Breast cancer is a major health problem that affects more than 24% of women in Bangladesh. Furthermore, among low-income countries including Bangladesh, individuals have a high risk for developing breast cancer. This ...Breast cancer is a major health problem that affects more than 24% of women in Bangladesh. Furthermore, among low-income countries including Bangladesh, individuals have a high risk for developing breast cancer. This study aimed to identify candidate mitochondrial DNA (mtDNA) biomarkers for breast cancer diagnosis in Bangladeshi women to be used as a preventive approach. We screened the blood samples from 24 breast cancer patients and 20 healthy controls to detect polymorphisms in the D-loop and the ND3-and ND4-coding regions of mtDNA by direct sequencing. Among 14 distinct mutations, 10 polymorphisms were found in the D-loop, 3 were found in the ND3-coding region, and 1 was found in the ND4-coding region. The frequency of two novel polymorphisms in the D-loop, one at position 16290 (Tins) and the other at position 16293 (A-del), was higher in breast cancer patients than in control subjects (position 16290: odds ratio = 6.011, 95% confidence interval = 1.2482 to 28.8411, P = 0.002; position 16293: odds ratio = 5.6028, 95% confidence interval = 1.4357 to 21.8925, P = 0.010). We also observed one novel mutation in the ND3-coding region at position 10316 (A > G) in 69% of breast cancer patients but not in control subjects. The study suggests that two novel polymorphisms in the D-loop may be candidate biomarkers for breast展开更多
Objective:To investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh.Methods:The antibacterial activity was evaluated using disc diffusion assay ...Objective:To investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh.Methods:The antibacterial activity was evaluated using disc diffusion assay method against 12 bacteria(both gram positive and gram negative).The plant extracts were also screened for cytotoxic activity using the brine shrimp lethality bioassay method and the lethal concentrations(LC_(50))were determined at confidence intervals by analyzing the data on a computer loaded with"Finney Programme??Results:All the vegetable extracts showed low to elevated levels of antibacterial activity against most of the tested strains(zone of inhibition=5-28 mm).The most active extract against all bacterial strains was from Xanthium indicum which showed remarkable antibacterial activity having the diameter of growth inhibition zone ranging from 12 to 28 mm followed by Alternanthera sessilis(zone of inhibition=6-21 mm).All extracts exhibited considerable general toxicity towards brine shrimps.The LC_(50)value of the tested extracts was within the range of 8.447 to 60.323μg/mL with respect to the positive control(vincristine sulphate)which was 0.91μg/mL.Among all studied extracts,Xanthium indicum displayed the highest cytotoxic effect with LC_(50)value of 8.447μg/mL.Conclusions:The results of the present investigation suggest that most of the studied plants are potentially good source of antibacterial and anticancer agents.展开更多
Objective:To investigate the antioxidant,antimicrobial,cytotoxic and thrombolytic property of the fruits and leaves of Spondias dulcis（S.dulcis）.Methods:Methanolic extracts of fruits and leaves of S.dulcis were part...Objective:To investigate the antioxidant,antimicrobial,cytotoxic and thrombolytic property of the fruits and leaves of Spondias dulcis（S.dulcis）.Methods:Methanolic extracts of fruits and leaves of S.dulcis were partitioned with chloroform and dichloromethane.The antioxidant potential of the crude extract and partitioned fractions were evaluated in terms of total phenolic content,total flavonoid content,DPPH radical scavenging potential,reducing potential and total antioxidant capacity by specific standard procedures.The antimicrobial activity was evaluated using disc diffusion method.The cytotoxicity was evaluated by using brine shrimp lethality bioassay and compared with vincristine sulfate.The thrombolytic activity was compared with streptokinase.Results:The methanolic fruit extract exhibited the highest phenolic content,flavonoid content and antioxidant capacity,among the other extracts,with the highest DPPH radical scavenging activity at a concentration of 10μg/mL(IC50:1.91μg/mL)and maximum reducing power at a concentration of 100μg/ml.(EC50:3.58μg/mL).Though all extract showed moderate antimicrobial activity against the bacterial strains,weak or no activity against fungus.The range of LC50value of all extracts was 1.335-14.057μg/mL which was far lower than the cut off index for cytotoxicity.All extracts exhibited statistically significant（P【0.001）thrombolytic activity.Conclusions:Our study suggested that 5.dulcis exhibits antimicrobial activities against a wide variety of strains while it possesses significant antioxidant,cytotoxic and thrombolytic aclivily.展开更多
Objective:To investigate the bioactivities of crude n-hexane,ethyl acetate and methanol extracts of aerial part of Boerhavia diffusa Linn.(B.diffusa) and its phytochemical analysis.Methods: the identification of phylo...Objective:To investigate the bioactivities of crude n-hexane,ethyl acetate and methanol extracts of aerial part of Boerhavia diffusa Linn.(B.diffusa) and its phytochemical analysis.Methods: the identification of phyloconstituents and assay of antioxidant,thrombolytic,cytotoxic, antimicrobial activities were conducted using specific standard in vitro procedures.Results:The results showed that the plant extracts were a rich source of phytoconstituents.Methanol extract showed higher antioxidant,thrombolytic activity and less cytotoxic activity than those of n-hexane and ethyl acetate extracts of A diffusa.Among the bioactivities,antioxidant activity was the most notable compared to the positive control and thus could be a potential rich source of natural antioxidant.In case of antimicrobial screening,crude extracts of the plant showed remarkable antibacterial activity against tested microorganisms.All the extracts showed significant inhibitory activity against Candida albicuns,at a concentration of 1000 μg/disc.Conclusions:The present findings suggest that,the plant widely available in Bangladesh,could be a prominent source of medicinally important natural compounds.展开更多
