Propylene Research Articles

Synthesis of α-Boryl-α-Substituted Allylboronates from Propyne.

A novel method for the two-step synthesis of α-boryl-α-substituted allylboronates from propyne is described. These allylboronates are prepared by the Co-catalyzed 1,1-diboration reaction of propyne with B2pin2, followed by the base-mediated alkylation reaction of 1,1-di(boryl)propene at the α-position. Computational studies revealed the origins of observed reactivity and selectivity in the base-mediated alkylation reaction. The resulting α-boryl-α-methyl-allylboronate is applied to the allylation of aldehydes, which gives homoallylic alcohols with a trisubstituted alkene moiety.

VOC Detection with Zinc Oxide Gas Sensors: A Review of Fabrication, Performance, and Emerging Applications

Energy‐efficient, high‐specificity gas sensors provide practical suitability for stability and response factors. The recognition of ignitable gases (methane (CH <sub>4</sub>), propane (C <sub>3</sub>H <sub>8</sub>), and hydrogen (H <sub>2</sub>) and harmful gases (carbon oxide (CO) and hydrogen sulfide (H <sub>2</sub>S)) in an enclosed and out‐of‐door space are essential to safeguard the human lives and infrastructural spaces. One of the crucial conductive‐type metal oxide semiconductor (MOS) gas sensors yielding wide applications is zinc oxide (ZnO). This study highlights the various types of ZnO gas sensors, their fabrication techniques, and specific vital characterizations. The devices based on MOS are utilized to sense various target gases through redox reactions. The variation in oxide surface with target gas interactions is transduced to a change of sensor conductance. This review also provides insight into integrating ZnO gas sensors with technologies such as materials engineering, the Internet of things and big data. Moreover, this review addresses ZnO gas sensors' challenges and future directions.

Anhydrous microwave synthesis as efficient method for obtaining model advanced glycation end-products

IntroductionAdvanced glycation end-products (AGEs) are capable of stimulating oxidative stress and inflammation. This study investigates the synthesis of medium crosslinked AGEs (the most optimal form of AGEs because of soluble in water, used in many assays as markers) and their biochemical properties.MethodsOne of model protein–myoglobin from horse heart muscle (MB) and a chosen respective glycation factor – D-melibiose (mel), acrolein (ACR), D-glucose (glc), 4-hydroksynonenal (4HNE), trans-2-nonenal (T2N), methylglyoxal (MGO) – were subjected to high temperature water synthesis (HTWS) and high temperature microwave synthesis in anhydrous conditions (HTMS). The syntheses were deliberately carried out in two different conditions to check whether adding an additional energy source (microwaves) while lowering the temperature and shortening the reaction time would allow for more effective obtaining of medium-cross-linked AGEs, monitored with SDS-PAGE. Products were analyzed using fluorescence measurements, Enzyme-Linked Immunosorbent Assay (ELISA) and immunoblotting tests and electrophoretic mobility shift assay to evaluate their ability to activate nuclear factor kappa-light-chain-enhancer (NF-κB).ResultsMedium cross-linked AGEs were more efficiently obtained in HTMS. Fluorescence was high for MB-ACR, MB-T2N and MB-glc products. Anti-MAGE antibodies showed reactivity towards MB-mels of HTMS and HTWS, and the MB-4HNEs from HTMS. HTWS products, apart from MB-ACR, did not activate NF-κB, whereas MB-ACR, MB-4HNE, MB-mel, and MB-T2N products of HTMS strongly activated this factor that indicates their strong pro-inflammatory properties.ConclusionHTMS is a fast and efficient method of synthesizing medium cross-linked AGEs.

Atmospheric Fungal Spore Injection: A Promising Breakthrough for Challenging the Impacts of Climate Change Through Cloud Seeding and Weather Modification

Cloud seeding is a technique used to enhance precipitation in drought-prone areas, support agricultural productivity, ensure water supply for human consumption, improve hydropower generation from dams, lessen hurricanes, cool urban heat, and disperse fog in airports. Growing global population size and climate change are the biggest impetus for weather modification and cloud seeding operations. Currently, salt powders like silver iodide, potassium iodide, sodium chloride, calcium chloride, dry ice (solid carbon dioxide), and liquid propane are widely used as ice nucleating particles for cloud seeding purposes while in natural cloud formation, and precipitation particles from dust storms, mineral dust and biological aerosols (like spores, pollen, bacteria) are the dominant ice nucleators. Having this knowledge on hand and the ubiquitous nature of fungi on the other hand; it is feasible to exploit the ice nucleating ability of fungal spores and use it as potential candidates for cloud seeding and weather modification operations.

