Local density of optical states calculated by the mode spectrum in stratified media

The local density of optical states(LDOS)is an important physical concept,which can characterize the spontaneous emission of microcavities.In order to calculate the LDOS,the relationship between the mode spectrum and the LDOS is established.Then,based on the transfer matrix method and the effective resonator model,the leaky loss of the leaky mode and the mode spectrum in the one-dimensional photonic bandgap crystal waveguide are calculated,results of which indicate that the mode spectrum can characterize the leaky loss of the leaky mode.At last,the density of optical states(DOS),and the LDOS in each layer are calculated.The partial DOS and the partial LDOS in the quantum well,related to the fundamental leaky mode,can be used to find out the optimal location of the quantum well in the defect layer to couple more useful photons into the lasing mode for lasers.

S1PR1 serves as a viable drug target against pulmonary fibrosis by increasing the integrity of the endothelial barrier of the lung

Idiopathic pulmonary fibrosis(IPF)is a progressive lung disease with unclear etiology and limited treatment options.The median survival time for IPF patients is approximately 2–3 years and there is no effective intervention to treat IPF other than lung transplantation.As important components of lung tissue,endothelial cells(ECs)are associated with pulmonary diseases.However,the role of endothelial dysfunction in pulmonary fibrosis(PF)is incompletely understood.Sphingosine-1-phosphate receptor 1(S1PR1)is a G protein-coupled receptor highly expressed in lung ECs.Its expression is markedly reduced in patients with IPF.Herein,we generated an endothelial-conditional S1pr1 knockout mouse model which exhibited inflammation and fibrosis with or without bleomycin(BLM)challenge.Selective activation of S1PR1 with an S1PR1 agonist,IMMH002,exerted a potent therapeutic effect in mice with bleomycin-induced fibrosis by protecting the integrity of the endothelial barrier.These results suggest that S1PR1 might be a promising drug target for IPF therapy.

ACAT1 deficiency in myeloid cells promotes glioblastoma progression by enhancing the accumulation of myeloid-derived suppressor cells

Glioblastoma(GBM)is a highly aggressive and lethal brain tumor with an immunosuppressive tumor microenvironment(TME).In this environment,myeloid cells,such as myeloid-derived suppressor cells(MDSCs),play a pivotal role in suppressing antitumor immunity.Lipometabolism is closely related to the function of myeloid cells.Here,our study reports that acetyl-CoA acetyltransferase 1(ACAT1),the key enzyme of fatty acid oxidation(FAO)and ketogenesis,is significantly downregulated in the MDSCs infiltrated in GBM patients.To investigate the effects of ACAT1 on myeloid cells,we generated mice with myeloid-specific(LyzM-cre)depletion of ACAT1.The results show that these mice exhibited a remarkable accumulation of MDSCs and increased tumor progression both ectopically and orthotopically.The mechanism behind this effect is elevated secretion of C-X-C motif ligand 1(CXCLI)of macrophages(Mo).Overall,our findings demonstrate that ACAT1 could serve as a promising drug target for GBM by regulating the function of MDSCs in the TME.

Improvement on the topological localized interface enabled by chiral symmetry

Zero-energy topological states,which are protected by chiral symmetry against certain perturbations topologically,localize at interfaces between trivial and non-trivial phases in the Su–Schrieffer–Heeger(SSH)chain model.Here,we propose and demonstrate a method to manipulate chiral symmetry itself to improve the localized interfaces and enlarge the mode volume of topological states in the SSH model,thus optimizing the lasing performance of localized interfaces.As multiple defects corresponding to off-diagonal perturbations in an eigenmatrix are introduced,the topological state expands and extends to extra defects at the topological interface without breaking chiral symmetry.We apply the proposed method in electrical pumping semiconductor laser arrays to verify our theoretical prediction and optimize the output characteristics of the devices.The measured results of the proposed multi-defect SSH laser array show that the output power has been increased by 27%,and the series resistance and far-field divergence have been reduced by half compared to the traditional SSH laser array,establishing a high-performance light source for integrated silicon photonics,infrared light detection and ranging,and so on.Our work demonstrates that the proposed method is capable of improving topological localized interfaces and redistributing zero-energy topological states.Furthermore,our method can be applied to other platforms and inspire optimizations of more devices in broader areas.

A novel S1P1 modulator IMMH002 ameliorates psoriasis in multiple animal models

Psoriasis is characterized by abnormal proliferation of keratinocytes,as well as infiltration of immune cells into the dermis and epidermis,causing itchy,scaly and erythematous plaques of skin.The understanding of this chronic inflammatory skin disease remains unclear and all available treatments have their limitations currently.Here,we showed that IMMH002,a novel orally active S1 P1 modulator,desensitized peripheral pathogenic lymphocytes to egress signal from secondary lymphoid organs and thymus.Using different psoriasis animal models,we demonstrated that IMMH002 could significantly relieve skin damage as revealed by PAS I score and pathological injure evaluation.Mechanistically,IMMH002 regulated CD3+T lymphocytes re-distribution by inducing lymphocytes’homing,thus decreased T lymphocytes allocation in the peripheral blood and skin but increased in the thymus.Our results suggest that the novel SIP1 agonist,IMMH002,exert extraordinary capacity to rapidly modulate T lymphocytes distribution,representing a promising drug candidate for psoriasis treatment.

电注入下的人工微结构模式调控激光研究进展

电注入半导体激光器相较于其他类型激光器具有电光转换效率高、体积小、寿命长等优势,近年来在显示、材料加工、医疗、通讯等领域的市场占有份额日益增长.激光器的模式特性直接影响激光器的输出性能,如功率、光束质量、光谱线宽等通过引入人工微结构,结合宇称时间对称、连续谱束缚态以及多模腔杂化调控手段,不仅可以拓展半导体激光器的物理研究范畴,同时有效优化激光器的性能,进一步增加了半导体激光器的多元应用场景.本文从模式调控的角度出发,对电注入下的人工微结构半导体激光器展开综述,包括国内外研究发展现状、物理原理以及相应的应用,最后进行了总结与展望.

Using X-ray computed tomography and micro-Raman spectrometry to measure individual particle surface area, volume, and morphology towards investigating atmospheric heterogeneous reactions

Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography（XCT） and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional（3-D） rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy（FE-SEM） to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.

Copper（I）-Catalyzed Trifluoromethylation of Phthalic Anhydride Derivatives with （Trifluoromethyl）trimethylsilane

使用的代替的酞酸酐(trifluoromethyl ) 的有效催化铜的 trifluoromethylation trimethylsilane (Me3SiCF3 ) 作为亲核的 trifluoromethylating 试剂面对 1,10-phenanthroline 和 KF，由与水熄灭反应混合列在后面被开发了。可能的机制被建议。

High peak power density and low mechanical stress photonic-band-crystal diode laser array based on non-soldered packaging technology

A high peak power density and low mechanical stress photonic-band-crystal(PBC)diode laser array based on non-soldered packaging technology is demonstrated.The array consists of the PBC diode laser bars with small fast axis divergence angles.Meanwhile,we design the non-soldered array structure that realizes mechanical stacking of 10 bars in the vertical direction.In the experiment,the peak power density of the PBC array is about 1.75 times that of the conventional array when the same total power is obtained.The peak power of the non-soldered array is 292.2 W,and the“smile”effect is improved by adjusting the mechanical fixing force of the array.