Osmunda (Osmundaceae) from the Triassic of Antarctica: an example of evolutionary stasis

Compressed specimens of the fern Osmunda are described from the Triassic of the Allan Hills, Antarctica. The specimens consist of a once pinnate, deeply pinnatifid fertile frond as well as several sterile specimens. Six pinnae are present on the partial fertile rachis, with two sterile pinnae above four fertile pinnae. Both sterile and fertile specimens are virtually identical to the modern species Osmunda claytoniana. Entire fronds are fragmentary; the longest is 21 cm in length. Sterile pinnae are alternate and deeply pinnatifid, with slightly toothed pinnules and dichotomous venation. Fertile pinnae are 1-1.3 cm long, once pinnate, and lack vegetative lamina. Sporangia are clustered, each 300-375 um in diameter, and possess a transverse annulus 6-8 cells long; dehiscence is by a vertical slit. Fronds arise from a rhizome 4 cm long by 1 cm wide; two croziers are present on the rhizome. Two frond segments up to 6 cm long and three deeply pinnatifid pinnae are present on the uppermost part of one rachis. Pinnules are ~4 mm long and 2-3 mm wide. The presence of this Osmunda species in the Triassic demonstrates stasis of frond morphology, both fertile and vegetative, for the genus.     

不同粘度骨水泥椎体成形术对骨质疏松椎体压缩性骨折的临床疗效及生活质量的影响

目的:比较不同粘度骨水泥椎体成形术(PVP)治疗骨质疏松椎体压缩性骨折(OVCF)的临床疗效及生活质量的影响。方法:回顾性分析于2016年8月至2018年2月期间我院收治的104例OVCF患者的临床资料。将患者按数字表法分为对照组(n=52)和研究组(n=52),两组患者均给予PVP治疗,对照组选用低粘度骨水泥,研究组选用高粘度骨水泥。比较两组患者术前、术后1周、术后1个月、术后3个月、术后6个月及术后12个月的Oswestry功能障碍指数(ODI)评分、疼痛视觉模拟量表(VAS)评分、健康状况调查问卷(SF-36)评分以及Cobb角,记录两组并发症发生情况。结果:研究组患者手术时间长于对照组(P<0.05),而两组患者骨水泥注入量、住院时间比较差异无统计学意义(P>0.05)。两组患者术后1周、1个月、3个月、6个月、12个月ODI评分、VAS评分、Cobb角均较术前降低(P<0.05);两组患者术后1个月、3个月、6个月、12个月ODI评分、VAS评分、Cobb角均较术后1周降低(P<0.05);研究组术后1周、1个月、3个月、6个月、12个月ODI评分、VAS评分、Cobb角低于对照组(P<0.05)。两组患者术后1周、1个月、3个月、6个月、12个月SF-36评分均升高,且研究组高于对照组(P<0.05)。两组并发症发生率比较无统计学差异(P>0.05)。结论:高粘度骨水泥应用于PVP治疗OVCF患者疗效确切,可有效减轻患者疼痛状况,改善生活质量,促进患者恢复。     

掌侧入路、背侧入路微创加压螺钉固定术治疗腕舟骨骨折的疗效比较及对血清创伤应激指标和疼痛介质的影响

摘要 目的：比较掌侧入路、背侧入路微创加压螺钉固定术治疗腕舟骨骨折的疗效,以及分别对血清创伤应激指标和疼痛介质的影响。方法：本研究为回顾性研究,临床资料来源于2018年1月~2021年1月来我院接受治疗的88例腕舟骨骨折患者,根据入路方式的不同分为A组（背侧入路,43例）和B组（掌侧入路,45例）。观察两组患者腕功能优良率、围术期相关指标、视觉疼痛模拟评分（VAS）、腕关节活动度、血清创伤应激指标、疼痛介质情况。结果：两组优良率组间对比未见明显差异（P>0.05）。B组术中出血量少于A组,骨性愈合时间短于A组（P<0.05）,两组手术时间对比无差异（P>0.05）。B组术后6个月VAS评分低于A组（P<0.05）。两组术后1年腕关节掌屈、背伸、桡偏、尺偏活动度均增大（P<0.05）。两组术后3 d皮质醇（Cor）、C反应蛋白（CRP）、促肾上腺皮质激素（ACTH）均升高,但B组低于A组（P<0.05）。两组术后3 d、前列腺素E₂（PGE₂）、P 物质（SP）、β-内啡肽（β-EP）均下降,且B组低于A组（P<0.05）。结论：掌侧入路、背侧入路微创加压螺钉固定术治疗腕舟骨骨折,疗效相当,其中掌侧入路可减少术中出血量,促进骨折愈合,同时还可减轻术后疼痛、术后创伤,综合疗效相对更好。     

Geotechnical Aspects of Oil-Contaminated Sands

Contamination due to chemicals and oil spills can influence the engineering behavior of soils. The results of an investigation conducted to study the effects of oil contamination on compaction characteristics, shear strength, one-dimensional compression, and hydraulic conductivity of a sand are presented in this article. The test results indicate that the compaction characteristics are influenced by oil contamination. The angle of internal friction of sand based on total stress condition was found to decrease with the presence of oil in the pore spaces. One-dimensional compression characteristics of sand are significantly influenced by oil contamination, resulting in a decrease in the value of the constrained modulus with increase in the degree of oil saturation. Hydraulic conductivity was observed to be a function of the initial viscosity and the degree of oil saturation.     

