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The effects of Citri Reticulatae Pericarpium (CRP) and grapefruit juice (GFJ) on the pharmacokinetics of omeprazole were investigated in this study. Sprague-Dawley rats were pretreated with CRP decoction or GFJ for 28 consecutive days. After a single intragastric administration of 6.0 mg/kg, the concentration of omeprazole in the plasma was determined by high-performance liquid chromatography (HPLC), and the pharmacokinetic parameters were calculated by Kinetica software 5.0. A high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (HPLC-Q-TOF-MS) method was established to identify the chemical components in CRP decoction and GFJ. The results showed that the AUCt -∞ was significantly increased when coadministrated with CRP. The AUC0- t and AUC0-∞ was remarkably increased; the Cl was decreased when coadministrated with GFJ. A total of 31 and 28 bioactive compounds were identified in the CRP decoction and GFJ, respectively. Flavonoids and furanocoumarins, including hesperidin, hesperetin, naringenin, sinensetin, tangeretin, nobiletin, and 6',7'-dihydroxybergamottin, were simultaneously identified in CRP decoction and GFJ. This study indicates that the increased bioavailability of omeprazole may be due to the inhibition of hepatic cytochrome P450 enzymes, and the systemic exposure should be monitored when concomitant administration with CRP and GFJ. PRACTICAL APPLICATIONS: Citri Reticulatae Pericarpium (CRP) has been widely consumed as a daily condiment, functional food, and a traditional Chinese medicine. Omeprazole, primary metabolized by CYP450 enzymes, was usually coadministered with CRP for the treatment of gastrointestinal disease. Studies have confirmed that much fruit juices, including grapefruit juice, may affect drug metabolism enzymes. CRP and grapefruit (Citrus paradisi Macf.) belong to the genus Citrus and family Rutaceae with different species. Therefore, the pharmacokinetic interaction of CRP decoction and grapefruit juice with omeprazole is worthy of attention. The results of this study can provide basic pharmacological data support for the safe and effective clinical use of omeprazole. It can also provide a theoretical basis for the development of new functional products and daily application of CRP.

Lotus (Nelumbo nucifera Gaertn.) seeds are rich in proteins and are considered to be a beneficial source of plant proteins. In this study, lotus seed protein hydrolysate (LSPH) was prepared using Flavourzyme and antioxidant activities were evaluated. The LSPH possessed the highest DPPH-scavenging (EC50 2.9 mg/mL), H2O2-scavenging (EC50 16.1 mg/mL), and reducing power activity (8.0 mg/mL) at 180 min of hydrolysis. After gel filtration and reverse phase HPLC purification, the low molecular weight fraction was then analyzed by Nano-LC-MS/MS. Sixteen peptides with corresponding mass from 1 to 2 kDa were identified. Peptides with hydrophobic features and acidic amino acids, Asp and Glu, are considered to contribute to overall antioxidant activities. These results show Flavourzyme hydrolysis of lotus seed protein successfully generates low molecular fragments that make them a potential nutraceutical or health promoting supplement.

The objective of this study was to evaluate the antioxidant activities of Mesona procumbens ethanolic extracts (MPEEs) which displayed variable antioxidant levels with different ethanolic concentrations. Compared to MPEEs with 20, 40 and 80% ethanol, the 60% MPEE exhibited a higher total phenol content (TPC), total flavonoid content (TFC), 1,1-diphenyl-2-picryl hydrazyl (DPPH)- and 2,2-azino-bis-(3-ethyl benzothiazoline-6-sulphonic acid (ABTS)-scavenging activities, reducing power, protection of Raw 264.7 mouse macrophages against H2O2-induced damage, and inhibition of reactive oxygen species (ROS) induced by 2,2-azobis(2-amidino propane) dihidrochloride (AAPH). IC50 values of DPPH and ABTS radicals by MPEEs were highly and significantly associated with TPCs and TFCs. The most significant protective effect against oxidative DNA damage was also found to be the 60% MPEE at a concentration of 3.6 mg/mL. In addition, the cell viability test showed that none of the MPEEs had any cell toxicity up to a concentration of 250 μg/mL. The 60% MPEE exhibited higher in vitro and ex vivo antioxidant activities, possessed a protective capability for the biological membrane system, and can be used as a functional ingredient representing a potential source of natural antioxidants to prevent and treat oxidative stress-related disorders.

