart diseases (HDs). MATERIALS AND METHODS: We used seven groups, including two groups of pelvic irradiation, two groups of whole body irradiation, two groups of heart irradiation, and one control nonirradiated group. Pelvis irradiations were conducted at a 2 cm × 2 cm in the pelvis area. Irradiation condition conducted using 1.25 MeV cobalt-60 gamma-rays (30 cGy/min). The changes at ET-1 and COX-2 gene expressions in heart tissue after pelvis and heart irradiation were measured and compared to the control and whole body irradiation groups at 24 h and 72 h after the exposure. RESULTS: In heart irradiation groups, 3-fold up-regulation of both ET-1 and COX-2 was observed. In pelvis irradiation groups, 3-fold up-regulation of ET-1 was seen, but not significant changes in COX-2 gene expression have observed at distant heart tissues after pelvis irradiation. CONCLUSION: This study reveals that nontargeted effect induced by radiation may be considered as an important phenomenon for induction of HD after radiotherapy.

Application of graphene oxide-silica composite reinforced hollow fibers as a novel device for pseudo-stir bar solid phase microextraction of sulfadiazine in different matrices prior to its spectrophotometric determination.

This study presents a novel, simple and efficient pseudo-stir bar solid phase microextraction method for separation and preconcentration of sulfadiazine. To develop the method, a graphene oxide-silica composite reinforced hollow fiber was prepared via sol-gel technology and used as a novel device to extract sulfadiazine. The retained sulfadiazine was eluted using 180µL of methanol/acetic acid (6:4) and quantified by fiber optic linear array spectrophotometry based on the formation of its azo dye with thenoyltrifluoroacetone. Under optimized conditions, the method exhibited a linear dynamic range of 5-150µgL-1 with a detection limit of 1.5µgL-1 and an enrichment factor of 100. The relative standard deviations of 2.9% and 5.8% (n=6) were obtained at 60µgL-1 level of sulfadiazine for intra- and inter-day analysis respectively. The method was successfully applied to determine sulfadiazine in honey, milk, human urine and environmental water samples.

Development of a novel mixed hemimicelles dispersive micro solid phase extraction using 1-hexadecyl-3-methylimidazolium bromide coated magnetic graphene for the separation and preconcentration of fluoxetine in different matrices before its determination by fiber optic linear array spectrophotometry and mode-mismatched thermal lens spectroscopy.

This study aims at developing a novel, sensitive, fast, simple and convenient method for separation and preconcentration of trace amounts of fluoxetine before its spectrophotometric determination. The method is based on combination of magnetic mixed hemimicelles solid phase extraction and dispersive micro solid phase extraction using 1-hexadecyl-3-methylimidazolium bromide coated magnetic graphene as a sorbent. The magnetic graphene was synthesized by a simple coprecipitation method and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The retained analyte was eluted using a 100 µL mixture of methanol/acetic acid (9:1) and converted into fluoxetine-ß-cyclodextrin inclusion complex. The analyte was then quantified by fiber optic linear array spectrophotometry as well as mode-mismatched thermal lens spectroscopy (TLS). The factors affecting the separation, preconcentration and determination of fluoxetine were investigated and optimized. With a 50 mL sample and under optimized conditions using the spectrophotometry technique, the method exhibited a linear dynamic range of 0.4-60.0 µg L(-1), a detection limit of 0.21 µg L(-1), an enrichment factor of 167, and a relative standard deviation of 2.1% and 3.8% (n = 6) at 60 µg L(-1) level of fluoxetine for intra- and inter-day analyses, respectively. However, with thermal lens spectrometry and a sample volume of 10 mL, the method exhibited a linear dynamic range of 0.05-300 µg L(-1), a detection limit of 0.016 µg L(-1) and a relative standard deviation of 3.8% and 5.6% (n = 6) at 60 µg L(-1) level of fluoxetine for intra- and inter-day analyses, respectively. The method was successfully applied to determine fluoxetine in pharmaceutical formulation, human urine and environmental water samples.

Iron oxide functionalized graphene oxide as an efficient sorbent for dispersive micro-solid phase extraction of sulfadiazine followed by spectrophotometric and mode-mismatched thermal lens spectrometric determination.

