碳点增敏的流动注射化学发光法测定食品中二氧化硫的含量

二氧化硫的检测对于食品安全保障具有重要意义。采用酸性高锰酸钾-亚硫酸盐化学发光体系,以碳点(Carbon Dots,CDs)为增敏剂,结合流动注射技术(Flow Injection Analysis,FIA)建立了一种用于检测食品中二氧化硫含量的简便方法。在优化的实验条件下,该方法的线性范围为1.0×10^(-5)–3.0×10^(-4) mol·L^(-1),检出限为7.79×10^(-6) mol·L^(-1)。该实验适合作为本科生仪器分析课程的教学实验,帮助学生掌握化学发光、流动注射分析技术的原理及应用,学习科学研究的基本方法,提高思考能力。

血小板淋巴细胞比值作为非小细胞肺癌预后因素的meta分析

背景与目的目前研究显示,血小板淋巴细胞比值(platelet lymphocyte ratio, PLR)在肾细胞癌、食管癌、胃癌、肝癌以及结肠癌中均有重要的预后价值。本研究旨在通过meta分析,评估PLR对非小细胞肺癌(nonsmall cell lung cancer, NSCLC)患者的预后价值。方法使用计算机电子系统对PubMed、EMBASE、Web of Science、Medline、Cochrane Library、中国知网、中国生物医学文献数据库、维普、万方数据库进行系统文献检索,查阅研究PLR与总生存期(overall survival, OS)和无病生存期(disease-free survival, DFS)之间关联的文献。提取每个符合条件的研究数据,使用风险比率(hazard risk, HR)和95%置信区间(95%confidence interval, 95%CI)进行系统评价分析以评估PLR的预后价值,检索时限为建库至2018年11月。结果我们共纳入15篇研究文献涉及5524名患者进行系统评价分析。Meta分析结果显示:较高PLR组的OS明显低于较低PLR组的OS(HR=1.69, 95%CI:1.45-1.97, P<0.000,01, I^2=46.2%,P异质性=0.026);较高PLR组的DFS明显低于较低PLR组的DFS(HR=1.41, 95%CI:1.14-1.74, P=0.001, I^2=46.2%, P异质性=0.026)。亚组分析显示,按种族、样本大小、PLR临界值和治疗方法分组后,PLR较高组的OS仍明显低于PLR较低组(P<0.05)。结论 PLR增高与NSCLC患者预后不良有关,因此PLR可能作为NSCLC患者重要的生物预测标记,但其临床应用仍需要未来通过更多的研究来验证。

Growth of aligned SnS nanowire arrays for near infrared photodetectors

Aligned SnS nanowires arrays were grown via a simple chemical vapor deposition method.As-synthesized SnS nanowires are single crystals grown along the[111]direction.The single SnS nanowire based device showed excellent response to near infrared lights with good responsivity of 267.9 A/W,high external quantum efficiency of 3.12×10^4%and fast response time.Photodetectors were built on the aligned SnS nanowire arrays,exhibiting a light on/off ratio of 3.6,and the response and decay time of 4.5 and 0.7 s,respectively,to 1064 nm light illumination.

A Novel Millimeter-Wave Channel Measurement Platform for 6G Intelligent Railway Scenarios

This paper presented a novel millimeterwave channel measurement platform for the 6G intelligent railway.This platform used phased array antenna with 64 elements and can support instant bandwidth up to 1 GHz.Combined with improved multi-tone sounding signals,the platform can enhance dynamic measurement capability in high-speed railway scenarios.We performed calibration works about frequency flatness,frequency offset and proved platform reliability with channel emulator based closed-loop verification.We also carried out field trials in high-speed railway carriage scenarios.Based on measurement results,we extracted channel characteristic parameters of path loss,power delay profile and delay spread to further verify the field measurement performance of the platform.

