Single Step Research Articles

Current Management of Choledocholithiasis-narrative Review Article

The most common management of choledocholithiasis involves the two-step method that involves the use of pre-operative endoscopic retrograde cholangiopancreatography (ERCP) followed by laparoscopic cholecystectomy in six weeks’ time. But since the introduction of laparoscopic surgery, laparoscopic common bile duct exploration has been used as a single step method to treat this condition. Another method involves intraoperative endoscopic retrograde cholangiopancreatography (ERCP) and laparoscopic cholecystectomy in the same setting. As there is no consensus on management, we have conducted this review article to look at the various management options for choledocholithiasis.

Development of Dry-herb vaporizer-assisted solid-phase Microextraction for the analysis of volatile Organic compounds

Solid-phase microextraction (SPME) is a simple, efficient, and solvent-free technique. It integrates the steps of traditional liquid-liquid extraction, i.e., sampling, extraction, concentration, derivatization, in a single step. It is easy, combining capability with gas chromatography (GC), liquid chromatography (LC), and mass spectrometry (MS), which makes this method fast, reliable, and sensitive. SPME method is often associated with extraction at elevated temperature, since increasing temperature may positively affect extraction by increasing the analyte volatility, diffusion, and extraction rate. In this work, a dry-herb vaporizer (vaping pen) was used as a sample heating device for direct desorption of volatile analytes into the headspace of the device. The extraction was performed by sorbing analytes from their gas phase in the headspace of the vape onto a SPME fiber followed by desorption in the injection port for GC–MS characterization. Compounds from horseradish, cinnamon, and gasoline-spiked soil samples were analyzed. The samples were also analyzed by conventional headspace SPME-GC–MS. The results from both methods were compared. The methods produce comparable results in terms of extracted compounds and relative area percentages, however, the dry-herb vaporizer had improved sensitivity.

“Surface‐Filming Assembly” Strategy for Facilely Constructing and Adjusting Circularly Polarized Luminescence from Perovskite/Chiral Helical Polyacetylene Films

AbstractTunable circularly polarized luminescence (CPL) has attracted substantial research interest. Till date, the main methods for adjusting CPL is by changing the ratio of fluorescent components and/or regulating external stimuli. Although these adjustment methods have been demonstrated to be reliable, most of them show disadvantages including challenging molecular design, complicated and cumbersome material fabrication, and rigorous adjustment conditions. Herein, the “Surface‐Filming Assembly” (SFA) strategy for conveniently and efficiently modulating CPL by taking the perovskite/chiral helical polyacetylene system as a model is proposed and established. This strategy can facilely achieve multicolor CPL by simply changing the color (or number) of perovskite fluorescent layers and/or the attaching order of the perovskite layers in the assembled multilayer film. Compared with previously reported methods, the SFA strategy integrates the preparation process and adjustment in one single step, simplifying the preparation process (especially the preparation of perovskite with different ratios of halogen atoms) and making adjustment simple and efficient. The SFA strategy and different CPL generation mechanisms to achieve multicolor and white‐color emission with glum up to 10−2 are combined. Based on the CPL film and the solvent sensitivity of perovskite, a solvent‐responsive CPL‐emitting switch and further applied the CPL sample in multiple information displays and encryption are realized.

A Novel Homoconjugated Propellane Triimide: Synthesis, Structural Analyses, and Gas Separation.

Rigid three-dimensional (3D) polycyclic propellanes have garnered interest due to their unique conformational spaces, which display great potential use in selectivity, separation and as models to study through-space electronic interactions. Herein we report the synthesis of a novel rigid propellane, trinaphtho[3.3.3]propellane triimide, which comprises three imide groups embedded on a trinaphtho[3.3.3]propellane. This propellane triimide exhibits large bathochromic shift, amplified molar absorptivity, enhanced fluorescence, and lower reduction potential when compared to the subunits. Computational and experimental studies reveal that the effective through-space π-orbitals interacting (homoconjugation) occurs between the subunits. Single-crystal XRD analysis reveals that the propellane triimide has a highly quasi-D3h symmetric skeleton and readily crystallizes into different superstructures by changing alkyl chains at the imide positions. In particular, the porous 3D superstructure with S-shaped channels is promising for taking up ethane (C2H6) with very good selectivity over ethylene (C2H4), which can purify C2H4 from C2H6/C2H4 in a single separation step. This work showcases a new class of rare 3D polycyclic propellane with intriguing electronic and supramolecular properties.

