Numerical study on the stimulation effect of boundary sealing and hot water injection in marine challenging gas hydrate extraction.

This study proposed a novel development mode combining boundary sealing and hot water injection to address the challenges of gas leakage, limited reservoir sensible heat, boundary water intrusion, and low productivity faced by challenging hydrate extraction, and the stimulation effect was numerically investigated with Shenhu hydrates as the geological background. The results showed that lower boundary permeability facilitated pressure propagation and achieved volumetric dissociation of hydrates, whereas insufficient formation energy resulted in substantial gas retention. Hot water injection was effective for stimulation, but open boundaries could not maintain the high injection pressure, leading to massive hot water losses and gas escapes. However, their combination achieved a synergistic stimulation like "1 + 1 > 2" because a piston water drive similar to secondary recovery in oil and gas development was formed. Relative to three-spot well patterns, the five-spot shortened the extraction cycle by 680 days and enhanced the gas-to-water ratio by 17%. Increasing injection pressure enhanced water yield more significantly while the improvement of gas yield was more significant by increasing hot water temperature. Overall, high-pressure and high-temperature injection was suggested for gas enhancement and water control. These findings provide important guidance for advancing the commercial development of challenging hydrates.

Physiological Characteristics and Transcriptomic Responses of Pinus yunnanensis Lateral Branching to Different Shading Environments.

Pinus yunnanensis is an important component of China's economic development and forest ecosystems. The growth of P. yunnanensis seedlings experienced a slow growth phase, which led to a long seedling cultivation period. However, asexual reproduction can ensure the stable inheritance of the superior traits of the mother tree and also shorten the breeding cycle. The quantity and quality of branching significantly impact the cutting reproduction of P. yunnanensis, and a shaded environment affects lateral branching growth, development, and photosynthesis. Nonetheless, the physiological characteristics and the level of the transcriptome that underlie the growth of lateral branches of P. yunnanensis under shade conditions are still unclear. In our experiment, we subjected annual P. yunnanensis seedlings to varying shade intensities (0%, 25%, 50%, 75%) and studied the effects of shading on growth, physiological and biochemical changes, and gene expression in branching. Results from this study show that shading reduces biomass production by inhibiting the branching ability of P. yunnanensis seedlings. Due to the regulatory and protective roles of osmotically active substances against environmental stress, the contents of soluble sugars, soluble proteins, photosynthetic pigments, and enzyme activities exhibit varying responses to different shading treatments. Under shading treatment, the contents of phytohormones were altered. Additionally, genes associated with phytohormone signaling and photosynthetic pathways exhibited differential expression. This study established a theoretical foundation for shading regulation of P. yunnanensis lateral branch growth and provides scientific evidence for the management of cutting orchards.

Optimization of ultrasound-assisted extraction of Imperata cylindrica polysaccharides and evaluation of its anti-oxidant and amelioration of uric acid stimulated cell apoptosis.

An efficient, cost-effective and environmentally friendly ultrasound-assisted hot water method for Imperata cylindrica polysaccharide (ICPs) extraction was developed. According to the response surface results, the optimal ultrasonic time was 85 min, ultrasonic power was 192.75 W, temperature was 90.74 °C, liquid-solid ratio was 26.1, and polysaccharide yield was 28.50 %. The polysaccharide mainly consisted of arabinose (Ara), galactose (Gal), and glucose (Glc), with a molecular weight of 62.3 kDa. Ultrasound-assisted extraction of Imperata cylindrica polysaccharide (UICP) exhibited stronger anti-oxidant activity and ability to ameliorate cellular damage due to uric acid stimulation compared with traditional hot water extraction of Imperata cylindrica polysaccharide (ICPC-b). It also exhibited higher thermal stability, indicating its potential value for applications in the food industry.

Intermolecular Carbophosphination of Alkynes with Phosphole Oxides via Ni-Al Bimetal-Catalyzed C-P Bond Activation.

Intermolecular carbophosphination reaction of alkynes or alkenes with unreactive C-P bonds remains an elusive challenge. Herein, we used a Ni-Al bimetallic catalyst to realize an intermolecular carbophosphination reaction of alkynes with 5-membered phosphole oxides, providing a series of 7-membered phosphepines in up to 94 % yield.

Catalyst-Controlled Nickel-Catalyzed Intramolecular endo-Selective C-H Cyclization of Benzimidazoles with Alkenes.

