Eye-Related Adverse Events After I-131 Radioiodine Therapy: A Systematic Review of the Current Literature.

OBJECTIVE: Although I-131 is relatively safe, there is limited focus on probable eye-related side effects after radioactive iodine (RAI) therapy. Thus, we aimed to provide evidence for the adverse outcomes of I-131, exclusively in patients with thyroid cancer. METHODS: A systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was designed to examine the ocular complications of RAI therapy. Databases including PubMed, Scopus, and Web of Science were searched until October 2023 with specific thyroid neoplasms, ophthalmology and iodine terms. After thorough screening and review, relevant data were extracted. RESULTS: The database search yielded 3434 articles, which resulted in the final 28 eligible studies. These studies investigated ophthalmic symptoms following RAI therapy, classifying them as obstructive diseases (for example, nasolacrimal duct obstruction; median incidence rate: 6.8%), inflammatory symptoms (median incidence rate: 13%), and cataracts (median incidence rate: 2.5 and 5%). The most common time interval between RAI therapy and the onset of symptoms was within the first 12 months and then declined in the preceding years. A strong positive correlation was observed between higher I-131 doses of more than 100 to 150 mCi (3.7-5.55 GBq) and the risk of symptom development. Ages older than 45 also showed a significant association with nasolacrimal duct obstruction. CONCLUSION: The risk of ophthalmic complications is associated with various factors, including the administration of high I-131 doses, age of more than 45 years, and time to event within the first 12 months. Considering these conditions may help enhance patient care and prevent adverse outcomes that may limit patients' quality of life.

The effect of moderate-intensity aerobic exercise on non-proliferative diabetic retinopathy in type II diabetes mellitus patients: A clinical trial.

INTRODUCTION: Diabetic retinopathy (DR) is one of the most threatening complications of diabetes and a leading cause of visual loss in working-age population. Although exercise is beneficial in diabetes, previous studies have showed contradictory and inconclusive results on how it effects DR. In this study, we aimed to investigate the effect of moderate-intensity aerobic exercise on non-proliferative diabetic retinopathy. MATERIALS & METHODS: In this before-after clinical trial, 40 patients with diabetic retinopathy were enrolled by convenient sampling method in Shahid Labbafinejad Hospital in Tehran during 2021-2022. Before the intervention, central macular thickness (CMT, microns) measured by optical coherence tomography (OCT) and fasting blood sugar (FBS, mg/dl) were obtained. Then, patients took part in a 12-week moderate-intensity aerobic exercise (3 sessions per week, each session 45 min). Data were analyzed using SPSS version 26.0. RESULTS: Out of 40 examined patients, 21 (52.5 %) were male and 19 (47.5 %) were female. The mean age of the patients was 50.8 years. The mean rank of FBS (mg/dl) significantly decreased from 21.12 before the exercise to 8.75 after the exercise (p < 0.001). Also, the mean rank of CMT (microns) showed a significant decrease from 21.11 before the intervention to 16.20 after the exercise (p < 0.001). There was a significant positive correlation between patients' age and FBS (mg/dl) before (rho = 0.457, p = 0.003) and after (rho = 0.365, p = 0.021) the intervention. Also, a significant positive correlation was found between patients' age and CMT (microns) before (rho = 0.525, p = 0.001) and after (rho = 0.461, p = 0.003) moderate exercise. CONCLUSION: Moderate-intensity aerobic exercise leads to lower FBS (mg/dl) and CMT (microns) in patients with diabetic retinopathy, so it may be beneficial for diabetic patients to avoid sedentary lifestyle.

Identifying risk factors for late HIV diagnosis and survival analysis of people living with HIV/AIDS in Iran (1987-2016).