The 3D reconstruction using deep learning-based intelligent systems can provide great help for measuring an individual’s height and shape quickly and accurately through 2D motion-blurred images.Generally,during the a...The 3D reconstruction using deep learning-based intelligent systems can provide great help for measuring an individual’s height and shape quickly and accurately through 2D motion-blurred images.Generally,during the acquisition of images in real-time,motion blur,caused by camera shaking or human motion,appears.Deep learning-based intelligent control applied in vision can help us solve the problem.To this end,we propose a 3D reconstruction method for motion-blurred images using deep learning.First,we develop a BF-WGAN algorithm that combines the bilateral filtering(BF)denoising theory with a Wasserstein generative adversarial network(WGAN)to remove motion blur.The bilateral filter denoising algorithm is used to remove the noise and to retain the details of the blurred image.Then,the blurred image and the corresponding sharp image are input into the WGAN.This algorithm distinguishes the motion-blurred image from the corresponding sharp image according to the WGAN loss and perceptual loss functions.Next,we use the deblurred images generated by the BFWGAN algorithm for 3D reconstruction.We propose a threshold optimization random sample consensus(TO-RANSAC)algorithm that can remove the wrong relationship between two views in the 3D reconstructed model relatively accurately.Compared with the traditional RANSAC algorithm,the TO-RANSAC algorithm can adjust the threshold adaptively,which improves the accuracy of the 3D reconstruction results.The experimental results show that our BF-WGAN algorithm has a better deblurring effect and higher efficiency than do other representative algorithms.In addition,the TO-RANSAC algorithm yields a calculation accuracy considerably higher than that of the traditional RANSAC algorithm.展开更多
The effects of source-drain underlaps on the performance of a top gate silicon nanowire on insulator transistor are studied using a three dimensional(3D) self-consistent Poisson-Schrodinger quantum simulation. Voltage...The effects of source-drain underlaps on the performance of a top gate silicon nanowire on insulator transistor are studied using a three dimensional(3D) self-consistent Poisson-Schrodinger quantum simulation. Voltage-controlled tunnel barrier is the device transport physics. The off current, the on/off current ratio, and the inverse subthreshold slope are improved while the on current is degraded with underlap. The physics behind this behavior is the modulation of a tunnel barrier with underlap. The underlap primarily affects the tunneling component of drain current. About 50% contribution to the gate capacitance comes from the fringing electric fields emanating from the gate metal to the source and drain. The gate capacitance reduces with underlap, which should reduce the intrinsic switching delay and increase the intrinsic cut-off frequency. However, both the on current and the transconductance reduce with underlap, and the consequence is the increase of delay and the reduction of cut-off frequency.展开更多
Background:Chukrasia velutina is an enthnomedicinally used plant reported to have significant medicinal values.The present study aimed to explore the pharmacological activities of bark methanol extract using in vitro,...Background:Chukrasia velutina is an enthnomedicinally used plant reported to have significant medicinal values.The present study aimed to explore the pharmacological activities of bark methanol extract using in vitro,in vivo and in silico models.Methods:The study was designed to investigate the pharmacological effects of methanol extract of Chukrasia velutina bark(MECVB)through in vitro,in vivo and in silico assays.Analgesic activity was tested using formalin-i nduced nociception and acetic acid-i nduced writhing assays while the antipyretic effect was tested using yeast-i nduced hyperthermia in mice model.The antioxidant effect was tested using the DPPH and reducing power assay and the cytotoxic screening was tested using the brine shrimp lethality bioassay.In addition,in silico studies were conducted using computer aided methods.Results:In the acetic acid-i nduced writhing assay,the extract showed 28.36%and 56.16%inhibition of writhing for doses of 200 and 400 mg/kg,respectively.Moreover,a dose-dependent formalin-i nduced licking response was observed in both early and late phase.In yeast-i nduced pyrexia,the MECVB exhibited(p<0.05)antipyretic effect.The extract demonstrated an ICvalue of 78.86μg/ml compared with ascorbic acid(IC23.53μg/ml)in the DPPH scavenging assay.The compounds sitosterol,5,7-dimethoxycoumarin and scopoletin were seen be effective in molecular docking scores against COX-I(2OYE),COX-II(6COX)and human peroxiredoxin 5(1HD2).In ADME/T analysis,5,7-dimethoxycoumarin and scopoletin satisfied Lipinski’s rule of five and thus are potential drug candidates.Conclusion:The bark of Chukrasia velutina showed significant analgesic and antipyretic properties and is a potential source of natural anti-oxidative agents.展开更多
To cope with the demand and supply of electrical load of an interconnected power system of a country, we need to forecast its demand in advance. In this paper, we use a fuzzy system to forecast electrical load on shor...To cope with the demand and supply of electrical load of an interconnected power system of a country, we need to forecast its demand in advance. In this paper, we use a fuzzy system to forecast electrical load on short-term basis. Here, we consider temperature, humidity, seasons of a year and time segments of a day as the parameters, which govern the demand of electrical load. For each of the parameter, we use several membership functions (MFs) and then apply the Mamdani rule on MFs and the output is determined by using the centroid method. Finally, the surface plot reveals the real scenario of the load demand. The difference between actual load and the output of the fuzzy system is found as +1.65% to -13.76%. The concept of the paper can be applied in interconnected power system of Bangladesh to reduce power loss, especially when generation is higher than the demand.展开更多