A Novel Homoconjugated Propellane Triimide: Synthesis, Structural Analyses, and Gas Separation

AbstractRigid three‐dimensional (3D) polycyclic propellanes have garnered interest due to their unique conformational spaces, which display great potential use in selectivity, separation and as models to study through‐space electronic interactions. Herein we report the synthesis of a novel rigid propellane, trinaphtho[3.3.3]propellane triimide, which comprises three imide groups embedded on a trinaphtho[3.3.3]propellane. This propellane triimide exhibits large bathochromic shift, amplified molar absorptivity, enhanced fluorescence, and lower reduction potential when compared to the subunits. Computational and experimental studies reveal that the effective through‐space π‐orbitals interacting (homoconjugation) occurs between the subunits. Single‐crystal XRD analysis reveals that the propellane triimide has a highly quasi‐D3h symmetric skeleton and readily crystallizes into different superstructures by changing alkyl chains at the imide positions. In particular, the porous 3D superstructure with S‐shaped channels is promising for taking up ethane (C2H6) with very good selectivity over ethylene (C2H4), which can purify C2H4 from C2H6/C2H4 in a single separation step. This work showcases a new class of rare 3D polycyclic propellane with intriguing electronic and supramolecular properties.

Performance-based versus conventional seismic design: comparative assessment on a 4-story RC moment frame

AbstractFive different design approaches are compared on a single mid-rise reinforced concrete building, pitting two performance-based designs against three conventional methods in delivering a solution that satisfies different sets of performance objectives. Two of the conventional designs stem from the literature, and they represent 2003 IBC compatible solutions. Another employs the yield point spectra to deliver a code-like solution, satisfying the design norms without needing iterations. The final two are based on the yield frequency spectra to offer a design that can satisfy more detailed performance objectives in a single step. Overall, all five methods are shown to deliver what is expected. Conventional methods can safely capture the code requirements, yet they are disadvantaged when treading in beyond-life-safety territory, where Immediate Occupancy or Collapse Prevention objectives cannot be easily satisfied, a problem that is not shared by performance-based approaches.

One-step online analysis of antibiotics in highly saline seawater by nano-based slug-flow microextraction

The transition to mass spectrometry (MS) in the analysis of antibiotics in the marine environment is highly desirable, particularly in the enhancement of sensitivity for high-salinity (3.5 wt%) seawater samples. However, the persistence of complex operational procedures poses substantial challenges to this transition. In this study, a rapid method for the online analysis of antibiotics in seawater samples via nano-electrospray ionization (nESI) MS based on slug-flow microextraction (SFME) has been proposed. Comparisons with other methods, complex laboratory setups for sample processing are now seamlessly integrated into a single online step, completing the entire process, including desalination and detection, SFME–nESI–MS provides faster results in less than 2 min while maintaining sensitivity comparable to that of other detection methods. Using SFME–nESI, six antibiotics in high-salinity (3.5 wt%) seawater samples have been determined in both positive and negative ion modes. The proposed method successfully detected clarithromycin, ofloxacin, and sulfadimidine in seawater within a linear range of 1–1000 ng mL−1 and limit of detection (LOD) of 0.23, 0.06, and 0.28 ng mL−1, respectively. The method recovery was from 92.8% to 107.3%, and the relative standard deviation was less than 7.5%. In addition, the response intensity of SFME–nESI-treated high-salinity (3.5 wt%) samples surpassed that of untreated medium-salinity (0.35 wt%) samples by two to five orders of magnitude. This advancement provides an exceptionally simplified protocol for the online rapid, highly sensitive, and quantitative determination of antibiotics in high-salinity (3.5 wt%) seawater.