STOCHASTIC ELASTO-PLASTIC FRACTURE ANALYSIS OF ALUMINUM FOAMS

Model I quasi-static nonlinear fracture of aluminum foams is analyzed by considering the effect of microscopic heterogeneity. Firstly, a continuum constitutive model is adopted to account for the plastic compressibility of the metallic foams. The yield strain modeled by a two- parameter Weibull-type function is adopted in the constitutive model. Then, a modified cohesive zone model is established to characterize the fracture behavior of aluminum foams with a cohesive zone ahead of the initial crack. The tensile traction versus local crack opening displacement relation is employed to describe the softening characteristics of the material. And a Weibull statistical model for peak bridging stress within the fracture process zone is used for considering microscopic heterogeneity of aluminum foams. Lastly, the influence of stochastic parameters on the curve of stress-strain is given. Numerical examples are given to illustrate the numerical model presented in this paper and the effects of Weibull parameters and material properties on J-integral are discussed.

Dynamic fracture analysis of adhesive bonded material under normal loading

Dynamic fracture behavior of a Griffith crack along the interface of an adhesive bonded material under normal loading is studied. The singular integral equations are obtained by employing integral transformation and introducing dislocation density functions. By adopting Gauss-Jacobi integration formula, the problem is reduced to the solution of algebraic equations, and by collocation dots method. their solutions can be obtained Based on the parametric discussions presented in the paper, the following conclusions can be drawn： （1） Mode I dynamic stress intensity factor （DSIF） increases with increasing initial crack length and decreasing visco-elastic layer thickness, revealing distinct size effect; （2） The influence of the visco-elastic adhesive relaxation time on the DSIF should not be ignored.

Variation in Bombyx mori immune response against fungal pathogen Beauveria bassiana with variability in cell wallβ-1,3-glucan

Entomopathogenic fungi are protected by a cell wall with dynamic structure for adapting to various environmental conditions.β-1,3-Glucan recognition proteins activate the innate immune system of insects by recognizing surface molecules of fungi.However,the associations between pathogenicity and the different components of entomopathogenic fungal cell walls remain unclear.Three Beauveria bassiana strains were selected that have significantly differing virulence against Bombyx mori.The molecular mechanisms underlying the immune response in B.mori were investigated using RNA sequencing,which revealed differences in the immune response to different B.bassiana strains at 12 h post-infection.Immunofluorescence assays revealed thatβ-1,3-glucan content had an opposite trend to that of fungal virulence.β-1,3-Glucan injection upregulated BmβGRP4 expression and significantly reduced the virulence of the high-virulence strain but not that of the medium-virulence or low-virulence strains.BmβGRP4 silencing in B.mori with RNA interference resulted in the opposite virulence pattern,indicating that the virulence of B.bassiana was affected by the cell walls’content ofβ-1,3-glucan,which could be recognized by BmβGRP4.Furthermore,interference with the gene CnA(calcineurin catalytic A subunit)involved inβ-1,3-glucan synthesis eliminated differences in virulence between B.bassiana strains.These results indicate that strains of a single species of pathogenic fungi that have differing cell wall components are recognized differently by the innate immune system of B.mori.

Antisymmetric planar Hall effect in rutile oxide films induced by the Lorentz force

The conventional Hall effect is linearly proportional to the field component or magnetization component perpendicular to a film. Despite the increasing theoretical proposals on the Hall effect to the in-plane field or magnetization in various special systems induced by the Berry curvature, such an unconventional Hall effect has only been experimentally reported in Weyl semimetals and in a heterodimensional superlattice. Here, we report an unambiguous experimental observation of the antisymmetric planar Hall effect(APHE) with respect to the in-plane magnetic field in centrosymmetric rutile RuO_(2) and IrO_(2) single-crystal films. The measured Hall resistivity is found to be linearly proportional to the component of the applied in-plane magnetic field along a particular crystal axis and to be independent of the current direction or temperature. Both the experimental observations and theoretical calculations confirm that the APHE in rutile oxide films is induced by the Lorentz force. Our findings can be generalized to ferromagnetic materials for the discovery of anomalous Hall effects and quantum anomalous Hall effects induced by in-plane magnetization. In addition to significantly expanding knowledge of the Hall effect, this work opens the door to explore new members in the Hall effect family.

