Recent advances of cerium compounds in functional coatings:Principle,strategies and applications

Cerium(Ce) compounds have attracted considerable attention as key components in functional coatings due to their many outstanding properties.This work provides a comprehensive review of recent advances in the application of Ce in functional coatings.The role of Ce in the improvement of functional properties such as corrosion-resistance,self-healing,superhydrophobicity,wear-resistance,and UV shielding is reviewed from the perspective of functional mechanism and applied research.Furthermore,the strategies,processes,practical problems,and current challenges in the research of functional coatings containing Ce are summarized and discussed.The objective is to highlight the great potential of Ce in functional coatings,and to explore new applications of Ce in the development of novel coatings.Thus,this work aims to enhance the application value of Ce,solving the problem of unbalanced application of rare-earth elements.     

Comparison of extraction methods and detection systems in the gas chromatographic analysis of volatile carbonyl compounds

High-resolution gas chromatography (HRGC) with electron-capture detection (ECD), nitrogen-phosphorus detection (NPD), flame ionization detection (FID) or with mass spectrometry-selected ion monitoring (MS-SIM) was used in the analysis of volatile carbonyl compounds. Eighteen carbonyl compounds that are typically produced during lipid peroxidation were derivatized quantitatively with pentafluorophenylhydrazine (PFPH) at room temperature, to afford their corresponding water-insoluble hydrazones. These derivatives were extracted into non-polar phases by means of either liquid-liquid extraction (LLE) (hexane) or solid-phase extraction (SPE) on 3 ml C18 octadecyl-bonded phase cartridges. Detection limits of 10(-14) and 10(-12) mol/ml per aldehyde were achieved with the ECD and MS-SIM systems, respectively. The effects of extraction conditions on sensitivity and recovery were determined by performing parallel HRGC-ECD and HRGC-MS-SIM analyses of pentafluorophenylhydrazones of the eighteen compounds under study. Recoveries of 51.4-78.9 +/- 1.2-4.5 and 80.9-98.3 +/- 1.0-3.5% were obtained with LLE and SPE, respectively. The method was applied to the analysis of the volatile carbonyl compounds in various heated vegetable oils (corn, palm or sunflower) and to the analysis of volatile aldehydes in human urine.     

Determination of salicin and related compounds in botanical dietary supplements by liquid chromatography with fluorescence detection

The centromeric dodeca-satellite of Drosophila forms unusual DNA structures in which its purine-rich strand (GTACGGGACCGA)n folds into very stable intramolecular hairpins. These intramolecular hairpins contain groups of tandem 5'-GA:GA-3' mismatches that, as judged by gel electrophoresis analysis and UV-melting studies, have a determinant contribution to their stability. Duplexes of the dodeca-satellite purine-rich strand, carrying tandem 5'-GA:GA-3' mismatches, are as stable as equivalent fully Watson-Crick duplexes containing tandem 5'-TA:TA-3' Watson-Crick pairs in place of the non-Watson-Crick G.A pairs. On the other hand, duplexes carrying any of the other three possible tandem combinations of purine.purine mismatches, including G.A pairs on the opposite orientation 5'-AG:AG-3', are very unstable. The high stability of the dodeca-satellite hairplus suggests that the tandem G.A pairs are on the sheared configuration although they are found within the less favourable 5'-G-(G-A)-C-3' sequence context. Other centromeres DNA sequences, including the AAGAG satellite of Drosophila and the mammalian CENP-B box sequence, have the potential of forming intramolecular hairpins stabilised by similar purine.purine interactions.     

Analytical performance of accelerator mass spectrometry and liquid scintillation counting for detection of 14C-labeled atrazine metabolites in human urine

Accelerator mass spectrometry (AMS) has been applied to the detection of 14C-labeled urinary metabolites of the triazine herbicide, atrazine, and the analytical performance of AMS has been directly compared to that of liquid scintillation counting (LSC). Ten human subjects were given a dermal dose of 14C-labeled atrazine over 24 h, and urine from the subjects was collected over a 7-day period. Concentrations of 14C in the samples have been determined by AMS and LSC and range from 1.8 fmol/mL to 4.3 pmol/mL. Data from these two methods have a correlation coefficient of 0.998 for a linear plot of the entire sample set. Accelerator mass spectrometry provides superior concentration (2.2 vs 27 fmol/mL) and mass (5.5 vs 54,000 amol) detection limits relative to those of LSC for these samples. The precision of the data provided by AMS for low-level samples is 1.7%, and the day-to-day reproducibility of the AMS measurements is 3.9%. Factors limiting AMS detection limits for these samples and ways in which these can be improved are examined.     

