Hierarchically imprinted sorbents

A double imprinting methodology was developed to synthesize novel materials with hierarchical structures. On the microporous level (1-3 A), metal ions served as template. On the mesoporous level (diameters of 25-40 A), micellar structures produced by self-assembly of surfactant molecules were used as templates. Removal of both metal ions and surfactant micelles resulted in the formation of imprints with different sizes within the silica matrix, each with a specific function. This research opens vast opportunities for the applications of ordered mesoporous materials in the area of molecular recognition such as separations, chemical sensors, and catalysts.

[Adsorption of anthraquinone dyes by biosorbent GX2]

The GX2 growing mycelium shows excellent adsorptive capacity on the four kinds of anthraquinone dyes, however, due to the difference of molecular structure of dyes, the adsorption rates are different. Although the dyes show inhibiting effect on the growth of GX2, when the concentration of reactive brilliant blue KN-R is 250 and 400 mg/L, the adsorption rate of dye by the GX2 growing mycelium reaches 100% and 91.4%, respectively. With the increase of salinity (NaCl), the dry weight of GX2 mycelium increases; the diameter of granular mycelium decreases and its adsorption surface area increases accordingly, the salinity shows evident enhancement on the adsorption of reactive brilliant blue KN-R by GX2 growing mycelium in the range of 0%-2% salinity. The adsorption process is influenced by the concentration of carbon source as well, reactive brilliant blue KN-R with the concentration of 120 mg/L can be completely adsorbed only when the concentration of glucose is more than 2.5 g/L. The GX2 growing mycelium has better adsorptive capacity than resting living mycelium and dead mycelium.

[The bindings of typical aldehydes pollutants with cell DNA]

The bindings of 3 kinds of aidehyde pollutants, formaldehyde, acetaldehyde, acrolein, with both prokaryotic and eukaryotic DNA, and their genotoxic effect and mechanism were conducted by the shifts of maximum UV absorption peak to determine binding effects and by HPLC to determine binding sites in vitro model system. The shifts of maximum UV absorption peak of prokaryotic DNA contaminated by 3 kinds of aldehyde pollutants are not significant; but after the DNA extracted from prokaryotic bacteria reacting with formaldehyde in tube, the shifts of maximum UV absorption peak of DNA are significant; the shifts of maximum UV absorption peak of eukaryotic DNA contaminated by 3 kinds of aldehyde pollutants are significant also. The reacition of acetaldehyde with dG reduced by NaBH4 was separated and detected by HPLC, the product was determined qualitatively as N2-ethaldeoxyguanosine adduct. The 3 kinds of aldehyde pollutants could bind with cellular DNA to express genotoxic effects; and the N2 site of deoxyguanosine is the possible covalent binding site.

Neutron detection based upon a lithiated sol-gel glass

The addition of dopants in the wet chemistry formation of glass in sol-gel technology is used for many purposes. Among the uses are the fabrication of films sensitive to pH, temperature, the presence of dissolved chemicals in solutions and many others. This paper describes the use of sol-gel technology for the doping of B-10, Li-6 and U-235 into glass films applied to silicon surface barrier (SSB) detectors. Using a commercial preamp/amplifier and an IEEE-488 NIM counter, the response was recorded of the neutron profile in a neutron activation source. A portable personal computer recorded the thermal neutron map as the detector was lowered in 1.27-cm steps down a Numec thermal neutron activation source. The lithiated glass film on the SSB gave about four times the count rate of the boron-10 doped glass film. The U-235 doped glass film gave a much lower count rate, but maintained a constant output signal due to the presence of the alpha activity from the U-235 and the trace of U-234 present in the sample.

The bi-directional regulation of filamin on the ATPase activity of smooth muscle myosin

OBJECTIVE

The aim of this study is to investigate the functional relationship between filamin, a known actin binding protein, and myosin and the effects of filamin on the interaction between myosin and actin.

