新麻醉药静松灵生物转化的研究

静松灵[2-(2,4-二甲基苯胺基)-4,5-二氢噻唑,XT]是国内合成的麻醉物,经ip给药后,从大鼠尿中分离、纯化、鉴定了四个代谢产物。MB₁即XT原形;MB₃及MA₂互为异构体,分别为2位、4位甲基氧化为羧基的产物;MA₁则4位甲基氧化为羧基,二氢噻唑环中4¹位亚甲基氧化为羰基。初步实验表明:代谢产物MB₃,MA²,MA₁的药效与毒性均远低于原形药,大鼠与小鼠对XT的转化机制相近,但也存在种属的差异。     

The reversal of profound mivacurium-induced neuromuscular blockade

Purpose

Mivacurium is metabolized by plasma cholinesterase catalyzed ester hydrolysis. Acetylcholinesterase antagonists used in the reversal of muscle relaxation may also inhibit plasma cholinesterase and, therefore, delay the hydrolysis of mivacurium. The clinical interaction between acetylcholinesterase antagonists and mivacurium induced neuromuscular blockade was studied.

Method

Intraoperative muscle relaxation was maintained with a mivacurium infusion to achieve a constant intense block (first twitch, T¹, 2–3% of control). Patients were randomly divided into three groups. Patients in Group 1 received no anticholinesterase, in Group 2 neostigmine 0.07 mg · kg^?1, and in Group 3 edrophonium 1 mg · kg^?1. The times between termination of the mivacurium infusion (Group 1) or the administration of the anticholinesterase (Groups 2 and 3) to 25%, 50%, 75% and 95% T₁ recovery, and to 50%, 70% and 90% recovery in the ratio, T₄/T₁ (TR) were recorded.

Result

In the neostigmine Group, T₁ recovery to 25%, 50% and 75% ( 2.32 ± 1.41, 3.90 ± 1.85 and 6.88 ± 2.66 min) was accelerated compared with control (3.36 ± 1.34, 5.78 ± 2.22, and 8.58 ± 3.60, and), but recovery to 95% (18.53 ± 9.09 vs 13.29 ± 5.24 min) was delayed. Also, TR recovery to 50%, 70%, and 90% was slower (14.47 ± 8.73, 21.25 ± 11.06 and 31.37 ± 12.11 min vs 11.75 ± 3.74, 13.78 ± 4.39 and 17.86 ± 6.44 min). However, all T₁ and TR recovery times were decreased in the edrophonium group (0.88 ± 0.51, 2.00 ± 1.50, 4.97 ± 2.96, and 9.35 ± 5.24 min for T₁ and 6.86 ± 3.93, 9.05 ± 4.51 and 12.24 ± 6.66 min for TR).

Conclusion

Neostigmine reversal of intense mivacurium neuromuscular block should be avoided, as this may result in prolongation of the block.     

中药山豆根的形态组织学研究

对目前国内作山豆根用的9种不同植物来源的生药进行了形态组织学的比较研究,观察并描述了它们的生药性状和组织构造,并列出了生药的分种检索表。     

Size Effects in Internal Friction of Nanocrystalline Aluminum Films

Al thin film is extensively used in micro-electromechanical systems (MEMS) and electronic interconnections; however, most previous research has concentrated on their quasi-static properties and applied their designs on larger scales. The present study designed a paddle-like cantilever specimen with metal films deposited on the upper surface to investigate the quasi-static properties of Al thin film at room temperature under high vacuum conditions at microscopic scales. Energy loss was determined using a decay technique in the oscillation amplitude of a vibrating structure following resonant excitation. Grain size and film thickness size were strictly controlled considering the quasi-static properties of the films. This study found that the internal friction of ultra-thin and thin Al films was more dependent on the grain boundaries than film thickness.     

Gold nanoclusters as prospective carriers and detectors of pramipexole

Pramipexole (PPX) is known in the treatment of Parkinson''s disease and restless legs syndrome. We carried out a theoretical investigation on pramipexole–Au cluster interactions for the applications of drug delivery and detection. Three Au_N clusters with sizes N = 6, 8 and 20 were used as reactant models to simulate the metallic nanostructured surfaces. Quantum chemical computations were performed in both gas phase and aqueous environments using density functional theory (DFT) with the PBE functional and the cc-pVDZ-PP/cc-pVTZ basis set. The PPX drug is mainly adsorbed on gold clusters via its nitrogen atom of the thiazole ring with binding energies of ca. −22 to −28 kcal mol⁻¹ in vacuum and ca. −18 to −24 kcal mol⁻¹ in aqueous solution. In addition to such Au–N covalent bonding, the metal–drug interactions are further stabilized by electrostatic effects, namely hydrogen-bond NH⋯Au contributions. Surface-enhanced Raman scattering (SERS) of PPX adsorbed on the Au surfaces and its desorption process were also examined. In comparison to Au₈, both Au₆ and Au₂₀ clusters undergo a shorter recovery time and a larger change of energy gap, being possibly conducive to electrical conversion, thus signaling for detection of the drug. A chemical enhancement mechanism for SERS procedure was again established in view of the formation of nonconventional hydrogen interactions Au⋯H–N. The binding of PPX to a gold cluster is expected to be reversible and triggered by the presence of cysteine residues in protein matrices or lower-shifted alteration of environment pH. These findings would encourage either further theoretical probes to reach more accurate views on the efficiency of pramipexole–Au interactions, or experimental attempts to build appropriate gold nanostructures for practical trials, harnessing their potentiality for applications.

Gold clusters as prospective carriers and detectors of pramipexole.     

