Apigenin suppresses epithelial-mesenchymal transition in high glucose-induced retinal pigment epithelial cell by inhibiting CBP/p300-mediated histone acetylation.

Epithelial mesenchymal transition (EMT) is a critical process implicated in the pathogenesis of retinal fibrosis and the exacerbation of diabetic retinopathy (DR) within retinal pigment epithelium (RPE) cells. Apigenin (AP), a potential dietary supplement for managing diabetes and its associated complications, has demonstrated inhibitory effects on EMT in various diseases. However, the specific impact and underlying mechanisms of AP on EMT in RPE cells remain poorly understood. In this study, we have successfully validated the inhibitory effects of AP on high glucose-induced EMT in ARPE-19 cells and diabetic db/db mice. Notably, our findings have identified CBP/p300 as a potential therapeutic target for EMT in RPE cells and have further substantiated that AP effectively downregulates the expression of EMT-related genes by attenuating the activity of CBP/p300, consequently reducing histone acetylation alterations within the promoter region of these genes. Taken together, our results provide novel evidence supporting the inhibitory effect of AP on EMT in RPE cells, and highlight the potential of specifically targeting CBP/p300 as a strategy for inhibiting retinal fibrosis in the context of DR.

Experimental evidence of ß-relaxation and its structural origin in ZIF-62 glass.

Intrinsic relaxation processes determine the crucial properties of glass, yet their underlying mechanisms are far from well understood. The brand-new glass-forming metal-organic frameworks (MOFs) provide desirable opportunities for looking inside glass relaxation, especially the secondary ß-relaxation phenomenon and mechanism. For a representative zeolitic imidazolate framework-62 (ZIF-62) glass, reliable and fine powder mechanical spectroscopy was performed based on home-made mountings combined with a commercial dynamical mechanical analyzer. For the first time, ß-relaxation was observed in a MOF glass besides the primary α-relaxation. The pronounced ß-relaxation was well demonstrated by a number of characteristics including an excess wing and the full width at half maximum (W) of the α-relaxation peaks, which deviated from the time-temperature superposition. The stretched exponent ß of ZIF-62 glass is 0.71 in the supercooled region. The W of ZIF-62 glass is the maximum among all known glassy materials. The structural origin of α- and ß-relaxation can be attributed to an increase of density, as observed using nuclear magnetic resonance (NMR). A general linear and broad correlation of fragility and stretched exponent ß with W of the α-relaxation peaks was established. When compared with traditional glass-formers, the resulting principles indicate a shared origin for the stretched exponent ß, W, and ß-relaxation in the case of ZIF-62 glass. The presented findings offer an effective new method to explore the glass/liquid transition of MOF glasses, which helps to obtain a deeper insight into the hierarchical relaxation dynamics of the glass transition.

[Research and application of intelligent hyperspectral analysis technology for Chinese materia medica].

With the development of imaging technology and artificial intelligence, hyperspectral imaging technology provides a fast, non-destructive, intelligent, and precise new method for the analysis of Chinese materia medica(CMM). This paper summarized the methods and applications of hyperspectral imaging technology combined with intelligent analysis technology in the field of CMM in recent years, focusing on the acquisition and preprocessing of hyperspectral data, intelligent analysis methods of hyperspectral data, and practical cases of these technologies in the field of CMM. Hyperspectral data of CMM can provide spectral information with nanometer-level resolution and rich spatial texture information simultaneously. This paper summarized the acquisition process, including black-and-white board calibration and region-of-interest extraction, and preprocessing methods including smoothing, differentiation, scale-space, and scattering correction. The feature extraction methods in terms of spectral, spatial, color, and texture were briefly described, and common modeling methods were summarized. Finally, this paper reviewed the research cases of the application of the above methods to the fields of CMM, such as authenticity identification, origin tracing, variety recognition, year identification, sulfur fumigation degree determination, and quantitative measurement.

De Novo Design of a Highly Selective Nonpeptide Fluorogenic Probe for Chymotrypsin Activity Sensing in a Living System.

