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Ahmad A, Ullah S, Khan A, Ahmad W, Khan AU, Khan UA, Rahman AU, Yuan Q. Graphene oxide selenium nanorod composite as a stable electrode material for energy storage devices. APPLIED NANOSCIENCE 2019. [DOI: 10.1007/s13204-019-01204-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Shams S, Khan AU, Yuan Q, Ahmad W, Wei Y, Khan ZUH, Shams S, Ahmad A, Rahman AU, Ullah S. Facile and eco-benign synthesis of Au@Fe2O3 nanocomposite: Efficient photocatalytic, antibacterial and antioxidant agent. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 199:111632. [DOI: 10.1016/j.jphotobiol.2019.111632] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/17/2019] [Accepted: 09/12/2019] [Indexed: 10/26/2022]
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Shah FA, Kury LA, Li T, Zeb A, Koh PO, Liu F, Zhou Q, Hussain I, Khan AU, Jiang Y, Li S. Polydatin Attenuates Neuronal Loss via Reducing Neuroinflammation and Oxidative Stress in Rat MCAO Models. Front Pharmacol 2019; 10:663. [PMID: 31293416 PMCID: PMC6606791 DOI: 10.3389/fphar.2019.00663] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 05/23/2019] [Indexed: 12/14/2022] Open
Abstract
Ischemic stroke is characterized by permanent or transient obstruction of blood flow, which initiates a cascading pathological process, starting from acute ATP loss and ionic imbalance to subsequent membrane depolarization, glutamate excitotoxicity, and calcium overload. These initial events are followed by neuroinflammation and oxidative stress, eventually causing neuronal neurosis and apoptosis. Complicated interplays exist between these steps happening across various stages, which not only represent the complicated nature of ischemic pathology but also warrant a detailed delineation of the underlying molecular mechanisms to develop better therapeutic options. In the present study, we examined the neuroprotective effects of polydatin against ischemic brain injury using a rat model of permanent middle cerebral artery occlusion (MCAO). Our results demonstrated that polydatin treatment reduced the infarction volume and mitigated the neurobehavioral deficits, sequentially rescued neuronal apoptosis. Ischemic stroke induced an elevation of neuroinflammation and reactive oxygen species, which could be attenuated by polydatin via the reduced activation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase. In addition, polydatin upregulated the endogenous antioxidant nuclear factor erythroid 2-related factor 2, heme oxygenase-1, the thioredoxin pathway, and eventually reversed ischemic-stroke-induced elevation of ROS and inflammation in ischemic cortical tissue. The diverse and broad actions of polydatin suggested that it could be a multiple targeting neuroprotective agent in ameliorating the detrimental effects of MCAO, such as neuroinflammation, oxidative stress, and neuronal apoptosis. As repetitive clinical trials of neuroprotectants targeting a single step of stroke pathological process have failed previously, our results suggested that a neuroprotective strategy of acting at different stages may be more advantageous to intervene in the vicious cycles in MCAO.
