Design and application of weight gain graphs based on Bandura’s self-efficacy theory for patients on maintenance haemodialysis

Purpose:To design interdialytic and daily weight gain graphs for patients on maintenance haemodialysis and to evaluate their effect on patient adherence to restricted fluid intake.Methods:Forty-five patients on maintenance haemodialysis were recruited from August to October 2012.The graphs were applied for 12 weeks based on Bandura’s self-efficacy theory.Adherence to restricted fluid intake,dialysis adequacy,and satisfaction were compared before and after the graphs were applied.Results:Adherence to restricted fluid intake increased from 53.3%to 91.1%;the mean rate of urea clearance(Kt/V)decreased from 1.197 to 1.311,and the qualified rate increased from 42.5%to 70%.The rate of adherence was 86.77%;acceptance and satisfaction rates were 100%.Conclusion:It is acceptable to apply the graphs clinically for subsequent effective improvement of adherence to restricted fluid intake,promoting dialysis adequacy,and increasing patient satisfaction.Therefore,clinical application of the graphs is worthwhile.

席夫碱法制备大孔聚合物肝素亲和层析介质

肝素亲和层析介质因其专一性好、操作条件温和等特点,广泛应用于蛋白分离纯化,本工作以大孔聚丙烯酸酯微球为基质,肝素为配基,利用席夫碱法制备了肝素亲和层析介质。配基偶联经过三步完成,首先将大孔聚丙烯酸酯微球表面环氧基团通过0.5 mol/L H_(2)SO_(4)水解为邻羟基,然后将邻羟基氧化为醛基,最后利用醛基与肝素分子的胺基反应将肝素分子固定于微球表面。以溶菌酶为模型蛋白,主要考察了肝素偶联反应的各因素对蛋白结合容量的影响规律,包括肝素浓度、缓冲液pH及浓度、反应时间等,建立了最优偶联肝素配基的方法。所得亲和介质静态结合容量可达40.3 mg/mL,比商品GP-肝素介质高约36%,经1.0 mol/L的氯化钠洗脱,其蛋白回收率达到95%。通过扫描电子显微镜表征微球表面形貌,观察到偶联肝素后的微球仍能保持其大孔结构。考察了该类亲和介质在不同操作流速(31.8~318 cm/h)下的动态结合容量,发现操作流速提高10倍后介质结合容量仅下降12%。经10次重复使用后,动态结合容量仍可保持初始容量的81%。用于混合蛋白模型中分离乳铁蛋白,结果表明具有良好的分离效果。

Application of artificial intelligence in diagnosis of pulmonary tuberculosis

Tuberculosis(TB)is an infectious disease caused by Mycobacterium tuberculosis.Although the diagnostic technology of pulmonary tuberculosis(PTB)has advanced,accurate and differential diagnoses of PTB are still challenging.In recent years,the rapid development of artificial intelligence(AI)and its wide application in the medical field have provided new opportunities for diagnosing and treating TB and PTB.The machine learning model of AI has not only helped physicians improve diagnostic accuracy,but also enabled them to make early preventive diagnoses for individuals at increased risk of infection.Furthermore,AI can guide physicians to formulate targeted treatment strategies for PTB patients with different conditions.

Crown ether-assisted room-temperature halide passivation for highefficiency PbS quantum dots enabling large-area and long-lifetime near-infrared QD-OLEDs

High-efficiency and low-cost near-infrared(NIR)emitting quantum dots(QDs)are highly desirable for next-generation intrinsically flexible NIR light sources.Halide passivation is commonly employed to passivate surface traps to obtain high-quality NIRemitting PbS QDs,but this procedure requires high temperature and inert atmospheres.Here we develop a facile roomtemperature halide passivation method for highly efficient NIR-emitting PbS QDs by employing crown ethers as a unique auxiliary additive.Experimental and theoretical investigations reveal that the formation of K^(+)-crown ethers complex effectively facilitates the dissociation of KCl in toluene and releases more Cl^(−)ions for extraordinary halide passivation at room temperature and in the air,thus improving the photoluminescence quantum yield from 24%to 35%in solution and further to 44%in blend films.The well-passivated PbS QD films are integrated with red organic light-emitting diodes(OLEDs)and the resulting QDOLEDs exhibit high-performance NIR emission centered at 887 nm,a high external quantum efficiency of 5.2%at a radiance of 10 W·sr^(−1)·m^(−2),superior operational stability with long lifetime T90 of 188 h at the current density of 25 mA·cm^(−2).We also construct a large-area NIR QD-OLED(5 cm×5 cm)with desirable uniform emission.This work opens a new avenue to achieve robust large-area NIR planar light sources for broad applications.

