Target Preparation Research Articles

Diagnostic test accuracy of an automated device for the MALDI target preparation for microbial identification

The objective of this study was to evaluate the performance of the Copan Colibrí™ against the manual preparation of the MALDI targets. We analyzed 416 (31 different species) non-duplicate strains covering the most important species identified in clinical routine. We also assessed the intra-strain repeatability between the comparable methods. We then analyzed the performance of this new method after implementation in routine on 12,253 aerobic bacterial isolates and yeasts, encompassing a total of 42 different species. Among the 416 strains analyzed, 6.3% (26/416) and 10.8% (45/416) had a score value < 2 when processed by the Colibri™ and manual method, respectively. Only 5.9% (9/152) of the Gram positive rods and cocci had a score values < 2 by the Colibri™ versus 20.4% (31/152) by the manual method. We confirmed that this relative superiority observed for the Colibri™ was due primarily in the use of the formic acid protocol. For the Gram-negative bacteria, the results of both methods were comparable; 6.6% (17/256) and 4.7% (12/256) had a score value < 2 by the Colibri™ and the manual method, respectively. After implementation in routine, the results according to the Biotyper score cut-off values were distributed as follows: < 1.70: 2.5% (304/12,253), 1.70–1.79: 1.9% (227/12,253), 1.80–1.89: 3.1% (377/12,253), 1.90–1.99: 6.7% (825/12,253), and ≥ 2: 85.9% (10,520/12,253). The Colibrí™ coupled to MALDI-TOF/MS revealed good performances and higher intra-strain repeatability as compared to the manual preparation of the MALDI targets.

Study on the Densification of Osmium by Experiment and First Principle Calculations.

The sintering of osmium is critical for the preparation of raw material targets for film coating, which is the main application area of osmium. In order to get a better understanding of the intrinsic mechanism of densification of osmium, a serial study on the sintering behavior of osmium has been made in this study. By the master sintering curve (MSC) and constant heating rate (CHR) method, the sintering activation energy of nanosized osmium is evaluated to be about 340 kJ/mol, which is higher than most other metals. The density-functional theory calculation indicates the higher energy barrier of the surface atom and vacancy migration and lacking migration tunnel of inner point vacancies. For example, the diffusion of osmium atoms on the surface of particles is mainly limited by Os (1010), which has an energy barrier as high as 1.14 eV, that is higher than the W atom on W (110) of 0.99 eV. The vacancy migration energy barrier inside osmium's grains is higher than 3.0 eV, while that of W is only 1.7 eV. This means that it is more difficult for osmium to achieve a high density compared with W, which is consistent with the experimental results. Accordingly, the proposed strategy provides a new opportunity to design a sintering process for target fabrication with excellent properties for various applications.

Preparation of Actinide Targets at Oregon State University

Preparation of Actinide Targets at Oregon State University

IMPLEMENTASI MANAJEMEN PEMBELAJARAN TAHFIDZUL QURAN DI MI MUHAMMADIYAH KARANGWUNI POLOKARTO

The results of the study show that: (1) Tahfidzul Quran learning planning is done through the preparation of memorization targets and the determination of effective weeks and days in each semester; (2) Organizing is carried out through the division of tasks and responsibilities as well as the construction of the structure of the tutoring teacher; (3) The mobilization is carried out through the coordination meeting of the Tahfidz coordinator as a shering forum for decision making and direction of the Tahfidzul Quran learning program and the implementation of learning is carried out every Monday-Friday; and (4) Supervision is carried out through assessing teacher performance at the end of December and June. The highest achievement target for the second year of the implementation of the Tahfidzul Quran's 2017/2018 year program is juz 29 and 30, the lowest target for class 1 is juz 30 to Surat al Ghasyiyyah. For class 1, 85% of the target is achieved and 11% of students exceed the target. Class 2 targets reached 19%. Class 3, 10.86% reached the target and 035% of students exceeded the target. Class 4 tarjet reached 12.44%. Class 5 targets reached 4.24%, and the last grade 6 target reached 13.79% and 1.5% of students exceeded the target.

Target preparation of low-pressure cold-sprayed metal powder coatings to create defined micro-leakage

Abstract Defined micro-leaks have been used as reference leaks in non-destructive testing for many years, for example in the adjustment, calibration and functional testing of helium leak detectors. Test leaks are also used in non-destructive testing training to teach the staff how to detect these “invisible” leaks. The traditional production of test specimens with defined leakage, however, is timecon suming and expensive. In addition, these specimens are susceptible to impacts and can break easily. A new approach for producing robust specimens with defined leakage is gas dynamic cold spraying, or cold spraying, where a very small opening is closed using an open-pore metal powder filling. This manufacturing process is particularly suitable for industrial purposes due to the good controllability of the production process. Unlike traditionally manufactured glass bodies, the specimens produced in this way are less susceptible to mechanical impacts. The present study is concerned with the metallographic examination of porous coatings to create defined leaks using cold spraying.

