Objective:To investigate the clinical and pathological factors of metastasis in patients with oral squamous cell carcinoma (OSCC)and clinical lymph node-negative(cN0).Methods:85 patients of OSCC with cN0 treated in 2008-07 -2013-07 were inves-tigated retrospectively.Results:In the 85 patients 24(28.34%)showed occult metastasis.Patient's gender,lesion location had no im-pact to metastasis(P >0.05),the patient's age,tumor size,growth pattern and histopathologic grade showed significant influence on the metastasis of OSCC(P <0.05).Conclusion:The greater tumor volume,lower differentiation degree and young age are the factors of higher occult lymph node metastasis.Selective neck dissection treatments of OSCC is recommended.

Objective By analyzing and commentating the current research situation of recycling of residues in China, to provide reference for correlational research in future. Methods By taking periodical literature and national patent literature named residues at home and abroad as sample, using content analysis approach, the thesis conducts researches and analysis by computer statistical function. Results The literature mainly distributed in such branches as organic chemical industry, gardening, animal husbandry and animal medicine. The research involves residues and feedstuff, edible mushrooms, fertilizer, and analysis and application of the ingredients of residues. The types of residues mainly include Radix Liquorice, Radix Salviae Miltiorrhizae and brag-zhun, etc. And more than ten kinds of technologies of processing and curing residues were involved. Conclusion Research of recycling of residues in China is insufficient, the difficulty lies in the recycling of antibiotic residues. There will be a bright prospect in resource utilization of residues.

Objective To establish a new multiplex-PCR assay to improve the detection rate of mutations in the DMD gene in Chinese patients. Methods A retrospective review of DMD deletion spectrum of 355 DMD patients with deletions all over the gene was performed. All deletions were confirmed by " one-step approach" diagnostic procedure and MLPA analysis. The exons with high frequency of mutations were identified to constitute the amplification system and the PCR conditions were optimized. Results Two new multiplex-PCR assays were established. Assay one was used to detect 10 exons including exon 5, 8, 17, 44, 45, 47, 49, 50, 51 and 52 of DMD gene, in two PCR sets. The theoretical detection rate would be 92% (326/355). Assay two was used to detect 5 exons including exon 12, 19, 35, 43 and 54, which could be used to screen additional 5% (17/355) deletion cases. The method was validated in other 22 DMD patients. Multiplex-PCR results were completely identical to the MLPA results in all 22 DMD patients. Conclusions The two multiplex-PCR assays were established based on the analysis of 355 Chinese DMD patients with gene deletions. It is believed that the new approach would be more applicable for deletion detection on the Chinese DMD patients since the DMD cases involved were from the whole country.

Objective To develop a rapid,reliable and convenient approach for diagnosing the homozygous deletion of SMN1 gene.Methods SMN1 gene was amplified specifically with double allele-specific PCR(AS-PCR).Meanwhile,one inrelevant gene was amplified as internal control by PAGE and agarose gel electrophoresis analysis to determine whether the sick children were with homozygous deletion of SMN1 genes.Results The homozygous deletion of exon7 in SMN1 gene was identified by agarose gel electrophoresis or PAGE accurately.Conclusion Compared to PCR-RFLP and DHPLC used in the past,this approach can diagnose homozygous deletion of SMA much more accurate,easier and more convenient without completed following analyses.

Objective:To summarize the best evidence for the prevention and nursing of peri-implant diseases in patients with dental implants.Methods:Guidelines, systematic reviews, evidence summaries, and expert consensus on prevention and nursing of peri-implant diseases in patients with dental implants were electronically retrieved on Guidelines International Network, Agency for Healthcare Research and Quality, Medlive, UpToDate, BMJ Best Practice, Cochrane Library, Web of Science, PubMed, China Biology Medicine disc, China National Knowledge Infrastructure and so on. The search period was from database establishment to June 1, 2023. Two researchers conducted a quality evaluation and extracted evidence from the included literature.Results:A total of 15 articles were included, including two guidelines, six expert consensus, and seven systematic reviews. Twenty pieces of evidence on the prevention and nursing of peri-implant diseases in patients with dental implants were summarized from five aspects: risk factor assessment, nursing measures, oral hygiene guidance, monitoring and follow-up, and health education.Conclusions:The best evidence for the prevention and nursing of peri-implant diseases in dental implant patients summarized is scientifically sound. Medical and nursing staff can apply evidence based on clinical context and patient wishes.