METHODS

Ultra-centrifugation method was used to investigate the binding of filamin to both phosphorylated and unphosphorylated myosins. Mg-ATPase activities of both phosphorylated and unphosphorylated myosins in the presence and absence of actin were measured to observe the effects resulted from filamin-actin and filamin-myosin interactions.

RESULTS

It was found that filamin is also a myosin binding protein. Filamin inhibited the actin activated Mg-ATPase activity of phosphorylated myosin and stimulated Mg-ATPase of phosphorylated myosin in the absence of actin; in addition, filamin stimulated Mg-ATPase activity of unphosphorylated myosin in both the presence or absence of actin.

CONCLUSION

The result suggest that the effects of filamin on the myosin Mg-ATPase activities are bi-directional, i.e., stimulatory via binding to myosin and inhibitory via binding to actin.

Optical detection of polycations via polymer film-modified microtiter plates: response mechanism and bioanalytical applications

Microtiter plate wells modified with thin (approximately 20 microm) polymeric films capable of optically sensing macromolecular protamine and other polycationic species are described. The plates are prepared by coating the bottom of each well of a conventional 96-well polypropylene plate with an adherent polymer film (a mixture of poly(vinyl chloride) and polyurethane) containing a lipophilic 2',7'-dichlorofluorescein derivative. Surprisingly, optical response toward polycations is shown to result from the extraction of the fluorescein derivative from the polymer film into a lyophobic colloidal phase at the sample/film interface. This new phase is likely composed of a micellular-type ion pair complex between the analyte polycation from aqueous sample phase and the deprotonated form of the fluorescein derivative. Accumulation of the deprotonated fluorescein species in this interfacial region induces an absorbance change measured at 540 nm. Optimized plates can be used to sense protamine concentrations in the range of 0-100 microg/mL in 10 min with little or no response to physiological levels of common cationic species (Na+, K+, Ca2+, etc.). The modified plates are shown to be useful as simple optical detectors for measuring heparin levels in plasma via titrations with protamine and for monitoring protease activities (trypsin and plasmin) that cleave polycationic peptides/proteins such as protamine into smaller peptide fragments that are not detected by the sensing films. Assays for "clot busting" plasminogen activators (streptokinase, urokinase, and tissue plasminogen activator) are also demonstrated using this relatively simple microtiter plate-based polycation detection system.

[Study on interferon gamma and interleukin-4 contents of plasma and cultured monoclear cell supernatants in patients with endometriosis]

OBJECTIVE

To investigate the cytokin production of T helper cell (Th) 1, Th2 subsets in patients with endometriosis(EM).

METHODS

The cytokine production of Th1, Th2 cells expressed by interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) contents respectively in supernatants of cultured PHA induced peripheral blood mononuclear cell (PBMC) and plasma, obtained from 30 EM patients and 15 normal controls were determined by enzyme linked immunoabsorbent assay (ELISA).

RESULTS

IL-4 contents of EM patients were elevated both in plasma and PBMC supernatants[(32.0 +/- 22.6) ng/L and (32.8 +/- 12.5) ng/L, respectively], while IFN-gamma levels was suppressed in PBMC supernatant as compared with normal controls [(1,095.6 +/- 375.6) ng/L and (1,549.3 +/- 361.9) ng/L, respectively] (P < 0.01, P < 0.05). As a results, the ratio of IFN-gamma/IL-4 decreased in EM patients.

CONCLUSIONS

Changes of IFN-gamma and IL-4 contents in EM patients may reflect functional inbalance between Th1 and Th2 cells, which may play a role in the pathogenesis of EM.

