The Use of Crude Extract of Kohlrabi (Brassica oleracea gongylodes) as a Source of Peroxidase in the Spectrofluorimetric Determination of Thiamine

Amjadi, Mohammad,Manzoori, Jamshid L.,Orooji, Maghsood Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.2

The crude extract of kohlrabi (Brassica oleracea gongylodes) was prepared as a rich source of peroxidase and its enzymatic and specific activities in the presence of cross-linked polyvinylpyrrolidone as a stabilizer were determined. This extract was used to catalyze the oxidation of thiamine in the presence of hydrogen peroxide to thiochrome at pH 8.0. Thiochrome shows strong fluorescence at 436 nm with excitation at 370 nm. Based on the obtained results, a sensitive and simple spectrofluorimetric method was developed for the determination of thiamine. In the optimum conditions, the calibration graph was linear from 2 × 10-7 to 1 × 10-4 mol L-1, with a detection limit of 6.2 × 10-8 mol L-1. The relative standard deviation (RSD) was 1.2% for 5 × 10-6 mol L-1 thiamine. The method was successfully applied to the determination of thiamine in vitamin B1 and vitamin B complex tablets and vitamin B complex syrup.

Highly Stretchable and Sensitive Strain Sensor Based on Silver Nanowire–Elastomer Nanocomposite

Amjadi, Morteza,Pichitpajongkit, Aekachan,Lee, Sangjun,Ryu, Seunghwa,Park, Inkyu American Chemical Society 2014 ACS NANO Vol.8 No.5

<P>The demand for flexible and wearable electronic devices is increasing due to their facile interaction with human body. Flexible, stretchable and wearable sensors can be easily mounted on clothing or directly attached onto the body. Especially, highly stretchable and sensitive strain sensors are needed for the human motion detection. Here, we report highly flexible, stretchable and sensitive strain sensors based on the nanocomposite of silver nanowire (AgNW) network and PDMS elastomer in the form of the sandwich structure (i.e., AgNW thin film embedded between two layers of PDMS). The AgNW network-elastomer nanocomposite based strain sensors show strong piezoresistivity with tunable gauge factors in the ranges of 2 to 14 and a high stretchability up to 70%. We demonstrate the applicability of our high performance strain sensors by fabricating a glove Integrated with five strain sensors for the motion detection of fingers and control of an avatar in the virtual environment.</P>

Transport Costs and "Natural" Integration in Mercosur

Amjadi, Azita,Winters, L. Alan 세종대학교 국제경제연구소 1999 Journal of Economic Integration Vol.14 No.4

The paper explores the argument that trade between the Mercosur countries should be stimulated by preferential policies because of their geographic proximity. That is, that the Mercosur countries are candidates for "natural" intergration. The paper finds that, on average, transportation margins on trade within Mercosur and between Mercosur and Chile are about 6 percentage points lower than on trade with the rest of the world. That is a significant margin, and one that was reflected in the countries' trade patterns even before regional trade agreements reduced the policy-based barriers to mutual trade. But it is probably not large enough, in and of itself (without other benefits), to make the introduction of trade preferences desirable. The paper also explores the argument that absolutely high transportation costs between Mercosur and the rest of the world (that is, not relative to intra-Mercosur costs) justify regional trade preferences. For this to apply the introduction of trade preferences must cause the Mercousur countries to cease importing some goods from the rest of the world completely. While Mercosur-rest-of-the-world transport costs certainly are high, trade patterns suggest that very few goods will cease to be imported from the rest of the world. (JEL-Classifications: F15, R40)

Variable localization of Toll-like receptors in human fallopian tube epithelial cells

Amjadi, Fatemehsadat,Zandieh, Zahra,Salehi, Ensieh,Jafari, Reza,Ghasemi, Nasrin,Aflatoonian, Abbas,Fazeli, Alireza,Aflatoonian, Reza The Korean Society for Reproductive Medicine 2018 Clinical and Experimental Reproductive Medicine Vol.45 No.1

Objective: To determine the localization, expression, and function of Toll-like receptors (TLRs) in fallopian tube epithelial cells. Methods: The localization of TLRs in fallopian tube epithelial cells was investigated by immunostaining. Surprisingly, the intensity of staining was not equal in the secretory and ciliated cells. After primary cell culture of fallopian tube epithelial cells, ring cloning was used to isolate colonies of ciliated epithelial cells, distinct from non-ciliated epithelial cells. The expression of TLRs 1-10 was examined by quantitative real-time polymerase chain reaction, and protein localization was confirmed by immunostaining. The function of the TLRs was determined by interleukin (IL)-6 and IL-8 production in response to TLR2, TLR3, TLR5, TLR7, and TLR9 ligands. Results: Fallopian tube epithelial cells expressed TLRs 1-10 in a cell-type-specific manner. Exposing fallopian tube epithelial cells to TLR2, TLR3, TLR5, TLR7, and TLR9 agonists induced the secretion of proinflammatory cytokines such as IL-6 and IL-8. Conclusion: Our findings suggest that TLR expression in the fallopian tubes is cell-type-specific. According to our results, ciliated cells may play more effective role than non-ciliated cells in the innate immune defense of the fallopian tubes, and in interactions with gametes and embryos.

