32 results on '"Samai, S."'
Search Results
2. Joint modeling of potential-field data and geodynamic interpretation for northeast Algeria
- Author
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Benhenni, L., Quesnel, Y., Berguig, M.C., Samai, S., and Hamoudi, M.
- Published
- 2019
- Full Text
- View/download PDF
3. Identification of the distribution and characteristics of local sago from Kendari, Southeast Sulawesi.
- Author
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Yusuf, D N, Leomo, S, Rakian, T C, Sutariati, G A K, Rahni, N M, and Samai, S
- Published
- 2023
- Full Text
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4. Atmospheric Chlorine Reaction with N-Methyl-2-Pyrrolidinone (NMP)
- Author
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Samai, S., primary and Ferhati, A., additional
- Published
- 2021
- Full Text
- View/download PDF
5. An association between TRP64ARG polymorphism of the B3 adrenoreceptor gene and some metabolic disturbances
- Author
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Abilova Samai S, Zalesskaya Yulia V, Moldokeeva Cholpon B, Lunegova Olga S, Kerimkulova Alina S, Mirrakhimov Aibek E, Sovhozova Nurmira A, Aldashev Almaz A, and Mirrakhimov Erkin M
- Subjects
metabolic syndrome ,B adrenoreceptors ,Trp64Arg polymorphism ,abdominal obesity ,dyslipidemia ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Abstract Backgrounds B3 adrenoreceptors (ADRB3) are abundant in adipose tissue and play the role in its metabolism and lipolysis. Some variants of the ADRB3 gene may predispose subjects for the development obesity and metabolic abnormalities in the setting of modern sedentary lifestyle. ADRB3 gene polymorphism association with metabolic disturbances has never been studied before in the ethnic Kyrgyz population. Aim To study an association between Trp64Arg polymorphism of the ADRB3 and metabolic syndrome (MS) components in an ethnic Kyrgyz group. Materials and methods 213 Ethnic Kyrgyz volunteers over the age of 30 were enrolled in the study. The assessment plan for each individual comprised of general physical and anthropometric exams as well as laboratory tests (glucose, lipid panel, insulin) and genotyping by Trp64Arg polymorphism of the ADRB3. MS diagnosis was consistent with modified ATP III criteria (2005). Logistic regression analysis was performed to test the potential independent association between Arg64 allele with obesity, abdominal obesity (AO) and arterial hypertension (AH). Results Trp64Arg polymorphism of the ADRB3 was assessed in 213 individuals (145 men, 68 women) aged 30-73 (mean age 50.7 ± 7.6). Arg64 allele frequency was 0.239; ADRB3 genotype distribution among participants was: Trp64 homozygotes 54.5%, Trp64Arg 43.2% and Arg64 homozygotes 2.3%. There was an association between Trp64Arg и Arg64Arg genotypes and higher BMI, WC and obesity frequency (p < 0.00009), AO (p < 0.01), type 2 diabetes mellitus (DM) (p < 0.005) and lower high density cholesterol (HDL-C) level (p < 0.03). The logistic regression analysis showed the correlation of the Arg64 allele with obesity (OR 3.159; 95% CI 1.789-5.577) and AO (OR 1.973; 95% CI 1.118-3.481). The association between Arg64 allele and AH lost its significance after adjustment for obesity. Conclusion Arg64 allele of the ADRB3 gene in the studied group has an association with MS components such as obesity, AO and decreased HDL-C level.
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- 2011
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6. Atmospheric Reaction of Cl with 4-Hydroxy-2-pentanone (4H2P): A Theoretical Study
- Author
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Rouichi, S., primary, Samai, S., additional, Ferhati, A., additional, and Chakir, A., additional
- Published
- 2018
- Full Text
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7. Gravity interpretation using multi-scale analysis in the Algiers area (Algeria)
- Author
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Benaissa*, Z., primary, Benhenni, L., additional, Samai, S., additional, Djeddi, M., additional, Boukerbout, H., additional, and Boudella, A., additional
- Published
- 2015
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- View/download PDF
8. An association between TRP64ARG polymorphism of the B3 adrenoreceptor gene and some metabolic disturbances
- Author
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Mirrakhimov, Aibek E, primary, Kerimkulova, Alina S, additional, Lunegova, Olga S, additional, Moldokeeva, Cholpon B, additional, Zalesskaya, Yulia V, additional, Abilova, Samai S, additional, Sovhozova, Nurmira A, additional, Aldashev, Almaz A, additional, and Mirrakhimov, Erkin M, additional
- Published
- 2011
- Full Text
- View/download PDF
9. An association between TRP64ARG polymorphism of the B3 adrenoreceptor gene and some metabolic disturbances
- Author
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Aibek E. Mirrakhimov, Erkin M. Mirrakhimov, Nurmira Sovhozova, Samai S Abilova, Yulia V Zalesskaya, Almaz Aldashev, Cholpon B Moldokeeva, Alina Kerimkulova, and Lunegova Os
- Subjects