Neuronal distribution and functional characterization of the calcium channel alpha2delta-2 subunit

The auxiliary calcium channel alpha2delta subunit comprises a family of three genes, alpha2delta-1 to 3, which are expressed in a tissue-specific manner. alpha2delta-2 mRNA is found in the heart, skeletal muscle, brain, kidney, liver and pancreas. We report here for the first time the identification and functional characterization of alpha2delta-2 splice variants and their mRNA distribution in the mouse brain. The splice variants differ in the alpha2 and delta protein by eight and three amino acid residues, respectively, and are differentially expressed in cardiac tissue and human medullary thyroid carcinoma (hMTC) cells. In situ hybridization of mouse brain sections revealed the highest expression of alpha2delta-2 mRNA in the Purkinje cell layer of the cerebellum, habenulae and septal nuclei, and a lower expression in the cerebral cortex, olfactory bulb, thalamic and hypothalamic nuclei, as well as the inferior and superior colliculus. As the in situ data did not suggest a specific colocalization with any alpha1 subunit, coexpression studies of alpha2delta-2 were carried out either with the high-voltage-gated calcium channels, alpha1C, alpha1E or alpha1A, or with the low-voltage-gated calcium channel, alpha1G. Coexpression of alpha2delta-2 increased the current density, shifted the voltage dependence of channel activation and inactivation of alpha1C, alpha1E and alpha1A subunits in a hyperpolarizing direction, and accelerated the decay and shifted the steady-state inactivation of the alpha1G current.

A family of gamma-like calcium channel subunits

The gamma subunit was initially identified as an auxiliary subunit of the skeletal muscle calcium channel complex. Evidence for the existence of further gamma subunits arose following the characterization of a genetic defect that induces epileptic seizures in stargazer mice. We present here the first account of a family of at least five putative gamma subunits that are predominantly expressed in brain. The gamma-2 and gamma-4 subunits shift the steady-state inactivation curve to more hyperpolarized potentials upon coexpression with the P/Q type alpha(1A) subunit. The coexpression of the gamma-5 subunit accelerates the time course of current activation and inactivation of the alpha(1G) T-type calcium channel.

[Determination of glycosylated hemoglobin in human erythrocytes by fast protein liquid chromatography system]

The chromatography method for analysis of glycosylated hemoglobin(HbA1c) in human erythocytes was established by using a fast protein liquid chromatography system(FPLC) and a Mono S column. The average intrabatch and interbatch coefficients of variations (n = 3) were 2.5% and 4.8%, respectively. There was a positive correlation between the results of FPLC and routine microcolumn method (r = 0.413, P < 0.02). Using FPLC method, the HbA1c levels in festing blood of 54 normal donors and 26 diabetics on admission were 4.6 +/- 1.19(%) and 10.2 +/- 3.45(%), respectively. A significant difference was found statistically between the results of two groups (t = 10.8, P < 0.01).

How does light regulate chloroplast enzymes? Structure-function studies of the ferredoxin/thioredoxin system