Preparation of Mn2O3/MIL-100(Fe) composite and its mechanism for enhancing the photocatalytic removal of rhodamine B in water

In this study, Mn₂O₃/MIL-100(Fe) composite was successfully synthesized by the hydrothermal method and applied for photocatalytic removal of rhodamine B (RhB) in water. The physical and chemical properties of the synthesized materials were characterized by XRD, FTIR, SEM, UV-visible, and BET analyses. Experimental results showed a great enhancement in the photocatalytic ability of the Mn₂O₃/MIL-100(Fe) composite as compared to individual Mn₂O₃ or MIL-100(Fe) under visible light and persulfate activation. The affecting factors such as pH, photocatalyst dose, RhB concentration, and Na₂S₂O₈ concentration were investigated to find out the best conditions for efficient photocatalysis. By conducting a radical quenching test, all radicals of HO˙, SO₄˙⁻, ¹O₂, and O₂˙⁻ were found to be important in photocatalytic decomposition. The mechanism was proposed for the enhancement of photocatalytic RhB removal via band potential calculation, charge separation, surface redox reaction, and key reactive oxidation species. With its durability, reusability, and high efficiency, the Mn₂O₃/MIL-100(Fe) composite emerges as a potential photocatalyst working under visible light for application in wastewater treatment.

Effective charge transfer enhances the persulfate activation of Mn₂O₃/MIL-100(Fe) for photocatalytic removal of RhB under LED-generated visible light.     

Efficient nickel or copper oxides decorated graphene–polyaniline interface for application in selective methanol sensing

Graphene sheets decorated with nickel or copper oxides that were anchored on polyaniline (denoted as PANI-graphene/NiO and PANI-graphene/CuO) were prepared by a simple, easy to-control electrochemical method and applied as novel materials for sensitive and selective methanol sensing. The fabricated sensors exhibited good electrocatalytic activity, appropriate dynamic linear range (20–1300 mM), sensitivity (0.2–1.5 μA mM⁻¹ cm⁻²) and excellent selectivity towards methanol. It should be highlighted from the selectivity tests that no significant interference was observed from ethanol and other alcohols. To our best knowledge, using inexpensive but efficient transition metals like Ni, Cu instead of Pt, Pd and their composites with PANI, graphene would be scientifically novel and practically feasible approach for sensor fabrication that could be potentially used to identify methanol adulteration in counterfeit alcoholic beverages.

PANI/graphene/NiO or PANI/graphene/CuO were prepared by a simple, easy to-control electrochemical method and applied as novel materials for sensitive and selective methanol sensing.     

转化生长因子β1在大鼠纤维化腹膜组织中的表达及作用

目的:检测转化生长因子β1在腹膜透析大鼠腹膜内表达,并探讨其在腹膜纤维化中的意义。方法:实验于2005-06/2006-03在中南大学湘雅二医院肾内科实验室完成。①实验材料:雄性SD大鼠,体质量180～240g,由中南大学湘雅二医院动物实验中心提供。②实验方法:将28只大鼠按随机数字表随机分为4组,每组7只。正常对照组不予任何干预;生理盐水组腹腔注射20mL生理盐水;低糖透析液组腹腔注射20mL1.5%葡萄糖透析液;高糖透析液组腹腔注射20mL4.25%葡萄糖透析液,均为1次/d。4周后,向大鼠腹腔注射4.25%葡萄糖腹膜透析液20mL,4h后于大鼠右下腹缓慢插入带有多个侧孔的10号静脉留置针,缓慢低位引流腹透液,量取引流液。③实验评估:取大鼠壁层腹膜组织,以苏木素-伊红染色,镜下测量腹膜厚度,采用免疫组织化学方法检测大鼠腹膜中转化生长因子β1及纤连蛋白。结果:28只大鼠均进入结果分析。①高糖透析液组、低糖透析液组超滤量均明显低于正常对照组与生理盐水组,并且高糖透析液组超滤量明显少于低糖透析液组(P均<0.05)。②高糖透析液组腹膜明显增厚,表面粗糙,间皮细胞肿胀,脱落,间皮下有大量血管生成以及胶原纤维沉积,还可见单核细胞等炎症细胞浸润,与其他组比较,腹膜厚度明显增加(P<0.05)。③高糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于其他组;低糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于正常对照组与生理盐水组(P<0.05)。④大鼠腹膜组织转化生长因子β1蛋白与纤连蛋白表达量、腹膜厚度之间呈明显的正相关(r=0.86,0.83,P<0.05)。结论:葡萄糖透析液可诱导腹膜组织转化生长因子β1明显上调,腹膜转化生长因子β1高表达与腹膜透析腹膜纤维化密切相关。     

Orthodontic care in suburban Cuyahoga County, Ohio: who provides treatment and whom do they treat?

It has been reported that orthodontic services are being provided to a larger segment of the population by an increasing number of providers. The present study surveyed the dental and orthodontic experiences of 10th grade students attending 16 public and two parochial high schools in suburban Cuyahoga County, Ohio, as well as two schools from the city of Cleveland. Questionnaires were distributed in the classroom and data obtained for 2808 students. Approximately 50% of the sample were girls with an average age of 15.5 +/- 0.8 years. Results of the survey revealed that 84% (2371/2808) had seen a dentist within the past year, and 37% (1047/2808) of the students had received orthodontic treatment from 171 different providers. Of those treated, 87.2% (913/1047) were treated by a specialist in orthodontics, 10.8% (114/1047) by a general dentist, and 0.7% (7/1047) by a pediatric dentist, with 1.3% missing or unknown (13/1047). Patients who had seen a dentist within the past year were more likely to have had orthodontic treatment. Only 7% of the untreated students were told by a dental professional that they needed braces compared with 71% of the treated group. Therefore, we conclude that orthodontic specialists provide most of the orthodontic services in the suburbs of Cuyahoga County, and visiting a general dentist positively influences the utilization of orthodontic services.