BACKGROUND: Late-diagnosis of HIV is a major challenge for the control and prevention of AIDS in the world. The present study aimed to specify factors associated with the late diagnosis of HIV in Iran from 1987 to 2016. METHODS: In this retrospective cohort study, data for 4402 diagnosed HIV/AIDS patients were extracted from 158 behavioral disease counseling centers of 31 Iranian provinces. We defined late diagnosis as having a CD4 count less than 350 within 3 months after diagnosis. Multiple logistic regression analysis was used to determine the factors influencing late diagnosis. Moreover, we used multivariate Cox regression to assess the association of these factors with the patients' survival. RESULTS: In this study, the prevalence of late diagnosis among the patients was 58.2%. People aged 50 years and over (adjusted OR = 3.55), transmission through blood transfusion (adjusted OR = 2.89), co-infection with tuberculosis (adjusted OR = 2.06), and male gender (adjusted OR = 1.38) were the strongest predictors for late diagnosis of HIV. On the other hand, baseline CD4 (adjusted HR = 2.21), people aged 50 and over (adjusted HR = 1.81), male gender (adjusted HR = 1.76), being a widow (adjusted HR = 1.68), people with unknown transmission way (adjusted HR = 18.24), people who inject drugs (adjusted HR = 1.87), diagnosis at previous years (adjusted HR = 2.45) and co-infection with tuberculosis (adjusted OR = 1.77) significantly associated with the survival of patients. CONCLUSION: The prevalence of late diagnosis is high among Iranian HIV/AIDS. The risk factors of late diagnoses include being males and aged 50 years and over, transmission through blood transfusion, and co-infection with tuberculosis. Therefore, implementation of screening programs for early diagnosis of HIV these high risk groups is recommended to Iranian health providers and policymakers.

Predictors of death in patients with COVID-19: A cross-sectional study in West of Iran.

Background: Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a newly identified coronavirus. Our knowledge about the survival rate and prognostic factors of the disease is not established well. The purpose of this study was to evaluate the predictors of COVID-19 mortality in Hamadan province in western Iran. Methods: In this study, we included all laboratory-confirmed COVID-19 cases with known treatment outcomes in Hamadan province, Iran, between 20, 2020, to May 10, 2020. Demographic, clinical, laboratory data, and treatment outcomes were obtained from computerized medical records and compared between survived cases and patients with death outcomes. Univariable and multivariable logistic regression models were used to determine the predictors of death. Results: From 749 investigated patients, 77 patients (10.28%) died during the treatment. The Mean age of patients was 53.97±19.04 years. Multivariable logistic regression showed that males had 2.07 (95% CI: 1.73, 2.54) fold higher odds of death. Those with 60 years old and more had 6.49 (95% CI: 4.53, 7.93) fold higher odds of death. Patients with an underlying disease had 7.14 (95% CI: 6.94, 7.38) fold higher odds of death, and patients who were hospitalized in the ICU ward had 2.24 (95% CI: 1.75, 2.90) times higher odds of COVID-19 related mortality. Conclusion: The potential predictors of death in COVID-19 cases, including the male gender, older age, and having an underlying disease could help physicians to identify patients with poor prognoses at an early stage and better management of them.

Hypericum perforatum in the treatment of psychiatric and neurodegenerative disorders: Current evidence and potential mechanisms of action.

BACKGROUND: Psychiatric disorders are substantially associated with reduced quality of life and increased mortality. Depression and anxiety are two of the most common psychiatric disorders that often co-occur with each other as well as with other mental health conditions. Because of the limitations of currently available antidepressant therapies, there is a need for agents with improved efficacy and less adverse effects. Hypericum perforatum, widely known as St. John's wort, is a perennial herbaceous plant most well known for its antidepressant properties. METHODS: We reviewed the available in vitro, in vivo, and clinical evidence on the efficacy, safety, and mechanisms of action of St. John's wort and its active constituents in the treatment of psychiatric and neurodegenerative disorders. RESULTS: Several interesting data have been reported about the antidepressant properties of H. perforatum in clinical trials with different designs. In particular, a number of antidepressant-controlled trials demonstrated that H. perforatum and its active ingredients, hypericin and hyperforin, possess antidepressant properties similar to those of tricyclic antidepressants and selective serotonin reuptake inhibitors but with fewer and milder side effects. CONCLUSION: St. John's wort may exert potent antidepressant effects and represents an efficacious and safe treatment. However, the current clinical evidence regarding the efficacy of H. perforatum in other psychiatric and neurodegenerative disorders is not sufficient to draw a robust conclusion.

Combination therapy of mesenchymal stromal cells and sulfasalazine attenuates trinitrobenzene sulfonic acid induced colitis in the rat: The S1P pathway.