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Khan AU, Hossain MA, Rahman MA, Rahman HW, Reza MA, Khan MK, Mahmud AA. Estimation of Vitamin D levels among Physicians Working in a Tertiary Level Hospital of Bangladesh. Mymensingh Med J 2019; 28:322-327. [PMID: 31086146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Vitamin D is essential for the body to regulate calcium and phosphate levels and mineralization of bone. It is synthesized in the skin after ultraviolet radiation exposure or obtained in the diet to a less extent. Vitamin D deficiency is attracting attention due to higher prevalence in different populations. Physicians of Bangladesh are supposed to be vulnerable to low Vitamin D levels owing to long indoor work hours in both government and private settings. The study was conducted to evaluate Vitamin D status among physicians working in a tertiary level public hospital of Bangladesh. The cross sectional descriptive study was carried out at Mymensingh Medical College Hospital during the period of January 2018 to June 2018. Data were collected from purposively selected 102 doctors of different levels using a case record form. Interview, measurements and laboratory investigations were done accordingly. Vitamin D levels were categorized as deficient (<20.00ng/L), Insufficient (20.00-29.00ng/L), Sufficient (30.00-100.00ng/L) and Potential Toxicity (>100.00ng/L). Among 102 doctors 79(77.5%) were male and 23(22.5%) were female. Maximum (60.8%) were in the age group of 31 years to 50 years. Mean±SD age of the subjects was 49.9±3.61years. Vitamin D deficiency was found in 19(18.6%) subjects and insufficiency was in 49(48.0%) of the subjects. On the other hand 34(33.3%) subjects had sufficient Vitamin D levels. Potential Vitamin D toxicity was not found in any of the subjects. Vitamin D deficiency was found more in female (30.4%) than male (15.2%) but insufficiency was found more in male (50.6%) than female (39.1%). The study revealed that 66.6% physicians had either deficiency or insufficiency of Vitamin D. Exposure to sunlight, dietary intake and Vitamin D supplementation should be considered to increase the status of Vitamin D levels in Physicians of Bangladesh.
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Rahman AU, Khan AU, Yuan Q, Wei Y, Ahmad A, Ullah S, Khan ZUH, Shams S, Tariq M, Ahmad W. Tuber extract of Arisaema flavum eco-benignly and effectively synthesize silver nanoparticles: Photocatalytic and antibacterial response against multidrug resistant engineered E. coli QH4. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 193:31-38. [PMID: 30802773 DOI: 10.1016/j.jphotobiol.2019.01.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/16/2019] [Accepted: 01/29/2019] [Indexed: 10/27/2022]
Abstract
Metal nanoparticles, synthesized using Phyto-constituents are the most economically and environmentally benign materials ever. Biogenic silver nanoparticles (AgNPs) from three fractions of Arisaema flavum tuber extract were synthesized and characterized by UV-visible spectroscopy, XRD (X-rays diffraction), FT-IR (Fourier transform infrared spectroscopy) TEM (transmission electron microscopy) and EDX (Energy dispersive Microscopy). XRD pattern show the face centred cubic crystalline (Fcc) structure of AgNPs. FTIR spectra confirmed the presence of different Polyphenolic compounds capping the AgNps. UV-visible spectroscopy result confirmed the presence of Ag because of the particular surface plasmon Resonance (SPR) in the area of 400-430 nm. The electron microscope studies revealed the formation of spherical AgNPs with diameter ranging from 12 nm to 20 nm. Strong signals of AgNPs were confirmed with EDX analysis. The antibacterial properties of the AgNPs prepared with various extracts were tested against multi-drug resistant bacteria. Which showed significant antibacterial activity against all the multidrug resistant bacterial strains and especially multidrug resistant engineered E.ColiQH4. AgNPs synthesized by methanolic, Ethyl Acetate and aqueous Extracts of Areseama Flavum exhibited significant Photocatalytic activity to reduce methylene blue. Small size, spherical shape and high dispersion are the key properties due to which the AgNPs are having significant biological and photocatalytic activity. To the best of our knowledge, it is the first report of biogenic AgNPs regarding antibacterial activity against multidrug resistant Engineered E.Coli QH4.
