Genetic Transformation of Watermelon with Pumpkin DNA by Low Energy Ion Beam-mediated Introduction

The No.601 watermelon (citrullus lanatus) seeds were treated with 25 keV N+ implantation at the dosage of 7.8 ×1016 ions/cm2. After treatment, watermelon seeds were incubated with 380μg/μl pumpkin (Cucubita, maxima Duch) DNA solution at 35 ℃ for 5 hours. By two-generations of selection and resistance screening at seedling stage, one transformed material was selected out, whose rind color is similar to that of the donor pumpkin and whose size of seeds is between that of the donor and the receptor. Using AFLP (amplified fragment length polymorphism) technique, two polymorphic DNA fragments were amplified. This primarily testified that the donor DNA fragments/gene were introduced into the receptor cell and integrated into the genomic DNA of the receptor.

Preliminary Studies on Base Substitutions and Repair of DNA Mismatch Damage Stimulated by Low Energy N^+ Ion Beam Implantation in Escherichia coli

Ever since the low energy N+ ion beam has been accepted that the mutation effects of ionizing radiation are attributed mainly to direct or indirect damage to DNA. Evidences based on naked DNA irradiation in support of a mutation spectrum appears to be consistent, but direct proof of such results in vivo are limited. Using mutS, dam and/or dcm defective Eschericha coli imitator strains, an preliminary experimental system on induction of in vivo mutation spectra of low energy N+ ion beam has been established in this study. It was observed that the mutation rates of rifampicin resistance induced by N+ implantation were quite high, ranging from 9.2 x 10~8 to 4.9× 10~5 at the dosage of 5.2×1014 ions/cm2. Strains all had more than 90-fold higher mutation rate than its spontaneous mutation rate determined by this method. It reveals that base substitutions involve in induction of mutation of low energy nitrogen ion beam implantation. The mutation rates of mutator strains were nearly 500-fold (GM2929), 400-fold (GM5864) and 6-fold larger than that of AB1157. The GM2929 and GM5864 both lose the ability of repair DNA mismatch damage by virtue of both dam and dcm pathways defective (GM2929) or failing to assemble the repair complex (GM5864) respectively. It may explain the both strains had a similar higher mutation rate than GM124 did. It indicated that DNA cytosine methylase might play an important role in mismatch repair of DNA damage induced by N+ implantation. The further related research were also discussed.

Study of Biological Effects of Low Energy Ion Implantation on Tomato and Radish Breeding

Biological effects of 30 keV low energy nitrogen ion implantation on the seeds of five types of tomato and one type of radish were investigated. Results showed that low energy ions have different effects on different vegetables. The whole dose-response curve of the germination ratio did not take on ＂the shape of saddle＂, but was a rising and falling waveform with the increase or decrease in ion implantation. In the vegetable of Solanaceae, two outstanding aberrant plants were selected from M1 of Henan No.4 tomato at a dose of 7x 1017 nitrogen ions/cm2, which had thin-leaves, long-petal and nipple tip fruit stably inherited to Mr. Furthermore the analysis of the isozyme showed that the activity of the mutant tomato seedling was distinct in quantity and color. In Raphanus sativus L., the aberrances were obvious in the mutant of radish 791 at a dose of 5×10^17 nitrogen ions/cm^2, and the weight of succulent root and the volume of growth were over twice the control＇s. At present, many species for breeding have been identified in the field and only stable species have been selected for the experiment of production. It is evident that the low energy ion implantation technology has clear effects on vegetables＇ genetic improvement.

Bioeffects of Low Energy Ion Beam Implantation:DNA Damage,Mutation and Gene Transter

Low-energy ion beam implantation （10 - 200 keV） has been proved to have a wide range of biological effects and is broadly used in the breeding of crops and micro-organisms.To understand its mechanisms better and facilitate its applications, the developments in the bioeffects of low energy ion beam implantation in the past twenty years are summarized in this paper.

A Preliminary Study on DNA Mutation Induction of Maize Pollen Implanted by Low Energy N^+ Beam

The maize pollens were implanted with seven different doses of 30 keV N+ beam respectively, The genomic DNA polymorphism from treated pollens were analyzed with 104 primers by using RAPD respectively. The results showed that N^+ beam-induced mutation of maize pollens can result in the change of their DNA bases. The mutation is not properly random and its frequency increases with a rise in 30 keV N+ beam doses. It is conformed with A-G transformation, which is one of the most important factors in DNA bases induced by N+ beam.