Antiproliferative Effects of Free and Encapsulated Hypericum Perforatum L. Extract and Its Potential Interaction with Doxorubicin for Esophageal Squamous Cell Carcinoma

Amjadi, Issa,Mohajeri, Mohammad,Borisov, Andrei,Hosseini, Motahare-Sadat KOREAN PHARMACOPUNCTURE INSTITUTE 2019 Journal of pharmacopuncture Vol.22 No.2

Objectives: Esophageal squamous cell carcinoma (ESCC) is considered as a deadly medical condition that affects a growing number of people worldwide. Targeted therapy of ESCC has been suggested recently and required extensive research. With cyclin D1 as a therapeutic target, the present study aimed at evaluating the anticancer effects of doxorubicin (Dox) or Hypericum perforatum L. (HP) extract encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles on the ESCC cell line KYSE30. Methods: Nanoparticles were prepared using double emulsion method. Cytotoxicity assay was carried out to measure the anti-proliferation activity of Dox-loaded (Dox NPs) and HP-loaded nanoparticles (HP NPs) against both cancer and normal cell lines. The mRNA gene expression of cyclin D1 was evaluated to validate the cytotoxicity studies at molecular level. Results: Free drugs and nanoparticles significantly inhibited KYSE30 cells by 55-73% and slightly affected normal cells up to 29%. The IC50 of Dox NPs and HP NPs was ~ 0.04-0.06 mg/mL and ~ 0.6-0.7 mg/mL, respectively. Significant decrease occurred in cyclin D1 expression by Dox NPs and HP NPs (P < 0.05). Exposure of KYSE-30 cells to combined treatments including both Dox and HP extract significantly increased the level of cyclin D1 expression as compared to those with individual treatments (P < 0.05). Conclusion: Dox NPs and HP NPs can successfully and specifically target ESCC cells through downregulation of cyclin D1. The simultaneous use of Dox and HP extract should be avoided for the treatment of ESCC.

Antiproliferative Effects of Free and Encapsulated Hypericum Perforatum L. Extract and Its Potential Interaction with Doxorubicin for Esophageal Squamous Cell Carcinoma

Issa Amjadi,Mohammad Mohajeri,Andrei Borisov,Motahare-Sadat Hosseini 대한약침학회 2019 Journal of pharmacopuncture Vol.22 No.2

Objectives: Esophageal squamous cell carcinoma (ESCC) is considered as a deadly medical condition that affects a growing number of people worldwide. Targeted therapy of ESCC has been suggested recently and required extensive research. With cyclin D1 as a therapeutic target, the present study aimed at evaluating the anticancer effects of doxorubicin (Dox) or Hypericum perforatum L. (HP) extract encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles on the ESCC cell line KYSE30. Methods: Nanoparticles were prepared using double emulsion method. Cytotoxicity assay was carried out to measure the anti-proliferation activity of Dox-loaded (Dox NPs) and HP-loaded nanoparticles (HP NPs) against both cancer and normal cell lines. The mRNA gene expression of cyclin D1 was evaluated to validate the cytotoxicity studies at molecular level. Results: Free drugs and nanoparticles significantly inhibited KYSE30 cells by 55-73% and slightly affected normal cells up to 29%. The IC50 of Dox NPs and HP NPs was ~ 0.04-0.06 mg/mL and ~ 0.6-0.7 mg/mL, respectively. Significant decrease occurred in cyclin D1 expression by Dox NPs and HP NPs (P < 0.05). Exposure of KYSE-30 cells to combined treatments including both Dox and HP extract significantly increased the level of cyclin D1 expression as compared to those with individual treatments (P < 0.05). Conclusion: Dox NPs and HP NPs can successfully and specifically target ESCC cells through downregulation of cyclin D1. The simultaneous use of Dox and HP extract should be avoided for the treatment of ESCC.

The Use of Crude Extract of Kohlrabi (Brassica oleracea gongylodes) as a Source of Peroxidase in the Spectrofluorimetric Determination of Thiamine

Mohammad Amjadi*,Jamshid L. Manzoori,Maghsood Orooji 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.2

The crude extract of kohlrabi (Brassica oleracea gongylodes) was prepared as a rich source of peroxidase and its enzymatic and specific activities in the presence of cross-linked polyvinylpyrrolidone as a stabilizer were determined. This extract was used to catalyze the oxidation of thiamine in the presence of hydrogen peroxide to thiochrome at pH 8.0. Thiochrome shows strong fluorescence at 436 nm with excitation at 370 nm. Based on the obtained results, a sensitive and simple spectrofluorimetric method was developed for the determination of thiamine. In the optimum conditions, the calibration graph was linear from 2´10-7 to 1´10-4 mol L-1, with a detection limit of 6.2´10-8 mol L-1. The relative standard deviation (RSD) was 1.2% for 5´10-6 mol L-1 thiamine. The method was successfully applied to the determination of thiamine in vitamin B1 and vitamin B complex tablets and vitamin B complex syrup.