1. Introduction 68

2. Ferredoxin reduction by photosystem I 72

3. Ferredoxins 73

4. Ferredoxin[ratio ]thioredoxin reductase 73

4.1 Spectroscopic investigations of FTR 76

4.2 The three-dimensional structure of FTR from the cyanobacterium Synechocystis sp. PCC6803 77

4.2.1 The variable subunit 77

4.2.2 The catalytic subunit 81

4.2.3 The iron–sulfur center and active site disulfide bridge 82

4.2.4 The dimer 84

4.3 Thioredoxin f and m 85

4.4 Ferredoxin and thioredoxin interactions 86

4.5 Mechanism of action 88

4.6 Comparison with other chloroplast FTRs 92

5. Target enzymes 95

5.1 NADP-dependent malate dehydrogenase 95

5.1.1 Regulatory role of the N-terminal extension 97

5.1.2 Regulatory role of the C-terminal extension 99

5.1.3 Thioredoxin interactions 101

5.2 Fructose-1,6-bisphosphatase 101

5.3 Redox regulation of chloroplast target enzymes 103

6. Conclusion 103

7. Acknowledgements 104

8. References 104

A pre-requisite for life on earth is the conversion of solar energy into chemical energy by photosynthetic organisms. Plants and photosynthetic oxygenic microorganisms trap the energy from sunlight with their photosynthetic machinery and use it to produce reducing equivalents, NADPH, and ATP, both necessary for the reduction of carbon dioxide to carbohydrates, which are then further used in the cellular metabolism as building blocks and energy source. Thus, plants can satisfy their energy needs directly via the light reactions of photosynthesis during light periods. The situation is quite different in the dark, when these organisms must use normal catabolic processes like non-photosynthetic organisms to obtain the necessary energy by degrading carbohydrates, like starch, accumulated in the chloroplasts during daylight. The chloroplast stroma contains both assimilatory enzymes of the Calvin cycle and dissimilatory enzymes of the pentose phosphate cycle and glycolysis. This necessitates a strict, light-sensitive control that switches between assimilatory and dissimilatory pathways to avoid futile cycling (Buchanan, 1980, 1991; Buchanan et al. 1994; Jacquot et al. 1997; Schürmann & Buchanan, 2000).

Effect of intragastric pH on control of peptic ulcer bleeding

BACKGROUND

We have performed series studies to investigate the effect of intragastric pH on control of peptic ulcer bleeding. In laboratory and animal studies, both platelet aggregation and gastric mucosal bleeding time were shown to be extremely sensitive to different pH levels. Platelet aggregation decreased significantly at pH > or = 6.8 and gastric mucosal bleeding time fell significantly at pH > or = 6.4. In a prospective clinical trial, primed infusions of different dosages of omeprazole (8 or 4 mg/h) after a bolus (40 mg) produced consistently high intragastric pH values in patients with bleeding duodenal ulcer. These results were not significantly different from that obtained from omeprazole 40 mg bolus treatment every 12 h (P > 0.05). However, primed injection with cimetidine (800 mg/12 h) was less effective (P < 0.05).

METHODS

In a retrospective analysis, 303 patients with bleeding peptic ulcer who were treated with cimetidine and 326 patients who were treated with omeprazole were compared.

RESULTS

The emergency surgery (4.91%) and mortality rates (1.84%) in the omeprazole group were not significantly different (P > 0.05) from those (7.28 and 1.99%) in the cimetidine group. However, the standardized emergency surgery rate of the omeprazole group (3.28%) was significantly lower than that (9.28%) of the cimetidine group (P < 0.05).

CONCLUSION

We conclude that increased intragastric pH to at least 6.4 with omeprazole is helpful in controlling peptic ulcer bleeding. Chinese patients require a lower dose of omeprazole than their Western counterparts to control ulcer bleeding.

[The effective dielectric function of porous SiO2 glass]

In this paper, we discussed the effective dielectric function of porous SiO2 glass with pore size 7.5 nm. We briefly discussed different formulae proposed by different theoretical models of porous systems, and compared the relationship of effective dielectric functions changing with different porosity of porous SiO2 of each formula. Through comparing the experimental spectra and the theoretical spectra of each formula, we found the equation ln epsilon e = theta 1 ln epsilon 1 + theta 2 + theta 2 ln epsilon 2 best indicates the effective dielectric function of porous SiO2. This work is helpful in selecting special absorption materials.

Redox signaling in chloroplasts: cleavage of disulfides by an iron-sulfur cluster

Light generates reducing equivalents in chloroplasts that are used not only for carbon reduction, but also for the regulation of the activity of chloroplast enzymes by reduction of regulatory disulfides via the ferredoxin:thioredoxin reductase (FTR) system. FTR, the key electron/thiol transducer enzyme in this pathway, is unique in that it can reduce disulfides by an iron-sulfur cluster, a property that is explained by the tight contact of its active-site disulfide and the iron-sulfur center. The thin, flat FTR molecule makes the two-electron reduction possible by forming on one side a mixed disulfide with thioredoxin and by providing on the opposite side access to ferredoxin for delivering electrons.