Chymotrypsin, an extensively known proteolytic enzyme, plays a substantial role in maintaining physiological functions, including protein digestion, immune response, and tissue repair. To date, intense attention has been focused on the invention of efficient and sensitive chemical tools for chymotrypsin activity measurement. Among them, the "nonpeptide"-based chymotrypsin probe design strategy utilizing the esterase activity of chymotrypsin has been well-developed due to its low cost and high atom-economy feature. However, the ester-bond-based nature of these probes make them possibly vulnerable to esterases and active chemicals. These defects strictly restricted the application of the previously reported probes, especially for imaging in living systems. Therefore, to acquire fluorogenic probes with sufficient stability and specificity for chymotrypsin sensing in a complicated biological environment, a more stable skeleton for nonpeptide-based chymotrypsin probe construction is urgently needed. Herein, a novel nonpeptide-based fluorogenic probe for specific chymotrypsin activity sensing was designed and synthesized by the substitution of an ester-based linker with a heptafluorobutylamide moiety. The acquired probe, named TMBIHF, showed high selectivity toward various enzymes and reactive chemicals, while it retained high sensitivity and catalytic efficiency toward chymotrypsin. Moreover, TMBIHF was successfully applied for monitoring chymotrypsin activity and pancreas development in live zebrafish, specific sensing of exogenous and endogenous chymotrypsin in nude mice, and visualizing chymotrypsin-like activity-dependent cellular apoptosis, thus providing an alternative and reliable way for chymotrypsin-targeted biosensor or prodrug construction.

Pyroglutamate Aminopeptidase I Promotes Hepatocellular Carcinoma via IL-6/STAT3 Activation as Revealed by a Specific Biosensor.

As a global health challenge, hepatocellular carcinoma (HCC) is strongly associated with chronic inflammation. Targeting inflammation, particularly inflammatory factors, is regarded as an important strategy for HCC diagnosis and treatment. Pyroglutamic aminopeptidase I (PGP-I), a common exopeptidase, was recently identified as a novel inflammatory cytokine in cells. However, whether PGP-I is involved in HCC development and can be regarded as a biomarker remains unclear. To address this issue, endogenous PGP-I was imaged in live cells and in vivo, and the related biochemical and pathological processes were analyzed accordingly with a newly developed fluorogenic PGP-I biosensor. Bioimaging with the specific biosensor demonstrated the aberrant expression of PGP-I in HCC cell lines and tumor-bearing nude mice. Moreover, overexpression of PGP-I in HCC cells promoted tumor progression, whereas knockdown of PGP-I significantly suppressed tumor cell growth and migration. The activity of PGP-I was further identified to be highly related to the phosphorylation of STAT3, which could be impeded by the natural product parthenolide. Collectively, these findings suggest that PGP-I, which can promote hepatocellular tumor progression through the classical inflammation-/tumor-related IL-6/STAT3 pathway, may serve as a potential HCC biomarker and therapeutic target.

Multienzyme-Targeted Fluorescent Probe as a Biosensing Platform for Broad Detection of Pesticide Residues.

Pesticide residues, significantly hampering the overall environmental and human health, have become an increasingly severe issue. Thus, developing rapid, cost-effective, and sensitive tools for monitoring the pesticide residues in food and water is extremely important. Compared to the conventional and chromatographic techniques, enzyme inhibition-based biosensors conjugated with the fluorogenic probes provide effective alternative methods for detecting pesticide residues due to the inherent advantages including high selectivity and sensitivity, simple operation, and capability of providing in situ and real-time information. However, the detection efficiency of a single enzyme-targeted biosensor in practical samples is strongly impeded by the structural diversity of pesticides and their distinct targets. In this work, we developed a strategy of multienzyme-targeted fluorescent probe design and accordingly obtained a novel fluorescent probe (named as 3CP) for detecting the presence of wide variety of pesticides. The designed probe 3CP, targeting cholinesterases, carboxylesterases, and chymotrypsin simultaneously, yielded intense fluorescence in the solid state upon the enzyme-catalyzed hydrolysis. It showed excellent sensitivity against organophosphorus and carbamate pesticides, and the detection limit for dichlorvos achieved 1.14 pg/L. Moreover, it allowed for the diffusion-resistant in situ visualization of pesticides in live cells and zebrafish and the sensitive measurement of organophosphorus pesticides in fresh vegetables, demonstrating the promising potential for tracking the pesticide residues in environment and biological systems.