Compared with the widely explored exo-selective C-H cyclization, transition metal-catalyzed endo-selective C-H cyclization of benzimidazoles with alkenes has been a formidable challenge. Previous efforts mainly rely on substrate-controlled methods, rendering the product complexity restricted. Herein we report a catalyst-controlled method to facilitate endo-cyclization, in which a bulky N-heterocyclic carbene ligand and tBuOK base-enabled Ni-Al bimetallic catalyst prove critical to the endo selectivity.

Extraction of anthocyanins from haskap using cold plasma-assisted enzyme.

BACKGROUND: Haskap berries (Lonicera caerulea L.) are rich in anthocyanins. Cold plasma-assisted enzyme method (CPEM) is an innovative method for green extraction of anthocyanins, which was optimized by an artificial neural network-genetic algorithm (ANN-GA) to maximize the yield. In this study, seven factors were screened using by Plackett-Burman design based on single-factor experiments and optimized by ANN-GA. RESULTS: The results showed that the maximum total anthocyanin content (TAC, 42.45 ± 0.25 g cyanidin-3-glucoside equivalent (C3G) kg-1 dry weight, DW) was obtained under optimal pretreatment power of 192 W, pretreatment time of 29 s and liquid-to-solid ratio of 39 mL g-1 . Cleavage and porosity appeared on the surface of the treated sample. The active ingredients and antioxidant capacity of the CPEM extracts were identified by ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Compared with other extraction technologies, CPEM presents the advantages of shortening the extraction time, reducing the solvent volume, and significantly increasing active ingredients and antioxidant activity. CONCLUSION: The ANN-GA has better predictive and higher accuracy than the response surface methodology (RSM) model and is more suitable for optimizing the CPEM by greatly improving the process yield and the utilization of biomass, thus contributing to the sustainability of the agri-food chain. © 2022 Society of Chemical Industry.

Ni-catalyzed benzylic ß-C(sp3)-H bond activation of formamides.

The development of transition metal-catalyzed ß-C-H bond activation via highly-strained 4-membered metallacycles has been a formidable task. So far, only scarce examples have been reported to undergo ß-C-H bond activation via 4-membered metallacycles, and all of them rely on precious metals. In contrast, earth-abundant and inexpensive 3d transition metal-catalyzed ß-C-H bond activation via 4-membered metallacycles still remains an elusive challenge. Herein, we report a phosphine oxide-ligated Ni-Al bimetallic catalyst to activate secondary benzylic C(sp3)-H bonds of formamides via 4-membered nickelacycles, providing a series of α,ß-unsaturated γ-lactams in up to 97% yield.

Enantioselective C2-H Alkylation of Pyridines with 1,3-Dienes via Ni-Al Bimetallic Catalysis.

A chiral phosphine oxide-ligated Ni-Al bimetallic catalyst was used to realize an enantioselective C2-H alkylation of pyridines without the need of a C2-block. A wide range of pyridines, including unsubstituted pyridine, C3, C4, and C2-substituted pyridines, and even complex pyridine-containing bioactive molecules are well compatible with the reaction, providing up to 81% yield and up to 97% ee.

Enantioselective Nickel-Catalyzed C(sp3 )-H Activation of Formamides.

Enantioselective Ni-catalyzed C(sp3 )-H bond activation remains an elusive challenge. Herein, we used phosphine oxide-ligated Ni-Al bimetallic catalyst to realize enantioselective Ni-catalyzed aliphatic C(sp3 )-H activation of formamides, providing a series of chiral N-containing heterocycles in 40-95 % yield and 70-95 % ee.

The complete chloroplast genome of Pinus densata.

Here, we report the complete chloroplast (cp) genome of Pinus densata. The complete chloroplast genome is 119,617 bp in length. There were 112 genes in the genome, including 73 protein-coding genes, 35 tRNA genes, and 4 rRNA genes. The overall GC was 38.5%, and the base of A, C, G, and T were 30.6, 19.3, 19.2, and 30.9%, respectively. Phylogenetic analysis showed that P. densata was relatively closely related to Pinus tabuliformis. These data may providing useful information for the phyletic evolution of P. densata within the Pinaceae family.

A directive Ni catalyst overrides conventional site selectivity in pyridine C-H alkenylation.

Achieving the transition metal-catalysed pyridine C3-H alkenylation, with pyridine as the limiting reagent, has remained a long-standing challenge. Previously, we disclosed that the use of strong coordinating bidentate ligands can overcome catalyst deactivation and provide Pd-catalysed C3 alkenylation of pyridines. However, this strategy proved ineffective when using pyridine as the limiting reagent, as it required large excesses and high concentrations to achieve reasonable yields, which rendered it inapplicable to complex pyridines prevalent in bioactive molecules. Here we report that a bifunctional N-heterocyclic carbene-ligated Ni-Al catalyst can smoothly furnish C3-H alkenylation of pyridines. This method overrides the intrinsic C2 and/or C4 selectivity, and provides a series of C3-alkenylated pyridines in 43-99% yields and up to 98:2 C3 selectivity. This method not only allows a variety of pyridine and heteroarene substrates to be used as the limiting reagent, but is also effective for the late-stage C3 alkenylation of diverse complex pyridine motifs in bioactive molecules.