[New coleopterancidai strains of Bacillus thuringiensis and production of coleopterancide]

Two coleopterancidal strains of Bacillus thuringiensis, YM-03 and SHQ11-10, were isolated from soil in China. H-Serotype of YM-03 was H8a8b, and H-Serotype of SHQ11-10 has not been identified. Both of them produced flat bipyramid-like crystals which consisted of 68-70 kD and 65 kD protein respectively. Bioassay indicated that these two Bt strains were very active on the larva of Leptinotarsa decemlineata and Plagioder aversicolora. They grew prosperously in fermentation. Powder of YM-03 product was high effect against colorado potato beetle in the field experiment.

[The immunohistochemistry and clinic study on surgical margin of laryngeal cancer]

OBJECTIVE

To probe into the safe incisal range of removing laryngectomy cancer determined from the albumen balance of cells.

METHOD

LSAB or SABC of immunohistochemistry was applied, and three groups of samples with cancer tissue, nearby cancer tissue and distal cancer tissue of 36 primary laryngectomy cancer were tested by antibodies p16, p21, TGF-beta 1, PCNA and EGFR.

RESULT

The difference of the positive rate with the five antibodies between the cancer group and the two side incisal group were very notable with P < 0.01 or P < 0.05, but which between nearby cancer tissue and distal cancer tissue were not notable with P > 0.05. The differences of the positive rates with 5 antibodied between high differentiation group and low differentiation group were notable with P < 0.05, and P < 0.05 with PCNA in the group whether the lymphonodi cervicales transmitted or not. The incisals for all the cases are beyond 5 mm, the recurerence rate is 3%.

CONCLUSION

The 5 mm incisal for laryngectomy cancer is appropriate on the albumen cevel of cells.

Validity of echocardiographic measurement in an epidemiological study. Project HeartBeat!

In Project HeartBeat!, a longitudinal study of cardiovascular disease risk factors in healthy children and adolescents, 3 samples of 40, 80, and 182 echocardiograms, respectively, were randomly selected and reread to evaluate intraobserver and interobserver variabilities and comparability between measurements of field echocardiographic technicians and reference readings at Texas Children's Hospital. Included in the evaluation were 8 M-mode echocardiographic measurements, ie, aortic root diameter, left atrial diameter, and end-diastolic and end-systolic measurements of interventricular septal thickness, left ventricular (LV) diameter, and LV posterior wall thickness; 8 Doppler measurements; and a calculated LV mass. Means and SDs of the differences of the paired measurements were used to assess the relative bias and random error of the measurements. For the intraobserver comparison, means and SDs of the differences were very small, indicating that the echo measurements were performed consistently by each project echo technician. Interobserver comparison showed statistically but not clinically significant differences between the paired readings of end-diastolic septal thickness, end-systolic LV posterior wall thickness, and 5 Doppler measurements. Comparison with reference readings at Texas Children's Hospital showed significant differences in diastolic LV diameter, systolic septal thickness, and right ventricular ejection time. These differences, however, were minimal with limited clinical significance. Mean differences in LV mass for the corresponding comparisons were -1.82, 4.50, and 0.0013 g, and the SDs were 18.79, 24.16, and 12.35 g, respectively. We conclude that the echocardiographic measurements taken from healthy children in a longitudinal study can be made accurately with acceptable reproducibility.

[The clinical significance of preserving superior epigastric vessels in Cohen incision]

OBJECTIVE

To study the clinical significance of preserving epigastric vessels in Cohen incision.

METHODS

42 cases of pregnant women were performed cesarean section using Cohen incision. One side vessel of incision was preserved, the other side was cut off. By self control comparison, skin temperature of two sides incision has been taken by CET (computer electric infrared thermograph) on the third day post operation. The thinkness of scar was measured with vernier calipers on the 40th day post operation.