Hydrogen isotope ratio measurement by AMS at CIAE

Knowledge of the ratio of hydrogen isotopes contributes to many research fields. We have developed an accelerator mass spectrometry (AMS) method allowing simultaneous measurement of D/H and T/H ratios. We present a novel TiH2 sample preparation method suitable for the preparation of AMS targets and we describe the measurement technique developed with our in-house 300 kV AMS system at CIAE. We achieved a H+ transmission efficiency of 65 % and T/H measurement background of 2 × 10−15. Measurement of isotopic standard samples gave linear relationships between the measured and nominal values for both T/H and D/H.

Redox-Controlled Chemical Protein Synthesis: Sundry Shades of Latency.

ConspectusThe last two decades have witnessed the rise in power of chemical protein synthesis to the point where it now constitutes an established corpus of synthetic methods efficiently complementing biological approaches. One factor explaining this spectacular evolution is the emergence of a new class of chemoselective reactions enabling the formation of native peptide bonds between two unprotected peptidic segments, also known as native ligation reactions. In recent years, their application has fueled the production of homogeneous batches of large and highly decorated protein targets with a control of their composition at the atomic level. In doing so, native ligation reactions have provided the means for successful applications in chemical biology, medicinal chemistry, materials science, and nanotechnology research.The native chemical ligation (NCL) reaction has had a major impact on the field by enabling the chemoselective formation of a native peptide bond between a C-terminal peptidyl thioester and an N-terminal cysteinyl peptide. Since its introduction in 1994, the NCL reaction has been made the object of significant improvements and its scope and limitations have been thoroughly investigated. Furthermore, the diversification of peptide segment assembly strategies has been essential to access proteins of increasing complexity and has had to overcome the challenge of controlling the reactivity of ligation partners.One hallmark of NCL is its dependency on thiol reactivity, including for its catalysis. While Nature constantly plays with the redox properties of biological thiols for the regulation of numerous biochemical pathways, such a control of reactivity is challenging to achieve in synthetic organic chemistry and, in particular, for those methods used for assembling peptide segments by chemical ligation. This Account covers the studies conducted by our group in this area. A leading theme of our research has been the conception of controllable acyl donors and cysteine surrogates that place the chemoselective formation of amide bonds by NCL-like reactions under the control of dichalcogenide-based redox systems. The dependency of the redox potential of dichalcogenide bonds on the nature of the chalcogenides involved (S, Se) has appeared as a powerful means for diversifying the systems, while allowing their sequential activation for protein synthesis. Such a control of reactivity mediated by the addition of harmless redox additives has greatly facilitated the modular and efficient preparation of multiple targets of biological relevance. Taken together, these endeavors provide a practical and robust set of methods to address synthetic challenges in chemical protein synthesis.

STRATEGI BRANDING DAN KONSEP PUBLIKASI BERBASIS LOCAL TOURISM DI ERA 4.0 (Studi kasus media sosial dan peran Desain Komunikasi visual)

Branding is introducing an image of both services and physical products, the process taken must have a strategy and preparation of measurable time targets. There are many ways to introduce a product, which is the current trend of the 4.0 era where most transactions and information are traded in the IoT-based world. Local tourism has now developed, by utilizing the potential of the surrounding nature and then being developed as the basis for the products offered, improvements are made in various sectors to support the display to boost publications, of course with a communication angle. The need for researchers to take steps to dissect the flow in building a publication concept in the form of a realistic road map with applied strategies and analysis combined with good publication management is the core of the research carried out. The design thinking method is applied to dissect what strategic steps will be used in determining the core of the publication with impact factors. Local tourism branding and publication strategies are influenced by engagement from the psychological model of one touch flayer of social media users related to the happynest side factor that affects the pattern of attractive content with a high response rate and saddnes side factor which is empathetic with a low response rate.

Upgrade of the HIVIPP Deposition Apparatus for Nuclear Physics Thin Targets Manufacturing

The High Energy Vibrational Powder Plating (HIVIPP) technique allows for the preparation of targets starting from refractory metal powders with negligible material losses during the process, thus preserving the expensive isotope-enriched materials. An upgraded HIVIPP apparatus was developed at the Legnaro National Laboratory of the National Institute of Nuclear Physics (INFN-LNL), and it is reported in this work. Particular attention was paid to the design of the sample holder, the automation of the power supply, and the control of the process, all with the aim of obtaining a versatile and reliable apparatus. Several tests have been carried out and the related results are reported proving the flexibility of the apparatus and the process reproducibility. The main result is a ‘ready to use’ technology at INFN-LNL for the preparation of isotopically enriched refractory metal targets that cannot be manufactured using standard techniques.

