pH值测定在量化评价苏木精染液染色力中的初步应用

苏木精染液的染色力是影响HE染色成功的关键因素之一,而染色力随染色时间和切片数量的增加呈进行性下降.实际工作中技术人员大多依据个人经验来决定苏木精染液是否需要更换,缺乏统一标准,造成批间差异大.本文通过测定苏木精染液使用过程中pH值的变化来确定染液的酸度值,评价苏木精染液的染色力,为实际工作中苏木精染液的更换提供量化参考指标,从而更好地开展HE染色的质量控制.

生物基纤维PA56针织物的染色性能研究

生物基纤维PA56是由生物发酵制备的戊二胺和己二酸聚合而成的,PA56织物具有优异的服用性能。文中研究了弱酸性染料在PA56织物上的提升性能,探讨了染色体系的p H值、温度、染色时间对染色性能的影响,以及染色织物的色牢度性能。结果表明,与传统的PA66织物相比较,弱酸性染料在PA56织物上的上染速度较快;优化后染色工艺:溶液的p H值4.0~5.0,以1℃/min的升温速率升温至60℃,在该温度条件下保温染色30 min;用弱酸性染料染色的PA56织物耐摩擦色牢度良好,通过固色处理可以有效地改善耐洗色牢度。

“107”胶彩色水泥的配比

424104 湖南汝城县第二中学 叶晨雨 “107”胶彩色水泥具有良好的耐磨性,能在尚未干透的基层上施工,也可仿制木地板装饰纹理,且不会粉化、起砂,适于在水泥地板上刮抹。 “107”胶彩色水泥是以水溶性“107”胶为基料,与普通水泥和一定量的氧化铁系颜料组成的一种厚质涂料,但水泥标号不应低于425号,颜料应具有耐光性、耐碱性及染色力,如氧化铁红、氧化铁黄等。下面是几种常用色彩的配比:

“腈”读什么音?

我们在商场观光或购物过程中经常听到有人(包括售货员和顾客)把“腈”(京)错读成“晴”。如“给我看看那双晴纶袜！”等等。

Kinetochore dynein generates a poleward pulling force to facilitate congression and full chromosome alignment

For proper chromosome segregation, all kinetochores must achieve bipolar microtubule （MT） attachment and subsequently align at the spindle equator before anaphase onset. The MT minus end-directed motor dynein/dynactin binds kinetoehores in prometaphase and has long been implicated in chromosome congression. Unfortunately, inactivation of dynein usually disturbs spindle organization, thus hampering evaluation of its kinetochore roles. Here we specifically eliminated kinetochore dynein/dynactin by RNAi-mediated depletion of ZW10, a protein essential for kinetochore localization of the motor. Time-lapse microscopy indicated markedly-reduced congression efficiency, though congressing chromosomes displayed similar velocities as in control cells. Moreover, cells frequently failed to achieve full chromosome alignment, despite their normal spindles. Confocal microcopy revealed that the misaligned kinetochores were monooriented or unattached and mostly lying outside the spindle, suggesting a difficulty to capture MTs from the opposite pole. Kinetoehores on monoastral spindles were dispersed farther away from the pole and exhibited only mild oscillation. Furthermore, inactivating dynein by other means generated similar phenotypes. Therefore, kinetochore dynein produces on monooriented kinetochores a poleward pulling force, which may contribute to efficient bipolar attachment by facilitating their proper microtubule captures to promote congression as well as full chromosome alignment.

Cyclin B1 is localized to unattached kinetochores and contributes to efficient microtubule attachment and proper chromosome alignment during mitosis

Cyclin B1 is a key regulatory protein controlling cell cycle progression in vertebrates. Cyclin B1 binds CDK1, a cy-clin-dependent kinase catalytic subunit, forming a complex that orchestrates mitosis through phosphorylation of key proteins. Cyclin B1 regulates both the activation of CDK1 and its subcellular localization, which may be critical for substrate selection. Here, we demonstrate that cyclin B1 is concentrated on the outer plate of the kinetochore during prometaphase. This localization requires the cyclin box region of the protein. Cyclin B1 is displaced from individual kinetochores to the spindle poles by microtubule attachment to the kinetochores, and this displacement is dependent on the dynein/dynactin complex. Depletion of cyclin B1 by vector-based siRNA causes inefficient attachment between kinetochores and microtubules, and chromosome alignment defects, and delays the onset of anaphase. We conclude that cyclin B1 accumulates at kinetochores during prometaphase, where it contributes to the correct attachment of mi- crotubules to kinetochores and efficient alignment of the chromosomes, most likely through localized phosphorylation of specific substrates by cyclin B1-CDK1. Cyclin B1 is then transported from each kinetochore as microtubule attachment is completed, and this relocalization may redirect the activity of cyclin B1-CDK1 and contribute to inactivation of the spindle assembly checkpoint.

