慢性阻塞性肺疾病患者血清瘦素水平临床分析

目的了解慢性阻塞性肺疾病（COPD）患者不同时期血清瘦素（1eptin）的水平变化以及其与气道炎症的关系。方法选择我院住院慢性阻塞性肺疾病患者67例，分别测定其急性加重期和临床稳定期血清]eptin、C反应蛋白（CRP）和白蛋白（ALB）水平。结果急性加重期leptin、CRP及ALB水平与临床稳定期比较有统计学意义（P〈0．01）。急性加重期leptin水平与ALB呈负相关；与CRP呈正相关。结论COPD患者急性加重期leptin明显升高，可作为急性加重期的炎性标记物。     

慢性阻塞性肺疾病患者血清基质金属蛋白酶、VEGF水平的变化及其临床意义

目的探讨慢阻肺患者血清基质金属蛋白酶(MMP-9)、VEGF水平的变化及其临床意义。方法选取2014年8月-2016年5月在我院接受治疗的慢阻肺患者为观察对象,根据其疾病分期分为急性加重期组(50例)和稳定期组(45例),同时选取50例在我院参与体检的健康成年人的基本资料作为正常对照组。观察三组血清基质金属蛋白酶、VEGF、炎症细胞因子水平、肺功能和气道阻力的差异,分析慢阻肺患者血清基质金属蛋白酶、VEGF水平与炎症细胞因子、肺功能和气道阻力的相关性。结果急性加重期组和稳定期组患者血清MMP-9、VEGF、IL-6、hs-CRP、TNF-α水平和气道阻力指标Z5、Fres、R5等均高于对照组患者,且急性加重期组患者血清基质金属蛋白酶、VEGF水平与炎症细胞因子和气道阻力指标均高于稳定期组患者,差异有统计学意义(P0.05)。急性加重期组和稳定期组患者肺功能指标FVC、FEV_1及FEV_1/FVC水平均低于对照组患者,且急性加重期组患者肺功能指标均低于稳定期组患者,差异有统计学意义(P0.05)。慢阻肺患者的MMP-9和VEGF水平与患者炎症细胞因子水平和气道阻力正相关,与肺功能指标负相关。结论慢阻肺患者的基质金属蛋白酶、VEGF水平有升高,且与患者的肺功能降低、炎症细胞因子水平和气道阻力上升密切相关。     

慢性阻塞性肺疾病患者免疫球蛋白的表达及与肺功能的关系

目的探讨慢性阻塞性肺疾病(简称慢阻肺)患者免疫球蛋白的表达及与肺功能的关系。方法选取2011年6月至2013年6月在我院门诊随诊的稳定期慢阻肺患者62例作为慢阻肺稳定期组、呼吸内科住院的重症慢阻肺患者58例为慢阻肺急性加重期组(AECOPD)及本院体检中心行健康体检者50例为健康对照组。全部入选者均行肺功能检查并测定免疫球蛋白M(IgM)、免疫球蛋白G(IgG)、免疫球蛋白A(IgA)、C反应蛋白(CRP)和白蛋白(ALB)。结果 3组间IgA、IgG、CRP、ALB检测结果差异有统计学意义(P0.05),慢阻肺急性加重期组和慢阻肺稳定期组中的IgA、IgG、ALB低于健康对照组、CRP高于健康对照组(P0.05);慢阻肺急性加重期组中的ALB低于慢阻肺稳定期组、CRP高于慢阻肺稳定期组(P0.05)。慢阻肺组患者的FEV1和FVC与IgG、IgA和ALB呈显著正相关(P0.05),与CRP呈显著负相关(P0.05)。结论慢阻肺患者存在体液免疫功能障碍,且随着病情的加重和肺功能的降低其免疫功能呈进行性减退。     

慢性阻塞性肺疾病不同病程肺功能动态改变特点和机制的研究

目的　探讨慢性阻塞性肺疾病（COPD）急性加重期和稳定期肺功能的动态改变特点和机制。方法　对30例COPD患者分别于急性加重期和稳定期进行Borg气急指数评估、肺通气功能检测、肺容量检测、体积描记法总气道阻力（Rtot）测定和呼吸阻抗、呼吸阻力检测。结果　Borg气急指数稳定期较急性加重期显著下降（P〈0．001）。通气功能测定参数FVC、FVC／pre、FEVI、FEVI／pre和FEV1／FVC稳定期较急性加重期显著增加（P均〈0．05）。肺容量检测参数深吸气量（IC）稳定期较急性加重期显著增加（P〈0．001），胸腔内气体容积（ITGV）和残气量（RV）稳定期较急性加重期显著下降（P均〈0．05）。Rtot稳定期较急性加重期显著下降（P〈0．01）。IOS测定参数共振频率（Fres）、呼吸总阻抗（Z5）、总气道阻力（R5）、中央气道阻力（R20）和外周气道阻力（R5-R20）稳定期较急性加重期显著下降（P均〈0．05），5Hz时呼吸电抗（X5）稳定期较急性加重期显著增高（P〈0．001）。通气功能检测参数中FEV-改善率最高，肺容量检测IC改善率最高，呼吸阻抗和呼吸阻力检测R5—R20和X5改善率较高。IC、RV和ITGV稳定期较急性加重期的改善值与FVC的改善值显著相关（P均〈0．05），IC和RV稳定期的改善值与FEV-的改善值显著相关。Z5、R5、R5-R20、X5和Fres稳定期的改善值与通气功能参数FVC、FEV-和FEV-／FVC的改善值显著相关（P均〈0．05）。结论 COPD急性加重期较稳定期肺功能显著下降，肺过度充气和外周气道阻力增加是急性加重期肺功能恶化的主要原因。     