Adult ,Male ,lcsh:Diseases of the circulatory (Cardiovascular) system ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Population ,Arginine ,abdominal obesity ,Diabetes mellitus ,Internal medicine ,Genotype ,medicine ,Humans ,Obesity ,Allele ,Kyrgyzstan ,education ,Allele frequency ,Alleles ,Genetic Association Studies ,Abdominal obesity ,Aged ,Original Investigation ,Metabolic Syndrome ,education.field_of_study ,Polymorphism, Genetic ,B adrenoreceptors ,business.industry ,dyslipidemia ,Tryptophan ,Middle Aged ,medicine.disease ,Endocrinology ,Diabetes Mellitus, Type 2 ,lcsh:RC666-701 ,Receptors, Adrenergic, beta-3 ,Female ,Trp64Arg polymorphism ,medicine.symptom ,Metabolic syndrome ,Cardiology and Cardiovascular Medicine ,business - Abstract
Backgrounds B3 adrenoreceptors (ADRB3) are abundant in adipose tissue and play the role in its metabolism and lipolysis. Some variants of the ADRB3 gene may predispose subjects for the development obesity and metabolic abnormalities in the setting of modern sedentary lifestyle. ADRB3 gene polymorphism association with metabolic disturbances has never been studied before in the ethnic Kyrgyz population. Aim To study an association between Trp64Arg polymorphism of the ADRB3 and metabolic syndrome (MS) components in an ethnic Kyrgyz group. Materials and methods 213 Ethnic Kyrgyz volunteers over the age of 30 were enrolled in the study. The assessment plan for each individual comprised of general physical and anthropometric exams as well as laboratory tests (glucose, lipid panel, insulin) and genotyping by Trp64Arg polymorphism of the ADRB3. MS diagnosis was consistent with modified ATP III criteria (2005). Logistic regression analysis was performed to test the potential independent association between Arg64 allele with obesity, abdominal obesity (AO) and arterial hypertension (AH). Results Trp64Arg polymorphism of the ADRB3 was assessed in 213 individuals (145 men, 68 women) aged 30-73 (mean age 50.7 ± 7.6). Arg64 allele frequency was 0.239; ADRB3 genotype distribution among participants was: Trp64 homozygotes 54.5%, Trp64Arg 43.2% and Arg64 homozygotes 2.3%. There was an association between Trp64Arg и Arg64Arg genotypes and higher BMI, WC and obesity frequency (p < 0.00009), AO (p < 0.01), type 2 diabetes mellitus (DM) (p < 0.005) and lower high density cholesterol (HDL-C) level (p < 0.03). The logistic regression analysis showed the correlation of the Arg64 allele with obesity (OR 3.159; 95% CI 1.789-5.577) and AO (OR 1.973; 95% CI 1.118-3.481). The association between Arg64 allele and AH lost its significance after adjustment for obesity. Conclusion Arg64 allele of the ADRB3 gene in the studied group has an association with MS components such as obesity, AO and decreased HDL-C level.
- Published
- 2011
10. Geographic and Ethnic Distribution of β-Thalassemia Mutations in Uttar Pradesh, India
- Author
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Agarwal, S., primary, Pradhan, M., additional, Gupta, U. R., additional, Samai, S., additional, and Agarwal, S. S., additional
- Published
- 2000
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11. Microwave assisted synthesis, chemiluminescent and theoretical studies of bromoalkyl esters of acridine-9-carboxylic acid
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Samai, S., Nandi, G. C., Singh, P., Ashutosh Gupta, and Singh, M. S.
12. Factors Associated with Suspected Developmental Delay in Thai Children Born with Low Birth Weight or Asphyxia.
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Tangviriyapaiboon D, Thaineua V, Sirithongthaworn S, Kanshana S, Damrongtamwattana S, Prasitwattanaseree S, Srikummoon P, Thongsak N, Thumronglaohapun S, and Traisathit P
- Subjects
- Infant, Newborn, Female, Child, Humans, Infant, Birth Weight, Thailand epidemiology, Infant, Low Birth Weight, Risk Factors, Asphyxia, Developmental Disabilities diagnosis, Developmental Disabilities epidemiology, Developmental Disabilities etiology
- Abstract
Objectives: The aim of the study was to identify factors associated with a risk of suspected developmental delay (SDD) in high-risk children in Thailand., Methods: We used data on children enrolled for developmental delay (DD) screening across Thailand collected by the Rajanagarindra Institute of Child Development, Department of Mental Health, Ministry of Public Health, Thailand. Children who were under 5 years of age with a birth weight of fewer than 2500 g and/or birth asphyxia in Thailand with high risk of DD were assessed using the Developmental Assessment for Intervention Manual (DAIM) between August 2013 and November 2019 (N = 14,314)., Results: The high-risk children who had a gestational age at birth of < 37 weeks (adjusted odds ratio = 1.54; 95% confidence interval = 1.39-1.70) and/or had a birth weight < 2500 g (1.22; 1.02-1.45), or had mothers who were not government officers (1.46; 1.11-1.93), had a low education level (1.36; 1.19-1.55), had a poor nutritional status (1.34; 1.09-1.65), and/or who were living in a high-altitude area (1.59; 1.32-1.91) were at a higher risk of SDD., Conclusions for Practice: Children with a low birth weight and/or asphyxia during birth had a high risk of DD. SDD monitoring of children by community health workers and/or by developing outreach strategies, especially in underserved regions, should be considered. In addition, developing policies and guidelines, and intervention for high-risk children ought to be conducted to reduce the subsequent problems caused by the late detection of DD., (© 2023. The Author(s).)