An Activity-Based Fluorogenic Probe Enables Cellular and in Vivo Profiling of Carboxylesterase Isozymes.

Carboxylesterases (CEs) exist as multiple types of isomers in humans, and two major types are CE1 and CE2. They are widely distributed in human tissues and well-known for their important roles in drug metabolism and pathology of various diseases. Thus, the detection of CEs in living systems could provide efficient proof in disease diagnostics, as well as important information regarding chemotherapeutic effects of antitumor drugs and prognosis. To develop a specific probe to discriminate CEs from other hydrolases, especially cholinesterases, is quite challenging due to their structural similarities and substrate specificity. To date, almost all of the fluorescent probes developed for CEs have been constructed with an acetyl group as the recognition unit. Herein we proposed a new design strategy of probe-cavity matching, which led to the identification of a new fluorogenic substrate (termed as HBT-CE) with high specificity toward both CE isomers and improved sensitivity, considering the higher binding affinity and catalysis efficiency. The promising capability of HBT-CE was further demonstrated for endogenous CEs imaging in living cells, zebrafish, and nude mice. In addition, HBT-CE was successfully applied in kinetically monitoring drug-induced CE regulation in cancer cells. All of these findings suggest that HBT-CE is a valuable tool for tracking and imaging endogenous CEs in complex biological systems.

Organic/metal interface-modulated magnetism in [Fe/C60]3 multilayers and Fe-C60 composites.

Because of the expected long spin-transport length of organic materials, the magnetic metal/organic interface is crucial to the application of organic spintronics. In this study, [Fe/C60]3 multilayers were fabricated for the investigation of C60-mediated magnetic interlayer coupling. [Fe/C60]3 thin films were characterized using the magneto-optical Kerr effect, transmission electron microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS). The thin films revealed in-plane magnetic anisotropy, and the magnetic coercivity (H c ) drastically decreased from 6-8 mT to 0.5 mT with the increase of C60 thickness from 0.1 nm to 5 nm. The insertion of the C60 layer considerably reduced H c because a thickness greater than 1 nm of the C60 layer is sufficient for blocking magnetic exchange coupling between Fe layers. In addition, post-annealing increased H c because of Fe inter-diffusion, which promotes magnetic exchange coupling and further Fe-C bonding, as confirmed by a comparative study of XPS C-spectra. The thermally triggered inter-diffusion between Fe and C60 layers turned the multilayers into a mixed composite film and thus caused magnetic variation. Annealing time and temperature can be used as control parameters for the tuning of magnetism in Fe-C60 composites.

Tumour necrosis factor-α-induced protein 8-like 2 is a novel regulator of proliferation, migration, and invasion in human rectal adenocarcinoma cells.

