Synthesis,characterization, and blood compatibility of copolymers of polyamidoamines and n‐vinylpyrrolidone

Two new polyamidoamines derived from piperazine (Pip)/cyclohexylamine (CHA) and N,N′‐methylene bisacrylamide (MBA) were synthesized and subsequently copolymerized with N‐vinylpyrrolidone (NVP) under suitable reaction conditions to yield the respective copolymers (Pip–MBA–NVP and CHA–MBA–NVP). The synthesized materials were characterized by spectroscopic techniques. The material surface characteristics were checked by contact angle measurement, and the data established the relative hydrophilic characteristics of the synthesized copolymers with respect to the control poly(N‐vinylpyrrolidone). A thrombus‐formation study indicated less (<1.2 mg) clot formation on the heparinized material surfaces within a 30‐min contact time with the acid citrate dextrose human blood. The percentage of hemolysis of the blood by the materials was also less than 5%. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4068–4074, 2003     

Lessons from the Far End: Caterpillar FRASS-Induced Defenses in Maize,Rice, Cabbage,and Tomato

Plant defenses to insect herbivores have been studied in response to several insect behaviors on plants such as feeding, crawling, and oviposition. However, we have only scratched the surface about how insect feces induce plant defenses. In this study, we measured frass-induced plant defenses in maize, rice, cabbage, and tomato by chewing herbivores such as European corn borer (ECB), fall armyworm (FAW), cabbage looper (CL), and tomato fruit worm (TFW). We observed that caterpillar frass induced plant defenses are specific to each host-herbivore system, and they may induce herbivore or pathogen defense responses in the host plant depending on the composition of the frass deposited on the plant, the plant organ where it is deposited, and the species of insect. This study adds another layer of complexity in plant-insect interactions where analysis of frass-induced defenses has been neglected even in host-herbivore systems where naturally frass accumulates in enclosed feeding sites over extended periods of time.     

Effect of yttria on sintering and microstructural behavior of reaction sintered mullite based on bauxite,fly ash and precipitated silica

The present investigation on the effect of Y₂O₃ towards the sintering behavior of mullite compacts revealed that rapid mullitization occurred through nucleation and normal grain growth due to the formation of yttrious silicate glassy phase. The intergranular voids were progressively eliminated by yttrious silicate glass leading to significant decrease in porosity with the corresponding remarkable rise in mechanical strength of sintered compacts. The uniform dispersion of microfine corundum grains into the mullite matrix with 1.5% Y₂O₃ content was noticed during sintering at 1550?°C and above.     

Octadecyl‐silica—PVDF membrane of superior MD desalination performance

Despite its widespread industrial and residential uses for production of potable water, the reverse osmosis (RO) desalination process has some drawbacks by discharging harmful concentrated saline water as reject stream. A hydrophobic porous membrane can treat such environmentally unfriendly RO reject stream via Membrane Distillation (MD) process. Here, we describe preparation of superior polyvinylidenefluoride (PVDF) membrane modified with superhydrophobic silica nanoparticles for desalination application. Superhydrophobicity (contact angle of 151°) of silica nanoparticles of 7 nm sizes was achieved by reaction of the silica particles with octadecyltrichlorosilane in toluene to form ? Si? O? Si? links with C18 alkyl chain. A homogeneous polymer dope mixture containing a desired amount of modified silica colloids suspended in toluene was used for the membrane preparation. The PVDF membrane with optimal silica content exhibited excellent flux with >99% salt rejection efficiency when used for MD at room temperature from the saline water feed of 3.5 wt % NaCl. The prepared hydrophobic PVDF membrane has the potential for MD application in treating the RO reject stream and other aqueous industrial effluents. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46043.     

不同熔化条件对Na2O·4TeO2玻璃性能的影响

探索了不同熔化条件对 Na2 O· 4Te O2 玻璃性能的影响 ,确定了 Na2 O- Te O2 系统玻璃的合理的熔化条件。通过热分析和红外分析等手段 ,对由不同原料在不同熔化条件下所得到的玻璃进行了分析 ,发现熔化条件不同时 ,由不同原料所得玻璃的性能也有很大差别。当熔化温度较低、熔化时间较短时 ,玻璃中存在未分解完全的来自原料的原子基团。由不同原料所得的玻璃的 DSC曲线和抗析晶能力差别很大。随着熔化温度的升高和熔化时间的延长 ,由不同原料熔化所得玻璃的性能趋于一致。在 80 0℃下熔化 1 h是亚碲酸钠玻璃较合适的熔化条件     

Statistical analysis of mammographic features and its classification using support vector machine

This study aims at designing a support vector machine (SVM)-based classifier for breast cancer detection with higher degree of accuracy. It introduces a best possible training scheme of the features extracted from the mammogram, by first selecting the kernel function and then choosing a suitable training-test partition. Prior to classification, detailed statistical analysis viz., test of significance, density estimation have been performed for identifying discriminating power of the features in between malignant and benign classes. A comparative study has been performed in respect to diagnostic measures viz., confusion matrix, sensitivity and specificity. Here we have considered two data sets from UCI machine learning database having nine and ten dimensional feature spaces for classification. Furthermore, the overall classification accuracy obtained by using the proposed classification strategy is 99.385% for dataset-I and 93.726% for dataset-II, respectively.     

