中国美利奴（新疆型）新品系羊综合选择指数制定指数制定及应用效果分析

本研究分别对中国美利奴羊（新疆型）体格大品系和毛质好品系制定出综合选择指数I1=1.97x1 3.32x2(x1为体重，x2为毛量）和I2=2.2x1 0.67x2(x1为弯曲评分，x2为毛量），使用效果表明，两个选择指数实用性较为理想。     

中国美利奴羊(新疆军垦型)羊毛长度分析

本文分析了中国美利奴羊 (新疆军垦型 )不同部位、年龄、品系羊毛长度 ,用最小显著极差法(LSR法 )进行多重比较。结果表明 ,不同部位毛长由长到短顺序为肩 >侧 >股 >背 >腹 ,体侧、肩与腹、背有极显著差异 (P <0 .0 1 )。不同年龄羊毛长度从高到低顺序为 1 .5～ 3.5～ 2 .5～ 4 .5～ 5.5～ 6.5～ 7.5岁 ,育成羊羊毛长度明显高于其它年龄羊只 ,2 .5、3.5、4 .5、5.5岁间羊毛长度无显著差异 ,但 2 .5、3.5、4 .5、与 7.5岁间差异极显著 (P <0 .0 1 ) ,.5.5岁与 7.5岁 ,2 .5、3.5与 6.5岁间差异显著 (P <0 .0 5)。A、M、D系间毛长差异不显著 ,但与U、X系间差异极显著 (P <0 .0 1 ) ,U系与X系差异极显著 (P >0 .0 1 )。     

中国美利奴羊（新疆型）新品系羊毛物理性能研究

为系统了解中国美利奴羊（新疆型）毛质好品系（下称毛质系）和体格大品系（下称体大系）毛纤维物理性能，我们于１９９１年和１９９４年分别对巩乃斯种羊场两品系公母羊的毛纤维物理性能，进行了分析研究，如果如下。     

中国美利奴羊(新疆军垦型)多胎品系数量性状遗传力及性状相关分析

本文对中国美利奴羊（新疆军垦型）多胎品系数量性状的遗传力、表型相关进行了初步研究,建立了回归方程,用相关指数对回归方程进行效果分析。此类型的早期性状如断奶体重变异系数大（20.8%）、遗传力高（0.51),与周岁体重（0.7032)、周岁毛量（0.6612)高度正相关（P＜0.010,与周岁体重的相关指数较高（0.4945),断奶重估计周岁体重、周岁毛量效果较好,是早期选择的重要性状,应加强羔羊的培育,以充分发挥其生产潜力。     

中国美利奴羊(新疆型)主要性状生长发育规律

通过分析中国美利奴羊(新疆型)母羊从断乳、1.5岁的体重、羊毛长度、产毛量等性状的生长发育规律，结果表明从断乳到1.5岁期间，体重、毛长发育较快，1．5岁以后，羊毛长度、体重增长趋缓，羊毛弯曲明显程度评分、油汗颜色评分两性状在整个生长发育阶段趋于稳定。     

中国美利奴羊(新疆军垦型)细型、超细型品系主要经济性状及生长发育的研究

紫泥泉种羊场选育的中国美利奴羊 (新疆军垦型 )细型、超细型品系羊体重 (41.6 3kg)、毛密度 (6 52 7根 /cm2 )、净毛率 (59.0 5% )等经济性状分别与非品系 (46 .0 7kg、5870根 /cm2 、6 1.53% )比较差异不显著 (P >0 .0 5) ,细度性状 (18.6 1μm)与非品系 (2 1.2 0 μm)比较差异极显著 (P <0 .0 1)。体尺与非品系比较差异不显著 ,符合中国美利奴羊标准     

近交在中国美利奴羊(新疆军垦型)细型、超细型品系培育中的应用

品系群体近交系数为 11.76 % ,三个世代近交增长速度分别为 1.8%、2 .5%、0 .91%。近交系数在控制强度以下 ,但一、二世代近交强度过高     

中国美利奴羊(新疆军垦型)细型、超细型品系主要遗传参数的估测

品系主要经济性状随着羊毛纤维直径减小均呈现不同程度下降趋势。遗传力除断奶毛长为低遗传力 ,其它性状为中、高遗传力 ;在表型相关上 ,羊毛纤维直径与初生重为正相关 ,与其它性状为负相关 ;在遗传相关上 ,羊毛纤维直径与其它性状间都为负相关     

