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71.
目的:对比研究撕脱皮肤反取薄中厚皮片与常规切取薄中厚皮片在治疗皮肤撕脱伤中的移植效果。方法:选取2008年6月~2012年6月就诊的52例四肢皮肤撕脱伤患者为研究对象,其中23例因撕脱皮肤毁损严重无法利用,只能采用常规切取薄中厚皮片游离移植修复撕脱伤创面,其余29例利用撕脱皮肤反取制备薄中厚皮片,全部薄中厚皮片打孔直径1cm,术后均采取加压包扎。结果:所有移植皮片均成活,常规切取薄中厚皮片移植的23例患者中,Ⅰ期愈合者21例,Ⅰ期愈合率为91.3%;撕脱皮肤反取薄中厚皮片的29例患者中,Ⅰ期愈合者24例,Ⅰ期愈合率为82.8%。结论:常规切取薄中厚皮片移植与撕脱皮肤反取薄中厚皮片移植的Ⅰ期愈合率相仿,临床应尽可能利用撕脱皮肤反取制备薄中厚皮片移植修复撕脱伤创面,如撕脱皮肤难以利用则应选用薄中厚皮片移植修复。  相似文献   
72.
Brilliant animal colors often are produced from light interacting with intricate nano-morphologies present in biological materials such as butterfly wing scales. Surveys across widely divergent butterfly species have identified multiple mechanisms of structural color production; however, little is known about how these colors evolved. Here, we examine how closely related species and populations of Bicyclus butterflies have evolved violet structural color from brown-pigmented ancestors with UV structural color. We used artificial selection on a laboratory model butterfly, B. anynana, to evolve violet scales from UV brown scales and compared the mechanism of violet color production with that of two other Bicyclus species, Bicyclus sambulos and Bicyclus medontias, which have evolved violet/blue scales independently via natural selection. The UV reflectance peak of B. anynana brown scales shifted to violet over six generations of artificial selection (i.e., in less than 1 y) as the result of an increase in the thickness of the lower lamina in ground scales. Similar scale structures and the same mechanism for producing violet/blue structural colors were found in the other Bicyclus species. This work shows that populations harbor large amounts of standing genetic variation that can lead to rapid evolution of scales’ structural color via slight modifications to the scales’ physical dimensions.Organisms produce colors in two basic ways: by synthesizing pigments that selectively absorb light of certain spectral bands so that only light outside the absorption bands is backscattered (chemical color) or by developing nanomorphologies that enhance the reflection of light of certain wavelengths by interference (physical color or structural color). Structural colors play major roles in natural and sexual selection in many species (1) and have a broad range of applications in color display, paint, cosmetics, and textile industries (2). Structural color surveys across widely divergent species have revealed a large diversity of color-producing mechanisms (39). However, there has been a lack of systematic study and comparison of how different colors from closely related species or within populations of a single species evolve, even though these colors can vary dramatically. By examining how these species/populations evolve different colors, it is possible to identify the minimal amount of morphological change that results in significant color variation. Furthermore, this research may serve as an inspiration for future application of similar evolutionary principles to the design of photonic devices for color tuning, light trapping, or beam steering (2, 1020). From an evolutionary biology point of view, we are curious to examine how structural colors respond to selection pressure and whether there is sufficient standing genetic variation in natural populations to allow the rapid evolution of novel colors. Here we focus on determining the morphological changes and the physical mechanisms that cause the evolution of violet structural color in populations of a single species and also across different species within a single genus of butterflies.We focus on the genus Bicyclus (Lepidoptera: Nymphalidae), composed of more than 80 species that predominantly exhibit brown color along with marginal eyespots. Some Bicyclus species, however, have independently evolved transverse bands of bright violet/blue structural color on the dorsal surface of the forewings (black asterisks in Fig. 1A) (21, 22). One species, Bicyclus anynana, has become a model species amenable to laboratory rearing, and multiple aspects of its marginal eyespots (size, relative width of the color rings, shape) have been altered by artificial selection (2327). However, change of color (hue), either pigmentary or structural, via artificial selection has not been reported. B. anynana does not exhibit bright violet coloration on its wings and therefore provides an excellent opportunity for investigating whether there is genetic potential to produce violet color upon directed selection. We investigated this potential by performing an artificial selection experiment in B. anynana that targeted the color of the specific dorsal wing region that evolved violet/blue coloration in other members of the genus (Fig. 1 BG).Open in a separate windowFig. 