用中国仓鼠V_(79)细胞HGPRT位点正向突变试验检测饮用水的致突变性

用国产H-103树脂吸附的武汉D水厂水源水与出厂水的非挥发性、非极性有机浓集物,在不加代谢活化系统条件下,均能诱发中国仓鼠胚胎肺成纤维细胞(V79)次黄嘌呤鸟嘌呤磷酸核糖转移酶(HGPRT)位点的正向突变。出厂水2、4、6升/瓶三种浓度的致突变率分别为空白对照的4.25、14.68、22.75倍;水源水4升/瓶浓度对细胞也有致突变性。提示武汉D水厂的水源水与出厂水中存在着对哺乳动物细胞的直接致突变物,且出厂水中致突变物的活性更强。     

Generation of TIM3 inhibitory single-domain antibodies to boost the antitumor activity of chimeric antigen receptor T cells

Targeting inhibitory immune checkpoint molecules has significantly altered cancer treatment regimens. T cell immunoglobulin and mucin domain 3 (TIM3) is one of the major inhibitory immune checkpoints expressed on T cells. Blocking the engagement of TIM3 and its inhibitory ligand galectin-9 may potentiate the effects of immunotherapy or overcome the adaptive resistance to the therapeutic blockade of programmed cell death protein 1, cytotoxic T-lymphocyte-associated protein 4, B- and T-lymphocyte attenuator and lymphocyte-activation gene 3, amongst others, as each of these immune checkpoints harbors unique properties that set it apart from the rest. Heavy chain variable fragment (VH)-derived single-domain antibodies (sdAbs) represent a class of expanding drug candidates. These sdAbs have unique advantages, including their minimal size in the antibody class, ease of expression, broad scope for modular structure design and re-engineering, and excellent tumor penetration. In the present study, two sdAbs, TIM3-R23 and TIM3-R53, were generated by immunizing rabbits with the recombinant extracellular domain of TIM3 and applying phage display technology. These sdAbs were easily expressed in mammalian cells. The purified sdAbs were able to bind to both recombinant and cell surface TIM3, and blocked it from binding to the ligand galectin-9. In vivo studies demonstrated that TIM3-R53 was able to potentiate the antitumor activity of chimeric antigen receptor T cells that targeted mesothelin. In conclusion, the results of the present study suggested that TIM3-R53 may be a novel and attractive immune checkpoint inhibitor against TIM3, which is worthy of further investigation.     

品管圈在脊柱骨科手术中的应用

目的探讨品管圈管理在脊柱骨科手术中的护理应用价值。方法 2015年1-6月,采用便利抽样法选择冀中能源邢台矿业集团总医院住院拟行脊柱外科手术患者90例为对照组。同法选择2015年7-12月的90例患者为观察组。对照组予以常规护理,2015年7月,开展品管圈活动,分析脊柱骨科手术中存在的护理问题发生原因,制定改进措施;观察组患者按改进后的护理措施进行日常护理。比较两组患者的手术护理质量、护理满意度以及护理人员能力。结果观察组在医护配合、护理文书、器械维护、标本送检、患者安全等护理质量方面的评分均高于对照组,差异均有统计学意义(均P0.05)。观察组患者的满意度高于对照组,差异有统计学意义(P0.05)。观察组护士开展活动后的护理理论培训、护理技能培训成绩明显高于活动前,差异有统计学意义(P0.05)。结论品管圈管理在脊柱骨科手术护理应用中能够有效提高护理工作质量,提升了护理人员能力,增强了手术室护理品质以及患者满意度。     

