Measuring small longitudinal phase shifts via weak measurement amplification

Weak measurement amplification,which is considered as a very promising scheme in precision measurement,has been applied to various small physical quantities estimations.Since many physical quantities can be converted into phase signals,it is interesting and important to consider measuring small longitudinal phase shifts by using weak measurement.Here,we propose and experimentally demonstrate a novel weak measurement amplification-based small longitudinal phase estimation,which is suitable for polarization interferometry.We realize one order of magnitude amplification measurement of a small phase signal directly introduced by a liquid crystal variable retarder and show that it is robust to the imperfection of interference.Besides,we analyze the effect of magnification error which is never considered in the previous works,and find the constraint on the magnification.Our results may find important applications in high-precision measurements,e.g.,gravitational wave detection.

A Scd1-mediated metabolic alteration participates in liver responses to low-dose bavachin

Hepatotoxicity induced by bioactive constituents in traditional Chinese medicines or herbs,such as bavachin(BV)in Fructus Psoraleae,has a prolonged latency to overt drug-induced liver injury in the clinic.Several studies have described BV-induced liver damage and underlying toxicity mechanisms,but little attention has been paid to the deciphering of organisms or cellular responses to BV at no-observed-adverse-effect level,and the underlying molecular mechanisms and specific indicators are also lacking during the asymptomatic phase,making it much harder for early recognition of hepatotoxicity.Here,we treated mice with BV for 7 days and did not detect any abnormalities in biochemical tests,but found subtle steatosis in BV-treated hepatocytes.We then profiled the gene expression of hepatocytes and non-parenchymal cells at single-cell resolution and discovered three types of hepatocyte subsets in the BV-treated liver.Among these,the hepa3 subtype suffered from a vast alteration in lipid metabolism,which was characterized by enhanced expression of apolipoproteins,carboxylesterases,and stearoyl-CoA desaturase 1(Scd1).In particular,increased Scd1 promoted monounsaturated fatty acids(MUFAs)synthesis and was considered to be related to BV-induced steatosis and polyunsaturated fatty acids(PUFAs)generation,which participates in the initiation of ferroptosis.Additionally,we demonstrated that multiple intrinsic transcription factors,including Srebf1 and Hnf4a,and extrinsic signals from niche cells may regulate the above-mentioned molecular events in BV-treated hepatocytes.Collectively,our study deciphered the features of hepatocytes in response to BV insult,decoded the underlying molecular mechanisms,and suggested that Scd1 could be a hub molecule for the prediction of hepatotoxicity at an early stage.

Emergence of High-Temperature Superconducting Phase in Pressurized La_(3)Ni_(2)O_(7)Crystals

The recent report of pressure-induced structural transition and signature of superconductivity with T_(c)≈80 K above 14 GPa in La_(3)Ni_(2)O_(7)crystals has garnered considerable attention.To further elaborate this discovery,we carried out comprehensive resistance measurements on La_(3)Ni_(2)O_(7)crystals grown in an optical-image floating zone furnace under oxygen pressure(15 bar)using a diamond anvil cell(DAC)and cubic anvil cell(CAC),which employ a solid(KBr)and liquid(glycerol)pressure-transmitting medium,respectively.Sample 1 measured in the DAC exhibits a semiconducting-like behavior with large resistance at low pressures and gradually becomes metallic upon compression.At pressures P 13.7 GPa we observed the appearance of a resistance drop of as much as~50%around 70 K,which evolves into a kink-like anomaly at pressures above 40 GPa and shifts to lower temperatures gradually with increasing magnetic field.These observations are consistent with the recent report mentioned above.On the other hand,sample 2 measured in the CAC retains metallic behavior in the investigated pressure range up to 15 GPa.The hump-like anomaly in resistance around~130 K at ambient pressure disappears at P≥2 GPa.In the pressure range of 11–15 GPa we observed the gradual development of a shoulder-like anomaly in resistance at low temperatures,which evolves into a pronounced drop of resistance of 98%below 62 K at 15 GPa,reaching a temperature-independent resistance of 20μΩbelow 20 K.Similarly,this resistance anomaly can be progressively shifted to lower temperatures by applying external magnetic fields,resembling a typical superconducting transition.Measurements on sample 3 in the CAC reproduce the resistance drop at pressures above 10 GPa and realize zero resistance below 10 K at 15 GPa even though an unusual semiconducting-like behavior is retained in the normal state.Based on these results,we constructed a dome-shaped superconducting phase diagram and discuss some issues regarding the sample-dependent behaviors on pressure-induced hightemperature superconductivity in the La_(3)Ni_(2)O_(7)crystals.

