Negative-Index Refraction in a Lamellar Composite with Alternating Single Negative Layers

Negative-index refraction is achieved in a lamellar composite with epsilon-negative (ENG) and mu-negative (MNG) materials stacked alternatively. Based on the effective medium approximation, simultaneously negative effective permittivity and permeability of such a lamellar composite are obtained theoretically and further proven by full-wave simulations. Consequently, the famous left-handed metamaterial comprising split ring resonators and wires is interpreted as an analogy of such an ENG-MNG lamellar composite. In addition, beyond the effective medium approximation, the propagating field squeezed near the ENG/MNG interface is demonstrated to be left-handed surface waves with backward phase velocity.Comment: 18 pages, 6 figure

恶性胸腺瘤侵及肺动脉误诊为肺血栓栓塞症1例临床分析

Objective: To report 1 case was misdiagnosed as malignant thymoma (MTM) invading pulmonary artery and its diagnosis process, and to summarize the clinical and imaging features of MTM and its treatment. Methods: To retrospectively analyze the diagnostic process of 1 case of MTM invading bilateral pulmonary artery patients, and to have literature review. Results: Thymomas ranks third in mediastinum tumor incidence, which accounted for 21%~39% of MTM. MTM originated in thymic epithelial cells, divided into the invasive thymoma and thymic carcinoma, high malignancy, infiltration nearby tissue and organ. When MTM was very small, it can cause symptoms. The chest imaging is an important means of diagnosis of MTM. The vast majority of MTM as long as no contraindication, amnesia, all should be treated with operation as early as possible. Most researchers maintain postoperative adjuvant radiotherapy, chemotherapy in malignant thymoma patients according to the specific situation, which reduce the relapse and metastasis of the tumor. Conclusions: The clinical manifestations of MTM specificity is not strong, the main CT showed a mass with irregular, lobulated, along the vascular space and natural space invaded ediastinum, and surrounding tissue boundaries are not clear, enhanced scan showed heterogeneous enhancement of tumor. CT angiography can further identify sites and the relationship between MTM and heart, great vessels or bronchial and lung, raising the rate of accurate diagnosis. MTM is a dangerous disease with a relatively poor prognosis.目的  通过报告1例误诊为肺血栓栓塞症的侵及双侧肺动脉的恶性胸腺瘤患者的诊断过程，总结恶性胸腺瘤的临床、影像学特征及诊断治疗方法。方法  回顾性分析1例侵及双侧肺动脉的恶性胸腺瘤患者的诊断过程，并复习有关文献。结果  胸腺瘤居纵膈肿瘤发病率的第三位，恶性胸腺瘤占其中的21%～39%，其起源于胸腺上皮细胞，分为侵袭性胸腺瘤和胸腺癌两种类型，恶性度较高，易浸润附近组织器官。恶性胸腺瘤较小时即可出现症状。胸部影像学检查则是诊断恶性胸腺瘤的重要手段。绝大多数恶性胸腺瘤只要无禁忌症，均应尽早手术治疗。多数研究者主张术后根据具体情况辅以放射治疗、化学治疗，可以延缓肿瘤的转移与复发。结论  恶性胸腺瘤临床表现特异性不强，主要的CT表现为肿块形态不规则，呈分叶状，多沿血管间隙及纵膈固有间隙侵犯，与周围组织分界不清，增强扫描肿瘤呈不均匀强化。CT心血管造影能进一步鉴别肿瘤的相通部位以及心脏大血管或支气管、肺脏等的关系，提高确诊率。恶性胸腺瘤病情凶险，预后相对较差