Power saving is one of the key factors of emerging 4G mobile network as well as in IEEE 802.16e wireless metropolitan area networks (Wireless MAN). An efficient power saving mechanism is the heart for the guarantee of...Power saving is one of the key factors of emerging 4G mobile network as well as in IEEE 802.16e wireless metropolitan area networks (Wireless MAN). An efficient power saving mechanism is the heart for the guarantee of a long operating lifetime for a mobile subscriber station (MS), because MSs are normally driven by rechargeable batteries. It is a vital factor for Base Station (BS) of the same network. One of the most important features of 5G mobile is the extension of battery energy 10 times greater than the present days. In this context, the evaluation of duration of sleep mode of BS or MS based on traffic load of a network is now a new era of research work. In this paper, such analysis has been done based on two statistical models: Poisson’s pdf and Engset pdf. The concept of complete sharing and partitioning of user group of teletraffic engineering is applied to measure the possibility of getting leisure time of BS or MS. Both the traffic models used in the paper are applicable in both limited and unlimited user network, i.e. in micro and fem to cellular network of 4G and 5G.展开更多
Internet of Things (IoT) has become a prevalent topic in the world of technology. It helps billion of devices to connect to the internet so that they can exchange data with each other. Nowadays, the IoT can be applied...Internet of Things (IoT) has become a prevalent topic in the world of technology. It helps billion of devices to connect to the internet so that they can exchange data with each other. Nowadays, the IoT can be applied in anything, from cellphones, coffee makers, cars, body sensors to smart surveillance, water distribution, energy management system, and environmental monitoring. However, the rapid growth of IoT has brought new and critical threats to the security and privacy of the users. Due to the millions of insecure IoT devices, an adversary can easily break into an application to make it unstable and steal sensitive user information and data. This paper provides an overview of different kinds of cybersecurity attacks against IoT devices as well as an analysis of IoT architecture. It then discusses the security solutions we can take to protect IoT devices against different kinds of security attacks. The main goal of this research is to enhance the development of IoT research by highlighting the different kinds of security challenges that IoT is facing nowadays, and the existing security solutions we can implement to make IoT devices more secure. In this study, we analyze the security solutions of IoT in three forms: secure authentication, secure communications, and application security to find suitable security solutions for protecting IoT devices.展开更多
<span style="font-family:Verdana;">In this study, two Cu</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-fami...<span style="font-family:Verdana;">In this study, two Cu</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">based catalysts with and without N doped carbon matrix, named N-Cu/CuO/C and Cu/CuO were synthesized via calcination of melamine-cupper acetate complex and cupper acetate at 500<span style="white-space:nowrap;">°</span>C under an inert atmosphere. The catalysts were characterized by X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and </span><span><span style="font-family:Verdana;">CHNS </span><span><span style="font-family:Verdana;">elemental analyzer</span><i><span style="font-family:Verdana;">.</span></i></span></span><span style="font-family:Verdana;"> The catalytic activity of both catalysts was evaluated</span><span style="font-family:Verdana;"> through the NaBH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> associated reduction of commercial textile dye named reactive black 5 (RB5). The kinetics of the reduction of reactive black 5 was also described by the pseudo-first-order kinetic equation. For the studied reduction, N-Cu/CuO/C exhibited enhanced catalytic activity both in conversion and kinetics (97% conv. in 315 sec) compared to that of by Cu/CuO/C (25% conv. in 1500 sec). Besides, N-Cu/CuO/C also demonstrated good reusability up to four consecutive cycles.</span></span></span></span>展开更多
Objective:This study is to investigate the medicinal value of methanolic extiact of the leaves of Musa sapientum var.sylvesteris in Bangladesh.Methods:Several biochemical assays,thin layer chormatogarphy and ultra-vio...Objective:This study is to investigate the medicinal value of methanolic extiact of the leaves of Musa sapientum var.sylvesteris in Bangladesh.Methods:Several biochemical assays,thin layer chormatogarphy and ultra-violet spectroscopy were used to detect the presence of various types of compounds in this extract.Antioxidant effects were measured by DPPH scavenging assay,total reducing assay and hydrogen peroxide scavenging assay.Receptor binding activities and hydrogen peroxide induced hemolysis assay were performed by hemagglutination assay and hemolysis assay using erythrocytes.Disk diffusion assay was performed to show the antibacterial effect of the extract.Results:Alethanolic extract of the leaves showed antioxidant and antibacterial activity in ritro.The extract showed hemaglutination inhibition activities and hydrogen peroxide induced hemolysis inhibition activity of human red blood cells.Conclusion:Musa sapientum var.sylvesteris can be an useful medicinal plant.展开更多
This paper investigates the effect of inflow, outflow and shock waves in a single lane highway traffic flow problem. A constant source term has been introduced to demonstrate the inflow and outflow. The classical Ligh...This paper investigates the effect of inflow, outflow and shock waves in a single lane highway traffic flow problem. A constant source term has been introduced to demonstrate the inflow and outflow. The classical Lighthill Whitham and Richards (LWR) model combined with the Greenshields model is used to obtain analytical and numerical solutions. The model is treated as an IBVP and numerical solutions are presented using Lax Friedrichs scheme. Godunov method is also used to present shock wave analysis. The numerical procedures adopted in this investigation yield results which are very much consistent with real life scenario in terms of traffic density and velocity.展开更多