Topological defects in Floquet circuits

We introduce a Floquet circuit describing the driven Ising chain with topological defects. The corresponding gates include a defect that flips spins as well as the duality defect that explicitly implements the Kramers-Wannier duality transformation. The Floquet unitary evolution operator commutes with such defects, but the duality defect is not unitary, as it projects out half the states. We give two applications of these defects. One is to analyze the return amplitudes in the presence of “space-like” defects stretching around the system. We verify explicitly that the return amplitudes are in agreement with the fusion rules of the defects. The second application is to study unitary evolution in the presence of “time-like” defects that implement anti-periodic and duality-twisted boundary conditions. We show that a single unpaired localized Majorana zero mode appears in the latter case. We explicitly construct this operator, which acts as a symmetry of this Floquet circuit. We also present analytic expressions for the entanglement entropy after a single time step for a system of a few sites, for all of the above defect configurations.

Novel purification platform based on multimodal preparative scale separation of mAb fragments and aggregates

Monoclonal antibodies (mAbs) continue to dominate the biopharmaceutical industry. Certain mAbs are prone to fragmentation and clipping and in these cases, adequate removal of these species is critical during manufacturing. Fragments can be generated during fermentation, purification, storage, formulation, and administration. Their addition to the acidic charge-variant of the purified mAb has been reported to decrease stability and potency of the final product. However, contrary to mAb aggregation, manufacturers have not given much attention to removal of fragments and clipped species and as a result most conventional mAb platforms offer at best limited capabilities for their removal. In this study, we propose a novel purification platform that uses multimodal chromatography and achieves complete removal of a range of mAb fragments and clipped products (25–120 kDa). The utility of the platform has been successfully demonstrated for 2 IgG1s and 2 IgG4s. Further, adequate removal of the various host cell impurities such as host cell proteins (<10 ppm) and host cell DNA (<5 ppb) has been achieved. Finally, the platform was able to deliver adequate removal of high molecular weight impurities (<1 %) and a 30 % clearance of the acidic charge variant. The proposed single step has been shown to deliver what the polishing chromatography and intermediate purification chromatography steps deliver in a traditional mAb platform.

A Glycerol promoted, regioselective synthesis of 6‐aryl substituted Imidazo[2,1‐b]thiazole and imidazo[2,1‐b]‐1,3,4‐thiadiazole through a one‐step domino process under green conditions

AbstractIn this study, we present a strategy for synthesizing Imidazo[2,1‐b]thiazole and Imidazo[2,1‐b][1,3,4]thiadiazole in a single step with high efficiency. Glycerol is utilized as a sustainable solvent, offering both economic and non‐toxic properties to facilitate the selective formation of these compounds. The reaction entails a stepwise formation of C−N bonds. Key benefits of this approach include its environmentally conscious reaction conditions, simplicity in execution, cost‐effectiveness, short reaction times, high product yields, solvent reusability, and overall sustainability.

A thermostable and inhibitor resistant β-glucosidase from Rasamsonia emersonii for efficient hydrolysis of lignocellulosics biomass.

The present study reports a highly thermostable β-glucosidase (GH3) from Rasamsonia emersonii that was heterologously expressed in Pichia pastoris. Extracellular β-glucosidase was purified to homogeneity using single step affinity chromatography with molecular weight of ~ 110kDa. Intriguingly, the purified enzyme displayed high tolerance to inhibitors mainly acetic acid, formic acid, ferulic acid, vanillin and 5-hydroxymethyl furfural at concentrations exceeding those present in acid steam pretreated rice straw slurry used for hydrolysis and subsequent fermentation in 2G ethanol plants. Characteristics of purified β-glucosidase revealed the optimal activity at 80°C, pH5.0 and displayed high thermostability over broad range of temperature 50-70°C with maximum half-life of ~ 60h at 50°C, pH 5.0. The putative transglycosylation activity of β-glucosidase was appreciably enhanced in the presence of methanol as an acceptor. Using the transglycosylation ability of β-glucosidase, the generated low cost mixed glucose disaccharides resulted in the increased induction of R. emersonii cellulase under submerged fermentation. Scaling up the recombinant protein production at fermenter level using temporal feeding approach resulted in maximal β-glucosidase titres of 134,660units/L. Furthermore, a developed custom made enzyme cocktail consisting of cellulase from R. emersonii mutant M36 supplemented with recombinant β-glucosidase resulted in significantly enhanced hydrolysis of pretreated rice straw slurry from IOCL industries (India). Our results suggest multi-faceted β-glucosidase from R. emersonii can overcome obstacles mainly high cost associated enzyme production, inhibitors that impair the sugar yields and thermal inactivation of enzyme.

