• 【断裂修复后跟腱延长:两种术后方案的随机比较。】 复制标题 收藏 收藏
    DOI:10.1177/0363546506293255 复制DOI
    作者列表:Kangas J,Pajala A,Ohtonen P,Leppilahti J
    BACKGROUND & AIMS: BACKGROUND:A few prospective controlled trials comparing early functional rehabilitation after Achilles tendon repair and non-operative immobilization have been reported. HYPOTHESES:There is no difference in Achilles tendon elongation between early motion and immobilization after Achilles tendon repair. Tendon elongation does not correlate with the clinical outcome. STUDY DESIGN:Randomized clinical trial; Level of evidence, 2. METHODS:Fifty patients with acute Achilles tendon rupture were randomized postoperatively to receive either early movement of the ankle between neutral and plantar flexion in a brace for 6 weeks or immobilization in tension using a below-knee cast with the ankle in a neutral position for 6 weeks. Full weightbearing was allowed after 3 weeks in both groups. Standardized radiographs to measure previously placed radiographic markers were taken on the first day postoperatively and at 1, 3, 6, 12, 24 weeks postoperatively, with the final radiograph a mean of 60 (SD, 6.4) weeks postoperatively. The outcome was assessed at the 3-month and final checkups by the clinical scoring method described by Leppilahti et al and included subjective factors and objective factors. RESULTS:Tendon elongation occurred in both groups but was somewhat less in the early motion group (median 2 mm in the early motion group vs median 5 mm in the cast group a mean of 60 weeks postoperatively, P = .054). The elongation curves first rose and then slowly fell in both groups. The patients who had less elongation achieved a better clinical outcome (rho = -.42, P = .017). Tendon elongation did not correlate significantly with age, body mass index, or isokinetic peak torques. CONCLUSION:Achilles tendon elongation was somewhat less in the early motion group and correlated with the clinical outcome scores. We recommend early functional postoperative treatment after Achilles rupture repair.
    背景与目标: 背景:一些前瞻性对照试验比较了跟腱修复和非手术固定后的早期功能康复。
    假设:跟腱修复后的早期运动与固定之间的跟腱伸长没有差异。肌腱伸长与临床结果无关。
    研究设计:随机临床试验;证据水平2。
    方法:将50例急性跟腱断裂患者术后随机接受踝关节在中性和足底屈曲之间的早期运动,持续6周,或使用膝下石膏将踝关节置于中性位置,以固定不动的张力,持续6周。周。两组均在3周后允许完全负重。术后第一天和术后1、3、6、12、24周拍摄标准化的X线照片以测量先前放置的X线标记,最后的X射线照片平均在术后60(SD,6.4)周。结果通过Leppilahti等人描述的临床评分方法在3个月及最终体检时进行评估,其中包括主观因素和客观因素。
    结果:两组的肌腱伸长均发生,但早期运动组则有所减少(早期运动组中位2 mm,而石膏组中位5 mm,平均术后60周,P = .054)。两组的伸长率曲线先上升,然后缓慢下降。伸长率较低的患者获得较好的临床预后(rho = -.42,P = .017)。肌腱伸长率与年龄,体重指数或等速运动峰值扭矩无显着相关性。
    结论:早期运动组跟腱伸长率略低,且与临床结果评分相关。我们建议跟腱断裂修复后尽早进行术后功能治疗。
  • 【通过自发性破裂进入胆道来解决hy虫肝囊肿。】 复制标题 收藏 收藏
    DOI:10.1016/s0168-8278(97)80479-5 复制DOI
    作者列表:Becker K,Frieling T,Saleh A,Häussinger D
    BACKGROUND & AIMS: Among the complications of hydatid liver disease, spontaneous cyst rupture into the biliary tract is unusual, occurring in 3.2-17% of cases. Its endoscopic management has been reported rarely, and corresponding complete photodocumentation is unique. Such a case is described and comprehensively illustrated in a 48-year-old immunocompromised man, presenting with upper abdominal pain, obstructive jaundice, and fever. Impaction of hydatid material into the common bile duct and the papilla of Vater was relieved endoscopically, and the patient was consecutively treated with two courses of mebendazole. This management resulted in complete clinical resolution of hepatic hydatosis after 8 months of follow-up. Complications of overt cyst perforation may be allergic, obstructive, secondary infectious, or metastatic. Ultrasound and computed tomography are complementary tools for diagnosis of hepatic echinococcosis, with endoscopic retrograde cholangiography being the "gold standard" in confirming rupture into the biliary system. Laboratory results are usually non-specific. While surgical excision is the treatment of choice, selected patients may primarily be managed endoscopically, followed by anthelminthic therapy.