太鼠坐骨神经、胫神经、腓总神经在脊髓胶状质定位投射的定量分析—FRAP 法

本实验按照跨神经节溃变的原理,用抗氟化物酸性磷酸酶(FRAP)法和显微测量,对大鼠坐骨神经,胫神经和腓总神经感觉纤维在脊髓胶状质的定位投射进行了定量分析。大鼠坐骨神经和胫神经向胶状质的纵向投射为 L_(2～3);腓总神经为 L_(2.6)及 S_1的上中部。水平向投射,坐骨神经:L_(2～3)主要为胶状质的最内侧和中间区的部分区域,L_4～S_1,主要为内侧,中间和部分外侧区的全部胶状质,但未见向胶状质最外侧区投射;胫神经:L_2～S_1主要为内侧区,中间及部分外侧区仅部分实验动物有投射;腓总神经:仅向 L_2～S_1的中间和部分外侧区一处投射。     

Effect of polysulfonate resins and direct compression fillers on multiple-unit sustained-release dextromethorphan resinate tablets

The purpose of this work was to investigate the effect of different polysulfonate resins and direct compression fillers on physical properties of multiple-unit sustained-release dextromethorphan (DMP) tablets. DMP resinates were formed by a complexation of DMP and strong cation exchange resins, Dowex 50 W and Amberlite IRP69. The tablets consisted of the DMP resinates and direct compression fillers, such as microcrystalline cellulose (MCC), dicalcium phosphate dihydrate (DCP), and spray-dried rice starch (SDRS). Physical properties of tablets, such as hardness, disintegration time, and in vitro release, were investigated. A good performance of the tablets was obtained when MCC or SDRS was used. The use of rod-like and plate-like particles of Amberlite IRP69 caused a statistical decrease in tablet hardness, whereas good tablet hardness was obtained when spherical particle of Dowex 50 W was used. The plastic deformation of the fillers, such as MCC and SDRS, caused a little change in the release of DMP. A higher release rate constant was found in the tablets containing DCP and Dowex 50 W, indicating the fracture of the resinates under compression, which was attributable to the fragmentation of DCP. However, the release of DMP from the tablets using Amberlite IRP69 was not significantly changed because of the higher degree of cross-linking of the resinates, which exhibited more resistance to deformation under compression. In conclusion, the properties of polysulfonate resin, such as particle shape and degree of cross-linking, and the deformation under compaction of fillers affect the physical properties and the drug release of the resinate tablets. Published: September 30, 2005.     

Pretransition and progressive softening of bovine carbonic anhydrase II as probed by single molecule atomic force microscopy

To develop a simple method for probing the physical state of surface adsorbed proteins, we adopted the force curve mode of an atomic force microscope (AFM) to extract information on the mechanical properties of surface immobilized bovine carbonic anhydrase II under native conditions and in the course of guanidinium chloride-induced denaturation. A progressive increase in the population of individually softened molecules was probed under mildly to fully denaturing conditions. The use of the approach regime of force curves gave information regarding the height and rigidity of the molecule under compressive stress, whereas use of the retracting regime of the curves gave information about the tensile characteristics of the protein. The results showed that protein molecules at the beginning of the transition region possessed slightly more flattened and significantly more softened conformations compared with that of native molecules, but were still not fully denatured, in agreement with results based on solution studies. Thus the force curve mode of an AFM was shown to be sensitive enough to provide information concerning the different physical states of single molecules of globular proteins.     

Feulgen-positive staining of the cell nuclei in fossilized leaf and fruit tissues of the Lower Eocene Myrtaceae

The Feulgen reaction and the staining of preparations with two DNA-specific fluorochromes, Hoechst 33258 and 4',6-diamidino-2-fenilindol (DAPI), were used to study the preservation of DNA in the fossilized leaf and fruit tissues of the Lower Eocene Myrtaceae, Paramyrtacicarpus plurilocularis and Paramyrtaciphyllum agapovii collected in Yakutia (Siberia, Russia). It was shown that chromatin structures of the fossilized plants form stable red-purple complexes with the Schiff's fuchsin sulphuric acid reagent in situ . This coloration is specific for DNA, in particular, for the deoxyribose residues. It means that the cell nuclei of these 53–55 Myr old plants preserve a part of the deoxyribose backbone of DNA molecules. On the other hand, there was no, or only a very weak, staining of the cell nucleus with fluorochromes DAPI or Hoechst 33258, which specifically bind to the double-stranded DNA and do not bind to either the single-stranded DNA or RNA molecules. The stainability of fossil plant cell preparations with alcian blue shows that there are also polysaccharides containing carboxyl groups in the cell walls of fossilized leaf and fruit tissues of the Lower Eocene Myrtaceae.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 315–321.     

微血管减压与经皮穿刺球囊压迫治疗原发性三叉神经痛的临床观察

目的:对比微血管减压(MVD)和经皮穿刺球囊压迫(PBC)治疗原发性三叉神经痛(PTN)的疗效。方法:选择2010年5月至2013年11月在我院接受治疗的PTN患者124例进行研究,根据数字法随机分成MVD组及PBC组各62例,两组分别行对应手术,随访18个月,对比两组手术相关指标、疗效以及术后并发症。结果:MVD组的手术时间与术中出血量,以及住院时间和住院费用均分别大于PBC组(均P0.05)。MVD组治疗后完全无痛的比例显著高于PBC组,轻度复发的比例显著低于PBC组(均P0.05)。MVD组的麻木及总并发症发生率均分别显著低于PBC组(均P0.05)。结论:MVD术式与PBC术式在治疗PTN时均具有较好的疗效,MVD术后无痛和并发症情况较好,而PBC创伤较小,较适合高龄体弱而无法耐受较大手术者,临床治疗时应合理地选用相关术式。