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- 2024
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13. A 9-year retrospective cohort study of the monitoring and screening of childhood developmental delay in Thailand.
- Author
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Thaineua V, Sirithongthaworn S, Kanshana S, Isaranurak S, Karnkawinpong O, Benjaponpitak A, Wattanayingcharoen S, Piensrivachara E, Srikummoon P, Thumronglaohapun S, Nakharutai N, Traisathit P, and Tangviriyapaiboon D
- Subjects
- Child, Humans, Child, Preschool, Infant, Newborn, Infant, Thailand epidemiology, Retrospective Studies, Parents, Developmental Disabilities diagnosis, Developmental Disabilities epidemiology, Mass Screening
- Abstract
Background: Developmental delay in early childhood can have negative long-term cognitive and psychiatric sequelae, along with poor academic achievement, so early screening and surveillance are paramount. The aim of this study is to evaluate the impact of screening and surveillance on child developmental delay using the Developmental Surveillance and Promotion Manual (DSPM) and the Thai Early Developmental Assessment for Intervention (TEDA4I) for Thai children aged 0-5 years old., Methods: Data were obtained from the routine developmental screening for specific disorders at ages 9, 18, 30, 42 and 60 months conducted using DSPM and TEDA4I from 2013 to 2021. Descriptive statistics were used to analyse the data, and the results are visualised graphically herein., Results: Only 56% of the children were screened for child developmental delay using DSPM. The proportion of children screened increased from <1% in 2013 to 90% in 2021. Suspected developmental delay prevalence increased significantly from 3.91% in 2013-2015 to 10.00% in 2016-2018 and 26.48% in 2019-2021. Moreover, of the children with suspected developmental delay who received developmental stimulation within a month, only 87.9% returned for follow-up visits when they were evaluated again using TEDA4I to ascertain any abnormalities and specific areas of deficit. The overall proportion of children diagnosed with developmental delay was 1.29%. During the pandemic, the proportion of screening tests for child developmental delay at routine vaccination visits and follow-ups decreased but was still at least 80% in each region., Conclusions: Since 1%-3% of children have suspected developmental delay, early detection is key to treating it as soon as possible. We anticipate that our findings will raise awareness in parents and caregivers about childhood developmental delay and lead to the implementation of early intervention and follow-up at the rural level in Thailand., (© 2024 The Authors. Child: Care, Health and Development published by John Wiley & Sons Ltd.)
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- 2024
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14. The Optimal Cut-Off Point for Thai Diagnostic Autism Scale and Probability Prediction of Autism Spectrum Disorder Diagnosis in Suspected Children.
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Tangviriyapaiboon D, Kawilapat S, Sirithongthaworn S, Apikomonkon H, Suyakong C, Srikummoon P, Thumronglaohapun S, and Traisathit P
- Abstract
The Thai Diagnostic Autism Scale (TDAS) was developed to diagnose autism spectrum disorder (ASD) under the context and characteristics of the Thai population. Although the tool has an excellent agreement, the interpretation of diagnostic results needs to rely on the optimal cut-off point to maximize efficiency and clarity. This study aims to find an optimal cut-off point for TDAS in the diagnosis of ASD and to compare its agreement with the DSM-5 ASD criteria. This study was conducted on 156 children aged 12-48 months old who were suspected of having ASD and had enrolled from hospitals in the four regions of Thailand in 2017-2018. The optimal cut-off point for TDAS was considered by using receiver operating characteristic (ROC) curves according to the DSM-5 ASD criteria. The areas under the curve (AUCs) for TDAS and ADOS-2 were also compared. Multivariable logistic regression was performed to create a predictive model for the probability of ASD. The AUC of TDAS was significantly higher than that of ADOS-2 (0.8748 vs. 0.7993; p = 0.033). The optimal cut-off point for TDAS was ≥20 points (accuracy = 82.05%, sensitivity = 82.86%, and specificity = 80.93%). Our findings show that TDAS with a cut-off point can yield higher diagnostic accuracy than ADOS-2 and TDAS domain. Diagnosis by using this cut-off point could be useful in practical assessments.
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- 2022
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15. Development and psychometric evaluation of a Thai Diagnostic Autism Scale for the early diagnosis of Autism Spectrum Disorder.