Correlative Site-Specific Sample Preparation for Atom Probe Tomography on Complex Microstructures.

Site-specific specimen preparation for atom probe tomography (APT) is a challenging task. Small features need to be located using a suitable imaging technique and captured within a volume of less than 0.01 μm3. Correlative microscopy has shown to be helpful for target preparation as well as to gain complementary information about the material. Current strategies developed in that direction can be highly time-consuming and not always ensure the correct site extraction in complex microstructures. In this work, we present a methodology to study grain boundaries and interfaces in martensitic steels by combining electron backscattered diffraction, transmission Kikuchi diffraction (TKD), and APT. Furthermore, we include the design of a sample holder that allows to perform TKD and scanning transmission electron microscopy on the specimen during preparation without breaking the vacuum of the scanning electron microscope/focused ion beam workstation. We show a case study where a prior austenite grain boundary is traced from the bulk material to the apex of the APT specimen. The presence of contamination due to the specimen exposure to the electron beam and the use of plasma cleaning to minimize it are discussed.

DOCKSTRING: Easy Molecular Docking Yields Better Benchmarks for Ligand Design.

The field of machine learning for drug discovery is witnessing an explosion of novel methods. These methods are often benchmarked on simple physicochemical properties such as solubility or general druglikeness, which can be readily computed. However, these properties are poor representatives of objective functions in drug design, mainly because they do not depend on the candidate compound’s interaction with the target. By contrast, molecular docking is a widely applied method in drug discovery to estimate binding affinities. However, docking studies require a significant amount of domain knowledge to set up correctly, which hampers adoption. Here, we present dockstring, a bundle for meaningful and robust comparison of ML models using docking scores. dockstring consists of three components: (1) an open-source Python package for straightforward computation of docking scores, (2) an extensive dataset of docking scores and poses of more than 260,000 molecules for 58 medically relevant targets, and (3) a set of pharmaceutically relevant benchmark tasks such as virtual screening or de novo design of selective kinase inhibitors. The Python package implements a robust ligand and target preparation protocol that allows nonexperts to obtain meaningful docking scores. Our dataset is the first to include docking poses, as well as the first of its size that is a full matrix, thus facilitating experiments in multiobjective optimization and transfer learning. Overall, our results indicate that docking scores are a more realistic evaluation objective than simple physicochemical properties, yielding benchmark tasks that are more challenging and more closely related to real problems in drug discovery.

Tubeimoside-1: A review of its antitumor effects, pharmacokinetics, toxicity, and targeting preparations.

Tubeimoside-1 (TBMS-1), a natural triterpenoid saponin found in traditional Chinese herbal medicine Bolbostemmatis Rhizoma, is present in numerous Chinese medicine preparations. This review aims to comprehensively describe the pharmacology, pharmacokinetics, toxicity and targeting preparations of TBMS-1, as well the therapeutic potential for cancer treatement. Information concerning TBMS-1 was systematically collected from the authoritative internet database of PubMed, Web of Science, and China National Knowledge Infrastructure applying a combination of keywords involving “tumor,” “pharmacokinetics,” “toxicology,” and targeting preparations. New evidence shows that TBMS-1 possesses a remarkable inhibitory effect on the tumors of the respiratory system, digestive system, nervous system, genital system as well as other systems in vivo and in vitro. Pharmacokinetic studies reveal that TBMS-1 is extensively distributed in various tissues and prone to degradation by the gastrointestinal tract after oral administration, causing a decrease in bioavailability. Meanwhile, several lines of evidence have shown that TBMS-1 may cause adverse and toxic effects at high doses. The development of liver-targeting and lung-targeting preparations can reduce the toxic effect of TBMS-1 and increase its efficacy. In summary, TBMS-1 can effectively control tumor treatment. However, additional research is necessary to investigate in vivo antitumor effects and the pharmacokinetics of TBMS-1. In addition, to reduce the toxicity of TBMS-1, future research should aim to modify its structure, formulate targeting preparations or combinations with other drugs.

