Crystal structure determination of the β-cyclodextrin-p-aminobenzoic acid inclusion complex from powder X-ray diffraction data.

The 1:1 inclusion complex of β-cyclodextrin and p-aminobenzoic acid was prepared and characterized by TG-DTA. The crystal structure of the complex was solved directly from powder X-ray diffraction data using the direct space approach and refined using Rietveld refinement techniques. The complex crystallizes in monoclinic P2(1) space group, with unit cell parameters a=20.

Determination of linear alkylbenzene sulfonates by ion-pair solid-phase extraction and high-performance liquid chromatography.

In this paper, the potential use of multiwalled carbon nanotubes (MWCNTs) as solid phase extraction (SPE) adsorbent was evaluated for preconcentration of linear alkylbenzene sulfonates (LAS) using ion-pair (IP)-SPE with tetrabutylammonium hydroxide (TBAH). The LAS homologues present in the aqueous sample were ion-paired with TBAH and the solution was passed through the MWCNT cartridges. The analytes retained in the cartridge were eluted with methanol and the concentrated methanol extract was analysed by HPLC-UV.

The expression and function of glucose-dependent insulinotropic polypeptide in the embryonic mouse pancreas.

Objective: Glucose-dependent insulinotropic polypeptide (GIP) is a member of a structurally related group of hormones that also includes glucagon, glucagon-like peptides, and secretin. GIP is an incretin, known to modulate glucose-induced insulin secretion. Recent studies have shown that glucagon is necessary for early insulin-positive differentiation, and a similar role for incretins in regulating embryonic insulin-positive differentiation seems probable.

[Proliferation of tissue-engineered cartilage cells under compressive stress].

Objective: To investigate the proliferation of tissue-engineered cartilage cells stimulated by different intensities of compressive stress.

Methods: Human embryonic cartilage cells were seeded into type II collagen sponge scaffold. The cells of the pressure groups were stimulated by different compression rate (0-5%, 0-10%, and 0-20%) at a cyclical frequency of 0.

Embryonic mouse blood flow and oxygen correlate with early pancreatic differentiation.

The mammalian embryo represents a fundamental paradox in biology. Its location within the uterus, especially early during development when embryonic cardiovascular development and placental blood flow are not well-established, leads to an obligate hypoxic environment. Despite this hypoxia, the embryonic cells are able to undergo remarkable growth, morphogenesis, and differentiation.

Theoretical study on the electronic absorption spectra and molecular orbitals of ten novel ruthenium sensitizers derived from N3 and K8.

Ten novel sensitizer candidates Ru2, Ru4, Ru5, Ru6, Ru7, Ru8, Ru9, Ru10, Ru11 and Ru12 derived from the sensitizers N3 and K8 were designed and studied using the density functional theory and time-dependent density functional theory calculations. The influences of the C=C double bonds between the carboxyl groups and the bipyridine ring as well as the numbers and positions of the -CN groups adjacent to the carboxyl groups on the properties of the sensitizer candidates were discussed. The energy levels and the spatial distributions of the frontier molecular orbitals as well as the electronic absorption spectra of these complexes were compared with those of N3 and K8.

[Raman micro spectroscopic analysis of relationship between DNA degradation in tissue cells and postmortem interval].

The present work is to study the relationship between DNA degradation in tissue cells and estimation of postmortem interval, and to provide a new way for the estimation of postmortem interval (PMI). The tissue cells of kidney and liver in vitro obtained at different time points were kept in a controlled environment. The kidney tissue and liver tissue were taken out every 4 h, during 48-72 h after death at 25 degrees C.

[A study on the targeting collect character of ferromagnetic drug carrier particles in microvasculature].

The transport and capture of therapeutic magnetic particles in the human microvasculature is studied numerically. Taking into account the dominant magnetic and fluidic forces on the particles, we have shown in our study that the particles can be directed to and concentrated at the desired zone which is within a few centimeters from the surface of the body. In addition, we have analyzed the influences of the malignant tissue depth, of the nanometers-iron nuclide content in a particle, and of the blood flow velocity and blood vessel diameter upon the captured efficiency.

Influence on the osteogenic activity of the human bone marrow mesenchymal stem cells transfected by liposome-mediated recombinant plasmid pIRES-hBMP2-hVEGF165 in vitro.

