Wittig/B─H insertion reaction: A unique access to trisubstituted Z-alkenes.

The Wittig reaction, which is one of the most effective methods for synthesizing alkenes from carbonyl compounds, generally gives thermodynamically stable E-alkenes, and synthesis of trisubstituted Z-alkenes from ketones presents notable challenges. Here, we report what we refer to as Wittig/B─H insertion reactions, which innovatively combine a Wittig reaction with carbene insertion into a B─H bond and constitute a promising method for the synthesis of thermodynamically unstable trisubstituted Z-boryl alkenes. Combined with the easy transformations of boryl group, this methodology provides efficient access to a variety of previously unavailable trisubstituted Z-alkenes and thus provides a platform for discovery of pharmaceuticals. The unique Z-selectivity of the reaction is determined by the maximum overlap of the orbitals between the B─H bond of the borane adduct and the alkylidene carbene intermediate in the transition state.

Single-gene FISH maps and major chromosomal rearrangements in Elymus sibiricus and E. nutans.

BACKGROUND: Chromosomal variations have been revealed in both E. sibiricus and E. nutans, but chromosomal structural variations, such as intra-genome translocations and inversions, are still not recognized due to the cytological limitations of previous studies. Furthermore, the syntenic relationship between both species and wheat chromosomes remains unknown. RESULTS: Fifty-nine single-gene fluorescence in situ hybridization (FISH) probes, including 22 single-gene probes previously mapped on wheat chromosomes and other newly developed probes from the cDNA of Elymus species, were used to characterize the chromosome homoeologous relationship and collinearity of both E. sibiricus and E. nutans with those of wheat. Eight species-specific chromosomal rearrangements (CRs) were exclusively identified in E. sibiricus, including five pericentric inversions in 1H, 2H, 3H, 6H and 2St; one possible pericentric inversion in 5St; one paracentric inversion in 4St; and one reciprocal 4H/6H translocation. Five species-specific CRs were identified in E. nutans, including one possible pericentric inversion in 2Y, three possible pericentric multiple-inversions in 1H, 2H and 4Y, and one reciprocal 4Y/5Y translocation. Polymorphic CRs were detected in three of the six materials in E. sibiricus, which were mainly represented by inter-genomic translocations. More polymorphic CRs were identified in E. nutans, including duplication and insertion, deletion, pericentric inversion, paracentric inversion, and intra- or inter-genomic translocation in different chromosomes. CONCLUSIONS: The study first identified the cross-species homoeology and the syntenic relationship between E. sibiricus, E. nutans and wheat chromosomes. There are distinct different species-specific CRs between E. sibiricus and E. nutans, which may be due to their different polyploidy processes. The frequencies of intra-species polymorphic CRs in E. nutans were higher than that in E. sibiricus. To conclude, the results provide new insights into genome structure and evolution and will facilitate the utilization of germplasm diversity in both E. sibiricus and E. nutans.

Corrigendum to "Cobalt metal-organic framework modified carbon cloth/paper hybrid electrochemical button-sensor for nonenzymatic glucose diagnostics" [Sens. Actuators B Chem. 329 (2021) 129205].

[This corrects the article DOI: 10.1016/j.snb.2020.129205.].

Combined Transcriptome and Proteome Analysis of Maize (Zea mays L.) Reveals A Complementary Profile in Response to Phosphate Deficiency.

A deficiency in the macronutrient phosphate (Pi) brings about various changes in plants at the morphological, physiological and molecular levels. However, the molecular mechanism for regulating Pi homeostasis in response to low-Pi remains poorly understood, particularly in maize (Zea mays L.), which is a staple crop and requires massive amounts of Pi. Therefore, in this study, we performed expression profiling of the shoots and roots of maize seedlings with Pi-tolerant genotype at both the transcriptomic and proteomic levels using RNA sequencing and isobaric tags for relative and absolute quantitation (iTRAQ). We identified 1944 differentially expressed transcripts and 340 differentially expressed proteins under low-Pi conditions. Most of the differentially expressed genes were clustered as regulators, such as transcription factors involved in the Pi signaling pathway at the transcript level. However, the more functional and metabolism-related genes showed expression changes at the protein level. Moreover, under low-Pi conditions, Pi transporters and phosphatases were specifically induced in the roots at both the transcript and protein levels, and increased amounts of mRNA and protein of two purple acid phosphatases (PAPs) and one UDP-sulfoquinovose synthase (SQD) were specifically detected in the roots. The new insights provided by this study will help to improve the P-utilization efficiency of maize.

Comparison of therapeutic effects of different acupuncture and moxibustion therapies on irritable bowel syndrome: A protocol for systematic review and network meta-analysis.

BACKGROUND: Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder with recurrent abdominal pain and changes in bowel habits. Many pieces of evidence show that acupuncture and moxibustion therapy has advantages in the treatment of IBS, but there are many acupuncture and moxibustion therapy options, each of which has different therapeutic effects. This study will evaluate the clinical efficacy of different acupuncture and moxibustion therapies in the treatment of IBS by means of a network meta-analysis. METHODS: According to the retrieval strategy, we retrieved the randomized controlled trials of acupuncture and moxibustion treatment of IBS from China National Knowledge Infrastructure, Wanfang, VIP, Chinese biomedical databases, PubMed, Embase, Web of Science, and the Cochrane Library databases from the database establishment to July 2021. We assessed the quality of the studies using the Cochrane Risk Bias Assessment Tool and assessed the strength of the evidence using the Grading of Recommendation Assessment, Development, and Evaluation methodology. All data analyses were performed by RevMan5.3, Gemtc 0.14.3, and Stata 14.0. RESULTS: This study evaluated the efficacy of different acupuncture and moxibustion therapies in the treatment of IBS by evaluating the clinical efficacy rate, symptom scores, quality of life scores, adverse reactions, etc, and further explore the mechanism of action of each therapy. CONCLUSION: This study will provide a reliable evidence-based basis for selecting the best acupuncture and moxibustion therapy for IBS. ETHICS AND DISSEMINATION: Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval will not be required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/3278Y.

