B超监测梅花鹿性控精液腹腔镜输精试验

梅花鹿常规冻精与性控冻精解冻后进行品质鉴定,结合B超监测卵泡有选择的对60只同期发情处理的梅花鹿进行腹腔镜精准输精。数据分析显示,同期发情处理后梅花鹿卵巢B超监测结果与腹腔镜输精受胎率存在明显的正相关;X和Y型冻精产仔率为83.33%,而常规冻精产仔率为65.31%,X、Y型冻精与常规冻精组间差异显著(P<0.05);常规冻精组、X冻精组与Y冻精组所产后代性别比(公/母)分别为9:8、0:10和16:1,X、Y型冻精与常规冻精组间差异显著(P<0.05),X、Y型冻精与常规冻精所产后代出生及60 d时的体重差异不显著(P <0.05)。结果表明,结合B超监测有选择的进行梅花鹿性控精液腹腔镜人工输精,可显著提高受胎率,降低成本,技术可行。

深过冷Co-B合金外源触发形核行为及组织研究

合金的形核机制及其控制方法是凝固理论的重要研究领域之一。触发形核方式可自主控制形核过冷度,对研究形核理论及组织演变具有极大帮助。但熔体具有亚稳性,在实际处理时,外源性杂质引入熔体后将作为触发形核异质点,改变过冷度ΔT和再辉度ΔT_(R),显著影响后续凝固行为,该种现象更为普遍。本文通过玻璃包覆结合循环过热过冷方式,获得两类不同形核模式凝固的Co_(80)B_(20)合金。自发形核模式下,ΔT及ΔT_(R)分别为280和199 K,组织组成为Co/Co_(3)B细小规则共晶。外源性触发形核模式下,ΔT和ΔT_(R)降至122和21 K。组织转变为初生Co枝晶及晶间的Co_(23)B_(6)基体相。外源性杂质将降低f(θ),减小临界形核半径,降低ΔT,使得组织更加不均匀,在实际的熔体处理过程中应予以控制。

Responsive mechanism and coordination mode effect of a bipyridine-based two-photon fluorescent probe for zinc ion

The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.

B族溶血性链球菌带菌孕妇不同分娩方式对新生儿感染的影响及相关影响因素分析

目的探讨B族溶血性链球菌(GBS)带菌孕妇不同分娩方式对新生儿感染的影响及相关影响因素分析。方法分析2017年1月至2018年12月在首都医科大学附属北京妇产医院产检并分娩的1376例妊娠足月GBS带菌孕妇的临床资料。根据分娩方式不同分为阴道分娩组及剖宫产组,按照新生儿的感染情况将其分为GBS阳性组和GBS阴性组。分析不同分娩方式下新生儿GBS感染情况及其影响因素。结果经阴道分娩孕妇999例,新生儿999例;剖宫产孕妇377例,新生儿388例。阴道分娩组中新生儿GBS阳性79例,剖宫产组新生儿GBS阳性12例;两组新生儿感染情况比较,差异有统计学意义(P<0.05)。两组年龄、分娩孕龄、胎膜早破占比比较,差异无统计学意义(P>0.05);两组使用抗生素治疗占比比较,差异有统计学意义(P<0.05)。产钳助产及自然分娩,使用青霉素和头孢唑啉是新生儿GBS感染的影响因素(P<0.05)。结论妊娠晚期携带GBS的孕妇不同的分娩方式与新生儿GBS感染相关,产前使用抗生素可以降低新生儿GBS感染率。

床旁B超动态定位技术在极早产儿PICC中的应用

目的:探讨床旁B超动态定位技术在极早产儿经外周静脉置入中心静脉导管(PICC)中的应用价值。方法:选取新生儿重症监护室(NICU)住院期间拟留置PICC的极早产儿160例,其中的80例作为对照组,采用盲穿置管方法+常规护理,其余的80例作为干预组,采用超声引导置管、床旁B超动态定位监测+常规护理。比较两组PICC导管的继发性异位率、人工矫正率、重新置管率。结果:干预组PICC导管继发性异位率、重新置管率均低于对照组,差异有统计学意义(P<0.05)。干预组人工矫正率高于对照组(P<0.05)。结论:床旁B超动态定位技术能有效降低极早产儿PICC导管继发性异位率,提高人工矫正成功率。

基于四苯乙烯-罗丹明B的新型比色Fe^(3+)荧光探针的合成及其性能研究

文章利用2,6-吡啶二甲酰氯“一锅”两步连接四苯基乙烯和罗丹明B两大荧光母体,合成了一种新型比色Fe^(3+)荧光探针L,并对其进行结构表征和性能研究。利用紫外-可见吸收法和分子荧光光谱法研究了L的光学性质,实验结果表明:当Fe^(3+)存在时,探针溶液显示出从无色到橘红色的颜色明显变化和显著的荧光变化。该探针在水溶液中对Fe^(3+)表现出较高选择性和灵敏度,并且具有良好的线性响应范围(30~200μmol/L)和低检测限(5.03×10-6 mol/L),同时还能对Cu^(2+)实现可视化识别。通过ESI-MS研究表明L与Fe^(3+)可1∶1进行络合,导致罗丹明B螺内酰胺诱导开环,引起变色,聚集状态减弱,从而达到选择性识别Fe^(3+).

