耦合氨氧化和水还原反应实现电化学共合成硝酸盐和氢气

硝酸(HNO_(3))是一种重要的含氮化学品,在肥料、火药及炸药等制造领域有广泛的应用,全球年产量高达5000万公吨.传统的硝酸生产主要通过Ostwald工艺,该工艺需要高温(600-800°C)和高压(4-10 bar)条件,并使用贵金属催化剂(如Pt-Rh合金网),先通过逐步催化氧化Haber-Bosch法制得氨,再进一步生成硝酸和水.该方法能耗高,对化石燃料依赖性强,且会排放温室气体CO_(2).因此,探索在温和条件下高效、环保和可持续地制备硝酸方法具有重要意义.本文设计了一种新型的电化学氨氧化和水还原反应耦合体系,可同时电化学合成硝酸盐和氢气.通过电化学氧化方法原位实现了Cu原子和O原子的可控重组,在不同条件下合成出以Cu_(2)O为主的Cu-OX-PBS催化剂和以Cu O为主的Cu-OX-KOH纳米片阵列催化剂.对比两种催化剂催化氨氧化反应性能发现,CuO是将氨转化为NO_(3)^(–)的主要活性位点.在使用Cu-OX-KOH催化剂进行氨氧化反应时,通过调控氨氧化电位策略可实现八电子转移过程中氨到NO_(3)^(–)的转化.Cu-OX-KOH纳米片阵列催化剂在1.5 Vvs.RHE下合成NOx–的法拉第效率高达98.7%,并且最高产率达到121.0±5.4μmol h^(-1)cm^(-2)(2.1 V vs.RHE);同时,在阴极端连续产生H2时具有97.7%的法拉第效率(1.8 V vs.RHE),从而实现了硝酸盐和氢气的同时高效合成.此外,在经108 h稳定性测试后,该反应体系可收集到0.2 molL–1NOx–产物,且反应后催化剂形貌未发生改变,表明CuO纳米片阵列催化剂具有较高的稳定性和实际应用潜力.通过监测反应体系中NH_(3),NO_(2)^(–),NO_(3)^(–)三种物质随时间的变化情况,考察了氨氧化电合成NO_(3)^(–)的反应过程.结果表明,NO_(2)^(–)是氨氧化到NO_(3)^(–)反应过程中的重要中间体,并且随着反应进行,NO_(2)^(–)最终转化为NO_(3)^(–).为进一步分析反应机理,利用原位红外技术检测重要中间体*NH_(2),*NH,*NO和NO_(2)等的形成,并通过密度泛函理论验证了在CuO催化作用下氨氧化到NO_(3)^(–)是一个逐级脱氢加氧的过程,进而推测出氨氧化到NO_(3)^(–)的八电子反应路径并分析了实验过程中NO_(2)^(–)中间体生成的可能原因.综上所述,本文将氨氧化与电解水巧妙地耦合电化学共合成硝酸盐和氢气,为在温和条件下利用可再生能源实现氨与水共活化及高效转化提供了新思路,并为现场原位生成硝酸和氢气提供了参考.

Repeated methamphetamine exposure decreases plasma brain-derived neurotrophic factor levels in rhesus monkeys

Background Brain-derived neurotrophic factor(BDNF)is known to prevent methamphetamine(METH)-induced neurotoxicity and plays a role in various stages of METH addiction.However,there is a lack of research with longitudinal design on changes in plasma BDNF levels in active METH-dependent individuals.Aims The aim of the study was to investigate changes in BDNF levels during METH self-administration in monkeys.Methods This study measured plasma BDNF levels in three male rhesus monkeys with continuous METH exposure and four male control rhesus monkeys without METH exposure.Changes in plasma BDNF levels were then assessed longitudinally during 40 sessions of METH self-administration in the three monkeys.Results Repeated METH exposure decreased plasma BDNF levels.Additionally,plasma BDNF decreased with long-term rather than short-term accumulation of METH during METH self-administration.Conclusions These findings may indicate that the changes in peripheral BDNF may reflect the quantity of accumulative METH intake during a frequent drug use period.