Atomistic quantum simulation is performed to compare the performance of zero-Schottky-barrier and doped source-drain contacts carbon nanotube field effect transistors(CNTFETs) with strain applied. The doped source-dra...Atomistic quantum simulation is performed to compare the performance of zero-Schottky-barrier and doped source-drain contacts carbon nanotube field effect transistors(CNTFETs) with strain applied. The doped source-drain contact CNTFETs outperform the Schottky contact devices with and without strain applied. The off-state current in both types of contact is similar with and without strain applied. This is because both types of contact offer very similar potential barrier in off-state. However, the on-state current in doped contact devices is much higher due to better modulation of on-state potential profile, and its variation with strain is sensitive to the device contact type. The on/off current ratio and the inverse subthreshold slope are better with doped source-drain contact, and their variations with strain are relatively less sensitive to the device contact type. The channel transconductance and device switching performance are much better with doped source-drain contact, and their variations with strain are sensitive to device contact type.展开更多
An innovative in-flight glass melting technology with thermal plasmas was developed for the purpose of energy conservation and environment protection. In this study, modelling and experiments of argon-oxygen induction...An innovative in-flight glass melting technology with thermal plasmas was developed for the purpose of energy conservation and environment protection. In this study, modelling and experiments of argon-oxygen induction thermal plasmas were conducted to investigate the melting behaviour of granulated soda-lime glass powders injected into the plasma. A two-dimensional local thermodynamic equilibrium （LTE） model was performed to simulate the heat and momentum transfer between plasma and particle. Results showed that the particle temperature was strongly affected by the flow rate of carrier gas and the particle size of raw material. A higher flow rate of carrier gas led to lower particle temperature and less energy transferred to particles which resulted in lower vitrification. The incomplete melting of large particles was attributed to the lower central temperature of the particle caused by a larger heat capacity. The numerical analysis explained well the experimental results, which can provide valuable practical guidelines for the process control in the melting process for the glass industry.展开更多
In this paper, an intuitive comparison of the computational performance of orthogonal frequency division multiplexing (OFDM) system has been made in terms of complex calculations required using different Fourier trans...In this paper, an intuitive comparison of the computational performance of orthogonal frequency division multiplexing (OFDM) system has been made in terms of complex calculations required using different Fourier transform techniques. The different transform techniques are introduced such as discrete Fourier transform (DFT) and various types of fast Fourier transform (FFT) as 2-radix FFT, 4-radix FFT etc. and the very recent very fast Fourier transform (VFFT). With intuitive mathematical analysis, it has been shown that with the reduced complexity that VFFT can offer, OFDM performance can be greatly improved in terms of calculations needed.展开更多
Use of different solvent systems for extraction of plant materials may cause variation in their bioactivities. The present study was conducted to evaluate the presence of different phytoconstituents and to compare in ...Use of different solvent systems for extraction of plant materials may cause variation in their bioactivities. The present study was conducted to evaluate the presence of different phytoconstituents and to compare in vitro bioactivities of petroleum ether, dichloromethane (DCM) and methanol extracts of Bombax ceiba (B. ceiba) roots available in Bangladesh. Preliminary phytochemical screening was conducted using specific standard procedure. Antioxidant activity of the extracts was evaluated using DPPH radical scavenging assay. Determination of total phenolic and flavonoid content was also carried out. Antibacterial and cytotoxic activities were investigated using disc diffusion method and brine shrimp lethality bioassay, respectively. All the experiments were carried out from February 2016 to September 2016. Phytochemical evaluation revealed the presence of alkaloids, terpenoids, carbohydrates, tannins, flavonoids, saponins and steroids. The methanol extract showed the highest DPPH radical scavenging activity and had the highest phenolic (187.42 ± 3.77 mg/g, GAE) and flavonoid content (74.67 ± 4 mg/g, QE) followed by the DCM and petroleum ether extracts. The extracts showed positive correlation between DPPH radical scavenging activity with the phenolic and flavonoid content. All the extracts showed mild to moderate in vitro antibacterial activity with zone of inhibition ranging from 7 mm to 13 mm. In brine shrimp lethality bioassay, the observed LC50 values for petroleum ether, DCM and methanol extracts were 70.72 μg/ml, 37.72 μg/ml and 22.58 μg/ml, respectively which revealed strong cytotoxic potential of the extracts compared to the positive control. The results indicated that B. ceiba roots could be a very potent source of natural radical scavenger and cytotoxic agent.展开更多
To enhance link capacity of a wireless link one or more repeater is used between the sender and the receiver. Recent literature deals with multiple parallel links to enhance throughput instead of conventional single p...To enhance link capacity of a wireless link one or more repeater is used between the sender and the receiver. Recent literature deals with multiple parallel links to enhance throughput instead of conventional single path. In case of a multidirectional and multi-hop wireless network, the selection of link of maximum signal to noise ratio (SNR) does not guarantee the maximum throughput. In this paper, we use augmenting path of Ford-Fulkerson algorithm in detection of maximum flow from sender to receiver. To reduce the process time at the sending node, minimum-cut theorem is used to determine maximum flow like power flow of previous work. Using the maximum flow algorithm, we obtain the capacity of multi-hop wireless link higher than the conventional theorem. The concept of the paper is applicable in MANET (Mobile Ad-hoc Network), WSN (Wireless Sensor Network) and CRN (Cognitive Radio Network).展开更多