    背景与目标: 在包虫性肝病的并发症中,自发性囊肿破裂进入胆道是罕见的,发生在3.2-17%的病例中。对其内窥镜治疗的报道很少,并且相应的完整照片记录也很独特。此类病例在一名48岁免疫力低下的男性患者中得到描述和全面说明,其表现为上腹痛,阻塞性黄疸和发烧。内窥镜下观察到hy虫物质对胆总管和Vater乳头的影响,并连续用了两疗程的甲苯咪唑治疗该患者。随访8个月后,这种处理导致了肝脏水肿的完全临床解决。明显的囊肿穿孔的并发症可能是过敏性,阻塞性,继发性感染或转移性的。超声和计算机断层扫描是诊断肝棘球菌病的辅助工具,内镜逆行胆管造影术是确认胆道系统破裂的“金标准”。实验室结果通常是非特异性的。尽管选择手术切除是一种治疗方法,但是可以对某些患者进行内镜治疗,然后再进行驱虫治疗。

  • 【模拟牙髓压力对与牙本质的多合一粘合剂粘结强度的影响。】 复制标题 收藏 收藏
    DOI:10.1016/j.jdent.2006.08.001 复制DOI
    作者列表:Hosaka K,Nakajima M,Yamauti M,Aksornmuang J,Ikeda M,Foxton RM,Pashley DH,Tagami J
    BACKGROUND & AIMS: OBJECTIVES:To evaluate the durability of all-in-one adhesive systems bonded to dentine with and without simulated hydrostatic pulpal pressure (PP). METHODS:Flat dentine surfaces of extracted human molars were prepared. Two all-in-one adhesive systems, One-Up Bond F (OBF) (Tokuyama Corp., Tokyo, Japan), and Fluoro Bond Shake One (FBS) (Shofu Co., Kyoto, Japan) were applied to the dentine surfaces under either a PP of 0 or 15cm H(2)O. Then, resin composite build-ups were made. The specimens bonded under pressure were stored in 37 degrees C water for 24h, 1 and 3 months under 15cm H(2)O PP. Specimens not bonded under pressure were stored under zero PP. After storage, the specimens were sectioned into slabs that were trimmed to hourglass shapes and subjected to micro-tensile bond testing (muTBS). The data were analysed using two-way ANOVA and Holm-Sidak HSD multiple comparison tests (alpha=0.05). RESULTS:The muTBS of OBF fell significantly (p<0.05) when PP was applied during bonding and storage, regardless of storage time. In contrast, although the muTBS of OBF specimens bonded and stored without hydrostatic pressure storage fell significantly over the 3 months period, the decrease was less than half as much as specimens stored under PP. In FBS bonded specimens, although there was no significant difference between the muTBS with and without hydrostatic pulpal pressure at 24h, by 1 and 3 months of storage under PP, significant reductions were seen compared with the control group without PP. CONCLUSION:The muTBS of OBF bonded specimens was lowered more by simulated PP than by storage time; specimens bonded with FBS were not sensitive to storage time in the absence of PP, but showed lower bond strengths at 1 and 3 months in the presence of PP.
    背景与目标: 目的:评估在有和没有模拟静水牙髓压(PP)的情况下粘合到牙本质的多合一粘合剂体系的耐久性。
    方法:制备人牙磨牙的平面牙本质表面。在牙本质表面上使用了两种多合一粘合剂系统,即One-up Bond F(OBF)(日本东京Tokuyama公司)和Fluoro Bond Shake One(FBS)(日本京都Shofu Co.)。在0或15cm H(2)O的PP下。然后,制成树脂复合材料。在压力下粘合的样品在15cm H(2)O PP下于37摄氏度的水中存储24h,1和3个月。未在压力下粘合的样品存储在零PP下。储存后,将标本切成薄片,将其修整为沙漏形状,并进行微拉伸粘合力测试(muTBS)。使用双向方差分析和Holm-Sidak HSD多重比较测试(α= 0.05)分析数据。
    结果:在粘结和储存过程中,无论储存时间如何,使用PP时,OBF的muTBS均显着下降(p <0.05)。相比之下,虽然在没有静水压力存储的情况下粘合和存储的OBF标本的muTBS在3个月内显着下降,但下降幅度不到在PP下存储的标本的一半。在FBS粘结的标本中,尽管在24h下有和没有静水纸浆压力的muTBS之间没有显着差异,但在PP下储存1和3个月时,与未使用PP的对照组相比,观察到显着降低。
    结论:模拟PP降低了OBF粘结样品的muTBS,而不是保存时间降低了。在没有PP的情况下,用FBS粘结的样品对储存时间不敏感,但是在有PP的情况下,在1个月和3个月时,其粘结强度较低。
  • 【气态臭氧和ND:YAG激光的应用对玻璃纤维后结合强度的影响。】 复制标题 收藏 收藏
    DOI:10.1111/j.1747-4477.2010.00265.x 复制DOI
    作者列表:Kıvanç BH,Arısu HD,Ozcan S,Görgül G,Alaçam T
    BACKGROUND & AIMS: :The aim of this study was to investigate the effects of the application of gaseous ozone and Nd:YAG laser on glass-fibre post bond strength. Forty-two madibular premolar roots were cut, endodontically instrumented and irrigated with 2.5% NaOCl. Post spaces were prepared and roots were divided into three groups (n = 14). The antimicrobial pretreatment was conducted as follows: gaseous ozone, Nd:YAG laser and control (no additional disinfection methods). Scanning electron microscope analysis was made for each group (n = 2). A resin cement was used for luting the posts. For push-out test, each root was cut horizontally (two cervical, two middle and two apical). Statistical analyses were performed with one-way anova (α = 0.05). Fracture types were observed. There was no statistically significant difference between the groups (P > 0.05). There were statistically significant differences in cervical and apical segments of laser and control groups (P < 0.05). The disinfection of the post spaces with Nd:YAG laser and ozone had no adverse effects on bond strength of glass-fibre post.