Tumour necrosis factor-α-induced protein 8-like 2 (TIPE2) is a tumour suppressor in many types of cancer. However, the mechanism of action of TIPE2 on the growth of rectal adenocarcinoma is unknown. Our results showed that the expression levels of TIPE2 in human rectal adenocarcinoma tissues were higher than those in adjacent non-tumour tissues. Overexpression of TIPE2 reduced the proliferation, migration, and invasion of human rectal adenocarcinoma cells and down-regulation of TIPE2 showed reverse effects. TIPE2 overexpression increased apoptosis through down-regulating the expression levels of Wnt3a, phospho (p)-ß-Catenin, and p-glycogen synthase kinase-3ß in rectal adenocarcinoma cells, however, TIPE2 knockdown exhibited reverse trends. TIPE2 overexpression decreased autophagy by reducing the expression levels of p-Smad2, p-Smad3, and transforming growth factor-beta (TGF-ß) in rectal adenocarcinoma cells, however, TIPE2 knockdown showed opposite effects. Furthermore, TIPE2 overexpression reduced the growth of xenografted human rectal adenocarcinoma, whereas TIPE2 knockdown promoted the growth of rectal adenocarcinoma tumours by modulating angiogenesis. In conclusion, TIPE2 could regulate the proliferation, migration, and invasion of human rectal adenocarcinoma cells through Wnt/ß-Catenin and TGF-ß/Smad2/3 signalling pathways. TIPE2 is a potential therapeutic target for the treatment of rectal adenocarcinoma.

Activity-Based Near-Infrared Fluorogenic Probe for Enabling in Vitro and in Vivo Profiling of Neutrophil Elastase.

Neutrophil elastase (NE), a typical hematopoietic serine protease, has significant roles in inflammatory and immune responses, and thus is highly associated with various diseases such as acute lung injury (ALI) and lung cancer. Rapid and accurate measurement of NE activity in biological systems is particularly important for understanding the role of NE in inflammatory diseases, as well as clinical diagnosis. However, the specific detection and noninvasive imaging of NE in vivo remains a challenge. To address this issue, a small-molecule substrate based near-infrared fluorogenic probe (NEP) for NE was constructed via incorporating pentafluoroethyl as the recognition group with a hemicyanine dye-based fluorophore. This initially quenched probe possesses more than 25-fold red fluorescence enhancement upon the catalysis of human NE, and the detection limit is about 29.6 ng/mL. In addition, the high specificity and the long emission wavelength (λemmax = 700 nm) of NEP allowed the direct monitoring of NE-trafficking, exogenous NE uptake, and endogenous NE upregulation at the cellular level. Moreover, the successful spatiotemporal imaging of NE in ALI model mice also made it a promising new tool in clinical diagnosis for ALI and other lung diseases.

Effectiveness and safety of chemotherapy with cytokine-induced killer cells in non-small cell lung cancer: A systematic review and meta-analysis of 32 randomized controlled trials.

BACKGROUND AIMS: Cytokine-induced killer (CIK) cells are the most commonly used cellular immunotherapy for multiple tumors. To further confirm whether chemotherapy with CIK cells improves clinical effectiveness and to reveal its optimal use in non-small cell lung cancer (NSCLC), we systematically reevaluated all relevant studies. METHODS: We collected all studies about chemotherapy with CIK cells for NSCLC from the Medline, Embase, Web of Science, China National Knowledge Infrastructure Database (CNKI), Chinese Scientific Journals Full-Text Database (VIP), Wanfang Data, China Biological Medicine Database (CBM), Cochrane Central Register of Controlled Trials (CENTRAL), Chinese clinical trial registry (Chi-CTR), World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and U.S. clinical trials. We evaluated their quality according to the Cochrane evaluation handbook of randomized controlled trials (RCTs) (version 5.1.0), extracted the data using a standard data extraction form, synthesized the data using meta-analysis and finally rated the evidence quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: Thirty-two RCTs with 2250 patients were included, and most trials had unclear risk of bias. The merged risk ratios values and their 95% confidence intervals of meta-analysis for objective response rate, disease control rate, 1- and 2-year overall survival rates, 1- and 2-year progression-free survival rates were as following: 1.45 (1.31-1.61), 1.26 (1.16-.37), 1.42 (1.23-1.63), 2.06 (1.36-3.12), 1.93 (1.38-2.69) and 3.30 (1.13-9.67). Compared with chemotherapy alone, all differences were statistically significant. CIK cells could increase the CD3+ T cells, CD3+ CD4+ T cells, NK cells and the ratio of CD4+/CD8+ T cells. The chemotherapy with CIK cells had a lower risk of hematotoxicity, gastrointestinal toxicity, liver injury and a higher fever than that of chemotherapy alone. The evidence quality was "moderate" to "very low." CONCLUSIONS: The available moderate evidences indicate that chemotherapy with CIK cells, especially autologous CIK cells, can significantly improve the tumor responses, 1- and 2-year overall and progression-free survival rates in patients with advanced NSCLC. This treatment does have a high risk of fever. The optimal use may be treatment with one or two cycles and in combination with vinorelbine and cisplatin, paclitaxel and cisplatin, or docetaxel and cisplatin.