Photocatalytic Aldehyde Allylation for Site‐Specific DNA Functionalization

Comprehensive SummaryEnhancing the DNA toolbox with innovative photochemical reactions is pivotal for advancing nucleic acid‐based technologies. Aldehyde groups, versatile bioorthogonal handles for imine formation under acidic conditions, are particularly valuable due to their roles in nucleic acid epigenetics. Here, we present the first photocatalytic on‐DNA aldehyde allylation, enabling precise DNA functionalization under mild, neutral aqueous conditions. Our approach utilizes a photocatalytic polarity‐reversal reaction between DNA‐conjugated benzaldehydes and allyl sulfones. This reaction demonstrates exceptional chemoselectivity while preserving DNA integrity. By varying allyl sulfones, we achieve site‐specific labeling of non‐native DNA with the aldehyde group and cross‐linking with DNA‐bearing allyl sulfones. Furthermore, our method facilitates selective labeling and pull‐down enrichment of 5‐formylpyrimidine nucleotides among complex cellular DNA. This photocatalytic on‐DNA aldehyde transformation expands the limited bioorthogonal photochemical toolboxes, providing novel avenues for functionalizing both non‐native and native aldehyde modifications on DNA.

Diffusion and mobility measurements for propane gas with a nanodosimetric detector

For the operation of nanodosimetric detectors with propane gas, it is essential to know the gas properties at room temperature, such as drift velocity, ion mobility, longitudinal and transversal diffusion coefficients. For propane gas there is only limited experimental data available for the ion mobility and transverse diffusion coefficients. In this work, the drift velocities and ion mobilities for propane were obtained over the reduced electric field range E/N from 24 to 212 Td (1 Td = 10−17 Vcm2) based on arrival time measurements. The reduced ion mobility K0 for propane was determined to be (0.71±0.09) cm2/Vs. The longitudinal diffusion coefficients were determined from the widths of the experimental arrival time spectra and found to be NDL = (3.7 ± 0.5)⋅1019 1/ms in the low field limit below 30 Td.The results presented in this work extend the range of available experimental data for propane, as well as introduce first experimental measurements of the longitudinal diffusion coefficient of propane.

Microwave-assisted pyrolysis of low-density polyethylene (LDPE)to value-added products over HY, HZSM-5 and Hβ catalyst

To reduce carbon emissions, environmental pollution, and to improve the circular economy, a microwave (MW) assisted pyrolysis of low-density polyethylene (LDPE)was carried out to yield valuable products such as aromatics, hydrogen, ethylene, and propylene gas. All three catalysts HY, HZSM-5 and Hβ were used as in-situ catalysts. Catalytic pyrolysis with HY, HZSM-5, and Hβ exhibited a lower liquid yield compared to non-catalytic pyrolysis. Gaseous fraction was mainly comprised of hydrogen, methane, ethylene, ethane, propylene, propane, and butane. It was found that methane (30.77 vol%) and hydrogen (55.24 vol%) were dominating gaseous products at 400 °C and 450 °C respectively using HY to LDPE ratio of 1:10. Whereas HZSM-5 facilitates formation of methane (65.94 vol%) at 400 °C and Ethylene (43.55 vol%) at 550°C. Hβ contributes to formation of alkanes and aromatics and gaseous products consist of majorly C3-C4 hydrocarbon gases which consist of 69.35 % propylene at 450°C. No sign of catalyst deactivation was observed even after 3 repetitive cycles.

Deciphering origins of hydrocarbon deposits by means of intramolecular carbon isotopes of propane adsorbed on sediments

Hydrocarbons are one of the important fluids within the Earth’s crust, and different biotic and abitoic processes can generate hydrocarbon during geological periods. Tracing the sources and sinks of hydrocarbons can help us better understand the carbon cycle of the earth. In this study, an improved approach of adsorbed hydrocarbons extraction from sediments was established. The improved thermal desorption approach, compound-specific isotope analysis and position-specific isotope analysis were integrated to investigate the molecular and intramolecular isotope fractionation between trace hydrocarbon gases within sediments and geological hydrocarbon deposits. The isotopic compositions of the terminal position carbon of propane (δ13Cterminal) serves as a correlation indicator between trace hydrocarbon gases within sediments and geological hydrocarbon deposits. The tight sandstone gas from the Turpan-Hami Basin is a first case study for the application of this novel method to trace hydrocarbon origins. The results showed that the hydrocarbons in the tight sandstone gases in the study area most likely originated from humic organic matter (type III kerogen) at an early mature stage. δ13Cterminal values of the thermally desorbed propane gases from different source rocks were distinguishable and the values of the tight sandstone gases significantly overlap with those of the Lower Jurassic Sangonghe source rocks, suggesting their genetic relationship. Overall, the results provided novel position-specific carbon isotopic constraints on origins of hydrocarbons.