    背景与目标: :本研究的目的是研究气态臭氧和Nd:YAG激光对玻璃纤维后结合强度的影响。切下四十二个前颌臼齿前根,进行牙髓治疗,并用2.5%NaOCl冲洗。准备了职位空间,并将根分为三组(n = 14)。抗菌预处理如下:气态臭氧,Nd:YAG激光和对照(无其他消毒方法)。对每组进行扫描电子显微镜分析(n = 2)。使用树脂胶粘剂对接线柱进行浇铸。为了进行推出试验,水平切开每个根部(两个颈椎,两个中间和两个根尖)。使用单向方差分析(α= 0.05)进行统计分析。观察到骨折类型。两组之间无统计学差异(P> 0.05)。激光组和对照组的颈段和根尖段存在统计学差异(P <0.05)。用Nd:YAG激光和臭氧对立柱空间进行消毒对玻璃纤维立柱的粘结强度没有不利影响。
  • 【外源胶原酶和胆固醇酯酶对树脂-牙本质键持久性的影响。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Armstrong SR,Jessop JL,Vargas MA,Zou Y,Qian F,Campbell JA,Pashley DH
    BACKGROUND & AIMS: PURPOSE:The purpose of this work was to determine microtensile dentin bond strengths (microTBS) of dentin-resin composite bonds after three-month storage in artificial saliva containing either collagenase (COL) or cholesterol esterase (EST). The null hypothesis tested is that the resin-dentin bond strength is equivalent for each storage medium at the tested storage times. MATERIALS AND METHODS:Resin composite was bonded to occlusal dentin, and microTBS specimens were formed and stored in the artificial saliva, COL, EST, or synthetic oil. After 24 h and 12-week storage, microTBS was determined and failure modes were characterized by SEM. The interfacial ultrastructure was evaluated by transmission electron microscopy as unstained and stained sections (phosphotungstic acid/uranyl acetate). Statistical analysis was performed by ANOVA and Weibull survival analyses at the 0.05 level of statistical significance. RESULTS:There were significantly weaker bond strengths after 12 weeks for all experimental storage media (p < 0.001). Artificial saliva containing EST lowered bond strengths to a significantly greater extent than did COL after 12 weeks of storage, while no difference between these groups could be discerned after 24 h. Therefore, the null hypothesis of this experiment is rejected. CONCLUSION:Exogenous enzymatic challenge to resin-dentin bonds decreased bond durability only with EST. However, when further challenges to ideal infiltration of the comonomers into the hybrid layer were carried out using inadequate removal of solvent, additional alterations in hybrid layer ultrastructure were discerned by TEM that may represent different potential degradative processes. The contribution of endogenous enzymatic challenges to the primary degradative process, ie, hydrolysis, is unknown and deserves continued attention.
    背景与目标: 目的:这项工作的目的是确定在含有胶原酶(COL)或胆固醇酯酶(EST)的人工唾液中储存三个月后牙本质-树脂复合键的微拉伸牙本质粘合强度(microTBS)。测试的原假设是在测试的存储时间下每种存储介质的树脂-牙本质粘合强度均相等。
    材料与方法:将树脂复合材料粘结到牙本质牙本质上,形成microTBS标本并保存在人工唾液,COL,EST或合成油中。储存24小时和12周后,确定了microTBS,并通过SEM表征了失效模式。通过透射电子显微镜评价界面超微结构为未染色和染色的切片(磷钨酸/乙酸铀酰)。通过ANOVA和Weibull生存分析以0.05的统计显着性水平进行统计分析。
    结果:所有实验存储介质在12周后粘合强度均显着降低(p <0.001)。贮藏12周后,含有EST的人工唾液与COL相比,其结合强度降低的幅度要大得多,而24小时后未发现这两组之间的差异。因此,该实验的原假设被拒绝了。
    结论:外源酶对树脂-牙本质键的挑战仅通过EST降低了键的持久性。然而,当通过不充分去除溶剂对共聚单体向理想的渗透入杂化层的进一步挑战时,TEM可以看出杂化层超微结构的其他变化,这可能代表了不同的潜在降解过程。内源性酶挑战对主要降解过程(即水解)的贡献尚不清楚,值得继续关注。
  • 【beta4Thr-beta73Asp氢键在HbS聚合物中的作用以及由含多核簇形成的结构域。】 复制标题 收藏 收藏
    DOI:10.1021/bi800149u 复制DOI
    作者列表:Adachi K,Ding M,Surrey S