老年慢性阻塞性肺疾病患者血浆脂联素的水平

目的 分析老年慢性阻塞性肺疾病(COPD)患者血浆脂联素水平与C反应蛋白(CRP)、空腹血糖(FPG)、胰岛素抵抗(IR)及肥胖指标的关系.方法 选择住院的老年COPD患者60例,按病程分为急性加重期和临床稳定期,在不同时期测定血浆脂联素、CRP、FPG、胰岛素(FINS)、体重指数(BMI)、胰岛素抵抗指数(HOMA-IR).选择同期健康老年人50例作为对照.结果 COPD急性加重期及临床稳定期血浆脂联素均较对照组显著升高(P<0.01),临床稳定期血浆脂联素较急性加重期进一步升高(P<0.01);COPD急性加重期CRP、FPG、FINS、HOMA-IR显著高于临床稳定期及对照组(P<0.01);COPD临床稳定期FINS、HOMA-IR显著高于对照组(P<0.05);急性加重期脂联素与CRP、FPG、FINS、HOMA-IR、BMI均呈显著负相关(P<0.05或P<0.01).结论 老年COPD患者血浆脂联素水平升高并伴一定的胰岛素抵抗,脂联素在COPD稳定期进一步抬高,脂联素与CRP、FPG、IR及肥胖指标存在一定的相关性.     

瘦素与慢性阻塞性肺疾病病情严重程度的相关研究

目的 探讨瘦素在慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)炎症反应和营养不良发生中的作用以及对COPD患者病情严重程度的评估价值.方法 选择COPD急性加重期患者40例和健康老年人20名,记录吸烟情况,常规测定肺功能、血常规、血气分析、血清白蛋白(ALB)、身高和体质量,采用ELISA方法测定血清瘦索和白介素6(IL-6)水平,分析COPD急性加重期患者血清瘦素水平与IL-6水平、肺功能、血气指标、营养指标等的相关性,比较急性加重期和症状缓解期、健康对照组血清瘦素、IL-6水平以及吸烟状况、营养状况、病情严重程度不同的患者血清瘦素水平等.结果 ①COPD患者急性加重期的血清瘦素水平、IL-6水平、白细胞计数(WBC)、中性粒细胞百分比(NEUT%)、动脉血二氧化碳分压(PaCO_2)均明显高于症状缓解期和健康对照组,ALB、动脉血氧分压(PaO_2)、动脉血氧饱和度(SaO_2)则明显低于后者;②COPD患者急性加重期的血清瘦素水平与IL-6水平、WBC、NEUT%、PaCO_2呈正相关,与PaO_2、SaO_2、FEV_1占预计值百分比、ALB呈负相关,与FEV_1/FVC,BMI、吸烟指数无显著相关性;③营养状况不同组间比较血清瘦索水平无显著差异;④吸烟状况、病情严重程度不同组间比较血清瘦素水平有显著差异.结论 瘦素参与了COPD的全身炎症反应过程,可反映COPD患者病情严重程度.     

老年慢性阻塞性肺疾病患者血清瘦素水平与炎症及胰岛素抵抗的研究

目的分析老年慢性阻塞性肺疾病（COPD）患者血清瘦素水平与C反应蛋白（CRP）、空腹血糖（FBG）、胰岛素抵抗及体质量指数（BMI）的关系。方法选取住院的老年COPD患者60例,按病程分为急性加重期和临床稳定期,在不同时期测定空腹血清瘦素、CRP、FBG、胰岛素（FINS）、动脉血氧分压（PaO2）,测量身高、体质量,计算BMI、胰岛素抵抗指数（HOMA-IR）。选择同期健康老年人50例作为对照。结果 （1）COPD急性加重期血清瘦素、CRP、FBG、FINS、HOMA-IR均显著高于临床稳定期及对照组（P〈0.01）。（2）COPD临床稳定期FINS和HOMA-IR显著高于对照组（P〈0.05）。（3）各组中瘦素与FBG、FINS、HOMA-IR、BMI均呈显著正相关（P〈0.05或P〈0.01）;在急性加重期,瘦素还与CRP呈显著正相关（P〈0.01）,均衡FBG、FINS、HOMA-IR、BMI后进行偏相关分析,瘦素与CRP的相关性不再显著（P〉0.05）。结论老年COPD急性加重期患者血清瘦素、CRP水平升高并伴一定的胰岛素抵抗,瘦素与CRP、FBG、胰岛素抵抗及BMI存在一定的相关性,瘦素可能参与COPD急性加重期的炎症反应。     