Black soybeans are commonly consumed as health foods and used in traditional Chinese medicine, but they are rarely cultivated as edible sprouts. During germination, the composition of seeds undergoes distinct changes that cause variations in bioactivities. In this study, the water-soluble black soybean polysaccharide (BSPS) was isolated from sprouts harvested at two-day intervals during the first week of seedling growth. The chromatographic profiles of the BSPS in ungerminated seeds showed fraction 1 (F1, about 64kDa) and fraction 2 (F2

Combined of refractory metal W and ultra-high temperature ceramic ZrC, W/ZrC ultra-high temperature cermets have exhibited high temperature strength, excellent resistance to thermal shock and ablation, possessing a wide application prospect in high temperature fields. At present, W/ZrC cermets are mainly fabricated by Hot Pressing (HP), Spark Plasma Sintering (SPS), in Situ Reactive Sintering (SRS) and Displacive Compensation of Porosity (DCP). Characters and developments of all these fabrications are reviewed in this paper, and a comparison of advantages and shortages between them is made, also the properties of W/ZrC cermets are analyzed. At last, the development directions of future work are prospected.

Summary Objective Because of rapid alterations in lifestyle and the incidence of metabolic syndrome (MetS), the prevalence of carotid atherosclerosis (CA) and carotid plaque (CP) may increase in China. We aimed to evaluate the prevalence of CA and CP as well as its relation to MetS in an East Chinese population. Methods The study included 6142 subjects who underwent general health screening including carotid ultrasonography in 2009. Diagnoses of MetS were made according to the revised Adult Treatment Panel III criteria. Results The prevalence of CA and CP increased gradually with age. These conditions were more prevalent in men than in women (CA: 22·1%vs 12·0%, P

The C–H···O hydrogen bond in trisialic acid lactones has been examined by using long-range COSY (LRCOSY) and ab initio calculations. From an analysis of the LRCOSY spectra, 3J correlations of BH9ax/AH8 and CH9ax/BH8 confirmed the existence of hydrogen-bond connections of x+1C9–x+1H9ax···xO8. The theoretical bond energy of the hydrogen bond was estimated to be 1.0 or 1.6 kcal/mol by using two models. The acid-catalyzed cooperative lactonization of oligosialic acids can be understood in terms of the additional C–H···O stabilization in the lactone product. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

The conformation of the trisialic acid lactone α2,8-(NeuAc)3 was analyzed by a combination of NMR spectroscopy, molecular modelling and molecular dynamic (MD) calculations. The interresidue NOEs provided 14 important distance restraints for the molecular simulation, and the final simulated structures showed a root mean square deviation of 0.78 for all superimposed structures. Because of the steric hindrance from the spirobicyclic δ-lactone, the individual sialic acid pyranose rings are considered essential in the chair 5C2 conformation. In addition, lactone I close to the nonreducing end adopted a half-chair A2HCB9 conformation, whereas lactone II, which is close to the reducing end adopted a skewed twist-boat C2SC9 conformation. In the NMR solution structure and in the 1.0-ns, in-water MD calculation, the final simulated structures are in the exocyclic torsions (ω7, ω8) = (gauche–anti) surface of the energy adiabatic map, where the global minimum can be found. During the in-water MD simulation, a slight fluctuation in the structure was observed, reflecting the steady conformation of the lactone and the middle residue of the trisaccharide. These data are consistent with a theoretical approach of polysialic acid (PSA) polylactone with torsions (ω7, ω8) = (65°, 175°) and (Φ, Ψ) = (75.8°, –112.4°). Thus, we conclude that the PSA polylactone is a right-hand helix with a rotation angle, μ, of 240° and a repeating unit, n, of 1.5 residues. The structural properties of the PSA lactone discussed within this context differ from the helical epitope of G2+ PSA and may serve in future PSA-related antigen designs. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