“Three birds with one stone”nanoplatform:Efficient near-infrared-triggered type-I AIE photosensitizer for mitochondria-targeted photodynamic therapy against hypoxic tumors

Currently three major problems seriously limit the practical application of can-cer photodynamic therapy(PDT):(i)the hypoxic tumor microenvironment(TME);(ii)low generation efficiency of toxic reactive oxygen species(ROS)in aggre-gates and(iii)shallow tissue penetration depth of excitation light.Very limited approaches are available for addressing all the above three problems with a single design.Herein,a rational“three birds with one stone”molecular and nanoengi-neering strategy is demonstrated:a photodynamic nanoplatform U-Ir@PAA-ABS based on the covalent combination of lanthanide-doped upconversion nanoparti-cles(UCNPs)and an AIE-active dinuclear Ir(III)complex provides a low oxygen concentration-dependent type-I photochemical process upon 980 nm irradiation by Föster resonance energy transfer(FRET).U-Ir@PAA-ABS targets mitochondria and has excellent phototoxicity even in severe hypoxia environments upon 980 nm irradiation,inducing a dual-mode cell death mechanism by apoptosis and ferropto-sis.Taken together,the in vitro and in vivo results demonstrate a successful strategy for improving the efficacy of PDT against hypoxic tumors.

Polarization-entangled photon pairs with factorable spectra engineered by using an uneven four-stage nonlinear interferometer

We report the generation of polarization-entangled photon pairs in the 1550 nm band by pumping an uneven nonlinear interferometer loop with two orthogonally polarized counterpropagating pump pulses.The uneven nonlinear interferometer,providing a more ideal interference pattern due to the elimination of secondary maxima,consists of four pieces of dispersion-shifted fibers sandwiched with three pieces of standard single-mode fibers,and the lengths of the nonlinear fibers follow the binomial distribution.The mode number of the photon pairs deduced from the measured joint spectrum is∼1.03.The collection efficiency of the photon pairs is found to be∼94%(after background noise correction).The directly measured visibility of two-photon interference of the polarization-entangled photon pairs is∼92%,while no interference is observed in the direct detection of either the signal or idler photons.

YAP Inactivation by Soft Mechanotransduction Relieves MAFG for Tumor Cell Dedifferentiation

Solid tumor cells live in a highly dynamic mechanical microenvironment.How the extracellular-matrix-generated mechanotransduction regulates tumor cell development and differentiation remains an enigma.Here,we show that a low mechanical force generated from the soft matrix induces dedifferentiation of moderately stiff tumor cells to soft stem-cell-like cells.Mechanistically,integrin?was identified to transduce mechano-signaling to trigger tumor cell dedifferentiation by recruiting RhoGDI1 to inactivate RhoA and subsequently Yes-associated protein(YAP).YAP inactivation relieved the inhibition of v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog G(MAFG),allowing MAFG to transactivate the stemness genes NANOG,SOX2,and NESTIN.Inactivation also restoredβ8 expression,thereby forming a closed mechanical loop.Importantly,MAFG expression is correlated with worse prognosis.Our findings provide mechanical insights into the regulation of tumor cell dedifferentiation,which has therapeutic implications for exploring innovative strategies to attack malignancies.

Two cases on primary bone marrow lymphoma

Managing Editor:Peng Lyu Primary bone marrow lymphoma(PBML)is a rare lymphoma accounting for 1.23%of non-Hodgkin lymphoma(NHL)cases.It is characterized by tumor cells invading only the bone marrow without systemic lymphadenopathy or extranodal organ involvement.Owing to the lack of standardized treatment regimens,most patients are treated using rituximab with cyclophosphamide,doxorubicin,vincristine,and prednisone(R-CHOP)regimens;however,their efficacy needs to be further investigated.

Stretchable SnO2-CdS interlaced-nanowire film ultraviolet photodetectors

Stretchable ultraviolet photodetectors with fast response have wide applications in wearable electronics and implantable biomedical devices. However, most of the conventional binary oxide nanowires based photodetectors exhibit slow response due to the presence of a large number of surface defects related to trapping centers. Herein, with interlaced SnO2-CdS nanowire films as the sensing materials, we fabricated stretchable ultraviolet photodetectors with significantly improved response speed via a multiple lithographic filtration method. Systematic investigations reveal that the interlaced-nanowire based photodetectors have lower dark current and much higher response speed(more than 100 times) compared with pure SnO2 nanowire based photodetectors. The relevant carrier generation and transport mechanism were also discussed. In addition, due to the formation of waved wrinkles on the surface of the nanowires/PDMS layer during the prestretching cycles, the SnO2-CdS interlaced nanowire photodetectors display excellent electrical stability and stretching cyclability within 50% strain, without obvious performance degradation even after 150 stretching cycles. As a simple and effective strategy to fabricate stretchable ultraviolet photodetectors with high response speed, the interlacednanowire structure can also be applied to other nanowire pairs, like ZnO-CdS interlaced-nanowires. Our method provides a versatile way to fabricate fast speed ultraviolet photodetectors by using interlaced metal oxide nanowires-CdS nanowires structures, which is potential in future stretchable and wearable optoelectronic devices.