中国美利奴羊(新疆型)肉用类型部分经济性状的遗传分析

采用巩乃斯种羊场中国美利奴羊（新疆型）肉用类型1995年4月—2001年4月周岁母羊生产性状的鉴定成绩和同年的剪毛测定结果。根据半同胞遗传协方差，对其部分生产性状的遗传规律做了分析。结果是剪毛后体重、剪毛量、毛长、目测羊毛细度遗传力分别为0．519、0．416、0．466、0．325。通过相关分析揭示了剪毛后体重、剪毛量、毛长、目测羊毛细度之间的表型相关与遗传相关。     

健身气功·八段锦对社区2型糖尿病伴抑郁患者抑郁症状及生活质量的影响

目的:评价健身气功.八段锦对社区2型糖尿病(T2 DM)伴抑郁患者抑郁症状与生活质量的影响。方法:随机抽取北京市社区297例T2 DM患者,运用抑郁自评量表(SDS)筛查其中伴发抑郁症状者;再将69例T2 DM伴抑郁症状的患者随机分为八段锦组(n=33)和社区护理组(n=36)。八段锦组在接受社区健康教育的基础上,规律练习健身气功.八段锦,每周练习3～5天,每次练习2遍,2遍之间休息2min,连同准备活动和整理运动,一次练习在40min左右,每周集中练习1次。社区护理组仅接受社区健康教育。研究周期均为12周。分别在干预前、干预第6周和第12周,应用自评抑郁量表(SDS)和2型糖尿病人生活质量量表(DMQLS)评价两组患者抑郁症状和生活质量,并抽取静脉血检测糖化血红蛋白(HbA1c)。结果:八段锦组干预后第6周和第12周时SDS均值较干预前降低(P<0.05),社区护理组干预前后差异无统计学意义(P>0.05),八段锦组第12周SDS均值低于社区护理组(P<0.05)。八段锦组第12周DMQLS总分均值及心理维度、满意度维度均值低于社区护理组(P<0.05)。八段锦组第12周HbA1c均值低于社区护理组(P<0.05)。结论:长期规律练习健身气功.八段锦可有效改善T2 DM伴抑郁患者的抑郁症状,提高其生活质量,尤其是在心理维度和满意度维度方面,并可帮助患者稳定血糖水平。     

Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT

Objective

To test the effects of heart rate, body mass index (BMI) and noise level on interscan and interobserver variability of coronary artery calcium (CAC) scoring on a prospective electrocardiogram (ECG)-triggered 64-slice CT.

Materials and Methods

One hundred and ten patients (76 patients with CAC) were scanned twice on prospective ECG-triggered scans. The scan parameters included 120 kV, 82 mAs, a 2.5 mm thickness, and an acquisition center at 45% of the RR interval. The interscan and interobserver variability on the CAC scores (Agatston, volume, and mass) was calculated. The factors affecting the variability were determined by plotting it against heart rate, BMI, and noise level (defined as the standard deviation: SD).

Results

The estimated effective dose was 1.5 ± 0.2 mSv. The mean heart rate was 63 ± 12 bpm (range, 44-101 bpm). The patient BMIs were 24.5 ± 4.5 kg/m² (range, 15.5-42.3 kg/m²). The mean and median interscan variabilities were 11% and 6%, respectively by volume, and 11% and 6%, respectively, by mass. Moreover, the mean and median of the algorithms were lower than the Agatston algorithm (16% and 9%, respectively). The mean and median interobserver variability was 10% and 4%, respectively (average of algorithms). The mean noise levels were 15 ± 4 Hounsfield unit (HU) (range, 8-25 HU). The interscan and interobserver variability was not correlated with heart rate, BMI, or noise level.