A sensitive and efficient method using high-performance CE (HPCE) and neuraminidase hydrolysis was developed to study the lactonization and hydrolysis of alpha2,8-pentasialic acid. Eleven lactone species of pentasialic acid formed in glacial acetic acid were detected and classified into three groups based on the number of carboxylic acids: monolactones with four carboxylic acids, dilactones with three carboxylic acids, and trilactones with two carboxylic acids. These lactones eluted between the original pentamer (with five carboxylic acids) and the fully lactonized species (with one carboxylic acid) in HPCE. Eight of the isomers were identified by hydrolysis with neuraminodase. Results obtained from previous reports and from this study together reveal a general rule for predicting the subtle difference in the acidity of each carboxylic acid in oligosialic acids: the closer the carboxylic acid is to the nonreducing end, the more acidic it is. Therefore, the elution order of lactone isomers having the same number of carboxylic groups can be predicted from the position of the free carboxylic groups in pentasialic acid. We used this principle and the results of hydrolysis with neuraminidase to identify hexamer lactone isomers separated by HPCE.

Indolicidin, a l3-residue antimicrobial peptide-amide, which is unusually rich in tryptophan and proline, is isolated from the cytoplasmic granules of bovine neutrophils. In this study, the structures of indolicidin in 50% D3-trifluoroethanol and in the absence and presence of SDS and D38-dodecylphosphocholine were determined using NMR spectroscopy. Multiple conformations were found and were shown to be due to different combinations of contact between the two WPW motifs. Although indolicidin is bactericidal and able to permeabilize bacterial membranes, it does not lead to cell wall lysis, showing that there is more than one mechanism of antimicrobial action. The structure of indolicidin in aqueous solution was a globular and amphipathic conformation, differing from the wedge shape adopted in lipid micelles, and these two structures were predicted to have different functions. Indolicidin, which is known to inhibit DNA synthesis and induce filamentation of bacteria, was shown to bind DNA in gel retardation and fluorescence quenching experiments. Further investigations using surface plasmon resonance confirmed the DNA-binding ability and showed the sequence preference of indolicidin. Based on our biophysical studies and previous results, we present a diagram illustrating the DNA-binding mechanism of the antimicrobial action of indolicidin and explaining the roles of the peptide when interacting with lipid bilayers at different concentrations.

Treatment of alpha-NeuAc-(2-->8)-NeuAc (1) with SO3-pyridine (4 equiv) in DMF resulted in selective 9-O-sulfation on the nonreducing end residue and the formation of an inter-residual delta-lactone. The lactonization could result from the C-2 carboxylic acid of the nonreducing residue condensing with the hydroxyl group or/and sulfated group at C-9 of the reducing residue to form a six-membered ring between two adjacent sialic acid residues. When alpha-NeuAc-(2-->9)-NeuAc (5) was used as a sulfation substrate, only 9-O-sulfation on the nonreducing end residue was observed. According to capillary electrophoresis (CE) analysis, 9-O-sulfation on the disialic acid is a fast reaction, while sulfation on other hydroxyl groups is insignificant under the conditions used.

