Towards the automation of vulnerability detection in source code

Software vulnerability detection, which involves security property specification and verification, is essential in assuring the software security. However, the process of vulnerability detection is labor-intensive, time-consuming and error-prone if done manually. In this thesis, we present a hybrid approach, which utilizes the power of static and dynamic analysis for performing vulnerability detection in a systematic way. The key contributions of this thesis are threefold. first, a vulnerability detection framework, which supports security property specification, potential vulnerability detection, and dynamic verification, is proposed. Second, an investigation of test data generation for dynamic verification is conducted. Third, the concept of reducing security property verification to reachability is introduced

N′-(2,4-Dichloro­benzyl­idene)-2-fluoro­benzohydrazide

The mol­ecule of the title compound, C14H9Cl2FN2O, exists in a trans configuration with respect to the methyl­idene unit and the benzene rings form a dihedral angle of 8.1 (2)°. In the crystal, mol­ecules are linked through N—H⋯O hydrogen bonds into C(4) chains propagating in [100]

Geometry and optics calibration of WFCTA prototype telescopes using star light

The Large High Altitude Air Shower Observatory project is proposed to study high energy gamma ray astronomy ( 40 GeV-1 PeV ) and cosmic ray physics ( 20 TeV-1 EeV ). The wide field of view Cherenkov telescope array, as a component of the LHAASO project, will be used to study energy spectrum and compositions of cosmic ray by measuring the total Cherenkov light generated by air showers and shower maximum depth. Two prototype telescopes have been in operation since 2008. The pointing accuracy of each telescope is crucial to the direction reconstruction of the primary particles. On the other hand the primary energy reconstruction relies on the shape of the Cherenkov image on the camera and the unrecorded photons due to the imperfect connections between photomultiplier tubes. UV bright stars are used as point-like objects to calibrate the pointing and to study the optical properties of the camera, the spot size and the fractions of unrecorded photons in the insensitive areas of the camera.Comment: 5 pages, 6 figures, submitted to Chinese Physics

Yield enhancement of recombinant α-Amylases in Bacillus amyloliquefaciens by ARTP mutagenesis-screening and medium optimization

α-Amylase is the most extensively applied enzyme in industry. There is an urgent need for improvement on the yield of α-amylases currently. Herein, a strategy which combined Atmospheric and Room Temperature Plasma (ARTP) mutagenesis tool for construction of mutant library of Bacillus amyloliquefaciens with a 24-well plates screening technique was adopted to improve the yield of recombinant Bacillus amyloliquefaciens α-amylases (BAA). A mutant strain named B. amyloliquefaciens ZN mut-7# was obtained, and the activity of BAA produced by this mutant strain was 86.92% higher than that of the original strain. B. amyloliquefaciens ZN mut-7# has an unchanged BAA gene and genetic stability. This successful application proved that ARTP can be applied to the genetically engineering strains that contain recombinant plasmid. Furthermore, response surface methodology offers an achievable and efficient strategy to optimize the composition of medium used to generate BAA in B. amyloliquefaciens ZN mut-7#. A 1.28-fold increase had been obtained compared to the production of non-optimized fermentation medium. This study demonstrates that ARTP mutagenesis and medium optimization are efficient and feasible methods for increasing recombinant enzyme production in the genetically engineering strains

Two New Glycosides from Sanicula lamelligera

Two new glycosides, 21-O-β -D-glucopyranosyl-olean-12-ene-3β , 16α, 21β , 22α, 28-pentol

[2-(2-Chloro­phen­yl)-2-hy­droxy­eth­yl](isoprop­yl)ammonium 4-hy­droxy­benzoate

The title molecular salt, C11H17ClNO+·C7H5O3 −, was obtained by the reaction of racemic clorprenaline and 4-hy­droxy­benzoic acid. In the crystal, the components are connected by O—H⋯O and N—H⋯O hydrogen bonds, resulting in a two-dimensional hydrogen-bonded network

Four Phragmalin Orthoesters from the Chinese Mangrove Xylocarpus granatum

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A Peptide That Binds Specifically to the β-Amyloid of Alzheimer's Disease: Selection and Assessment of Anti-β-Amyloid Neurotoxic Effects

The accumulation of the amyloid-β peptide (Aβ) into amyloid plaques, an essential event in Alzheimer's disease (AD) pathogenesis, has caused researchers to seek compounds that physiologically bind Aβ and modulate its aggregation and neurotoxicity. In order to develop new Aβ-specific peptides for AD, a randomized 12-mer peptide library with Aβ1-10 as the target was used to identify peptides in the present study. After three rounds of selection, specific phages were screened, and their binding affinities to Aβ1-10 were found to be highly specific. Finally, a special peptide was synthesized according to the sequences of the selected phages. In addition, the effects of the special peptide on Aβ aggregation and Aβ-mediated neurotoxicity in vitro and in vivo were assessed. The results show that the special peptide not only inhibited the aggregation of Aβ into plaques, but it also alleviated Aβ-induced PC12 cell viability and apoptosis at appropriate concentrations as assessed by the cell counting kit-8 assay and propidium iodide staining. Moreover, the special peptide exhibited a protective effect against Aβ-induced learning and memory deficits in rats, as determined by the Morris water maze task. In conclusion, we selected a peptide that specifically binds Aβ1-10 and can modulate Aβ aggregation and Aβ-induced neuronal damage. This opens up possibilities for the development of a novel therapeutic approach for the treatment of AD

Atherosclerosis and Helminths Infection

Atherosclerosis is a chronic disease that causes various cardiovascular complications. Plaque formation in atherosclerosis is considered similar to the pathogenesis of other autoimmune diseases; thus, immunomodulation and immunosuppression may present strategies for the treatment and prevention of these diseases. Interestingly helminth infection was found to inhibit T helper 1-mediated autoimmune diseases and T helper 2-mediated allergy and asthma, indicating significant potential for clinical application. Some study even found that therapeutic efficacy of the viable tapeworm was superior to dexamethasone treatment. Recently, some studies have shown an inverse association between helminth infections and inflammatory diseases, including diabetes mellitus, lipid abnormality, and atherosclerosis. Will the underlying mechanism bring us a new idea on the treatment for these diseases? We tried to find an answer by reviewing recent articles