刺激-响应型蛋白质分子印迹材料的研究进展

蛋白质分子印迹技术在蛋白组学、生命科学、生物传感、药学研究及生物样品纯化等领域具有广泛的应用价值并备受关注.不过,由于其分子量较大,蛋白质分子印迹材料在应用中还存在蛋白质的传输扩散效率较低及吸附脱附较难等缺陷.而新出现的刺激-响应型蛋白质分子印迹材料可对外界刺激做出反应,并可进一步通过调控分子印迹材料与生物大分子之间的相互作用来实现目标蛋白质的高效快速捕获及释放,因此其具有重要的应用前景.本文综述了近20年来刺激-响应型蛋白质分子印迹材料的研究进展,并概述了其制备方法、聚合物单体种类、刺激-响应类型及机理,还进一步阐明了刺激-响应型蛋白质分子印迹技术的未来发展方向.

养殖废弃物治理经济绩效及其影响因素——基于北京市养殖场(户)视角

养殖废弃物污染严重危害农村环境,但养殖场(户)往往缺乏养殖废弃物治理的积极性,而提高养殖废弃物治理经济绩效会大大提高养殖场(户)的治理积极性,这使得充分了解养殖场(户)的废弃物治理经济绩效及其影响因素显得尤为重要。本文运用DEA-Tobit两阶段模型分析北京市2017年调研数据,对养殖废弃物治理经济绩效进行测算并分析影响因素。研究发现:技术、管理及规模化对养殖废弃物治理的经济绩效有很强的促进作用,且技术与管理的促进作用大于规模化;养殖场(户)负责人偏好经营风险、养殖时间长、选择干清粪进一步选择机械干清、环评意愿强、周边农户施用粪肥积极性高对养殖废弃物治理经济绩效有显著正向影响,养殖场(户)愿意在适量的基础上进一步减少使用抗生素、约束类政策认知水平高对养殖废弃物治理经济绩效有显著负向影响;环境绩效高的养殖废弃物治理行为直接拉低其经济绩效,但能通过稳定社会关系对养殖废弃物治理经济绩效有促进作用。本文结论对提高养殖场(户)的治理积极性,进而提高养殖废弃物治理的环境与社会绩效,促进农业可持续发展具有一定理论和现实意义。

Construction of OVA-stabilized fluorescent gold nanoclusters for sensing glucose

Protein protected gold nanoclusters have outstanding physical and chemical properties that make them excellent scaffolds for the construction of novel chemical and biological probes. In this study, a simple one-pot synthesis method was proposed for the preparation of fluorescent probes based on ovalbumin-stabilized gold nanoclusters. This strategy allowed the generation of water-soluble gold nanoclusters within 5 min. The as-prepared fluorescent probe exhibited a red fluorescence emission at 625 nm, and good thermostability. The fluorescent probe was applied to measure glucose concentrations based on the hydrogen peroxide-induced fluorescence quenching principle, and showed favorable biocompatibility, high sensitivity and good selectivity. As a result of the advantageous properties and performance of this fluorescent probe, the present assay allowed for the selective determination of glucose in the range of 5.0×10-6 to 10.0×10-3 mol/L with a detection limit of 1.0×10?6 mol/L. Moreover, the glucose content in urinary samples was analyzed using the constructed fluorescent probe: this indicated the potential of the fluorescent gold nanoclusters for applications in biological and clinical diagnosis and therapy.

Green synthesis of gold nanoclusters using papayajuice for detection of L-lysine

Gold nanoclusters were rapid synthesized within 3 min at 120 ℃ by using papaya juice as a capping and reducing agent(P-AuNCs). The properties of the fluorescent probe were characterized by fluorescent spectroscopy, UV-vis spectroscopy, dynamic light scattering and transmission electron microscope.Based on the surface electron density increase-induced fluorescence enhancing principle, a high selective method for detection of L-lysine was developed with the as-prepared P-AuNCs coupling the fluorescence emission at 440 nm. The fluorescent probe showed high stability and good biocompatibility. Its fluorescence intensity was found to be linearly dependent on the L-lysine concentration in the range of 10.0μmol/L to 1000.0 μmol/L(R^2=0.969) with a limit of detection of 6.0μmol/L. Furthermore, the PAuNCs based approach was applied for monitoring the urine L-lysine contents, demonstrating great potential of fluorescent probes in real samples analysis.