Adipose derived mesenchymal stem cells (ASCs) transplantation is a novel immunomodulatory therapeutic tool to ameliorate the symptom of inflammatory bowel disease (IBD). The objective of this study was to investigate the therapeutic effects of combined sufasalazine and ASCs therapy in a rat model of IBD. After induction of colitis in rats, ASCs were cultured and intraperitoneally injected (3 × 106 cells/kg) into the rats on Days 1 and 5 after inducing colitis, in conjunction with daily oral administration of low dose of sulfasalazine (30 mg/kg). The regenerative effects of combination of ASCs and sulfasalazine on ulcerative colitis were assessed by measuring body weight, colonic weight/length ratio, disease activity index, macroscopic scores, histopathological examinations, cytokine, and inflammation markers profiles. In addition, western blot analysis was used to assess the levels of nuclear factor-kappa B (NF-κB) and apoptosis related proteins in colitis tissues. Simultaneous treatment with ASCs and sulfasalazine was associated with significant amelioration of disease activity index, macroscopic and microscopic colitis scores, as well as inhibition of the proinflammatory cytokines in trinitrobenzene sulfonic acid (TNBS)-induced colitis. Moreover, combined ASCs and sulfasalazine therapy effectively inhibited the NF-κB signaling pathway, reduced the expression of Bax and prevented the loss of Bcl-2 proteins in colon tissue of the rats with TNBS-induced colitis. Furthermore, combined treatment with ASCs and sulfasalazine shifted inflammatory M1 to anti-inflammatory M2 macrophages by decreasing the levels of MCP1, CXCL9 and increasing IL-10, Arg-1 levels. In conclusion, combination of ASCs with conventional IBD therapy is potentially a much more powerful strategy to slow the progression of colitis via reducing inflammatory and apoptotic markers than either therapy alone.

A novel copper (II) complex activated both extrinsic and intrinsic apoptotic pathways in liver cancerous cells.

Recent advances have put fundamental focus on the application of copper (II) (Cu [II]) complexes as agents for fighting against cancer. To determine whether [Cu(L)(2imi)] complex as a novel Cu complex can induce apoptosis in HepG2 as cancerous cells and L929 as normal cells via extrinsic or intrinsic apoptotic pathways, both cell lines were treated for 24 and 48 hours at IC50 concentrations of [Cu(L)(2imi)] complex. Then, the expression of some apoptosis-related genes including p53, caspase-8, bcl-2, and bax were assayed by real-time polymerase chain reaction. The [Cu(L)(2imi)] complex seems to inhibit the expression of bcl-2 in complex-treated HepG2 cancerous cells following the 24- and 48-hour treatment. The complex upregulated the p53, bax, and caspase-8 genes, therefore treatment of HepG2 cancerous cells with [Cu(L)(2imi)] complex induces programmed cell death via the upregulation of relative bax/bcl-2 ratio. Finally, this copper complex triggered apoptosis in HepG2 cells via both intrinsic and extrinsic pathway, whereas treatment of normal L929 cells with this complex induce apoptosis only via intrinsic pathway with the upregulation of relative bax/bcl-2 ratio and does not affect the expression level of caspase-8 gene and does not trigger the extrinsic pathway. Finally, these results obtained from present study confirm the role of a novel Cu complex on the induction of apoptosis process in HepG2 and L929 cells by overexpression of bax, inhibition of bcl-2 and increase of the relative bax/bcl-2 ratio. These results support that the [Cu(L)(2imi)] complex is able to induce apoptosis in cancerous cells, therefore, it has a potential for development as a novel anticancer drug.

The effects of transplanted mesenchymal stem cells treated with 17-b estradiol on experimental autoimmune encephalomyelitis.