    BACKGROUND & AIMS: :Fiber formation and domain formation from deoxy-HbS as well as from beta4 and beta73 HbS variants were investigated after temperature jump using DIC microscopy to gain a basic understanding of the determinants involved. Oversaturated deoxy-HbS generated numerous 14-stranded fibers and formed ovoid-shaped, multispherulitic domains. Domain number increased linearly as a function of time. Oversaturated deoxy-alpha2beta2(E6V,T4S) also generated time-dependent, ovoid-shaped spherulitic domains like HbS and alpha 2beta2(E6V,D73H) in the deoxy form. In contrast, alpha 2beta2(E6V,T4Y) and HbC-Harlem (alpha2beta2(E6V,D73N)) in the deoxy form generated time-dependent, ball-shaped domains containing many straight, crystalline-like fibers without evidence of branching. Some of these domains formed large needlelike crystals after overnight incubation. The inhibitory effect on polymer formation by beta4Tyr in HbS was stronger than that by beta4Ser but weaker than that by beta73Asn or beta73Leu. In contrast, both deoxy- and oxy-alpha2beta2(E6V,T4V) promoted formation of tiny, disordered amorphous aggregates without a delay time like oxy-HbS, which is in contrast to formation after a delay time of needlelike fibers for alpha 2beta2(E6V,D73L). Solubilities for both deoxy- and oxy-alpha 2beta2(E6V,T4V) were similar to that of deoxy-alpha 2beta2(E6V,D73H) but approximately 10-fold lower than that of deoxy-HbS. These results suggest that the strength of the hydrogen bond between beta4Thr and beta73Asp and the balance between the hydrogen bond and beta6Val hydrophobic interactions in deoxy-HbS polymers control formation of different types of fibers in a single domain or lead to formation of disordered, non-nucleated amorphous aggregates. These results also lead to a model in which multinucleation rather than a single-nucleation event occurs in a single cluster to generate numerous fibers growing from a single domain.
    背景与目标: :在温度跃变后,使用DIC显微镜研究了脱氧HbS以及beta4和beta73 HbS变体的纤维形成和结构域形成,以基本了解所涉及的决定因素。过饱和的脱氧HbS生成了许多14股纤维,并形成了卵形的多球状结构域。域名随时间线性增加。过饱和的脱氧α2beta2(E6V,T4S)还生成了时间依赖性的卵形球状结构域,如脱氧形式的HbS和α2beta2(E6V,D73H)。相反,脱氧形式的α2beta2(E6V,T4Y)和HbC-Harlem(alpha2beta2(E6V,D73N))产生时间相关的球形结构域,其中包含许多直的晶体状纤维而无分支迹象。这些结构域中的一些在过夜温育后形成大的针状晶体。 beta4Tyr在HbS中对聚合物形成的抑制作用强于beta4Ser,但弱于beta73Asn或beta73Leu。相反,脱氧-和氧-α2beta2(E6V,T4V)都促进了无序的细小无定形聚集体的形成,而没有像氧-HbS这样的延迟时间,这与针状纤维延迟时间后形成α2β2(E6V)形成对比,D73L)。脱氧-α2beta2(E6V,T4V)的溶解度均与脱氧-α2beta2(E6V,D73H)相似,但比脱氧-HbS的溶解度低约10倍。这些结果表明,脱氧-HbS聚合物中beta4Thr和beta73Asp之间的氢键强度以及氢键和beta6Val疏水相互作用之间的平衡控制了单个域中不同类型纤维的形成,或导致无序,非-有核无定形聚集体。这些结果还导致了一个模型,在该模型中,在单个簇中发生多核而不是单核事件,以生成从单个域生长的大量纤维。
  • 【通过循环电外科切除术成功治疗由于囊性宫颈内异症破裂而引起的大量出血。】 复制标题 收藏 收藏
    DOI:10.1016/j.fertnstert.2007.04.011 复制DOI
    作者列表:Iwase A,Goto M,Kurotsuchi S,Harata T,Kaseki S,Kikkawa F
    BACKGROUND & AIMS: OBJECTIVE:To report a case of cystic cervical endometriosis that caused a massive hemorrhage due to rupture of a cyst and successful management with a loop electrosurgical excision procedure (LEEP). DESIGN:Case report. SETTING:University Hospital. PATIENT:A 37-year-old nulliparous woman. INTERVENTION(S):Medical management including surgical treatment. MAIN OUTCOME MEASURE(S):Clinical follow-up and pathologic diagnosis. RESULT(S):A hemorrhagic cystic cervical mass was excised with emergent LEEP. The mass was found to be cervical endometriosis. There was no evidence of recurrence until 1 year after excision. CONCLUSION(S):Cystic formation of cervical endometriosis--like ovarian endometrioma, which causes a massive hemorrhage due to rupture--is extremely rare, although cervical endometriosis is generally asymptomatic. Hysterectomy is considered in such cases but can be avoided via LEEP that incorporates partial excision of the uterine cervix.