Spatial Evolution Study of EEDFs and Plasma Parameters in RF Stochastic Regime by Langmuir Probe

An RF compensated cylindrical Langmuir probe system has been developed and used to characterize an RF capacitive two temperature plasma discharge in a stochastic mode. The novelty of the work presented here is the use of the driven electrode （cathode） without ground shield. Measurements of the electron energy distribution function （EEDF） and plasma parameters were achieved under the following conditions： 50 W of RF power and 5× 10-2 mbar of argon pressure. The probe measurements are performed at 3 cm above the electrode and the probe was shifted radially （r direction） from the center （r = 0 cm） of the inter-electrodes region towards the chamber wall （R = 10.75 cm）. The results show that the EEDF is bi-Maxwellian and its shape remains the same through the scanned region. The farther the probe from the central region, the lower the EEDF maximum. The plasma density is observed to decrease according to a Gaussian profile along the radial direction and falls to 50% of its maximum when close to the cathode edge （r = 5.5 cm）. At the same time the effective electron temperature remains constant for r〈4 cm and increases for r≥4 cm. The high-temperature and low-temperature electrons＇ densities and temperatures are also discussed in the article.

Intrinsic relationship of vorticity between modes A and B in the wake of a bluff body

The intrinsic physical relationship of vorticity between modes A and B in the three-dimensional wake transition is investigated.Direct numerical simulations for the flow past a square-section cylinder are carried out at Reynolds numbers of 180 and 250,associated with modes A and B,respectively.Based on the analysis of spacial distributions of vorticity in the near wake,characteristics of the vertical vorticity in modes A and B are identified.Moreover,the relationship of three vorticity components with specific signs is summarized into two sign laws,as intrinsic physical relationships between two instability modes.By the theory of vortex-induced vortex,such two sign laws confirm that there are two and only two kinds of vortex-shedding patterns in the near wake,just corresponding to modes A and B.In brief,along the free stream direction,mode A can be described by the parallel shedding vertical vortices with the same sign,while mode B is described by the parallel shedding streamwise vortices with the same sign.Finally,it is found out that the|-type vortex is a basic kind of vortex structure in both modes A and B.

Axial profiles of argon helicon plasma by optical emission spectroscope and Langmuir probe

We present the axial profiles of argon helicon plasma measured by a local optical emission spectroscope(OES) and Langmuir RF-compensated probe. The results show that the emission intensity of the argon atom lines(750 nm, 811 nm) is proportional to the plasma density determined by the Langmuir probe. The axial profile of helicon plasma depends on the discharge mode which changes with the RF power. Excited by helical antenna, the axial distribution of plasma density is similar to that of the external magnetic field in the capacitive coupled mode(E-mode). As the discharge mode changes into the inductively coupled mode(H-mode), the axial distribution of plasma density in the downstream can still be similar to that of the external magnetic field, but becomes more uniform in the upstream. When the discharge entered wave coupled mode(W-mode), the plasma becomes nearly uniform along the axis, showing a completely different profile from the magnetic field. The W-mode is expected to be a mixed pattern of helicon(H) and Trivelpiece-Gould(TG) waves.

腹部B型超声脂肪肝声像阳性体检人群人体成分、血脂水平分析

目的 分析腹部B型超声脂肪肝声像阳性(脂肪肝)体检人群人体成分、血脂水平变化,比较不同内脏脂肪面积体检者的脂肪肝检出率,并探讨体检人群人体成分分析与血脂检测的临床意义。方法 将230名自愿进行人体成分测定的体检者(均行腹部B型超声检测)作为研究对象,其中脂肪肝患者83人(脂肪肝组),非脂肪肝患者(腹部B型超声脂肪肝声像阴性)147人(非脂肪肝组)。对比两组研究对象的人体成分、血脂水平,并比较不同内脏脂肪面积研究对象的脂肪肝检出率。结果 脂肪肝组内脏脂肪面积、体重、体质量指数、腰臀比、肌肉量、去脂体重、骨骼肌重量、体脂肪重量、体脂百分比、四肢脂肪重量、躯干脂肪重量、腰围均较非脂肪肝组大或高,总胆固醇、甘油三酯、低密度脂蛋白胆固醇、载脂蛋白B水平均较非脂肪肝组高,高密度脂蛋白胆固醇、载脂蛋白AI水平、载脂蛋白AI/载脂蛋白B均较非脂肪肝组低,差异均有统计学意义(均P<0.05)。内脏脂肪面积<80 cm^(2)、80~100 cm^(2)和≥100 cm^(2)三组研究对象,其脂肪肝的检出率分别为21.32%(29/136)、58.82%(20/34)、56.67%(34/60),差异有统计学意义(χ^(2)=31.490,P<0.001)。结论 有脂肪肝的体检人群人体成分和血脂水平与无脂肪肝的体检人群有差异。对人体成分和血脂水平的异常者提出警告,改变其饮食结构和生活习惯,或可预防脂肪肝的发生。