The nonlinear propagation of dust-acoustic (DA) shock waves in three-component unmagnetized dusty plasma consisting of nonextensive electrons, Maxwellian ions and arbitrarily charged mobile dust grain has been investi...The nonlinear propagation of dust-acoustic (DA) shock waves in three-component unmagnetized dusty plasma consisting of nonextensive electrons, Maxwellian ions and arbitrarily charged mobile dust grain has been investigated. It is found that the presence of q-nonextensive electrons and ions can change the nonlinear behavior of shock wave. The standard reductive perturbation method is employed to study the basic features (phase speed, amplitude and width) of DA shock waves (DASWs) which are significantly modified by the presence of Maxwellian ions and nonextensive electrons. The present investigation can be very effective for understanding the nonlinear characteristics of the DASWs in space and laboratory dusty plasmas.展开更多
Energy efficiency plays vital roles in wireless communication system due to the “energy limited battery service” of a mobile station (MS). To ensure longer battery life in WiMAX, a new protocol has been introduced i...Energy efficiency plays vital roles in wireless communication system due to the “energy limited battery service” of a mobile station (MS). To ensure longer battery life in WiMAX, a new protocol has been introduced in its IEEE802.16m version. This new sleep mode has extended listening window and adjustable sleep cycle length. In this paper, we analyze the probability of attaining at three states: serving state, state of timer inactivity and silent state in a simplified statistical model using traffic parameters of arrival rate, pdf (probability density function) of interarrival time and its threshold value. Finally we developed a new state transition chain of the above three states of a MS of IEEE802.16m and solved the chain in closed form.展开更多
基金supported by grants from the Centre for Advanced Research in Sciences(CARS),University of Dhaka
文摘Breast cancer is a major health problem that affects more than 24% of women in Bangladesh. Furthermore, among low-income countries including Bangladesh, individuals have a high risk for developing breast cancer. This study aimed to identify candidate mitochondrial DNA (mtDNA) biomarkers for breast cancer diagnosis in Bangladeshi women to be used as a preventive approach. We screened the blood samples from 24 breast cancer patients and 20 healthy controls to detect polymorphisms in the D-loop and the ND3-and ND4-coding regions of mtDNA by direct sequencing. Among 14 distinct mutations, 10 polymorphisms were found in the D-loop, 3 were found in the ND3-coding region, and 1 was found in the ND4-coding region. The frequency of two novel polymorphisms in the D-loop, one at position 16290 (Tins) and the other at position 16293 (A-del), was higher in breast cancer patients than in control subjects (position 16290: odds ratio = 6.011, 95% confidence interval = 1.2482 to 28.8411, P = 0.002; position 16293: odds ratio = 5.6028, 95% confidence interval = 1.4357 to 21.8925, P = 0.010). We also observed one novel mutation in the ND3-coding region at position 10316 (A > G) in 69% of breast cancer patients but not in control subjects. The study suggests that two novel polymorphisms in the D-loop may be candidate biomarkers for breast
文摘Objective:To investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh.Methods:The antibacterial activity was evaluated using disc diffusion assay method against 12 bacteria(both gram positive and gram negative).The plant extracts were also screened for cytotoxic activity using the brine shrimp lethality bioassay method and the lethal concentrations(LC_(50))were determined at confidence intervals by analyzing the data on a computer loaded with"Finney Programme??Results:All the vegetable extracts showed low to elevated levels of antibacterial activity against most of the tested strains(zone of inhibition=5-28 mm).The most active extract against all bacterial strains was from Xanthium indicum which showed remarkable antibacterial activity having the diameter of growth inhibition zone ranging from 12 to 28 mm followed by Alternanthera sessilis(zone of inhibition=6-21 mm).All extracts exhibited considerable general toxicity towards brine shrimps.The LC_(50)value of the tested extracts was within the range of 8.447 to 60.323μg/mL with respect to the positive control(vincristine sulphate)which was 0.91μg/mL.Among all studied extracts,Xanthium indicum displayed the highest cytotoxic effect with LC_(50)value of 8.447μg/mL.Conclusions:The results of the present investigation suggest that most of the studied plants are potentially good source of antibacterial and anticancer agents.
基金Supported by the Department of Pharmacy of East West University,Dhaka,Bangladesh(Grant No.PHRM 404,SPRING 2011)
文摘Objective:To investigate the antioxidant,antimicrobial,cytotoxic and thrombolytic property of the fruits and leaves of Spondias dulcis（S.dulcis）.Methods:Methanolic extracts of fruits and leaves of S.dulcis were partitioned with chloroform and dichloromethane.The antioxidant potential of the crude extract and partitioned fractions were evaluated in terms of total phenolic content,total flavonoid content,DPPH radical scavenging potential,reducing potential and total antioxidant capacity by specific standard procedures.The antimicrobial activity was evaluated using disc diffusion method.The cytotoxicity was evaluated by using brine shrimp lethality bioassay and compared with vincristine sulfate.The thrombolytic activity was compared with streptokinase.Results:The methanolic fruit extract exhibited the highest phenolic content,flavonoid content and antioxidant capacity,among the other extracts,with the highest DPPH radical scavenging activity at a concentration of 10μg/mL(IC50:1.91μg/mL)and maximum reducing power at a concentration of 100μg/ml.(EC50:3.58μg/mL).Though all extract showed moderate antimicrobial activity against the bacterial strains,weak or no activity against fungus.The range of LC50value of all extracts was 1.335-14.057μg/mL which was far lower than the cut off index for cytotoxicity.All extracts exhibited statistically significant（P【0.001）thrombolytic activity.Conclusions:Our study suggested that 5.dulcis exhibits antimicrobial activities against a wide variety of strains while it possesses significant antioxidant,cytotoxic and thrombolytic aclivily.