血清白蛋白、前白蛋白水平在AECOPD的临床意义

目的探讨血清白蛋白(ALB)、血清前白蛋白(PA)水平在COPD患者急性加重期的临床意义。方法入选COPD急性加重期老年男性患者52例,比较其血清ALB、PA浓度与患者住院时间及心衰纠正时间的相关性,并分析ALB、PA与患者动脉血PH值、PaO2、PaCO2之间的关系。结果低ALB、低PA组患者的平均住院时间及心衰纠正时间明显延长,差异有统计学意义(P<0.05)。ALB正常组与ALB降低组血气PaCO2存在显著性差异(P<0.05),PA正常组与PA降低组血气PaO2存在显著性差异(P<0.05)。结论血清ALB、PA水平可作为评估COPD急性加重期患者预后的一项指标,PA明显降低更加提示预后不良。     

慢性阻塞性肺疾病患者lep-tin、IL-6的表达变化及其意义

目的观察慢性阻塞性肺疾病(慢阻肺)患者lep-tin、IL-6的表达情况,并分析其变化的临床意义。方法选取2013年5月~2015年5月在我院呼吸内科治疗的80例慢阻肺患者为研究对象,其中急性加重期的患者40例(急性加重期组),稳定期患者40例(稳定期组),同时选取40例健康志愿者作为对照组。比较不同时期的慢阻肺患者与对照组患者血清中lep-tin、IL-6含量、实验室指标以及肺功能指标的差异,采用Pearson相关分析法分析lep-tin、IL-6与实验室指标、肺功能的相关性。结果急性加重期和稳定期慢阻肺患者的lep-tin、IL-6和WBC、NEU%、CRP、Pa CO2等实验室指标明显均高于对照组,PH、Pa O2和Sa O2低于对照组;且急性加重期和稳定期患者的上述指标也存在明显差异;慢阻肺急性加重期和稳定期患者的肺功能均较差,且各项指标均低于对照组;急性加重期和稳定期慢阻肺患者的lep-tin、IL-6与WBC、NEU%、CRP、Pa CO2呈正相关,与PH、Pa O2和Sa O2呈负相关;急性加重期和稳定期慢阻肺患者的lep-tin、IL-6水平均与肺功能相关指标(6MWT、FVC、FEV1、FEV1/FVC、MMEF和PEF)均显著负相关。结论慢阻肺患者lep-tin、IL-6的表达较健康者高,且急性加重期更甚;lep-tin、IL-6水平与WBC、NEU%、CRP等实验室相关指标显著正相关,与PH、Pa O2、Sa O2指标以及肺功能相关指标显著负相关。提示lep-tin、IL-6水平对预测慢阻肺病情的严重程度有重要的指导意义。     

AECOPD患者白三烯B_4和α-肿瘤坏死因子的变化及治疗对其的影响

目的探讨COPD急性加重(AECOPD)患者白三烯B4和α-肿瘤坏死因子的改变和治疗对其的影响。方法随机抽取门诊稳定期COPD患者39例和住院的AECOPD患者43例,检测稳定期患者和AECOPD患者治疗前后血气分析、WBC、CRP、PROBNP、肺功能及血和诱导痰中LTB4和TNF-α的量。结果AECOPD患者PaCO2显著高于稳定期患者。两组肺功能无显著差异。WBC、CRP、PROBNP均无显著差异。AECOPD患者血LTB4和诱导痰LTB4均高于稳定期和治疗后。且治疗后LTB4显著低于治疗前;急性加重期患者治疗后血TNF-α显著低于稳定期患者,急性加重期患者治疗后诱导痰TNF-α明显低于治疗前和稳定期患者。结论 LTB4和TNF-α参与了AECOPD患者的发病过程,抗感染治疗可能降低LTB4,在诱导痰中表现最明显。而TNF-α的作用目前尚不明确。     

Phase Stability of Iron Nitride Fe4N at High Pressure—Pressure-Dependent Evolution of Phase Equilibria in the Fe–N System