Alpha-(2 --> 8)/alpha(2 --> 9) alternatively linked polysialic acid (PSA) can be identified by controlled hydrolysis followed by the analysis with capillary electrophoresis (CE). Due to the different stability of alpha(2 --> 8) and alpha(2 --> 9) linkages in acidic hydrolysis, oligosialic acids (OSAs) from the hydrolysis of alpha(2 --> 8)/alpha(2 --> 9) OSA/PSA could be classified into two groups in the CE profile. The group with an odd numerical degree of polymerization (DP) had two peaks in the CE profile, and the other group, with even number of DP, showed one peak. Each alternating alpha(2 --> 8)/alpha(2 --> 9) linked OSA contains two isomers: one starts with the alpha(2 --> 8) linkage from the nonreducing end and the other starts with the alpha(2 --> 9) linkage from the nonreducing end. Trimers and tetramers were isolated by using a Mono Q column with an HPLC system. The two trimer isomers are alpha(2 --> 8)/alpha(2 --> 9) and alpha(2 --> 9)/alpha(2 --> 8) linkages and only showed partial separation by CE. After lactonization, sialidase hydrolysis, and alkaline treatment, the two trimer isomers could be separated and identified by CE analysis, but only the alpha(2 --> 8)/alpha(2 --> 9) trimer could be converted to the dilactone in glacial acetic acid. The two tetramer isomers could be converted to four monolactones and three dilactones. These lactonized species could be identified on the basis of several principles in sialidase hydrolysis and lactonization. In conclusion, regioselectivity on the lactonization of oligosialic acids proceeds under several principles: (1) Lactonization takes place more easily in the alpha(2 --> 8) linkage than in the alpha(2 --> 9) linkage; (2) all of the positions of alpha(2 --> 8) linkages in alpha(2 --> 8)/alpha(2 --> 9) alternatively linked OSA can be lactonized regardless of external or internal carboxyl groups involved; and (3) for the site of alpha(2 --> 9) linkage, only internal carboxyl groups can be lactonized.

A facile synthesis of the sialic acid oligomers alpha-(2--5)Neu5Gc (1) is presented. Monosaccharides 2-4 with suitable functionality were used as the building blocks. After selective removal of the paired carboxyl and amine protecting groups, the fully protected oligomers were assembled through consecutive coupling of the building blocks by well established peptide coupling techniques. By this approach, fully protected oligomers as large as an octasaccharide were synthesized. Deprotection of these fully protected oligomers was conducted in two steps (LiCl in refluxing pyridine and 0.1 n NaOH) to afford the desired products in high yield. Enzymatic degradation of the octamer with neuraminidase, monitored by capillary electrophoresis (CE), was also accomplished. The stepwise exo-cleavage adducts were all well separated and identified in the CE spectrum. The strategy described here for solution-phase synthesis also provides the basis for future solid-phase synthesis of poly-alpha-(2--5)Neu5Gc.

The effect of chitin, poly-β-(1→4)- N -acetyl-glucosamine, and chitosan, a polymer of glucosamine obtained by the deacetylation of chitin, on growth and nutrient digestibility was studied in tilapia, Oreochromis niloticus × O. aureus , fed diets containing fiber at 0, 2, 5 or 10% of a basal diet for 8 weeks. Each diet was fed to triplicate groups of fish with a mean initial body weight of 0.99±0.01 g. Significantly ( P r =0.97, P r =0.73, P P

The effect of chitin, poly-beta-(1 --> 4)-N-acetyl-glucosamine, and chitosan, a polymer of glucosamine obtained by the deacetylation of chitin, on growth and nutrient digestibility was studied in grass shrimp, Penaeus monodon. Shrimp were fed for 8 wk diets containing no supplement (control) or 2, 5 or 10 g/100 g chitin or chitosan. Each diet was fed to triplicate groups of shrimp with a mean initial body weight of 0.45 +/- 0.05 g. Significantly higher body weight gains were observed in shrimp fed the 5% chitin diet than in those fed the 10% chitin or the control diet. The weight gain of shrimp decreased as dietary chitosan supplementation level increased (r = 0. 87, P < 0.05). Feed efficiencies (FE) and protein efficiency ratios (PER) followed the same pattern. Lower protein and lipid digestibilities and lower body protein and lipid contents were observed in shrimp fed all chitosan-containing diets than in controls (P < 0.05). Carbohydrate digestibility was lower in shrimp fed the 10% chitosan diet than in those fed the control diet. Lower protein and lipid digestibilities, body lipid content and blood cholesterol concentration were observed in shrimp fed the 10% chitin diet compared with controls (P < 0.05). Higher weight gains, body lipid contents and blood cholesterol concentrations were observed in shrimp fed the 2 and 5% chitin diets than in those fed the chitosan diets. Shrimp fed the 5% chitin diet had higher protein and lipid digestibilities and higher body protein content than those fed the 5% chitosan diet (P < 0.05). These data suggest that dietary chitin, supplemented at 5%, enhances P. monodon growth, whereas chitosan depresses shrimp growth, regardless of the supplementation level.

