Partial oxidation of methane by photocatalysis

Methane chemistry is one of the“Holy Grails of catalysis”.It is highly desirable but challenge to transform methane into value-added chemicals,because of its high C-H bonding energy(435 kJ/mol),lack ofπbonding or unpaired electrons.Currently,commercial methane conversion is usually carried out in harsh conditions with enormous energy input.Photocatalytic partial oxidation of methane to liquid oxygenates(PPOMO)is a future-oriented technology towards realizing high efficiency and high selectivity under mild conditions.The selection of oxidant is crucial to the PPOMO performance.Hence,attentions are paid to the research progress of PPOMO with various oxidants(O_(2),H_(2)O,H_(2)O_(2)and other oxidants).Moreover,the activation of the selected oxidants is also highly emphasized.Meanwhile,we summarized the methane activation mechanisms focusing on the C-H bond that was broken mainly by·OH radical,O-specie or photogenerated hole(h+).Finally,the challenges and prospects in this subject are briefly discussed.

Bioengineering extracellular vesicles as novel nanocarriers towards brain disorders

Despite noteworthy technological progress and promising preclinical trials,brain disorders are still the leading causes of death globally.Extracellular vesicles(EVs),nano-/micro-sized membrane vesicles carrying bioactive molecules,are involved in cellular communication.Based on their unique properties,including superior biocompatibility,non-immunogenicity,and blood-brain barrier(BBB)penetration,EVs can shield their cargos from immune clearance and transport them to specific site,which have attracted increasing interests as novel nanocarriers for brain disorders.However,considering the limitations of native EVs,such as poor encapsulation efficiency,inadequate targeting capability,uncontrolled drug release,and limited production,researchers bioengineer EVs to fully exploit the clinical potential.Herein,this review initially describes the basic properties,biogenesis,and uptake process of EVs from different subtypes.Then,we highlight the application of EVs derived from different sources for personalized therapy and novel strategies to construct bioengineered EVs for enhanced diagnosis and treatment of brain disorders.Besides,it also presents a systematic comparison between EVs and other brain-targeted nanocarriers.Finally,existing challenges and future perspectives of EVs have been discussed,hoping to bolster the research from benchtop to bedside.

Ensemble of single-atom catalysis and defect engineering in Cu_(1)/CeO_(2) nanozymes for tumor therapy

As a class of nanomaterials with natural enzyme-like characteristics, nanozymes have shown their great potential in various applications. Reducible metal oxides featured with defect structures, and single-atom catalysts with isolated metal sites are regarded as two of the most promising nanozymes. However, the strategies to construct highly performed nanozymes by combining these advantages are rarely reported. Herein, we report the coordination-unsaturated single-atomic Cu species supported on sintered CeO_(2), which combines the advantages of defect engineering and single-atom catalysis, exhibiting a largely enhanced peroxidase(POD)-like activity. The high-temperature calcination induces the transformation of inert Cu_(1)O_(4) species into coordination-unsaturated Cu_(1)O_(3) sites. This novel Cu_(1)O_(3) active sites with an unsaturated coordination work as a new type of defect sites to greatly activate the isolated Cu atoms and accelerate the dissociation of H_(2)O_(2) to form hydroxyl radicals(·OH). The obtained nanozyme with a high POD-like activity possesses low cytotoxicity, showing potential applications for the tumor inhibition in vitro and in vivo.

Gather wisdom to overcome barriers:Well-designed nano-drug delivery systems for treating gliomas

Due to the special physiological and pathological characteristics of gliomas,most therapeutic drugs are prevented from entering the brain.To improve the poor prognosis of existing therapies,researchers have been continuously developing non-invasive methods to overcome barriers to gliomas therapy.Although these strategies can be used clinically to overcome the blood-brain barrier(BBB),the accurate delivery of drugs to the glioma lesions cannot be ensured.Nano-drug delivery systems(NDDS)have been widely used for precise drug delivery.In recent years,researchers have gathered their wisdom to overcome barriers,so many well-designed NDDS have performed prominently in preclinical studies.These meticulous designs mainly include cascade passing through BBB and targeting to glioma lesions,drug release in response to the glioma microenvironment,biomimetic delivery systems based on endogenous cells/extracellular vesicles/protein,and carriers created according to the active ingredients of traditional Chinese medicines.We reviewed these well-designed NDDS in detail.Furthermore,we discussed the current ongoing and completed clinical trials of NDDS for gliomas therapy,and analyzed the challenges and trends faced by clinical translation of these well-designed NDDS.

