In the early autumn of 214, a new variety of tussah silkworm was developed by the Liaoning Provincial Sericulture Research Institute. This innovative strain was created using advanced techniques such as reverse selection technology, seasonal conservation breeding methods, and the application of hybrid vigor. After 13 years of dedicated research and improvement, this silkworm variety has proven to be highly productive, of superior quality, disease-resistant, cold-tolerant, and able to thrive on roughage. The cocoons produced are known for their excellent dissipative properties, making it a promising advancement in the tussah silkworm industry.
The introduction of this variety not only helps preserve silkworm resources and prevent soil erosion but also improves the layout and production capacity of tussah silkworm farming. Moreover, it has successfully expanded the geographic range of tussah production in China to five northern latitudes, with an expected increase in production scale by 2 to 3 times. The variety has earned the Second Prize for Scientific and Technological Progress in Liaoning Province, highlighting its significance in agricultural innovation.
One of the key characteristics of the Early Autumn 214 silkworm is its distinct appearance: larvae are pale yellow with a ginger-yellow back and banana-yellow sides. The cocoons are gray-brown, and few moths emerge after scabbing in early autumn. Female moths are cinnamon brown, while males are light brown leaf-colored. The moth emergence rate and egg-laying capacity are high, with each female laying around 290 eggs, and a hatching rate of up to 97%. The spring rearing period lasts 50–53 days, while the autumn cycle takes 43–50 days.
This variety is also highly adaptable to rough feeding conditions, remains active, and is easy to raise. As long as they avoid eating light loquat leaves, there’s no risk of the "running slope litchi" issue. It demonstrates strong resistance to silkworm diseases. Silk tests show that the silk yarn length reaches 986.45 meters, with a solution silk length of 661.32 meters, an unwinding rate of 67.04%, and a recovery rate of 61.09%. The silk is soft, shiny, and of high quality.
In terms of productivity, the Early Autumn 214 shows remarkable stability, with a conversion rate of up to 99.57%. From 2001 to 2003, over 26,890 silkworms were raised across five provinces, 16 cities, and 38 townships in northern China. The average yield per silkworm reached 772.4 kilograms, representing a 36.2% increase in silkworm yield and a 15.5% rise in silk production. In Mudanjiang City, Heilongjiang Province, the average pupa weight per autumn silkworm was 862.0 kilograms, a 23.3% increase compared to traditional varieties. Field data indicates that each cocoon generates about 2,490.14 yuan in income, showing significant economic benefits.
For optimal rearing, the silkworms should be kept neat, with timely pruning and tree changes to ensure sufficient leaf supply and promote robust growth. During the 3rd to 9th day of the 5th instar, leaves should be concentrated and appropriately thinned. When selecting trees for two fields and nesting areas, scientific allocation based on actual field conditions is essential to protect the ecological environment and improve resource utilization.
During the preparation for single crosses, the silkworm body of 883932 is larger and slightly longer than the four-greenish yellowish brown type, with a higher accumulated temperature energy by about 15°C. Therefore, it is crucial to receive the ants early and dry them out of the reservoir to ensure proper timing for the fourth instar. Hybrid adults should meet at the right time, with careful selection and timely raising to improve the quality of the eggs.
During winter and spring preservation, special attention must be given to preventing artificial mixing to ensure regular and thorough seed production for the next year's early autumn season, laying a solid foundation for high yields.
Over the years, scientific experiments and field practices have confirmed that the Early Autumn 214 and its parents exhibit strong resistance and adaptability, making them ideal for tussah silkworm cultivation in China, especially in the three northeastern provinces. Cities such as Jiamusi, Mudanjiang, Ning'an, Linkou, Hailin, and Jixi have successfully raised this variety, achieving impressive economic returns.
Bone Screw
Bone screws, also known as fracture fixation screws, are commonly used in clinical practice to fix orthopedic implants.
Bone screws are usually used to fix internal fractures or dislocations by directly screing into two different bone blocks or fixing an internal implant such as a bone plate to achieve fracture fixation, position the bone and promote its healing. Bone screws are used in a wide range of areas, including the shoulder, elbow, hip, knee, spine, etc. For example, pedicle screw systems are used for spinal fusion, and compression bone screws are commonly used for foot and ankle surgery or fixation of other fractures under pressure. Similar to traditional mechanical screws, the main structures of bone screws also include nail cap, nail body, and nail tip. Screws can be used to fix bone plates or bone fragments. When used for the former, they are called plate screws, and when used for the latter (to prevent the collapse of bone fragments), they are called positional screws. The latter can be inserted into the plate holes, and can be placed on the bone alone (also known as compression screws). Compression screws can be used to increase interfragment pressure.
(1) The screw cap
The screw cap has three main functions: the first is to optimize the force. The protruding cap makes the contact area between the screw and bone larger, increases the load area, optimizes the local force at the screw insertion site, and reduces the risk of bone rupture caused by excessive stress. The second is the positioning effect. The prominent cap makes the bone nail can only be screwed into a certain depth to prevent the whole bone nail from being screwed into the bone completely. The third function is to provide the position of force application by rotating the force groove at the cap to move the bone nail forward and drive it into the bone. Now, the force groove is mostly inner hexagonal, which does not require axial force to maintain the actuator in the center position and is suitable for a wider range of fractures.
(2) Screw the body
The size of the nail body determines the strength and fatigue resistance of the bone nail. The larger the diameter of the nail body, the stronger the strength will be, and the corresponding fatigue resistance will be better. In addition to the diameter of the nail body, the pitch and tooth depth of the screw body thread are also the key parameters of the nail body design. Different thread design has an important effect on the pressure and occlusal performance of the screw.
(3) Screw tip
Tapping is the process of phalangeal nail cutting thread in the bone. According to the shape of the nail tip, the bone nail can be divided into self-tapping nail and non-self-tapping nail. The nail tip of the self-tapping nail is sharper and can be directly screwed into the bone without pre-drilling. Usually, self-tapping screws are used for Cancellous bone, and the bone is compressed when the screw is inserted, so as to increase the bone density of the occlusal part locally and enhance the occlusal effect. However, when inserting screws in Cortical bone, the screw channel is generally pre-punched, and then the bone screw is screwed. Usually, the self-tapping screw is not directly used to prevent the bone screw from being stuck or damaged because the cortical bone is too hard.
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