Cobalt metal-organic framework modified carbon cloth/paper hybrid electrochemical button-sensor for nonenzymatic glucose diagnostics.

In the growing pandemic, family healthcare is widely concerned with the increase of medical self-diagnosis away from the hospital. A cobalt metal-organic framework modified carbon cloth/paper (Co-MOF/CC/Paper) hybrid button-sensor was developed as a portable, robust, and user-friendly electrochemical analytical chip for nonenzymatic quantitative detection of glucose. Highly integrated electrochemical analytical chip was successfully fabricated with a flexible Co-MOF/CC sensing interface, effectively increasing the specific area and catalytic sites than the traditional plane electrode. Based on the button-sensor, rapid quantitative detection of glucose was achieved in multiple complex bio-matrixes, such as serum, urine, and saliva, with desired selectivity, stability, and durability. With the advantages of low cost, high environment tolerance, ease of production, our nanozyme-based electrochemical analytical chip achieved reliable nonenzymatic electrocatalysis, has great potential for the application of rapid on-site analysis in personalized diagnostic and disease prevention.

Gold nanodendrite-based differential potential ratiometric sensing strategy for enantioselective recognition of DOPA.

Numerous chiral drugs have been developed for neurological diseases, but chiral drug safety and pharmacological research still faces great challenges in enantioselectivity and sensitivity of chiral analysis. A rapid, stable and high-efficiency gold nanodendrite-based electrochemical sensing method was proposed as a versatile differential potential ratiometric strategy for highly selective chiral recognition of dual 3,4-dihydroxyphenylalanine (DOPA) enantiomers. Using simple electrochemical deposition, the gold nanodendrite (AuND) membrane was steadily modified on the glassy carbon electrode (GCE) with high specific chiral identifiability and robust signal amplifiability. Based on a sequence of systematic optimization, an apparent potential difference (PD) was detected up to 108 mV from oxidation peaks of DOPA enantiomers. Furthermore, according to a regulatable concentration range from 10 µM to 100 µM, different proportions of L-/d-DOPA had a good linear relationship with corresponding peak potentials (Eps) in the racemic mixture. Superior to traditional enantiorecognition of single chiral drug, both DOPA enantiomers enabled to be simultaneously distinguished with high repeatability, selectivity, and anti-interference ability on the AuND/GCE. This unique semi-quantitative AuND-based potential sensing strategy was proposed to efficiently quantify the proportion of L-/d-DOPA for chiral drug recognition, emerging positive potential for numerous applications in pharmacology and clinical diagnosis.

Enhanced adsorption of ciprofloxacin by KOH modified biochar derived from potato stems and leaves.

Potato stems and leaves biochar (PB) was prepared by pyrolysis at a temperature of 500°C under anoxic conditions. In order to strengthen the adsorption capacity, biochar was modified with alkaline solution (alkali modified biochar, APB). Two kinds of biochars were adopted as adsorbents to remove ciprofloxacin (CIP) from aqueous solution. The adsorption behavior of CIP onto biochar before and after alkali modified including adsorption kinetics and isotherms were investigated. The effects of different factors (equilibrium time, pH, temperature and initial concentration) during the adsorption process were also investigated. Biochar samples were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherm. The results showed that the alkali treated biochar possessed more mesopores than raw biochar, and accordingly exhibited a more excellent adsorption performance (23.36 mg·g-1) than raw biochar. Hydrophobic interaction, hydrogen-bonding interaction, electrostatic interaction, and π - π interaction were the adsorption mechanisms for CIP uptake onto the two adsorbents.

TiO2 supported on reed straw biochar as an adsorptive and photocatalytic composite for the efficient degradation of sulfamethoxazole in aqueous matrices.

Heterogeneous photocatalysis namely titanium dioxide supported on reed straw biochar (acid pre-treated) (TiO2/pBC) was synthesized by sol-gel method. The morphology, surface area and structure of TiO2/pBC were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD). Low calcination condition maintained the structure of biochar completely and prevented the agglomeration of TiO2 particles. Due to the combination of adsorption and photocatalysis, TiO2/pBC performed higher removal efficiency of sulfamethoxazole (SMX) than pure TiO2 powder under UV light irradiation. The photocatalytic degradation (PCD) of SMX was also studied with the water collected from the Yellow River. Three high concentration inorganic anions (Cl-, NO3-, SO42-) of the river exerted certain degree of detrimental effects on the contaminant degradation. TiO2/pBC showed stable photocatalytic activity after five sequential PCD cycles. The biochar was able to promote further PCD on TiO2 by adsorbing SMX and intermediates thereby prolonging the separation lifetime of electrons (e-) and valence band hole (h+). The transformation intermediates of SMX were identified and three possible degradation reactions of hydroxylation, opening of isoxazole ring and cleavage of SN bond might occur during the PCD of SMX.