Enhancing detection coverage in untargeted metabolomics analysis by solid-phase extraction on-line coupled to LC-MS/MS.

Buffer overflow is one of the most critical software vulnerabilities with numerous functional and security impacts on memory boundaries and program calls. An exploitable buffer overflow, which can be directly or indirectly triggered through external user domain inputs, is of a greater concern because it can be misused during run-time for adversarial intention. Although some existing tools offer buffer overflow detection to certain extents, there are major limitations, such as, poor detection coverage and ad-hoc/manual verification efforts due to inadequate predefined executions for static analysis and substantially large input subspace for dynamic verification. In this paper, to provide program verification in static time with high detection coverage, we propose an automated framework for Exploitable Buffer Overflow Detection by Information Flow Tracking (BOFT). We achieve this goal following three steps - first, BOFT analyzes the usage of arrays, pointers, and vulnerable application programming interface (APIs) in the program code and automatically inserts assertions required for buffer overflow detection. Second, BOFT instruments the program with taints for direct and indirect information flow tracking using an extensive set of formal expressions. Finally, it symbolically analyzes the instrumented code for maximum coverage and provides the list of exploitable buffer overflow vulnerabilities. BOFT is evaluated on standard benchmarks from SAMATE Juliet Test Suite (NIST) with a successful detection of ~94.87% (minimum) of exploitable buffer overflows with zero false positives.

Sorbent, device, matrix and application in microextraction by packed sorbent (MEPS): A review.

An enrichment step in a sample treatment is essential for trace analysis to improve the sensitivity and to eliminate the matrix of the sample. Solid-phase extraction (SPE) is one of the widely used enrichment technique. Electrothermal atomic absorption spectrometry (ETAAS) is a well-established determination technique for trace elements. The integration of SPE with ETAAS leads to further improvement of sensitivity, an automation of the measurement and the economy in the sample size, amounts of the reagents and time for the sample pretreatment. The integration is achieved by introducing the solid phase used for the enrichment directly into ETAAS for a batch method, or on-line coupling of a SPE column with ETAAS. Fine particles of various materials, including an activated carbon, an ion-exchange resin, a cellulose nitrate resin and biomass materials were used as adsorbents for batch method. A membrane filter was also used. A simultaneous multi-elements extraction and a speciation analysis were accomplished. A microcolumn packed with resin beads or an open tubular column such as a PTFE tube or a silica capillary tube having the chemically modified inner wall were used for the on-line coupling.

Solid-phase extraction: method development, sorbents, and coupling with liquid chromatography

The coverage of Toddler Stimulation Detection and Early Developmental Intervention (SDIDTK) at the Talang Banjar Health Center in Jambi City in 2020 was still far from the target set by the Jambi City Health Office and was the lowest coverage in Jambi City. However, scope of program implementation reached 51%. This study aim to evaluate the management implementation of the Stimulation of Detection and Early Intervention for Toddler Growth and Development (SDIDTK) at the Talang Banjar Health Center. This research was a qualitative study. Data collected from juni-august 2022, by in-depth interviews, observation and document review. In-depth interviews were conducted with 8 informants consisting of public health center employees and mothers with toddlers. In the understanding input component of Permenkes number 66 of 2016 was still lacking, there were staff program who have never received training, the number of available facilities and infrastructure was uncompleted. The components of the process of planning, organizing, workshops, supervision and evaluation, recording and reporting have been going well. Health services running by the program was unoptimal. Coverage has not been achieved because the implementation of SDIDTK for toddlers at the Talang Banjar Health Center has not been optimal.
 Keywords: Stimulation, Early Detection, Toddler, Public Health Center