    背景与目标: 目的:报道一例因囊肿破裂而导致大出血的囊性宫颈子宫内膜异位症患者,并采用环行电外科切除术(LEEP)成功治疗。
    设计:病例报告。
    单位:大学医院。
    患者:一位37岁的未产妇。
    干预措施:医疗管理,包括外科治疗。
    主要观察指标:临床随访和病理诊断。
    结果:出血的囊性宫颈肿块被紧急LEEP切除。发现该肿块是宫颈子宫内膜异位症。直到切除后1年,才有复发的迹象。
    结论:尽管通常子宫内膜异位症无症状,但很少发生膀胱内膜异位症的囊性形成(如卵巢内膜瘤,由于破裂而引起大量出血)。在这种情况下,可以考虑行子宫切除术,但可以通过合并子宫部分切除的LEEP手术来避免。
  • 【用于蛋白质工程的序列特异性Ni(II)依赖性肽键水解:活性序列优化。】 复制标题 收藏 收藏
    DOI:10.1016/j.jinorgbio.2013.07.037 复制DOI
    作者列表:Protas AM,Ariani HH,Bonna A,Polkowska-Nowakowska A,Poznański J,Bal W
    BACKGROUND & AIMS: :In previous studies we showed that Ni(II) ions can hydrolytically cleave a peptide bond preceding Ser/Thr in peptides of a general sequence RN-(Ser/Thr)-Xaa-His-Zaa-RC, where RN and RC are any peptide sequences. A peptide library screening, assisted by accurate measurements of reaction kinetics for selected peptides, demonstrated the preference for bulky and aromatic residues at variable positions Xaa and Zaa [A. Krężel, E. Kopera, A.M. Protas, A. Wysłouch-Cieszyńska, J. Poznański, W. Bal, J. Am. Chem. Soc., 132 (2010) 3355-3366]. In this work we used a similar strategy to find out whether the next residue downstream to Zaa may influence the reaction rate. Using an Ac-Gly-Ala-Ser-Arg-His-Zaa-Baa-Arg-Leu-NH2 library, with Zaa and Baa positions containing all common amino acids except of Cys, we found a very strong preference for aromatic residues in both variable positions. This finding significantly limits the range of useful Xaa, Zaa and Baa substitutions, thus facilitating the search for optimal sequences for protein engineering applications [E. Kopera, A. Belczyk-Ciesielska, W. Bal, PLoS One 7 (2012) e36350].
    背景与目标: :在先前的研究中,我们表明,Ni(II)离子可以水解切割通用序列RN-(Ser / Thr)-Xaa-His-Zaa-RC的肽中Ser / Thr之前的肽键,其中RN和RC是肽序列。通过精确测量所选肽的反应动力学,进行肽库筛选,证明了在可变位置Xaa和Zaa上优先选择大体积和芳香族残基[A. Krężel,E。Kopera,上午Protas,A。Wysłouch-Cieszyńska,J。Poznański,W。Bal,J。Am。化学Soc。,132(2010)3355-3366]。在这项工作中,我们使用了类似的策略来确定Zaa下游的下一个残基是否会影响反应速率。使用Ac-Gly-Ala-Ser-Arg-His-Zaa-Baa-Arg-Leu-NH2文库,其中Zaa和Baa位置包含除Cys以外的所有常见氨基酸,我们发现这两种氨基酸都非常倾向于芳香族残基可变位置。这一发现大大限制了有用的Xaa,Zaa和Baa取代的范围,从而促进了蛋白质工程应用的最佳序列的搜索[E. Kopera,A. Belczyk-Ciesielska,W. Bal,PLoS One 7(2012)e36350]。
  • 【过氧化物酶远端位点的氢键网络:Asn70-> Asp辣根过氧化物酶突变体的光谱性质。】 复制标题 收藏 收藏
    DOI:10.1021/bi9706172 复制DOI
    作者列表:Tanaka M,Nagano S,Ishimori K,Morishima I
    BACKGROUND & AIMS: The distal His in peroxidases forms a hydrogen bond with the adjacent Asn, which is highly conserved among many plant and fungal peroxidases. Our previous work [Nagano, S., Tanaka, M., Ishimori, K., Watanabe, Y., & Morishima, I. (1996) Biochemistry 35, 14251-14258] has revealed that the replacement of Asn70 in horseradish peroxidase C (HRP) by Val (N70V) and Asp (N70D) discourages the oxidation activity for guaiacol, and the elementary reaction rate constants for the mutants was decreased by 10-15-fold. In order to delineate the structure-function relationship of the His-Asn couple in peroxidase activity, heme environmental structures of the HRP mutant, N70D, were investigated by CD, 1H NMR, and IR spectroscopies as well as Fe2+/Fe3+ redox potential measurements. While N70D mutant exhibited quite similar CD spectra and redox potential to those of native enzyme, the paramagnetic NMR spectrum clearly showed that the hydrogen bond between the distal His and Asp70 is not formed in the mutant. The disappearance of the splitting in the 1H NMR signal of heme peripheral 8-methyl group observed in 50% H2O/50% D2O solution of N70D-CN suggests that the hydrogen bond between the distal His and heme-bound cyanide is also disrupted by the mutation, which was supported by the low C-N vibration frequency and large dissociation constant of the heme-bound cyanide in the mutant. Together with the results from various spectroscopies and redox potentials, we can conclude that the improper positioning of the distal His induced the cleavages of the hydrogen bonds around the distal His, resulting in the substantial decrease of the catalytic activity without large structural alterations of the enzyme. The His-Asn hydrogen bond in the distal site of peroxidases, therefore, is essential for the catalytic activity by controlling the precise location of the distal His.