PEST-containing nuclear protein mediates the proliferation, migration, and invasion of human neuroblastoma cells through MAPK and PI3K/AKT/mTOR signaling pathways.

BACKGROUND: PEST-containing nuclear protein (PCNP), a novel nuclear protein, is involved in cell proliferation and tumorigenesis. However, the precise mechanism of action of PCNP in the process of tumor growth has not yet been fully elucidated. METHODS: ShRNA knockdown and overexpression of PCNP were performed in human neuroblastoma cells. Tumorigenic and metastatic effects of PCNP were examined by tumor growth, migration, and invasion assays in vitro, as well as xenograft tumor assay in vivo. RESULTS: PCNP over-expression decreased the proliferation, migration, and invasion of human neuroblastoma cells and down-regulation of PCNP showed reverse effects. PCNP over-expression increased protein expressions of cleaved caspase-3, cleaved caspase-8, cleaved caspase-9, and cleaved poly adenosine diphosphate-ribose polymerase, as well as ratios of B-cell lymphoma-2 (Bcl-2)-associated X protein/Bcl-2 and Bcl-2-associated death promoter/B-cell lymphoma-extra large in human neuroblastoma cells, however PCNP knockdown exhibited reverse trends. PCNP over-expression increased phosphorylations of extracellular signal-regulated protein kinase 1/2, p38, c-Jun N-terminal kinase, as well as decreased phosphorylations of phosphatidylinositol 3-kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR), nevertheless PCNP knockdown exhibited opposite effects. Furthermore, PCNP over-expression significantly reduced the growth of human neuroblastoma xenograft tumors by down-regulating angiogenesis, whereas PCNP knockdown markedly promoted the growth of human neuroblastoma xenograft tumors through up-regulation of angiogenesis. CONCLUSIONS: PCNP mediates the proliferation, migration, and invasion of human neuroblastoma cells through mitogen-activated protein kinase and PI3K/AKT/mTOR signaling pathways, implying that PCNP is a therapeutic target for patients with neuroblastoma.

Three-dimensional display with directional beam splitter array.

Multi-view three-dimensional (3-D) displays using directional beam splitter array were proposed to achieve a perfect 3-D perception with low cross-talk. The multi-direction collimated light may project different images to different viewing zones to form the multi-view autostereoscopic display. Furthermore, a high resolution 3-D display can be realized with a sequential beam splitter array and a sequential liquid crystal display. By optimization, the cross-talk of the directional beam splitter backlight system was lowered to 5% to improve the perception of the 3-D displays.

Compositional phase diagram and microscopic mechanism of Ba1-xCaxZryTi1-yO3 relaxor ferroelectrics.

With extensive first-principles density-functional calculations, we construct a three-dimensional compositional phase diagram of Ba1-xCaxZryTi1-yO3 (BCZT) with the Ca and Zr content in the ranges of 0 ≤ xCa ≤ 0.2 and 0 ≤ yZr ≤ 1. Our calculations show that, when the Zr content increases, the difference in energy and difference in the structural parameters of the cubic, tetragonal, orthorhombic, and rhombohedral phases of BCZT are reduced. Eventually, all four phases merge into a multiphase with coexisting cubic structures (MPCCS) under Zr-rich conditions, indicating that BCZT undergoes phase transition from a normal ferroelectric (NFE) to a relaxor ferroelectric (RFE), consistent with experimental observations. The 3D diagram shows that the regions of merged and separated energy surfaces correspond to the regions of the RFE and NFE, respectively, which suggests that a MPCCS corresponds to a RFE. In addition, with the MPCCS model and Landau-Devonshire theory, we provide an interpretation of the high electromechanical properties of the BCZT relaxor ferroelectric and apply it to the classical local random field and micro-macro domain transition models.