Managing massive submacular hemorrhage using intravitreal brolucizumab in combination with subretinal tissue plasminogen activator and non-expansile gas – A case report

We report a case of a 60-year-old lady presented to us with a sudden painless diminution of vision in the left eye (LE). Her best-corrected visual acuity (BCVA) was counting fingers close to face in the LE. She was diagnosed with submacular hemorrhage (SMH) secondary to polypoidal choroidal vasculopathy (PCV). We performed a standard 25-gauge pars plana vitrectomy with subretinal tissue plasminogen activator injection along with an intravitreal injection of brolucizumab and perfluoro propane (C3F8) gas injection. Six weeks after the procedure, her BCVA improved to counting fingers at three meters. After another two injections of brolucizumab at one-month intervals, the BCVA improved to 6/9, N6. We present the long-term follow-up of this eye for nearly 18 months with improved visual acuity, that is, 6/36, N24 at the final visit. This technique shows favorable results in the case of massive SMH due to PCV.

Selection of propulsion characteristics for systematic assessment of future European RLV-options

AbstractThe propulsion system as the key-element of any space transportation concept is systematically investigated supporting a study on potential future European RLV. Different liquid propellant combinations are compared and evaluated. Subsequently, main stage rocket engines are defined for the two cycle options: open gas-generator and closed staged-combustion. Four different propellant combinations are considered all based on liquid oxygen (LOX) as oxidizer and with the fuel options liquid hydrogen (LH2), liquid methane (LCH4), liquid propane (LC3H8) and kerosene (RP1). These combinations result in eight different generic engines with sub-variants using different nozzle expansion ratios in first and upper stage application. Engine characteristics are similar, as far as conceivable, to be well-suited for the system level comparison of pre-defined RLV-launchers. However, characteristics are not necessarily identical as different engine architectures and propellants might make individual choices necessary. Engine performance characteristics are compared with similar existing engines when available. It is shown that closed-cycle staged combustion engines bring significant performance gains, particularly in sea-level operations. On the other hand, hydrocarbon- and open-cycle gas-generator engines offer a better thrust-to-weight-ratio than hydrogen and staged combustion cycle.

Acrolein scavengers and detoxification: From high-throughput screening of flavonoids to mechanistic study of epigallocatechin gallate

Acrolein (ACR) is a widespread, highly toxic substance that poses significant health risks. Flavonoids have been recognized as effective ACR scavengers, offering a possible way to reduce these risks. However, the lack of specific high-throughput screening methods has limited the identification of ACR scavengers, and their actual detoxifying capacity on ACR remains unknown. To address this, we developed a high-throughput screening platform to assess the ACR scavenging capacity of 322 flavonoids. Our results showed that 80.7 % of the flavonoids could scavenge ACR, but only 34.4 % exhibited detoxifying effects in an ACR-injured QSG7701 cell model. Some flavonoids even increased toxicity. Structure-activity relationship (SAR) analysis indicated that galloyl and pyrogallol units enhance scavenging but worsen ACR-induced cytotoxicity. Further investigation revealed that epigallocatechin gallate (EGCG) could exacerbate ACR-induced redox disorder, leading to cell apoptosis. Our findings provide crucial data on the scavenging and detoxifying capacities of 322 flavonoids, highlighting that ACR scavengers might not mitigate ACR-induced toxicity and could pose additional safety risks.

Cu‐Catalyzed Enantioselective Borylative Desymmetrization of 1‐Vinyl Cyclobutanols and Axial‐to‐Point Chirality Transfer in a Diastereoconvergent/Stereoretentive Allylation Scenery

AbstractCu‐catalyzed asymmetric allylic borylation of 3,3’‐disubstituted 1‐vinylcyclobutan‐1‐ols renders axially chiral allylborane systems, with high asymmetric induction for both enantiomers, by precise selection of the cis or trans substrate. The enantioenriched alkylidenecyclobutanes served as chiral platform to prove the conceptually challenging transference of the axial‐to‐point chirality through two new stereocenters and one pseudoasymmetric carbon generated via diastereoconvergent allylation of aldehydes, without enantioselective erosion.