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Tangviriyapaiboon D, Sirithongthaworn S, Apikomonkon H, Suyakong C, Srikummoon P, Kawilapat S, and Traisathit P
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- Child, Child, Preschool, Early Diagnosis, Humans, Infant, Psychometrics, Reproducibility of Results, Thailand, Autism Spectrum Disorder diagnosis, Autistic Disorder diagnosis
- Abstract
The Thai Diagnostic Autism Scale (TDAS) was developed for use as a diagnostic tool for the early diagnosis of Autism Spectrum Disorder (ASD) in Thai children aged 12-48 months old. TDAS consists of 23 items (13 and 17 items in the observational and interview sections, respectively) classified into seven domains (A1-A3 and B1-B4) according to the criteria in the Diagnostic and Statistical Manual of Mental Disorder, fifth edition (DSM-5). Children with a single score in the A1-A3 domains and at least two of the B1-B4 domains were classified with ASD. The item-objective congruence (IOC) index, confirmatory factor analysis, and Kappa coefficient were used to evaluate the content, constructs, and inter-rater validity levels between the evaluators and concurrent validity between TDAS and physicians' diagnoses, respectively. TDAS showed good overall content validity (IOC range 0.71-1.00), suitable construct validity (root-mean-squared errors of approximation of 0.076 and 0.067, comparative fit indexes of 0.902 and 0.858, and Tucker-Lewis indexes of 0.882 and 0.837 for the observation and interview sections, respectively), and excellent diagnostic agreement between TDAS and the evaluators (Kappa = 1.000) as well as between TDAS and the physicians' diagnoses (Kappa = 0.871). The sensitivity and specificity of TDAS were 100% and 82.4%, respectively. In conclusion, TDAS yielded a high level of content validity, concurrent validity, and inter-rater reliability for the early diagnosis of ASD in Thai children. A large-scale study using TDAS is needed to determine an appropriate cut-off point as well as its efficacy. LAY SUMMARY: The Thai Diagnostic Autism Scale was developed for use as a diagnostic tool for the early diagnosis of Autism Spectrum Disorder (ASD) among Thai children. It contains 23 items in seven domains for the screening via observations and interviews. The psychometric properties of this diagnostic tool provide its reliability and suitability for the early diagnosis of ASD. A large-scale study using it is needed to determine an appropriate cut-off point as well as its efficacy., (© 2021 The Authors. Autism Research published by International Society for Autism Research and Wiley Periodicals LLC.)
- Published
- 2022
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16. Cycling of people with a lower limb amputation in Thailand.
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Poonsiri J, Dekker R, Dijkstra PU, Nutchamlong Y, Dismanopnarong C, Puttipaisan C, Suakonburi S, Pimchan P, Hijmans JM, and Geertzen JHB
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- Adult, Aged, Female, Health Behavior, Humans, Life Style, Male, Middle Aged, Surveys and Questionnaires, Thailand, Amputation, Surgical, Amputees, Artificial Limbs, Bicycling physiology
- Abstract
Aim: To investigate cycling participation and barriers, and facilitators in adults with a lower limb amputation in Thailand., Method: Questionnaires were given to 424 adults with uni/bilateral lower limb amputation from midfoot to hip disarticulation level at five public hospitals in Bangkok and prosthetic mobile units in Thailand. Participant characteristics were summarized using descriptive statistics. Variables associated with cycling (p<0.1) were entered in a logistic regression model., Results: Participants who cycled (46.7%, N = 197), mostly used their walking prostheses (91.9%, n = 188). Of cyclists, 92.4% had cycled before the amputation. Cyclists started cycling after the amputation by themselves (86.7%) mostly in order to increase/maintain health (67.0%). Most cyclists cycled on quiet roads. The most frequent destination was shops/market (64.1%). More facilitators were reported than barriers. Most reported barriers were related to health problems and negative attitudes toward cycling. Most reported facilitators were related to perceived health benefits and positive attitude toward cycling. The likelihood of cycling after the amputation increased in people who cycled before the amputation, were amputated lower than the knee, used a prosthetic foot with axis/axes, were amputated due to trauma, had income higher than 415 euro/month, and who reported a higher numbers of facilitators., Conclusion: After a lower limb amputation, nearly half of people cycled. People with a below knee amputation due to trauma with prior cycling experience and higher income tended to cycle after the amputation. People who perceived more facilitators were more likely to cycle. Although cyclists could use a walking prosthesis to cycle, a prosthetic foot with a greater range of motion than the SACH increased the cycling likelihood., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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17. Optical Properties of Reconfigurable Polymer/Silver Nanoprism Hybrids: Tunable Color and Infrared Scattering Contrast.
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Samai S, Qian Z, Ling J, Guye KN, and Ginger DS
- Abstract
We synthesize and characterize stimulus-responsive nanocomposites consisting of poly( N-isopropylacrylamide) (PNIPAM) with controlled loadings of anisotropic plate-like silver nanoprisms. These composites show strong, reversible switching of their optical extinction and scattering properties in response to temperature cycling. We use UV-vis-NIR spectroscopy and dynamic light scattering to characterize the hybrids and show that the loading density of the silver nanoprisms in the polymer and the size of the nanoprisms are both factors that can be used to tailor the optical response of the composites, extending the range of colors beyond that previously reported with PNIPAM/plasmonic nanoparticle composites. These PNIPAM/silver nanoprism hybrids exhibit thermochromic shifts that are 5-10 times larger than those typically reported for similar structures of PNIPAM composites with silver nanoparticles of a comparable range of loading density. In addition, we show that these composites can exhibit very large ratiometric changes in scattering in the NIR, which could open applications for related materials in thermal management and NIR labeling and taggants.