Bone marrow mesenchymal stem cells (BMSCs) is an attractive option for use as seed cells in tissue engineering strategies. Bone morphogenetic proteins (BMPs) to be involved in the formation of various tissue types including bone, cartilage, tendon, and ligament. Vascular endothelial growth factor (VEGF) is a promising reagent for inducing angiogenesis.

Real time three-dimensional transthoracic echocardiography evaluation in a patient with congenital pulmonary vein stenosis.

Although real time three-dimensional transthoracic echocardiography (RD-3DTTE) has been used in children with complex congenital heart diseases, the benefit of RD-3DTTE as a vision of the pulmonary veins still requires further evaluation. We present here, a 3-year-old girl with a stenosis of the left upper pulmonary vein (LUPV). Excellent images were obtained rapidly by RD-3DTTE that successfully visualized the narrowing at the junction of the LUPV.

Endocrine-committed progenitor cells retain their differentiation potential in the absence of neurogenin-3 expression.

Neurogenin-3 (ngn-3) expression is critical for endocrine development in the developing pancreas. We found that when ngn-3 was inhibited in an E11.5 pancreas, using either morpholino antisense or siRNA, it led to a significant decrease in endocrine differentiation after seven days in culture.

Simultaneous determination of tolbutamide, omeprazole, midazolam and dextromethorphan in human plasma by LC-MS/MS--a high throughput approach to evaluate drug-drug interactions.

Drug-drug interactions involving cytochrome P450 (CYP450s) are an important factor for evaluation of a new chemical entity (NCE) in drug development. To evaluate the potential inhibitory effects of a NCE on the pharmacokinetics of a cocktail of representative probes of CYP enzymes (midazolam for CYP3A4, tolbutamide for CYP2C9, omeprazole for CYP2C19 and dextromethorphan for CYP2D6) and the safety and tolerability of the NCE in the presence of probe substrates, a high throughput liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of tolbutamide, omeprazole, midazolam and dextromethorphan in human plasma using tolbutamide-d(9), midazolam-d(4), (+/-)-omeprazole-d(3), and dextromethorphan-d(3) as the internal standards (ISs). Human plasma samples of 50 microL were extracted by a simple protein-precipitation procedure and analyzed using a high performance liquid chromatography electrospray tandem mass spectrometer system.

[Determination of fenbutatin oxide residue in orange products by gas chromatography].

An analytical method for the determination of fenbutatin oxide (FBT) residue in oranges by capillary gas chromatography-flame photometric detection (GC-FPD) was developed. The FBT was extracted with acetone-acetic acid (99:1, v/v) and hexane, filtered and evaporated by nitrogen evaporator in a water bath at 35 degrees C. The residue was dissolved in hexane.

Comparison of respiratory-induced variations in photoplethysmographic signals.

Photoplethysmography (PPG) is an optical method for detecting blood volume changes in tissue. Respiratory-induced intensity, frequency and amplitude variations are contained in the PPG signal; thus, an understanding of the relationships between all of these variations and respiration is essential to advancing respiration monitoring based on PPG. This study investigated correlations between respiratory-induced variations extracted from PPG and simultaneous respiratory signals.

[Study on viral pathogens for infant diarrhea in Chizhou, Anhui].

Objective: To understand the major viral pathogens for infant diarrhea in Chizhou, Anhui.

Methods: Fecal specimens were collected from 428 infants hospitalized with diarrhea in People's Hospital of Chizhou, Anhui between January 2005 and December 2006. Enzyme immunoassay (EIA) and enzyme-linked immunosorbent assay (ELISA) were performed to detected specific antigens of rotavirus, astrovirus, adenovirus or calicivirus.

Theoretical screening of -NH2-, -OH-, -CH3-, -F-, and -SH-substituted porphyrins as sensitizer candidates for dye-sensitized solar cells.

Following former studies, the donor-acceptor combinations of -NH(2)-substituted porphyrin donor and the acceptors C, D, E, F, H and G, those of -OH-, -CH(3)- and -Ph-substituted porphyrins as well as porphine donors and the acceptors E, G, and H, and those of -F- and -SH-substituted porphyrin donors and the acceptor G as novel sensitizer candidates have been designed and calculated at the density functional B3LYP level. The result shows that -NH(2)-, -OH- and -CH(3)-substituted porphyrins as donors combined with the acceptor G are very promising to provide good performances as sensitizers because of their smaller HOMO-LUMO gaps, much red-shifted absorption bands, and good frontier molecular orbital spatial distributions. They are all promising to challenge the current photon-to-current conversion efficiency record 7.

