CN110749728B

CN110749728B - Method for contaminating tail gas of chick embryo diesel engine

Info

Publication number: CN110749728B
Application number: CN201910778597.5A
Authority: CN
Inventors: 姜启晓; 郑玉新
Original assignee: Qingdao University
Current assignee: Qingdao University
Priority date: 2019-08-22
Filing date: 2019-08-22
Publication date: 2023-06-30
Anticipated expiration: 2039-08-22
Also published as: CN110749728A

Abstract

The invention discloses a tail gas contamination method of a chick embryo diesel engine, which comprises the steps of taking normal fertilized eggs, quickly illuminating the eggs in a darkroom, marking the positions of an air chamber by using pencils, and drilling two small holes at the two ends of the air chamber as far as possible by using metal probes; extracting tail gas by using an injector for injection; after the injection is finished, the two small holes are closed by transparent adhesive tapes, and the chick embryo is put back into an incubator for continuous incubation; to simulate the effect of continuously exposing the neonate to the tail gas after birth; after chicks hatched, pulmonary toxicity was evaluated. The invention has the beneficial effects that an experimental method for carrying out real tail gas contamination on the first breath of the chicks at birth by utilizing the physiological structure of the chicks is successfully established, so that the influence of the tail gas contamination on the neonatal cardiopulmonary system is evaluated to more reflect the real situation, and a high-value basis is provided for public health risk evaluation.

Description

Method for contaminating tail gas of chick embryo diesel engine

Technical Field

The invention belongs to the technical field of sanitary toxicology, and relates to a tail gas contamination method of a chick embryo diesel engine.

Background

Diesel exhaust is an important atmospheric pollutant, derived from the combustion of diesel engines. The diesel engine is used as a relatively safe and economic power source and widely applied to vehicles, ships, airplanes and the like, but the tail gas discharged by the diesel engine contains a large amount of substances such as nitrogen-oxygen compounds, polycyclic aromatic hydrocarbons, carbon monoxide, inhalable particles and the like, and brings great hidden trouble to human health. At present, a plurality of researches are carried out on animal experiment evaluation aiming at the toxicity effect of tail gas, and the tail gas is found to have obvious lung and heart toxicity, but the current researches are concentrated on adult animal experiments, and have obvious defects: the research on the developmental toxicity of tail gas is less, mainly because of the physiological characteristics of mice, such as the need of a developmental toxicity experiment, the mice are only infected with pregnant female mice, the parent effect is obvious, and the infection of the newborn mice with the first breath cannot be realized accurately. The first air inhaled by the newborn individual at birth fills the originally closed lung, so that the toxicity effect is optimal, and the method is most suitable for the real world manner of influence of atmospheric pollution on the newborn at birth. At present, no experimental method for realizing the contamination is available. Chick embryos are a classical developmental toxicity model, which breaks through the air chamber membrane into the air chamber between 18-19 days during 21 days of incubation, starting to breathe air in the air chamber. The air chamber is of a relatively closed structure, and the tail gas can be injected into the air chamber before the external respiration starts, so that the first breath of the external respiration of the chick embryo can be sucked into the tail gas, and the effect of relatively accurate contamination can be achieved.

Disclosure of Invention

The invention aims to provide a tail gas contamination method of a chick embryo diesel engine, which has the beneficial effects that an experimental method for carrying out real tail gas contamination on first breath of chicks in birth by utilizing a physiological structure of chick embryos is successfully established, so that the influence of tail gas contamination on a neonatal cardiopulmonary system is evaluated to more reflect real conditions, and a high-value basis is provided for public health risk evaluation.

The technical scheme adopted by the invention is carried out according to the following steps:

1. experiment preparation: taking normal fertilized eggs, hatching under standard hatching conditions, preparing tail gas for contamination, and storing the tail gas in a special sample collection bag;

2. taking out the eggs when the eggs are hatched for 18 days, quickly illuminating the eggs in a darkroom, marking the positions of the air chambers by pencils, and drilling two small holes with diameters of about 0.3-0.5mm at the two ends of the air chambers as far as possible by using metal probes, wherein the small holes do not damage chick embryos;

3. extracting tail gas by a 10ml injector, connecting an indwelling needle, removing a needle plug, carefully inserting the soft indwelling needle into an air inlet hole at one side for about 3-5mm, slowly injecting the tail gas based on a certain depth without touching an embryo, and setting a control group and a negative control group which are only injected with common air;

4. after the injection is finished, the two small holes are closed by transparent adhesive tapes, and the chick embryo is put back into an incubator for continuous incubation;

5. setting a secondary exposure group for simulating the effect of continuously exposing the neonate to the tail gas after birth, and carrying out the contamination operation again on the 19 th day;

6. after chicks hatched, pulmonary toxicity was evaluated.

Drawings

FIG. 1 is a schematic diagram of an experimental model;

FIG. 2 is a diagram showing an example of practical experiments;

FIG. 3 is a change in heart rate of a chick after hatching;

FIG. 4 is a lung change of a chick after hatching;

FIG. 5 is a change in right heart wall thickness of a chick after hatching;

fig. 6 is a lung change of a chick after hatching.

