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Discharging of dewatered dry sludge into the environment can trigger irreversible environmental damage. The treatment of dewatered dry sludge into a valuable biochar product is essential for the sustainability of resources and environmental safety. In this study, we examined the removal of phosphate from water bodies by adsorption of biochar that had been prepared from dewatered dry sludge with different pyrolysis temperatures. We showed that being a composite material rich in carbon, CaO and MgO were produced in the biochar preparation when the pyrolysis temperature was increased to 700 °C. The phosphate adsorption of biochar has strengthened with the increase of pH. The phosphate adsorption of composite was fitted with the pseudo-second-order kinetic model, while the Langmuir adsorption isotherm model yielded a maximum phosphate adsorption of 51.79 mg/g. The phosphate adsorption by sludge biochar was mainly affected by the deposition of phosphate crystals and electrostatic attraction. Overall, biochar prepared from dewatered dry sludge demonstrated acceptable phosphate removal performance and phosphate-loaded biochar had a slow release of phosphorus, therefore, can be used as a phosphate fertilizer to promote plant growth.

The leakage failure of the austenitic stainless steel tubes in the hydrogenation unit of a petrochemical company was analyzed. The causes of the failure were investigated by visual examination, chemical compositions analysis of the tube, microscopic examination, metallographic examination and scale layer analysis. The results showed that the directly reason of the failure is pitting corrosion and stress corrosion cracking. We concluded that the improper heat treatment of the austenitic stainless tubes and existence of the corrosive substances including wet hydrogen sulfide and hydrogen chloride in the working medium, result in the occurrence of the corrosion, and the complex flowing conditions accelerate the corrosion process. Proposals were put forward in this paper.

Antibodies against the receptor-binding-domain of the SARS-CoV-2 spike protein prevent SARS-CoV-2 infection. However, the effects of antibodies against other spike protein domains are largely unknown. Here, we screened a series of anti-spike monoclonal antibodies from COVID-19 patients, and found that some of antibodies against the N-terminal-domain (NTD) induced the open conformation of receptor binding domain (RBD) and thus enhanced the binding capacity of the spike protein to ACE2 and infectivity of SARS-CoV-2. Mutational analysis revealed that all the infectivity-enhancing antibodies recognized a specific site on the NTD. Structural analysis demonstrated that all the infectivity-enhancing antibodies bound to NTD in a similar manner. The antibodies against this infectivity-enhancing site were detected at high levels in severe patients. Moreover, we identified antibodies against the infectivity-enhancing site in uninfected donors, albeit at a lower frequency. These findings demonstrate that not only neutralizing antibodies but also enhancing antibodies are produced during SARS-CoV-2 infection., A subset antibodies that are detected in patients with severe COVID-19 target a specific region of the N terminal domain of the spike protein and enhance binding of the virus to the ACE2 receptor.

The oxidized amyloses with different carboxyl content were prepared to include linalool for antimicrobial activity in aqueous environment. The results show that linalool can be effectively reserved from volatilization through encapsulation into amylose and oxidized amyloses. The inclusion ability of oxidized amyloses towards linalool is decreasing with the increase of oxidation level due to the depolymerization of amylose. However, the solubilization effect of oxidized amyloses to linalool is enhanced efficiently owning to the high water solubility of oxidized amyloses. It is interesting that the inclusion complexes have good antimicrobial activity in aqueous environment. Linalool solubilized by oxidized amyloses presents better antimicrobial performance than that solubilized by amylose, mainly resulting from that amylose-linalool inclusion complex would aggregate and retrograde fast in aqueous solution, which is disadvantageous for the release of linalool. The study suggests that oxidized amylose is a promising solubilizer and carrier of linalool for antimicrobial activity in aqueous environment.

An ultrasensitive electrochemical DNA biosensor has been developed based on the assembly of highly conductive gold nanoparticles (AuNPs) on the free terminal of hairpin-structured probe DNA. The hairpin probe DNA was first immobilized on a gold electrode surface through Au S bond. Then the thioglycolic acid (TGA) was grafted on the 3′-end of hairpin DNA via the carboxylic-amino condensation reaction. Followed by, the AuNPs were further attached through reaction with the thiol-group of TGA. Thus, a highly conductive biointerface with ultralow charge-transfer resistance was obtained. Quantitative analysis exhibited that the target DNA could be detected over the range from 1.0 × 10−17 to 1.0 × 10−11 M. The detection limit was estimated to be 1.7 × 10−18 M. Also the biosensor showed good hybridization selectivity, stability and regeneration ability.

The reaction of [Ag(dppm)(NO 3 ] 2 with sodium phenylacetate and dppm in THF at room temperature gave rise to the silver complexes [Ag(dppm)(O 2 CCH 2 Ph)] 2 ( 1 ) and [Ag 2 (dppm) 3 ](NO 3 ) 2 ( 2 ), respectively. Their crystal structures have been determined by single crystal X-ray diffraction analysis. Complex 1 is binuclear with a silver-silver separation of 3.080 A and bridged by two dppm ligands. The cation in complex 2 possesses a Ag 2 P 6 core with AgAg distance of 2.987 A and the silver atoms are each coordinated by three phosphorus atoms in an ideal trigonal-planar environment. Their IR, Raman, 1 H and 31 P NMR spectroscopic properties are also reported.