90例先天性心脏病非侵入性诊断与手术结果比较

二维和多普勒超声心动图检查９０例先天性心脏病患儿，并与手术结果对照。结果与手术诊断的符合率分别为ＶＳＤ９７．８％，ＰＤＡ９６％，ＡＳＤ１００％。本组病例中８例有合并畸形，其中３例误诊。因此，超声心动图检查时应注意合并畸形的诊断。     

Repeated post-exercise administration with a mixture of leucine and glucose alters the plasma amino acid profile in Standardbred trotters

Background

The branched chain amino acid leucine is a potent stimulator of insulin secretion. Used in combination with glucose it can increase the insulin response and the post exercise re-synthesis of glycogen in man. Decreased plasma amino acid concentrations have been reported after intravenous or per oral administration of leucine in man as well as after a single per oral dose in horses. In man, a negative correlation between the insulin response and the concentrations of isoleucine, valine and methionine have been shown but results from horses are lacking. This study aims to determine the effect of repeated per oral administration with a mixture of glucose and leucine on the free amino acid profile and the insulin response in horses after glycogen-depleting exercise.

Methods

In a crossover design, after a glycogen depleting exercise, twelve Standardbred trotters received either repeated oral boluses of glucose, 1 g/kg body weight (BW) at 0, 2 and 4 h with addition of leucine 0.1 g/kg BW at 0 and 4 h (GLU+LEU), or repeated boluses of water at 0, 2 and 4 h (CON). Blood samples for analysis of glucose, insulin and amino acid concentrations were collected prior to exercise and over a 6 h post-exercise period. A mixed model approach was used for the statistical analyses.

Results

Plasma leucine, isoleucine, valine, tyrosine and phenylalanine concentrations increased after exercise. Post-exercise serum glucose and plasma insulin response were significantly higher in the GLU+LEU treatment compared to the CON treatment. Plasma leucine concentrations increased after supplementation. During the post-exercise period isoleucine, valine and methionine concentrations decreased in both treatments but were significantly lower in the GLU+LEU treatment. There was no correlation between the insulin response and the response in plasma leucine, isoleucine, valine and methionine.

Conclusions

Repeated post-exercise administration with a mixture of leucine and glucose caused a marked insulin response and altered the plasma amino acid profile in horses in a similar manner as described in man. However, the decreases seen in plasma amino acids in horses seem to be related more to an effect of leucine and not to the insulin response as seen in man.     

In Vitro Fertilization (IVF) in Straws and a Short Gamete Coincubation Time Improves the Efficiency of Porcine IVF

The present study was designed to evaluate three different in vitro fertilization (IVF) systems: a straw‐IVF system with 10 min of coincubation, a straw‐IVF system with 6‐h coincubation and the microdrop‐IVF system with 6‐h coincubation (the traditional IVF system used routinely in most of IVF laboratories) in an attempt to reduce polyspermic penetration ( Experiment 1 ). When the straw‐IVF system was tested in combination with two coincubation times, the use of 10 min of coincubation significantly increased (p < 0.001) the penetration rate and the efficiency of fertilization (67.7 ± 6.4% vs 31.9 ± 6.5% and 41.5 ± 2.5% vs 17.6 ± 2.5% for 10 min and 6 h, respectively), while there were no significant differences in the incidence of monospermy between both systems (64.3 ± 5.1% and 67.7 ± 3.4%, for 10 min and 6 h, respectively). The penetration rate in the 6‐h microdrop‐IVF system was higher (93.8 ± 3.6%; p < 0.001) compared with the 10‐min straw‐IVF system (67.7 ± 6.4%), however, monospermy was severely reduced (25.0 ± 4.3% vs 67.7 ± 3.4%, for the 6‐h microdrop‐IVF system and 10‐min straw‐IVF system, respectively). The efficiency of the IVF showed similar values between microdrop and 6‐h straw‐IVF systems, but efficiency was significantly improved (p < 0.05) when the 10‐min straw‐IVF system was used. Experiment 2 was designed to compare porcine in vitro embryo production in two IVF systems, the 6‐h microdrop‐IVF system (1000 sperm per oocyte) and 10‐min straw‐IVF system (30 000 sperm per oocyte). The blastocyst formation rates tended (p = 0.06) to be higher when the 10‐min straw‐IVF system was used compared with the 6‐h microdrop‐IVF system. In addition, the number of total cells per blastocyst increased significantly (p < 0.05) in the 10‐min straw‐IVF system. These results showed that the 10‐min straw‐IVF system is an effective way to decrease polyspermic penetration, and improve the efficiency of fertilization and the quality of blastocysts in terms of cell number per embryo.     