文摘Objective:To investigate the bioactivities of crude n-hexane,ethyl acetate and methanol extracts of aerial part of Boerhavia diffusa Linn.(B.diffusa) and its phytochemical analysis.Methods: the identification of phyloconstituents and assay of antioxidant,thrombolytic,cytotoxic, antimicrobial activities were conducted using specific standard in vitro procedures.Results:The results showed that the plant extracts were a rich source of phytoconstituents.Methanol extract showed higher antioxidant,thrombolytic activity and less cytotoxic activity than those of n-hexane and ethyl acetate extracts of A diffusa.Among the bioactivities,antioxidant activity was the most notable compared to the positive control and thus could be a potential rich source of natural antioxidant.In case of antimicrobial screening,crude extracts of the plant showed remarkable antibacterial activity against tested microorganisms.All the extracts showed significant inhibitory activity against Candida albicuns,at a concentration of 1000 μg/disc.Conclusions:The present findings suggest that,the plant widely available in Bangladesh,could be a prominent source of medicinally important natural compounds.
基金the National Natural Science Foundation of China under Grant 61902311in part by the Japan Society for the Promotion of Science(JSPS)Grants-in-Aid for Scientific Research(KAKENHI)under Grant JP18K18044.
文摘The 3D reconstruction using deep learning-based intelligent systems can provide great help for measuring an individual’s height and shape quickly and accurately through 2D motion-blurred images.Generally,during the acquisition of images in real-time,motion blur,caused by camera shaking or human motion,appears.Deep learning-based intelligent control applied in vision can help us solve the problem.To this end,we propose a 3D reconstruction method for motion-blurred images using deep learning.First,we develop a BF-WGAN algorithm that combines the bilateral filtering(BF)denoising theory with a Wasserstein generative adversarial network(WGAN)to remove motion blur.The bilateral filter denoising algorithm is used to remove the noise and to retain the details of the blurred image.Then,the blurred image and the corresponding sharp image are input into the WGAN.This algorithm distinguishes the motion-blurred image from the corresponding sharp image according to the WGAN loss and perceptual loss functions.Next,we use the deblurred images generated by the BFWGAN algorithm for 3D reconstruction.We propose a threshold optimization random sample consensus(TO-RANSAC)algorithm that can remove the wrong relationship between two views in the 3D reconstructed model relatively accurately.Compared with the traditional RANSAC algorithm,the TO-RANSAC algorithm can adjust the threshold adaptively,which improves the accuracy of the 3D reconstruction results.The experimental results show that our BF-WGAN algorithm has a better deblurring effect and higher efficiency than do other representative algorithms.In addition,the TO-RANSAC algorithm yields a calculation accuracy considerably higher than that of the traditional RANSAC algorithm.
文摘The effects of source-drain underlaps on the performance of a top gate silicon nanowire on insulator transistor are studied using a three dimensional(3D) self-consistent Poisson-Schrodinger quantum simulation. Voltage-controlled tunnel barrier is the device transport physics. The off current, the on/off current ratio, and the inverse subthreshold slope are improved while the on current is degraded with underlap. The physics behind this behavior is the modulation of a tunnel barrier with underlap. The underlap primarily affects the tunneling component of drain current. About 50% contribution to the gate capacitance comes from the fringing electric fields emanating from the gate metal to the source and drain. The gate capacitance reduces with underlap, which should reduce the intrinsic switching delay and increase the intrinsic cut-off frequency. However, both the on current and the transconductance reduce with underlap, and the consequence is the increase of delay and the reduction of cut-off frequency.
文摘Background:Chukrasia velutina is an enthnomedicinally used plant reported to have significant medicinal values.The present study aimed to explore the pharmacological activities of bark methanol extract using in vitro,in vivo and in silico models.Methods:The study was designed to investigate the pharmacological effects of methanol extract of Chukrasia velutina bark(MECVB)through in vitro,in vivo and in silico assays.Analgesic activity was tested using formalin-i nduced nociception and acetic acid-i nduced writhing assays while the antipyretic effect was tested using yeast-i nduced hyperthermia in mice model.The antioxidant effect was tested using the DPPH and reducing power assay and the cytotoxic screening was tested using the brine shrimp lethality bioassay.In addition,in silico studies were conducted using computer aided methods.Results:In the acetic acid-i nduced writhing assay,the extract showed 28.36%and 56.16%inhibition of writhing for doses of 200 and 400 mg/kg,respectively.Moreover,a dose-dependent formalin-i nduced licking response was observed in both early and late phase.In yeast-i nduced pyrexia,the MECVB exhibited(p<0.05)antipyretic effect.The extract demonstrated an ICvalue of 78.86μg/ml compared with ascorbic acid(IC23.53μg/ml)in the DPPH scavenging assay.The compounds sitosterol,5,7-dimethoxycoumarin and scopoletin were seen be effective in molecular docking scores against COX-I(2OYE),COX-II(6COX)and human peroxiredoxin 5(1HD2).In ADME/T analysis,5,7-dimethoxycoumarin and scopoletin satisfied Lipinski’s rule of five and thus are potential drug candidates.Conclusion:The bark of Chukrasia velutina showed significant analgesic and antipyretic properties and is a potential source of natural anti-oxidative agents.