Interaction between Low Energy ions and the Complicated Organism

Low energy ions exist widely in natural world, but people pay a little attention on. the interaction between low energy ions and matter, it is even more out of the question of studying on the relation of low energy ions and the complicated organism. The discovery of bioeffect induced by ion implantation has, however, opened a new branch in the field of ion beam application in life sciences. This paper reports recent advances in research on the role of low energy ions in Chemical synthesis of the biomolecules and application in genetic modification.

Etching and Damage Action on Microbes' Cells by Low Energy N^+ Beam

The action of etching and damage by 20 keV N+ beam on the cells of Deinococcus radiodurans and Escherichia coli was investigated by scanning electron microscope (SEM) and the electron spin resonance (ESR) spectrum of free radicals. The results showed that N+ implantation exerted the direct action of etching and damage of momentum transferring and the indirect action of the free radicals of energy deposition on their cells, many microholes were found on the surface of cells' wall and /or membrane by SEM, the damaged DNA was determined using DNA unwinding technique, and the signal of free radicals was measured by ESR. The degree of damage to cells by ion beam gradually increased with the increase implantation dose. With the post-treatment of 2 mmol/l caffeine and 0.5 mmol / l Na2-EDTA, the survival rate of D.radiodurans and E.coli further decreased in the order of caffeine > Na2-EDTA > control, and this suggested that low energy ion beam could be implanted into nucleus, doing a damage to DNA and resulting in the mutation of organisms.

Dependence of single event upsets sensitivity of low energy proton on test factors in 65 nm SRAM

In order to accurately predict the single event upsets （SEU） rate of on-orbit proton, the influence of the proton energy distribution, incident angle, supply voltage, and test pattern on the height, width, and position of SEU peak of low energy protons （LEP） in 65 nm static random access memory （SRAM） are quantitatively evaluated and analyzed based on LEP testing data and Monte Carlo simulation. The results show that different initial proton energies used to degrade the beam energy will bring about the difference in the energy distribution of average proton energy at the surface and sensitive region of the device under test （DUT）, which further leads to significant differences including the height of SEU peak and the threshold energy of SEU. Using the lowest initial proton energy is extremely important for SEU testing with low energy protons. The proton energy corresponding to the SEU peak shifts to higher average proton energies with the increase of the tilt angle, and the SEU peaks also increase significantly. The reduction of supply voltage lowers the critical charge of SEU, leading to the increase of LEP SEU cross section. For standard 6-transitor SRAM with bit-interleaving technology, SEU peak does not show clear dependence on three test patterns of logical checkerboard 55H, all＂ 1＂, and all ＂0＂. It should be noted that all the SEUs in 65 nm SRAM are single cell upset in LEP testing due to proton＇s low linear energy transfer （LET） value.

High-Temperature Annealing Induced He Bubble Evolution in Low Energy He Ion Implanted 6H-SiC

Bubble evolution in low energy and high dose He-implanted 6H-SiC upon thermal annealing is studied. The （0001）-oriented 6H-SiC wafers are implanted with 15keV helium ions at a dose of 1×10^17 cm^-2 at room temperature. The samples with post-implantation are annealed at temperatures of 1073, 1173, 1273, and 1473K for 30rain. He bubbles in the wafers are examined via cross-sectional transmission electron microscopy （XTEM） analysis. The results present that nanoscale bubbles are almost homogeneously distributed in the damaged layer of the as-implanted sample, and no significant change is observed in the He-implanted sample after 1073 K annealing. Upon 1193 K annealing, almost full recrystallization of He-implantation-induced amorphization in 6H-SiC is observed. In addition, the diameters of He bubbles increase obviously. With continually increasing temperatures to 1273K and 1473 K, the diameters of He bubbles increase and the number density of lattice defects decreases. The growth of He bubbles after high temperature annealingabides by the Ostwald ripening mechanism. The mean diameter of He bubbles located at depths of 120-135 nm as a function of annealing temperature is fitted in terms of a thermal activated process which yields an activation energy of 1.914＋0.236eV.

Accurate Analysis on Bluetooth Low Energy Neighbor Discovery

The basic concept of Bluetooth Low Energy (BLE) is short packet transmission and transient connection. It can quickly establish a connection, send data, and quickly disconnect, so that neighbor discovery is frequent and becomes an important issue. In the neighbor discovery which includes advertising and scanning, the BLE specification defines several important parameters. The parameters on the advertiser side include advertising interval, advertising duration, etc. On the scanner side, there are scan interval, scan window, etc. How to configure these parameters for quick neighbor discovery has been troublesome for BLE implementers. Prior analyses on BLE discovery process also showed some disagreements or made some incorrect assumptions. In this paper, we use rigorous probability-theory based derivations to obtain different kinds of successful discovery probabilities. We clarify disagreements in prior works and also provide insights on how to configure parameters for maximizing discovery probability. In particular, we prove that the discovery probabilities on each of the three channels are correlated. We also find that, when the advertising duration is set close to some multiples of the scan interval, an ill-fated synchronization problem will occur. To have a high discovery probability, both scan window and scan interval should be set at a large value, though it might not be good for energy saving.

