Preparation and performance evaluation of poly (ether-imide) incorporated polysulfone hemodialysis membranes

Biocompatible Polysulfone (PSf) hemodialysis membranes were prepared by phase inversion technique using poly (ether-imide) (PEI) as the modification agent and Polyethylene glycol (PEG-200) as the pore former. The effect of PSf/PEI blend ratio on the morphology, hydrophilicity, water content, porosity, glass transition temperature, mechanical strength, biocompatibility and permeation rate of the prepared membranes were studied and were found to be improved significantly by the incorporation of PEI in the dope solution. The scanning electron microscopy (SEM) studies revealed that, incorporation of PEI resulted in the formation of spongy sub-layer and increased the connectivity of pores between sub-layer and bottom layer. The water content and permeation rate of the membranes of PSf/PEI blend membranes were increased considerably indicating the enhancement of hydrophilicity and it was supported by lower contact angle values of the blend membranes. The existence of single well defined Tg over entire composition established the compatibility between the components in blend membranes. The biocompatibility of membranes was investigated through protein adsorption, platelet adhesion and thrombus formation on the membrane surface. Anticoagulant activity of PSf/PEI blend membranes was evaluated by measuring the activated partial thrombin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen time (FT). The results revealed that antithrombogenicity of PSf/PEI blend membranes was increased significantly. The efficiency of these membranes in removal of urea, creatinine and vitamin B₁₂ were studied and found to be improved for blend membranes. Thus, it is worth mentioning to note that, the biocompatible PSf/PEI blend membranes prepared in this study would offer immense potential in hemodialysis.     

Molecular Epidemiological Study of Pyrazinamide-Resistance in Clinical Isolates of Mycobacterium tuberculosis from South India

Pyrazinamide (PZA) has been in use for almost 50 years as a first-line drug for short-course chemotherapy against Mycobacterium tuberculosis. In this study, PCR mediated automated DNA sequencing is used to check the prevalence of PZA resistance among treatment failure cases of pulmonary tuberculosis. Out of 50 clinical isolates examined, 39 had mutations in the pncA gene that encodes Pyrazinamidase, an enzyme required to activate PZA. Of these, 31 (79.5%) were localized to three regions of pncA. We found two isolates with hitherto unreported mutation at amino acid 26 (Ala→Gly) of pncA.     

Evaporation rate and engine performance analysis of coated diesel engine using Raphanus sativus biodiesel and its diesel blends

An experimental investigation to measure the evaporation rates, PSZ-coated engine performance and emissions of radish biodiesel (Methyl Ester of radish oil) and its blends in different volumetric proportions with diesel is presented. The thermo-physical properties of all the fuel blends have been measured and presented. Evaporation rates of neat radish biodiesel, neat diesel and their bends have been measured under slow convective environment of air velocity of 0.2?m/s with a constant temperature of 200°C. Evaporation constants have been determined by using the droplet regression rate data. The neat fuels and fuel blends have been utilised in a test engine with different load conditions to evaluate the performance and emission characteristics of the fuels. From the observed evaporation, performance and emissions characteristics, it can be suggested that a blend of B25–B75 could be optimally used in coated diesel engine settings without any modifications on it.     

In-situ synthesis of silica aerogel in polyethylene terephthalate fibre nonwovens and their composite properties on acoustical absorption behavior

In this research work we focus on engineering the silica aerogel/polyethylene terephthalate (PET) fibre nonwoven fabric composites with various silica content during in-situ synthesis of silica aerogels in the nonwovens and their composite properties on sound absorption. The silica content was varied by varying the molar ratio of methanol (MeOH)/tetraethyl orthosilicate (TEOS) from 110 to 28. The gelation of silica alcogel took place inside the fabric followed by silylation and atmospheric pressure drying. The aerogel/PET nonwoven composites were characterized by FTIR, TGA and contact angle to explain the aerogel content and its behavior. Moreover, the physical properties such as thickness, bulk density, specific airflow resistance, and mean flow pore size have been investigated. The two microphone transfer function method was used to test the sound absorption coefficient (SAC) of aerogel composites at 1/3rd octave frequencies of 50–6300 Hz. The aerogel/PET nonwoven composites have exhibited higher SAC than the untreated or control PET nonwoven for the entire frequency range. The suitable solvent molar ratio of 55 has been recommended for synthesis of silica aerogels by considering not only the silica content to have high sound absorption but also based on hydrophobic characteristics of aerogel/PET nonwoven composites.     