Although the general instability of the iron nitride γ′-Fe₄N with respect to other phases at high pressure is well established, the actual type of phase transitions and equilibrium conditions of their occurrence are, as of yet, poorly investigated. In the present study, samples of γ′-Fe₄N and mixtures of α Fe and γ′-Fe₄N powders have been heat-treated at temperatures between 250 and 1000 °C and pressures between 2 and 8 GPa in a multi-anvil press, in order to investigate phase equilibria involving the γ′ phase. Samples heat-treated at high-pressure conditions, were quenched, subsequently decompressed, and then analysed ex situ. Microstructure analysis is used to derive implications on the phase transformations during the heat treatments. Further, it is confirmed that the Fe–N phases in the target composition range are quenchable. Thus, phase proportions and chemical composition of the phases, determined from ex situ X-ray diffraction data, allowed conclusions about the phase equilibria at high-pressure conditions. Further, evidence for the low-temperature eutectoid decomposition γ′→α+ε′ is presented for the first time. From the observed equilibria, a P–T projection of the univariant equilibria in the Fe-rich portion of the Fe–N system is derived, which features a quadruple point at 5 GPa and 375 °C, above which γ′-Fe₄N is thermodynamically unstable. The experimental work is supplemented by ab initio calculations in order to discuss the relative phase stability and energy landscape in the Fe–N system, from the ground state to conditions accessible in the multi-anvil experiments. It is concluded that γ′-Fe₄N, which is unstable with respect to other phases at 0 K (at any pressure), has to be entropically stabilised in order to occur as stable phase in the system. In view of the frequently reported metastable retention of the γ′ phase during room temperature compression experiments, energetic and kinetic aspects of the polymorphic transition γ′⇌ε′ are discussed.     

