Toxicological analysis points to a lower tolerable daily intake of melamine in food.

Intensified food safety concern over melamine has prompted national authorities to assess its tolerable daily intake (TDI) for protection of general population including young children. TDI is calculated by dividing a no-observed-adverse-effect level (NOAEL) by a safety factor (SF). Based on appropriate choices of values, the US Food and Drug Administration determined two TDI values in the unit of mg per kg body weight per day as first 0.

Observation of unconventional quantum spin textures in topological insulators.

A topologically ordered material is characterized by a rare quantum organization of electrons that evades the conventional spontaneously broken symmetry-based classification of condensed matter. Exotic spin-transport phenomena, such as the dissipationless quantum spin Hall effect, have been speculated to originate from a topological order whose identification requires a spin-sensitive measurement, which does not exist to this date in any system. Using Mott polarimetry, we probed the spin degrees of freedom and demonstrated that topological quantum numbers are completely determined from spin texture-imaging measurements.

Effect of pulsed electromagnetic field on the proliferation and differentiation potential of human bone marrow mesenchymal stem cells.

Pulsed electromagnetic fields (PEMFs) have been used clinically to slow down osteoporosis and accelerate the healing of bone fractures for many years. The aim of this study is to investigate the effect of PEMFs on the proliferation and differentiation potential of human bone marrow mesenchymal stem cells (BMMSC). PEMF stimulus was administered to BMMSCs for 8 h per day during culture period.

Bilateral paramedian thalamic and mesencephalic infarcts in a newborn due to occlusion of the artery of Percheron.

Bilateral paramedian thalamic and mesencephalic infarcts are infrequently reported in adults, and to our knowledge, has never been reported in a child. The presumed etiology is an occlusion of the artery of Percheron, an uncommon vascular variation, in which a single common trunk from one of the P1 segments of the posterior cerebral artery provides bilateral irrigation to the paramedian thalami and midbrain. Bilateral paramedian thalamic and mesencephalic infarcts in adults are associated with symptoms of decreased arousal, vertical gaze paresis, mood changes, and memory difficulties.

Population physiologically based pharmacokinetic modeling for the human lactational transfer of PCB-153 with consideration of worldwide human biomonitoring results.

Background: One of the most serious human health concerns related to environmental contamination with polychlorinated biphenyls (PCBs) is the presence of these chemicals in breast milk.

Objectives: We developed a physiologically based pharmacokinetic model of PCB-153 in women, and predict its transfer via lactation to infants. The model is the first human, population-scale lactational model for PCB-153.

Correlation between the urine profile of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone metabolites and N7-methylguanine in urothelial carcinoma patients.

A major carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is present in cigarette smoke and its metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), is used as an exposure biomarker for environmental tobacco smoke (ETS). This metabolite (NNAL) can be either detoxified into glucuronidated NNAL (NNAL-Gluc) or activated into an unstable reactive metabolite that methylates DNA along with formation of 4-hydroxy-4-(3-pyridyl)-butyric acid [hydroxy acid (HA)]. Therefore, the carcinogenic risk associated with ETS exposure is greatly modulated by individual variations in metabolic activation and detoxification capabilities.

PM2.5 and associated polycyclic aromatic hydrocarbon and mutagenicity emissions from motorcycles.

In this study, PM(2.5) in diluted exhausts of motorcycles are collected and emission characteristics of PM(2.5)-associated polycyclic aromatic hydrocarbons (PAHs) and mutagenicities are investigated.

Infantile seizures: infants are not just little children.

Seizure semiology in infants defies the typical characteristics and classification schemata that have been developed for older children and adults. A clear classification system is a necessary first step to facilitate proper diagnosis, choice of treatment, and determination of prognosis. This is an especially challenging task with seizures in infants.

Immunoglobulin E and matrix metalloproteinase-9 in patients with different stages of coronary artery diseases.

The aims of this study were to identify levels of total immunoglobulin E (IgE) and matrix metalloproteinase (MMP)-9 in patients with different stages of coronary artery diseases. IgE, MMP-9, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), total cholesterol, low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL) and triglyceride (TG) were measured by fluorescence enzyme immunoassay, gelatin zymography, and autoanalyzer in normal subjects (n = 40), patients with stable angina pectoris (SAP, n = 40), patients with unstable angina pectoris (UAP, n = 40), patients with acute myocardial infarction (AMI, n = 40), or post-CABG-surgery of those acute myocardial infarction (P-CABG, n = 40). Compared with normal subjects, increased IgE but unchanged MMP-9, CPK, LDH were found in SAP group and UAP group, whereas IgE, MMP-9, CPK and LDH levels were all significantly increased in AMI group.

A topological Dirac insulator in a quantum spin Hall phase.

When electrons are subject to a large external magnetic field, the conventional charge quantum Hall effect dictates that an electronic excitation gap is generated in the sample bulk, but metallic conduction is permitted at the boundary. Recent theoretical models suggest that certain bulk insulators with large spin-orbit interactions may also naturally support conducting topological boundary states in the quantum limit, which opens up the possibility for studying unusual quantum Hall-like phenomena in zero external magnetic fields. Bulk Bi(1-x)Sb(x) single crystals are predicted to be prime candidates for one such unusual Hall phase of matter known as the topological insulator.