The adsorptive properties of UiO-66 towards organic dyes: A record adsorption capacity for the anionic dye Alizarin Red S.

In order to decisively determine the adsorption selectivity of zirconium MOF(UiO-66) towards anionic versus cationic species, the adsorptive removal of the anionic dyes(Alizarin Red S.(ARS), Eosin(E), Fuchsin Acid(FA)and Methyl Orange(MO)) and the cationic dyes(Neutral Red(NR), Fuchsin Basic(FB), Methylene Blue(MB),and Safranine T(ST)) has been evaluated. The results clearly reveal a significant selectivity towards anionic dyes. Such an observation agrees with a plethora of reports of UiO-66 superior affinity towards other anionic species(Floride, PO_4^(3-), Diclofenac sodium, Methylchlorophenoxy-propionic acid, Phenols, CrO_4^(2-), SeO_3^(2-), and AsO_4^-). The adsorption process of ARS as an example has been optimized using the central composite design(CCD). The resultant statistical model indicates a crucial effect of both pH and sorbent mass. The optimum conditions were determined to be initial dye concentration 11.82 mg.L^(-1), adsorbent amount 0.0248 g, shaking time of 36 min and pH 2. The adsorption process proceeds via pseudo-second order kinetics(R^2= 0.999). The equilibrium data were fit to Langmuir and Tempkin models(R^2= 0.999 and 0.997 respectively). The results reveal an exceptional removal for the anionic dye(Alizarin Red S.) with a record adsorption capacity of400 mg·g^(-1). The significantly high adsorption capacity of UiO-66 towards ARS adds further evidence to the recently reported exceptional performance of MOFs in pollutants removal from water.

Molecular Dynamics Simulation for the Effect of Chain Length of Spacer and Tail of Cationic Gemini Surfactant on the Complex with Anionic Polyelectrolyte

Interaction of anionic polyelectrolyte with cationic gemini surfactant has been investigated by coarse-grained molecular dynamics simulation.Polyelectrolyte facilitates the oppositely charged ionic surfactants to aggregate by suppressing the electrostatic repulsion between ionic head groups leading to the formation of micellar complex.With addition of surfactant,the conformation of polyion chain changes from stretched to random coiled to spherical,and at the same time more free micelles are formed by surfactants in mixtures.Increasing the length of spacer or tail chain in gemini surfactant will weaken its interaction with polyelectrolyte and simultaneously strengthen its tendency to self-assemble.The simulation results are consistent with experimental observations and reveal that the electrostatic interaction plays an important role in the interaction of polyelectrolyte with gemini sur- factant.

Visualization of chromatin folding patterns in chicken erythrocytes by atomic force microscopy (AFM)

The organization of the higher order structure of chromatin in chicken erythrocytes has been examined withtapping-mode scanning force microscopy under conditionsclose to their native environment. Reproducible highresolution AFM images of chromatin compaction at several levels can be demonstrated. An extended beads-on-astring (width of ～ 15-20nm, height of ～ 2-3nm for eachindividual nucleosome) can be consistently observed. Furthermore, superbeads (width of ～ 40nm, height of ～ 7nm)are demonstrated. Visualization of the solenoid conformation at the level of 30nm chromatin fiber is attained eitherby using AFM or by using electron microscopy. In addition, tightly coiled chromatin fibers (～ 50-60nm and ～90-110nm) can be revealed. Our data suggest that the chromatin in the interphase nucleus of chicken erythrocyte represents a high-order conformation and AFM provides useful high-resolution structural information concerning thefolding pattern of interphase chromatin fibers.