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Idrees MA, Younus M, Farooqi SH, Khan AU. Retraction notice to "Blackleg in cattle: Current understanding and future research perspectives- A review" [Microbial Pathogenesis 120 (2018) 176-180]. Microb Pathog 2019; 126:407. [PMID: 30704615 DOI: 10.1016/j.micpath.2018.12.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Sadiq MA, Khan AU, Saleem S, Nadeem S. Numerical simulation of oscillatory oblique stagnation point flow of a magneto micropolar nanofluid. RSC Adv 2019; 9:4751-4764. [PMID: 35514636 PMCID: PMC9060680 DOI: 10.1039/c8ra09698h] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 01/25/2019] [Indexed: 11/21/2022] Open
Abstract
The particular inquiry is made to envision the characteristics of magneto-hydrodynamic oscillatory oblique stagnation point flow of micropolar nanofluid. The applied magnetic field is assumed parallel towards isolating streamline. A relative investigation is executed for copper and alumina nanoparticles while seeing water type base fluid. To be more specific, in the presence of both weak and strong concentration, the physical situation of micropolar fluid is mathematically modeled in terms of differential equations. The transformed mixed system is finally elucidated by midpoint method with the Richardson extrapolation development and shooting mechanism with fifth order R–K Fehlberg technique. The impact of governing parameters are shown and explored graphically. The obtained results are compared with existing published literature. Moreover, it is found that the magnetic susceptibility of nanofluids shows provoking nature towards copper as compared to Alumina. Also it is perceived that Cu–water shows higher wall shear stress and heat transfer rate than Al2O3–water. Additional, the thickness of momentum boundary layer is thin for weak concentration as related to strong concentration. The particular inquiry is made to envision the characteristics of magneto-hydrodynamic oscillatory oblique stagnation point flow of micropolar nanofluid.![]()
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Hayat T, Nadeem S, Khan AU. Rotating flow of Ag-CuO/H 2O hybrid nanofluid with radiation and partial slip boundary effects. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2018; 41:75. [PMID: 29926290 DOI: 10.1140/epje/i2018-11682-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
The main object of the present paper is to examine and compare the improvement of flow and heat transfer characteristics between a rotating nanofluid and a newly discovered hybrid nanofluid in the presence of velocity slip and thermal slip. The influence of thermal radiation is also included in the present study. The system after applying the similarity transformations is solved numerically by using the bvp-4c scheme. Additionally, numerical calculations for the coefficient of skin friction and local Nusselt number are introduced and perused for germane parameters. The comparison between water, nanofluid and hybrid nanofluid on velocity and temperature is also visualized. It is observed that the velocity and temperature distributions are decreasing functions of the slip parameter. Temperature is boosted by thermal radiation and rotation. It is found that the heat transfer rate of the hybrid nanofluid is higher as compared to the traditional nanofluid.
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Ullah S, Ahmad A, Subhan F, Jan A, Raza M, Khan AU, Rahman AU, Khan UA, Tariq M, Yuan Q. Tobramycin mediated silver nanospheres/graphene oxide composite for synergistic therapy of bacterial infection. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 183:342-348. [DOI: 10.1016/j.jphotobiol.2018.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/02/2018] [Accepted: 05/05/2018] [Indexed: 01/26/2023]
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Khan AU, Yuan Q, Khan ZUH, Ahmad A, Khan FU, Tahir K, Shakeel M, Ullah S. An eco-benign synthesis of AgNPs using aqueous extract of Longan fruit peel: Antiproliferative response against human breast cancer cell line MCF-7, antioxidant and photocatalytic deprivation of methylene blue. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 183:367-373. [DOI: 10.1016/j.jphotobiol.2018.05.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 05/02/2018] [Accepted: 05/05/2018] [Indexed: 01/17/2023]
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Idrees MA, Younus M, Farooqi SH, Khan AU. Blackleg in cattle: Current understanding and future research perspectives- A review. Microb Pathog 2018; 120:176-180. [PMID: 29733903 DOI: 10.1016/j.micpath.2018.04.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 04/21/2018] [Accepted: 04/23/2018] [Indexed: 11/29/2022]
Abstract
Blackleg is an endogenous acute infection that principally affects cattle. The disease is caused by Clostridium chauvoei (C. chauvoei), an anaerobic spore forming bacterium. Control of this disease is based on stringent husbandry measures and scheduled vaccination plan. In recent years, the major virulence factors of C. chauvoei have been discovered and described. However, the pathogenesis of blackleg in cattle and in particular, circulation of the pathogen from point of entry to target tissues is yet not fully elucidated. This review summarizes the latest review of literature that significantly contributed for understanding the disease in cattle, and provides a foundation to preventive strategies.