Detection of hepatitis B virus DNA by real-time PCR using TaqMan-MGB probe technology

AIM: To develop a real-time PCR for detecting hepatitis B virus-(HBV) DNA based on TaqMan technology using a new MGB probe.METHODS: Plasmid containing the sequence of X gene (1414-1744 nt) was constructed as HBV-DNA standard for quantitative analysis. A TaqMan-MGB probe between primers for amplification was designed to detect PCR products. The interested sequence contained in the plasmid and in clinical specimens was quantitatively measured.RESULTS: The detection limit of the assay for HBV DNA was 1 genome equivalent per reaction. A linear standard curve was obtained between 100 and 109 DNA copies/reaction (r＞0.990). None of the negative control samples showed false-positive reactions in duplicate. HBV DNA was detected in 100% (50/50) of HBV patients with HbeAg, and in 72.0% (36/50) with HBsAg, HBeAb and HBcAb. The coefficient of variation for both intra- and inter-experimental variability demonstrated high reproducibility and accuracy.CONCLUSION: Real-time PCR based on TaqMan-MGB probe technology is an excellent method for detection of HBV DNA.

Phonon Confinement Effect in Two-dimensional Nanocrystallites of Monolayer MoS_2 to Probe Phonon Dispersion Trends Away from Brillouin-Zone Center

The fundamental momentum conservation requirement q - 0 for the Raman process is relaxed in the nanocrystal- lites （NCs）, and phonons away from the Brillouin-zone center will be involved in the Raman scattering, which is well-known as the phonon confinement effect in NCs. This usually gives a downshift and asymmetric broadening of the Raman peak in various NCs. Recently, the A1 mode of 1L MoS2 NCs is found to exhibit a blue shift and asymmetric broadening toward the high-frequency side [Chem. Soc. Rev. 44 （2015） 2757 and Phys. Rev. B 91 （2015） 195411]. In this work, we carefully check this issue by studying Raman spectra of lL MoS2 NCs prepared by the ion implantation technique in a wide range of ion-implanted dosage. The same confinement coefficient is used for both E＇ and A＇1 modes in 1L MoS2 NCs since the phonon uncertainty in an NC is mainly determined by its domain size. The asymmetrical broadening near the A＇1 and E＇ modes is attributed to the appearance of defect-activated phonons at the zone edge and the intrinsic asymmetrical broadening of the two modes, where the anisotropy of phonon dispersion curves along Г-K and Г- M is also considered. The photoluminescence spectra confirm the formation of small domain size of 1L MoS2 nanocrystallites in the ion-implanted 1L MoS2. This study provides not only an approach to quickly probe phonon dispersion trends of 2D materials away from Г by the Raman scattering of the corresponding NCs, but also a reference to completely understand the confinement effect of different modes in various nanomaterials.

Effect of variable heat treatment modes on microstructures of Fe-Cr-Bcast iron alloy

The effect of heat treatment mode on the microstructure of Fe-Cr-B cast iron alloys was investigated inthis paper by comparing the difference of precipitation patterns of secondary particles after thermal cycling treatment(TCT) with those after normal heat treatment (NHT). No obvious differences were found in precipitation patterns ofsecondary particles between TCT and NHT when experimental temperature was below Ar1. However, whentemperature was over Ar1, there were significant differences, with secondary particles prominently segregated at thegrain boundaries under TCT, while the particles evenly distributed in the matrix under NHT. The reason for themicrostructure differences could be associated with the development of non-equilibrium segregation of boron duringTCT.

Spatial variation behaviors of argon inductively coupled plasma during discharge mode transition

A Langmuir probe and an ICCD are employed to study the discharge mode transition in Ar inductively coupled plasma. Electron density and plasma emission intensity are measured during the E （capacitive discharge） to H （inductive discharge） mode transitions at different pressures. It is found that plasma exists with a low electron density and a weak emission intensity in the E mode, while it has a high electron density and a strong emission intensity in the H mode. Meanwhile, the plasma emission intensity spatial （2D an asymmetric profile in the E mode. Moreover, the at high pressure, but increase almost continuously at image） profile is symmetrical in the H mode, but the 2D image is electron density and emission intensity jump up discontinuously the E to H mode transition under low pressure.