The complete chloroplast genome of a Cladrastis yunchunii X.W.Li et G.S.

Cladrastis yunchunii X.W.Li et G.S is a plant species belonged to the family Papilionaceae. Cladrastis yunchunii is currently found in broad-leaved forests in the limestone area of Luxi County, Yunnan Province. It is suitable for afforestation and urban greening in limestone areas. In this study, for the first time, we report the complete chloroplast genome sequence of C. yunchunii. We sequenced and assembled the entire chloroplast genome of C. yunchuniii. The chloroplast genome was determined to be 158,250 bp in length. It contained large single-copy (LSC) and small single-copy (SSC) regions of 84,930 bp and 12,664 bp, respectively, which were separated by a pair of inverted repeats (IR) regions of 30,328 bp. The genome contained 132 genes, including 87 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. The overall GC content of the whole genome is 38.1%, and the corresponding values of the LSC, SSC, and IR regions were 36.4%, 33.6%, and 41.3%, respectively. Phylogenetic analysis suggested that C. yunchunii is closely related to the genus Ormosia in the Papilionaceae.

The complete chloroplast genome of Keteleeria evelyniana.

Here, we report the complete chloroplast genome of Keteleeria evelyniana. The genome is 116,940 bp in size, which is comprised of a large single-copy (LSC) region of 74,075 bp, a small single-copy (SSC) region of 40,425 bp, and two short inverted repeat (IR) regions of 1,220 bp. The overall GC content of the plastome was 38.5%. The new sequence comprised 103 unique genes, including 74 protein-coding genes, 4 rRNA genes, and 25 tRNA genes. Phylogenetic analysis showed that K.evelyniana was close to Keteleeria hainanensis and Keteleeria davidiana.

Ni-Catalyzed Dual C-H Annulation of Benzimidazoles with Alkynes for Synthesis of π-Extended Heteroarenes.

Transition metal catalyzed dual C-H activation and annulation with alkynes was an attractive protocol to construct polycyclic π-extended structures. However, most of them were dominated by noble metal catalysts. Disclosed herein was the study of base-metal Ni-catalysis for dual C-H annulation of N-aromatic imidazole, which produced a range of desired polycyclic aza-quinolines in 48-95% yields. The use of bifunctional phosphine oxide ligand proved to be critical for success.

Construction 7-membered ring via Ni-Al bimetal-enabled C-H cyclization for synthesis of tricyclic imidazoles.

The construction of 7-membered ring via direct C7-H cyclization of benzoimidazoles with alkenes would provide a more atom- and step-economical route to tricyclic imidazoles and derivatives that widely exist in a broad range of bioactive molecules. However, transition metal-catalyzed C-H cyclization for medium-ring synthesis has been limited to reactive C-H bonds, instead, the activation of unreactive C-H bonds towards medium synthesis still remains an elusive challenge. Herein, we report a direct construction of 7-membered rings via Ni-Al co-catalyzed unreactive C7-H cyclization of benzoimidazoles with alkenes, providing a series of tricyclic imidazoles in 40-98% yield and with up to 95:5 er.

Brønsted Acid Enabled Nickel-Catalyzed Hydroalkenylation of Aldehydes with Styrene and its Derivatives.

A Brønsted acid enabled nickel-catalyzed hydroalkenylation of aldehydes and styrene derivatives has been developed. The Brønsted acid acts as a proton shuttle to transfer a proton from the alkene to the aldehyde, thereby leading to an economical and byproduct-free coupling. A series of synthetically useful allylic alcohols were obtained through one-step reactions from readily available styrene derivatives and aliphatic aldehydes in up to 88 % yield and with high linear selectivity.

Ni-Al Bimetallic Catalyzed Enantioselective Cycloaddition of Cyclopropyl Carboxamide with Alkyne.

A Ni-Al bimetallic catalyzed enantioselective cycloaddition reaction of cyclopropyl carboxamides with alkynes has been developed. A series of cyclopentenyl carboxamides were obtained in up to 99% yield and 94% ee. The bifunctional-ligand-enabled bimetallic catalysis proved to be an efficient strategy for the C-C bond cleavage of unreactive cyclopropanes.