Modeling population heterogeneity in appearance- and performance-enhancing drug (APED) use: Applications of mixture modeling in 400 regular APED users.

Appearance- and performance-enhancing drugs (APEDs) constitute a wide range of substances, including anabolic-androgenic steroids, nonsteroidal anabolics, and licit and illicit ergo/thermogenics. A great deal of heterogeneity exists in APED use patterns among weight-lifting men, and, consequently, little is known about how these patterns are related to side effect profiles or risk potential. In the current study, a sample of 400 adult men who were regular APED users completed an interactive Web-based instrument detailing information about APED use, side effects, and related indicators of risk. To explore the heterogeneity of APED use patterns, the authors subjected data on use patterns to (a) latent class analysis (LCA), (b) latent trait analysis (LTA), and (c) factor mixture analysis to determine the best model of APED use. Results indicated that a 4-class factor mixture model provided a better fit than LCA and LTA models. The authors also found that severity and latent class were uniquely associated with negative outcomes. Each of the 4 classes was associated with unique side effects, motivations, and participant use patterns. Implications for identifying pathological forms of APED use are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recent advances in chemoprevention of cancer

Chemoprevention is the use of pharmacologic or natural agents that inhibit the development of invasive cancer either by blocking the DNA damage that initiates carcinogenesis or by arresting or reversing the progression of premalignant cells in which such damage has already occurred. Recent advances in our understanding of the mechanisms of carcinogenesis have led to the synthesis of new drugs that can inhibit tumor development in experimental animals by selective action on specific molecular targets, such as the estrogen, androgen, and retinoid receptors or inducible cyclooxygenase. Several of these agents (including tamoxifen, 13-cis-retinoic acid, retinyl palmitate, and an acyclic retinoid) are clinically effective in preventing the development of cancer, particularly in patients who are at high risk for developing second primary tumors after surgical removal of the initial tumor.     

稀散金属铼的化学分析进展

铼属于贵重稀散金属,对分析要求较高。近年来,国内外铼的分析方法发展较快,铼矿样的处理方法、铼的分离富集方法及铼的测定方法都有不同程度的进展。根据资料,总结了金属铼的化学分析进展状况。     

Recent advances in phage display

The selection of peptides and proteins from libraries expressed on the surface of filamentous phage is becoming an important tool in biotechnology. Recent developments have shown that peptides can be selected to bind receptors and antibodies, while semisynthetic antibodies can be selected to bind almost any target. Phage display has allowed the routine isolation of therapeutically interesting human antibodies. Phage are also being utilized to examine the specificities of natural enzymes as well as to evolve novel enzymes de novo.     

Recent advances in insect neuropeptides

1. The number of insect neuropeptides identified chemically grows rapidly and most important neuropeptides have already been characterized. After multi-year efforts Bombyx diapause hormone has recently been isolated and sequenced. 2. New approaches to search for new insect neuropeptides have been carried out by two groups of workers, which have succeeded in identifying several unique peptides. 3. cDNAs for more than 10 insect neuropeptides have been cloned and sequenced. It was found that two functionally distinct neuropeptides, Bombyx diapause hormone and pheromone biosynthesis activating neuropeptide, are encoded in a single gene.     

Recent advances in cancer therapy

The treatment of cancer has developed substantially from its conception in the first years of the 20th century. Since the introduction of alkylating agents during second World War, the oncology specialty has markedly grown. In the recent years, new drugs have been approved for the treatment of cancer. Such examples include the taxanes (Docetaxel and Paclitaxel), Vinorelbine, Irinotecan, Topotecan, Gemcitabine and Gliadel. We will discuss these new chemotherapuetic agents, their pharmacology, indications, toxicity and appropriate dosing. There is no doubt that further clinical research is needed to determine the optimal use of these agents.     

