凝胶渗透色谱-多角度激光散射联用技术研究 红芪多糖中4个组分分子特征

目的:测定红芪多糖3(HPS-3)中4个组分的绝对分子量,相对分子质量分布,均方根旋转半径(Rg),多分散系数(Mw/Mn)等分子特征参数,以均方根旋转半径(Rg)对重均分子量(Mw)作图,计算4个组分在溶液状态的构象。方法:采用凝胶渗透色谱-多角度激光散射(GPC-MALLS)联用技术,流动相为含0.02%NaN3的0.1 mol.L-1NaNO3溶液,Ultrahydro-gelTM1000,500色谱柱串联。结果:HPS-3的4个组分中,HPS-3-C的Mw最大(1.986×105g.mol-1);其次为HPS-3-B(1.113×105 g.mol-1)和HPS-3-D(8.457×104 g.mol-1);HPS-3-A的Mw最小(1.223×104 g.mol-1),而Rg最大(55.5 nm)。HPS-3-D相对分子质量分布范围最广,Mw/Mn 2.543。在流动相中,HPS-3-A为球型构象,HPS-3-C为无规则线团构象,HPS-3-B和HPS-3-D则均为高枝化度结构。结论:为进一步研究HPS-3中4个组分分子特征与其生物活性的关系提供必要依据。     

Phase angle is a useful bioelectrical marker for skeletal muscle quantity and quality in hospitalized elderly patients

To analyze whether phase angle (PhA) can be a useful bioelectrical marker for skeletal muscle quantity and quality in hospitalized elderly patients. Two hundred hospitalized elderly patients were included in this retrospective observational study. PhA was obtained by Bioelectrical Impedance Analysis, skeletal muscle area index (SMI) and skeletal muscle density (SMD) were measured at the third lumbar vertebra level in computed tomography images using SliceOmatic software. PhA was positively associated with SMD and SMI, with correlation coefficients of 0.629 and 0.674, respectively. Multiple logistic regression analysis showed that 1° reduction of PhA was significantly associated with low SMI [odds ratio (OR) = 4.331 (1.681–11.161)] and low SMD [OR = 6.418 (2.963–13.899)]. Receiver operating characteristic curve analysis showed that the area under the curve (AUC) for PhA to identify patients with low SMI was 0.772 for male and 0.784 for female; the AUC for PhA to identify low SMD patients was 0.829 for male and 0.812 for female; the AUC for PhA to identify low SMD combined with low SMD patients was 0.801 for male and 0.773 for female. The results of this study showed that PhA was highly related to SMI, which can indicate the quantity of skeletal muscle in the entire body, and was highly related to SMD, which can be used to assess skeletal muscle quality. Therefore, PhA may be a useful bioelectrical marker for skeletal muscle quantity and quality.     

Experimental Study on Mechanical Properties of Concrete at Super-Early Age

Few studies have reported the cohesion and friction angle of concrete at a super early age. However, these two mechanical parameters are necessary to study the influence of engineering vibration on super-early-age concrete. In view of this, the mechanical properties of the super-early age-concrete are investigated in this work by direct shear testing. Firstly, the shear strength of the super-early-age concrete is measured by the direct shear experiment under different normal pressures at different times. Secondly, the cohesion and friction angle of the super early age concrete are calculated according to the Mohr–Coulomb criterion of failure. To overcome the great discreteness and randomness in the measured data, a new robust regression analysis algorithm is presented to replace the traditional regression analysis method to obtain more reliable and reasonable mechanical parameters. According to the experimental and theoretical analysis results, it is found that the friction angles of the super early age concrete are located in the interval of [50°, 70°]. The cohesion of the concrete is about 78.7 kPa at the initial setting state and about 190.9 kPa at the final setting state, respectively. It has been shown that the cohesion of the concrete at a super-early age tends to increase rapidly with time. The method and test results of this work can be used as a reference for relevant engineering practice. Specifically, the proposed regression method can be extended to the data analysis of other mechanical parameters of concrete, as well as other brittle materials such as rock. The test results of early concrete cohesion and friction angle can be used to analyze the adverse effects of vibration on newly cast concrete members in pile driving and blasting engineering.     