Antidiabetic effects of multi-species probiotic and its fermented milk in mice via restoring gut microbiota and intestinal barrier

Probiotic is a promising nutritional intervention for the prevention and alleviation of type 2 diabetes (T2DM).In this study,the remission potential of a multi-species probiotic (Lactobacillus acidophilus NCFM,Lactobacillus rhamnosus GG,Bifidobacterium lactis HN019 and Streptococcus thermophilus ST447) and its fermented yoghurt on the symptoms of high fat diet and streptozotocin induced T2DM mice were investigated,and the underlying mechanisms were elucidated.Multi-species probiotic and probiotic yoghurt elicited similar but varying efficacy in decreasing the body weight loss,improving organ weight,glucose tolerance and insulin resistance,regulating the levels of blood glucose,HbA1c,insulin and lipid as well as protecting the pancreatic islets.Their tangible antidiabetic effects may be ascribed to the mutual promotion between the repair of the intestinal barrier/permeability and the optimization of gut microbiota structure.Furthermore,the intestinal flora-short chain fatty acids-intestinal hormones/inflammatory pathway was activated and thereby conferring healthy benefits to the host.This proposed probiotic combination appears to provide a viable approach to alleviate T2DM.

An integrated flexible multifunctional sensing system for simultaneous monitoring of environment signals

With the rapid development of portable devices and internet of things,the requirement of system wearability and integration accelerates the investigation of flexible multifunctional sensors.In this study,we developed an integrated flexible sensing system with four nanowire-based sensors and a Ni microwire-based temperature sensor.The four nanowirebased sensors are three kinds of photodetectors responding to lights with different wavelengths and a gas sensor.Due to the large surface volume ratio and considerable sub wavelength effect,all the nanowire-based sensors show good sensing response and excellent linear relationship between sensitivity and temperature.The as-fabricated flexible sensing system can simultaneously detect environmental parameters,including temperature change,light intensities from UV-Visible to near infrared regions,and harmful gas concentration.Our flexible multifunctional sensing system therefore opens up a new way for the emerging portable and wearable electronics.

MA Cation-Induced Diffusional Growth of Low-Bandgap FA-Cs Perovskites Driven by Natural Gradient Annealing

Low-bandgap formamidinium-cesium(FA-Cs)perovskites of FA_(1-x)CsxPbI_(3)(x<0:1)are promising candidates for efficient and robust perovskite solar cells,but their black-phase crystallization is very sensitive to annealing temperature.Unfortunately,the low heat conductivity of the glass substrate builds up a temperature gradient within from bottom to top and makes the initial annealing temperature of the perovskite film lower than the black-phase crystallization point(~150℃).Herein,we take advantage of such temperature gradient for the diffusional growth of high-quality FA-Cs perovskites by introducing a thermally unstable MA^(+)cation,which would firstly formα-phase FA-MA-Cs mixed perovskites with low formation energy at the hot bottom of the perovskite films in the early annealing stage.The natural gradient annealing temperature and the thermally unstable MA^(+)cation then lead to the bottom-to-top diffusional growth of highly orientatedα-phase FA-Cs perovskite,which exhibits 10-fold of enhanced crystallinity and reduced trap density(~3:85×10^(15) cm^(−3)).Eventually,such FA-Cs perovskite films were fabricated into stable solar cell devices with champion efficiency up to 23.11%,among the highest efficiency of MA-free perovskite solar cells.