大剂量“笑气”吸食致神经精神症状1例病例报告（英文）

一氧化二氮,俗称"笑气",已经成为全球第七大滥用药物。"笑气"吸食后影响维生素B12代谢,造成神经损伤,产生显著的精神神经症状。对于这类患者,及时的识别和治疗有助于改善预后。本文报告1例19岁的青年男性,在近半年时间内大剂量吸食"笑气",出现幻听、被害妄想、关系妄想和情绪不稳。同时存在肢体无力,全身"手套-袜套"样痛觉过敏等神经症状。予大剂量维生素B12补充为主的治疗后,患者精神症状改善,神经损害好转,但下肢远端未完全恢复。治疗上,应遵循成瘾综合干预措施,除了及时修复神经损害外,还应增强患者治疗动机,针对复吸诱发因素加强干预,这对患者长期预后及回归社会非常有益。

Aberrant expression of BDNF might serve as a candidate target for cocaine- induced psychosis: insights from bioinformatics analysis and microarray validation

Background Cocaine use disorder(CUD)and associated psychosis are major public health issues worldwide,along with high relapse outcome and limited treatment options.Exploring the molecular mechanisms underlying cocaine-induced psychosis(CIP)could supply integrated insights for understanding the pathogenic mechanism and potential novel therapeutic targets.Aims The aim of the study was to explore common alterations of CUD-schizophrenia target genes and identify core risk genes contributing to CIP through data mining and network pharmacology approach.Methods Target genes of CUD were obtained from GeneCards,Comparative Toxicogenomics Database,Swiss Target Prediction platform and PubChem.Schizophrenia-related target genes were derived from DisGeNET,GeneCards,MalaCards and Online Mendelian Inheritance in Man databases.Then,the overlap genes of these two sets were regarded as risk genes contributing to CIP.Based on these CUD-schizophrenia target genes,functional annotation and pathway analysis were performed using the clusterProfiler package in R.Protein-protein interaction network construction and module detection were performed based on the Search Tool for the Retrieval of Interacting Genes(STRING)database and Cytoscape software.Gene expression datasets GSE54839 and GSE93577 were applied for data validation and diagnostic capacity evaluation of interested hub genes.Results A total of 165 CUD-schizophrenia target genes were obtained.These genes were mainly contributing to chemical synaptic transmission,neuropeptide hormone activity,postsynaptic membrane and neuroactive ligand-receptor interaction pathway.Network analysis and validation analysis indicated that BDNF might serve as an important risk gene in mediating CIP.Conclusions This study generates a holistic view of CIP and provides a basis for the identification of potential CUD-schizophrenia target genes involved in the development of CIP.The abnormal expression of BDNF would be a candidate therapeutic target underlying the pathogenesis of CUD and associated CIP.

Real-Time Visual Tracking with Compact Shape and Color Feature

The colour feature is often used in the object tracking.The tracking methods extract the colour features of the object and the background,and distinguish them by a classifier.However,these existing methods simply use the colour information of the target pixels and do not consider the shape feature of the target,so that the description capability of the feature is weak.Moreover,incorporating shape information often leads to large feature dimension,which is not conducive to real-time object tracking.Recently,the emergence of visual tracking methods based on deep learning has also greatly increased the demand for computing resources of the algorithm.In this paper,we propose a real-time visual tracking method with compact shape and colour feature,which forms low dimensional compact shape and colour feature by fusing the shape and colour characteristics of the candidate object region,and reduces the dimensionality of the combined feature through the Hash function.The structural classification function is trained and updated online with dynamic data flow for adapting to the new frames.Further,the classification and prediction of the object are carried out with structured classification function.The experimental results demonstrate that the proposed tracker performs superiorly against several state-of-the-art algorithms on the challenging benchmark dataset OTB-100 and OTB-13.

