The reduction of 2-bromomethyl-3-methyl- and 2,3-bis-bromomethyl-1,4-naphthoquinones,potential bioreductive alkylating agents. Electrochemical and computational studies

In the present work, 2,3-dimethyl-1,4-naphthoquinones, substituted at one or both side chains with bromine were prepared and submitted to electrochemical studies (cyclic voltammetry and electrolysis), in aprotic medium (DMF + 0.1 mol l^?1 TBAP), using different electrodes (Hg, GC and Au), to observe the role of bromide, as a good leaving group, in their electroreductions. The cyclic voltammograms are complex. Combined results from CV, chronoamperometry and analysis of the products of electrolysis, mainly dimers and the parent unsubstituted quinone, allowed the qualitative definition of the electrodic mechanism for the reduction of the brominated quinones. A reversible electronic transfer to the quinonoid group followed by the cleavage of C–Br, in an EC type mechanism, more specifically a reductive elimination, is suggested. The quinonoid radical is generated and suffers dimerization to electroactive dimers or a second electron uptake, furnishing the anion that can be protonated to yield 2,3-dimethyl-1,4-naphthoquinone, also electroactive. The additional waves are probably related to the reduction of quinomethide-derived products, upon comparison with a synthetic dimer. Computational studies corroborate the electrochemical observations. Despite the lack of unequivocal proof of quinonemethide generation, its intermediacy is highly probable and this has been proved to be essential for the biological activity of these compounds.     

The effect of thermocycling on the bonding of different restorative materials to access opening through porcelain fused to metal restorations

PURPOSE

Porcelain fused to metal (PFM) crowns provide the best treatment option for teeth that have a large or defective restoration. More than 20% of teeth with PFM crowns or bridges require non-surgical root canal treatment (NSRCT). This may be due to the effect of restorative procedures and the possible leakage of bacteria and or their by-products, which leads to the demise of the tooth pulp. Thus, this study was planned to compare the ability of the restorative materials to seal perforated PFM specimens.

MATERIALS AND METHODS

The study evaluates the ability of amalgam, composite or compomer restorative materials to close perforated PFM specimen''s in-vitro. Ninety PFM specimens were constructed using Ni-Cr alloys and feldspathic porcelain, and then they were divided into 3 groups: amalgam (A), composite + Exite adhesive bond (B) and compomer + Syntac adhesive bond (C). All the PFM samples were embedded in an acrylic block to provide complete sealing of the hole from the bottom side. After the aging period, each group was further divided into 3 equal subgroups according to the thermocycling period (one week for 70 cycles, one month for 300 cycles and three months for 900 cycles). Each subgroup was put into containers containing dye (Pelikan INK), one maintained at 5℃ and the other at 55℃, each cycle for 30 sec time. The data obtained was analyzed by SPSS, 2006 using one way ANOVA test and student t-test and significant difference level at (P<.01).

RESULTS

The depth of dye penetration was measured at the interfaces of PFM and filling materials using Co-ordinate Vernier Microscope. The lowest levels of the dye penetration for the three groups, as well as subgroups were during the first week. The values of dye leakage had significantly increased by time intervals in subgroups A and C.

CONCLUSION

It was seen that amalgam showed higher leakage than composite while compomer showed the lowest level of leakage.     

Combined Effect of Smoking and Obesity on Coronary Heart Disease Mortality in Male Veterans: A 30-year Cohort Study

Objective Evidence is lacking regarding the combined effects of smoking and obesity on mortality from coronary heart disease in male veterans.This study aimed to explore the combined effect of smoking and obesity on coronary heart disease mortality in male veterans in China.Methods A cohort of 1,268 male veterans from 22 veteran centers in Xi’an(Shaanxi Province,China)were followed up once every 2 years from February 1,1987 to October 30,2016.The endpoint was death from any cause.The hazard ratio(HR)of each risk factor and the 95%confidence interval(CI)were calculated using a multivariate Cox proportional hazard model.Results The total follow-up was 24394.21 person-years;each subject was followed up for a mean duration of 19.24 years.By the end of the study,of the 1,268 veterans,889 had died,363 were alive,and 16 were lost to follow-up.Cox regression analysis results revealed that current smoking(HR:1.552,95%CI:1.074–2.243),obesity(HR:1.625,95%CI:1.024–2.581),and the combined effect of the two factors(HR:2.828,95%CI:1.520–5.262)were associated with coronary heart disease mortality.Conclusion Our results suggest that obese veterans who smoke might be an important target population for coronary heart disease mortality control.     

探讨中药处方分析运用在中药药学服务中的效果

目的:探讨中药处方分析运用在中药药学服务中的临床效果。方法:选取2018年3月-2018年6月-门诊中药房接受存在处方问题的164张中药处方作为研究对象。对所有处方进行中药处方分析,明确处方中存在的问题,并统计被干预处方的来源科室,最终与来源科室沟通纠正处方中存在的问题。结果:164例中药处方分析结果显示超量是主要的处方问题(占54.88%),其次为配伍禁忌(26.83%),二者均明显高于其他处方问题发生率(P<0.05);而问题处方来源主要集中在消化与肾病科、儿科、名中医科以及肿瘤与风湿科;164张问题处方经分析以及与来源科室沟通、修正后均满足中医药合理用药要求。结论:临床中药处方中超量、配伍禁忌等问题现象较为普遍,经中药处方分析可及时发现处方中存在的问题,对提高中医药应用的合理性与安全性、有效性具有重要的临床意义。     