Endohedral gallide cluster superconductors and superconductivity in ReGa5

We present transition metal-embedded (T@Ga_n) endohedral Ga-clusters as a favorable structural motif for superconductivity and develop empirical, molecule-based, electron counting rules that govern the hierarchical architectures that the clusters assume in binary phases. Among the binary T@Ga_n endohedral cluster systems, Mo₈Ga₄₁, Mo₆Ga₃₁, Rh₂Ga₉, and Ir₂Ga₉ are all previously known superconductors. The well-known exotic superconductor PuCoGa₅ and related phases are also members of this endohedral gallide cluster family. We show that electron-deficient compounds like Mo₈Ga₄₁ prefer architectures with vertex-sharing gallium clusters, whereas electron-rich compounds, like PdGa₅, prefer edge-sharing cluster architectures. The superconducting transition temperatures are highest for the electron-poor, corner-sharing architectures. Based on this analysis, the previously unknown endohedral cluster compound ReGa₅ is postulated to exist at an intermediate electron count and a mix of corner sharing and edge sharing cluster architectures. The empirical prediction is shown to be correct and leads to the discovery of superconductivity in ReGa₅. The Fermi levels for endohedral gallide cluster compounds are located in deep pseudogaps in the electronic densities of states, an important factor in determining their chemical stability, while at the same time limiting their superconducting transition temperatures.The prediction of new superconductors remains an elusive goal. Although one can analyze the superconductivity, once discovered, through materials physics-based “k-space” pictures based on Fermi surfaces, energy band dispersions, and effective interactions, often it is chemists, whose viewpoint is instead from “real space” rather than k-space, who find such superconductors in the first place (1, 2). Given the difficulty in making extrapolations between the physics of superconductivity and the chemical stability of compounds that will be superconducting, there are as many strategies for finding new superconductors as there are researchers looking for them (3–5). Most such search strategies fail, because the interactions that give rise to superconductivity can also lead to competing electronic states or can be strong enough to tear potential compounds apart (6, 7).

Table 1.