Biological Effects of Low Energy Ar^+Ion Bombardment on Silkworm Eggs:a Novel Animal Model

In this study, we found for the first time that silkworm eggs were able to survive in vacuum for a long period of time. Subsequently, 10w energy Ar＋ ions with different energies and fluences were used to bombard silkworm eggs so as to explore the resulting biological effects. Results showed that （i） the exposure of silkworm eggs to vacuum within 10 rain did not cause significant impact on the hatching rates, while the irradiation of silkworm eggs by Ar＋ ions of 25 keV or 30 keV with fiuences ranging from 2.6×2.6× 10^15 ion/cm2 to 8×2.6 × 10^15 ion/cm2 caused a significant impact on the hatching rates, and the hatching rates decreased with the increase in the fluence and energy level; （ii） the irradiation of silkworm eggs by Ar＋ ions of 30 keV with a fluence of 8×2.6 × 10^15 ion/cm2 or 9×2.6 × 10^15 ion/cm2 resulted in a noticeable etching on the egg shell surface which could be observed by a scanning electron microscope; and （iii） the irradiation of silkworm eggs by Ar＋ ions of generated several mutant phenotypes which were 30 keV with a fiuence of 9×2.6× 10^15 ion/cm2 observed in the 5th instar silkworms and a moth.

Energy Transformation in Mammalian Cell for Low Energy Ion Beam Impinging

This study investigates the stopping power of a mammalian cell for low energy ions. The energy equation of the incident ion has been conducted based on the elastic collision between the pairs of nuclei in order to establish the stopping powers of the mammalian cell for low energy ion implantation. Based on the biological structure of the mammalian cell and the measured thickness of the V79 cell, a physical structural model is proposed that the attached cell is approximately of a model of a constringent multi-membrane structure （C-2M model） in order to analyse the stopping power of the mammalian cell for low energy ions. With this model we have determined the mean line energy transfer, and roughly estimated the depth of ion implantation on the selected Chinese hamster V79 cell for 30 keV N^＋ ions at a flux of 1 × 10^15 ion/cm^2, which is in agreement with those by using Monte Carlo methods.

Creation of High-Yield Polyhydroxyalkanoates Engineered Strains by Low Energy Ion Implantation

Polyhydroxyalkanoates （PHAs）, as a candidate for biodegradable plastic materials, can be synthesized by numerous microorganisms. However, as its production cost is high in comparison with those of chemically synthesized plastics, a lot of research has been focused on the efficient production of PHAs using different methods. In the present study, the mutation effects of PHAs production in strain pCB4 were investigated with implantation of low energy ions. It was found that under the implantation conditions of 7.8×10^14 N^＋/cm^2 at 10 keV, a high-yield PHAs strain with high genetic stability was generated from many mutants. After optimizing its fermentation conditions, the biomass, PHAs concentration and PHAs content of pCBH4 reached 2.26 g/L, 1.81 g/L, and 80.08% respectively, whereas its wild type controls were about 1.24 g/L, 0.61 g/L, and 49.20%. Moreover, the main constituent of PHAs was identified as poly-3-hydroxybutyrates （PHB） in the mutant stain and the yield of this compound was increased up to 41.33% in contrast to that of 27.78% in the wild type strain.

Mutation Breeding of an Organic Phosphorus-Solubilizing Bacterium B3 by Low Energy Ion Beam Implantation

A preliminary study on the mutation breeding of an organic phosphorus-solubilizing bacterium B3 by low-energy N^＋ ion beam was conducted. Analysis of dosage vs. survival rate and mutation rate showed that the dosage of 3×10^15 ions/cm^2 was optimal for the mutation. Some parameters for determining the efficient phosphorus content were studied to simplify the protocols for screening. Ultimately one reliable mutant was screened out under plating and flask-culturing screening conditions. Importantly, a novel phosphorus-dissolving mechanism is reported for the first time in terms of bio-surfactant production, which indicates that bio-surfactant might play a vital role in phosphorus-dissolving for some phosphobacteria.