文摘To cope with the demand and supply of electrical load of an interconnected power system of a country, we need to forecast its demand in advance. In this paper, we use a fuzzy system to forecast electrical load on short-term basis. Here, we consider temperature, humidity, seasons of a year and time segments of a day as the parameters, which govern the demand of electrical load. For each of the parameter, we use several membership functions (MFs) and then apply the Mamdani rule on MFs and the output is determined by using the centroid method. Finally, the surface plot reveals the real scenario of the load demand. The difference between actual load and the output of the fuzzy system is found as +1.65% to -13.76%. The concept of the paper can be applied in interconnected power system of Bangladesh to reduce power loss, especially when generation is higher than the demand.
文摘Power saving is one of the key factors of emerging 4G mobile network as well as in IEEE 802.16e wireless metropolitan area networks (Wireless MAN). An efficient power saving mechanism is the heart for the guarantee of a long operating lifetime for a mobile subscriber station (MS), because MSs are normally driven by rechargeable batteries. It is a vital factor for Base Station (BS) of the same network. One of the most important features of 5G mobile is the extension of battery energy 10 times greater than the present days. In this context, the evaluation of duration of sleep mode of BS or MS based on traffic load of a network is now a new era of research work. In this paper, such analysis has been done based on two statistical models: Poisson’s pdf and Engset pdf. The concept of complete sharing and partitioning of user group of teletraffic engineering is applied to measure the possibility of getting leisure time of BS or MS. Both the traffic models used in the paper are applicable in both limited and unlimited user network, i.e. in micro and fem to cellular network of 4G and 5G.
文摘Internet of Things (IoT) has become a prevalent topic in the world of technology. It helps billion of devices to connect to the internet so that they can exchange data with each other. Nowadays, the IoT can be applied in anything, from cellphones, coffee makers, cars, body sensors to smart surveillance, water distribution, energy management system, and environmental monitoring. However, the rapid growth of IoT has brought new and critical threats to the security and privacy of the users. Due to the millions of insecure IoT devices, an adversary can easily break into an application to make it unstable and steal sensitive user information and data. This paper provides an overview of different kinds of cybersecurity attacks against IoT devices as well as an analysis of IoT architecture. It then discusses the security solutions we can take to protect IoT devices against different kinds of security attacks. The main goal of this research is to enhance the development of IoT research by highlighting the different kinds of security challenges that IoT is facing nowadays, and the existing security solutions we can implement to make IoT devices more secure. In this study, we analyze the security solutions of IoT in three forms: secure authentication, secure communications, and application security to find suitable security solutions for protecting IoT devices.
文摘<span style="font-family:Verdana;">In this study, two Cu</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">based catalysts with and without N doped carbon matrix, named N-Cu/CuO/C and Cu/CuO were synthesized via calcination of melamine-cupper acetate complex and cupper acetate at 500<span style="white-space:nowrap;">°</span>C under an inert atmosphere. The catalysts were characterized by X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and </span><span><span style="font-family:Verdana;">CHNS </span><span><span style="font-family:Verdana;">elemental analyzer</span><i><span style="font-family:Verdana;">.</span></i></span></span><span style="font-family:Verdana;"> The catalytic activity of both catalysts was evaluated</span><span style="font-family:Verdana;"> through the NaBH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> associated reduction of commercial textile dye named reactive black 5 (RB5). The kinetics of the reduction of reactive black 5 was also described by the pseudo-first-order kinetic equation. For the studied reduction, N-Cu/CuO/C exhibited enhanced catalytic activity both in conversion and kinetics (97% conv. in 315 sec) compared to that of by Cu/CuO/C (25% conv. in 1500 sec). Besides, N-Cu/CuO/C also demonstrated good reusability up to four consecutive cycles.</span></span></span></span>
基金Supported by the department of Pharmacy,Spring semester 2011,East West University,Dhaka.Bangladesh(Grant No.:EWU:PHRM:SPRING 2011)
文摘Objective:This study is to investigate the medicinal value of methanolic extiact of the leaves of Musa sapientum var.sylvesteris in Bangladesh.Methods:Several biochemical assays,thin layer chormatogarphy and ultra-violet spectroscopy were used to detect the presence of various types of compounds in this extract.Antioxidant effects were measured by DPPH scavenging assay,total reducing assay and hydrogen peroxide scavenging assay.Receptor binding activities and hydrogen peroxide induced hemolysis assay were performed by hemagglutination assay and hemolysis assay using erythrocytes.Disk diffusion assay was performed to show the antibacterial effect of the extract.Results:Alethanolic extract of the leaves showed antioxidant and antibacterial activity in ritro.The extract showed hemaglutination inhibition activities and hydrogen peroxide induced hemolysis inhibition activity of human red blood cells.Conclusion:Musa sapientum var.sylvesteris can be an useful medicinal plant.
文摘This paper investigates the effect of inflow, outflow and shock waves in a single lane highway traffic flow problem. A constant source term has been introduced to demonstrate the inflow and outflow. The classical Lighthill Whitham and Richards (LWR) model combined with the Greenshields model is used to obtain analytical and numerical solutions. The model is treated as an IBVP and numerical solutions are presented using Lax Friedrichs scheme. Godunov method is also used to present shock wave analysis. The numerical procedures adopted in this investigation yield results which are very much consistent with real life scenario in terms of traffic density and velocity.