- Published
- 2018
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18. Alcohol use disorder and tuberculosis treatment: A longitudinal mixed method study in Thailand.
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Laprawat S, Peltzer K, Pansila W, and Tansakul C
- Abstract
Objective: The relationship between tuberculosis (TB) treatment and alcohol use disorders over time is under-researched. The aim of this investigation was to study alcohol use and TB medication adherence and its predictors among TB patients over a period of 6 months., Methods: A longitudinal investigation was carried out with new TB and TB retreatment patients systematically selected from two hospitals and had screened positive for hazardous or harmful alcohol use in Sisaket Province in Thailand. Alcohol use disorders were measured with Alcohol Use Disorder Identification Test (AUDIT)-C at baseline, 3 months and 6 months., Results: Of the 295 TB patients who were screened with AUDIT-C, 72 (24.4%) tested positive for hazardous or harmful alcohol use. At 6 months, 72 TB patients had completed the follow-up. At the 6-month follow-up, hazardous or harmful drinking was reduced by 84.7%. Multivariate logistic regression analysis using generalised estimation equation modelling found that alcohol use significantly reduced over time, whereas there was no change in current tobacco use., Conclusion: The prevalence of alcohol use disorders significantly reduced over a period of 6 months., Competing Interests: The authors declare that they have no financial or personal relationships which may have inappropriately influenced them in writing this article.
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- 2017
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19. Switching Selectivity of α-Enolic Dithioesters: One Pot Access to Functionalized 1,2- and 1,3-Dithioles.
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Koley S, Chanda T, Samai S, and Singh MS
- Abstract
An operationally simple cascade protocol has been developed for the construction of 1,2- and 1,3-dithiole derivatives from α-enolic dithioesters. 1,2-Dithioles are achieved by the reaction of dithioesters with elemental sulfur in the presence of InCl
3 under solvent-free conditions. 1,3-Dithioles have been constructed via DABCO mediated self-coupling of dithioesters in open air enabling the formation of two new C-S bonds and one ring in a single operation in contiguous fashion. The reactions proceeded smoothly affording the desired sulfur-rich heterocycles in good to excellent yields, exhibiting gram-scale ability and broad functional group tolerance utilizing easy to handle cheap and easily available reagents. The probable mechanisms for the formation of 1,2- and 1,3-dithioles from α-enolic dithioesters have been suggested.- Published
- 2016
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20. Dynamic Melting Properties of Photoswitch-Modified DNA: Shearing versus Unzipping.
- Author
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Zhang J, Yan Y, Samai S, and Ginger DS
- Abstract
We use dynamic force spectroscopy to study the melting properties of azobenzene-modified double-stranded DNA (azo-dsDNA) in both the shearing and unzipping geometries. By fitting the rupture force vs loading rate data with a Friddle-Noy-De Yoreo model, we extract the location of the barrier (x
t ), the equilibrium force for the bond/transducer system (Feq ), and the dissociation rate of dsDNA (koff 0 ). We find that the koff 0 of azo-dsDNA increases after UV illumination (365 nm) in both the shearing and unzipping geometries. Notably, we find that koff 0 of azo-dsDNA in the unzipping geometry is 5-7 orders of magnitude larger than that in the shearing geometry, a result that helps explain the dependence of koff 0 on the azobenzene photoswitch position during shearing experiments. We also extract the difference of free energy (ΔGbu ) between binding and unbinding states of azo-dsDNA with Feq and the system spring constant (kc ). Our results provide important insights into the dynamic melting properties of azo-dsDNA and a new route for designing applications for reconfigurable sensors, stimulus-response materials, and nanoscale energy harvesting schemes based on photoswitch-modified biomolecules such as DNA.- Published
- 2016
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21. Local Density Fluctuations Predict Photoisomerization Quantum Yield of Azobenzene-Modified DNA.
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Kingsland A, Samai S, Yan Y, Ginger DS, and Maibaum L
- Subjects
- Molecular Dynamics Simulation, Photochemical Processes, Quantum Theory, Stereoisomerism, Azo Compounds chemistry, DNA chemistry
- Abstract
Azobenzene incorporated into DNA has a photoisomerization quantum yield that depends on the DNA sequence near the azobenzene attachment site. We use Molecular Dynamics computer simulations to elucidate which physical properties of the modified DNA determine the quantum yield. We show for a wide range of DNA sequences that the photoisomerization quantum yield is strongly correlated with the variance of the number of atoms in close proximity to the outer phenyl ring of the azobenzene group. We infer that quantum yield is controlled by the availability of fluctuations that enable the conformational change. We demonstrate that these simulations can be used as a qualitative predictive tool by calculating the quantum yield for several novel DNA sequences, and confirming these predictions using UV-vis spectroscopy. Our results will be useful for the development of a wide range of applications of photoresponsive DNA nanotechnology.