Selected Binary Phases with Endohedral Ga-clusters

Polytypism,polymorphism, and superconductivity in TaSe2?xTex

Polymorphism in materials often leads to significantly different physical properties—the rutile and anatase polymorphs of TiO₂ are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer-stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivity of TaSe₂, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access two stable polytypes and two stable polymorphs in the TaSe_2−xTe_x solid solution and find that the 3R polytype shows a superconducting transition temperature that is between 6 and 17 times higher than that of the much more commonly found 2H polytype. The reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of T_c on subtle differences in the characteristics of the single layers present or from a surprising effect of the layer-stacking sequence on electronic properties that are typically expected to be dominated by the properties of a single layer in materials of this kind.The MX₂ layered transition-metal dichalcogenides (TMDCs, M = Mo, W, V, Nb, Ta, Ti, Zr, Hf, or Re and X = Se, S, or Te), have long been of interest due to the rich electronic properties that emerge due to their low dimensionality (1–9). Structurally, these compounds can be regarded as having strongly bonded (2D) X–M–X layers, with M in either trigonal prismatic or octahedral coordination with X, and weak interlayer X–X bonding of the van der Waals type. Many of these materials manifest charge-density waves and competition between charge-density waves (CDWs) and superconductivity, e.g., refs. 5–9. Among the TMDCs, the 2H (H: hexagonal) polytype of tantalum diselenide (2H-TaSe₂) is considered one of the foundational materials (8–18), showing a transition from a metallic phase to an incommensurate charge-density wave (ICDW) phase at 123 K, followed by a “lock-in” transition to a commensurate charge-density wave (CCDW) phase at 90 K. It finally becomes a superconductor with a rather low transition temperature (T_c) of 0.15 K. Although detailed studies have been performed on the physics of CDWs and superconductivity in 2H-TaSe₂ (16–18), a comparative study of the superconductivity of the polytypes and polymorphs of TaSe₂ from the chemical perspective has not been done.TaSe₂ is highly polymorphic, possibly the most polymorphic of the TMDCs (19). In some of its forms, notably the 2H and 3R (R: rhombohedral) polytypes (Fig. 1A), Ta is found in trigonal prismatic coordination in Se-Ta-Se layers that are stacked along the c axis of the hexagonal (or rhombohedral) cell. The 2H and 3R polytypes differ only in their stacking periodicity—the structure repeats after two layers in the 2H form and three layers in the 3R form (20–22). The 3R form can be synthesized, but it is not the stable variant (the 2H form is) and so has been the subject of little study. In one of the other polymorphs, the 1T (T: trigonal) type, Ta is found in octahedral coordination in the Se-Ta-Se layers and the layer stacking along the c axis of the trigonal cell such that the structure repeats after only one layer (23) (Fig. 1A). Again, the 1T form has not been the subject of much study. Here we show that the 3R and 1T polymorphs are both quite stable in the TaSe_2−xTe_x system and that they are both superconducting. For pure TaTe₂, the monoclinic structure is 1T based (Fig. 1A), but is distorted such that there are two nonequivalent Ta and three nonequivalent Te positions in the unit cell (24); we find TaSe_2−xTe_x in this polymorph to be nonsuperconducting down to 0.4 K.Open in a separate windowFig. 1.Structural characterization and analysis of the polytypes and polymorphs of TaSe_2−xTe_x. (A) The crystal structures of 2H-TaSe₂, 3R-TaSe_1.65Te_0.35, 1T-TaSeTe, and monoclinic TaTe₂. (B) Powder X-ray diffraction pattern for 3R-TaSe_1.65Te_0.35. Inset shows the reduced lattice parameter ratio, (c/n)/a, where n = number of layers per cell, for 2H-TaSe₂ (38) and 3R-TaSe_2−xTe_x. (C) Powder X-ray diffraction pattern for 1T-TaTeSe. Inset shows the reduced lattice parameter ratio, (c/n)/a, for 1T-TaSe_2−xTe_x. (D) The variation of in-plane lattice parameter, a, with x for 2H-, 3R-, and 1T-TaSe_2−xTe_x. (E) The variation of reduced stacking-direction lattice parameter, c/n, with x for 2H-, 3R-, and 1T-TaSe_2−xTe_x. (F) The variation of the TaX₂ slab thickness, ((c·(∆z)), with x for 2H-, 3R-, and 1T-TaSe_2−xTe_x. (G) The variation of the van der Waals gap (vdWG) thickness with x for 2H-, 3R-, and 1T-TaSe_2−xTe_x.We report the structures and superconducting properties of TaSe_2−xTe_x for 0 ≤ x ≤ 2. The 2H, 3R, 1T, and monoclinic distorted 1T-structure forms were successfully synthesized. Only a small amount of Te doping (x = 0.02) changes 2H-TaSe₂ into the 3R polytype. Within the 3R polytype, TaSe_2−xTe_x shows the coexistence of a CDW and superconductivity above 0.4 K for 0.1 ≤ x ≤ 0.35. The Te-rich limit of the 3R-TaSe_1.65Te_0.35 polytype shows the highest T_c in the system, 2.4 K, which is 17 times higher than that of 2H-TaSe₂. For 0.8 ≤ x ≤ 1.3, 1T-type TaSe_2−xTe_x emerges and shows a lower T_c, of 0.5–0.7 K. At higher Te substitutions (1.8 ≤ x ≤ 2), TaSe_2−xTe_x changes again, into the monoclinic polymorph, and shows normal metallic behavior to 0.4 K. We argue that the isovalent Te/Se substitution acts to tune the anisotropy of the layers, inducing the 3R to 1T transition, consistent with what has been proposed previously (25). The driving force for the 2H to 3R transition currently remains obscure.     

