Microplastics removal mechanisms in constructed wetlands and their impacts on nutrient (nitrogen, phosphorus and carbon) removal: A critical review.

Microplastics (MPs) are now prevalent in aquatic ecosystems, prompting the use of constructed wetlands (CWs) for remediation. However, the interaction between MPs and CWs, including removal efficiency, mechanisms, and impacts, remains a subject requiring significant investigation. This review investigates the removal of MPs in CWs and assesses their impact on the removal of carbon, nitrogen, and phosphorus. The analysis identifies crucial factors influencing the removal of MPs, with substrate particle size and CWs structure playing key roles. The review highlights substrate retention as the primary mechanism for MP removal. MPs hinder plant nitrogen uptake, microbial growth, community composition, and nitrogen-related enzymes, reducing nitrogen removal in CWs. For phosphorus and carbon removal, adverse effects of MPs on phosphorus elimination are observed, while their impact on carbon removal is minimal. Further research is needed to understand their influence fully. In summary, CWs are a promising option for treating MPs-contaminated wastewater, but the intricate relationship between MPs and CWs necessitates ongoing research to comprehend their dynamics and potential consequences.

Streamlined Catalytic Enantioselective Synthesis of α-Substituted ß,γ-Unsaturated Ketones and Either of the Corresponding Tertiary Homoallylic Alcohol Diastereomers.

A widely applicable, practical, and scalable strategy for efficient and enantioselective synthesis of ß,γ-unsaturated ketones that contain an α-stereogenic center is disclosed. Accordingly, aryl, heteroaryl, alkynyl, alkenyl, allyl, or alkyl ketones that contain an α-stereogenic carbon with an alkyl, an aryl, a benzyloxy, or a siloxy moiety can be generated from readily available starting materials and by the use of commercially available chiral ligands in 52-96% yield and 93:7 to >99:1 enantiomeric ratio. To develop the new method, conditions were identified so that high enantioselectivity would be attained and the resulting α-substituted NH-ketimines, wherein there is strong C═N → B(pin) coordination, would not epimerize before conversion to the derived ketone by hydrolysis. It is demonstrated that the ketone products can be converted to an assortment of homoallylic tertiary alcohols in 70-96% yield and 92:8 to >98:2 dr-in either diastereomeric form-by reactions with alkyl-, aryl-, heteroaryl-, allyl-, vinyl-, alkynyl-, or propargyl-metal reagents. The utility of the approach is highlighted through transformations that furnish other desirable derivatives and a concise synthesis route affording more than a gram of a major fragment of anti-HIV agents rubriflordilactones A and B and a specific stereoisomeric analogue.

An efficient and adaptive data-hiding scheme based on secure random matrix.

There is a vivid research on securely deliver a secret message by using a data hiding technique in digital images. However, most existing solutions of data-hiding need to encrypt secret data first, and embed the encrypt message into cover image, which is not promising any security once the embedding algorithm is leaked. In this paper, an efficient and adaptive data hiding scheme is presented which is based on a new reference matrix named secure reference matrix. The scheme is flexible enough to meet different data hiding capacities and image quality as needed, and we allow the reference matrix to be more secure since it is randomly generated each time and make it much harder for being attack with exhaustive manner by extending the possible solution. We give the detail protocol for our scheme and provide the practical test and performance analysis. Experimental results show that our scheme has a better flexibility and efficiency in embedding process, and the average value of Peak Signal to Noise Ratio (PSNR) for the stego-images which are generated by our scheme have a higher visual quality for different embedding capacities, and our scheme is more efficient compared with related work.

Delayed catalyst function enables direct enantioselective conversion of nitriles to NH2-amines.

Accessing enantiomerically enriched amines often demands oxidation-state adjustments, protection and deprotection processes, and purification procedures that increase cost and waste, limiting applicability. When diastereomers can be formed, one isomer is attainable. Here, we show that nitriles, largely viewed as insufficiently reactive, can be transformed directly to multifunctional unprotected homoallylic amines by enantioselective addition of a carbon-based nucleophile and diastereodivergent reduction of the resulting ketimine. Successful implementation requires that competing copper-based catalysts be present simultaneously and that the slower-forming and less reactive one engages first. This challenge was addressed by incorporation of a nonproductive side cycle, fueled selectively by inexpensive additives, to delay the function of the more active catalyst. The utility of this approach is highlighted by its application to the efficient preparation of the anticancer agent (+)-tangutorine.

Expression and clinical significance of PD-1 /PD-L1 in gastric cancer tissues / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate the expression and clinical significance of PD-1/PD-L1 in gastric cancer (GC) tissues. Methods: Paraffin embedded tumor tissues and clinical data of 82 GC patients who had undergone operation at the Fourth Hospital of Hebei Medical University from January 2007 to December 2007 were collected, and their survival status was followed. The protein expressions of PD-1 and PD-L1 in tumor tissues were detected by immunohistochemistry. Kaplan-Meier analysis and Log-Rank test were adopted to analyze the survival of GC patients, and the ROC curve was plotted. Results: The positive rate of PD-L1 protein expression was 42.68% while the positive rate of PD-1 expression was 13.41% in GC tissues. The positive rate of PD-1 and PD-L1 expression in GC tissues of patients without pre-operative distant metastasis was significantly lower than those patients with pre-operative metastasis (PD1： 3.28% vs 42.86%; PD-L1： 13.11% vs 90.48%; all P<0.01). The positive rate of PD-L1 expression in tumor stroma of patients without pre-operative distant metastasis was significantly lower than those with metastasis (PD-L1: 13.11% v s 47.62%, P<0.01). The resection range of stomach, PD-L1 over-expression and the presence of pre-operative distant metastasis were the adverse factors affecting the prognosis of patients with GC (P<0.05). Conclusion: PD-1 and PD-L1 expressions in GC tissues were closely related to the presence of pre-operative distant metastasis and the depth of tumor infiltration. The postoperative survival of patients who were PD-L1 positive was shorter than the negative ones.

Three-dimensional periodic supramolecular organic framework ion sponge in water and microcrystals.

Self-assembly has emerged as a powerful approach to generating complex supramolecular architectures. Despite there being many crystalline frameworks reported in the solid state, the construction of highly soluble periodic supramolecular networks in a three-dimensional space is still a challenge. Here we demonstrate that the encapsulation motif, which involves the dimerization of two aromatic units within cucurbit[8]uril, can be used to direct the co-assembly of a tetratopic molecular block and cucurbit[8]uril into a periodic three-dimensional supramolecular organic framework in water. The periodicity of the supramolecular organic framework is supported by solution-phase small-angle X-ray-scattering and diffraction experiments. Upon evaporating the solvent, the periodicity of the framework is maintained in porous microcrystals. As a supramolecular 'ion sponge', the framework can absorb different kinds of anionic guests, including drugs, in both water and microcrystals, and drugs absorbed in microcrystals can be released to water with selectivity.