Silver-infused TiO2 nanowires and unveiling their potential for superior wastewater dye remediations.

Silver infused ultrathin TiO2 nanowires (NWs) were synthesized via a single step solvothermal approach. The crystallinity, structure, and morphology were determined to understand the physicochemical nature of the nanocomposites. The catalytic efficiency of the newly synthesized nanocatalysts was tested for the textile waste treatment taking methylene blue (MB) as model pollutant under solar light irradiations. Nearly 96% photodegradation efficiency for MB was achieved within 20 min. Furthermore, the recyclability of the photocatalyst was also studied, and the material remained stable and effective up to four consecutive runs. RESEARCH HIGHLIGHTS: Precise size-controlled synthesis of Ag-incorporated titania nanowires (ATNWs) Controlled aspect ratios, with tunable lengths and diameters (100-3 nm) via precursor and surfactant optimization Demonstrated ATNWs' efficiency in degrading toxic dye, methylene blue (MB) 96% photodegradation efficiency for MB achieved within 20 min using 3 nm thick annealed TiO2 NWs Recyclability efficiency of photocatalyst, which remained stable and effective for up to four consecutive runs.

Design of rural tourism management cloud platform based on intelligent audio processing and sensor navigation positioning

People's living standards are constantly improving, and many people are eager to travel, especially to rural areas, which has become a tourism trend, which has also driven the local economy. Each place is actively utilizing the advantages of its own region to establish a unique tourism economic industry chain and seek the interests of local villagers. Based on this, this article takes the specific development of contemporary rural tourism industry as the basic research object, and develops a specialized rural tourism management cloud service system platform. The system mainly relies on intelligent audio processing and related navigation and positioning functions. By finely processing the collected intelligent audio signals, utilizing specialized data conversion tools to improve the accuracy of the collected signals, and using a linear aliasing model to handle subsequent problems. We also propose a carrier based system coordinate for navigation and positioning algorithms, which can estimate the optimal information value among them. In addition, this article also conducted a specific analysis of the performance of two models, namely the single step model and the Seq2Seq model. The tourism management cloud service system platform for rural areas based on intelligent audio related processing and precise navigation positioning proposed in this article can effectively promote the development of local rural tourism and improve the quality of life of villagers.

A global analysis of the introduction pathways and characteristics associated with non-native fish species introduction, establishment, and impacts

BackgroundThe invasion success of introduced freshwater fishes is influenced by many factors, including ecological, species, and socioeconomic characteristics. Most studies that document the importance of these characteristics are conducted at local scales and/or focus on a single step of the invasion process. In this study, we aim to determine the species characteristics, ecological characteristics, and socioeconomic characteristics of non-native freshwater fish invasions. Our assessment was done at the global scale and considers all three steps of the invasion (i.e., introduction, establishment, and impact). For this purpose, we applied generalized linear models to 20 variables collected for 307 non-native species and modeled them as a function of ecological characteristics (i.e., environmental features), species traits (i.e., functional and morphological), and socioeconomic characteristics (i.e., human use and introduction pathways). We considered the number of countries in which each species was introduced, established, or had ecological impacts as a proxy of invasion step success. We also explored the specifics of species introduced through the aquaculture and the ornamental fish trade pathways.ResultsWe found that non-native freshwater fishes with broad diets, high parental care, and multiple introduction pathways are the most widely introduced and established worldwide. The number of countries with impacts reported was best explained by the type of introduction pathway (i.e., aquaculture or fisheries). Moreover, among non-native species introduced through aquaculture, those belonging to Cypriniformes and having broad diets were the most widely introduced and established species. In contrast, the species introduced through the ornamental fish trade pathway belonged to various taxonomic orders but were mainly native to tropical regions.ConclusionsConsidering several types of factors is important when analyzing the invasion success of freshwater fish and disentangling the different invasion steps. These findings have strong implications for anticipating the profile of species with a high potential to invade many countries.