    背景与目标: 过氧化物酶的远端His与相邻的Asn形成氢键,在许多植物和真菌的过氧化物酶中高度保守。我们以前的工作[Nagano,S.,Tanaka,M.,Ishimori,K.,Watanabe,Y.&Morishima,I.(1996)Biochemistry 35,14251-14258]揭示了辣根过氧化物酶C中Asn70的替代。 Val(N70V)和Asp(N70D)(HRP)抑制了愈创木酚的氧化活性,并且突变体的基本反应速率常数降低了10-15倍。为了描述过氧化物酶活性中His-Asn对的结构-功能关系,通过CD,1H NMR和IR光谱以及Fe2 / Fe3氧化还原电势测量研究了HRP突变体N70D的血红素环境结构。尽管N70D突变体显示出与天然酶非常相似的CD光谱和氧化还原电位,但顺磁NMR光谱清楚地表明,在该突变体中未形成远端His和Asp70之间的氢键。在N70D-CN的50%H2O / 50%D2O溶液中观察到的血红素外围8-甲基的1H NMR信号分裂的消失表明,His末端和与血红素结合的氰化物之间的氢键也被氢键破坏。较低的CN振动频率和突变体中血红素结合氰化物的较大解离常数为突变提供了支持。结合各种光谱学和氧化还原电势的结果,我们可以得出结论,His末端的不正确定位导致了His末端周围氢键的裂解,导致催化活性显着下降,而酶的结构没有很大变化。 。因此,过氧化物酶远端的His-Asn氢键通过控制远端His的精确位置,对于催化活性至关重要。

  • 【使用三种粘合剂填料浓度的陶瓷托板的剪切,扭转和拉伸强度。】 复制标题 收藏 收藏
    DOI:10.1016/0889-5406(91)70062-2 复制DOI
    作者列表:Ostertag AJ,Dhuru VB,Ferguson DJ,Meyer RA Jr
    BACKGROUND & AIMS: :The effect of changes in adhesive filler concentration on the shear, torsional, and tensile bond strength of a chemical, a mechanical, and a chemical/mechanical retained ceramic bracket was evaluated. Two hundred ten bovine teeth were bonded with one of three ceramic brackets using a 30%, 55%, or 80% filled adhesive. The brackets were debonded with a shear, torsional, or tensile force to test the bond strength and the site of bond failure. No significant difference was found in the shear, torsional, or tensile bond strength of each ceramic bracket type in relation to changes in the adhesive filler concentration. However, there was a trend toward increased bond strength with increasing filler concentration. Combining the data according to adhesive type revealed that the 80% filled adhesive displayed a significantly greater shear bond strength than the 30% or 55% filled adhesive and a greater torsional bond strength than the 30% filled adhesive. This supports the hypothesis of increased bond strength with increased adhesive filler concentration. The mechanically retained ceramic bracket showed greater shear bond strength and maximum shear bond strength in torsion than the chemical or chemical/mechanical retained ceramic bracket. The tensile bond strength of the mechanically retained ceramic bracket was similar to that of metal brackets reported in other studies, and the failure site was at the bracket-adhesive interface.
    背景与目标: :评估了粘合剂填充剂浓度变化对化学,机械和化学/机械固持陶瓷支架的剪切,扭转和拉伸粘合强度的影响。使用30%,55%或80%的填充胶将210个牛齿与三个陶瓷托槽之一粘合在一起。用剪切力,扭转力或拉力将托槽脱胶,以测试粘结强度和粘结失效部位。相对于粘合剂填料浓度的变化,每种陶瓷托槽类型的剪切,扭转或拉伸粘结强度均未发现显着差异。然而,随着填料浓度的增加,粘结强度有增加的趋势。根据粘合剂类型组合数据表明,与30%或55%填充的粘合剂相比,填充80%的粘合剂显示出明显更高的剪切粘合强度,并且与30%填充的粘合剂相比具有更高的扭转粘合强度。这支持了随着胶粘剂填料浓度的增加而增加粘合强度的假设。与化学或化学/机械固持的陶瓷支架相比,机械固持的陶瓷支架表现出更大的扭转剪切强度和最大抗剪强度。机械保留的陶瓷托槽的拉伸粘结强度与其他研究中报道的金属托槽相似,并且破坏部位位于托槽与胶粘剂的界面。
  • 【跟腱自发性破裂和库欣氏病。案例报告。】 复制标题 收藏 收藏
    DOI:10.1016/j.ando.2008.06.003 复制DOI
    作者列表:Batisse M,Somda F,Delorme JP,Desbiez F,Thieblot P,Tauveron I
    BACKGROUND & AIMS: :Spontaneous rupture of Achilles tendon is observed in patients with tumors, metabolic disorders, infections and systemic diseases. Fluoroquinolones may cause tendinopathies. In addition, spontaneous rupture uncommonly occurs in Cushing's syndrome. We report a case of Cushing's disease revealed by recurrent rupture of Achilles tendon. Tendon tears are described in patients receiving long-term steroid treatment, probably via a mechanism similar to that one occurring in Cushing's syndrome. Although exceptional, this diagnosis should be discussed in patients with spontaneous rupture of Achilles tendon.