Transport Costs and "Natural" Integration in Mercosur

( Azita Amjadi ),( L. Alan Winters ) 세종대학교 경제통합연구소 1999 Journal of Economic Integration Vol.14 No.4

The paper explores the argument that trade between the Mercosur countries should be stimulated by preferential policies because of their geographic proximity. That is, that the Mercosur countries are candidates for "natural" integration. The paper finds that, on average, transportation margins on trade within Mercosur and between Mercosur and Chile are about 6 percentage points lower than on trade with the rest of the world. That is a significant margin, and one that was reflected in the countries` trade patterns even before regional trade agreements reduced the policy-based barriers to mutual trade. But it is probably not large enough, in and of itself (without other benefits), to make the introduction of trade preferences desirable. The paper also explores the argument that absolutely high transportation costs between Mercosur and the rest of the world (that is, not relative to intra-Mercosur costs) justify regional trade preferences. For this to apply the introduction of trade preferences must cause the Mercosur countries to cease importing some goods from the rest of the world completely. While Mercosur---rest-of-the-world transport costs certainly are high, trade patterns suggest that very few goods will cease to be imported from the rest of the world. (JEL- Classifications: F15, R40)

The Association Between Dietary Acidity and Clinical Symptoms in Patients With Rheumatoid Arthritis

( Arezoo Amjadi ),( Yahya Pasdar ),( Shahab Rezaeian ),( Mostafa Nachvak ),( Saeid Ghavamzadeh ),( Mohammad Alizadeh ),( Hadi Abdollahzad ),( Jafar Navabi ) 한국임상영양학회 2022 Clinical Nutrition Research Vol.11 No.4

This study aimed to investigate the relationship between dietary acidity load and clinical symptoms in the patients with rheumatoid arthritis (RA). This case-control study examined 55 patients with RA and 215 healthy individuals in a Ravansar non-communicable diseases (RaNCDs) cohort study, Iran. Participants’ food intakes were assessed using a validated food frequency questionnaire. The dietary acidity was calculated using potential renal acid load (PRAL), net endogenous acid production (NEAP), and dietary acid load (DAL) scores. The patients with RA were identified based on the self-reporting, medications history, and the approval of the cohort center physician following patients’ examination. The odds ratio (OR) of joint stiffness in fully adjusted model was greater in the upper median of dietary acidity than in the lower median (PRAL: odds ratio [OR], 1.18; 95% confidence interval [CI], 0.59-2.36), but there was no statistically significant difference. The OR of joint pain in the upper median of dietary acidity was less than in the lower median in fully adjusted model (PRAL: OR, 0.70; 95% CI, 0.46-1.29), but the difference was not statistically significant. After adjusting potential confounders, people in the upper median of dietary acidity had a higher OR of developing RA than those in the lower median (PRAL: OR, 1.39; 95% CI, 0.70-2.76); however, it was not statistically significant. There was not any statistically significant relationship among dietary acidity and the odds of joint pain, joint stiffness, and developing RA.

Wearable, Ultrawide-Range, and Bending-Insensitive Pressure Sensor Based on Carbon Nanotube Network-Coated Porous Elastomer Sponges for Human Interface and Healthcare Devices

Kim, Seunghwan,Amjadi, Morteza,Lee, Tae-Ik,Jeong, Yongrok,Kwon, Donguk,Kim, Min Seong,Kim, Kyuyoung,Kim, Taek-Soo,Oh, Yong Suk,Park, Inkyu American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.26

<P>Flexible and wearable pressure sensors have attracted a tremendous amount of attention due to their wider applications in human interfaces and healthcare monitoring. However, achieving accurate pressure detection and stability against external stimuli (in particular, bending deformation) over a wide range of pressures from tactile to body weight levels is a great challenge. Here, we introduce an ultrawide-range, bending-insensitive, and flexible pressure sensor based on a carbon nanotube (CNT) network-coated thin porous elastomer sponge for use in human interface devices. The integration of the CNT networks into three-dimensional microporous elastomers provides high deformability and a large change in contact between the conductive CNT networks due to the presence of micropores, thereby improving the sensitivity compared with that obtained using CNT-embedded solid elastomers. As electrical pathways are continuously generated up to high compressive strain (∼80%), the pressure sensor shows an ultrawide pressure sensing range (10 Pa to 1.2 MPa) while maintaining favorable sensitivity (0.01-0.02 kPa<SUP>-1</SUP>) and linearity (<I>R</I><SUP>2</SUP> ∼ 0.98). Also, the pressure sensor exhibits excellent electromechanical stability and insensitivity to bending-induced deformations. Finally, we demonstrate that the pressure sensor can be applied in a flexible piano pad as an entertainment human interface device and a flexible foot insole as a wearable healthcare and gait monitoring device.</P> [FIG OMISSION]</BR>