Pharmacokinetic-pharmacodynamic (PK-PD) modeling was used to characterize the antipyretic and anti-inflammatory effects in rats of Rhein, a major component in rhubarb. Twenty-four healthy male Sprague-Dawley (SD) rats were randomly into four groups, of 6 each. The rats in first group were injected intravenously with lipopolysaccharide (LPS, 100 microg x kg(-1)). The second group rats were given rhubarb decoction (RD, 1.54 g x kg(-1)) by oral administration alone. The rats belonging to third group were administered orally RD 30 min after LPS injection. The rest rats were given normal saline only as control group. Orbital sinus blood sampling was collected at different time points. The Rhein and NO concentration in plasma and body temperature (BT) were measured. Relevant data of PK-PD modeling were performed with Kinetica 5. 0. 11. RD could suppress the rise in BT and plasma NO concentration. The antipyretic and anti-inflammatory responses were best described by a Sigmod-E(max) model. Delay between exposure and response was accounted for by a transit compartment model with two parallel transit compartment chains. The results showed that some parameters such as t1/2, C(max) and AUC were significantly increased in rats treated with LPS, compared to those in rats treated with normal saline. The EC50 for antipyretic effect and decrease of plasma NO concentration was respectively equal to 114.1, 90.80 microg x L(-1). The E(max) for antipyretic effect was about 111% of that for increase in BT after LPS injection. The E(max) for anti-inflammatory action was close to 8.399% of that for elevated NO level after modeling. Meanwhile, there was a difference in pharmacokinetic process of Rhein between the impact of normal saline and LPS. So, it can be concluded that the targets of regulating NO production and BT after RD administration may be at the same location. Not only do that, the antipyretic effect induced by RD maybe completely manifest through reducing the plasma concentration of NO.

An approximate model for the delactonization of tri-sialic acid lactone is presented with two water-layers that led to neutral hydrolysis of δ-lactone. The hydrolytic reactivity was studied with a 10-ns in-solution molecular dynamics simulation. The initial step of this hydrolysis involves a reactant water nucleophile complex via a proton transfer with another water molecule. Therefore, the probability of water molecules localized at the hydrolytic center correlates to the hydrolysis of δ-lactone. The stepwise delactonization of α2,8-(NeuAc) 3 lactone results/resulted from water concentration discrepancy near the carbonyl carbon of lactones in two water oxygen⋯carbonyl carbon shells, and the distances of O C⋯O water layers were 2.8 A and 5.1 A. Based on in-solution molecular dynamics study, the motion of water molecules over the re -face of the carbonyl groups was used for the quantitative description of the residence probability, p , whose value is 0.11 for lactone I and 0.33 for lactone II. The geometric criteria used to determine the residence statistics are (1) the distance of water–oxygen⋯carbonyl carbon in less than 5.1 A and (2) the cone angle, θ , of carbonyl O C⋯O water in the range of 85–115°. As expected, a higher residence probability at lactone II led to its faster hydrolysis. Both the radial g( r ) and angular p( θ ) pair distribution functions of water oxygen and carbonyl groups of lactones ensure a better surrounding hydration encounter for lactone II. In contrast, water molecules around lactone I are deduced due to a steric hindrance by the turn structure of α2,8-(NeuAc) 3 lactone.