Cu-Catalyzed Enantioselective Borylative Desymmetrization of 1-Vinyl Cyclobutanols and Axial-to-Point Chirality Transfer in a Diastereoconvergent/Stereoretentive Allylation Scenery.

Cu-catalyzed asymmetric allylic borylation of 3,3'-disubstituted 1-vinylcyclobutan-1-ols renders axially chiral allylborane systems, with high asymmetric induction for both enantiomers, by precise selection of the cis or trans substrate. The enantioenriched alkylidenecyclobutanes served as chiral platform to prove the conceptually challenging transference of the axial-to-point chirality through two new stereocenters and one pseudoasymmetric carbon generated via diastereoconvergent allylation of aldehydes, without enantioselective erosion.

Assessing personal PM2.5 exposure using a novel neck-mounted monitoring device in rural Rwanda

There is growing global concern regarding the detrimental health impacts of PM2.5 emissions from traditional stoves that utilize polluting fuels. Conventional methods for estimating daily personal PM2.5 exposure involve personal air samplers and measuring devices placed in a waist pouch, but these instruments are cumbersome and inconvenient. To address this issue, we developed a novel neck-mounted PM2.5 monitoring device (Pocket PM2.5 Logger) that is compact, lightweight, and can operate continuously for 1 week without recharging. Twelve participants who utilized charcoal, firewood, or propane gas for cooking in rural regions of Rwanda wore the Pocket PM2.5 Logger continuously for 1 week, and time-series variations in personal PM2.5 exposure were recorded at 5-min intervals. Individual daily exposure concentrations during cooking differed significantly among users of the different fuel types, and PM2.5 exposure was at least 2.6 and 3.4 times higher for charcoal and firewood users, respectively, than for propane gas users. Therefore, switching from biomass fuels to propane gas would reduce daily individual exposure by at least one-third. An analysis of cooking times showed that the median cooking time per meal was 30 min; however, half the participants cooked for 1.5 h per meal, and one-third cooked for over 4.5 h per meal. Reducing these extremely long cooking times would reduce exposure with all fuel types. The Pocket PM2.5 Logger facilitates the comprehensive assessment of personal PM2.5 exposure dynamics and is beneficial for the development of intervention strategies targeting household air pollution.

Axially Chiral N‐Oxide Catalysts for the Allylation and Crotylation of Aromatic Aldehydes: Exploiting Nonlinear Effects

AbstractA new family of IAN‐type amine N‐oxides is presented as catalysts for the allylation and crotylation of aromatic aldehydes with allyltrichlorosilanes. These reaction exhibit a remarkably positive nonlinear effect which enables utilization of the catalysts in subenantiopure form. As enantiopure catalysts are not required under this regime, the synthesis of these N‐oxides is straightforward through catalytic asymmetric synthesis, avoiding lenghty synthesis from the chiral pool or resolution of diastereoisomers. Studies of the corresponding crotylation with Z‐ and E‐crotylsilanes suggest that the reaction proceeds through a chair‐like transition state.

Using Municipal Solid-Waste Incinerator Fly Ash, Wash Water, and Propylene Fibers in Self-Compacting Repair Mortar, Greenhouse Gas Emissions Potential

Wash water, municipal solid waste incineration (MSWI) fly ash, and propylene (PP) fibers were employed simultaneously to produce self-compacting repair mortar (SCRM). Different SCRM mixtures were utilized, incorporating 35, 70, and 140 kg/m3 of MSWI fly ash, along with 0.1% of PP fibers. The research focused on investigating the workability, mechanical properties, and global warming potential (GWP) of SCRM. The incorporation of MSWI fly ash and wash water in SCRM resulted in reduced workability, necessitating an increase in the use of superplasticizer. Adding MSWI fly ash decreases compressive strength. The minimum compressive strength was observed when employing 140 kg/m3 of MSWI fly ash and wash water instead of tap water simultaneously. By increasing the proportion of MSWI fly ash content and correspondingly reducing the cement content in SCRM samples, there was a decrease in flexural strength. The ultrasonic pulse velocity (UPV) of all SCRM samples falls within acceptable range. Adding MSWI fly ash to SCRM reduces fracture toughness, and the concurrent use of wash water and MSWI fly ash significantly decreases fracture toughness. Incorporating PP fibers into SCRM resulted in increased compressive strength. Utilizing wash water and MSWI fly ash in SCRM significantly reduces GWP. The avoidance of wash water consumption mitigates the environmental impact of SCRM.