The present study was conducted aimed at exploring the modulatory effects of 17-b estradiol (17-bED) on mesenchymal stem cells (MSCs) in the EAE (experimental autoimmune encephalomyelitis) animal model of multiple sclerosis (MS). Following the isolation of bone marrow-derived MSCs from the bilateral femurs and tibias of the male Wistar rats, the cells were harvested and cultured in the presence of 100 nM 17-bED for 24 h. EAE was induced in male Wistar rats (8-12 weeks old) using guinea pig spinal cord homogenate, in combination with the complete Freund's adjuvant. The MSC therapy was triggered when all of the animals obtained a disability score. The symptoms were monitored on a daily basis throughout the study until the rats were euthanized. The mRNA expression of cytokines, including IL-17, IFN-γ, TNF-α, IL-10, IL-4, and TGF-ß together with MMP8 and MMP9 as the family members of matrix metalloproteinases (MMPs) in the brain and spinal cord tissues were examined using real-time PCR. The levels of splenocytes-originated IL-10 and IFN-γ cytokines were also measured by ELISA. The MTT-based research findings showed that the infiltration of lymphocytes into the spleen decreased considerably. It was also observed that the mRNA expression of proinflammatory cytokines decreased significantly, while the mRNA levels of anti-inflammatory cytokines increased remarkably. It was also found that the mRNA levels of the examined matrix metalloproteinases (MMP8 and MMP9) were downregulated significantly. The findings of the present study indicated that the administration of 17-bED enhanced the efficacy of MSCs transplantation and modulated immune responses relatively in the EAE model, via the regulation of either pro- or anti-inflammatory cytokines and matrix metalloproteinases.

The cytotoxicity effects of a novel Cu complex on MCF-7 human breast cancerous cells.

A variety of biological activities, such as anti-microbial and anti-tumor properties was reported for 1,10-phenanthroline and its copper complexes. In this study, the anti-proliferative activity of a novel  [Cu(L)(phen)] complex was investigated on MCF-7 breast cancer cells using MTT assay. Since chemotherapy is lake of ability to distinguish between normal cells from cancerous cells, therefore we also investigated the effect of  [Cu(L)(phen)] complex on normal L929 cells. The results showed that following 24 and 48 h exposure of cells with  [Cu(L)(phen)] complex, the IC50 values for MCF-7 were significantly lower than that recorded for L929 and normal cells were less sensitive than cancerous cells to the complex. Additionally, the  [Cu(L)(phen)] complex displayed a time- and concentration-dependent cytotoxic response, with MCF-7 and L929 cells. Also flow cytometry findings suggest that  [Cu(L)(phen)] complex is capable of decreasing cancer cell viability through apoptosis and did not efficiently activate the necrosis process.

Aptamer-based determination of tumor necrosis factor α using a screen-printed graphite electrode modified with gold hexacyanoferrate.

An aptamer based method is presented for the voltammetric determination of human tumor necrosis factor alpha (TNF-α). Layers of gold hexacyanoferrate (AuHCF) and gold nanoparticles (AuNPs) were directly immobilized on a graphite screen-printed electrode (SPE). Through the strong interaction between cyanide ions (CN-) of AuHCF and AuNPs, gold nanoparticles are assembled on the modified SPE, and this allows for the covalent immobilization of thiolated aptamers against TNF-α (TNF-α-Apt). On incubation of the aptasensor with of TNF-α, the Apt/TNF-α complex is formed, and this leads to a hindered electron transfer and to a decrease in the peak current of the redox probe. Under optimum conditions and at a typical working as low as 0.1 V (vs. a silver pseudo electrode), the electrode works in the 10 pg.mL-1 to 40 µg.mL-1 TNF-α concentration range, with a 5.5 pg.mL-1 detection limit. The high sensitivity and wide detection range of this method allowed TNF-α to in human serum be detected even at very low concentrations. Graphical abstract Schematic diagram for fabrication of aptasensor: (a,b) formation of AuHCF film by electrodeposition;

Molecular identification and phylogenetic analysis of Dipetalonema evansi (LEWIS, 1882) in camels (Camelus dromedarius) of Iran.

Despite the economic importance of camels, the parasites that affect them have not received adequate attention so far and molecular studies are scarce compared to other livestock. In this study, we characterized peripheral blood microfilariae in 200 healthy one-humped camels (Camelus dromedarius) from south-east Iran by microscopy and molecular tools to receive a more detailed insight into prevalence and species that affect them. Moreover, adult specimens of the filarial nematode Dipetalonema evansi were collected from the carcass of an infected animal. Microscopic examination was performed on Giemsa-stained blood smears, and blood was also spotted on Whatman FTA(®) cards for DNA analysis. Genomic DNA was extracted, and PCR was carried out for the detection of filaroid helminths, followed by sequence analysis of positive samples. Four samples were positive for microfilariae by microscopy, while 16 animals (8 %) were positive by PCR. Sequence analysis revealed D. evansi in all cases. Phylogenetic analysis of a cytochrome C oxidase subunit I (COI) sequence of filaroid nematodes showed that most species in a single genus cluster in the same clade; however, D. evansi and D. gracile are not monophyletic and branch rather at the base of the tree. Further studies on the life cycle of D. evansi, specifically the identification of intermediate host(s), have become feasible with the provision of the first specific COI sequences in this study.