The identification and quantification of cereal storage proteins is of interest of many researchers. Their structural or functional properties are usually affected by the way how they are extracted. The efficiency of extraction process depends on the cereal source and working conditions. Here, we described various commonly used extraction protocols differing in the extraction conditions (pre-extraction of albumins/globulins, sequential extraction of individual protein fractions or co-extraction of gluten proteins, heating or non-heating, reducing or non-reducing conditions). The total protein content of all fractions extracted from commercially available wheat and rye flours was measured by the Bradford method. Tris-Tricine SDS-PAGE was used to determine the molecular weights of wheat gliadins, rye secalins and high-molecular weight glutelins which are the main triggering factors causing celiac disease. Moreover, we were able to distinguish individual subunits (α/β-, γ-, ω-gliadins and 40k-γ-, 75k-γ-, ω-secalins) of wheat/rye prolamins. Generally, modified extraction protocols against classical Osborne procedure were more effective and yields higher protein content in all protein fractions. Bradford measurement led into underestimation of results in three extraction procedures, while all protein fractions were clearly identified on SDS-PAGE gels. Co-extraction of gluten proteins resulted in appearance of both, low-molecular weight fractions (wheat gliadins and rye secalins) as well as high-molecular weight glutelins which means that is not necessary to extract gluten proteins separately. The two of three extraction protocols showed high technical reproducibility with coefficient of variation less than 20%. Carefully optimized extraction protocol can be advantageous for further analyses of cereal prolamins.

Energetic gas-phase particles that collide with adsorbed species on solid surfaces induce a variety of processes. Collision induced processes (CIP) are important and may play a central role in the mechanism governing heterogeneous catalytic reactions at high pressures and elevated temperatures. A number of different CIPs are discussed in this article with a strong emphasis on the utilization of molecular dynamics (MD) simulations as a tool for gaining molecular level mechanistic and dynamic insight into chemical events under investigation. Collision induced desorption (CID) is the simplest CIP to be discussed. The CID of N2 from Ru(001) is described as a test case for the effect of collisions on a polarized adsorbate and has been studied at both low and high coverages. The interpretation of the experimental data at low coverage using MD simulations has led to the introduction of a new desorption mechanism. It involves strong coupling of surface corrugation and adsorbate frustrated rotation that lead to a normal motion away from the surface. Another system for which CID was shown to provide unique information is that of water on Ru(001). Here, the enhanced CID rate was demonstrated to be selective for a specific adsorption site/structure on the surface (the A2 site), providing a new insight into the structure of water on this surface, recently recalculated by employing ab initio methods. At the multilayer coverage range, a remarkable stability was found of the ice layer against CID, suggesting particularly efficient dissipation of the collider energy within the hydrogen bonded network at an ice thickness of 3 bilayers and above. A unique CIP to be discussed is collision induced migration (CIM), a new phenomenon that has never been considered before. Based on MD simulations, it is shown that CIM may result in migration distances of more than 150 Å at very low coverage, whereas at high coverage, these displacements are shortened significantly. The potential importance of this process for inducing novel catalytic routes on surfaces is discussed. A related example involves MD simulations that address the relation between tracer surface diffusion and the pressure of collider from the gas phase. It is predicted that by increasing the pressure in the range 0−500 atm significant changes in adsorbates surface diffusivity should take place as a result of collision induced migration. Finally, CID within the O2/Ag(110) system arising from photodissociation of adsorbed molecular oxygen is described. MD simulations were used to explain the experimentally determined coverage dependent phenomena such as desorption yield and angular distribution of desorbates.

A novel anion-exchange resin containing three amine groups was prepared by reaction of a chloromethylated polystyrene-divinylbenzene (PS-DVB) resin with diethylenetriamine. After being protonated by contact with an aqueous acid, this resin can be used for ion chromatographic separation of anions. The charge on the resins can be varied from +1 to +3 by changing the mobile phase pH. The selectivity of the new ion exchangers for various inorganic anions was quite different from that of conventional anion exchangers. The performance of this new anion exchanger was studied by changing the pH and the concentration of the eluent, and several different eluents were used with some common anions as testing analytes. Conductivity detection and UV-visible detection were applied to detect the anions after separation. The new resin can also be used for HPLC separation of neutral organic compounds. Alkylphenols and alkylbenzenes were separated with this new polymeric resin, and excellent separations were obtained under simple conditions. This report contains Chapter 1: General introduction and Chapter 6: General conclusions.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolute retention mechanism in semipermeable surface chromatographyHong Qi. Wang, Carla. Desilets, and Fred E. RegnierCite this: Anal. Chem. 1992, 64, 22, 2821–2825Publication Date (Print):November 15, 1992Publication History Published online1 May 2002Published inissue 15 November 1992https://pubs.acs.org/doi/10.1021/ac00046a027https://doi.org/10.1021/ac00046a027research-articleACS PublicationsRequest reuse permissionsArticle Views55Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Analyst Coverage and the Glamour Discount