Direct alcoholysis of furfuryl alcohol to alkyl levulinates using nano-crystalline polyoxometalate-hexamethylphosphoramide salt as a defined solid Brønsted acid catalyst

A nano-crystalline cubic-type, organo-polyoxometalate salts prepared in a single step via quaternization of phosphotungstic acid (PWA) and hexamethylphosphoramide (HMPA) with different rations PWA-HMPA (1:1 to 1:3). The catalysts preserved their solid forms without hydrolysis of HMPA as verified through FT-IR and XRD analyses. A cubic nano-crystalline structure of the catalyst PWA-HMPA (1:3) was revealed by HR-TEM and FE-SEM and defined with moderate and strong Brønsted acid sites (1.19 mmols/g) remarkably provided 99 % conversion of FAL with 98 % selectivity for isopropyl levulinate (IPL) in one hour at 145 °C using isopropanol (IPA) as solvent. Two distinct reaction pathways over PWA-HMPA (1:3) observed with linear alcohols via 1,2 addition/tri-alkoxy intermediate showed lower AKLs selectivity while favouring high selectivity in IPA through 1,4 addition/furan ring opening. PWA-HMPA (1:3) exhibited notable stability over six recycling runs without leaching HMPA or PWA components, indicating its environmental compatibility.

Cell harvesting on robust smart thermosensitive pseudo-double networks prepared by one-step procedure

In this work, pseudo-double networks (pseudo-DN) based on N-vinyl caprolactam (VCL, major component, precursor of thermosensitive chains) and hexyl methacrylate (HMA, minor component, hydrophobic) have been prepared by using single step approach. The adjective pseudo refers to the fact that through the simultaneous copolymerization of VCL and HMA with different relative reaction kinetics, in the presence of an appropriate mixture of crosslinkers, networks with complex structures that tend towards DN-type structures are obtained. Hydrogels have been prepared with HMA/VCL molar ratios from 0 to 23.2 mol %. The series of hydrogels prepared show a composition-dependent behaviour in terms of thermosensitivity, swelling at temperatures below the Volume Phase Transition Temperature (VPTT) value, mechanical properties and performance during the cell culture experiments. More precisely, hydrogels with low percentages of HMA show elastic moduli under compression tests slightly lower than 1 MPa and presented a high thermal response (high swelling below the VPTT) allowing in addition the non-aggressive detachment of cell monolayer by controlled decrease of temperature. As the percentage of HMA increases, the elastic modulus increases, obtaining improved mechanical properties (reaching values in the range 1–3 MPa), thermosensitivity decreases (low swelling below VPTT) and a progressive delay in cell proliferation is also observed, being still cytocompatible. In this sense, hydrogels with low percentages of HMA (up 2.7 mol %) allow cell proliferation and transplantation similar to the control sample.

A Novel Approach for Single Step Analyte Fractionation of Raw Milk Prior to Antbiotica Residue Trace Analysis as an Alternative to QuEchERS Based Extraction.

Antibiotic residues in milk are a well-known hazard in the dairy food chain. Detection methods for these residues, such as non-specific microbiological inhibitor tests or group-specific receptor tests, respectively, are relatively inexpensive, easy to use and widely applied to ensure food safety. In contrast, specific detection by liquid chromatography tandem mass spectrometry (LC-MS/MS) - although a critical, complimentary method to confirm the results of non-specific testing-is relatively costly, time consuming and laborious. Furthermore, sample processing before LC-MS/MS analysis requires unique preparation procedures for different groups of antibiotic compounds. To simplify and speed up specific antibiotic residue detection, a low-cost, passive and single-step method to fractionate analytes in raw milk was developed. Untreated raw milk was fractionated into its water and fat/protein phases using a FraMiTrACR® AB fractionation unit. The water fraction was then analyzed by LC-MS/MS. The analyte fractionation method was evaluated against a QuEChERS based method for sample preparation. Our method allows qualitative and quantitative detection of substances from the Penicillin, Cephalosporin, Macrolide, Lincosamide, Sulfonamide, Tetracycline and Fluoroquinolone groups of antibiotics. Detection limits are below the legally prescribed maximum residue levels, allowing reliable, specific and rapid validation of a positive result in non-specific microbiological inhibitor tests. Analyte fractionation by FraMiTrACR® AB is a faster alternative to QuEChERS based sample preparation for the detection of antibiotic substances in milk. This method describes a low-cost, environmentally friendly, passive and single-step milk analyte fractionation. As an alternative to QuEChERS based preparation, this fractionation method simplifies and speeds up the process for specific antibiotic residue detection.