Electron excitation processes in low energy collisions of hydrogen-helium atoms

The electron excitation processes of H(1s)+He(1s^(2))→H(2s/2p)+He(1s^(2))are studied in impact energy range of 20-2000 e V/u by using the quantum-mechanical molecular orbital close-coupling(QMOCC)method.Total and state-selective cross sections have been obtained and compared with the available theoretical and experimental results.The results agree well with available measurements in the overlapping energy regions overall.The comparison of our results with other theoretical calculations further demonstrates the importance of considering a sufficient number of channels.The datasets presented in this paper,including the excitation cross sections,are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00083.

Manganese-Based Catalysts for Indoor Volatile Organic Compounds Degradation with Low Energy Consumption and High Efficiency

With the development of industrialization,the emission of volatile organic compounds(VOCs)to atmosphere causes serious environmental problems and the treatment of VOCs needs to consume a lot of energy.Moreover,indoor VOCs are seriously harmful to human health.Thus,there is an urgent requirement for the development of indoor VOCs treatment technologies.Catalytic degradation of VOCs,as a low energy consumption,high efficiency,and easy to achieve manner,has been widely studied in related fields.As a kind of transition metal catalyst,manganese-based catalysts have attracted a lot of attention in the catalytic degradation of VOCs because of their unique advantages including high efficiency,low cost,and excellent stability.This paper reviews the state-of-the-art progress of manganese-based catalysts for VOCs catalytic degradation.We introduce the thermocatalytic,photocatalytic and photo-thermocatalytic degradation of VOCs on manganese-based catalysts in this paper.The optimization of manganese-based catalysts by means of structural design,decorating modification and defect engineering is discussed.

Damaging Effect of Low Energy N^+ Implantation on Aspergillus niger Spores

The mutant effects of a keV range nitrogen ion （N＋） beam on enzyme-producing probiotics were studied, particularly with regard to the induction in the genome. The electron spin resonance （ESR） results showed that the signal of ESR spectrum existed in both implanted and non-implanted spores, and the yields of free radicals increased in a dose-dependent manner. The ionic etching and dilapidation of cell wall could be observed distinctly through the scanning electron microscope （SEM）. The mutagenic effect on genome indicated that N＋ implantation could make base mutation. This study provided an insight into the roles low-energy ions might play in inducing mutagenesis of micro-organisms.

Low Energy Dislocation Structure in Deformed Metals

In this paper,the dislocation distribution struc- ture in deformed metal is discussed.The flow stress of material for the heterogeneous dislocation distri- bution which tends to the flow stress for the homo- geneous dislocation distribution in the limiting case is derived.The causes and the effects of the long range internal stresses are discussed.The total deformation energy of material system is obtained and the trend of evolution of dislocation distribu- tion in deformed metals is discussed simultaneously. No micromechanisms of dislocations are involved in the discussion,therefore the theory developed in this paper is universal.

Developing a New Security Framework for Bluetooth Low Energy Devices

Wearable devices are becoming more popular in our daily life.They are usually used to monitor health status,track fitness data,or even do medical tests,etc.Since the wearable devices can obtain a lot of personal data,their security issues are very important.Motivated by the consideration that the current pairing mechanisms of Bluetooth Low Energy(BLE)are commonly impractical or insecure for many BLE based wearable devices nowadays,we design and implement a security framework in order to protect the communication between these devices.The security framework is a supplement to the Bluetooth pairing mechanisms and is compatible with all BLE based wearable devices.The framework is a module between the application layer and the GATT(Generic Attribute Profile)layer in the BLE architecture stack.When the framework starts,a client and a server can automatically and securely establish shared fresh keys following a designed protocol;the services of encrypting and decrypting messages are provided to the applications conveniently by two functions;application data are securely transmitted following another protocol using the generated keys.Prudential principles are followed by the design of the framework for security purposes.It can protect BLE based wearable devices from replay attacks,Man-in-The-Middle attacks,data tampering,and passive eavesdropping.We conduct experiments to show that the framework can be conveniently deployed with practical operational cost of power consumption.The protocols in this framework have been formally verified that the designed security goals are satisfied.

Multi-effects and Mechanism of Broad Beau M_1 Root-tip Cells Implanted by Low Energy N^+ Beam

Broad beans were divided into six groups and implanted with N+ beam of 30 KeV, 8 × 1016/cm2 per time for various radiating times respectively. Besides the statistics of its vigor of germination, the M1 root-tip cells of these broad beans were systematically analyzed on their changes in mitotic percentage, morphology and behavior of chromosomes, along with the structure o f cytoskeletons, including microtubule and intermediate filament. Based on all results of these studies, our opinions have been expressed in the report on the mechanism of low-energy N+ beams effecting on higher dicotyledons such as broad beau.