Duck enteritis virus (DEV) is a herpesvirus that causes an acute, contagious and fatal disease. In the present article, the DEV UL4 gene was cloned and sequenced from a vaccine virus. A degenerate oligonucleotide primer for the consensus site of herpesvirus UL3 gene and a specific primer located in UL5 were used in the polymerase chain reaction (PCR) to amplify a DNA product 2 086 bp in size. DNA sequence analysis revealed that a 714 bp open reading frame (ORF) of DEV encoding a 237 amino acid polypeptide is homologous to the family of herpesvirus UL4 proteins and therefore has been characterized as a DEV UL4 gene. Alignment of the DEV UL4 protein sequence with those of other alphaherpesviruses showed that 10 amino acid residues are completely conserved. Phylogenetic tree analysis showed that the seventeen alphaherpesviruses viruses analyzed were classified into four large groups, and the duck enteritis virus branched separately, closely related to the Mardiviruses group comprising Gallid herpesvirus 2 (GaHV-2), Gallid herpesvirus 3 (GaHV-3) and Meleagrid herpesvirus 1 (MeHV-1). The present study showed that the evolutionary relationship of the UL4 protein could be used for classification of alphaherpesviruses.

OBJECTIVE:To provide reference for further implementation and perfection of National Essential Medicine Sys-tem. METHODS:Stratified random sampling method was used to select 252 doctors from Sichuan Luzhou. Questionnaire survey was performed among them about recognition and behavior of them to National Essential Medicine System. Related investigation da-ta was analyzed statistically. RESULTS:A total of 252 questionnaires were issued and 243 valid questionnaires were collected with effective recovery rate of 96.4%. Of 242 respondents who had heard of National Essential Medicine System,the respondents who had heard but not clear occupied the highest percentage (52.1%). Of 149 participants who had participated in national essential medicine knowledge training or study,the proportion ofonly one knowledge training or studywas the highest(57.0%). The sur-vey respondents had a maximum of 45.0% and a minimum of 16.5% of common sense about National Essential Medicine System. After the implementation of National Essential Medicine System,respondents often propagandized National Essential Medicine Sys-tem to diagnosis and treatment objects accounted for only 23.1%. The proportion ofno changechosen for items of work motiva-tion,work efficiency and workload was the highest (all occupied 58.3%);the proportion oflittle influencechosen for item of clinical medication habit was the highest(38.8%). 86.4% of respondents were willing to give priority to the use of national essen-tial medicines;the top 4 reasons wereto obtain training and guidance on the use of essential medicinesto set utilization rate of essential medicines in primary health care institutionsto strengthen the propaganda of National Essential Medicine Systemto evaluate physician's prescriptions regularly. 13.6% were not willing to give priority to the use of national essential medicines;the top 4 reasons werelack of the confidence of the use of national essential medicinespoor accessibility of essential medicinesfear of medical accidents due to prescription essential medicines,lead to medical disputesdon't know what is essential medi-cine. CONCLUSIONS:The primary physicians'perceptions of National Essential Medicine System and the implementation of the System in Luzhou need to be strengthened. The main reason is that few national essential medicine knowledge training or study and poor effects. That the government's supporting poli-cy is not perfect may be one of reasons.