RESULTS

The skin temperature difference between both sides of incision was (0.098 +/- 0.088) degree C. On the cut side the skin temperature was higher than that of the other side (P < 0.01). The scar thickness of cut side was (3.61 +/- 0.61) mm, the other side was (3.10 +/- 0.68) mm. The difference was significant (P < 0.01).

CONCLUSION

The inflammatory reaction and formation of scar can be decreased by means of preserving superior epigastric vessels in Cohen incision.

Colloidal bismuth pectin: an alternative to bismuth subcitrate for the treatment of Helicobacter pylori--positive duodenal ulcer

BACKGROUND

Bismuth triple therapy provides consistently good results in Helicobacter pylori eradication worldwide, whereas quadruple therapy using a combination of omeprazole and bismuth triple regimen has produced cure rates in excess of 90%. The prevalence of metronidazole-resistant strains was 26.8% in our area. Colloidal bismuth pectin (CBP) is a new, lower-priced bismuth salt made in China. The purpose of this study was to investigate the efficacy and safety of CBP triple and quadruple regimens in the treatment of H. pylori-positive duodenal ulcer.

MATERIALS AND METHODS

In this prospective trial, 205 patients with H. pylori-positive duodenal ulcer were allocated randomly to receive one of four regimens: metronidazole, 200 mg; amoxicillin, 250 mg; and colloidal bismuth subcitrate (CBS), 120 mg (group 1), or CBP, 100 mg qid (group 2) for 2 weeks, then continued CBS, 240 mg, or CBP, 200 mg bid for a further 2 weeks. A quadruple regimen using a combination of omeprazole, 20 mg bid, and CBS triple therapy (group 3) or CBP triple therapy (group 4), respectively, was given to patients for 1 week, followed by omeprazole, 20 mg once daily for a further 3 weeks. Further endoscopy was performed at least 4 weeks after cessation of the treatment. H. pylori status was determined by histology, a 14C urea breath test, and a urease test.

RESULTS

The per-protocol H. pylori cure rates were 85% (22 of 26 patients), 90% (35 of 39), 96% (46 of 48), and 95% (75 of 79) for groups 1 through 4. In the intention-to-treat analysis, cure rates were 79% (22 of 28), 83% (35 of 42), 90% (46 of 51), and 89% (75 of 84), respectively. The cure rates of quadruple therapy were higher than those of triple therapy; an 8.2% difference was not statistically significant (95% confidence interval [CI], 2.3-18.7%). The ulcer-healing rates were 88%, 87%, 98%, and 97%, respectively, for groups 1 through 4. The ulcer pain was relieved more rapidly in quadruple- than in triple-therapy regimens. Two patients discontinued treatment prematurely owing to drug-related side effects.

CONCLUSION

One-week quadruple therapy is highly effective and safe in H. pylori eradication in Chinese patients. CBP is as effective as CBS.

[The two-step three-photon resonant ionization of atom Cu]

This paper discusses the process of resonant laser ablation (RLA), where the two-step three-photon resonant ionization of copper is considered as the best scheme. The rate equations of resonant ionization of copper are calculated and the factors that affect the ionization efficiency are discussed. The results prove the potential advantages of RLA especially the low energy threshold.

[The identification of 5 new serotypes of Bacillus thuringiensis from soil in China]

Five new strains of Bacillus thuringiensis(Bt) from soil in China were classified. 5 new H-serotypes: H42, H43, H56, H60 and H62 were identified. There were some distinction in the morphology, biochemical reaction and toxicity against species of insect. Five new Bt subspecies were identified as follows: Strain YGd22-03 Bacillus thuringiensis subsp. jinghongiensis, H42; Strain KK31-01 Bacillus thuringiensis subsp. guiyangiensis, H43; Strain SCg04-02 B. thuringiensis subsp. rongseni, H56; Strain NXP15-04 B. thuringiensis subsp. pingluonsis, H60; Strain HZ39-04 B. thuringiensis subsp. zhaodongensis, H62.