乳突后小骨窗开颅骨片复位显微手术切除大型桥小脑角肿瘤

目的 探讨大型桥小脑角肿瘤经乳突后小骨窗开颅、骨片复位的手术方法 及其治疗效果.方法 18例大型桥小脑角肿瘤(听神经鞘瘤13例,脑膜瘤3例,胆脂瘤2例)均采用单侧乳突后小骨窗开颅,应用显微神经外科技术进行肿瘤切除,必要时磨开内听道,术中行脑干听觉诱发电位(BAEP)、体感诱发电位(SEP)和面神经功能监测,肿瘤切除后严密缝合硬脑膜,骨片复位.结果 肿瘤全切除17例、次全切除1例.全组患者的面神经均得到了解剖保留.无手术死亡.术后复查MRI示17例肿瘤全切除者未见有肿瘤残留,1例听神经鞘瘤行次全切除者于内听道内可见少许肿瘤组织残留,术后3个月行伽玛刀治疗.术后有10例遗留轻度面瘫(口角稍有歪斜,眼睑闭合良好),均为大型听神经鞘瘤患者,余患者无脑神经功能障碍,恢复良好.结论乳突后小骨窗开颅术适用于不同大小的桥小脑角肿瘤,严格按显微神经外科技术操作,结合术中BAEP,SEP和面神经功能监测,均可做到肿瘤全切除,并能有效地保护肿瘤周围的重要神经结构及其功能.严密缝合硬脑膜和骨片复位可消除局部皮下积液.     

Influence of Altered Knee Angle on Electromyographic Activity of Hamstring Muscles Between Nordic Hamstring Exercise and Nordic Hamstring Exercise with Incline Slope Lower Leg Board

BackgroundPrevious studies have shown that performing the Nordic hamstring exercise (NHE) with different board slope angles can affect hamstring activation. However, changes in muscle length with different board slopes can alter joint angles leading to the moment arm (MA) at the knee changing during the NHE.PurposeThis study aimed to investigate the influence of changing muscle length on hamstring electromyographic activity during an isometric NHE, while maintaining an equal moment arm.Study DesignA crossover study designMethodsSixteen male volunteers performed two types of conventional NHE, one with knees on the floor (NHE) and one with the legs placed upon an incline slope of a lower leg board (NHEB). To compare between the conventional and inclined NHE, the moment arm at the knee was calculated to be equal by an examiner holding the lower legs at points marked at 77% and 94% of the length of the lower leg. The four sub-groups comprised of: 1) NHE-77%, 2) NHE-94%, 3) NHEB-77%, and 4) NHEB-94%. The hamstring EMG activity was measured at the biceps femoris long head (BFlh) and at the semitendinosus (ST) and related compensatory muscles. The RMS data were normalized as a percentage of the maximum isometric values (normalized EMG [nEMG]). Significant main effects findings were followed up with Tukey’s post-hoc test using SPSS software and statistical significance was set at the p < 0.05 level.ResultsThe BFlh EMG activity values for NHE-77% were significantly higher than those for NHE-94% (p= 0.036) and NHEB-77% (p < 0.001), respectively, while ST during NHE-77% was significantly higher only in NHEB-77% (p < 0.001). In addition, NHEB-94% was significantly greater than NHEB-77% for both BFlh (p < 0.001) and ST (p < 0.001).ConclusionThese results indicate that hamstring electromyographic activity is decreased when the hamstring muscle is lengthened during the Nordic hamstring exercise.Level of Evidence3     

调胃承气颗粒的成型辅料优选

目的:筛选调胃承气颗粒的辅料种类及配比,解决其成型性、溶化性及吸湿性等问题,为该制剂的临床推广与开发提供参考。方法:以颗粒的外观、粒度、水分、溶化性、吸湿性等为质量评价指标,通过单因素试验筛选调胃承气颗粒的辅料品种、配比及用量,并对成型颗粒进行质量验证和临界相对湿度、休止角考察。结果:最佳成型辅料为乳糖和甘露醇混合物,以浸膏-乳糖-甘露醇(1∶3∶1)配比混合制粒,制得的颗粒大小均匀,成型性、溶解性、流动性均好,且不易吸湿。临界相对湿度69%,休止角40度。结论:优选的辅料可显著地提高该制剂的稳定性,且工艺科学合理、简便可行。     