Emerging single-phase state in small manganite nanodisks

In complex oxides systems such as manganites, electronic phase separation (EPS), a consequence of strong electronic correlations, dictates the exotic electrical and magnetic properties of these materials. A fundamental yet unresolved issue is how EPS responds to spatial confinement; will EPS just scale with size of an object, or will the one of the phases be pinned? Understanding this behavior is critical for future oxides electronics and spintronics because scaling down of the system is unavoidable for these applications. In this work, we use La_0.325Pr_0.3Ca_0.375MnO₃ (LPCMO) single crystalline disks to study the effect of spatial confinement on EPS. The EPS state featuring coexistence of ferromagnetic metallic and charge order insulating phases appears to be the low-temperature ground state in bulk, thin films, and large disks, a previously unidentified ground state (i.e., a single ferromagnetic phase state emerges in smaller disks). The critical size is between 500 nm and 800 nm, which is similar to the characteristic length scale of EPS in the LPCMO system. The ability to create a pure ferromagnetic phase in manganite nanodisks is highly desirable for spintronic applications.Owing to strong coupling between spin, charge, orbital, and lattice (1, 2), different electronic phases often coexist spatially in strongly correlated materials known as electronic phase separation (EPS) (3, 4). For colossal magnetoresistance (CMR) manganites, EPS has been observed to have strong influence on the global magnetic and transport properties (5, 6). Regarding the physical origin of EPS, it has been shown theoretically that quenched disorder can lead to inhomogeneous states in manganites (1, 3, 7). Once long-range effects such as coulombic forces (8), cooperative oxygen octahedral distortions (9), or strain effects (10) are included, calculations show infinitesimal disorder (8, 11) or even no explicit disorder (10) may lead to EPS. Within a phenomenological Ginzburg–Landau theory, it has been shown that EPS is intrinsic in complex systems as a thermodynamic equilibrium state (12).Although the details of the origin of the EPS remain as a matter of dispute, its very existence as a new form of electronic state has been well accepted. The length scale of the EPS has been observed to vary widely from nanometers to micrometers depending on many parameters that can affect the competition between different electronic phases (13–20). It is thus of great interest to examine whether the EPS state still exists as the system is scaled down, especially when the spatial dimension of the system is smaller than the length scale of the EPS domains.In this work, we use La_0.325Pr_0.3Ca_0.375MnO₃ (LPCMO) as a prototype system to show a spatial confinement-induced transition from the EPS state to a single ferromagnetic phase state. The LPCMO system is chosen because of its well-known large length scale of EPS domains (approximately a micrometer) (21), which allows us to conveniently fabricate LPCMO epitaxial thin films into disks with diameters that are smaller than the EPS domain size. In LPCMO bulk (21) and thin films (6, 22), the EPS state was observed to be the low-temperature ground state. Using magnetic force microscope, we observe that the EPS state remains to be the ground state in disks with the size of 800 nm in diameter or larger but vanishes in the 500-nm-diameter disks whose size is distinctly smaller than the characteristic length scale of the EPS domains. In the 500-nm disks, only the ferromagnetic phase can be observed at all temperatures below Curie temperature T_c, indicating that the system is in a single-phase state rather than a EPS state. Our results further indicate that the large length scale EPS in the LPCMO system does not cost extra Coulomb energy, which otherwise should lead to a scaling down of EPS with decreasing size of the LPCMO disks (23, 24).LPCMO films with 60-nm thickness were epitaxially grown on SrTiO₃(001) substrates by pulsed-laser deposition. The substrates were kept at 780 °C in oxygen atmosphere of 5 × 10⁻³ millibars during growth. Unit cell by unit cell growth was achieved as indicated by oscillations of intensity of reflection high-energy electron diffraction (RHEED). The films were postannealed to 950 °C for 3 h in flowing oxygen to reduce oxygen vacancy and make sure that the films have the same magnetic properties as the bulk. The LPCMO disks with diameters from 500 nm to 20 μm were fabricated from the epitaxial thin films by electron beam lithography with a negative tone resist (for details, see the sample fabrication method and Fig. S1 in the Supporting Information). Magnetic properties of the LPCMO disk arrays were carried out using superconducting quantum interference device (SQUID) and magnetic force microscope (MFM) measurements.Open in a separate windowFig. S1.(A and B) Schematics of LPCMO disks samples for magnetic property measurement (A) and MFM mapping (B). (C) Optical microscopic image of LPCMO disk array with specific diameter. (D) SEM image of LPCMO disk sample for MFM imaging.A distinct signature of the EPS state in the LPCMO system is the thermal hysteresis for temperature-dependent magnetic and transport properties. Fig. 1 A–D shows temperature dependent magnetic properties of LPCMO disks with different diameters. To enhance the measuring signal for SQUID, we fabricate disk arrays for each selected diameter (the optical microscopic image shown in Fig. 1B, Inset for the 1-μm disk array). Fig. 1 A–D shows temperature-dependent magnetization measured under 1,000 Oe in-plane field for 7-μm, 1-μm, 800-nm, and 500-nm disk arrays, respectively. Thermal hysteresis can be observed for disk arrays with size down to 800 nm, reflecting the fact that ferromagnetic metallic (FMM) and charge order insulating (COI) phases coexist during the first-order phase transition (7, 25). For the 500-nm disk array, however, no thermal hysteresis can be observed. This observation implies that the EPS state may no longer exist in the system (7, 26).Open in a separate windowFig. 1.Temperature dependence of magnetization (black lines for cooling and red lines for warming) under 1,000 Oe (A–D) and initial magnetization (red lines) and hysteresis loop (black lines) (E–H) at 5 K of arrays of LPCMO disks with sizes of 7 μm (A and E), 1 μm (B and F), 800 nm (C and G), and 500 nm (D and H) in diameter and an area of 3 mm × 3 mm. (B, Inset) The optical microscopic image of d = 1 μm array. (C and D, Insets) Zoomed-in M vs. T loop around the thermal hysteresis region.The lack of EPS state in the 500-nm disk array is supported by the field-dependent magnetization measurements. Fig. 1 E–H shows in-plane initial magnetization curves and magnetic hysteresis loops (M-H loops) for the disk arrays measured at 5 K after zero-field cooling. For 800-nm or larger disk arrays, there is a clear difference between the initial magnetization curves and the corresponding M-H loops due to the coexistence of FMM and COI phases. When the magnetic field is applied from the initial state, the magnetization of the FMM phase first quickly aligns along the field direction, leading to the low field fast rise of the initial magnetization curve. With increasing field, the COI phase is melted and transits into the FMM