    背景与目标: :患有肿瘤,代谢紊乱,感染和全身性疾病的患者中观察到跟腱自发破裂。氟喹诺酮类可能引起肌腱病。另外,库欣氏综合征很少发生自发性破裂。我们报告了由跟腱复发引起的库欣病病例。在接受长期类固醇治疗的患者中描述了肌腱撕裂,可能是通过类似于库欣综合征的一种机制。尽管例外,但该诊断应在跟腱自发性破裂的患者中进行讨论。
  • 【病例报告:产妇子宫卵巢血管破裂。】 复制标题 收藏 收藏
    DOI:10.1007/s00404-008-0751-z 复制DOI
    作者列表:Moreira A,Reynolds A,Baptista P,Costa AR,Bernardes J
    BACKGROUND & AIMS: CASE:We report the rare case of a 39-year-old woman who had an intra-partum hemoperitoneum that resulted from spontaneous rupture of the utero-ovarian vessels. During the expulsive efforts, the patient repeatedly complained of bilateral shoulder discomfort and some respiratory difficulty. Because she had hemodynamic instability and an abdomino-pelvic ultrasound revealed the presence of extensive free fluid within the peritoneal cavity, the patient underwent an exploratory laparotomy. The surgery revealed an extensive laceration of the anterior leaf of the left broad ligament and vesico-uterine peritoneum, and active bleeding from the utero-ovarian vessels with no evidence of uterine rupture. CONCLUSION:Intra-partum haemoperitoneum resulting from rupture of the utero-ovarian vessels is a rare obstetrical emergency that needs rapid resuscitation with fluid and/or blood replacement and prompt surgical intervention.
    背景与目标: 案例:我们报告了一个罕见的病例,即一名39岁的妇女因子宫卵巢血管自发破裂而导致产后出血性腹膜炎。在进行驱逐努力期间,患者反复抱怨双侧肩部不适和呼吸困难。由于她的血液动力学不稳定,并且腹部盆腔超声检查显示腹膜腔内存在大量游离液,因此对该患者进行了探查性剖腹手术。手术显示左阔韧带和膀胱子宫腹膜前叶广泛裂伤,子宫卵巢血管活动性出血,无子宫破裂迹象。
    结论:子宫卵巢血管破裂引起的产后出血是一种罕见的产科急症,需要快速复苏并补充液体和/或血液并迅速进行手术干预。
  • 【利用分子内氢键增加NK(1)受体拮抗剂的中枢神经系统渗透。】 复制标题 收藏 收藏
    DOI:10.1021/jm010825z 复制DOI
    作者列表:Ashwood VA,Field MJ,Horwell DC,Julien-Larose C,Lewthwaite RA,McCleary S,Pritchard MC,Raphy J,Singh L
    BACKGROUND & AIMS: :This paper describes the synthesis and physical and biological effects of introducing different substituents at the alpha-position of the tryptophan containing neurokinin-1 receptor antagonist [(R)-2-(1H-indol-3-yl)-1-methyl-1-((S)-1-phenyl-ethylcarbamoyl)-ethyl]-carbamic acid benzofuran-2-ylmethyl ester (CI 1021). The described compounds all exhibit less than 5 nM binding affinities for the human neurokinin-1 receptor and selectivity over the tachykinin NK(2) and NK(3) receptor subtypes. Application of variable temperature nuclear magnetic resonance spectroscopy studies of the amide and urethane protons was utilized to determine the existence of an intramolecular hydrogen bond. This intramolecular hydrogen bond increases the apparent lipophilicity to allow increased central nervous system penetration and pharmacological activity (gerbil foot tap test) in the case of the highest affinity compound [(S)-1-dimethylaminomethyl-2-(1H-indol-3-yl)-1-((S)-1-phenyl-ethylcarbamoyl)-ethyl]-carbamic acid benzofuran-2-ylmethyl ester (PD 174424) over those analogues that could not form an intramolecular hydrogen bond.