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Shakeel M, Arif M, Yasin G, Li B, Khan AU, Khan FU, Baloch MK. Hollow mesoporous architecture: A high performance Bi-functional photoelectrocatalyst for overall water splitting. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.02.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Rouf MA, Khan M, Sharif JU, Karim MR, Rahman MM, Ahmed H, Pandit H, Khan AU, Rahman MA, Talukder RK, Parveen R, Akhter H. Prevalence of GERD in Type II Diabetes Mellitus Patients Admitted in A Tertiary Care Hospital of Bangladesh. Mymensingh Med J 2017; 26:710-715. [PMID: 29208856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Gastroesophageal reflux disease (GERD) is defined as symptoms or complications associated with regurgitation from the stomach and/or the duodenum to the esophagus. Patients with type II diabetes mellitus (DM) were known to have higher prevalence of GERD in the Western countries, but data on the impact of GERD on DM patients in our country are scarce. The aim of this cross-sectional study was to evaluate the presence of GERD in type II DM patients admitted at the Department of Medicine, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from April 2015 to September 2015. A total of 137 type II DM cases were purposively collected. Reflux Disease Questionnaire (RDQ) was used to check the presence of GERD. Patient's characteristics, laboratory data, face-to-face interview data were analyzed. Out of 137 type 2 DM patients 108 were suffering from GERD giving a prevalence rate of 78.8% which is quite high. Pathophysiological factors like age, sex, duration of DM, weight, waist circumference (WC) had no significant difference between GERD-DM and non-GERD-type II DM patients. Only hypertension and frequent eating fatty food were found to have significant differences between the two groups. From the study findings it could be said that the higher rate of GERD in patients with type II DM may be associated with lifestyle factor and some pathophysiological factors like hypertension. Psychiatric factors may also play role in contributing GERD. Further in-depth and large scale studies are necessary in our country in this regard.
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Khan ZUH, Khan A, Chen Y, Shah NS, Muhammad N, Khan AU, Tahir K, Khan FU, Murtaza B, Hassan SU, Qaisrani SA, Wan P. Biomedical applications of green synthesized Nobel metal nanoparticles. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 173:150-164. [DOI: 10.1016/j.jphotobiol.2017.05.034] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 05/23/2017] [Accepted: 05/23/2017] [Indexed: 11/26/2022]
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Islam MS, Uddin MZ, Ali MS, Islam MN, Rahman MH, Robi IH, Haque MM, Rahman MW, Uddin MA, Ahamed F, Malek MS, Kabir MA, Rahman MS, Khan AU, Doel FA. Modified Blatchford Score for Risk Stratification in Adult Patient with Nonvariceal Upper Gastrointestinal Haemorrhage and Their Short Term Hospital Outcome. Mymensingh Med J 2017; 26:490-497. [PMID: 28919600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Upper gastrointestinal hemorrhage (UGIH) is one of the most common and life-threatening gastrointestinal emergency. There are several risk scores for risk stratification in UGIB patients. The Modified Blatchford score, which relies only on clinical and laboratory parameters, is practical in the emergency setting The Modified Blatchford scoring system also known as Glasgow Blatchford Scoring (GBS) have been developed to stratify risk of non variceal upper gastrointestinal hemorrhage or need of medical or surgical intervention, endoscopic therapy. Objective of this study is to see risk stratification by The Modified Blatchford score and short