Clinical Trial of Subcutaneous Steroid Injection in Patients with Migraine Disorder.

BACKGROUND: Neurologic literature on therapeutic effect of subcutaneous corticosteroids in patients with migrainous chronic daily headache is scarce. The aim of this research is to assess the therapeutic effects of this management in such patients. METHODS: Consecutive patients with migrainous chronic daily headache enrolled a prospective before-after therapeutic study during 2010-2013. Methylprednisolone 40 mg was divided into four subcutaneous injection doses. Two injections were administered in the right and left suboccipital area (exactly at retromastoid cervicocranial junction) and the other two injections in the lower medial frontal area (exactly at medial right and left eyebrows). A daily headache diary was filled out by the patients before and one month after the intervention. The severity of pain was classified based on a pain intensity instrument using numeric rating scale from 0-10 point scale. Paired t-test and Chi-square test were used for statistical analysis. RESULTS: 504 patients (378 females, 126 males) with migrainous chronic daily headache were enrolled in the study. Dramatic, significant, moderate, mild, or no improvements respectively constituted 28.6%, 33.3%, 23.8%, and 14.3% of the post treatment courses. Therapeutic effect of intervention on mean pain scores was significant; t=7.38, df=20, P=0.000. Two cases developed subcutaneous fat atrophy in frontal injection site and three cases experienced syncope during injection. CONCLUSION: Subcutaneous corticosteroids could be used as an adjunct therapy in patients with migrainous chronic daily headache.

Altered expression of apoptotic genes in response to OCT4B1 suppression in human tumor cell lines.

OCT4B1 is a newly discovered spliced variant of OCT4 which is primarily expressed in pluripotent and tumor cells. Based on our previous studies, OCT4B1 is significantly overexpressed in tumors, where it endows an anti-apoptotic property to tumor cells. However, the mechanism by which OCT4B1 regulates the apoptotic pathway is not yet elucidated. Here, we investigated the effects of OCT4B1 suppression on the expression alteration of 84 genes involved in apoptotic pathway. The AGS (gastric adenocarcinoma), 5637 (bladder tumor), and U-87MG (brain tumor) cell lines were transfected with OCT4B1 or irrelevant siRNAs. The expression level of apoptotic genes was then quantified using a human apoptosis panel-PCR kit. Our data revealed an almost similar pattern of alteration in the expression profile of apoptotic genes in all three studied cell lines, following OCT4B1 suppression. In general, the expression of more than 54 apoptotic genes (64 % of arrayed genes) showed significant changes. Among these, some up-regulated (CIDEA, CIDEB, TNFRSF1A, TNFRSF21, TNFRSF11B, TNFRSF10B, and CASP7) and down-regulated (BCL2, BCL2L11, TP73, TP53, BAD, TRAF3, TRAF2, BRAF, BNIP3L, BFAR, and BAX) genes had on average more than tenfold gene expression alteration in all three examined cell lines. With some minor exceptions, suppression of OCT4B1 caused upregulation of pro-apoptotic and down-regulation of anti-apoptotic genes in transfected tumor cells. Uncovering OCT4B1 down-stream targets could further elucidate its part in tumorigenesis, and could lead to finding a new approach to combat cancer, based on targeting OCT4B1.

Preconcentration of organochlorine pesticides in aqueous samples by dispersive liquid-liquid microextraction based on solidification of floating organic drop after SPE with multiwalled carbon nanotubes.

SPE joined with dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) as a novel technique combined with GC with electron-capture detection has been developed as a preconcentration technique for the determination of organochlorine pesticides (OCPs) in water samples. Aqueous samples were loaded onto multiwalled carbon nanotubes as sorbent. After the elution of the desired compounds from the sorbent by using acetone, the DLLME-SFO technique was performed on the obtained solution. Variables affecting the performance of both steps such as sample solution flow rate, breakthrough volume, type and volume of the elution, type and volume of extraction solvent and salt addition were studied and optimized. The new method provided an ultra enrichment factor (8280-28221) for nine OCPs. The calibration curves were linear in the range of 0.5-1000 ng/L, and the LODs ranged from 0.1-0.39 ng/L. The RSD, for 0.01 µg/L of OCPs, was in the range of 1.39-13.50% (n = 7). The recoveries of method in water samples were 70-113%.