[Effect of compound Longmaining decoction with different combinations on intestinal absorption of puerarin].

To study the effects of compound Longmaining(FFLMN) with different combinations on the intestinal absorption of puerarin. The rat single pass intestinal perfusion model was adopted, and the concentration of puerarin in intestinal samples was determined by HPLC. The effects of different combination groups on the absorption of puerarin in duodenum, jejunum, ileum and colon were investigated. The combined drugs were GG(Puerariae Lobatae Radix), GG-CSL (Puerariae Lobatae Radix compared with Dioscoreae Nipponicae Rhizoma), GG-CX(Puerariae Lobatae Radix compared with Chuanxiong Rhizoma) and FFLMN (compound Longmaining). We found that the absorption rate constant(Ka) and the apparent coefficient(Papp) of puerarin had no significant difference between GG-CSL and FFLMN groups, but significantly higher in GG and GG-CX groups(P<0.05) in the duodenum and ileum. In jejunum and colon, Ka and Papp of puerarin showed significant differences between GG and other groups(P<0.05). At the same time, FFLMN also had significant differences with GG-CSL and GG-CX groups(P<0.05). The results showed that in the whole intestine of rats, FFLMN could significantly promote the absorption of puerarin. In the duodenum and ileum, Dioscoreae Nipponicae Rhizoma played a significant role in promoting absorption of puerarin. In jejunum and colon, Dioscoreae Nipponicae Rhizoma and Chuanxiong Rhizoma have a synergistic effect in promoting absorption of puerarin.

Effects of occlusion on mandibular morphology and architecture in rats.

BACKGROUND: A rodent occlusal hypofunction model has been widely established in jawbone-related studies. However, the effects of occlusal stimuli, with total elimination of molar contacts, and its rehabilitation on mandibular remodeling remain unclear. MATERIALS AND METHODS: Forty-eight 5-wk-old Sprague-Dawley male rats were used. Twenty-four experimental rats underwent occlusal hypofunction by insertion of a bite-raising appliance. Twenty-four rats received no treatment (control group). Two weeks later, half the experimental rats (occlusal hypofunction group) were killed; the appliance was removed from the remaining experimental rats (recovery group) for two additional weeks before killing. Control animals were killed biweekly. Body weight and masseter muscle weight were measured, and the mandibles were subjected to micro-computed tomography to evaluate the mandibular morphology and cortical bone characteristics. The expressions of osteoblast- and osteoclast-related genes were evaluated with quantitative polymerase chain reaction. RESULTS: No significant body weight differences were observed between the experimental and control rats. However, lighter masseter muscle, shorter mandibular incisor crown, mandibular body and ramus, and higher mandibular alveolar process and first molar fossae were observed in the occlusal hypofunction group. Moreover, the cortical bone characteristics associated with the expression of osteoblast- and osteoclast-related genes were remarkably different in the central and posterior mandible in the occlusal hypofunction group. At the 2-wk recovery time point after occlusal stimuli, the altered parameters in the masseter and mandible returned to normal levels. CONCLUSIONS: Mandibular remodeling via bone turnover is region specific for altered occlusal stimuli. Normal occlusion is an important determinant of the mandibular morphology and architecture.

[Effect of puerarin in Longmaining formula on pharmacokinetics-pharmacodynamics correlation in rats with myocardial ischemia].

