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71.

Purpose

To compare the outcomes of femtosecond laser-assisted cataract surgery (FLACS) with those of conventional phacoemulsification surgery (CPS) for age-related cataracts.

Methods

A comprehensive literature search of PubMed, EMBASE, and the Cochrane Controlled Trials Register was conducted to identify randomized controlled trials (RCT) and comparative cohort studies comparing FLACS with CPS. Endothelial cell loss percentage (ECL%), central corneal thickness (CCT), corrected and uncorrected distant visual acuity (CDVA and UDVA), and mean absolute error (MAE) of refraction were used as primary outcomes. Secondary outcomes included surgically induced astigmatism (SIA), mean effective phacoemulsification time (EPT), phacoemulsification power and circularity of the capsulorhexis.

Results

Nine RCTs and fifteen cohort studies including 4,903 eyes (2,861 in the FLACS group and 2,072 in the CPS group) were identified. There were significant differences between the two groups in ECL% at one week, about one month and three months postoperatively, in CCT at one day, about one month postoperatively and at the final follow-up, in CDVA at one week postoperatively, and in UDVA at the final follow-up. Significant differences were also observed in MAE, EPT, phacoemulsification power, and the circularity of capsulorhexis. However, no significant differences were observed in CDVA at one week postoperatively or in surgically induced astigmatism.

Conclusions

Compared to CPS, FLACS is a safer and more effective method for reducing endothelial cell loss and postoperative central corneal thickening as well as achieving better and faster visual rehabilitation and refractive outcomes. However, there is no difference in final CDVA and surgically induced astigmatism between the two groups.  相似文献   
72.
草鱼出血病病毒的RNA转录酶活性研究   总被引:6,自引:1,他引:6  
黄健  柯丽华 《病毒学报》1992,8(1):50-56
  相似文献   
73.
黑龙江省一株红小豆锈病病原菌鉴定   总被引:2,自引:0,他引:2  
【目的】为明确发生在黑龙江省大庆市红小豆田中的锈病病原物的分类地位。【方法】从大庆市采集红小豆锈病标样,采用单孢子堆分离法获得一株红小豆锈病菌纯培养物ZXL01。采用观测夏孢子芽孔数目、位置和冬孢子壁厚度等形态学特征结合ITS序列分析的方法,对其进行鉴定。【结果】ZXL01夏孢子发芽孔多为2个,位于孢子赤道部位较远之处,冬孢子壁厚度为2.9μm-3.3μm。在基于r DNA-ITS序列构建的系统发育树中,ZXL01菌株与两株豇豆单胞锈菌(Uromyces vignae)的参比菌株(Gen Bank登录号:AB115718和AB115731)在自举值99%相聚一群。用豇豆单胞锈菌的特异性引物UV-ITSF/R进行检测,ZXL01菌株可扩增出500 bp左右的特征片段。【结论】黑龙江省大庆市红小豆锈病病原菌ZXL01菌株为豇豆单胞锈菌,ZXL01菌株的Gen Bank登录号是KM461700。  相似文献   
74.
Summary Plant regeneration in Kentucky bluegrass (Poa pratensis L. cv. Touchdown) via culture of seedling tissues was investigated. When coleoptile, leaf, and stem sections of dark-germinated seedlings were cultured on Murashige and Skoog (MS) medium, different types of callus were produced, depending on the expiant source and growth regulator combinations. Only compact-friable callus (type 3) and moderately compact, friable callus (type 2) produced shoots upon subculture. The nonstructured watery callus (type 4) produced roots without shoots. Shoot differentiation from callus tissues was highest when the culture medium contained 0.2 mgL–1 picloram + 0.01 mgL–1 -naphthaleneacetic acid (NAA). Calli grown from coleoptiles had higher shoot regeneration frequency (32%) than that obtained from either stem sections (12%) or young leaf tissues (2%) of the same seedlings. Some organogenic callus lines produced exclusively green plants, while others produced albino shoots or a mixture of green and albino shoots. The green plants were multiplied in a medium containing 0.1 mgL–1 BAP plus either 0.2 mgL–1 picloram or 0.1 mgL–1 indole-3-acetic acid (IAA). Over 90% of the cultures in the shoot proliferation medium produced roots in 4 weeks. The rooted plants were successfully established in soil medium and grown in the greenhouse.Abbreviations BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indole-3-acetic acid - MS Murashige and Skoog (1962) medium - NAA -naphthaleneacetic acid - picloram 4-amino-3,5,6-trichloropicolinic acid - TDZ thidiazuron  相似文献   
75.
植物通过每隔几年产生大量种子的丰年策略提高贮食动物传播种子效率,但人为采摘活动降低了种子的可利用量,从而影响贮食动物行为及种群动态。为研究红松球果采摘如何通过降低松果可利用量而影响贮食动物行为,我们基于黑龙江凉水自然保护区2003-2012年红松结实量和采摘量的变化,比较分析了结实大小年间松鼠贮点大小、贮点深度、贮食密度和贮藏量、松鼠花鼠种群以及2010年和2011年花鼠洞穴贮藏量的差异。结果显示:结实大年松鼠的平均贮点大小显著高于小年,大贮点比例增加,贮食密度和贮藏量也明显高于结实小年,但随着结实量的增大,球果采摘量增加,使松果可利用量减少,由此结实大年2011年松鼠贮食密度并未随结实量增加而增加,反而低于2003年和2008年,松鼠遇见率也没有在该结实大年有所增长。而花鼠种群和洞穴松籽贮藏量在结实大年和小年间没有显著差异。研究表明红松球果采摘对松果可利用量和松鼠贮食行为有较大影响,应合理确定大年的采摘量以保证贮食动物的食物丰度,维系红松生态系统健康。  相似文献   
76.
77.
78.
CircPRTM5 is associated with cell proliferation and migration in many kinds of malignancies. However, the functions and mechanisms of CircPRTM5 in CRC progression remain unclear. We explored the role and the mechanisms of CircPRTM5 in the development of CRC. Tissues of CRC patients and matched adjacent non-tumour tissues were collected to evaluate the expression of CircPRTM5. The expression of CircPRTM5 in CRC tissues was significantly higher than that in adjacent tissues. The biological functions of CircPRTM5 in CRC were determined by overexpression and down-regulation of CircPRTM5 in CRC cells in vitro and in vivo. The results indicate that knockdown of CircPRTM5 can significantly inhibit the proliferation of CRC cells. The potential mechanisms of CircPRTM5 in CRC development were identified by RT-qPCR, Western blotting analysis and luciferase reporter assay. CircPRTM5 competitively regulates the expression of E2F3 by capillary adsorption of miR-377. CircPRMT5 regulates CRC proliferation by regulating the expression of E2F3, which affects the expression of the cell cycle-associated proteins cyclinD1 and CDK2. CircPRTM5 exerts critical regulatory role in CRC progression by sponging miR-377 to induce E2F3 expression.  相似文献   
79.
80.