Selective age-related changes in orientation perception

Orientation perception is a fundamental property of the visual system and an important basic processing stage for visual scene perception. Neurophysiological studies have found broader tuning curves and increased noise in orientation-selective neurons of senescent monkeys and cats, results that suggest an age-related decline in orientation perception. However, behavioral studies in humans have found no evidence for such decline, with performance being comparable for younger and older participants in orientation detection and discrimination tasks. Crucially, previous behavioral studies assessed performance for cardinal orientation only, and it is well known that the human visual system prefers cardinal over oblique orientations, a phenomenon called the oblique effect. We hypothesized that age-related changes depend on the orientation tested. In two experiments, we investigated orientation discrimination and reproduction for a large range of cardinal and oblique orientations in younger and older adults. We found substantial age-related decline for oblique but not for cardinal orientations, thus demonstrating that orientation perception selectively declines for oblique orientations. Taken together, our results serve as the missing link between previous neurophysiological and human behavioral studies on orientation perception in healthy aging.     

Local inhibition of GABA affects precedence effect in the inferior colliculus

The precedence effect is a prerequisite for faithful sound localization in a complex auditory environment, and is a physiological phenomenon in which the auditory system selectively suppresses the directional information from echoes. Here we investigated how neurons in the inferior colliculus respond to the paired sounds that produce precedence-effect illusions, and whether their firing behavior can be modulated through inhibition with gamma-aminobutyric acid （GABA）. We recorded extracellularly from 36 neurons in rat inferior colliculus under three conditions： no injection, injection with saline, and injection with gamma-aminobutyric acid. The paired sounds that produced precedence effects were two identical 4-ms noise bursts, which were delivered contralaterally or ipsilaterally to the recording site. The normalized neural responses were measured as a function of different inter-stimulus delays and half-maximal interstimulus delays were acquired. Neuronal responses to the lagging sounds were weak when the inter-stimulus delay was short, but increased gradually as the delay was lengthened. Saline injection produced no changes in neural responses, but after local gamma-arninobutyric acid application, responses to the lagging stimulus were suppressed. Application of gamma-aminobutyric acid affected the normalized response to lagging sounds, independently of whether they or the paired sounds were contralateral or ipsilateral to the recording site. These observations suggest that local inhibition by gamma-aminobutyric acid in the rat inferior colliculus shapes the neural responses to lagging sounds, and modulates the precedence effect.     

采用循证护理带教法提高护生内科临床实习效果的研究

目的：评价循证护理在临床带教中的运用效果。方法：选择在2009－2011学年内科护理临床带教过程中,将在某医院实习的高职高专护理专业的学生随机分成2组,一组采用循证护理的带教方法,一组采用传统的带教方法。结果：经调查问卷、考试试卷回收率、有效率均为100%,试验组(2008级)护生各项指标均优于对照组(2007级),差异有统计学意义(P＜0.05)。结论：内科护理临床带教过程中采用循证护理的带教方法,可促进学生学习积极性;有利于培养学生以实证为基础的护理理念;有利于提高学生研究能力;有利于促进院校教师的自我完善。     

光动力疗法治疗中、重度痤疮的疗效观察

目的:观察光动力疗法在中、重度痤疮治疗中的疗效及不良反应。方法:选取90例中重度痤疮患者,应用易妍光能净颜调护组结合光动力治疗仪进行治疗,对疗效及不良反应进行观察和记录。结果:经过3次光动力治疗后,90例中、重度痤疮患者,痊愈58例,显效25例,有效7例,无效0例,总有效率为92%。治疗过程中,仅有部分患者出现红斑、灼热感、轻度水肿、脱皮等不良反应,能自行缓解,且不影响后续治疗。结论:光动力疗法治疗中、重度痤疮简单、有效、安全,值得临床推广。     

冠状切口治疗复杂面中部骨折的疗效探讨

目的:探讨冠状切口手术治疗在复杂面中部骨折的临床治疗优势。方法:对我科应用冠状切口治疗复杂面中部骨折的36例患者进行回顾研究,比较其与传统方法的优势。结果:术后6个月,手术切口大多数都已愈合,无血肿,基本上无感染。瘢痕不明显,面中部外形对称,没有出现面神经损伤症状,头皮切口处毛发大多正常生长。骨折复位状况愈合良好,咬合关系、开口度正常,患者较为满意。结论:冠状切口手术能够有效的防止并发症出现,充分暴露手术视野,切口隐蔽,瘢痕不明显,值得临床推广应用。     

自拟方辨证治疗功能性便秘的临床疗效

为探讨自拟方辨证治疗功能性便秘的疗效,将120例功能性便秘患者随机分为对照组和观察组,各60例,对照组患者口服聚乙二醇4000散剂治疗,观察组根据中医辨证将患者进行分型（热秘型、气虚型、血虚型、阴虚型、阳虚型、肝郁型）,并采用自拟中药方分型进行治疗,对比观察两组患者治疗4周后及停药4周后的总体疗效。结果显示,观察组治疗4周后及停药4周后的总有效率均明显高于对照组,P＜O．05。结果表明,自拟方辨证治疗功能性便秘具有较好的临床疗效,而且疗效较持久。