To study the pharmacokinetics of puerarin in compound Longmaining(FFLMN) in normal rats and myocardial ischemia rats, and investigate its correlation with anti-myocardial ischemia effect of FFLMN. Models of myocardial ischemia rats were produced by subcutaneous injection of isoproterenol(ISO), then FFLMN extract solution was administered by gavage. Orbital sinus blood sampling was collected at different time points after gavage. HPLC-UV method was applied to determine the concentration of puerarin in plasma, and compare the difference in pharmacokinetics between normal rats and model rats after application of same dose of FFLMN. Meanwhile, microplate reader was used to determine IL-6 and SOD activities in plasma of different time points, and draw dose-effect curve. The results indicated that the pharmacokinetics of puerarin conformed to the two-compartment model in both normal group and myocardial ischemia model group. In the comparison of main pharmacokinetic parameters between two groups: AUC0-∞=(11.451±3.228) mg•h•L⁻¹,AUC0-t=(14.047±3.765) mg•h•L⁻¹, Cmax=(5.623±1.40) mg•L⁻¹ in normal group; AUC0-∞=(68.849±50.396 9) mg•h•L⁻¹, AUC0-t= (58.312±45.802) mg•h•L⁻¹,Cmax=(18.456±7.517) mg•L⁻¹ in treatment group. The SOD level was significantly increased and IL-6 concentration was significantly decreased in plasma, indicating that as compared with the normal group, puerarin in FFLMN had a higher plasma concentration, slower elimination rate and higher bioavailability. Therefore, puerarin concentration in plasma has correlation with the anti-myocardial ischemia effect of FFLMN, which could increase SOD level and inhibit the release of IL-6.

Construction of a directional T vector for cloning PCR products and expression in Escherichia coli.

In order to clone PCR products and express them effectively in Escherichia coli, a directional cloning system was constructed by generating a T vector based on pQE-30Xa. The vector was prepared by inserting an XcmI cassette containing an endonuclease XcmI site, a kanamycin selective marker, a multiple-cloning-site (MCS) region and an opposite endonuclease XcmI site into the vector pQE-30Xa. The T vector pQE-T with single overhanging dT residues at both 3' ends was obtained by digesting with the restriction enzyme XcmI. For directional cloning, a BamHI site was introduced to the ends of the PCR products. A BamHI site was also located on the multiple cloning site of pQE-T. The PCR products were ligated with pQE-T. The directionally inserted recombinants were distinguished by using BamHI to digest the recombinants because there are two BamHI sites located on the both sides of PCR fragment. In order to identify the T-vector functions, the 14-3-3-ZsGreen and hRBP genes were amplified and a BamHI site was added to the ends of the genes to confirm this vector by ligation with pQE-T. Results showed that the 14-3-3-ZsGreen and hRBP were cloned to the vector pQE-T directly and corresponding proteins were successfully produced. It was here demonstrated that this directional vector is capable of gene cloning and is used to manipulate gene expression very easily. The methodology proposed here involves easy incorporation of the construct into other vectors in various hosts.

Ab initio atomistic thermodynamics study on the oxidation mechanism of binary and ternary alloy surfaces.

Utilizing a combination of ab initio density-functional theory and thermodynamics formalism, we have established the microscopic mechanisms for oxidation of the binary and ternary alloy surfaces and provided a clear explanation for the experimental results of the oxidation. We construct three-dimensional surface phase diagrams (SPDs) for oxygen adsorption on three different Nb-X(110) (X = Ti, Al or Si) binary alloy surfaces. On the basis of the obtained SPDs, we conclude a general microscopic mechanism for the thermodynamic oxidation, that is, under O-rich conditions, a uniform single-phase SPD (type I) and a nonuniform double-phase SPD (type II) correspond to the sustained complete selective oxidation and the non-sustained partial selective oxidation by adding the X element, respectively. Furthermore, by revealing the framework of thermodynamics for the oxidation mechanism of ternary alloys through the comparison of the surface energies of two separated binary alloys, we provide an understanding for the selective oxidation behavior of the Nb ternary alloy surfaces. Using these general microscopic mechanisms, one could predict the oxidation behavior of any binary and multi-component alloy surfaces based on thermodynamics considerations.