term hospital outcome in non variceal upper GI hemorrhage patients. The observational study was carried out over a period of 6 months from October, 2014 to March, 2015 in Department of Department of Medicine, Gastroenterology and Surgery Mymensingh Medical College Hospital, Mymensingh. A total of 120 patients with non variceal UGIH were taken for the study during study period. Categorical variables were reported as percentage and Means and proportions were carried out using the Chi-square test (X2-test) of different variables by SPSS software version-18.0. Patients related variables age, sex; and main outcome variables the Modified Blatchford scoring system, Risk stratification, and short term hospital outcome were observed. Age frequency among total cases were 66(55%) <60 years, 50(41.67%) from 60-79 years and 4(3.3%) 80 years or above and sex distribution were 84(70%) were male and 36(30%) were female patients. Blatchford score of patients 1(0.83%) had score 0, 1(0.83%) had score 1, 2(1.67%) had score 2, 2(1.67%) had score 3, 2(1.67%) had score 4, 3(2.5%) had score 5, 12(10%) had score 6; 15(12.5%) had score 7, 16(13.33%) had score 8, 17(14.17%) had score 9, 16(13.33%) had score 10, 15(12.5%) had score 11, 10(8.33%) had score 12, 4(3.33% ) had score 13, 1(0.83%) had score 14, 2(1.67%) had score 15 and 1(0.83%) had score 16. Risk stratification showed 54(45%) had low risk (Mean GBS score 6.19±1.79), 66(55%) had high risk (Mean GBS score 11.03±1.83) Outcome of the patients were observed that 1(0.83%) died, 54(45%) was discharged without any medical or surgical intervention, and 65(54.17%) patients' needs medical or surgical intervention such as blood transfusion and endoscopy. Among total 120 patients with upper GI hemorrhage I have found that GBS score of three or less than three is predictive of low risk of adverse outcomes and can be discharged without any intervention.
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Khan FU, Chen Y, Khan NU, Ahmad A, Tahir K, Khan ZU, Khan AU, Khan SU, Raza M, Wan P. Visible light inactivation of E. coli , Cytotoxicity and ROS determination of biochemically capped gold nanoparticles. Microb Pathog 2017; 107:419-424. [DOI: 10.1016/j.micpath.2017.04.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/14/2017] [Accepted: 04/19/2017] [Indexed: 12/23/2022]
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Khan ZUH, Khan A, Wan P, Khan AU, Tahir K, Muhammad N, Khan FU, Shah HU, Khan ZU. New natural product -an efficient antimicrobial applications of new newly synthesized pyrimidine derivatives by the electrochemical oxidation of hydroxyl phenol in the presence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol as nucleophile. Nat Prod Res 2017; 32:1161-1169. [PMID: 28494613 DOI: 10.1080/14786419.2017.1326043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Some new pyrimidine derivatives have been synthesised by electrochemical oxidation of catechol (1a) in the existence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol (3) as a nucleophile in aqueous solution using Cyclic Voltammetric and Controlled Potential Coulometry. The catechol has been oxidised to o-quinone through electrochemical method and participative in Michael addition reaction, leading to the development of some new pyrimidine derivatives. The products were achieved in good yield with high pureness. The mechanism of the reaction has been conformed from the Cyclic Voltammetric data and Controlled Potential Coulometry. After purification, the compounds were characterised using modern techniques. The synthesised materials were screened for antimicrobial actions using Gram positive and Gram negative strain of bacteria. These new synthesised pyrimidine derivatives showed very good antimicrobial activity.