ANALISIS FAKTOR- FAKTOR YANG BERPENGARUH TERHADAP REALISASI PENDAPATAN ASLI DAERAH

The purpose of this study is to find answers to determine the effectiveness of advertisement tax and the contribution of advertisement tax to local revenue, where in the era of regional autonomy, local governments are required to always increase their regional revenues, such as increasing local tax revenues through billboard tax revenues. Tax revenue through advertising billboards in the city of Batam provides an undeniable contribution to regional revenue. However, in practice it has not yet come close to its true potential, besides that the preparation of this tax target is only based on previous years' experience. The length of this research was conducted from April to July 2018. The object of this research is Batam City Dispenda. The sampling technique used is non-probability sampling, namely the sampling technique using certain considerations or purposive sampling using financial reports from 2017 to 2021. The results of hypothesis testing using the multiple regression analysis method show that simultaneously the effectiveness of advertisement tax and the contribution of advertisement tax has a significant effect on local revenue. While partially the effectiveness of advertisement tax has a significant relationship to local revenue, however, the contribution of advertisement tax has a significant effect on local revenue at the Batam City Dispenda.

Validation of the Colibrí Instrument for Automated Preparation of MALDI-TOF MS Targets for Yeast Identification.

ABSTRACTRecently, Copan (Italy) introduced the Colibrí instrument for automated colony picking and preparation of matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) target plates. Our study aimed to validate this system for yeasts as such testing has not been performed yet and is a missing link needed to implement the system for routine use. Fifty-five Candida strains were selected to evaluate the accuracy of Colibrí. For each strain, a sheep blood agar plate supplemented with X and V factors (HEM) and a Sabouraud agar plate (SAB) were inoculated and incubated using the WASPlab specimen processing system (Copan). After 18 h and 36 h of incubation, the isolates were spotted in parallel using Colibrí and manually onto MALDI-TOF target plates with the addition of formic acid and identified using MALDI-TOF mass spectrometry. The reproducibility was evaluated using ATCC reference and clinical isolate-derived strains. The cumulative percentage of acceptable identification scores (IDs) after 36 h was 91% for strains cultured on HEM plates using both Colibrí and the manual method. The SAB plates showed inferior results for both Colibrí (76%) and the manual method (78%). We observed an overall agreement of 92% at 18 h for identification of the strains on the HEM plates between Colibrí and the manual method and 94% after 36 h. For the SAB plates, the agreement was 78% after 18 h and 84% after 36 h. Apart from Candida dubliniensis and Candida tropicalis, all Candida species were identified with 100% accuracy using Colibrí on HEM plates. We observed good agreement between Colibrí and the manual reference method. These results demonstrate that Colibrí is a reliable system for MALDI-TOF target preparation for yeast identification, allowing increased standardization and less hands-on time.

Nanosecond laser ablation threshold of liquid tin microdroplets

The laser ablation threshold is an important parameter that governs the response of materials to intense laser irradiation. Here we study the ablation threshold of liquid tin, by irradiating tin microdroplets with nanosecond laser pulses having finely controlled temporal shape and duration. We use the time-dependent reflection from the droplet as the main observable, which exhibits a sharp decrease in magnitude at a given time instance that depends on the laser intensity. This moment marks the generation of a plasma that strongly absorbs the following incident laser light, rapidly expands, and thereby sets in motion the remainder of the liquid droplet. We find an inverse-square dependence of this plasma-onset time on laser intensity and attribute this scaling to the presence of one-dimensional heat diffusion during irradiation. This scaling and its one-dimensional thermal origin is strongly established in literature and follows from a square-root scaling of the thermal diffusion depth with time. Our experiment unambiguously shows that this scaling law holds for our specific case of nanosecond laser impact on tin microdroplets. The results presented in this work are of particular interest to target preparation and metrology in extreme-ultraviolet sources utilizing tin microdroplet targets.

Theragnostic 64Cu/67Cu Radioisotopes Production With RFT-30 Cyclotron.

64Cu and 67Cu are theragnostic pair radionuclides with promising application in the nuclear medicine. 64Cu is PET nuclide for the non-invasive diagnosis and 67Cu is beta emitter for therapy of various cancers. This study discusses optimization efforts in the production of these radioactive coppers carried out with 30 MeV cyclotron. Optimized conditions include target preparation, chemical separation, and quality control. The production routes of 64Cu and 67Cu were studied based on the nuclear reactions of 64Ni(p,n)64Cu and 70Zn(p,α)67Cu. The produced 64Cu and 67Cu have >99.9% of the radionuclidic purity. The yield at the end of bombardment (EOB) of 64Cu and 67Cu is 28.5 MBq/μAh and 67Cu is 0.58 MBq/μAh, respectively.