Distribution and prevalence of refractive error in Iranian adult population results of the PERSIAN eye cohort study PECS.

The Persian Eye Cohort Study, a population-based cross-sectional study from 2015 to 2020, examined refractive error prevalence among 48,618 Iranian adults aged 31 to 70. The study encompassed six centers in Iran, employing random cluster sampling for demographic, medical, and socioeconomic data collection through interviews. Ophthalmic exams included visual acuity, automated and manual objective refraction, subjective refraction, slit lamp, and fundus examinations. Using the spherical equivalent definition, the sample population was categorized into groups. Results indicated a mean age of 49.52 ± 9.31 and a mean refractive error of 0.26 diopters (D) ± 1.6 SD (95% CI - 0.27 to -0.24), ranging from -26.1 to + 18.5 SD. Prevalence of myopia (< -0.5D) and hyperopia (> + 0.5D) was 22.6% (95% CI 22.2-23%) and 12.5% (95% CI 12.1-12.8%), respectively. Regarding different age groups, the prevalence of hyperopia and astigmatism exhibited a steady and significant rise with increasing age (p-value < 0.001 for both). The prevalence of Myopia, however, showed a distinctive pattern, initially increasing in adults under 45, declining in those aged 55-64, and rising again among individuals aged 60 and older. Female gender, older age, urban residency, higher education, higher income, and Fars ethnicity were significantly related to a higher prevalence of myopia (p-value < 0.001 for all). Female gender (p-value < 0.001), aging (p-value < 0.001), urban residency (p-value = 0.029), and lower-income (p-value = 0.005) were significantly related to higher prevalence of hyperopia. Astigmatism (> 1D) was prevalent in 25.5% of participants (95% CI 25.1-25.9%) and correlated with male gender, aging, urban residency, illiteracy, and higher income (p-value < 0.001, < 0.001, < 0.001, < 0.001, 0.014, respectively). The study's comparison with regional and international surveys highlighted the increase in myopia among those over 65 due to higher nuclear cataract rates in older adults. Myopia positively related to education, income, and urban residency, while hyperopia did not exhibit such associations.

The regulatory impacts of Morus Alba leaf extract on some enzymes involved in glucose metabolism pathways in diabetic rat liver.

BACKGROUND: Many traditional therapies have been proposed as alternative regimens for treatment of diabetes mellitus. The Morus Alba (MA) leaf is a natural therapeutic compound which is shown to have antidiabetic properties. The aim of the present study was to determine whether MA leaf extract is capable of regulating liver enzymes that are involved in glucose metabolism pathways in normal and Streptozotocin (STZ)-induced diabetic rats. METHODS: Forty healthy adult male Wistar rats (eight weeks old) weighing about 250 +/- 10 g were taken for this experiment. The rats were divided into 4 groups with 10 rats in each group and treated through a gavage tube for a period of two months as follows: group I: non diabetic control rats with distilled water; group II: non diabetic rats with 1.0 g/kg per day; group III: diabetic control rats with distilled water and group IV: diabetic rats with MA 1.0 g/kg per day. At the end of the 8th week, serum glucose, insulin and hepatic glucokinase activity were measured using standard methods and compared between diabetic and healthy rats. We also assessed the expression of phosphofructokinase-1 enzyme at the level of mRNA, using a Real Time-PCR method. RESULTS: Findings of the present study demonstrated that MA leaf extract can significantly increase liver glucokinase activity and serum insulin levels in diabetic rats (p < 0.05). It also significantly attenuated the serum glucose level in rats compared to the control groups (p < 0.05). Also, the body weight of diabetic rats was significantly (p < 0.05) decreased as compared to their initial weight. However, the body weights of diabetic rats treated with MA increased in the same way as normal control rats. CONCLUSIONS: The present findings suggest that the antihyperglycemic action of MA is mediated by increasing liver glucokinase activity and serum insulin level. These results are additional, definite evidence supporting MA as traditional medicine for diabetic patients.