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Tahir K, Nazir S, Ahmad A, Li B, Khan AU, Khan ZUH, Khan FU, Khan QU, Khan A, Rahman AU. Facile and green synthesis of phytochemicals capped platinum nanoparticles and in vitro their superior antibacterial activity. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 166:246-251. [DOI: 10.1016/j.jphotobiol.2016.12.016] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/05/2016] [Accepted: 12/10/2016] [Indexed: 11/25/2022]
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Tahir K, Nazir S, Li B, Ahmad A, Nasir T, Khan AU, Shah SAA, Khan ZUH, Yasin G, Hameed MU. Sapium sebiferum leaf extract mediated synthesis of palladium nanoparticles and in vitro investigation of their bacterial and photocatalytic activities. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 164:164-173. [PMID: 27689741 DOI: 10.1016/j.jphotobiol.2016.09.030] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/22/2016] [Indexed: 11/30/2022]
Abstract
There is a growing need to introduce eco-friendly and sustainable procedures for the synthesis of metal nanoparticles that include a mild reaction conditions, simple reaction setup, use of nontoxic medium such as water and plant extract, cost effectiveness as well as greater efficiency for biomedical and catalytic applications. For this purpose, small and highly dispersed palladium nanoparticles (PdNPs) were prepared by eco-friendly and cost effective green method using water soluble leaf extract of Sapium sebiferum as a reducing and capping agent. The formation of PdNPs was optimized at various temperatures i.e. (30°C, 60°C and 90°C) and different leaves extract (5mL and 10mL) in order to control their size and shape. The results indicated that PdNPs synthesized at 10mL leaf extract concentration and 60°C temperature have small sized (5nm) and spherical shape. The nanoparticles formation, their dispersion, size and shape were confirmed by various characterization techniques i.e. UV-Vis spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), thermo gravimetric analysis (TGA) and Dynamic light scattering technique (DLS) analysis. The biologically synthesized PdNPs were tested for size dependent photo degradation of methylene blue and inactivation of bacteria. The PdNPs synthesized at optimized condition (10mL extract concentration and 60°C) have strong photo catalytic activity and reduced 90% methylene blue in 70min. The optimized PdNPs also showed strong bacterial inhibition against Staphylococcus aureus 29(±0.8mm), Bacillus subtilis 19(±0.6mm) and pseudomonas aeruginosa 11(±0.6mm). The results of this examination demonstrate effective applications of extremely active PdNPs.
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Khan AU, Brož P, Premović M, Pavlů J, Vřeštál J, Yan X, Maccio D, Saccone A, Giester G, Rogl P. The Ti-Mn system revisited: experimental investigation and thermodynamic modelling. Phys Chem Chem Phys 2016; 18:23326-39. [PMID: 27498605 DOI: 10.1039/c6cp04542a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As the Ti-Mn phase diagram is part of numerous ternary and higher order systems of technological importance, the present paper defines phase relations which have been experimentally established throughout this work from 800 °C to the melting range based on Differential Thermal Analyses (DTA), X-ray powder diffraction, metallography and Electron Probe Micro Analysis (EPMA) techniques on ∼50 alloys, which were prepared by arc melting or high frequency melting under high purity argon starting from freshly cleaned metal ingots. Novel compounds were identified and reaction isotherms were redefined accordingly. In the Ti-rich region a novel compound TiMn was detected, sandwiched between the known phases: TiMn1-x (∼45 at% Mn) and TiMn1+x (∼55 at% Mn). In the Mn-rich region the hitherto unknown crystal structure of TiMn∼3 was solved from X-ray single crystal diffraction data and found to be of a unique structure type Ti6(Ti1-xMnx)6Mn25 (x = 0.462; space group Pbam (#55); a = 0.79081(3) nm, b = 2.58557(9) nm, c = 0.47931(2) nm), which consists of two consecutive layers of the hexagonal MgZn2-type Laves phase (TiMn2) and a combined layer of alternate structure blocks of MgZn2 type and Zr4Al3 type. Whereas TiMn can be considered as a line compound (solubility range <∼1 at%), the homogeneity regions of the Ti-Mn compounds are significant (determined by EPMA): TiMn1-x (44.0 to 46.6 at% Mn), TiMn1+x (54.6 to 56.3 at% Mn), Ti1+xMn2-x (MgZn2-type, 59 to 69 at% Mn at 1000 °C: -0.08 < x < 0.23), TiMn∼3 (unique type; 74 to 76.5 at% Mn) and TiMn∼4 (R-phase: Ti8(TixMn1-x)6Mn39, 80 to 84 at% Ti). Supported by ab initio calculations of the ground state energy for the Laves phase, the new experimental results enabled thermodynamic modelling of the entire Ti-Mn phase diagram providing a complete and novel set of thermodynamic data thus providing a sound basis for future thermodynamic predictions of higher order Ti-Mn-X-Y systems.