Diverse biological effects of glycosyltransferase genes from Tartary buckwheat

Background: Tartary buckwheat (Fagopyrum tataricum) is an edible cereal crop whose sprouts have been marketed and commercialized for their higher levels of anti-oxidants, including rutin and anthocyanin. UDP-glucose flavonoid glycosyltransferases (UFGTs) play an important role in the biosynthesis of flavonoids in plants. So far, few studies are available on UFGT genes that may play a role in tartary buckwheat flavonoids biosynthesis. Here, we report on the identification and functional characterization of seven UFGTs from tartary buckwheat that are potentially involved in flavonoid biosynthesis (and have varying effects on plant growth and development when overexpressed in Arabidopsis thaliana.) Results: Phylogenetic analysis indicated that the potential function of the seven FtUFGT proteins, FtUFGT6, FtUFGT7, FtUFGT8, FtUFGT9, FtUFGT15, FtUFGT40, and FtUFGT41, could be divided into three Arabidopsis thaliana functional subgroups that are involved in flavonoid biosynthesis of and anthocyanin accumulation. A significant positive correlation between FtUFGT8 and FtUFGT15 expression and anthocyanin accumulation capacity was observed in the tartary buckwheat seedlings after cold stress. Overexpression in Arabidopsis thaliana showed that FtUFGT8, FtUFGT15, and FtUFGT41 significantly increased the anthocyanin content in transgenic plants. Unexpectedly, overexpression of FtUFGT6, while not leading to enhanced anthocyanin accumulation, significantly enhanced the growth yield of transgenic plants. When wild-type plants have only cotyledons, most of the transgenic plants of FtUFGT6 had grown true leaves. Moreover, the growth speed of the oxFtUFGT6 transgenic plant root was also significantly faster than that of the wild type. At later growth, FtUFGT6 transgenic plants showed larger leaves, earlier twitching times and more tillers than wild type, whereas FtUFGT15 showed opposite results. Conclusions: Seven FtUFGTs were isolated from tartary buckwheat. FtUFGT8, FtUFGT15, and FtUFGT41 can significantly increase the accumulation of total anthocyanins in transgenic plants. Furthermore, overexpression of FtUFGT6 increased the overall yield of Arabidopsis transgenic plants at all growth stages. However, FtUFGT15 shows the opposite trend at later growth stage and delays the growth speed of plants. These results suggested that the biological function of FtUFGT genes in tartary buckwheat is diverse

Tetra­kis(μ-phenoxy­acetato-κ2 O:O′)bis­[(1,10-phenanthroline-κ2 N,N′)manganese(II)] methanol hemisolvate

The title complex, [Mn2(C8H7O3)4(C12H8N2)2]·0.5CH3OH, is a carboxyl­ate-bridged dinuclear MnII complex with four phenoxy­acetate ions and two 1,10-phenanthroline mol­ecules as ligands. Each of the four phenoxy­acetate anions bridges the pair of Mn atoms. The asymmetric unit is completed by a half-occupancy methanol solvent mol­ecule. Face-to-face π–π stacking inter­actions between the aromatic rings of 1,10-phenanthroline molecules belonging to adjacent Mn2 complexes, with an inter­planar separation of circa 3.4 Å, and weak C—H⋯O hydrogen bonds connect the dinuclear units into a three-dimensional supra­molecular framework

Propagation characteristics and identification of type I cracks by the extended finite element method combined with modal analysis

Extended finite element frame based on Abaqus is applied to research the crack propagation problem of two-dimensional long rectangular thin plate. Presuppose type I crack with different horizontal locations and longitudinal dimensions, the propagation characteristics of the edge crack is discussed with the objects of structural flexibility of the thin plate, crack propagation length and plastic zone of crack tip etc. The results indicate that the horizontal location of the initial crack has a small influence on the crack propagation characteristics, and it only affects the local flexibility of the thin plate as well as the dimension and shape of plastic zone of crack tip. The longitudinal dimension of the initial crack obviously nonlinear influence on various parameters of the crack propagation characteristics. In view of the disastrous consequence of crack propagation, the vibration characteristics of the thin plate with different crack dimensions and crack locations are discussed based on the experiment and simulation modal analysis on the thin plate, thus providing basis for prior estimation and control for crack generation and propagation

Psychological Effects of False-Positive Results in Expanded Newborn Screening in China

Objectives: As more families participate expanded newborn screening for metabolic disorders in China, the overall number of false positives increases. Our goal was to assess the potential impact on parental stress, perceptions of the child’s health, and family relationships. Methods: Parents of 49 infants with false-positive screening results for metabolic disorders in the expanded newborn screening panel were compared with parents of 42 children with normal screening results. Parents first completed structured interview using likert scales, closed and open questions. Parents also completed the parenting stress index. Results: A total of 88 mothers and 41 fathers were interviewed. More mothers in the false-positive group reported that their children required extra parental care (21%), compared with 5 % of mothers in the normal-screened group (P,0.001). 39 % of mothers in the false-positive group reported that they worry about their child’s future development, compared with 10 % of mothers in the normal-screened group (P,0.001). Fathers in the false-positive group did not differ from fathers in the normal-screened group in reporting worry about their child’s extra care requirements, and their child’s future development. Children with false-positive results compared with children with normal results were triple as likely to experience hospitalization (27%vs 9%, respectively; P,0.001). Conclusions: The results showing false-positive screening results may affect parental stress and the parent-chil

Optical loss compensation in a bulk left-handed metamaterial by the gain in quantum dots

A bulk left-handed metamaterial with fishnet structure is investigated to show the optical loss compensation via surface plasmon amplification, with the assistance of a Gaussian gain in PbS quantum dots. The optical resonance enhancement around 200 THz is confirmed by the retrieval method. By exploring the dependence of propagation loss on the gain coefficient and metamaterial thickness, we verify numerically that the left-handed response can endure a large propagation thickness with ultralow and stable loss under a certain gain coefficient.Comment: 6 pages with 4 figure