1.Structural color in Bicyclus butterflies and basic wing scale morphology. (A) A phylogenetic estimate of Bicyclus butterfly relationships (modified from ref. 41) illustrating the evolution of color in the genus. The black asterisks mark two clades that evolved violet/blue color independently, represented here by B. sambulos and B. medontias. (BD) Dorsal wing images of B. sambulos, B. anynana (the region used for artificial selection is marked by white asterisk), and B. medontias. (EG) Graphs of reflectance spectra of the blue/violet wing band showing reflectance peaks in the 400–450 nm range and in the brown-colored homologous region in B. anynana with a UV reflectance peak centered at 300 nm (colored arrows). (H) 3D illustration of the wing and scales in the selected wing area of B. anynana. (I) Magnified view of the ripped region in H showing how cover (c; brown) and ground (g; green) scales are attached to the wing membrane (m, pink) and alternate along rows. Scales on the other (ventral) side of the wing membrane are visible also. (J) Cross-sectional view of a single scale showing the trabeculae (T) connecting the lower lamina (LL) to the upper lamina that includes ridges (R), microribs (Mr), and crossribs (Cr). Windows (W) are the spaces between the ridges and crossribs. Cover and ground scales have the same basic morphology. [llustrations in HJ courtesy of Katerina Evangelou (Central Saint Martin’s College, London).]B. anynana, like other butterflies, has two types of scales, cover and ground, which alternate within a row with cover scales partially covering the ground scales and the point where both scales attach to the wing membrane (Fig. 1 H and I and Fig. S1) (28). Both cover and ground scales contain a lower lamina with a continuous smooth surface below a region composed of longitudinal ridges and crossribs, collectively referred to as the “upper lamina” and connected to the lower lamina via pillars called “trabeculae” (Fig. 1J and Fig. S1) (6). Previous studies on butterflies showed that structural color can be produced by interference with light reflected from the overlapping lamella that build the longitudinal ridges, from microribs protruding from the sides of the longitudinal ridges, or from the lower lamina, which can vary in thickness and patterning (Fig. 1J) (29, 30). However, it is not clear how the violet/blue color is produced in members of the two Bicyclus clades that separately evolved this color, whether B. anynana can be made to evolve the same violet/blue color via artificial selection, and whether it will generate the color in the same way as the other species. To answer these questions, we conducted detailed optical characterization and structural analysis of butterfly wing scales from three separate species and artificially evolved populations of Bicyclus to illustrate how color is generated and how it has evolved.  相似文献   
73.
74.
Extramedullary multiple myeloma (EMM) involving the liver as a focal space‐occupying lesion is very rare, especially in the patients with cirrhosis. Here, we report a case of EMM in the liver and periportal lymph node, diagnosed by endoscopic ultrasound guided‐fine‐needle aspiration (EUS‐FNA). A 57‐year‐old male patient, with history of cirrhosis, presented with abdominal pain and pancytopenia. The abdominal magnetic resonance imaging (MRI) demonstrated a 6.5 cm left hepatic mass with a 1.1 cm malignant‐appearing periportal lymph node and diffuse osseous lesions. The cytology specimens from the hepatic mass and the periportal lymph node were obtained through EUS‐FNA without rapid on‐site evaluation (ROSE). The thin‐layer preparations (ThinPrep) showed abundant plasmacytoid cells, which were confirmed to be Kappa‐restricted neoplastic plasma cells by the cell block preparations. Later, his serum level of Kappa light chain was found significantly elevated by flow cytometry, which was identified as monoclonal IgA Kappa light chain by serum protein electrophoresis (SPEP) with immunofixation. The patient was diagnosed as IgA multiple myeloma with extramedullary involvement of the liver and periportal lymph node. This is the first case showing the ThinPrep cytomorphologic features of EMM in the liver and periportal lymph node. This case highlights the importance of distinguishing plasma cells from being hepatocytes and lymphocytes on the ThinPrep and also emphasizes the utility of the cell block in the diagnosis of plasma cell neoplasm.  相似文献   
75.
目的 建立胸腔积液结核分枝杆菌(Mycobacterium tuberculosis,M.tb)复苏因子薄层琼脂(Rpfs-TLA)快速培养法并评估其临床应用价值。方法 收集2016年7月至2018年11月北京胸科医院103例结核性胸膜炎和34例其他胸膜疾病患者的胸腔积液,经过离心、消化处理后进行M.tb复苏因子薄层琼脂和普通薄层琼脂培养,比较Rpfs-TLA与普通TLA培养M.tb的阳性率、平均报阳时间、菌落形成单位数的组间差异。结果 胸腔积液Rpfs-TLA培养组和普通TLA对照组M.tb的阳性率分别为43.7%和29.1%,差异有统计学意义(χ2=54.56,P<0.001)。Rpfs-TLA培养显微镜下微菌落与肉眼可视菌落平均报告时间为11.87 d和18.13 d,差异有统计学意义(t=31.82,P<0.001)。Rpfs-TLA与普通TLA培养显微镜下微菌落的平均报告时间为11.87 d和20.60 d,差异有统计学意义(t=16.62,P<0.001)。Rpfs-TLA诊断结核性胸膜炎的灵敏度为43.7%,特异度为100%,准确度...  相似文献   
76.