绿叶菜菊花脑无公害高产栽培技术

菊花脑属菊科菊属,多年生宿根性草本植物,又名菊花叶、路边黄、黄菊仔,其嫩茎、嫩叶可沙食或作汤,香味浓郁,风味独特,具菊花香气,有清凉解暑、保健等作用,深得市民喜爱,在盐阜地区已有种植,菜农增收显著,具有广泛的推广价值。现将其主要栽培技术介绍如下:     

Effects of carbon nanotubes on morphological structure, thermal and flammability properties of electrospun composite fibers consisting of lauric acid and polyamide 6 as thermal energy storage materials

The ultrafine composite fibers consisting of lauric acid (LA) and polyamide 6 (PA6) as form-stable phase change materials (PCMs), were prepared successfully by electrospinning. The effect of carbon nanotubes (CNTs) on the structural morphology, phase change behaviors, thermal stability, flammability and thermal conductivity properties of electrospun LA/PA6 composite fibers was investigated by field-emission scanning electron microscopy (FE-SEM), differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), microscale combustion calorimeter (MCC) and melting/freezing times measurements, respectively. SEM observations indicated that the LA/PA6 and LA/PA6/CNTs composite fibers possessed flat and ribbon-shaped morphologies, but the neat PA6 fibers had cylindrical shape with smooth surface; and the average fiber diameters for LA/PA6 composite fibers decreased generally with the addition of CNTs. DSC measurements indicated that the heat enthalpies of the composite fibers were lower that that of neat LA powders, while the amounts of CNTs had no appreciable effect on the phase change temperatures and heat enthalpies of the composite fibers. TGA results showed that the addition of CNTs increased the onset thermal degradation temperature, maximum weight loss temperature and charred residue at 700 °C of the composite fibers, attributed to the improved thermal stability properties. It could be found from MCC tests that there were two-step combustion processes for composite fibers, and corresponded respectively to combustion of LA and polymer chains (PA6) in composite fibers. The addition of CNTs reduced the peak of heat release rate (PHRR) of electrospun composite fibers, contributing to the decreased flammability properties. The improved thermal conductivity performances of LA/PA6/CNTs composite fibers was also confirmed by comparing the melting/freezing times of LA/PA6 composite fibers with that of neat LA powders. The results from the SEM observation showed that the composite fibers had no appreciable variations in shape and diameter after heating/cooling processes.     

Aquaculture and international trade

Abstract

In contrast to the stabilization or decline of wild fishery harvests, aquaculture's contribution to the world fish supply is steadily increasing. Aquaculture has begun to have a major influence on the trade of export‐orientated species such as salmon and shrimp. This paper reviews the role of aquaculture in international trade and the research which has been conducted to examine its influence. Despite the growing significance of aquaculture on international trade, especially for shrimp and salmon, formal analysis of the shrimp trade is sparse, only moderate for salmon, and essentially nonexistent for other species. This paper also presents specific examples of how aquaculture has played an important role in international trade. These include an examination of: (1) the influence of shrimp aquaculture and trade on the development of a shrimp futures contract; and (2) the countervailing duty and antidumping case against the Norwegian farmed salmon industry.     

Effects of Hormonal Supplementation on Nuclear Maturation and Cortical Granules Distribution of Canine Oocytes During Various Reproductive Stages

The aim of this study was to evaluate the effects of hCG, progesterone and oestradiol supplementation on nuclear and cytoplasmic maturation of canine oocytes cultured for 24, 48, 72 and 96 h. Oocytes obtained from 18 healthy bitches were divided into three groups according to their reproductive status (follicular, luteal and anoestrus stages) and cultured in TCM 199 + 25 UI/ml of hCG + 1 μg/ml of progesterone + 1 μg/ml of 17‐β oestradiol or without hormonal supplementation (control) for different periods. Then, they were stained with FITC‐LCA‐Hoescht for chromatin configuration and cortical granules distribution and evaluated under an epifluorescence microscope. Culture time and the influence of different stages of the oestrous cycle were also evaluated. The present study demonstrated that there was no significant difference among the reproductive stages. With regards to culture medium, only oocytes from the supplemented medium were able to complete meiosis; however, significant difference was only noticed in the percentage of MI stage oocytes (p < 0.05) in the follicular and luteal group at 72 h of culture. Most oocytes in germinal vesicle, germinal vesicle breakdown and metaphase I stage had cortical granules distributed throughout the cytoplasm (immature pattern), irrespective of the culture period (p < 0.05). Cortical granules distributed immediately beneath the plasma membrane (mature) was only observed in metaphase II stage oocytes, but not all of them presented matured cytoplasm. Our results reveal that cortical granules distribution in canine oocytes matured in vitro did not progressed in correspondence with nuclear stage changes and are in accordance with those from other species.