- Published
- 2016
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22. A light responsive two-component supramolecular hydrogel: a sensitive platform for the fabrication of humidity sensors.
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Samai S, Sapsanis C, Patil SP, Ezzeddine A, Moosa BA, Omran H, Emwas AH, Salama KN, and Khashab NM
- Abstract
The supramolecular assembly of anionic azobenzene dicarboxylate and cationic cetyltrimethylammonium bromide (CTAB) formed a stimuli responsive hydrogel with a critical gelation concentration (CGC) of 0.33 wt%. This self-sustainable two-component system was able to repair damage upon light irradiation. Moreover, it was successfully employed in the fabrication of highly sensitive humidity sensors for the first time.
- Published
- 2016
- Full Text
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23. Nickel oxide thin film from electrodeposited nickel sulfide thin film: peroxide sensing and photo-decomposition of phenol.
- Author
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Jana S, Samai S, Mitra BC, Bera P, and Mondal A
- Abstract
A novel non-enzymatic peroxide sensor has been constructed by using nickel oxide (NiO) thin films as sensing material, which were prepared by a two-step process: (i) electrodeposition of nickel sulfide (NiS) and (ii) thermal air oxidation of as-deposited NiS to NiO. The resultant material is highly porous and comprises interconnected nanofibers. UV-Vis spectroscopy, FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) were used for a complete characterization of nanostructured NiO thin films. Cyclic voltammetry study shows that NiO/ITO electrode facilitates the oxidation of hydrogen peroxide and exhibits excellent catalytic activity towards its sensing. The amperometric study of NiO/ITO was carried out to determine the sensitivity, linear range, detection limit of the proposed sensor. The sensor exhibits prominent electrocatalytic activity toward the oxidation of H2O2 with a wide linear range and a low detection limit. The possible use of the synthesized NiO thin films as an effective photocatalyst for the decomposition of phenol is also discussed.
- Published
- 2014
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24. Does crystal or gel matter to stereochemistry of a reaction? Silver complexation-promoted solid-state [2+2] reaction of an unsymmetrical olefin.
- Author
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Samai S, Ghosh P, and Biradha K
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- Crystallography, X-Ray, Cycloaddition Reaction, Dimerization, Hydrogen Bonding, Molecular Conformation, Stereoisomerism, Alkenes chemistry, Coordination Complexes chemistry, Gels chemistry, Silver chemistry
- Abstract
Head-to-tail and head-to-head [2+2] photodimerization of an unsymmetrical olefin containing benzimidazole and pyridyl groups was achieved by irradiating Ag(I) complexed olefin in crystalline state and gel state, respectively, in stereoselective manner. The [2+2] reaction indicates that the molecular arrangement in a gel is different from that of a xerogel.
- Published
- 2013
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25. Nanoscopic Amyloid Pores Formed via Stepwise Protein Assembly.
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Bhattacharya M, Jain N, Dogra P, Samai S, and Mukhopadhyay S
- Abstract
Protein aggregation leading to various nanoscale assemblies is under scrutiny due to its implications in a broad range of human diseases. In the present study, we have used ovalbumin, a model non-inhibitory serpin, to elucidate the molecular events involved in amyloid assembly using a diverse array of spectroscopic and imaging tools such as fluorescence, laser Raman, circular dichroism spectroscopy, and atomic force microscopy (AFM). The AFM images revealed a progressive morphological transition from spherical oligomers to nanoscopic annular pores that further served as templates for higher-order supramolecular assembly into larger amyloid pores. Raman spectroscopic investigations illuminated in-depth molecular details into the secondary structural changes of the protein during amyloid assembly and pore formation. Additionally, Raman measurements indicated the presence of antiparallel β-sheets in the amyloid core. Overall, our studies revealed that the protein conformational switch in the context of the oligomers triggers the hierarchical assembly into nanoscopic amyloid pores. Our results will have broad implications in the structural characterization of amyloid pores derived from a variety of disease-related proteins.
- Published
- 2013
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26. Quantifying ecosystem service trade-offs: the case of an urban floodplain in Vienna, Austria.