The structure of the nucleosome core particle of chromatin in chicken erythrocytes visualized by using atomicforce microscopy

The structure of the nuclosome core particle of chromatin in chicken erythrocytes has been examined by usingAFM. The 146 hp of DNA wrapped twice around the corehistone octamer are clearly visualized. Both the ends ofentry/exit of linker DNA are also demonstrated. The dimension of the nucleosome core particles is- 1-4 um inheight and ～13-22 um in width. In addition, superbeads(width of - 48-57 urn, beight of-2-3 nm) are occasionallyrevealed, two turns of DNA around the core particles arealso detected.

Complete Cytogenetic Insight of Tho-Tho Cattle

To investigate the cytogenetic parameters and characterise the chromosomal banding pattern of Tho-Tho cattle, a breed of indigenous cattle found in the Northeastern states of India were reared for meat purpose. Lymphocyte culture technique was carried out in 28 Tho-Tho cattle and culture was harvested for good metaphase spread. Good metaphase spreads were selected for analysis, such as relative length, centromeric index and arm ratio. Centromeric banding （C-banding） and reverse banding （R-banding） methods were done for detail and better understanding of the chromosome morphology. The chromosome number in Tho-Tho cattle was observed to be 2n = 60 in all complete metaphase. The mean relative length of the autosomal chromosomes varied from 5.48% ：~ 0.107% to 1.79% ＋ 0.105% in male and 5.31% ：E 0.148% to 1.86% ＋ 0.055% in female, respectively. The chromosome banding showed C-positive dark band heterochromatin in all the acrocentric autosome. However, in sex chromosome, the Y-chromosome showed negative C-band and also the X-chromosome did not show any stain at the centromeric region. The numbers of R-band pattern were observed to be 490 and 499 band in male and female, respectively. One of the X-chromosome showed light banding pattern, confirming the inactivation during the embryonic development in female. The fundamental chromosome number and banding pattern of Tho-Tho cattle did not vary from the other breed of the Bos indicus. However, it is necessary to start a cytogenetic screening of the Tho-Tho cattle and expand upon more number to be kept at different villages of Nagaland in order to identify animals with chromosomal abnormalities, so that it can be excluded from future breeding strategies for conservation of Tho-Tho genetic resource.

Bio-reduction of Sulphur Dyes with Alkaline Pectinase

Sulphur dyes are invariably applied on cotton to produce deep shades at cheaper cost possessing all-round fastness properties except against chlorine. Being water insoluble, these dyes are reduced and solubilised with sodium sulphide at boil to develop affinity for cotton. Application of sulphide has generated global debate because of its eco-unfriendly technology of dyeing. In this work, attempts were made to substitute sodium sulphide with alkaline pectinase. Obtained results suggested the ability of the latter to cause effective reduction and solubilisation of sulphur dyes. Stability of reduction baths as well as colour fastness was also reported to be in line with those obtained using sodium sulphide.

Biodegradation of Acid Anthraquinone Dye in a Facultative-aerobic Process:Kinetics and Products

The transformation of an anthraquinone dye blue 324 in a facultative-aerobic(F-A) system was investigated.Kinetic parameter study showed that higher Vmax coupled with more recalcitrant chemical oxygen demand(COD) were found in the facultative biofilm reactor(FBR) than in the aerobic reactor(AR).Results of the product analyses indicated that most of dye molecular could be facultatively broken down into simple intermediates,which would be further degraded under subsequent aerobic condition.The main metabolites in each reactor were detected by infrared(FT-IR) and high performance liquid chromatography and mass spectrometry(HPLC-MS).Comparison of the toxicities among the dye and its metabolites was conducted,surprisingly,the colorless intermediates from FBR possessed less inhibitory than original dye and the median effective luminescence concentration(EC50) in 15 min for aerobic effluent could not be detected,showing that hardly toxic products existed in the aerobic process effluent.

The Comparison of Amaranth Decolorization Ability for Two Types of Biological Consortia

The two types of biological consortia--real activated sludge and laboratory adapted consortium were immobilized in polyethylene oxide cryogels. Their potential to decolorize the anionic azo dye amaranth in sequencing batch biofilters was studied. At a growing concentration of azo dye （20 mg·L^-1, 25 mg·L^-1, 30 mg·L^-1） the biofilters had a mean feeding rate of 30.32 ± 25.78 mL^-1·h^-1 and 13.76 ：t： 8.33 mL^-1·h^-1, respectively for immobilized adapted consortia （AC） and activated sludge （AS）. The AC-biofilter reached an overall decolorization rate of 0.211 ± 0.14 mg dye.mLLh1 and a decolorization effectiveness of 60.28 ：t： 32.42%. In contrast, the mean values for overall decolorization rate and effectiveness in AS-biofilter were 0.249 ± 0.16 mg dye.mL^-1·h^-1 and 82.48± 14.41%. The system with immobilized activated sludge had more stable process dynamics and higher tolerance to shock azo dye loading in the first stage of the process. The immobilized adapted consortium presented a good ability to adequate response at higher azo dye concentrations and loading.