Preparation and application of carbon nanotubes/poly(o-toluidine) composite fibers for the headspace solid-phase microextraction of benzene, toluene, ethylbenzene, and xylenes.

A novel nanocomposite coating of poly(o-toluidine) and oxidized multiwalled CNTs (MWCNTs, where CNTs is carbon nanotubes) was electrochemically prepared on a stainless-steel wire. The applicability of the fiber was assessed for the headspace solid-phase microextraction of benzene, toluene, ethylbenzene, and xylenes in aqueous samples followed by GC with flame ionization detection. In order to obtain an adherent and stable composite coating, several experimental parameters related to the coating process, such as polymerization potential and time, and the concentration of o-toluidine and oxidized MWCNTs were optimized. The combination of MWCNTs and polymer in a nanocomposite form presents desirable opportunities to produce materials for new applications. The effects of various parameters on the efficiency of the headspace solid-phase microextraction process, such as desorption temperature and time, extraction temperature and time, and ionic strength were also investigated. At the optimum conditions, LODs were 0.03-0.06 µg/L. The method showed linearity in the range of 0.5-300 µg/L with coefficients of determination >0.99. The intraday and interday RSDs obtained at a 5 µg/L concentration level (n = 5) using a single fiber were 1.2-5.2 and 3.2-7.5%, respectively. The fiber-to-fiber RSD (%; n = 3) at 5 µg/L was 6.1-9.2%.

A simple and rapid dispersive liquid-liquid microextraction based on solidification of floating organic drop method combined with flame atomic absorption spectrometry for preconcentration and determination of copper.

A simple and rapid dispersive liquid-liquid microextraction based on solidification of floating organic drop method prior to flame atomic absorption spectrometry was developed for preconcentration and determination of copper. In this technique, simultaneous complex formation and extraction was performed with rapid injection of a mixture containing ethanol, 1-undecanol, and 1-(2-pyridylazo)-2-naphthol into a water sample spiked with Cu(II). After centrifugation, the test tube was cooled in an ice bath, and solidified extract transferred into a conical vial. Finally, it was dissolved into ethanol and copper concentration was determined. Some effective parameters of extraction and complex formation, such as extraction and disperser solvent type and volume, pH, concentration of the chelating agent, salt effect, and extraction time, were optimized. Under the optimum conditions, the calibration graph was linear in the range of 0.50 ng/mL to 0.30 microg/mL, with an LOD of 0.16 ng/mL. The RSD for 10 replicate measurements of 50.0 ng/mL of copper was +/- 1.4%. Two certified reference materials were analyzed, and the determined values were in good agreement with the certified values.

An experimental study for enhancing the catalytic effects of various copper forms on the oxidation of ferrous iron.

In this research the catalytic effect of copper compounds (ionic, oxide and oxide nanopowder) on the oxidation of ferrous iron by aeration was studied experimentally. When copper exists in solution, the oxidation rate of iron(II) will increase. The experimental results showed that the oxidation rate increases with an increasing copper concentration. From the experimental data it can be determined that the copper oxide nanopowder is the most effective for the oxidation reaction among the used copper forms. Aeration is the most economical oxidation method when water exhibits a high ferrous iron concentration.

Adaptive super-twisting control for leader-following consensus of second-order multi-agent systems based on time-varying gains.

In this paper, robust distributed consensus control is designed based on adaptive time-varying gains for a class of nonlinear multi-agent systems (MAS) in the presence of uncertain parameters and external disturbances with unknown upper bounds. Due to various conditions and constraints, different dynamical models for the agents can be considered in practice. On the basis of a continuous homogeneous consensus method which has been proposed for the nominal nonlinear MAS, the discontinuous and continuous adaptive integral sliding mode control strategies are particularly designed and extended to accomplish exact and precise consensus for non-identical MASs influenced by imposed perturbations. However, it is noted that in practical problems, the exact upper bound of perturbations is unknown. Then, the proposed controllers have been improved in an adaptive scheme to overcome this drawback. In addition to the adaptive estimation strategy and time-varying gains, which address considered uncertain parameters in the dynamics of the following agents, the designed distributed super-twisting sliding mode strategy for nonlinear agents adjusts the gain of the control inputs and guarantees that the proposed protocol performs properly without any setbacks of the chattering phenomenon. The illustrative simulations depict the robustness, accuracy, and effectiveness of the designed methods.