Background

Shape complementarity and non-covalent interactions are believed to drive protein-ligand interaction. To date protein-protein, protein-DNA, and protein-RNA interactions were systematically investigated, which is in contrast to interactions with small ligands. We investigate the role of covalent and non-covalent bonds in protein-small ligand interactions using a comprehensive dataset of 2,320 complexes.

Methodology and Principal Findings

We show that protein-ligand interactions are governed by different forces for different ligand types, i.e., protein-organic compound interactions are governed by hydrogen bonds, van der Waals contacts, and covalent bonds; protein-metal ion interactions are dominated by electrostatic force and coordination bonds; protein-anion interactions are established with electrostatic force, hydrogen bonds, and van der Waals contacts; and protein-inorganic cluster interactions are driven by coordination bonds. We extracted several frequently occurring atomic-level patterns concerning these interactions. For instance, 73% of investigated covalent bonds were summarized with just three patterns in which bonds are formed between thiol of Cys and carbon or sulfur atoms of ligands, and nitrogen of Lys and carbon of ligands. Similar patterns were found for the coordination bonds. Hydrogen bonds occur in 67% of protein-organic compound complexes and 66% of them are formed between NH- group of protein residues and oxygen atom of ligands. We quantify relative abundance of specific interaction types and discuss their characteristic features. The extracted protein-organic compound patterns are shown to complement and improve a geometric approach for prediction of binding sites.

Conclusions and Significance

We show that for a given type (group) of ligands and type of the interaction force, majority of protein-ligand interactions are repetitive and could be summarized with several simple atomic-level patterns. We summarize and analyze 10 frequently occurring interaction patterns that cover 56% of all considered complexes and we show a practical application for the patterns that concerns interactions with organic compounds.  相似文献   
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