Fluorescent polymer-modified gold nanobipyramids for temperature sensing during photothermal therapy in living cells

The temperature monitoring of treated cancer cells is critical in photothermal therapy.Current methods of detecting intracellular temperatures have low accuracy and poor spatial resolution,which limits their application to photothermal therapy.Herein,a strategy for targeted recognition and selective capture of MCF-7 breast cancer cells based on fluorescent polymer poly(N-isopropylacrylamide-benzoxadiazole-2-vinyl-4,4-dimethyl azlactone,PNMV)and modified gold nanobipyramids(Au NBPs-PNMV)was developed for temperature sensing during photothermal therapy.A mucin-1 protein aptamer(Apt)was applied to selectively target mucin-1 protein overexpressed on the surfaces of the MCF-7 cells,which can reduce interference by affinity interaction between the Apt and proteins.During photothermal therapy,the significant Au NBPs photothermal effect increases the fluorescence intensity of PNMV with temperature.Irradiation of MCF-7 cells cultured with Au NBPs-PNMV@Apt by an 808 nm laser increases the temperature of the system,while the cells can be inactivated because of the remarkable Au NBPs-PNMV@Apt photothermal effect.The results indicate that variation in the fluorescence of Au NBPs-PNMV@Apt can be applied as thermometers to monitor the intracellular effect of photothermal therapy.

Intermolecular charge-transfer aggregates enable high-efficiency near-infrared emissions by nonadiabatic coupling suppression

Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(k_(nr)) governed by the energy gap law. To date, reported endeavors to decelerate k_(nr) are mainly focused on reducing the electron-vibration coupling with the electronic nonadiabatic coupling assumed as a constant. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer(CT) aggregates(CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states;thereby, not only reducing the electronic nonadiabatic coupling and contributing to small k_(nr) for high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for highefficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.

Ovalbumin-stabilized gold nanoclusters with ascorbic acid as reducing agent for detection of serum copper

Ovalbumin-stabilized gold nanoclusters （OVA@AuNCs） were prepared with ascorbic acid as a reducing agent. This strategy could realize the synthesis of water-soluble OVA@AuNCs within 20 min. The asprepared fluorescent probe showed a red fluorescence emission at 630 nm. Moreover, the properties of the OVA@AuNCs were characterized by transmission electron microscope, dynamic light scattering, ultraviolet-visible spectroscopy, fluorescent spectroscopy. Based on the surface electron density decrease-induced fluorescence quenching mechanism, the OVA@AuNCs provided high sensitivity and selectivity for sensing copper ions. A good linear relationship was obtained between the fluorescence intensity of OVA@AuNCs and the concentration of copper ions in the range of 5.0-100.0pumol/L （R2z0.999） with a detection limit of 640 nmol/L. Furthermore, the rat serum copper contents were determined by using the OVA@AuNCs based assay, indicating great potential of fluorescent probes for application in biological and clinical analysis.

_D-Proline capped gold nanoclusters for turn-on detection of serum Raltitrexed

With _D-proline as the reducing and capping agent, fluorescent gold nanoclusters were rapidly prepared(_D-Pro@AuNCs) within 10 min at 100℃. In the present of gold nanoparticles, the fluorescence of _DPro@AuNCs was remarkably quenched. Interestingly, based on the electrostatic interaction between anticancer drug Raltitrexed and gold nanoparticles induced fluorescence "turn-on" principle, a high selective assay for detection of Raltitrexed was established with the probe associating the fluorescence emission at 435 nm. The fluorescence intensity of _D-Pro@AuNCs linearly correlated with the concentration of Raltitrexed in the range from 5.0 mmol/L to 40.0 mmol/L(R^2= 0.999) and the limit of detection was 1.9 mmol/L. Further, after Raltitrexed was abdominal injected in rats, a metabolic approach was constructed with the prepared fluorescent probe. It showed great potential of AuNCs-based sensing probes for application in analysis of serum anticancer drugs.

Open tubular capillary electrochromatography with block co-polymer coating for separation of β-lactam antibiotics

A new open-tubular capillary electrochromatography (OT-CEC) method for analysis of β-lactam antibiotics has been developed with unique block co-polymer coating. To obtain the highly ordered block polymer chains, reversible addition fragmentation chain transfer radical polymerization method was used to synthesize poly (maleic anhydride-styrene-N-isopropylacrylamide). The prepared block copolymer coating was characterized with NMR, fourier transform infrared spectroscopy and scanning electron microscope. Several key separation factors of OT-CEC, which including polymer amount,stability of the coating, temperature, species of organic additives, buffer pH and concentration, were investigated in detail. Our results indicated that the separation efficiency was improved greatly with the coating capillary and the three test analytes could be baseline separated. Then, the separation mechanism was briefly explored. Moreover, the proposed OT-CEC method displayed promising quantitative analysis property of the three test analytes with good linearity (R2>0.99), repeatability (relative standard deviations <0.9%) and high recovery (95.4%-106.2%). Further, the assay was applied in monitoring the three test β-lactam antibiotics (cephradine, cephalexin and amoxicillin) in serum samples, providing a useful platform for construction of novel polymer coatings in OT-CEC system and for analysis of drugs in real bio-samples.