Conclusion

The interscan and interobserver variability of CAC on a prospective ECG-triggered 64-slice CT with high image quality and 45% of RR acquisition is not significantly affected by heart rate, BMI, or noise level. The volume or mass algorithms show reduced interscan variability compared to the Agatston scoring (p < 0.05).     

The impact of technical conditions of X-ray imaging on reproducibility and precision of digital computer-assisted X-ray radiogrammetry (DXR)

Objective To evaluate the reproducibility of imaging and analysis for bone mineral density (BMD) determination using digital computer-assisted X-ray radiogrammetry (DXR; Pronosco X-posure, version V.2, Sectra Pronosco, Denmark); to verify potential factors that influence BMD extrapolation such as tube voltage, film-focus distance (FFD), film quality and brand (Kodak T-MAT-Plus, Konika SRH, Agfa Scopix), imaging technology (conventional, digital), imaging system (Kodak, Agfa) and exposure level (mAs); and to clarify whether DXR analysis based on printouts of digital images is comparable to analysis of conventional images.Design and patients The hand of a cadaver was X-rayed using varied parameters: 4–8 mAs, 40–52 kV, 90–130 cm FFD. Radiographs under standardised conditions were performed 10 times using a conventional machine (Philips Super 80 CP) and the printouts of a digital system (Digital Diagnost Philips Optimus) for the analysis of reproducibility. One image was scanned and analysed 10 times additionally for imaging reproducibility.Results Reliability error of the system for the imaging process using conventional radiographs-rays was 0.49% (standard conditions: 6 mAs, 40 kV, 1 m FFD), using printouts of digital images was 2.89% (4 mAs, 42 kV, 1 m FFD) and regarding the analysis process was 0.22%. BMD calculation is not affected by alterations in FFD (precision error 1.21%), mAs (0.83%) or film quality/brand (0.38%), but differs significantly depending on tube voltage (2.70%). The system was not able to analyse conventional images with tube voltages of 49/52 kV.Conclusion DXR technology is stable with most of the tested parameters. Normative data should exclusively be used for calculations using similar tube voltage or correction factors. All other parameters had no significant influence on the BMD calculation. Reproducibility is high. For technical reasons it is not recommended to use the printouts of digital images for BMD determination.     

Effect of Electromagnetic Pulses (EMP) on associative learning in mice and a preliminary study of mechanism

Abstract

Purpose: To investigate the effects of electromagnetic pulses (EMP) on associative learning in mice and test a preliminary mechanism for these effects.

Materials and methods: A tapered parallel plate gigahertz transverse electromagnetic (GTEM) cell with a flared rectangular coaxial transmission line was used to expose male BALB/c mice to EMP (peak-intensity 400 kV/m, rise-time 10 ns, pulse-width 350 ns, 0.5 Hz and total 200 pulses). Concurrent sham-exposed mice were used as a control. Associative learning, oxidative stress in the brain, serum chemistry and the protective action of tocopherol monoglucoside (TMG) in mice were measured, respectively.

Results: (1) Twelve hour and 1 day post EMP exposure associative learning was reduced significantly compared with sham control (p < 0.05) but recovered at 2 d post EMP exposure. (2) Compared with the sham control, lipid peroxidation of brain tissue and chemiluminescence (CL) intensity increased significantly (p < 0.05), while the activity of the antioxidant enzymes Superoxide Dismutase [SOD], Glutathione [GSH], Glutathione Peroxidase [GSH-Px], Catalase [CAT]) decreased significantly (p < 0.05) at 3 h, 6 h, 12 h and 1 d post EMP exposure. All these parameters recovered at 2 d post EMP exposure. (3) No significant differences between the sham control group and EMP exposed group were observed in serum cholesterol and triglycerides. (4) Pretreatment of mice with TMG showed protective effects to EMP exposure.

Conclusions: EMP exposure significantly decreased associative learning in mice and TMG acted as an effective protective agent from EMP exposure. This mechanism could involve an increase of oxidative stress in brain by EMP exposure.     