Four iridium(III)-containing coordination polymers 1-4 using Ir(ppy)(2)(H(2)dcbpy)PF(6) (L-H(2), ppy = 2-phenylpyridine, H(2)dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) as the bridging ligand, [ZnL(2)]·3DMF·5H(2)O (1), [CdL(2)(H(2)O)(2)]·3DMF·6H(2)O (2), [CoL(2)(H(2)O)(2)]·2DMF·8H(2)O (3) and [NiL(2)(H(2)O)(2)]·3DMF·6H(2)O (4), have been synthesized and structurally characterized. The emissions from 1-4 are ascribed to a metal-to-ligand charge transfer transition (MLCT). The absolute emission quantum yields for 1-4 in single crystals were measured in air to be 0.274, 0.193, 0.001 and 0.002, respectively. The noteworthy oxygen-sensing properties of 1-4 as well as L-H(2) in a single crystal were also evaluated. The Stern-Volmer quenching constant, K(SV) values, of 1-4 and L-H(2) can be deduced to be 0.834, 2.820, 1.328, 1.111 and 2.476, respectively. The results show promising K(SV) values (e.g.2) that are competitive or even larger than those of many known Ir-complexes. Moreover, the short response time (e.g. compound 2) and recovery times toward oxygen of 1-4 have been measured in their single crystal forms. The reversibility experiments for 1-4 were carried out for seven repeated cycles. As a result,75% recovery of intensity for 1 and 2 on each cycle demonstrates a high degree of reproducibility during the sensing process. It should be noted that iridium(III)-containing coordination polymers with high emission intensity and notable oxygen sensing properties are obscure, especially in the single crystal form. This, in combination with its fine reversibility, leads to success in single crystal oxygen recognition based on photoluminescence imaging. The detection limit could be 0.50% for gaseous oxygen. Moreover, the temperature effect of compound 2 in a single crystal upon application as an oxygen sensor was expected.

Because of rapid alterations in lifestyle and the incidence of metabolic syndrome (MetS), the prevalence of carotid atherosclerosis (CA) and carotid plaque (CP) may increase in China. We aimed to evaluate the prevalence of CA and CP as well as its relation to MetS in an East Chinese population.The study included 6142 subjects who underwent general health screening including carotid ultrasonography in 2009. Diagnoses of MetS were made according to the revised Adult Treatment Panel III criteria.The prevalence of CA and CP increased gradually with age. These conditions were more prevalent in men than in women (CA: 22.1%vs 12.0%, P0.001; CP: 12.6%vs 7.2%, P0.001). Multivariate logistic regression analysis showed that male gender, age, blood pressure, fasting blood glucose (FBG) and low-density lipoprotein cholesterol were risk factors for CA and CP, while high-density lipoprotein cholesterol was protective for CA. Age ≥ 50 years has the largest impact on CA and CP, followed by elevated blood pressure and elevated blood glucose. Individuals with MetS had a higher prevalence of CA (27.7%vs 20.0% in men, 24.0%vs 10.3% in women; P0.001 in both) and CP (16.6%vs 11.2% in men, P0.001; 11.8%vs 6.5% in women, P0.005) than those without MetS. The prevalence and odds ratios of CA and CP aggregated with an increasing number of MetS components, even in individuals exhibiting only one component.These results indicate that CA and CP have become a major public health problem in China. MetS and its components were associated with an increased prevalence of CA and CP.

To determine the molecular defects of beta-thalassemia intermedia in Guangdong Province and to provide basis for gene diagnosis and gene therapy of this disorder.DNA analysis of the alpha, beta and gamma globin genes was performed in 18 children with beta-thalassemia intermedia from Guangdong Province using polymerase chain reaction (PCR), microarray technique, Southern blot and direct sequencing.Of the 18 patients,one was identified as the homozygote of TATA box-28 (A--G) change, one as the homozygote of betaE26 (G--A) mutation, ten as compound heterozygotes of TATA box- 28 (A--G) mutation with other beta-globin mutations, two as compound heterozygotes of betaE26 (G--A ) mutation with other beta globin mutations, and four as double heterozygotes for beta globin and alpha globin mutations including -SEA and -alpha(4.2).The molecular defects of beta- thalassemia intermedia in Guangdong Province were highly heterogeneous and its spectrum was different from the reports from other provinces of China.