Decomposition of dimethyl phthalate in an aqueous solution by ozonation with high silica zeolites and UV radiation.

This study investigates the enhanced ozonation of dimethyl phthalate (DMP), which is a pollutant of concern in water environments, with high silica zeolites and ultraviolet (UV) radiation. Semibatch ozonation experiments are performed under various reaction conditions to examine the effects of inlet gas ozone concentration, high silica zeolite dosage, and UV radiation intensity on the decomposition of DMP. The complete removal of DMP can be efficiently achieved via both O(3) and O(3)/UV treatments.

Fast optical recording in dye-doped polymer-dispersed liquid-crystal films.

We describe a fast optical recording material based on a dye-doped polymer-dispersed liquid-crystal film. A holographic grating is written in this film with a single Q -switched Nd:YAG laser pulse that has a duration of ~6 ns . Such a grating is due to the reorientation effect of the liquid-crystal molecules through interaction with the photoinduced adsorption of the doped azo dyes.

Anomalous Metallic State of Cu0.07TiSe2: an optical spectroscopy study.

We report an optical spectroscopy study on the newly discovered superconductor Cu0.07TiSe2. Consistent with the development from a semimetal or semiconductor with a very small indirect energy gap upon doping TiSe2, it is found that the compound has a low carrier density.

Enhancements of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) metabolism and carcinogenic risk via NNK/arsenic interaction.

Epidemiological studies indicated an enhancement of cigarette smoke-induced carcinogenicity, including hepatocellular carcinoma, by arsenic. We believe that arsenic will enhance the expression of hepatic CYP2A enzyme and NNK metabolism (a cigarette smoke component), thus its metabolites, and carcinogenic DNA adducts. Male ICR mice were exposed to NNK (0.

P38 mitogen-activated protein kinase pathways are involved in the hypertrophy and apoptosis of cardiomyocytes induced by Porphyromonas gingivalis conditioned medium.

The surrounding medium of periodontal pathogen Porphyromonas gingivalis (P. gingivalis) increased cardiomyocyte hypertrophy and apoptosis whereas Actinobaeillus actinomycetemcomitans and Prevotella intermedia had no effects. The purpose of this study is to clarify the role of p38 pathway in P.

Liquid chromatography/tandem mass spectrometric method for the simultaneous determination of tobacco-specific nitrosamine NNK and its five metabolites.

A sensitive and robust high-performance liquid chromatography-electrospray ionization tandem mass spectrometry method to analyze 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its five metabolites in one passage was developed and validated. The method achieved excellent reproducibility and accuracy. Linearity was observed for all six compounds (R(2)=0.

Semimetal-to-semimetal charge density wave transition in 1T-TiSe(2).

We report an infrared study on 1T-TiSe(2), the parent compound of the newly discovered superconductor Cu(x)TiSe(2). Previous studies of this compound have not conclusively resolved whether it is a semimetal or a semiconductor-information that is important in determining the origin of its unconventional charge density wave (CDW) transition. Here we present optical spectroscopy results that clearly reveal that the compound is metallic in both the high-temperature normal phase and the low-temperature CDW phase.

Home parenteral nutrition support in adults: experience of a medical center in Asia.

Background: Parenteral nutrition (PN) support is mandatory in patients with gut failure. Short bowel syndrome is a term used for symptoms and pathophysiological disorders brought about by the removal or malfunction of a large portion of the small bowel. Inflammatory bowel disease, vascular disease, and malignancy are the most common causes of short bowel syndrome in adults.

Emergence of Fermi pockets in a new excitonic charge-density-wave melted superconductor.

A superconducting state (T(c) approximately 4.2 K) has very recently been observed upon successful doping of the charge-density-wave (CDW) ordered triangular lattice TiSe(2), with copper. Using state-of-the-art photoemission spectroscopy we identify, for the first time, momentum-space locations of doped electrons that form the Fermi sea of the superconductor.

Inorganic arsenic exposure and its relation to metabolic syndrome in an industrial area of Taiwan.

Past arsenic exposure was found associated with increased incidence of type 2 diabetes. However, the mechanisms remain unclear. Metabolic syndrome has been shown as a strong predictor for diabetes occurrence.

The non-genomic effects on Na+/H+-exchange 1 by progesterone and 20alpha-hydroxyprogesterone in human T cells.

Progesterone is an endogenous immunomodulator and can suppress T-cell activation during pregnancy. We have previously shown that the non-genomic effects of progesterone, especially acidification, are exerted via plasma membrane sites and suppress cellular genomic responses to mitogens. This study aimed to show that acidification is due to a non-genomic inhibition of Na(+)/H(+)-exchange 1 (NHE1) by progesterone and correlate this with immunosuppressive phytohemagglutinin (PHA)-induced T-cell proliferation.