Detection of HBV and HCV Coinfection by TEM with Au Nanoparticle Gene Probes

Gold（Au） nanoparticle HBV DNA or HCV cDNA gene probes were prepared and were used to detect HBV DNA and HCV RNA extracted from positive serum of patients with HBV and HCV coinfection directly by transmission electron microscopy （TEM）. PCR identifying HBV and HCV in serum of patients with HBV and HCV coinfection was established. Alkanethiol-modified oligonucleotide was bound with self-made Au nanoparticles to form nanoparticle HBV DNA or HCV cDNA gene probes through covalent binding of Au-S. HBV DNA and HCV RNA extracted from positive serum of patients with HBV and HCV coinfection was added to the detection system composed of nanoparticle HBV DNA and（or） HCV cDNA gene probes, The results showed that HBV DNA and HCV RNA could be specifically amplified by PCR. The zones of DNA amplification appeared in 431 bp and 323 bp respectively. When HBV DNA and HCV RNA extracted from positive serum of patients with HBV and HCV coinfection were added to the detection system, TEM displayed the nanoparticles self-assembled into large network aggregates. It was concluded that the detection of HBV and HCV coinfection by TEM was convenient and efficient with high specificity and sensitivity.

Design and first result of combined Langmuir-magnetic probe on J-TEXT tokamak

In order to measure boundary electrostatic and magnetic fluctuations simultaneously,a combined Langmuir-magnetic probe(CLMP)has been designed and built on joint-Texas experimental tokamak.The probe consists of 8 graphite probe pins and a 3D magnetic probe,driven by a mechanical pneumatic device.By means of simulation,the shielding effect of the graphite sleeve on the magnetic fluctuation signal is explored,and the influence of the eddy current was reduced by cutting the graphite sleeve.In the experiment,it has been verified that the mutual inductance of electromagnetic signals can be ignored,and a 70–90 k Hz electromagnetic mode is observed around the last closed magnetic surface.The establishment of CLMP provides data for the exploration of the coupling of electrostatic and magnetic fluctuations.

A B-spline active contour model based on finite element method

A B-spline active contour model based on finite element method is presented, into which the advantages of a B-spline active contour attributing to its fewer parameters and its smoothness is built accompanied with reduced computational complexity and better numerical stability resulted from the finite element method. In this model, a cubic B-spline segment is taken as an element, and the finite element method is adopted to solve the energy minimization problem of the B-spline active contour, thus to implement image segmentation. Experiment results verify that this method is efficient for B-spline active contour, which attains stable, accurate and faster convergence.

基于Ti_(3)C_(2)量子点@罗丹明B荧光探针对Cr(Ⅵ)的传感检测研究

采用刻蚀和水热法合成了碳化钛量子点(Ti_(3)C_(2) QDs),该量子点与罗丹明B(RhB)之间由于静电作用产生荧光共振能量转移(FRET)形成荧光探针,Cr(Ⅵ)的内滤效应(IFE)导致探针荧光猝灭,构建了一种“开-关”型荧光探针用于Cr(Ⅵ)的传感检测.在优化实验条件下,该荧光探针对Cr(Ⅵ)的线性响应范围为0.05-500μmol/L,检出限为0.014μmol/L (S/N=3).构建的荧光探针具有制备简单、稳定性和选择性好,对Cr(Ⅵ)的检测灵敏度高等特点,对环境水样中Cr(Ⅵ)测定的回收率为94.3%-104.0%.研究为水体中重金属离子Cr(Ⅵ)的快速和准确测定提供了一种新方法.

Low-frequency vibrational modes of glutamine

High-resolution terahertz absorption and Raman spectra of glutamine in the frequency region 0.2 THz-2.8 THz are obtained by using THz time domain spectroscopy and low-frequency Raman spectroscopy. Based on the experimental and the computational results, the vibration modes corresponding to the terahertz absorption and Raman scatting peaks are assigned and further verified by the theoretical calculations. Spectral investigation of the periodic structure of glutamine based on the sophisticated hybrid density functional B3LYP indicates that the vibrational modes come mainly from the inter-molecular hydrogen bond in this frequency region.

A Study on the Temperature Correlation of B-mode Ultrasonic Image Gray for Noninvasive Temperature Monitoring in Hyperthermia

This paper deals with the temperature correlation of gray scale of B-mode ultrasound image from heated tissue. In this study, many in-vitro fresh pig livers are heated in a temperature range from 28 ℃ to 45℃, from which a series of B-mode ultrasonic images of livers were obtained. The gray-value is evaluated from the ultrasound images respectively. A correlation of the mean gray value of the selected regions (12×12 pixels) in B-mode ultrasonic images of liver and its temperature was pointed out. And the experiment results agreed the evaluation well. And it is possible to monitor the tissue temperature changing in hyperthermia using this correlation.