Frequency data for the STR loci HumFibra (FGA) and HumACTBP2 (SE33) in a population of Germans and Turks from South-West Germany

Population studies were carried out on German and Turkish individuals from South-West Germany using the short tandem repeat (STR) systems HumFibra (n = 138 Turkish and 1161 German individuals) and HumACTBP2 (n = 202 Turkish and 1338 German individuals). After electrophoresis 19 alleles could be identified for HumFibra and 55 for HumACTBP2. No significant deviations from Hardy-Weinberg equilibrium were observed. Received: 11 February 1998 / Received in revised form: 4 May 1998     

Breath-Hold Projection Magnetic Resonance-Cholangio-Pancreaticography (MRCP): a New Method for the Examination of the Bile and Pancreatic Ducts

Breath-hold MR cholangio-pancreaticography using the RARE method was evaluated as a noninvasive alternative to direct cholangio-pancreaticography in 30 healthy volunteers and in 30 patients with various diseases of the respective duct systems. In contrast to 3D MR cholangiography, RARE MRCP generates projection images requiring a 4-s acquisition time and no postprocessing. Diagnostic information gained from the cholangio-pancreaticograms was fully equivalent to that of conventional x-ray imaging by invasive procedures. Additional information was gained whenever endoscopic access was impossible and/or cystic malformations were present.     

Estimation and comparison of effective dose (E) in standard chest CT by organ dose measurements and dose-length-product methods and assessment of the influence of CT tube potential (energy dependency) on effective dose in a dual-source CT

Purpose

To determine effective dose (E) during standard chest CT using an organ dose-based and a dose-length-product-based (DLP) approach for four different scan protocols including high-pitch and dual-energy in a dual-source CT scanner of the second generation.

Materials and methods

Organ doses were measured with thermo luminescence dosimeters (TLD) in an anthropomorphic male adult phantom. Further, DLP-based dose estimates were performed by using the standard 0.014 mSv/mGycm conversion coefficient k. Examinations were performed on a dual-source CT system (Somatom Definition Flash, Siemens). Four scan protocols were investigated: (1) single-source 120 kV, (2) single-source 100 kV, (3) high-pitch 120 kV, and (4) dual-energy with 100/Sn140 kV with equivalent CTDIvol and no automated tube current modulation. E was then determined following recommendations of ICRP publication 103 and 60 and specific k values were derived.

Results

DLP-based estimates differed by 4.5–16.56% and 5.2–15.8% relatively to ICRP 60 and 103, respectively. The derived k factors calculated from TLD measurements were 0.0148, 0.015, 0.0166, and 0.0148 for protocol 1, 2, 3 and 4, respectively. Effective dose estimations by ICRP 103 and 60 for single-energy and dual-energy protocols show a difference of less than 0.04 mSv.

Conclusion

Estimates of E based on DLP work equally well for single-energy, high-pitch and dual-energy CT examinations. The tube potential definitely affects effective dose in a substantial way. Effective dose estimations by ICRP 103 and 60 for both single-energy and dual-energy examinations differ not more than 0.04 mSv.     

Hydroxyl Radical-induced Strand Break Formation of Poly(U) in Anoxic Solution. Effect of Dithiothreitol and Tetranitromethane

Summary

The role of dithiothreitol (DTT) and tetranitromethane (TNM) on the yields of radiation-induced strand break formation in polyuridylic acid (poly(U)) was studied in anoxic aqueous solutions at neutral pH by low-angle laser light-scattering. From G (single-strand breaks) as a function of DTT concentration it follows that two different processes lead to OH radical-induced single-strand break (ssb) formation. Only one of the two processes, which accounts for 80 per cent of the ssb formation, is inhibited by DTT, the other one, 20 per cent, is not inhibited. The ‘repair’ process is attributed to H-donation to the C-6-yl radical of the uracil moiety. The C-6-yl radical is produced by OH addition to the C-5 position of the uracil moiety. It follows that the sugar radicals, in contrast to earlier suggestions, do not seem to be repaired by DTT at the low concentrations used. The strand break formation not inhibited by DTT is induced by radicals other than the uracil-6-yl radical, e.g. the uracil-5-yl or the OH radicals reacting with the sugar moiety. The strong reduction of G(ssb) from 2·3 to 0·2 on addition of TNM is also discussed.