Numerical simulation study on propane gas leakage and diffusion law in slope terrain

AbstractIt is frequent that gas leakage accidents occur at chemical enterprises located in slope terrain. Meet the requirement of urgently studying the gas leakage and diffusion law in slope terrain. In this study, we utilize computational fluid dynamics (CFD) to simulate the scenarios of propane leakage and diffusion under four distinct slope conditions, which are 0°, 10°, 15°, and 20°. The gas diffusion law under different slopes is investigated, and the influence of wind speed and wind direction on the diffusion process is also further analyzed. The study indicates that when the slope exceeds 15°, the change in slope exerts a pronounced influence on the dispersion of propane leakage. Compared with diffusion on flat ground, there is a distinct propane aggregation area at the bottom of the slope terrain. Also, the steeper the slope, the more noticeable the aggregation phenomenon. The increase of wind speed makes propane gas lifted, and the gas aggregation at the bottom of the slope decreases. In particular, at a wind speed of 3.3 m/s, the aggregation of propane at the bottom of the first 15° and 20° slopes is more pronounced. Under the upwind condition, the propane gas is entrained at the slope surface, increasing the propane concentration in the area around the tank, which in turn increases the safety risk. The findings of this study have significant implications for the rational layout of chemical enterprises, gas leakage monitoring, and emergency evacuation planning for leakage accidents. They can also help enhance chemical enterprises' safety prevention abilities and the efficiency of their emergency response.

Visual detection of aldehyde gases using a silver-loaded paper-based colorimetric sensor array

The small molecule aldehydes are volatile organic compounds (VOCs), possessing cytotoxicity and carcinogenicity. Long-term exposure can pose a serious threat to human health. Based on an in-situ reduction colorimetric method to generate silver nanoparticles and induce colorimetric response, we proposed a silver-loaded paper-based colorimetric sensor array for visually detecting and differentiating five relatively common trace small molecule aldehyde gases. The silver ions are immobilized onto a porous filter paper and stabilized by complexing agents of branched polyethyleneimine, ethylenediamine, and 1,6-diaminohexane, respectively. The as-fabricated sensor array expresses remarkable stability and capacity to resist humidity. The qualitative analysis reveals that the sensor array has excellent selectivity for aldehyde gases and displays remarkable anti-interference ability. The quantitative analysis indicates that the sensor array exhibits superior sensitivity for five aldehyde gases, with limits of detection (LODs) of 9.0 ppb for formaldehyde (FA), 3.1 ppm for acetaldehyde (AA), 3.5 ppm for propionaldehyde (PA), 23.8 ppb for glutaric dialdehyde (GD), and 71.5 ppb for hydroxy formaldehyde (HF), respectively. Importantly, these LODs are all comfortably below their respective permissible exposure limits. A unique colorimetric response fingerprint is observed for each analyte. Standard chemometric methods illustrate that the sensor array has excellent clustering capability for these aldehyde gases. Additionally, the sensor array's response is irreversible and possesses outstanding performance for cumulative monitoring. This colorimetric sensor array based on silver ions reduced to silver nanoparticles offers a novel detection method for the continuous, ultrasensitive, and visual detection of trace airborne pollutants.

Photoredox/Nickel Dual-Catalyzed Allylation of Aldehydes with Allylic Alcohols and Mechanistic Insights in the Presence of CO2

Photoredox/Nickel Dual-Catalyzed Allylation of Aldehydes with Allylic Alcohols and Mechanistic Insights in the Presence of CO₂

From Building Blocks to Catalysts: The Underinvestigated Potential of Boronic Acid Esters.

Lewis acids are crucial in chemistry, with applications in pharmaceuticals, agrochemicals, and materials science. In main-group chemistry, they offer alternatives to transition metals, prompting our study of halogenated boronic acid esters (BAEs). Although BAEs are well-known, their catalytic potential has been overlooked. Our investigation found their Lewis acidity superior to that of boron trifluoride and comparable to that of tris(pentafluorophenyl)borane. Additionally, their catalysis of the Sakurai allylation of aldehydes has been documented, paving the way for future advancements.