Significance and backgroundGliadin is known to trigger the celiac disease or gluten sensitivity affecting around 70 million people globally. Its detection in early stages has become a controversial issue due to lack of efficient gliadin extraction procedures. The efficiency of gliadin extraction procedure is therefore an important critical step to the results of detection of gluten‐derived products from either rapid immunoreactivity assay kit or analytical mass analysis. Hence, four gliadin extraction procedures were investigated using six wheat cultivars and analyzed for their physiochemical analysis.FindingsThe relative proportion of ω‐gliadin, α/β‐, γ‐gliadin, HMW‐NG, and amino acid concentration of gliadin varied with the extraction protocol. The higher proportion of α/β‐, γ‐gliadin was found in Weiss extraction protocol (79.74%–88.62%) and lowest in Wallace (50.70%–58.91%). The ω‐gliadin was found to be significantly (p ≤ .05) highest in DuPont (9.78%–22.54%) and lowest in Weiss protocol (0.46%–1.04%). The region between 36 and 44 kDa showed well‐resolved bands in DuPont, while a dense mass in other extraction protocols. Amino acid score was found to be significantly (p ≤ .05) higher in DuPont (79.53–91.75 g/100 g), followed by Osborne (67.17–81.16 g/100 g), Wallace (68.54–77.58 g/100 g), and Weiss (60.97–79.16 g/100 g) extracted gliadin.ConclusionThe extraction protocol was found to influence the proportion of different protein fractions as well as amino acid concentration.Significance and noveltyThe insight obtained gives a better understanding of how the same protein behaves when extracted with different extraction protocols.

Results of a retrospective database analysis of adherence to statin therapy and risk of nonfatal ischemic heart disease in daily clinical practice in Italy

Theoretical study of Sn adsorbed on the Au(1 1 1) surface

: Semi-empirical calculations were performed for small clusters modelling the adsorption of CO on nickel (100), (110), and (111) surfaces at low and high coverage levels and on nickel-copper alloy (100) surfaces at low coverage. The bearing of the results upon the understanding of experimentally observed faceting and magnetization (Hedvall) effects is discussed. A preference for adsorption at multifold sites is observed at low coverage, and the (100) and (111) surfaces are predicted to be energetically smooth at high coverages. The results for alloy surfaces are qualitatively in agreement with experiment. (Author)

The determination of particle collision kinetics is useful to decouple the effects of process parameters on individual events in flocculation. This paper discusses the effects of flocculation conditions on the collision efficiency of ATCC strain CRL 1606 hybridomas flocculated with poly-L-histidine. Experimental determinations of the collision efficiency of cells in Couette flow are presented over a range of experimental conditions. The collision efficiency correlates with the cell zeta potential to the -2.4 power at high surface coverage, consistent with literature results in latex systems. At low coverage, accounting for the distribution of polymer on the cells corrects for deviation from the high-coverage behavior. Collision is dependent on the hydrodynamic environment as well. At high surface coverage, collision efficiency is weakly dependent on hydrodynamic conditions and follows a dependency on the shear rate and viscosity to the -0.32 power. This is consistent with ionic coagulation theory. At low surface coverage, the collision efficiency is strongly dependent on the viscous fluid forces. The results versus both dose and shear rate over the entire range of surface coverages are consistent with weak intercell bonding. Collision kinetics in the presence of high molecular weight dextrans show steric hindrance to cell collision.