Detection of respiratory rhythm from photoplethysmographic signal by adaptive morphological filter.

An approach using morphological filter technique is proposed to determine the respiratory rhythm from the photoplethysmographic (PPG) signal. As the structuring elements of morphological filter have a decisive effect on the analysis result, in the study the structuring elements are determined by the individual heart rate adaptively. The procedure was tested on a group of healthy subjects.

Systemic administration of arecoline reduces ethanol-induced sleeping through activation of central muscarinic receptor in mice.

Background: Epidemiological evidence of co-use of alcohol and areca nuts suggests a potential central interaction between arecoline, a major alkaloid of areca and a muscarinic receptor agonist, and ethanol. Moreover, the central cholinergic system plays an important role in the depressant action of ethanol and barbiturates. The purpose of this study was to investigate the effects of arecoline on pentobarbital- and ethanol-induced hypnosis in mice.

Substituent effect on the meso-substituted porphyrins: theoretical screening of sensitizer candidates for dye-sensitized solar cells.

According to the concepts of attribute axis and attribute coordinate system, porphine and 11 kinds of bridge carbon substituted porphyrins as donors and 9 common acceptors A-I have been designed and calculated at the density functional B3LYP level. The substituent effects on the molecular orbital energy levels of the porphyrin derivatives have been discussed and promising donor-acceptor combinations are screened. Several novel zinc metalloporphyrins selected were then calculated by means of the DFT/TDDFT method in THF solvent.

Molecule design and screening of novel unsymmetrical zinc phthalocyanine sensitizers for dye-sensitized solar cells.

The molecular orbital and optical properties of the dyes PCH001 and TT1 reported previously were studied using the density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations. The results show that the electronic spectra simulated for PCH001 and TT1 in ethanol were in good agreement with the experimental data. The molecular orbital spatial orientation was used to interpret the discrepancy of the photovoltaic performances of the PCH001 and TT1 sensitized solar cells.

Probe binding to host proteins: a cause for false positive signals in viroid detection by tissue hybridization.

Molecular hybridization assay, especially involving the use of tissues directly, has been developed as a rapid, simple and important technique for plant pathogen detection and/or gene expression analysis on a large scale. In theory, this method relies on the specific binding of a labeled probe to a target nucleotide sequence. However, occasional false positive reactions can pose a problem in its application and the cause is often not well understood.

Kinetics and mechanism of para-chlorophenol photoconversion with the presence of nitrite in ice.

The photochemistry of para-chlorophenol (4-CP) under UV irradiation by using a 125-W high-pressure mercury lamp as light source with the presence of nitrite in a solid water ice matrix had been studied. The experiments were carried out in a photochemical cold chamber reactor at -14 to -12 degrees C. Each influence factor of the 4-CP photoconversion kinetics in the water ice was inspected.

[A multi-gene DNA vaccine encoding non-fusion membrane-anchoring antigen against Schistosoma japonicum].

Objective: To construct DNA vaccine (pIRES-Sj97-Sj14-Sj26) and study its immunogenicity and protective immunity against Schistosoma japonicum.

Methods: The plasmid pIRES-Sj97-Sj14-Sj26 containing fatty binding protein (Sj14), GST (Sj26) and paramyosin (Sj97) was constructed and expressed on the membrane. RT-PCR was used to detect the expression of Sj14 mRNA, Sj26 mRNA and Sj97 mRNA in the Hela cells, and IFA for detecting the expression of trans-membrane Sj14, Sj26 and Sj97.

[Determination of melamine in milk and milk powder by high performance capillary electrophoresis].

A high performance capillary electrophoresis (HPCE) method has been established for the separation of melamine in milk and milk powder. The separation was carried out on a fused-silica uncoated capillary column (58.5 cm x 75 microm).

A new Tn1546 type of VanB phenotype-vanA genotype vancomycin-resistant Enterococcus faecium isolates in mainland China.

VanB phenotype-vanA genotype vancomycin-resistant Enterococcus faecium (VREF) has never been reported in mainland China. We investigated the frequency and molecular characteristics of this strain in a Beijing tertiary hospital. Of 23 vanA genotype VREF clinical isolates, 12 (54.