Simplifying Access to Targeted Protein Degraders via Nickel Electrocatalytic Cross-Coupling.

C-C linked glutarimide-containing structures with direct utility in the preparation of cereblon-based degraders (PROTACs, CELMoDs) can be assessed in a single step from inexpensive, commercial α-bromoglutarimide through a unique Brønsted-acid assisted Ni-electrocatalytic approach. The reaction tolerates a broad array of functional groups that are historically problematic and can be applied to the simplified synthesis of dozens of known compounds that have only been procured through laborious, wasteful, multi-step sequences. The reaction is scalable in both batch and flow and features a trivial procedure wherein the most time-consuming aspect of reaction setup is weighing out the starting materials.

One-Step Synthesis of TiO2/SiO2-np Nanocomposite Photocatalytic Multilayer Films: Effect of Incorporation Time Sequences of SiO2 Nanoparticles during the TiO2 Film Growth.

In this article, the TiO2/SiO2-np nanocomposite multilayer films were synthesized in a single step by reactive magnetron sputtering combined with a nanoparticle aerosol jet. The SiO2 nanoparticles (SiO2-np) were introduced into a growing TiO2 thin film with different time sequences during deposition for a fixed duration. The SiO2-np acting as impurities are introduced into the TiO2 to willingly disturb its growth and to cause growth defects in order to increase the specific surface area of the photocatalytic film. In reason of the non-photoactive properties of the SiO2 nanoparticles, their introduction allows us to study only the effects induced on the film morphology, microstructure, and photocatalytic properties by their incorporation. The fractographies and topographies reveal strong changes in the morphologies depending on the time sequence of the nanoparticle introduction in the thin films. The introduction of SiO2-np from the beginning of the TiO2 film growth leads to the formation of high and large growth defects resulting in a highly diffusive surface. In addition, XRD analysis shows that the crystallite size tends to decrease as the composite film layer gets closer to the surface. Their photocatalytic performance is obtained by following the degradation of orange G dye under UV-visible irradiation. The photocatalytic performance is not only related to the specific surface area of the catalyst film, and the coverage of the photoactive phase on the surface, but also to the crystal quality of the photoactive phase. Furthermore, the samples exhibit good photostability, maintaining the same activity after four degradation cycles. In the specific case of TiO2/SiO2-np, it is demonstrated that the introduction of the nanoparticles only at the beginning of the film growth is more efficient than a continuous introduction. This result suggests that this original process allows the use of a relevant strategy for the nanoparticle introduction according to the required functionality.

Application of the kinetic polynomial idea to describe catalytic hydrogenation of propene

AbstractThe kinetics of heterogeneous catalytic reactions is a topic of theoretical and practical importance that combines theoretical and experimental efforts to achieve a deeper insight into the process. Theoretical aspects are concerned with determination of the process mechanism, whereas in practical applications kinetic experiments are applied to assist reactor design and scaling up of various processes. These approaches overlap; basis of the assumed mechanism that consists of many elementary steps, it is possible to find a kinetic equation for which precision is verified by comparison with experimental data. The method most often applied requires finding a single step that has the strongest influence on the process rate. This “classical approach” fails if the rate of two or more steps has comparable values, the precision of the determined kinetic rate becomes only average or even low. Such accuracy was observed, among others, for the gas‐phase hydrogenation of propene. The reaction is easy to carry out and proceeds under mild conditions; the byproducts are not observed. It suggests that there cannot be a single dominating effect step on the process rate. In this work, the application of the polynomial kinetic idea to the gas‐phase hydrogenation of the propene process realized in practice is tested. An attempt of obtaining a handy and precise relationship, without insignificant parameters was made. To realize this, the theoretical form of the polynomial kinetic was derived, and then, using statistical analysis of estimated polynomial parameters, the kinetic relationship was simplified. The final version of the kinetic polynomial and some selected kinetic equations taken from the literature were compared with respect to precision. The differences were significant: the precision of anticipation of the kinetic rate by the polynomial kinetic was 5% higher than for the power law and 12% higher than for the LHHW kinetic.