We report on the formation of Ag-containing ZrCuAlNi thin film metallic glass (nano)composites by a hybrid direct-current magnetron sputtering and high-power pulsed magnetron sputtering process. The effects of Ag content, substrate temperature and substrate bias potential on the phase formation and morphology of the nanocomposites were investigated. While applying a substrate bias potential did not strongly affect the morphological evolution of the films, the Ag content dictated the size and distribution of Ag surface segregations. The films deposited at low temperatures were characterized by strong surface segregations, formed by coalescence and Ostwald ripening, while the volume of the films remained featureless. At higher deposition temperature, elongated Ag segregations were observed in the bulk and a continuous Ag layer was formed at the surface as a result of thermally enhanced surface diffusion. While microstructural observations have allowed identifying both surface and bulk segregations, an indirect method for detecting the presence of Ag segregations is proposed, by measuring the electrical resistivity of the films.  相似文献   
77.
Epitaxial Ni-Mn-Ga thin films have been extensively investigated, due to their potential applications in magnetic micro-electro-mechanical systems. It has been proposed that the martensitic phase in the <1 1 0>A-oriented film is much more stable than that in the <1 0 0>A-oriented film. Nevertheless, the magnetic properties, microstructural features, and crystal structures of martensite in such films have not been fully revealed. In this work, the <1 1 0>A-oriented Ni51.0Mn27.5Ga21.5 films with different thicknesses were prepared by epitaxially growing on Al2O3(1 1 2¯ 0) substrate by magnetron sputtering. The characterization by X-ray diffraction technique and transmission electron microscopy revealed that all the Ni51.0Mn27.5Ga21.5 films are of 7M martensite at the ambient temperature, with their Type-I and Type-II twinning interfaces nearly parallel to the substrate surface.  相似文献   
78.
The study of hydrogen storage properties of Mg-based thin films is of interest due to their unique composition, interface, crystallinity, and high potential for use in hydrogen-storage systems. Alloying Mg with Al leads to the destabilization of the magnesium hydride reducing the heat of reaction, increases the nucleation rate, and decreases the dehydriding temperature. The purpose of our study is to reveal the role of the aluminum atom addition in hydrogen adsorption and accumulation in the Mg-H solid solution. Ab initio calculations of aluminum and hydrogen binding energies in magnesium were carried out in the framework of density functional theory. Hydrogen distribution and accumulation in Mg and Mg-10%Al thin films were experimentally studied by the method of glow-discharge optical emission spectroscopy and using a hydrogen analyzer, respectively. It was found that a hydrogen distribution gradient is observed in the Mg-10%Al coating, with more hydrogen on the surface and less in the bulk. Moreover, the hydrogen concentration in the Mg-10%Al is lower compared to Mg. This can be explained by the lower hydrogen binding energy in the magnesium-aluminum system compared with pure magnesium.  相似文献   
79.
Performance of a perovskite solar cell is largely influenced by the optoelectronic properties of metal halide perovskite films. Here we study the influence of cesium concentration on morphology, crystal structure, photoluminescence and optical properties of the triple cation perovskite film. Incorporation of small amount (x = 0.1) of cesium cations into Csx(MA0.17FA0.83)1−x Pb(I0.83Br0.17)3 leads to enhanced power conversion efficiency (PCE) of the solar cell resulting mainly from significant rise of the short-current density and the fill factor value. Further increase of Cs concentration (x > 0.1) decreases the film’s phase purity, carrier lifetime and correspondingly reduces PCE of the solar cell. Higher concentration of Cs (x ≥ 0.2) causes phase segregation of the perovskite alongside with formation of Cs-rich regions impeding light absorption.  相似文献   
80.
以孤立性血尿为表现的薄基底膜肾病54例分析   总被引:2,自引:0,他引:2  
目的探讨薄基底膜肾病(TBMN)的临床表现和病理特点。方法对54例临床表现为孤立性血尿、经肾活检证实的TBMN患儿进行分析。所有患儿行肾穿刺,分别进行光镜、免疫荧光和电镜观察及基底膜厚度测定。采用间接免疫荧光法检测皮肤基底膜(EBM)Ⅳ型胶原α1、α5和肾小球基底膜(GBM)Ⅳ型胶原α1、α3和α5链表达。结果所有病例肾小球基底膜弥漫性均匀性变薄,无基底膜分层、撕裂等改变,部分病例存在节段性足突消失。4段基底膜厚度分别为(170.7±45.0)nm、(175.6±47.9)nm、(181.8±36.3)nm和(170.0±32.9)nm。EBM和 GBMⅣ型胶原α链检测,发现异常2例。结论薄基底膜肾病主要表现为孤立性血尿,确诊有赖肾活检电镜基底膜厚度测定,须与Alport综合征鉴别。  相似文献   
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