Metal-based inorganic nanocrystals for biological sonodynamic therapy applications:recent progress and perspectives

With the fast development of technology for the treatment of tumor and bacteria,photo-therapeutic strate-gies emerge as a kind of highly effective and common treatment,but the low tissue penetration depth of light limits their development.Sonodynamic therapy(SDT),as an efficient and non-invasive treatment,attracts more people's attention due to the inherent property of high tissue penetration.The soft tissue penetration depth of ultrasound(US)can even reach more than 10 cm,which has great advantage over that of light.Therefore,many sonosensitizers are studied and applied to SDT-based therapy.Metal-based inorganic nanocrystals are able to generate more reactive oxygen species(ROS)due to the special composition and band structure.The representative achievements and the specific functions of the nanocrystals sonosensitizers are summarized in this work,and the relationship of structure/composition-SDT performance and the internally regulated composite is revealed.Syner-gistic effects of SDT in combination with other therapeutic modalities are mainly highlighted.At the same time,the critical and potential issues and future perspectives are addressed.

Austenite Grain Refinement by Reverse α′→γ Transformation in Metastable Austenitic Manganese Steel

Microstructure of metastable austenitic manganese steel after reverse transformation treatment was investi gated using optical microscopy, X ray diffraction （XRD）, electrical resistivity and hardness testing. Austenite grain refinement was successfully achieved by a two-step heat treatment. First, martensite was produced by cooling the so- lution-treated samples to --196 ℃. Then, the deep cryogenic treated samples were heated to 850 ℃ upon slow or rapid heating. The mean size of original austenite grain was about 400 fire. But the mean size of equiaxed reversion austenite was refined to 50 μm. Microstructure evolution and electrical resistivity change showed that martensite plates underwent tempering action upon slow heating, and the residual austenite was decomposed, resulting in the formation of pearlite nodules at the austenite grains boundaries. The refinement mechanism upon slow heating is the diffusion-controlled nucleation and growth of austenite. However, the reverse transformation upon rapid heating was predominated by displacive manner. The residual austenite was not decomposed. The plate α-phase was carbon-super- saturated until the starting of reverse transformation. The reverse transformation was accompanied by surface effect, resulting in the formation of plate austenite with high density dislocations. The refinement mechanism upon rapid heating is the recrystallization of displacive reversed austenite.

Microstructure Refinement and Property Improvement of Metastable Austenitic Manganese Steel Induced by Electropulsing

Grain refinement efficiency of electropulsing treatment （EPT） for metastable austenitic manganese steel was investigated. The mean grain size of original austenite is 300 ptm. However, after EPT, the microstructure ex hibits a bimodal grain size distribution, and nearly 70vol. % grains are less than 60 /Lm. The refined austenite results in ultrafine martensitic microstrncture. The tensile strengths of refined austenitic and martensitic microstructures were improved from 495 to 670, and 794 to 900 MPa respectively. The fine grained materials possess better fracture toughness. The work hardening capacity and wear resistance of the refined austenitic microstructure are improved. The reasonable mechanism of grain refinement is the combination of accelerating new phase nucleation and restraining the growth of neonatal austenitic grain during reverse transformation and rapid recrystallization induced by electropulsing.

Telluride semiconductor nanocrystals:progress on their liquid-phase synthesis and applications

The synthesis of colloidal telluride semiconductor nanocrystals(CT-SNCs)is more challenging than that of chalcogenides,due to the smaller electron affinity of tellurium than that of sulfur and selenium,which is attributed to its metalloid property.While some new potential strategies were developing with the increasing demand of CT-SNCs,the cation exchange reaction(CER)has particularly become a new strategy to synthesize highquality CT-SNCs and their corresponded hetero-nanostructures.This review summarizes the synthesis strategies of CT-SNCs,including traditional methods and new methods with emphasis on CERs,and their resulting CTSNCs with well-controlling size,shape,composition,crystallization and hetero-interfaces cooperatively.The progressive synthesis methods give rise to the excellent optical properties of CT-SNCs.This review also covers the recent progress of their applications in the field of photoelectric detection,catalysis,batteries and biology.The new hybrid CT-SNCs nanostructures are also emphasized and systematically discussed due to their enhanced properties.

Editorial for rare metals, special issue on nanomaterials and rechargeable battery applications

Energy and environmental problems have raised great concerns in recent years.Increasing demand and consumption on energy cause many environmental problems.Therefore,the significance of renewable energy is increasing steadily.

Neoadjuvant immune checkpoint inhibitor plus chemotherapy in rare tracheal tumors

Dear Editor,Primary malignant tumors of the trachea account for 0.01%-0.4%of all cancer cases[1].Due to their locally aggressive growth,surgical resection including carinal resection and airway reconstruction was most frequently applied for these diseases[2].However,tracheal surgery is technically challenging and is associated with high rates of operative morbidity and mortality.Effective neoadjuvant treatment is expected to reduce the tumor load and lessen the extent of resecting primary tracheal tumors.However,evidence regarding neoadjuvant treatment for tracheal tumors remains relatively scarce and platinumbased doublet chemotherapy remains the standard in this setting.Immune checkpoint inhibitors are a promising approach to neoadjuvant treatment.