New advances in contact allergology

In October 1996, dermatologists commemorated the centenary of the Patch test that Jadassohn had developed in 1896 at Breslau. A great amount of scientific information came to light in the following years due to progress in immunology applied to dermatology. To consider the most important recent advances in the field of contact allergic dermatitis, it is necessary to recognise the role of adhesion molecules specific for antigen presenting dendritic cells, also keratinocytes as antigen presenting cells, the importance of CD8 cells, IL10, IL12 and IL1 and their role in modulation of the contact allergy reaction. The chemistry of haptens should lead to a decision as to whether a new molecule is allergic or not, as well as the different possibilities of bonding to form sensitizing complexes. Epidemiology and the present development of epicutaneous tests are at the centre of studies that are mentioned in this general review.     

Recent advances in steel cleanliness

At Klöckner Edelstahl in Georgsmarienhütte improvements in steel cleanliness mentioned in this report were concentrated on the tundish and pouring channel. Sealing of the tundish with inert gas curbed reoxidation so that total oxygen after about 1 minute of casting was around 10 ppm, whereas this value was reached only after 25 minutes of casting in the case without inert gas sealing. Reoxidation in the pouring channel may be a danger because of the high pressure drops recorded. Therefore, stringent measures must be observed to prevent reoxidation in the tundish and the pouring channel.     

Molecular advances in pancreatic cancer

The purpose of this study was to quantify in vivo the three-dimensional motion patterns of the sacroiliac joint during passive manipulations as the opinions about the extent of motion of this joint are varied. 12 sacroiliac joints of 6 patients with clinically and radiologically normal joints were investigated. All patients were treated with an external fixator for diagnostic purposes of low back pain unrelated of this study. The motion of the sacroiliac joint was measured continuously with a three-dimensional goniometric system, which was mounted at the end of Schanz screws implanted in S1 and the ilium. All measurements showed relatively small rotation angles around the three main axis to the body between the ilium and the sacrum (< 2 degrees) and very small translations between the screw entry points into the bones (< 1 mm). The maximum rotation angle in the sagittal plane was 1.3 degrees on the right joint and 1.6 degrees on the left joint for flexion plus extension. It is questionable whether this motion can be quantified during manual manipulation. Extension of the hip always produced the largest motion in the sacroiliac joint.     

Biotechnological advances in goat reproduction

Goat selection and reproduction have resulted from using conventional methods of natural mating and artificial insemination. Genetic improvements resulting from these are usually slow. Innovative developments in biotechnology rapidly propagate superior genes, offering hope for modeling and designing animals to fit market and environmental requirements. Use of Tris, citric acid, fructose, egg yolk, and glycerol extender has enabled goat sperm to be stored successfully for several years before being used in cervical or laparoscopic insemination. Laparoscopic recovery of goat embryos to reduce adhesions from repeat surgeries has great potential in improving embryo production for direct transfer or for future transfer after cryopreservation. Goat kids have been produced, as a result of experiments to refine techniques of in vitro maturation and fertilization of recovered oocytes, with successful culture and transfer of embryos. In vitro fertilization technology is also essential for cloning goat embryos and for gene transfer. Transgenic goats have already been produced due to new genes being expressed from biologically active molecules altering the phenotype of the transferred goat. The introduced gene is capable of transmission between generations. The goat's diversified commercial value and convenient size make it a benefactor to new technology for rapid genetic improvement as a supplement to conventional selection methods.     

New advances in endovascular technology

We report an Italian family with maternally inherited encephalomyopathy including progressive external ophthalmoplegia, seizures, and neurophysiological evidence of brainstem dysfunction. Mitochondrial DNA analysis showed a heteroplasmic point mutation at position 5814 in the tRNA gene for cysteine (A5814G), previously reported in a 5-year-old girl of Portuguese origin. The mutation was very abundant (> 95%) in both muscle and blood from the proposita and was present in lower proportions (average 85 +/- 6%) in blood from three less severely affected maternal relatives. This observation confirms pathogenicity for the A5814G mutation.     

Recent advances in infertility treatment

Infertility is defined as the inability to conceive after one year of regular coitus without contraception. Approximately 10% to 20% of childbearing-age couples are infertile in the United States. The demand for infertility investigations has increased dramatically in recent decades. The number of women using infertility services rose from 600,000 in 1968 to 1.35 million in 1988, an increase due, in part, to improved technology and increased publicity that began in the early 1980s. By 1995, the numbers were about 2.7 million. Recent advances in assisted reproductive technologies (ART) have provided greater possibilities for successful infertility treatment. Examples of new technologies include intracytoplasmic sperm injection, oocyte donation, and embryo cryopreservation.