Enzyme immobilization on a pH-responsive porous polymer membrane for enzymatic kinetics study

Immobilization of enzymes onto carriers is a rapidly growing research area aimed at increasing the stability,reusability and enzymolysis efficiency of free enzymes.In this work,the role of phaseseparation and a pH-responsive"hairy"brush,which greatly affected the topography of porous polymer membrane enzyme reactors(PMER),was explored.The porous polymer membrane was fabricated by phase-separation of poly(styrene-co-maleic anhydride-acrylic acid)and poly(styrene-ethylene glycol).Notably,the topography and pores size of the PMER could be controlled by phase-separation and a pHresponsive"hairy"brush.For evaluating the enzymolysis efficiency of D-amino acid oxidase(DAAO)immobilized carrier(DAAO@PMER),a chiral ligand exchange capillary electrophoresis method was developed with D-methionine as the substrate.The DAAO@PMER showed good reusability and stability after five continuous runs.Notably,comparing with free DAAO in solution,the DAAO@PMER exhibited a17.7-folds increase in catalytic velocity,which was attributed to its tailorable topography and pHresponsive property.The poly(acrylic acid)moiety of poly(styrene-co-maleic anhydride-acrylic acid)as the pH-responsive"hairy"brush generated topography changing domains upon adjusting the buffer pH,which enable the enzymolysis efficiency of DAAO@PMER to be tuned based upon the well-defined architectures of the PMER.This approach demonstrated that the topographical changes formed by phaseseparation and the pH-responsive"hairy"brush indeed made the proposed porous polymer membrane as suitable supports for enzyme immobilization and fitting for enzymolysis applications,achieving high catalytic performance.

Synthesis of polymer protected Au NPs for silver ions detection

Herein, a novel probe based on poly(N,N′-methylenebisacylamide) protected Au NPs(PDMAM-Au NPs) was developed for determination of silver ions. The thiol-terminated PDMAM was synthesized by the reversible addition fragmentation chain transfer radical polymerization. Then, the PDMAM-Au NPs were prepared by a simple, one-pot and green process. It has been observed that existence of the silver ions evoked a small red-shift to the emission peak of PDMAM-Au NPs and an obvious increase in UV absorption. The detection limit of the present method for silver ions was 0.5 ?mol/L, with a linear range of 1.0–1000 ?mol/L. Moreover, the possible mechanism for enhanced UV absorption intensity with enlarged diameter of PDMAM-Au NPs was explored and discussed briefly. The results demonstrated that silver ions could be detected by the PDMAM-Au NPs based colorimetric assays, further opening up new ways for the visualization and quantification of silver ions involved in our daily life.

Negative Charge Management to Make Fragile Bonds Less Fragile toward Electrons for Robust Organic Optoelectronic Materials

The operational stability of organic(opto)electronic devices largely depends on the intrinsic stability of organic materials on service.For organic light-emitting diode(OLED)materials,a key parameter of their intrinsic stability is the bond-dissociation energy of the most fragile bond(BDE_(f)).Although rarely involved,many OLED molecules have the lowest BDE_(f) in anionic states[BDE_(f)(−)∼1.6–2.5 eV],which could be a fatal short-slab for device stability.Herein,we separated BDE_(f)(−)from other parameters and confirmed the clear relationship between BDE_(f)(−),intrinsic material stability and device lifetime.Based on thermodynamic principles,we developed a general and effective strategy to greatly improve BDE_(f)(−)by introducing a negative charge manager within the molecule.The manager must combine an electron-withdrawing group(EWG)with a delocalizing structure,so that it can firmly confine the negative charge and hinder the charge redistribution toward fragile bonds.Consequently,the use of this manager can substantially promote BDE_(f)(−)by∼1 eV for various fragile bonds and outperform the effect reported from solely employing EWGs or delocalizing structures.This effect was verified in typical phosphine-oxide and carbazole derivatives and backed up by newly designed molecules with multiple fragile bonds.This strategy provides a new way to transform vulnerable building blocks into robust organic(opto)electronic materials and devices.