黑色缓蚀阻垢剂

本发明公开一种黑色缓蚀阻垢剂，是由胡敏酸钠、水溶性硫化元按比例混合搅拌均匀制成，也可加入亚甲基二萘磺酸钠、钠盐和防灰剂。利用硝敏酸钠和水溶性硫化元的缓蚀阻垢特性及对于水的极强染色力，产品水溶性好，扩散迅速，无毒无味，即使发生饮用，也不会造成中毒现象，成本低廉，使用简单，同时具有防止供热管路结垢的作用。

绘画材料与技法（二）

绘画材料与技法（二）刘永奎颜料颜料是物质实体，天然的颜料是从动物或植物中提取的，如茜（草）红、胭脂红等。人工制造的颜料是从煤焦油、沥青中提取的，如硫靛蓝、深红等，用有机物质烧制而成的黑色如象牙黑、葡萄黑等，这些都是有机颜料。从自然的矿物质原料中提取的...

Inhibition of BET selectively eliminates undifferentiated pluripotent stem cells

Embryonic stem cells （ESCs） maintain their cellular identity through the systematic regulation of master transcription factors and chromatin remodeling complexes. Recent work has shown that the unusually large-scale enhancers-namely super-enhancers （SEs）, on which BRD4, a member of the bromodomain and extraterminal domain （BET） family is highly enriched-could regulate pluripotency-related transcrip- tion factors. Moreover, inhibition of BRD4 binding on SEs has been shown to induce the differentiation of ESCs. However, the underlying mechanism of BRD4 inhibition-mediated stern cell differentiation remains elusive. Here we show that both mouse and human ESCs lose their capacity for self-renewal upon treat- ment with JQ1, a selective inhibitor of BET family including BRD4, with rapid suppression of pluripotency-associated genes. Notably, a high concentration of JQI could selectively eliminate ESCs via apoptosis, without affecting the functionality of differentiated somatic cells from ESCs, suggesting that inhibition of BET may have a beneficial effect on the development of pluripotent stem cell-based cell therapy.

Regulation of sister chromatid cohesion during the mitotic cell cycle

Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chromatids during DNA replication in a process termed sister chromatid cohesion. Timely establishment and dissolution of sister chromatid cohesion is a prerequisite for accurate chromosome segregation, and is tight regulated by the cell cycle machinery and cohesin-associated proteins. In this review, we discuss recent progress in the molecular understanding of sister chromatid cohesion during the mitotic cell cycle.

Mitosis-specific acetylation tunes Ran effector binding for chromosome segregation

Stable transmission of genetic information during cell division requires faithful mitotic spindle assembly and chromosome segregation. The Ran GTPase plays a key role in mitotic spindle assembly. However, how the generation of a chemical gradient of Ran-GTP at the spindle is coupled to mitotic post-translational modifications has never been characterized. Here, we solved the complex structure of Ran with the nucleotide release factor Mogl and delineated a novel mitosis-specific acetylation-regulated Ran-Mogl interaction dur- ing chromosome segregation. Our structure-guided functional analyses revealed that Mogl compotes with RCCl for Ran binding in a GTP/GDP-dependent manner. Biochemical characterization demonstrated that Mogl-bound Ran prevents RCCl binding and subse- quent GTP loading. Surprisingly, Ran is a bono fide substrate of TIP60, and the acetylation of Lys134 by TIP60 liberates Mogl from Ran binding during mitosis. Importantly, this acetylation-elicited switch of Ran binding to RCC1 promotes high level of Ran-GTP, which is essential for chromosome alignment. These results establish a previously uncharacterized regulatory mechanism in which TIP60 pro- vides a homeostatic control of Ran-GTP level by tuning Ran effector binding for chromosome segregation in mitosis.