The new technology of genechip is exerting a significant impact on the identification of thalassemia, and allows to rapidly and efficiently detect a number of molecular disorders. The aim of the present study was to explore the application value of the diagnostic genechip in determining thalassemia.The subjects group consisted of 62 children with alpha thalassemia and 93 children with beta thalassemia (60 with thalassemia trait, 33 with thalassemia major) from Guangdong province were tested from July 2002 to July 2003; 115 were males and 40 were females, the age ranged from 1 day to 11 years. These children had mild, moderate or severe anemia. Laboratory examinations showed microcytosis and hypochromocytosis. DNA was extracted from ACD coagulated blood with Invisorb DNA extraction kit. After preparation, the alpha and beta globin gene organization and structure of sample was analyzed by genechip technology.(1) Heterozygotes, homozygotes and compound heterozygotes of the three commonest deletional alpha thalassemia (--(SEA), -alpha(3.7), -alpha(4.2)) and two non-deletional alpha thalassemia (HbCS, HbQS) were successfully detected. (2) Eight different mutations were identified in 126 chromosomes among 60 cases with beta thalassemia traits and 33 cases with beta thalassemia major, namely CD41-42, IVS-II-654, TATAbox-28, CD17, CD71-72 (+A), betaE(26) CD27-28 (+C) and CD71-72 (+T), with the frequencies of 33.5%, 23.9%, 15.0%, 15.0%, 4.8%, 2.4%, 2.4% and 1.5% respectively. (3) Eight cases (13.3%) in 60 thalassemia traits, two cases (6%) 33 cases with thalassemia major were detected to be combined with alpha thalassemia mutation.(1) The usage of genechip in identifying thalassemia mutations has the advantages of simplicity, economy and shorter time. This technique does not use radioisotope and could also detect alpha and beta thalassemia mutations simultaneously. (2) The occurrence of alpha and beta thalassemia dual heterozygotes is frequent in Guangdong province and the genechip technology is important in genetic counseling and prenatal diagnosis of thalassemia in this area.

Alpha-(2 --8)/alpha(2 --9) alternatively linked polysialic acid (PSA) can be identified by controlled hydrolysis followed by the analysis with capillary electrophoresis (CE). Due to the different stability of alpha(2 --8) and alpha(2 --9) linkages in acidic hydrolysis, oligosialic acids (OSAs) from the hydrolysis of alpha(2 --8)/alpha(2 --9) OSA/PSA could be classified into two groups in the CE profile. The group with an odd numerical degree of polymerization (DP) had two peaks in the CE profile, and the other group, with even number of DP, showed one peak. Each alternating alpha(2 --8)/alpha(2 --9) linked OSA contains two isomers: one starts with the alpha(2 --8) linkage from the nonreducing end and the other starts with the alpha(2 --9) linkage from the nonreducing end. Trimers and tetramers were isolated by using a Mono Q column with an HPLC system. The two trimer isomers are alpha(2 --8)/alpha(2 --9) and alpha(2 --9)/alpha(2 --8) linkages and only showed partial separation by CE. After lactonization, sialidase hydrolysis, and alkaline treatment, the two trimer isomers could be separated and identified by CE analysis, but only the alpha(2 --8)/alpha(2 --9) trimer could be converted to the dilactone in glacial acetic acid. The two tetramer isomers could be converted to four monolactones and three dilactones. These lactonized species could be identified on the basis of several principles in sialidase hydrolysis and lactonization. In conclusion, regioselectivity on the lactonization of oligosialic acids proceeds under several principles: (1) Lactonization takes place more easily in the alpha(2 --8) linkage than in the alpha(2 --9) linkage; (2) all of the positions of alpha(2 --8) linkages in alpha(2 --8)/alpha(2 --9) alternatively linked OSA can be lactonized regardless of external or internal carboxyl groups involved; and (3) for the site of alpha(2 --9) linkage, only internal carboxyl groups can be lactonized.