青光眼引流钉植入术治疗难治性开角型青光眼的疗效

目的:观察青光眼引流钉植入术治疗难治性青光眼的疗效.方法:对联合应用抗青光眼药物无法控制的难治性开角型青光眼1 9例19只眼行青光眼引流钉植入术,术中应用丝裂霉素(2 mg/6～8 mL,2.5～4 min)及可松解缝线.术后1天、2周和1、3、6、12个月进行随访,观察眼压、视力、滤过泡形态、前房深度、眼底C/D、降眼压药物使用情况、完全及部分成功率及有无并发症等情况.结果:19例患者中,术后完全成功率78.9％(1 5例),部分成功率10.5％(2例),失败10.5％(2例).术前用3～5种降眼压药,眼压控制于27.7±10.1 mmHg.术后随访仅三人需使用1～2种降压药物.眼压下降组间有显著性意义(P＜0.001).与术前相比,术后1天(11.8±7.7 mmHg,P＜0.001),术后2周(10.1-±4.2 mmHg,P＜0.05),1个月(12.0±4.0 mmHg,P=0.001),6个月(12.2±3.4 mmHg,P＜0.001),1年(13.1±3.3 mmHg,P=0.001)及2年随访(14.5±2.5 mmHg,P=0.001),眼压下降均具有显著性意义.术后患者视力、前房深度及C/D改变差异无显著性意义.末次随访滤过泡弥散隆起57.9％(11例),微囊型15.8％(3例),瘢痕型21.1％(4例),包裹型5.3％(1例).所有患者均未观察到明显的术后并发症的发生.结论:房水引流钉植入术治疗难治性开角型青光眼手术成功率高,并发症少,值得推广.     

转化生长因子β1对体外培养的牛眼小梁细胞MMP3和MMP9表达的影响

目的 探讨转化生长因子β1（TGF-β1）对培养的牛眼小梁细胞基质金属蛋白酶（MMPs)的影响。房水引流阻力在原发性开角型青光眼（POAG）发病机制中的作用。方法 对牛眼小梁细胞进行体外原代及传代培养，对传三代小梁细胞分别施加含TGF-β1终浓度为0、0.5,1,5ng/ml的培养液，48h后行MMP3及MM农艺师免疫组人SP法染色。结果进行计算机图像分析并行统计学检验。结果 体外培养的牛眼小梁细胞表达MMP3及MMP9，TGF-β1可抑制小梁细胞MMP3及MMP9表达。结论 TGF-β1在一定范围内抑制小梁细胞MMP3及MMP9表达，造成小梁网ECM的异常堆积，导致房水引流阻力增高。     

颈胸交界处椎体结核的个性化手术治疗策略

目的探讨颈胸交界处椎体结核个性化手术治疗方法。方法回顾性分析2006年6月-2012年6月收治的16例颈、胸交界处椎体结核,6例采用低位下颈椎前方入路联合胸骨柄劈开术,5例采用右侧前方经肩胛下开胸入路,5例采用单纯经后路入路,行病灶清除、椎体间钛网植入（或植骨）及内固定术治疗。结果16例均获得随访,时间平均2年,患者血红细胞沉降率恢复正常,植骨完全融合,无螺钉松动、脱落及钢板断裂等并发症。术后神经功能恢复按Frankel分级,全部恢复到E级。结核病灶无复发,术后后凸Cobb角较术前明显改善,末次随访后凸Cobb角无明显丢失。结论颈胸交界处椎体结核应根据不同节段椎体及椎体破坏程度选择不同的手术入路及固定方法。     

Oblique Low-Velocity Impact Response and Damage Behavior of Carbon-Epoxy Composite Laminates

The low-velocity impact behavior of carbon-epoxy cross-ply composites was numerically investigated, examining the effect of impact angle. A plastic continuum damage model, introducing the cohesive interface to describe delamination damage, was established and was validated by available experimental data. Impact histories, progressive deformation, stress transfer, and impact damage are respectively discussed. The results show that an increase in impact angle intensifies the action of tangential force, and gradually transfers energy absorption from normal plastic deformation to tangential deformation and friction, which dissipates more energy through relatively longer contact duration and larger impactor displacement. The delamination damage to upper layers is more affected by tangential loads, intensifying with the increase of the impact angle, and the damage area to the top interface is increased by 132.1% from 0° impact to 60° impact. Meanwhile, the delamination damage to lower layers is mainly determined by normal loads, weakening with the increasing impact angle overall, and the damage area of the lowest interface decreases by 36.6% from 0° impact to 60° impact.