Expert consensus on the prevention and treatment of substance use and addictive behaviour-related disorders during the COVID-19 pandemic

In early 2020,the COVID-19 outbreak complicated the diagnosis,treatm ent and rehabilitation of patients with substance use disorders and increased the risks of substance abuse and addictive behaviours,such as online gaming disorders,in the general public.Substance use disorder is a chronic recurrent brain disease characterised by strong cravings,high recurrence rates,and a high proportion of comorbidity of mental and physical disorders.1 Therefore,regular long-term therapeutic interventions are critical to preventing dm g relapses while maintaining withdrawal.

Euphoric effect induced by zolpidem:a case study of magnetoencephalography

Initially,zolpidem,a non-benzodiazepine hypnotic agent,was considered to have fewer adverse reactions than traditional benzodiazepines.However,after zolpidem was approved for medical use,an increasing number of case reports have described abuse or dependence complications.We were especially interested in the cases of dependence that presented a paradoxical‘euphoric’effect of zolpidem.This article reports the case of a female zolpidem-dependent patient who presented with 6 years of daily use of 400-1400 mg of zolpidem.She reported subjective effects of euphoria,intense craving and the inability to stop drug ingestion.Her diagnoses were zolpidem dependence and a depressive episode induced by substance abuse.To explore the neural mechanisms of the euphoric effect caused by high-dose zolpidem,we performed repeated magnetoencephalography(MEG)recordings.Before undergoing detoxification,her MEG results indicated that cerebellar electrical signal activation increased when taking high zolpidem doses.However,the prefrontal and parietal lobes’electrical signal activity showed a tendency to recover to a normal state as the withdrawal time progressed to completion.This case suggests that the cerebellum plays a role in the euphoria induced by high zolpidem doses and provides clues for further research.

Clinical characteristics of hospitalised patients with schizophrenia who were suspected to have coronavirus disease(COVID-19)in Hubei Province,China

Background Since the outbreak of C0VID-19,no data have been available for hospitalised psychiatric patients who are suspected to have COVID-19.We performed a comprehensive investigation of the clinical features of hospitalised patients with schizophrenia with or without suspected COVID-19 in Hubei Province,China.Aim To explore the clinical characteristics of hospitalised patients with schizophrenia with suspected COVID-19 in Hubei Province,China.M ethods 21 hospitalised patients with schizophrenia with suspected COVID-19(COVID-19 suspected group)in the isolation ward of a mental health hospital in Wuhan and 30 hospitalised patients with schizophrenia(clean group)in the general ward of another mental health hospital in Yichang were recruited.We retrospectively reviewed their clinical characteristics,laboratory findings and chest CT results before 21 February 2020.We also compared the emotional and mental symptoms between the two groups.Results Medical records revealed that 21 COVID-19 suspected patients were transferred to the isolation ward between 30 January 2020 and 15 February 2020.The mean age(SD)of COVID-19 suspected patients was 43.1(2.6).12(57.1%)patients showed abnormalities on chest CT before onset of respiratory symptoms.14(66.7%)patients had psychiatric medications adjustment after detection of abnormal chest CT findings.By 21 February,one patient was confirmed to have COVID-19.Even though the remaining 20(95.2%)were negative for at least two reverse transcription PCR tests,11(52.4%)patients met the diagnostic criteria for clinically confirmed cases.Compared with patients in the clean group,patients in the suspected COVID-19 group showed significantly higher stress,depression and anxiety levels and poorer sleep quality.Conclusion Setting up an independent isolation ward for hospitalised psychiatric patients who are suspected to have symptoms of COVID-19 helped control the spread of the epidemic.Patients with schizophrenia suspected to have COVID-19 showed increased stress and mood and sleep disturbances,which should be appropriately managed.

Efficient ammonia electrosynthesis from nitrate via a three-step relay mechanism

Electrocatalytically converting nitrate waste to value-added ammonia(NO3−RR)is beneficial to environmental restoration and an attractive candidate for green ammonia production[1].However,developing NO_(3)^(-)RR in an energy-saving way remains a significant challenge due to the slow kinetics inherent in multi-step electron and proton transfer,making previous investigations for NO_(3)^(-)RR generally operate at a large overpotential(<-0.2 V versus reversible hydrogen electrode(RHE))to achieve optimal efficiency and industrial current for NH3 synthesis[2].