百廿山大,崇实求新:乘风破浪的化学与化工学院

东临黄海,南望泰山.在"十四五"规划的伊始之年,山东大学迎来了120周年华诞.山东大学起源于1901年创办的山东大学堂,是中国第一所按章程办学的大学.学校先后历经了山东大学堂、国立青岛大学、国立山东大学、山东大学以及由原山东大学、山东医科大学、山东工业大学三校合并组建的新山东大学等几个历史发展时期.山东大学秉承"为天下储人才,为国家图富强"的办学宗旨,践行"学无止境,气有浩然"的校训,踔厉奋发,薪火相传,形成了"崇实求新"的校风.同时,坚持"为国育贤",培养各类人才逾60万,造就大批学术名家、兴业英才、治国栋梁,"扎实、朴实、踏实"的独特品格赢得广泛赞誉.

Reinforcement of the two-stage leaching of laterite ores using surfactants

A two-stage leaching process,namely,highpressure acid leaching-atmospheric acid leaching,was used to treat laterite ores under mild conditions.The leaching ratio of Ni was low because of adsorption and incomplete leaching.In this work,surfactants were used as additives to boost the leaching ratio of Ni.The effect of surfactant type(cationic,anionic,and nonionic surfactants)on the leaching ratio of Ni was investigated.Leaching results showed that stearyl trimethyl ammonium chloride(STAC)apparently increased the leaching ratios of valuable metals.The variation in the physicochemical properties of the lixiviant and the residue improved the leaching ratio of Ni in the presence of STAC.Kinetics analysis indicated that the leaching process was controlled by chemical reaction.

Effect of time-odd fields on odd-even mass differences of semi-magic nuclei

The effect of time-odd fields of Skyrme interaction on neutron odd-even mass differences is studied in the framework of axially deformed Skyrme Hartree-Fock(DSHF)+BCS model. To this end, we take into account both the time-even and time-odd fields to calculate the one-neutron and two-neutron separation energies and pairing gaps of semi-magic Ca, Ni, and Sn isotopic chains. In the calculations, a surface-type pairing interaction(IS pairing) and an isospin dependent contact pairing interaction(IS+IV pairing)are adopted on top of Skyrme interactions SLy4, SLy6 and Sk M*, respectively. We find that the time-odd fields have in general small effects on pairing gaps, but achieve better agreement with experimental data using SLy4 and Sly6 interactions, respectively.It is also shown that the calculations with IS+IV pairing reproduce the one-neutron separation energies of Sn isotopes better than those with the IS pairing interaction when the contributions of the time-odd fields are included.

Automated and remote synthesis of poly(ethylene glycol)-mineralized ZIF-8 composite particles via a synthesizer assisted by femtosecond laser micromachining

Mineralization of the ZIF-8 in the presence of biomacromolecules has been demonstrated to be a general way for making bioentities@ZIFs composites.The ZIF-8 crystals permit controlled storage and utilization of the bioentities,thus can benefit drug delivery,cold-chain breaking etc.With the increasing needs on personal care and distributed manufacturing,automated synthesis controlled by a computer becomes the next challenge.In this work,we designed an automatic synthesis system to prepare PEG mineralized ZIF-8 composite particles.This system is based on flow chemistry with the microfluidic chips fabricated by femtosecond laser micromachining.The particles were synthesized and monitored automatically.Furthermore,this synthesizer could be extended for fabrication of vaccine particles under remote control through internet.