Association Rule Mining Frequent-Pattern-Based Intrusion Detection in Network

In the network security system, intrusion detection plays a significant role. The network security system detects the malicious actions in the network and also conforms the availability, integrity and confidentiality of data information resources. Intrusion identification system can easily detect the false positive alerts. If large number of false positive alerts are created then it makes intrusion detection system as difficult to differentiate the false positive alerts from genuine attacks. Many research works have been done. The issues in the existing algorithms are more memory space and need more time to execute the transactions of records. This paper proposes a novel framework of network security Intrusion Detection System (IDS) using Modified Frequent Pattern (MFP-Tree) via K-means algorithm. The accuracy rate of Modified Frequent Pattern Tree (MFPT)-K means method in finding the various attacks are Normal 94.89%, for DoS based attack 98.34%, for User to Root (U2R) attacks got 96.73%, Remote to Local (R2L) got 95.89% and Probe attack got 92.67% and is optimal when it is compared with other existing algorithms of K-Means and APRIORI.     

Uniplanar ACS fed multiband high‐gain antenna with extended rectangular strips for portable system applications

In this article, a compact uniplanar asymmetric coplanar strip (ACS)‐fed multiband antenna with extended rectangular strips is proposed for portable system applications. It is composed of a modified mouse and rectangular‐shaped radiating strip for generating three resonance frequency bands simultaneously. The proposed antenna has a compact size of 16 × 26 × 1.6 mm³. Antenna has |S₁₁| ≤ ?10 dB at three independent controlled bandwidths from 2.2 to 2.4 GHz, 3.5 to 3.7 GHz, and 4.85 to 6.85 GHz. The proposed ACS‐fed antenna is suitable for LTE 2300, WiBro 2300 GHz, 5.2/5.8‐GHz WLAN, 3.5/5.5‐GHz WiMAX, 4.9‐GHz US public safety band, and 5.9‐GHz WAVE applications. The antenna has omnidirectional radiation characteristics in the desired frequency bands in both E‐plane and H‐plane. It has better gain value performance compared with other antenna designs discussed in the literature.     

Dishing and nitride erosion of STI-CMP for different integration schemes

In this paper, we investigate the effects of integration schemes on the STI-CMP performance of two polishers, as well as the influence of consumables and process parameters. The experiment was based on both the blanket-oxide wafers and the patterned wafers processed using 0.18 μm technology. The polishing capability was evaluated, based on the results collected using metrology tools such as Opti-probe, Tencor profiler; atomic force microscope (AFM), and x-ray-scanning electron microscopy (X-SEM) analysis.     

Surfactant‐mediated synthesis of polyhydroxybutyrate (PHB) nanoparticles for sustained drug delivery

In this study, polyhydroxybutyrate (PHB) nanoparticles were synthesised following nanoprecipitation method having different solvents and surfactant (Tween 80) concentrations. In this study, PHB nanoparticles were encapsulated with curcumin and subjected for sustained curcumin delivery. Both the curcumin loaded and unloaded PHB nanoparticles were characterised using FTIR, SEM, and AFM. Sizes of the particles were found to be between 60 and 300 nm. The drug encapsulation efficiency and in vitro drug release of the nanoparticles were analysed. Antibacterial activity and anticancer activity were also evaluated. The LC₅₀ values of most of the nanoparticles were found to be between 10 and 20 µg/100 µl, anticancer activity of curcumin loaded PHB nanoparticles were further confirmed by AO/PI staining and mitochondrial depolarisation assay.Inspec keywords: encapsulation, cancer, scanning electron microscopy, nanoparticles, surfactants, drugs, nanofabrication, antibacterial activity, biomedical materials, drug delivery systems, polymers, nanomedicine, Fourier transform infrared spectra, precipitation (physical chemistry), atomic force microscopy, particle sizeOther keywords: surfactant‐mediated synthesis, polyhydroxybutyrate nanoparticles, sustained drug delivery, surfactant concentrations, PHB nanoparticles, sustained curcumin delivery, drug encapsulation efficiency, anticancer activity, in vitro drug release, nanoprecipitation method, Tween 80, FTIR spectra, SEM, AFM, particle sizes, antibacterial activity, AO‐PI staining, mitochondrial depolarisation assay