文摘Atomistic quantum simulation is performed to compare the performance of zero-Schottky-barrier and doped source-drain contacts carbon nanotube field effect transistors(CNTFETs) with strain applied. The doped source-drain contact CNTFETs outperform the Schottky contact devices with and without strain applied. The off-state current in both types of contact is similar with and without strain applied. This is because both types of contact offer very similar potential barrier in off-state. However, the on-state current in doped contact devices is much higher due to better modulation of on-state potential profile, and its variation with strain is sensitive to the device contact type. The on/off current ratio and the inverse subthreshold slope are better with doped source-drain contact, and their variations with strain are relatively less sensitive to the device contact type. The channel transconductance and device switching performance are much better with doped source-drain contact, and their variations with strain are sensitive to device contact type.
基金supported by the New Energy and Industrial Technology Development Organization of Japan(No.A0006)
文摘An innovative in-flight glass melting technology with thermal plasmas was developed for the purpose of energy conservation and environment protection. In this study, modelling and experiments of argon-oxygen induction thermal plasmas were conducted to investigate the melting behaviour of granulated soda-lime glass powders injected into the plasma. A two-dimensional local thermodynamic equilibrium （LTE） model was performed to simulate the heat and momentum transfer between plasma and particle. Results showed that the particle temperature was strongly affected by the flow rate of carrier gas and the particle size of raw material. A higher flow rate of carrier gas led to lower particle temperature and less energy transferred to particles which resulted in lower vitrification. The incomplete melting of large particles was attributed to the lower central temperature of the particle caused by a larger heat capacity. The numerical analysis explained well the experimental results, which can provide valuable practical guidelines for the process control in the melting process for the glass industry.
文摘In this paper, an intuitive comparison of the computational performance of orthogonal frequency division multiplexing (OFDM) system has been made in terms of complex calculations required using different Fourier transform techniques. The different transform techniques are introduced such as discrete Fourier transform (DFT) and various types of fast Fourier transform (FFT) as 2-radix FFT, 4-radix FFT etc. and the very recent very fast Fourier transform (VFFT). With intuitive mathematical analysis, it has been shown that with the reduced complexity that VFFT can offer, OFDM performance can be greatly improved in terms of calculations needed.
文摘Use of different solvent systems for extraction of plant materials may cause variation in their bioactivities. The present study was conducted to evaluate the presence of different phytoconstituents and to compare in vitro bioactivities of petroleum ether, dichloromethane (DCM) and methanol extracts of Bombax ceiba (B. ceiba) roots available in Bangladesh. Preliminary phytochemical screening was conducted using specific standard procedure. Antioxidant activity of the extracts was evaluated using DPPH radical scavenging assay. Determination of total phenolic and flavonoid content was also carried out. Antibacterial and cytotoxic activities were investigated using disc diffusion method and brine shrimp lethality bioassay, respectively. All the experiments were carried out from February 2016 to September 2016. Phytochemical evaluation revealed the presence of alkaloids, terpenoids, carbohydrates, tannins, flavonoids, saponins and steroids. The methanol extract showed the highest DPPH radical scavenging activity and had the highest phenolic (187.42 ± 3.77 mg/g, GAE) and flavonoid content (74.67 ± 4 mg/g, QE) followed by the DCM and petroleum ether extracts. The extracts showed positive correlation between DPPH radical scavenging activity with the phenolic and flavonoid content. All the extracts showed mild to moderate in vitro antibacterial activity with zone of inhibition ranging from 7 mm to 13 mm. In brine shrimp lethality bioassay, the observed LC50 values for petroleum ether, DCM and methanol extracts were 70.72 μg/ml, 37.72 μg/ml and 22.58 μg/ml, respectively which revealed strong cytotoxic potential of the extracts compared to the positive control. The results indicated that B. ceiba roots could be a very potent source of natural radical scavenger and cytotoxic agent.
文摘To enhance link capacity of a wireless link one or more repeater is used between the sender and the receiver. Recent literature deals with multiple parallel links to enhance throughput instead of conventional single path. In case of a multidirectional and multi-hop wireless network, the selection of link of maximum signal to noise ratio (SNR) does not guarantee the maximum throughput. In this paper, we use augmenting path of Ford-Fulkerson algorithm in detection of maximum flow from sender to receiver. To reduce the process time at the sending node, minimum-cut theorem is used to determine maximum flow like power flow of previous work. Using the maximum flow algorithm, we obtain the capacity of multi-hop wireless link higher than the conventional theorem. The concept of the paper is applicable in MANET (Mobile Ad-hoc Network), WSN (Wireless Sensor Network) and CRN (Cognitive Radio Network).
文摘The nonlinear propagation of dust-acoustic (DA) shock waves in three-component unmagnetized dusty plasma consisting of nonextensive electrons, Maxwellian ions and arbitrarily charged mobile dust grain has been investigated. It is found that the presence of q-nonextensive electrons and ions can change the nonlinear behavior of shock wave. The standard reductive perturbation method is employed to study the basic features (phase speed, amplitude and width) of DA shock waves (DASWs) which are significantly modified by the presence of Maxwellian ions and nonextensive electrons. The present investigation can be very effective for understanding the nonlinear characteristics of the DASWs in space and laboratory dusty plasmas.
文摘Energy efficiency plays vital roles in wireless communication system due to the “energy limited battery service” of a mobile station (MS). To ensure longer battery life in WiMAX, a new protocol has been introduced in its IEEE802.16m version. This new sleep mode has extended listening window and adjustable sleep cycle length. In this paper, we analyze the probability of attaining at three states: serving state, state of timer inactivity and silent state in a simplified statistical model using traffic parameters of arrival rate, pdf (probability density function) of interarrival time and its threshold value. Finally we developed a new state transition chain of the above three states of a MS of IEEE802.16m and solved the chain in closed form.