Flexible ultraviolet photodetectors based on ZnO–SnO_2 heterojunction nanowire arrays

A ZnO–SnO_2 nanowires（NWs） array, as a metal oxide semiconductor, was successfully synthesized by a near-field electrospinning method for the applications as high performance ultraviolet photodetectors. Ultraviolet photodetectors based on a single nanowire exhibited excellent photoresponse properties to 300 nm ultraviolet light illumination including ultrahigh I_（on）/I_（off） ratios（up to 10~3）, good stability and reproducibility because of the separation between photo-generated electron-hole pairs. Moreover, the NWs array shows an enhanced photosensing performance. Flexible photodetectors on the PI substrates with similar tendency properties were also fabricated. In addition, under various bending curvatures and cycles, the as-fabricated flexible photodetectors revealed mechanical flexibility and good stable electrical properties, showing that they have the potential for applications in future flexible photoelectron devices.

Nonrelativistic and nonmagnetic terahertz-wave generation via ultrafast current control in anisotropic conductive heterostructures

Precise and ultrafast control over photo-induced charge currents across nanoscale interfaces could lead to important applications in energy harvesting,ultrafast electronics,and coherent terahertz sources.Recent studies have shown that several relativistic mechanisms,including inverse spin-Hall effect,inverse Rashba–Edelstein effect,and inverse spin-orbit-torque effect,can convert longitudinally injected spinpolarized currents from magnetic materials to transverse charge currents,thereby harnessing these currents for terahertz generation.However,these mechanisms typically require external magnetic fields and exhibit limitations in terms of spin-polarization rates and efficiencies of relativistic spin-to-charge conversion.We present a nonrelativistic and nonmagnetic mechanism that directly utilizes the photoexcited high-density charge currents across the interface.We demonstrate that the electrical anisotropy of conductive oxides RuO2 and IrO2 can effectively deflect injected charge currents to the transverse direction,resulting in efficient and broadband terahertz radiation.Importantly,this mechanism has the potential to offer much higher conversion efficiency compared to previous methods,as conductive materials with large electrical anisotropy are readily available,whereas further increasing the spin-Hall angle of heavy-metal materials would be challenging.Our findings offer exciting possibilities for directly utilizing these photoexcited high-density currents across metallic interfaces for ultrafast electronics and terahertz spectroscopy.

The cytoprotection of milk-derived MFG-E8 on mitochondria-injured L6 cell via mediation of Akt/bcl-2/bax-caspase-3 signaling pathway

Mitochondria-dependent myoblast apoptosis induced by oxidative stress and decrease in successful protein synthesis play a crucial role in loss of muscle mass and functionality further to result in sarcopenia.Here,we investigated the relationship between milk fat globule-EGF factor VIII(MFG-E8)and mitochondrial-dependent apoptosis pathway.MFG-E8 exert cytoprotection through increasing L6 cells survival/apoptotic ratio,increasing mitochondrial membrane potential and regulating S and G2/M phases.By observing cell ultrastructure,MFG-E8 improved mitochondrial homeostasis mainly through decreasing cytochrome-c release,expression of caspase-9 and caspase-3,mitochondrial vacuolation and mitophagy thereby inhibiting cell apoptosis.From molecular perspective,MFG-E8 repaired mitochondria fragmentation by increasing mitochondrial DNA replication and regulated expression of key mitochondrial-apoptotic factors(upregulation:B-cell lymphoma-2 like 1(bcl2l1),bcl2l2,cyclooxygenase-1 and mitochondrial uncoupling protein-2;Downregulation:p21 and p53)further to improve mitochondrial function and inhibit apoptosis.Moreover,MFG-E8 inhibited mitochondrialdependent apoptosis via Akt/bcl-2/bax/caspase-3 signaling cascades.Taken together,our research provided a promising approach for deep exploration of MFG-E8 on cytoprotection against mitochondrial injury and mitochondrial-mediated apoptosis and application of anti-apoptosis in alleviating sarcopenia.

Idiopathic pulmonary fibrosis associated with circulating autoantibodies:a Chinese cohort of a long-term follow-up study

The term of interstitial pneumonia with autoimmune features(IPAF),based on a combination of clinical,serological,and morphological domains(specific chest imaging features,histopathological features,or multi-compartment involvement,including non-specific interstitial pneumonia[NSIP],organizing pneumonia,NSIP with organizing pneumonia overlap and lymphoid interstitial pneumonia).