Detailed Description

The present invention will be described in detail with reference to the following embodiments.

1. Experiment preparation: taking normal fertilized eggs, hatching under standard hatching conditions, preparing tail gas for contamination (which can be any tail gas to be tested, and using tail gas discharged by sanitation vehicles in Qingdao city in the experiment), and storing in a special sample collection bag.

2. When the eggs are hatched for 18 days (at the moment, the chick embryo does not breathe out yet, namely, the first breath is not inhaled yet, which is equivalent to the period when the human fetus is about to be born), the eggs are taken out, the eggs are quickly illuminated in a darkroom, the positions of the air chambers are marked by pencils (the positions of the air chambers are marked in advance because the air chambers are changed along with the hatching, the air chambers are not marked in advance, the air chambers are preferably used in the day before the experiment is carried out), and two small holes with the diameters of about 0.3-0.5mm are drilled at the two ends of the air chambers as far apart as possible by using a metal probe (or any applicable sharp metal tool), so that attention is not too deep, and otherwise, the chick embryo is injured.

3. The tail gas is extracted by a 10ml injector, the indwelling needle is connected, the needle plug is removed, the soft indwelling needle is carefully inserted into an air inlet hole at one side for about 3-5mm, and the tail gas is slowly injected until the tail gas has a certain depth and does not touch the embryo. The air outlet hole at the other end of the hand can feel that the air is discharged. The volume of the air chamber is only 2-3ml, and 10ml of tail gas can replace most of air in the original air chamber with tail gas. A control group into which only ordinary air was injected and a negative control group were additionally established.

4. After the injection is completed, the two small holes are closed by transparent adhesive tape, and the chick embryo is put back into the incubator for further incubation. The whole process is completed within three to five minutes, and the survival rate of chick embryos is basically not affected.

5. To simulate the effect of the neonate to continue to be exposed to the tail gas after birth, a secondary exposure group was established, and the above contamination operation was performed again on day 19.

6. After chicks are hatched, heart and lung toxicity evaluation is carried out according to the mature existing experimental method.

FIG. 1 is a schematic diagram of experimental mode of a tail gas contamination system of a chick embryo diesel engine. Wherein the tail gas is injected into the air chamber 1 from the air inlet hole, and the original air in the air chamber is discharged 2 from the air outlet hole. Fig. 2 is a diagram showing an example of an actual experiment of the tail gas contamination of a chick embryo diesel engine. The left side of the figure is an egg with marked air chambers and air inlet holes and air outlet holes. The right of the figure is a photograph of the actual injection tail gas contamination. Changes in the heart rate of the chicks after hatching as shown in fig. 3. * Significant change compared with control group, P <0.05. As shown in fig. 4 and 5, the Control is negative Control IC, the air Control I18, the tail gas ID is fed to the chick embryo 18 in 18 days, the tail gas is fed to the chick embryo 18 in 19 days, and the lung of the chick after hatching is changed due to the change of the thickness of the right heart wall of the chick after hatching. The right heart wall was seen to thicken significantly in the I18 and ID groups (18 days of exposure and 18/19 days of exposure). * : there was a significant change compared to the control group, P <0.05. Significant change compared to group I18, P <0.05. Scale bar represents 1000 microns. As shown in FIG. 6, the lung of the chicks after hatching was changed, and obvious inflammatory cell infiltration was observed in the I18 and ID groups (18 days of exposure to infection and 18/19 days of exposure to double exposure). The scale bar represents 70 microns.

The invention is characterized in that: the natural closed air chamber structure in the chick embryo is utilized to realize the contamination of the tail gas of the real diesel engine to the first breath of the newborn chick, thereby realizing the evaluation of the cardiopulmonary toxicity of the newborn chick caused by the tail gas with great practical significance. The method has definite effect, the air control is not obviously different from the negative control, the heart rate is obviously caused by 18 days of contamination and 18/19 days of double contamination, the right heart wall thickness and the lung are changed, and the change of the 18/19 days of double contamination group is more obvious. The method shows that the diesel engine tail gas effectively induces cardiotoxicity and pulmonary toxicity in the hatched chicks through the contamination of the first breath in the contamination model, and the toxicity is in a quantitative effect relationship, so that the model can be used for deep toxicity mechanism research and evaluation of the effects of other inhaled toxins.

The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the invention in any way, and any simple modification, equivalent variation and modification made to the above embodiments according to the technical substance of the present invention falls within the scope of the technical solution of the present invention.

Claims

1. A tail gas contamination method of a chick embryo diesel engine is characterized by comprising the following steps:

6. after chicks are hatched, evaluating pulmonary toxicity;

the tail gas contamination method of the chick embryo diesel engine utilizes the physiological structure of the chick embryo to truly contaminate the tail gas of the first breath of the chick at birth.