phase. Once transited, the FMM phase will mostly stay even if the field is reduced, giving rise to the difference between initial magnetization curve and the M-H loop. The difference, however, becomes smaller with decreasing size. For the 500-nm disk array, the initial magnetization curve and the M-H loop virtually superimpose each other, indicating no melting of COI phase occurs. Both the temperature- and field-dependent magnetization measurements show a transition from the EPS state to a single FMM state with decreasing size of the disk, and the critical size should be between 500 nm and 800 nm.The transition from the EPS state to a single FMM state can be seen in MFM images shown in Fig. 2 (for MFM imaging details, see micromagnetic mapping method in Supporting Information). Fig. 2A shows morphological appearance of LPCMO disks with different sizes acquired by atomic force microscope (AFM). Fig. 2 B–D shows the corresponding MFM images of the LPCMO disks acquired at different temperatures under a perpendicular magnetic field of 1T. Here, the perpendicular magnetic field is applied to yield some perpendicular magnetization components for MFM imaging because the easy magnetization axis is in the plane. In the present color scale, the contrast below zero (red or black) represents FMM phase, whereas the contrast above zero (green or blue) represents nonferromagnetic phase [i.e., COI phase based on previous knowledge of the LPCMO system (21, 22)]. Apparently, except the 500-nm disk, all other disks show distinct features of the EPS state (i.e., the coexistence of the FMM and COI phases). Although the portion of FMM phase increases noticeably with decreasing temperature, the system stays in the EPS state even at 10 K. The typical length scale of the EPS domains is around a micrometer, which is consistent with previous reports (21, 27).Open in a separate windowFig. 2.(A) AFM images of LPCMO disks with sizes of 500 nm, 1 μm, 2 μm, 3.8 μm, 5 μm, and 7 μm in diameter. (B–D) The MFM images of LPCMO disks under 1T field (external magnetic field direction is pointing perpendicularly to the sample surface plane) taken at 10 K (B), 100 K (C), and 180 K (D). The sizes of disks in MFM images are adjusted and corrected to have same scales for each size with the help of scanning electron microscope (SEM) images (shown in Fig. S2) and dash lines show the approximate physical boundary of disks. The negative value in MFM image indicates attractive force and positive value indicates repulsive force.In stark contrast to the larger disks, the 500-nm disk does not exhibit any features of EPS in Fig. 2. Instead, the whole disk is in a ferromagnetic phase with a magnetization profile peaking in the center. To ensure that the EPS state is not diminished by the magnetic field applied during MFM imaging, we took MFM images of the 500-nm disk at 10 K under different perpendicular magnetic fields from 0T to 1T, as shown in Fig. 3A. At 0T, signals with opposite sign can only be seen on two sides of the disk along the marked line (MFM images of 4 disks shown in Fig. S3). This pattern is a typical MFM image for an in-plane ferromagnetic single domain, because only the two ends of an in-plane magnetic dipole yield perpendicular field gradient (with opposite signs) for the MFM tip to detect. Once a perpendicular field of 0.15T is applied, the in-plane magnetization is driven out of plane, leading to a center peaked MFM contour. The MFM signal increases with increasing field, as shown in Fig. 3B by the marked line profiles extracted from Fig. 3A.Open in a separate windowFig. 3.(A) MFM images of 500-nm disks at 10 K under different magnetic field. The lines show the path the line profile extracted. (B) Line profiles extracted from MFM images partly shown in Fig. 3A. (C) Simulated results corresponding to line-profiles in B. (D and E) The simulated Z-component of stray field 100 nm above sample disks and magnetic structure of 500-nm disks under a different magnetic field. In E, the direction and size of arrows show the direction and relative value of in-plane component of magnetization, and the color of disk indicates the value of Z-component of magnetization presented by ratio of Z-component to total magnetization, as shown in the color bar.Open in a separate windowFig. S3.MFM images of 500-nm disks taken at 10 K under zero field after zero-field cooling.The field-dependent behavior of the MFM contrast of the 500-nm disk is in qualitative agreement with micromagnetic simulations. Based on the MFM observation, the 500-nm disk is in an in-plane, single-domain state. Using this model as input, we performed micromagnetic simulation and obtained the Z-component of magnetic stray field distribution at 100 nm above sample surface (Fig. 3D; for details, see the micromagnetic simulation method in the Supporting Information), which is virtually the signal detected by MFM tip. The corresponding magnetic structures under different magnetic fields are shown in Fig. 3E. The marked line profiles extracted from simulation (Fig. 3D) are shown in Fig. 3C alongside with the experimental MFM line profiles (Fig. 3B). The subtle differences between Fig. 3B and Fig. 3C are likely caused by the fact that experimental MFM images are convoluted from signals of both the LPCMO disks and the MFM tips (∼100 nm in size). The consistency of MFM images and simulation confirms that the 500-nm disk is in a ferromagnetic single-domain state with an in-plane easy magnetization axis.Finally, we show that the 500-nm disk is in a single FMM state at all temperatures. Fig. 4 shows MFM images of the 500-nm disk acquired every 20 K, from 20 K to 200 K under 1,000 Oe. Other than the center-peaked FMM phase, no traces of COI phase can be observed. The MFM signal decreases with increasing temperature, which is consistent with the behavior of the temperature-dependent magnetization shown in Fig. 1. Considering the fact that we have never observed pure COI phase in the 500-nm disks, we believe this phenomenon may be caused by the existence of the ferromagnetic metallic edge state in the LPCMO system (22), which assists the 500-nm disk to be in pure ferromagnetic state when a single state is energetically preferred in the 500-nm disk.Open in a separate windowFig. 4.MFM images of 500-nm disks taken every 20 K, from 20 K to 200 K.In summary, we discovered a spatial confinement-induced transition from a EPS state featuring coexistence of FMM and COI phases to a single FMM state in the LPCMO system. The critical size for the transition is between 500 nm and 800 nm, which is similar to the characteristic length scale of the EPS state in the LPCMO system. Combining the MFM data and the micromagnetic simulation, we conclude that the 500-nm LPCMO disk is in a single-domain ferromagnetic state at all temperatures below T_c. A similar conclusion can be reached for 300-nm LPCMO disks (shown in Fig. S4), although it needs to be studied further whether a new state would emerge if the disk size becomes a few tens of nanometers or smaller. Our work opens a way to control EPS without external field or introducing strain and disorder, which is potentially useful to design electronic and spintronic devices in complex oxides systems.Open in a separate windowFig. S4.MFM images of 300-nm disks taken at different temperatures and magnetic fields.     

