Abstract In order to improve the prevention and control of myopia, this paper examines the significance of hyperopia reserves and its correct application, identifies problems requiring further attention and sums up past experiences. It puts forward a prevention and control system of myopia after introduction of the physiotherapy instruments, especially those based on the principle of red light. This paper discusses some mechanisms of low concentration atropine eye drops in preventing and controlling myopia. Finally, future research directions are proposed.

In order to understand the characteristics of avian leukosis virus(ALV)infection and the polymorphisms of receptor genes Tva,Tvb and NHE1 sequences in different Qingyuan Ma chick-en breeding farms,the isolation and identification of exogenous ALV virus,receptor gene amplifi-cation and sequencing analysis were carried out in five Qingyuan Ma chicken breeding farms.The results of virus isolation and subtype identification showed that the positive rate of exogenous ALV virus isolation in farms A,B and C was less than 5％,among which there was ALV-J infection alone in farm A,mixed infection with ALV-J and ALV-K in farm B,ALV-K infection a-lone in farm C,and no exogenous ALV infection was detected in farm D and E.Polymorphism anal-ysis of recipient genes showed that there were different frequencies of Tvar3,Tvar4 and Tvbr3 re-sistance alleles in A-E farms,and the distribution frequency of Tvar3 was 0.2-0.6,the distribution frequency of Tvar4 was 0.3-0.7,and the distribution frequency of Tvbr3 was 0.1-0.7.In addition,there were Tvar5 resistance alleles in both B and D farms,with a distribution frequency of 0.2.A to-tal of 18 SNP mutations occurred in the NHE1 receptor gene sequence,and further analysis showed that positions 1 279,1 361,1 369,1 406,1 442,and 1 912 were non-synonymous mutations,which could cause changes in amino acids.The study suggested that there were differences in the exogenous ALV and its subtypes among the five Qingyuan Ma chicken breeders,and each farm should have a more targeted and unique purification strategy.The distribution of Tva and Tvb re-sistance alleles at different frequencies,along with the occurrence of 6 non-synonymous mutations in the NHE1 gene,indicate that Qingyuan Ma chicken have the potential of genetic resistance breeding.

Vaccination is a main measure for protecting chickens against Marek's disease,while it is not able to suppress the infection,proliferation,transmission,and virulence enhancement on Marek's disease virus.Inhibiting the proliferation of Marek's disease virus in chicken is therefore an im-portant option for enhancing defense effectiveness.In this study,a compound,DUBs-IN-1,was found to inhibit the activity of MDV049,a protease encoded by Marek's disease virus,via screening a protease inhibitor library using MDV049 as target and ubiquitin probe.Molecular docking re-vealed that DUBs-IN-1 can interact with the residues which formed the catalytic pocket of MDV049,blocking the interaction between Ub substrate and the catalytic center of MDV049,then suppress the activity of MDV049 with competitive inhibition.Using the CPE model,it was found that DUBs-IN-1 at the concentration of 0.35 and 0.70 μmol/L significantly inhibited the CPE in-duced by Marek's disease virus in CEF cells.Quantitative analysis revealed that DUBs-IN-1 inhibi-ted the proliferation of Marek's disease virus in CEF cells(P＜0.01).Furthermore,it was found that the administration of 80 and 150 pg/(kg·d)of DUBs-IN-1 in chicken infected by Marek's disease virus significantly inhibited the proliferation of MDV in T cells(P＜0.01).In summary,this study demonstrated that the compound DUBs-IN-1 is able to inhibit the proliferation of Marek's disease virus in chicken cells,laying a theoretical and practical foundation for further de-velopment of the drugs against Marek's disease virus.

Purified protein derivative(PPD)skin tests often yield poor specificity, so that to develop new serological antigens for distinguishing between Mycobacterium tu-berculosis infection and Bacille Calmette-Guerin(BCG)vaccination is a priority, especially for developing countries like China. We predicted the antigenicity for selected open reading frames(ORFs)based on the genome sequences of M. tu-berculosis H37Rv and M. bovis BCG, as well as their functions and differences of expression under different stimulus. The candidate ORFs were cloned from H37Rv sequences and expressed as recombinant proteins in Escherichia coll. We studied the serodiagnostic potential of 11 purified recombinants by using enzyme-linked immunosorbent assay(ELISA)and involving a cohort composed of 58 TB patients (34 males and 24 females), 8 healthy volunteers and 50 PPD-negative individuals before and after BCG vaccination. For all the 11 antigens, the median OD val-ues for the sera from TB patients were statistically significantly higher than those for PPD-negative individuals before or after BCG vaccination(P<0.01). They had at least 92% specificity in healthy controls and six seroantigens(Rv0251c, Rv1973, Rv2376c, Rv2537c, Rv2785c and Rv3873A)were never reported with seroantigenicities previously. Thus the approach combining comparative genomies, bioinformatics and ELISA techniques can be employed to identify new seroantigens distinguishing M. tuberculosis infection from BCG vaccination.