Direct Analysis of hCGβcf Glycosylation in Normal and Aberrant Pregnancy by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

The analysis of human chorionic gonadotropin (hCG) in clinical chemistry laboratories by specific immunoassay is well established. However, changes in glycosylation are not as easily assayed and yet alterations in hCG glycosylation is associated with abnormal pregnancy. hCGβ-core fragment (hCGβcf) was isolated from the urine of women, pregnant with normal, molar and hyperemesis gravidarum pregnancies. Each sample was subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) analysis following dithiothreitol (DTT) reduction and fingerprint spectra of peptide hCGβ 6–40 were analyzed. Samples were variably glycosylated, where most structures were small, core and largely mono-antennary. Larger single bi-antennary and mixtures of larger mono-antennary and bi-antennary moieties were also observed in some samples. Larger glycoforms were more abundant in the abnormal pregnancies and tri-antennary carbohydrate moieties were only observed in the samples from molar and hyperemesis gravidarum pregnancies. Given that such spectral profiling differences may be characteristic, development of small sample preparation for mass spectral analysis of hCG may lead to a simpler and faster approach to glycostructural analysis and potentially a novel clinical diagnostic test.     

Evaporation of clearcoat solvents from a rotary bell atomizer and its relationship with bell speed,flow rate,and electrostatic potential

The relations between evaporation of clearcoat solvents and various operating parameters of the spray from a rotary bell atomizer were measured using a particle dynamic anemometer (PDA). The robot arm holding the spray applicator was moved relative to the PDA so that the volume flux at different parts of the spray could be measured. The difference in total flux between two planes, perpendicular to the spray axis, was considered to be equal to the evaporation. Evaporation was found to increase with increasing bell speed. Evaporation also increased with increasing coatings flow rate from 100 to 200 cm³/s flow rate, but not for a further increase to 300 cm³/s. Higher electrostatic potential, bell speed, and lower flow rate decrease the mean particle diameter. Particle mean velocity increases with increasing bell speed and flow rate. Coatings flow rate, bell speed, electrostatic potential, and the interaction between flow rate and bell speed were significant factors affecting evaporation rate. Of the former three, coatings flow rate was the most influential.     

Effect of nanofillers characteristics and their selective localization on morphology development and rheological properties of melt-processed polylactide/poly(butylene adipate-co-terephthalate) blend composites

This article reports the effects of the characteristics and selective localization of nanofillers on the morphology development and rheological properties of melt-processed polylactide/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blend composites. Four types of nanofillers (1 wt%) are used: nanoclay (Cloisite30B [C30B]), carbon nanotubes (CNTs), nanosilica, and graphene oxide (GO). Transmission electron microscopy studies reveal that C30B is localized mainly at the PLA/PBAT interface, whereas silica, GO, and CNT are localized in PBAT droplets, although some CNTs also appear toward the interface inside the PBAT. Despite their selective localization inside the PBAT, CNTs are found to be the most effective particles for droplet size reduction, whereas silica nanoparticles are ineffective. The CNT bundles recoil during melt blending, and eventually, their breakage facilitates droplet breakup. The effects of nanofiller localization and annealing under dynamic shear on the blend morphologies are also explored through rheological analysis. The results show an anomalous relationship with the morphologies of the composites. It is also found that both coalescence and thermal degradation are involved in the annealing process of the blends. Interestingly, the CNT-filled composites may have been transformed into co-continuous-like structures during annealing, unlike the other blends studied here.     

Morphological characteristics and thermal,rheological, and mechanical properties of cellulose nanocrystals-containing biodegradable poly(lactic acid)/poly(ε-caprolactone) blend composites

This work investigates the effect of cellulose nanocrystal (CN) loading on the properties of polylactide / poly(ε-caprolactone) (PLA/PCL) (70/30) blend processed in a twin-screw extruder as a potential material that can be utilized in various applications where biodegradation is highly desired. The morphological analysis revealed a reduction in droplet size of dispersed PCL phase upon addition of CN at low concentrations (1 and 2 wt %) with maximum reduction at 2 wt % which led to maximum improvement in mechanical properties. The reinforcing effect of CN in increasing the DMA storage modulus of the prepared systems was noticed when CN concentration was increased. Further, CN enhanced the crystallization of PCL, whereas the cold crystallization of PLA remained the same with CN addition. Both melt strength and viscosity of PLA improved with the incorporation of PCL and CN. In general, a green composite material with improved properties was successfully prepared using an environmentally friendly filler material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48665.