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Khan ZUH, Khan A, Shah A, Wan P, Chen Y, Khan GM, Khan AU, Tahir K, Muhammad N, Khan HU. Enhanced photocatalytic and electrocatalytic applications of green synthesized silver nanoparticles. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.04.082] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tahir K, Ahmad A, Li B, Nazir S, Khan AU, Nasir T, Khan ZUH, Naz R, Raza M. Visible light photo catalytic inactivation of bacteria and photo degradation of methylene blue with Ag/TiO2 nanocomposite prepared by a novel method. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 162:189-198. [PMID: 27376463 DOI: 10.1016/j.jphotobiol.2016.06.039] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 05/09/2016] [Accepted: 06/22/2016] [Indexed: 10/21/2022]
Abstract
Water purification is one of the worldwide problem and most of the conventional methods are associated with a number of drawbacks. Therefore it is the need of the day to develop new methods and materials to overcome the problem of water purification. In this research work we present a simple and green approach to synthesize silver decorated titanium dioxide (Ag/TiO2) nanocomposite with an efficient photo catalytic activities. Phytochemicals of the Cestrum nocturnum leaf extract were used to synthesize silver nanoparticles (AgNPs), Titanium dioxide (TiO2) and Ag/TiO2 nanocomposite. To confirm the formation, crystal structure, particle size and shape of green synthesized nanoparticles and nanocomposite, they were characterized by UV-visible spectroscopy (UV-vis), X-ray diffraction spectroscopy (XRD), high resolution transmission electron microscopy (HRTEM), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The AgNPs, TiO2 and Ag/TiO2 were evaluated for photo degradation of methylene blue (MB) and photo inhibition of Bacteria. The bio-synthesized Ag/TiO2 nanocomposite was observed to have strong catalytic activities for photo reduction of MB and photo inactivation of bacteria as compared to bare AgNPs and TiO2. In the presence of Ag/TiO2, 90% of MB was degraded only in 40min of irradiation. Alternatively the bare AgNPs and TiO2 degraded less than 30% and 80% respectively of MB even in more than 100min of irradiation. Similarly the Ag/TiO2 has very strong photo inhibition efficiency towards Escherichia coli and Pseudomonas aeruginosa. The zone of inhibition of irradiated Ag/TiO2 nanocomposites against E. coli and P. aeruginosa was 19mm and 17mm respectively which was two times higher than in dark. These promising photocatalytic activities of nanocomposite may be due to the highly decorated AgNPs over the surface of TiO2.
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Khan AU, Wei Y, Ahmad A, Haq Khan ZU, Tahir K, Khan SU, Muhammad N, Khan FU, Yuan Q. Enzymatic browning reduction in white cabbage, potent antibacterial and antioxidant activities of biogenic silver nanoparticles. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2015.12.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Khan AU, Wei Y, Haq Khan ZU, Tahir K, Ahmad A, Khan SU, Khan FU, Khan QU, Yuan Q. Visible light-induced photodegradation of methylene blue and reduction of 4-nitrophenol to 4-aminophenol over bio-synthesized silver nanoparticles. SEP SCI TECHNOL 2016. [DOI: 10.1080/01496395.2016.1140203] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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Hayashida Y, Umehira Y, Takatani K, Futami S, Kameda S, Kamata T, Khan AU, Takeuchi Y, Imai M, Yagi T. Cortical neural excitations in rats in vivo with using a prototype of a wireless multi-channel microstimulation system. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:1642-5. [PMID: 26736590 DOI: 10.1109/embc.2015.7318690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Understanding neural responses to multi-site electrical stimuli would be of essential importance for developing cortical neural prostheses. In order to provide a tool for such studies in experimental animals, we recently constructed a prototype of a wireless multi-channel microstimulation system, consisting of a stimulator chip, wireless data/power transmitters and receivers, and microcomputers. The proper operations of the system in cortical neural excitations were examined in anesthetized rats in vivo, with utilizing the voltage-sensitive dye imaging technique.
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