Dose,Plasma Level,and Treatment Outcome Among Methadone Patients in Shanghai,China

Abstract The purpose of this study was to investigate the blood levels of methadone in participants receiving methadone for the treatment of opioid dependence. After stabilization on methadone for four weeks, blood samples from 95 participants were collected between treatment weeks 4 and 12, before and after receiving doses of methadone, and its blood levels were measured. A multiple linear regression model was used to examine the associa- tion between methadone blood levels and the outcomes of methadone maintenance treatment （MMT）. Outcome dif- ferences between participants who had high （≥2） or low （〈2） peak-to-trough ratios were also compared using an independent sample t-test. The blood level of methadone was not correlated with the clinical outcome of MMT with the moderate range of doses given. However, the retention of patients who had a free peak-to-trough ratio 〉2 was significantly poorer than those whose ratio was 〈2. Thus, monitoring plasma methadone levels is unlikely to be effective for guiding dosing decisions in situations where compliance with MMT is already very high or when themethadone dose is no longer the dominant factor in determining the clinical outcome. However, monitoring plasma methadone levels is still helpful for guiding the dosage for patients with a rapid metabolism.

Laser frequency instability of 6×10^-16 using 10-cm-long cavities on a cubic spacer

We demonstrate two ultra-stable laser systems at 1064 nm by independently stabilizing two 10-cm-long Fabry–Pérot cavities.The reference cavities are on a cubic spacer,which is rigidly mounted for both low sensitivity to environmental vibration and ability for transportation.By comparing against an independent ultra-stable laser at 578 nm via an optical frequency comb,the 1064 nm lasers are measured to have frequency instabilities of 6×10^-16 at 1 s averaging time.

Recent genome duplications facilitate the phenotypic diversity of Hb repertoire in the Cyprinidae

Whole-genome duplications(WGDs)are an important contributor to phenotypic innovations in evolutionary history.The diversity of blood oxygen transport traits is the perfect reflection of physiological versatility for evolutionary success among vertebrates.In this study,the evolutionary changes of hemoglobin(Hb)repertoire driven by the recent genome duplications were detected in representative Cyprinidae fish,including eight diploid and four tetraploid species.Comparative genomic analysis revealed a substantial variation in both membership composition and intragenomic organization of Hb genes in these species.Phylogenetic reconstruction analyses were conducted to characterize the evolutionary history of these genes.Data were integrated with the expression profiles of the genes during ontogeny.Our results indicated that genome duplications facilitated the phenotypic diversity of the Hb gene family;each was associated with species-specific changes in gene content via gene loss and fusion after genome duplications.This led to repeated evolutionary transitions in the ontogenic regulation of Hb gene expression.Our results revealed that genome duplications helped to generate phenotypic changes in Cyprinidae Hb systems.

Effect of temperature on the effective thermal conductivity of n-tetradecane-based nanofluids containing copper nanoparticles

Nanofluids were prepared by dispersing Cu nanoparticles （-20nm） in n-tetradecane by a two-step method. The effective thermal conductivity was measured for various nanoparticle volume fractions （0.0001-0.02） and temperatures （306.22-452.66 K）. The experimental data compares well with the Jang and Choi model, The thermal conductivity enhancement was lower above 391.06 K than for that between 306,22 and 360,77 K, The interfacial thermal resistance increased with increasing temperature, The effective thermal conductivity enhancement was greater than that obtained with a more viscous fluid as the base media at 452,66 K because of nanoconvection induced by nanoparticle Brownian motion at high temoerature.

Multi-cavity-stabilized ultrastable laser

We demonstrate a proposal for making an ultrastable laser referenced to a multi-cavity, enabling a lower thermal noise limit due to the averaging effect. In comparison with a single-cavity system, relative frequency instability of the synthesized laser can be improved by a factor of the square root of the cavity number. We perform an experiment to simulate a two-cavity system with two independent ultrastable lasers. Experimental results show that the relative frequency instability(Allan deviation) of the synthesized laser is 5 × 10^(-16), improved by a factor of √2 from a single-cavity-stabilized laser.