Because of its excellent optical performance and electrical properties, TiO 2 has a wide range of applications in many fields. It is often considered to be physiologically inert to humans. However, some recent studies have reported that nano-sized TiO 2 may generate potential harm to the environment and humans. In this paper the in vivo acute toxicity of nano-sized TiO 2 particles to adult mice was investigated. Mice were injected with different dosages of nano-sized TiO 2 (0, 324, 648, 972, 1296, 1944 or 2592 mg kg -1 ). The effects of particles on serum biochemical levels were evaluated at various time points (24 h, 48 h, 7 days and 14 days). Tissues (spleen, heart, lung, kidney and liver) were collected for titanium content analysis and histopathological examination. Treated mice showed signs of acute toxicity such as passive behavior, loss of appetite, tremor and lethargy. Slightly elevated levels of the enzymes alanine aminotransferase and aspartate aminotransferase were found from the biochemical tests of serum whereas blood urea nitrogen was not significantly affected (P < 0.05). The accumulation of TiO 2 was highest in spleen (P < 0.05). TiO 2 was also deposited in liver, kidney and lung. Histopathological examinations showed that some TiO 2 particles had entered the spleen and caused the lesion of spleen. Thrombosis was found in the pulmonary vascular system, which could be induced by the blocking of blood vessels with TiO 2 particles. Moreover, hepatocellular necrosis and apoptosis, hepatic fibrosis, renal glomerulus swelling and interstitial pneumonia associated with alveolar septal thickening were also observed in high-dose groups.

We have used the finite-difference time-domain (FDTD) method to calculate induced current densities in a 1.31-cm (nominal 1/2 in) resolution anatomically based model of the human body for exposure to purely electric, purely magnetic, and combined electric and magnetic fields at 60 Hz. This model based on anatomic sectional diagrams consists of 45,024 cubic cells of dimension 1.31 cm for which the volume-averaged tissue properties are prescribed. It is recognized that the conductivities of several tissues (skeletal muscle, bone, etc.) are highly anisotropic for power-line frequencies. This has, however, been neglected in the first instance and will be included in future calculations. Because of the quasi-static nature of coupling at the power-line frequencies, a higher quasi-static frequency f' may be used for irradiation of the model, and the internal fields E' thus calculated can be scaled back to the frequency of interest, e.g., 60 Hz. Since in the FDTD method one needs to calculate in the time domain until convergence is obtained (typically 3-4 time periods), this frequency scaling to 5-10 MHz for f' reduces the needed number of iterations by over 5 orders of magnitude. The data calculated for the induced current and its variation as a function of height are in excellent agreement with the data published in the literature. The average current densities calculated for the various sections of the body for the magnetic field component (H) are considerably smaller (by a factor of 20-50) than those due to the vertically polarized electric field component when the ratio E/H is 377 ohms. We have also used the previously described impedance method to calculate the induced current densities for the anatomically based model of the human body for the various orientations of the time-varying magnetic fields, namely from side to side, front to back, or from top to bottom of the model, respectively.

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High-purity anatase TiO2nanoparticles were prepared using an improved sol-hydrothermal method. The as-prepared sample was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and UV-vis diffuse reflectance spectra. TEM results showed that the average particle size of all TiO2particles was calculated to be (10±1) nm. The XRD analysis indicated that the present sample was fully crystallized and appeared to be highly phase-pure anatase. The BET analysis showed that the as-prepared sample had a very large specific surface area of 186.25 m2/g. The photocatalytic performance of TiO2nanoparticles was evaluated by photocatalytic degradation of X-3B and X-BR solutions. The degradation results revealed that the as-prepared TiO2showed slightly higher photocatalytic activities than P25. Whereas, the as-synthesized TiO2can settle down and be separated easily after the photocatalytic reaction finishes.

In this study, thin-film composite nanofiltration (NF) hollow-fiber membranes were used to remove heavy metals from actual electroplating wastewater. The effects of the operating pressure, feed temperature, and feed pH on the membrane performance for the treatment of electroplating wastewater were investigated. The rejection rates for chromium, copper, and nickel ions reached 95.76%, 95.33%, and 94.99%, respectively, at 0.4 MPa. With a rise in the feed temperature, the permeate flux increased while the rejection rates of heavy metals did not significantly change. It was evident that the feed pH greatly affected the permeate flux and heavy-metal rejection as well. In addition, all of the rejection rates of heavy metals by the membrane were over 94.8% throughout the electroplating wastewater concentration process. Also, the NF hollow-fiber membrane showed good stability in electroplating wastewater with a pH value of 2.31.

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Alfalfa (Medicago sativa L.) is one of the most important and widely cultivated forage crops. It is commonly used as a vegetable and medicinal herb because of its excellent nutritional quality and significant economic value. Based on Illumina, Nanopore and Hi-C data, we assembled a chromosome-scale assembly of Medicago sativa spp. caerulea (voucher PI464715), the direct diploid progenitor of autotetraploid alfalfa. The assembled genome comprises 793.2 Mb of genomic sequence and 47,202 annotated protein-coding genes. The contig N50 length is 3.86 Mb. This genome is almost twofold larger and contains more annotated protein-coding genes than that of its close relative, Medicago truncatula (420 Mb and 44,623 genes). The more expanded gene families compared with those in M. truncatula and the expansion of repetitive elements rather than whole-genome duplication (i.e., the two species share the ancestral Papilionoideae whole-genome duplication event) may have contributed to the large genome size of M. sativa spp. caerulea. Comparative and evolutionary analyses revealed that M. sativa spp. caerulea diverged from M. truncatula ~5.2 million years ago, and the chromosomal fissions and fusions detected between the two genomes occurred during the divergence of the two species. In addition, we identified 489 resistance (R) genes and 82 and 85 candidate genes involved in the lignin and cellulose biosynthesis pathways, respectively. The near-complete and accurate diploid alfalfa reference genome obtained herein serves as an important complement to the recently assembled autotetraploid alfalfa genome and will provide valuable genomic resources for investigating the genomic architecture of autotetraploid alfalfa as well as for improving breeding strategies in alfalfa.