A simple and rapid dispersive micro-solid phase extraction (DMSPE) combined with mode-mismatched thermal lens spectrometry as well as fiber optic linear array spectrophotometry was developed for the separation, extraction and determination of sulfadiazine. Graphene oxide was synthesized using the modified Hummers method and functionalized with iron oxide nanoparticles by means of a simple one step chemical coprecipitation method. The synthesized iron oxide functionalized graphene oxide was utilized as an efficient sorbent in DMSPE of sulfadiazine. The retained analyte was eluted by using 180µL of a 6:4 mixture of methanol/acetic acid solution and was spectrophotometrically determined based on the formation of an azo dye through coupling with thenoyltrifluoroacetone. Under the optimized conditions, with the application of spectrophotometry technique and with a sample volume of 100mL, the method exhibited a linear dynamic range of 3-80µg L(-1) with a detection limit of 0.82µg L(-1), an enrichment factor of 200 as well as the relative standard deviations of 2.6% and 4.3% (n=6) at 150µg L(-1) level of sulfadiazine for intra- and inter-day analyses, respectively. Whereas, through the application of the thermal lens spectrometry and a sample volume of 10mL, the method exhibited a linear dynamic range of 1-800µg L(-1) with a detection limit of 0.34µg L(-1) and the relative standard deviations of 3.1% and 5.4% (n=6) at 150µg L(-1) level of sulfadiazine for intra- and inter-day analyses, respectively. The method was successfully applied to the determination of sulfadiazine in milk, honey and water samples.

Brain-Derived Neurotrophic Factor Gene Val66Met Polymorphism and Risk of Schizophrenia: A Meta-analysis of Case-Control Studies.

According to evidences from previous family and association studies, it has been claimed that genetic factors are involved in the neuropathogenesis of Schizophrenia disorder. Whether the Val66Met variant of brain-derived neurotrophic factor (BDNF) gene plays any roles in the pathogenesis of this syndrome or could be a potential biomarker for prognosis of this disorder has been a long-standing controversial issue. We performed a meta-analysis restricted to case-control studies and searched Pubmed, PsychInfo, and Google scholar using keywords including 'association,' 'Val66Met,' 'BDNF,' and 'schizophrenia' published up to May 1, 2015. A total of 39 studies for schizophrenia were combined by fixed- and random-effects models. The pooled results from the schizophrenia sample indicated no significant evidence for the association of Val/Val and Val/Met genotypes of BDNF gene with schizophrenia, but it was observed that there is an association between Met/Met polymorphism and schizophrenia in Asian, European, and Chinese populations, this means that the risk of schizophrenia in Asian, European, and Chinese populations with Met/Met genotype is, respectively, 9, 26, and 9%. There was a significant association between BDNF Val66Met polymorphism and schizophrenia in our meta-analysis study. We cannot rule out the possibility that other polymorphisms in the BDNF gene are involved in the pathophysiology of schizophrenia. In addition, more studies should be conducted on the polymorphisms in other genes to elucidate their possible roles in schizophrenia.

Dispersive solid phase microextraction with magnetic graphene oxide as the sorbent for separation and preconcentration of ultra-trace amounts of gold ions.

A selective, simple and rapid dispersive solid phase microextraction was developed using magnetic graphene oxide (MGO) as an efficient sorbent for the separation and preconcentration of gold ions. The MGO was synthesized by means of the simple one step chemical coprecipitation method, characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Gold ions retained by the sorbent were eluted using 0.5mol L(-)(1) thiourea in 0.1mol L(-1) HCl solution and determined by the flow injection flame atomic absorption spectrometry (FI-FAAS). The factors affecting the separation and preconcentration of gold were investigated and optimized. Under the optimized conditions, the method exhibited a linear dynamic range of 0.02-100.0µg L(-)(1) with a detection limit of 4ng L(-1) and an enrichment factor of 500. The relative standard deviations of 3.2% and 4.7% (n=6) were obtained at 20µg L(-1) level of gold ions for the intra and the inter day analysis, respectively. The method was successfully applied to the determination of gold ions in water and waste water samples as well as a certified reference material (CCU-1b, copper flotation concentrate).

Predicting of trend of hemoglobin a1c in type 2 diabetes: a longitudinal linear mixed model.

BACKGROUND: There are some evidences that control the blood sugar decreasing the risk of diabetes complications, and even fatal. There are so many studies, but they are mostly cross-sectional and ignore the trend and hence it is necessary to implement a longitudinal study. The aim of this prospective study is to find the trend of glycosylated hemoglobin (HbA1c) over time and the associative factors on it. METHODS: Participants of this longitudinal study were 3440 eligible diabetes patients referred to Isfahan Endocrine and Metabolism Research Center during 2000-2012 who are measured 2-40 times. A linear mixed model was applied to determine the association between HbA1c and variables, including lipids, systolic, diastolic blood pressure and complications such as nephropathy, and retinopathy. Furthermore, the effect of mentioned variables on trend of HbA1c was determined. RESULTS: The fitted model showed total cholesterol, retinopathy, and the method of therapy including oral antidiabetic drugs (OADs) plus insulin and insulin therapy decreased the trend of HbA1c and high-density lipoprotein, weight, hyperlipidemia and the method of therapy including diet, and OADs increased the trend of HbA1c. CONCLUSIONS: The present study shows that regular visits of diabetic patients as well as controlling blood pressure, lipid profile, and weight loss can improve the trend of HbA1c levels during the time.