螺旋CT三期增强扫描在肾结核诊断和治疗中的价值

目的探讨螺旋CT三期增强扫描技术在肾结核诊断和疗效判定中的价值。方法对41例CT平扫怀疑肾结核的患者进行肾皮质期、实质期及延迟期三期增强扫描。结果皮质期及实质期扫描肾实质结核灶强化程度减低,呈不均匀低密度灶,并可见髓质脓腔,扩张肾盏呈“花瓣样”聚集排列,增厚肾盏壁强化;延迟期扫描对比剂进入扩张肾盏及髓质脓腔。结论螺旋CT三期增强扫描应作为肾结核诊断和疗效判定的常规检查方法。     

Barriers to vaccination in renal transplant recipients

Vaccine‐preventable diseases remain at the forefront of challenges in the long‐term care of renal transplant recipients (RTR). Although global vaccination campaigns targeting patients with end‐stage renal disease or RTR are standard, rates of vaccination among renal transplant candidates and RTRs remain suboptimal. We highlight the multifactorial barriers leading to low vaccination rates in this vulnerable population.     

Signatures and control of strong-field dynamics in a complex system

Controlling chemical reactions by light, i.e., the selective making and breaking of chemical bonds in a desired way with strong-field lasers, is a long-held dream in science. An essential step toward achieving this goal is to understand the interactions of atomic and molecular systems with intense laser light. The main focus of experiments that were performed thus far was on quantum-state population changes. Phase-shaped laser pulses were used to control the population of final states, also, by making use of quantum interference of different pathways. However, the quantum-mechanical phase of these final states, governing the system’s response and thus the subsequent temporal evolution and dynamics of the system, was not systematically analyzed. Here, we demonstrate a generalized phase-control concept for complex systems in the liquid phase. In this scheme, the intensity of a control laser pulse acts as a control knob to manipulate the quantum-mechanical phase evolution of excited states. This control manifests itself in the phase of the molecule’s dipole response accessible via its absorption spectrum. As reported here, the shape of a broad molecular absorption band is significantly modified for laser pulse intensities ranging from the weak perturbative to the strong-field regime. This generalized phase-control concept provides a powerful tool to interpret and understand the strong-field dynamics and control of large molecules in external pulsed laser fields.Can we find universal concepts to understand and control the response of atoms and molecules in interactions with strong laser fields? This question is at the heart of a vast number of experiments in time-resolved spectroscopy (1–30). The wide range of light sources spanning the spectral range from the X-ray (e.g., free-electron laser sources, synchrotrons) over the visible (conventional laser systems) to the far-infrared regime and covering the temporal range from nanosecond down to attosecond time scales created a wealth of new physics insight into quantum mechanisms, however mostly of simple systems in the gas phase (1–4). In chemistry, the generation of femtosecond laser pulses enabled the investigation of wave packet dynamics in molecules, as the induced vibrations occur on these time scales. Experiments focusing on, for instance, dissociation reactions, atom transfer, isomerization, or solvation dynamics have led to a deeper understanding of chemical bonds and their breakage dynamics and have opened and established the field of femtochemistry (5, 6). The aim is not only to study the light−matter interaction, but to use the obtained understanding of the processes to control the dynamics in complex molecules and, in the future, even to be able to control chemical reactions (7–10). Shaping the amplitude and phase of femtosecond laser pulses has been used, for example, to control the shape of wavefunctions in atomic systems (11) or to control and optimize the single-photon and multiphoton fluorescence in atoms such as cesium (12) and complex systems, e.g., dye molecules (13). Shaped pulses are also used in time-resolved coherent anti-Stokes Raman scattering (14–16) or 2D spectroscopy (17, 18). Adaptive shaping of the pulses via feedback control even allows the optimization of dynamical processes, e.g., the relative photodissociation yield of organometallic molecules (19), the relative two-photon fluorescence yield of dye molecules (20), and the energy transfer in light-harvesting molecules (21).However, the strong-field dynamics in complex systems, e.g., in the liquid phase, and its control have only recently moved into scientific focus (22–27). The dynamics of complex systems was thus far studied mainly in perturbative experiments such as transient absorption spectroscopy, which measures the evolution of a system after absorbing a single or a few photons. These experiments mainly measured population dynamics of excited states, without gaining access to the phases of the excited wavefunction coefficients. Even the phase-sensitive method of 2D/3D spectroscopy (28, 29), which evolved out of transient absorption spectroscopy, probes the perturbative third- or fifth-order response of the system and has not yet been used to systematically understand the strong-field response of a complex system. However, an important ingredient in approaching the ultimate goal of controlling chemistry is to get access to the phase of quantum-state coefficients and to analyze systematically the phase of the system’s response. In recent work, the phase of the dipole response after excitation was measured and controlled in a simple system, namely gaseous helium (31, 32). Transient absorption experiments were performed using extreme-UV attosecond pulses and 7-fs short visible to near-infrared (VIS/NIR) pulses, and the absorption was measured as a function of the time delay. The intensity of the femtosecond pulse could be varied in addition to the time delay. Thereby, the dipole response was systematically investigated as a function of the laser pulse intensity, ranging from the weak perturbative to the strong-field regime. Modifications of the absorption line shapes of helium from Fano to Lorentzian profiles and vice versa were observed with increasing VIS/NIR pulse intensity. These changes can be explained by an induced phase shift of the dipole response that is caused by the femtosecond pulse. Thus, the laser pulse intensity can be used as a control knob to modify the system’s response in a desired manner. In this work, we present the generalization of an atomic strong-field phase-control concept to complex systems in the liquid phase.     