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Sanon S, Hein T, Douven W, and Winkler P
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- Agriculture, Algorithms, Austria, Cities, Drinking Water, Ecosystem, Fisheries, Recreation, Conservation of Natural Resources methods, Decision Support Techniques, Environmental Policy, Rivers, Wetlands
- Abstract
Wetland ecosystems provide multiple functions and services for the well-being of humans. In urban environments, planning and decision making about wetland restoration inevitably involves conflicting objectives, trade-offs, uncertainties and conflicting value judgments. This study applied trade-off and multi criteria decision analysis to analyze and quantify the explicit trade-offs between the stakeholder's objectives related to management options for the restoration of an urban floodplain, the Lobau, in Vienna, Austria. The Lobau has been disconnected from the main channel of the Danube River through flood protection schemes 130 years ago that have reduced the hydraulic exchange processes. Urban expansion has also changed the adjacent areas and led to increased numbers of visitors, which hampers the maximum potential for ecosystem development and exerts additional pressure on the sensitive habitats in the national park area. The study showed that increased hydraulic connectivity would benefit several stakeholders that preferred the ecological development of the floodplain habitats. However, multiple uses including fishery, agriculture and recreation, exploring the maximum potential in line with national park regulations, were also possible under the increased hydraulic connectivity options. The largest trade-offs were quantified to be at 0.50 score between the ecological condition of the aquatic habitats and the drinking water production and 0.49 score between the ecological condition of the terrestrial habitats and the drinking water production. At this point, the drinking water production was traded-off with 0.40 score, while the ecological condition of the aquatic habitats and the ecological condition of the terrestrial habitats were traded off with 0.30 and 0.23 score, respectively. The majority of the stakeholders involved preferred the management options that increased the hydraulic connectivity compared with the current situation which was not preferred by any stakeholders. These findings highlight the need for targeted restoration measures. By that, it is recommended that additional measures to ensure reliable drinking water production should be developed, if the higher connectivity options would be implemented. In the next step it is recommended to include cost and flood risk criteria in the decision matrix for more specific developed measures. The research showed that pair-wise trade-off figures provided a useful means to elaborate and quantify the real trade-offs. Finally, the research also showed that the use of multi criteria decision analyses should be based on a participatory approach, in which the process of arriving at the final ranking should be equal or more important than the outcome of the ranking itself., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
27. One-pot two-component [3 + 2] cycloaddition/annulation protocol for the synthesis of highly functionalized thiophene derivatives.
- Author
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Nandi GC, Samai S, and Singh MS
- Subjects
- Kinetics, Pyridines chemistry, Chemistry Techniques, Synthetic methods, Thiophenes chemical synthesis, Thiophenes chemistry
- Abstract
An efficient and experimentally rapid protocol for the synthesis of hitherto unreported 2,3-dicarboalkoxy-4-aroyl/heteroaroyl/alkanoyl thiophenes has been developed via 1-2 (C-S) and 3-4 (C-C) bond connections promoted by 4-dimethylaminopyridine (DMAP). Optimally, the reaction takes only 3-5 min when β-oxodithioester and dialkyl acetylenedicarboxylate are stirred in DCM at room temperature in the presence of DMAP. This method allows a clean and general synthesis of previously inaccessible and synthetically demanding thiophenes containing the ferrocenyl group. The speed, experimental ease, and high yields of this process are improvements over existing methods to access this important substructure.
- Published
- 2011
- Full Text
- View/download PDF
28. Regioselective synthesis of tetrahydrothiochromen-5-ones via a one-pot three-component solvent-free domino protocol.
- Author
-
Chowdhury S, Nandi GC, Samai S, and Singh MS
- Abstract
A highly efficient one-pot three-component regioselective synthesis of 4-aryl-3-aroyl-2-methylsulfanyl-4,6,7,8-tetrahydrothiochromen-5-ones has been developed by annulation of β-oxodithioesters with aldehydes and cyclic 1,3-diketones under solvent-free conditions promoted by P(2)O(5). No cocatalyst or activator is needed in this protocol. The merit of this process is highlighted by its high efficiency of producing three new bonds and a stereocenter in one operation., (© 2011 American Chemical Society)
- Published
- 2011
- Full Text
- View/download PDF
29. Biginelli and Hantzsch-type reactions leading to highly functionalized dihydropyrimidinone, thiocoumarin, and pyridopyrimidinone frameworks via ring annulation with β-oxodithioesters.
- Author
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Nandi GC, Samai S, and Singh MS
- Subjects
- Catalysis, Magnetic Resonance Spectroscopy, Molecular Structure, Uracil chemistry, Coumarins chemical synthesis, Coumarins chemistry, Heterocyclic Compounds chemical synthesis, Heterocyclic Compounds chemistry, Pyrimidinones chemical synthesis, Pyrimidinones chemistry, Sulfhydryl Compounds chemical synthesis, Sulfhydryl Compounds chemistry, Uracil analogs & derivatives
- Abstract
An efficient and highly convergent route to dihydropyrimidinones (DHPMs) and hitherto unreported dihydropyridopyrimidinones has been developed by one-pot, three-component cyclocondensation of aromatic aldehydes, β-oxodithioesters, and urea/6-amino-1,3-dimethyluracil in the presence of recyclable SiO2-H2SO4. On the other hand, salicylaldehyde, β-oxodithioester, and urea reacted under similar conditions to afford the 3-aroyl/heteroaroyl-2H-chromen-2-thiones in high yields instead of Biginelli product. The attractive feature of this approach is the synthesis of three important bioactive heterocyclic frameworks from the same β-oxodithioester under the similar reaction conditions, making this new strategy highly useful in diversity-oriented synthesis (DOS).