Electrochemical co-deposition of Ni–Gd2O3 for composite thin targets preparation: Production of 155Tb as a case study

In the last years, 155Tb has attracted enormous interest due to its potential role in theranostics in nuclear medicine. To estimate its production yield, the aim of this study was to develop a method to prepare thin Gd-enriched-containing targets aimed at the 155Gd(d, 2n)155Tb nuclear cross section measurement. To this end, the electrochemical co-deposition method has been chosen to manufacture Ni–Gd2O3 composite targets. Several process parameters that have an impact on the deposit quality, have been investigated to increase the incorporation of Gd mass (up to 3 mg). To validate the concept, seven targets made by natural Gd were irradiated with deuteron beams at the GIP ARRONAX facility cyclotron, with an energy range ranging from 8 MeV to 30 MeV to extract the cross section values by using the stacked-foils method. Results obtained turned out to have great consistency with existing published data thus validating the proposed method. Therefore, an alternative target manufacturing concept aimed at cross section measurement is presented in this work.

IDENTIFICATION OF NEW POTENTIAL SARS-COV-2 PROTEINS INHIBITORS THROUGH VIRTUAL SCREENING AND MOLECULAR DOCKING SIMULATIONS

The pathogen Coronavirus is a member of the Orthocoronavirinae subfamily of the Coronaviridae family and the Nidovirales order. Four structural proteins, in addition to viral RNA and Nsp1-16, are employed to speed up virus replication within host cells. Antiviral drugs that target the S protein have recently been discovered, although the technique of targeting the S protein has some limitations. The objective of the study was to test the potential inhibitors for the use of novel agents against CoV-2 infection. In this, we conducted the virtual screening of various lead compounds from three different databases i.e. SWEETLEAD, ZINC, and Selleckchem Antiviral compound library against COVID-19 proteins Nsp 15 and Nsp 7 and 8 complex which act as receptors using two software like Molegro Virtual Docker and PyRx. For this, a phytochemical library was constructed followed by ligand and target preparation. The molecular docking and Virtual screening as well as ADMET characteristics were also analyzed. Our results revealed twenty high-affinity lead compounds from 4,200 molecules out of which Danoprevir, Lanatoside C, and Digoxin/ZINC242548690 can act as powerful inhibitors of Nsp 15 and Lanatoside C, Ledipasvir, and BMS-790052 for Nsp 7 and 8 complex targets respectively.

Microdroplet-tin plasma sources of EUV radiation driven by solid-state-lasers (Topical Review)

Plasma produced from molten-tin microdroplets generates extreme ultraviolet light for state-of-the-art nanolithography. Currently, CO2 lasers are used to drive the plasma. In the future, solid-state mid-infrared lasers may instead be used to efficiently pump the plasma. Such laser systems have promise to be more compact, better scalable, and have higher wall-plug efficiency. In this Topical Review, we present recent findings made at the Advanced Research Center for Nanolithography (ARCNL) on using 1 and 2 µm wavelength solid-state lasers for tin target preparation and for driving hot and dense plasma. The ARCNL research ranges from advanced laser development, studies of fluid dynamic response of droplets to impact, radiation-hydrodynamics calculations of, e.g. ion ‘debris’, (EUV) spectroscopic studies of tin laser-produced-plasma as well as high-conversion efficiency operation of 2 µm wavelength driven plasma.

Fabrication of [formula omitted]As targets for heavy ion nuclear reactions

Thin uniform targets of 75As isotope with Pb/Au backing layer were fabricated for nuclear structure studies and sub-picosecond lifetime measurements of nuclear excited states using the Doppler shift attenuation method (DSAM) for nuclei populated in the heavy-ion induced fusion-evaporation reactions. The 75As targets of thickness 2.8–4.0 mg/cm2 (4.9–7.0μm) were prepared by in-vacuo sublimation of the As metal powder on to the backing (∼10 mg/cm2) of Pb (9.4μm) or Au (5.2μm), which were prepared by rolling method. The prepared targets were further rolled to improve their uniformity and avoid any interlayer gaps. The amount 75As material required for target preparation could be significantly reduced to ∼80 mg by increasing vapour flux by replacing the open dimpled tantalum boat with the pinhole tubular form. The uniformity, purity and thickness of As and Pb layers in the fabricated targets were assessed using a non-destructive Energy dispersive X-ray fluorescence (EDXRF) technique set-up. The measured thickness values of As and Pb/Au layers were found to agree within ∼3% with those deduced from the weighing method. The prepared targets have been successfully used with 28Si and 31P ion beams and the in-beam γ-ray spectroscopic studies in excited nuclear states in 98,99Rh, 99,100,101Pd and 102Ag isotopes.