血清瘦素在不同时期慢性阻塞性肺疾病患者中的表达及意义探讨

目的探讨慢性阻塞性肺疾病（COPD）患者不同时期血清瘦素水平的变化,以了解COPD患者炎症发生发展过程中瘦素的作用及其意义。方法选择COPD患者共53例,COPD急性加重期（Ⅰ组）26例,COPD缓解期（Ⅱ组）27例。正常对照组26例。测定和计算各组的多项营养指标,包括身高、体重、体重指数（BMI）、理想体重百分比（NM%）、体脂百分比（fat%）、三头肌皮皱厚度（TSF）、肩胛下皮皱厚度（SSF）、腹部皮皱厚度（ASF）、上臂中部臂围（MAC）、上臂肌围长（MAMC）、血清白蛋白（ALB）、前白蛋白（pro-ALB）、总淋巴细胞计数（LYM）。用放射免疫法测定53例COPD患者和26例正常人的血清瘦素。结果①COPD患者的各营养指标：BMI、NM%、fat%、TSF、SSF、ASF、MAC、MAMC、ALB、pro-ALB、LYM均显著低于正常对照组（P〈0.01）。②COPDⅠ组血清瘦素[（6.86±2.56）μg/L]显著高于正常组[（3.99±1.19）μg/L]与COPDⅡ组[（2.46±1.41）μg/L]（P〈0.01）;COPDⅡ组血清瘦素显著低于正常组（P〈0.01）。结论瘦素在急性加重期明显高于缓解期,因此可作为慢性阻塞性肺疾病急性加重期的炎性标志物。瘦素水平的表达可能是导致COPD患者能量代谢失衡,加重营养不良恶性循环的危险因素。     

A retrospective analysis of 1019 cases of tuberculous cervical lymphadenitis in a rural setup in 20 years

BackgroundThis article is to review cervical lymphadenitis due to tuberculosis (TB), their presentation, their aetiology, the methods used to diagnose them, the treatment modalities offered and the response to treatment.Methods1019 patients were diagnosed and treated for TB of the lymph nodes of the neck from 1st November 2001 to 31st August 2020 at a tertiary ENT hospital, Nadiad, Gujarat, India. Study consisted about 61% males and 39% females with the mean age being 37.3 years.ResultCommonest factor or habit among those diagnosed for tuberculous cervical lymphadenitis was consumption of unpasteurized milk. HIV and diabetes were the most common co-morbid conditions found with this disease. Swelling in the neck was most common clinical feature followed by loss of weight, formation of abscess, fever and fistula. Rifampicin resistance was found in 1.5% of patients among those tested for the same.ConclusionThe most commonly affected site for extra pulmonary TB is posterior triangle of neck than the anterior triangle. Patients with HIV and diabetes are at higher risk for the same. Testing for drug susceptibility has to be done due to increased resistant of drugs for extra pulmonary TB. GeneXpert and histopathological examination are important for its confirmation.     

Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks

The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs), is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM), the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diffusion coefficients are in the same order of magnitude (~10⁻¹⁶ m²·s⁻¹), whereas the diffusion coefficient of ferrocene in the empty framework is roughly 3-times smaller than in the MOF which is filled with ethanol or n-hexane.     

Evidence for electronic gap-driven metal-semiconductor transition in phase-change materials

Phase-change materials are functionally important materials that can be thermally interconverted between metallic (crystalline) and semiconducting (amorphous) phases on a very short time scale. Although the interconversion appears to involve a change in local atomic coordination numbers, the electronic basis for this process is still unclear. Here, we demonstrate that in a nearly vacancy-free binary GeSb system where we can drive the phase change both thermally and, as we discover, by pressure, the transformation into the amorphous phase is electronic in origin. Correlations between conductivity, total system energy, and local atomic coordination revealed by experiments and long time ab initio simulations show that the structural reorganization into the amorphous state is driven by opening of an energy gap in the electronic density of states. The electronic driving force behind the phase change has the potential to change the interconversion paradigm in this material class.