Tunable morphologies of polymer capsules templated from cuprous oxide particles for control over cell association

Over the past two decades,layer-by-layer(LbL) assembly of micro/nanocapsules has been of interest for the investigation of bio-nano interactions to explore bio-applications,such as drug delivery.The choice of an appropriate template that can be easily dissolved under mild conditions is one of the challenges for the assembly of LbL capsules.Herein,we report the engineering of LbL capsules with tunable morphologies using cuprous oxide(Cu_2O) particles as templates.Cu_2O particles with cubic,tetradecahedral or spherical morphologies were synthesized via hydrothermal processes,which can be dissolved under mild condition(e.g.,sodium thiosulfate solution).The influence of capsule morphologies on cell association was investigated,which indicates that LbL capsules with cubic geometry promoted cell association up to 4 and 9-fold than tetradecahedral and spherical capsules,respectively.The reported method provides a new avenue for the assembly of LbL capsules with different morphologies,which has the potential for better understanding of biological interactions of LbL capsules.

Co-delivery of enzymes and photosensitizers via metal-phenolic network capsules for enhanced photodynamic therapy

The intrinsic hypoxic tumor microenvironment and limited accumulation of photosensitizers(PSs) result in unsatisfied efficiency of photodynamic therapy(PDT).To enhance the PDT efficiency against solid tumors,a functional oxygen self-supplying and PS-delivering nanosystem is fabricated via the combination of catalase(CAT),chlorin e6(Ce6) and metal-phenolic network(MPN) capsule.It is demonstrated that the CAT encapsulated in the capsules(named CCM capsules) could catalyze the degradation of hydrogen peroxide(H;O;) to produce molecular oxygen(O;),which could be converted into cytotoxicity reactive oxygen species(ROS) by surface-loaded Ce6 under 660 nm laser irradiation,leading to synergistic anticancer effects in vitro and in vivo.Therefore,the application of CCM capsule could be a promising strategy to improve PDT effectiveness.

Co-delivery of anticancer drugs and cell penetrating peptides for improved cancer therapy

Delivery systems based on nanoparticles(NPs)have shown great potential to reduce side effects and improve the therapeutic efficacy.Herein,we report the one-pot synthesis of poly(ethylene glycol)-mediated zeolitic imidazolate framework-8(ZIF-8)NPs for the co-delivery of an anticancer drug(i.e.,doxorubicin)and a cell penetrating peptide containing histidine and arginine(i.e.,H4 R4)to improve the efficacy of therapeutic delive ry.The cargo-encapsulated ZIF-8 NPs are pH-responsive,which are stable at neutral pH and degradable at acidic pH to release the encapsulated cargos.The released H4 R4 can help for endosome/lysosome escape to enhance the cytotoxicity of the encapsulated drugs.In vivo studies demonstrate that the co-delivery of doxo rubicin and H4 R4 peptides can efficiently inhibit tumor growth without significant side effects.The reported strategy provides a new perspective on the design of drug delivery systems and brings more opportunities for biomedical applications.

Water-in-Water Emulsions,Ultralow Interfacial Tension,and Biolubrication

A water-in-water(W/W)emulsion consists of droplets formed by the spontaneous liquid-liquid separation of two immiscible aqueous phases.The inherent properties of the W/W interfaces,low or ultralowinterfacial tension(γ_(W/W)=1-1000μN/m)and a large thickness of several nanometers,beget the poor inherent stability of emulsions.Herein,we report a nanofibril emulsifier having Schiff base reactivity to generate a W/W emulsion.The W/W emulsion has superior stability(stable>6 months)because collagen nanofibrils,acting as a stabilizer of W/W emulsions,can simultaneously satisfy the requirements of sizeandoverall coverage ratio of the phase interfaces.W/Wemulsions having γ_(W/W)∼10μN/m were used as synthetic synovial fluids,showing superior lubrication performance with a coefficient of friction in the range of 0.003-0.011,which has been demonstrated to be suitable for joint lubrication.An intraarticular injection assessment further confirmed this protective effect on articular cartilage in vivo.Our study reveals the mechanism of emulsion stabilization and opens up the possibility of osteoarthritis(OA)treatment using the biolubrication effects of W/W emulsions for lubricated artificial implant surfaces.