Among the three chiral columns, CHIROBIOTIC T, CHIRLPAK WH, and CHIRALCEL OD-R, tested for the separation of racemic amino acids and N-acetyl-amino acids, only CHIROBIOTIC T chiral column which is based on covalently bonded amphoteric glycopeptide, teicoplanin, as the stationary phase ligand could be successfully developed to enantiomerically separate racemic amino acids and N-acetyl amino acids simultaneously. This method can be used to determine the enantiomeric composition of amino acids and N-acetyl-amino acids in the catalysis of D-aminoacylase or L-aminoacylase and the conversion rate of N-acylamino acid racemases.

In this article, a photochromic dye, 3-bromo-2,2-dimethyl-2H-pyrano[3,2-c]chromen-5-one in its closed form (DDPC-CF), was coated with four different shapes of silver nanoparticles: nanospheres (AgS), nanoprisms (AgP), nanowires (AgW), and nanodisks (AgD), respectively. The resulting films, AgS-DDPC-CF, AgP-DDPC-CF, AgW-DDPC-CF, and AgD-DDPC-CF, have been fabricated on glass. Upon irradiation with UV light at various irradiation wavelengths, AgS-DDPC-CF, AgP-DDPC-CF, AgW-DDPC-CF, and AgD-DDPC-CF underwent a ring opening reaction to produce the opened forms AgS-DDPC-OF, AgP-DDPC-OF, AgW-DDPC-OF and AgD-DDPC-OF, respectively. It is found that the excitation of localized surface plasmons between the silver nanoparticles–silver nanoparticles could enhance the photochromic reaction efficiency in comparison with that of DDPC alone. The enhancement factor (E) and the volume percentages of the enhanced areas (FE) in the entire shell of the forward photochromic reaction of AgS-DDPC to AgD-DDPC depending on the irradiation wavelength can be deduced to be 1–12 (30–65%), 1–2 (30–55%), 1–23 (50–70%), and 2–30 (55–70%), respectively. The E factor (and FE) of the recovery photochromic reaction of AgP-DDPC and AgD-DDPC on glass can be deduced to be 20 (68%) and 3 (51%). The results show promising photochromic reaction efficiency values (e.g.AgP-DDPC and AgD-DDPC) that are enhanced greatly by the silver nanoparticles. Furthermore, the kinetics of AgS-DDPC to AgD-DDPC upon irradiation demonstrated here implies an acceleration of the photochromic reaction due to excitation of localized surface plasmons. AgP-DDPC and AgD-DDPC have a good photochromic reversibility during the photoinduced forward and reverse processes. Such a switching process of AgP-DDPC and AgD-DDPC can proceed for at least 10 cycles. The results should exemplify a model to investigate the photophysical properties of relevant chromenes in the solid state, especially their photochromic properties with improved conversion performance and the associated applications.

The cover picture shows the simulated NMR spectroscopic structure of polysialic acid polylactone. The local turn conformation of this right-handed helix is held by an interresidual C–H···O hydrogen bond. The seams connected by C–H···O hydrogen bonds support the cooperative acid-catalyzed lactonization of oligosialic acid. The hydrogen bond can be seen as the detonator of a Chinese firecracker. Once the hydrogen bond is formed (just like the ignition of the detonator), the cooperative lactones are formed stepwise in the polysialic acid. The construction of the right-handed helix was described in a previous article (Eur. J. Org. Chem.2007, 3648). The observation of the C–H···O hydrogen bond is presented in the article by C.-S. Chen et al. on p. 3351 ff. The authors thank Ms. Jui-Wen Sue for the photograph in the cover picture.