    背景与目标: :本文描述了在含有色氨酸的神经激肽1受体拮抗剂[(R)-2-(1H-indol-3-yl)-1-甲基- 1-((S)-1-苯基-乙基氨基甲酰基)-乙基]-氨基甲酸苯并呋喃-2-基甲基酯(CI 1021)。所描述的化合物均对人神经激肽-1受体的结合亲和力低于5 nM,并且对速激肽NK(2)和NK(3)受体亚型的选择性更高。酰胺和氨基甲酸酯质子的可变温度核磁共振光谱研究的应用被用来确定分子内氢键的存在。在最高亲和力化合物[(S)-1-二甲基氨基甲基-2-(1H-indol-3-)的情况下,此分子内氢键增加了表观亲脂性,从而增加了中枢神经系统的渗透性和药理活性(沙土鼠脚踏试验)。 )-1-(((S)-1-苯基-乙基氨基甲酰基)-乙基]-氨基甲酸苯并呋喃-2-基甲基酯(PD 174424)上那些不能形成分子内氢键的类似物。
  • 【超越可旋转键数:在单个描述符中捕获3D构象灵活性。】 复制标题 收藏 收藏
    DOI:10.1021/acs.jcim.6b00565 复制DOI
    作者列表:Wicker JG,Cooper RI
    BACKGROUND & AIMS: :A new molecular descriptor, nConf20, based on chemical connectivity, is presented which captures the accessible conformational space of a molecule. Currently the best available two-dimensional descriptors for quantifying the flexibility of a particular molecule are the rotatable bond count (RBC) and the Kier flexibility index. We present a descriptor which captures this information by sampling the conformational space of a molecule using the RDKit conformer generator. Flexibility has previously been identified as a key feature in determining whether a molecule is likely to crystallize or not. For this application, nConf20 significantly outperforms previously reported single-variable classifiers and also assists rule-based analysis of black-box machine learning classification algorithms.
    背景与目标: :提出了一种基于化学连接性的新分子描述子nConf20,该描述子捕获了分子可访问的构象空间。当前,用于量化特定分子的柔韧性的最佳可用二维描述符是可旋转键数(RBC)和Kier柔韧性指数。我们提供了一个描述符,该描述符通过使用RDKit构象异构体生成器对分子的构象空间进行采样来捕获此信息。先前已将柔韧性确定为确定分子是否可能结晶的关键特征。对于此应用程序,nConf20明显优于以前报告的单变量分类器,并且还可以帮助基于规则的黑盒机器学习分类算法分析。
  • 【修复系统对新型CAD / CAM修复材料的抗剪强度。】 复制标题 收藏 收藏
    DOI:10.1111/jopr.12564 复制DOI
    作者列表:Üstün Ö,Büyükhatipoğlu IK,Seçilmiş A
    BACKGROUND & AIMS: PURPOSE:To evaluate the bond strength of repair systems (Ceramic Repair, Clearfil Repair) to computer-aided design/computer-assisted machining (CAD/CAM) restorative materials (IPS e.max CAD, Vita Suprinity, Vita Enamic, Lava Ultimate). MATERIALS AND METHODS:Thermally aged CAD/CAM restorative material specimens (5000 cycles between 5°C and 55°C) were randomly divided into two groups according to the repair system: Ceramic Repair (37% phosphoric acid + Monobond-S + Heliobond + Tetric N Ceram) or Clearfil Repair (40% phosphoric acid + mixture of Clearfil Porcelain Bond Activator and Clearfil SE Bond Primer + Clearfil SE Bond + Filtek Z250). The resin composite was light-cured on conditioned specimens. All specimens were stored in distilled water at 37°C for 24 hours and then additionally aged for 5000 thermal cycles. The shear bond strength test was performed using a universal testing machine (0.5 mm/min). Two-way ANOVA was used to detect significance differences according to the CAD/CAM material and composite repair system factors. Subgroup analyses were conducted using the least significant difference post-hoc test. RESULTS:The results of two-way ANOVA indicated that bond strength values varied according to the restorative materials (p < 0.05). No significant differences were observed between the CAD/CAM restorative materials (p > 0.05), except in the Vita Suprinity group (p < 0.05). Moreover, no differences were observed between the repair systems. CONCLUSIONS:Both the Clearfil and Ceramic repair systems used in the study allow for successful repairs.
    背景与目标: 目的:评估修复系统(陶瓷修复,Clearfil修复)与计算机辅助设计/计算机辅助加工(CAD / CAM)修复材料(IPS e.max CAD,Vita Suprinity,Vita Enamic,Lava Ultimate)的结合强度。
    材料与方法:根据修复系统,将热老化的CAD / CAM恢复材料样品(5°C至55°C之间的5000个循环)随机分为两组:陶瓷修复(37%磷酸Monobond-S Heliobond Tetric N Ceram磷酸) )或Clearfil修复(Clearfil瓷质粘结活化剂和Clearfil SE粘结底漆Clearfil SE粘结Filtek Z250的40%磷酸混合物)。将树脂复合材料在条件试样上光固化。将所有样品在37°C的蒸馏水中保存24小时,然后再老化5000个热循环。使用万能试验机(0.5mm / min)进行抗剪强度试验。根据CAD / CAM材料和复合材料修复系统因素,使用双向ANOVA来检测显着性差异。使用最低显着差异事后检验进行亚组分析。
    结果:双向方差分析的结果表明,结合强度值根据修复材料的不同而不同(p <0.05)。除了Vita Suprinity组(p <0.05)外,CAD / CAM恢复材料之间没有观察到显着差异(p> 0.05)。此外,修复系统之间未发现差异。
    结论:研究中使用的Clearfil和Ceramic修复系统均可成功修复。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录