智能脉冲技术辅助TPRK术的临床疗效

目的:观察智能脉冲技术(SPT)辅助的经上皮准分子激光角膜切削术(TPRK)的临床效果。方法:回顾性非随机性研究。选取2017-08/2018-05在我院接受SPT辅助的TPRK手术的近视患者260例508眼,术后随访3mo,检测患者的裸眼视力(UCVA)和等效球镜度,观察角膜上皮愈合情况,评估患者的疼痛度及满意度情况。结果:本组患者术后5d内在配戴角膜绷带镜的状态下可以进行日常生活及一般工作,术后1、3moUCVA(-0.080±0.0798、-0.108±0.089)均达到甚至优于术前BCVA(-0.050±0.0561)。术后5d,所有患者的角膜上皮均完全修复,术后1、3mo随访,仅3例4眼患者在裂隙灯显微镜下观察到不影响视力的haze(0~1级)。本组患者208例术后当天感觉疼痛,均于1d后缓解,3d后完全消失。术后3mo进行满意度调查显示93.0%患者非常满意。结论:SPT辅助的TPRK术治疗近视临床效果较好,术后视力恢复快,角膜上皮重塑时间短,能很好地缓解表层手术后疼痛,患者满意度较高。

Two New Quinazoline Derivatives from the Moss Endophytic Fungus Aspergillus sp. and Their Anti-inflammatory Activity

Two new quinazoline derivatives versicomides E(1)and F(2),and 10 known compounds(3-12)were isolated from the moss endophytic fungus Aspergillus sp.Their structures were determined on the basis of extensive spectroscopic data analysis and ECD calculations.Among them,the compound 7(6-hydroxy-3-methoxyviridicatin)was first reported as a natural product.Inhibition on LPS-induced NO production in RAW 264.7 murine macrophages found that compounds 5,7 and 8 showed significant inhibitory effects on NO production,with IC50 values of 49.85,22.14 and 46.02μM respectively.

Electrochemical Selective Oxidative Synthesis of Diversified Sulfur Heterocycles fromβ-Ketothioamides

Main observation and conclusion A general and practical protocol for the construction of diversified sulfur heterocycles has been described through organic electrosynthesis means.In undivided cell,dihydrothiophenes,thiazolines and 1,4-dithiines could be easily generated from various availableβ-ketothioamides under metal-free and external oxidant-free conditions.

Cloning and Preliminary Characterization of Three Receptor-like Kinase Genes in Soybean

Leaf senescence that occurs in the last stage of leaf development is a genetically programmed process. It is very significant to isolate the upstream components in the senescence signaling pathway and to elucidate the molecular mechanisms that control the initiation and progression of leaf senescence. In this study, full-length cDNAs of three receptor-like protein kinase genes, designated rlpkl, rlpk2 and rlpk3, were cloned from artificially-induced senescent soybean （Glycine max L.） primary leaves （GenBank accession AY687390, AY687391, AF338813）. The deduced amino acid sequences indicated that they belonged to a receptor-like kinase family. Each of rlpkl and rlpk2 encodes a leucine-rich repeat （LRR） receptor-like protein kinase. They both comprise a typical signal peptide, several LRR motifs, a single-pass transmembrane domain, and a cytoplasmic protein kinase domain. No typical extracellular domain of RLPK3 was predicted. Organ-specific expression pattern analysis by reverse-transcription polymerase chain reaction （RT-PCR） revealed higher expression levels of the three genes in cotyledons, roots and flowers. Phylogenetic analysis indicated that RLPK1 and RLPK2 belonged to an independent branch, whereas RLPK3 shared common nodes with several known RLKs responding to ablotic and biotic stresses. The evident alternations of expression profiles of rlpkl and rlpk2 induced by the artificial senescence-inducing treatment implied involvements of these two RLKs in regulating soybean leaf senescence.