- Published
- 2010
- Full Text
- View/download PDF
30. Relative fatigability of muscles in response to repetitive nerve stimulation in myasthenia gravis.
- Author
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Witoonpanich R, Barakul S, and Dejthevaporn C
- Subjects
- Adolescent, Adult, Aged, Female, Humans, Male, Middle Aged, Myasthenia Gravis diagnosis, Sensitivity and Specificity, Electric Stimulation, Muscle Fatigue physiology, Muscle, Skeletal physiopathology, Myasthenia Gravis physiopathology
- Abstract
Background: Repetitive nerve stimulation (RNS) plays an important role in the diagnosis of myasthenia gravis (MG). Technically, this test can be more easily performed on distal muscles than proximal muscles. On the other hand, proximal muscles have been shown to be more easily fatigued or more sensitive than the distal ones., Objective: Evaluate the relative fatigability of different muscles in response to RNS in ocular and generalized MG patients., Material and Method: Two hundred patients with 44 ocular MG and 156 generalized MG were studied The relative fatigability of each muscle was calculated as percentage of cases with abnormal response. A decrement of 10% or more of the amplitude of the compound muscle action potentials was considered abnormal., Result: The cases with abnormal response of adductor digiti minimi, anconeus, trapezius, nasalis and orbicularis oculi were 17%, 50%, 55%, 62%, 66% in ocular MG and 53%, 77%, 79%, 85%, 79% in generalized MG respectively. These results showed that in generalized MG the response in all the muscles was more frequently abnormal and was fatigable in a more comparable degree, whereas in ocular MG, the facial muscles were more often abnormal than the limb muscles., Conclusion: The abnormal response because of fatigability was more widespread in generalized MG whereas facial muscles were relatively more sensitive in ocular MG. This finding may be useful for the selection of the muscles to be tested in RNS especially in ocular MG.
- Published
- 2006
31. Bioequivalence study of postcoital emergency contraceptions containing levonorgestrel.
- Author
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Chompootaweep S and Leepipatpibul S
- Subjects
- Adult, Female, Humans, Therapeutic Equivalency, Contraceptives, Postcoital, Synthetic, Levonorgestrel pharmacokinetics, Norgestrel pharmacokinetics
- Abstract
Objective: The progestogen-only method of emergency contraception, levonorgestrel, is one of the effectiveness in preventing expected pregnancies. The comparative bioavailability was carried out on levonorgestrel tablets (0.75 mg) from two different sources (Hungarian and Thai made)., Method: Eighteen healthy female volunteers were given a single oral dose of 0.75 mg tablets in a crossover design. Serum levonorgestrel concentration was determined by radio-immunoassay. The pharmacokinetic analysis of serum levonorgestrel concentration from each treatment was established. The comparative bioavailability of the two products was determined by the analysis of variance (ANOVA) for two way crossover design., Results: The results found that the mean peak (X +/- SD) serum concentration (Cmax) of the Thai-made pill and Hungarian-pill were 1.18 +/- 0.12 and 1.14 +/- 0.10 ng/ml, respectively. The 90% confidence intervalfor the difference of log Cmax mean was 99.54-120.78%. The time to peak serum concentration (Tmax) of the Thai-made pill and Hungarian-pill were 1.56 +/- 0.73 and 1.58 +/- 0.67 hrs, respectively. The different time of peak serum levonorgestrel concentration was 1.27%. The mean area under the curve (AUC) of Thai-made pill and Hungarian-pill were 2.14 +/- 0.21 and 2.09 +/- 0.16 ng.h/ml, respectively. The 90% confidence interval for the difference of log AUC mean was 103.27 - 121.89%., Conclusion: The present study revealed that the 90% confidence interval for the difference of log Cmax mean and log AUC mean were in the criteria of acceptance, which should be within 80-125%. So, the authors can conclude that the Thai-made pill was bioequivalent to the Hungarian-pill.
- Published
- 2004
32. Day 3 serum inhibin B level of poor and good ovarian responders in the IVF-program.
- Author
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Tharnprisarn W, Leepipatpaiboon S, Boonkasemsanti W, and Virutamasen P
- Subjects
- Adult, Enzyme-Linked Immunosorbent Assay methods, Female, Humans, Fertilization in Vitro, Inhibins blood, Ovulation Detection methods
- Abstract
The aim of this study was to compare day-3 serum inhibin B levels of poor and good ovarian responders in the IVF-program. The study group consisted of 20 poor ovarian responders. The control group composed of 40 good ovarian responders who had similar demographic characteristics. The serum inhibin B levels were analysed by two-site-immunosorbent assay or sandwich ELISA (Enzyme Linked ImmunoSorbent Assay). The mean inhibin B level of the study group was 113.18 +/- 57.96 picogram per millilitre and of the control group was 94.05 +/- 61.81 picogram per millilitre. There was no statistically significant difference. The results might be useful as base-line data for further study.
- Published
- 2002
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