孕妇清火丸口服和肤舒止痒膏外洗治疗妊娠期肝内胆汁淤积症30例

目的:探讨口服孕妇清火丸和肤舒止痒膏外洗在妊娠期肝内胆汁淤积症治疗中的临床应用。方法:选取ICP患者60例,将其随机分为治疗组与对照组,每组30例。其中对照组给予思美泰静脉滴注治疗,治疗组给予口服孕妇清火丸和肤舒止痒膏外洗联合应用治疗,疗程为14 d。观察并比较两组患者瘙痒症状改善情况、孕周、肝功能指标的改善情况及妊娠结局等,并观察两组患者的不良反应。结果:两组患者治疗后,皮肤瘙痒症状出现明显好转,与治疗前比较,差异具有统计学意义(P<0.05);治疗后,治疗组患者瘙痒症状评分较对照组低,差异有统计学意义(P<0.05);治疗后,治疗组患者孕周为(37.1±0.12)周,与对照组患者(34.3±0.19)周比较,差异有统计学意义(P<0.05);治疗后,两组患者的总胆红素(TBIL)、丙氨酸氨基转移酶(ALT)及胆汁酸(TBA)水平都明显降低,与治疗前比较,差异有统计学意义(P<0.05);并且与对照组比较,治疗组治疗后TBIL、ALT及TBA水平下降更显著,有统计学意义(P<0.05);对照组在治疗过程中出现恶心、头痛、面色潮红等不良反应,而治疗组无不良反应发生。结论:口服孕妇清火丸和肤舒止痒膏外洗治疗妊娠期肝内胆汁淤积症具有明显的治疗效果,同时无明显的不良反应发生,值得在临床上大力的推广与应用。     

护患双方对经外周静脉的中心静脉置管带管出院患者健康教育认知差异性的调查

目的探讨护患双方在外周静脉的中心静脉置管(peripherally inserted central catheters,PICC)带管出院患者健康教育认知上的差异。方法便利抽样法选择2012年5-10月在上海某三级甲等医院PICC门诊维护患者50例和普外科、血液科、肿瘤科具有PICC维护证书的护士26名为研究对象。采用自行设计的问卷对其进行调查。结果 PICC带管出院患者主要为肘正中静脉置管,占42.0%。出现的不适状况主要以手臂肿胀为主,占30.0%。患者对PICC健康教育项目重要性认知与实际了解程度呈正相关(r=0.637,P0.05)。护士对PICC健康教育项目重要性认识与实际强调程度呈正相关(r=0.775,P0.05)。两者在PICC置管最重要的3项健康教育项目认知上有差异,患者注重自身生活、活动的影响及定时维护的要求,而护士更关注PICC穿刺处观察、导管维护、换药等方面。影响健康教育实施成效的原因,主要包括患者的年龄、文化程度、护士PICC相关知识、健康教育的认知和态度及护士工作的繁忙程度等。结论对PICC带管出院患者的健康教育要以患者的需求为出发点。     

胚胎中胚层间充质细胞参与小鼠胚胎原始心管的形成

目的 探讨小鼠胚胎早期原始心管发育. 方法 对胎龄7.5-9 d小鼠胚胎心脏进行石蜡连续切片,连续切片进行HE染色,并用抗转录因子GATA4和抗α-平滑肌肌动蛋白（α-SMA）抗体进行免疫组织化学染色. 结果 头端中胚层间充质细胞与小鼠胚胎原始心管及心包腔脏壁中胚层相延续;心肌早期分化标志蛋白转录因子GATA4和α-SMA在原始心管部位高表达. 结论 位于神经沟和原肠之间的胚胎中胚层间充质细胞参与原始心管和心包腔脏壁中胚层的形成;原始心管和心包腔脏壁中胚层细胞的迁移和分化机制不同.     

PDCA循环管理对提高老年干部病房护理服务质量的应用效果评价

目的探讨PDCA循环管理在提高老年干部病房护理服务质量中的应用效果。方法选取浙江省柯城区人民医院老年干部病房接受住院治疗的120例患者为研究对象,对比采用PDCA循环管理前后的护理人员对护理知识的掌握情况和患者对我科室护理满意情况。结果对比应用PDCA循环管理前、应用PDCA循环管理后护理人员护理理论知识得分由(72.38±8.21)分提高到(81.72±6.92)分,护理操作知识得分由(69.48±7.45)分提高到(86.32±5.71)分,患者对护理工作的满意度由41.67%提高到68.33%,差异具有统计学意义(P<0.05)。结论 PDCA循环管理能够有效提高老年干部病房护理服务质量,值得在临床上推广应用。