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Objective To analyze the research status and development trend of nasopharyngeal carcinoma, to provide a reference for the research of nasopharyngeal cavcinoma in China. Methods We retrieved research articles about nasopharyngeal carcinoma from 2009 to 2019 in the Web of Science (WOS) core database of USA. The number of published articles, research institutions, citations and keywords of the literature were analyzed through the statistical tools provided by CiteSpace and WOS database, and the word frequency, centrality and clustering status of keywords were explored. Results After screening, a total of 4841 articles were obtained, and the number of published articles increased year by year. The top 10 keywords with the highest frequency and top 10 keywords with the highest centrality mainly focus on the treatment and pathogenesis of nasopharyngeal carcinoma. The clustering results concentrated on poor prognosis, advanced nasopharyngeal carcinoma, clinical target area mapping and isopentenyl isoflavones. Conclusion The research hotspot of nasopharyngeal carcinoma is closely related to the geographical distribution of patients. The current research focuses on the treatment and pathogenesis of nasopharyngeal carcinoma.

Objective: To track analysis of viral nucleic acid test results in patients with re-positive SARS-CoV-2 infection, and provide clinical reference for nucleic acid test of re-positive cases., Methods: A retrospective study was conducted. The multiple nucleic acid results of 96 cases with SARS-CoV-2 infection tested by medical laboratory of Shenzhen Luohu Hospital Group from January to September in 2022 were analyzed. The test dates and cycle threshold (Ct) values of detectable positive virus nucleic acid in the 96 cases were summarized and analyzed., Results: A total of 96 patients with SARS-CoV-2 infection were retested re-sampled for nucleic acid testing at least 12 days after the initial positive screening. Among them, 54 cases (56.25%) had Ct value of < 35 for nucleocapsid protein gene (N) and/or open reading frame 1ab gene (ORF 1ab), 42 cases (43.75%) had Ct value ≥ 35. In the re-sampling of infected patients, N gene titers were 25.08 to 39.98 Ct cycles, and ORF 1ab gene titers were 23.16 to 39.56 Ct cycles. Compared with the positive results of the initial screening, the Ct values of N gene and/or ORF 1ab gene positive were increased in 90 cases (93.75%). Among them, the patients with the longest duration of nucleic acid positive could still be positive for double targets (the Ct value of N gene was 38.60, and the Ct value of ORF 1ab gene was 38.11) at an interval of 178 days after the initial positive screening., Conclusions: Patients infected with SARS-CoV-2 can be sustained or repeatedly tested positive for nucleic acid for a long period of time, and most of them had Ct values < 35. But whether it is infectious needs to be comprehensively evaluated by combining epidemiology, variant type, samples with the alive virus, and clinical symptoms and signs.

Objective: To analyze the hematological phenotypes of Hb J-Bangkok and concomitant thalassemia., Methods: In total 72 397 samples were screened by using capillary electrophoresis. Samples with Hb J-Bangkok were identified by DNA sequencing and analysis of red blood cell parameters. Gap-PCR and PCR-reverse dot blotting (PCR-RDB) were used for analyzing the thalassemia genes., Results: Thirty one cases of Hb J-Bangkok were identified, all of which were heterozygotes. The hematological phenotype index (Hb, mean corpuscular volume, mean corpuscular hemoglobin, Hb J-Bangkok, Hb A 2 ) for male carriers of Hb J-Bangkok were (158±13.0) g/L, (90.1±2.3) fL, (31.1±2.5) pg, (51.3±0.7)% and (2.5±0.1)%, those for female carriers were (124±9.3) g/L, (93.3±4.9) fL, (31.1±1.6) pg, (50.9±1.1)% and (2.6±0.2)%, those for Hb J-Bangkok and an α 3.7 deletion were 124 g/L, 82.1 fL, 26.1 pg, 49.4% and 2.4%, those for Hb J-Bangkok and -- SEA deletion were (120±14.1) g/L, (67.7±5.7) fL, (20.5±2.6) pg, (50.1±1.9)% and (2.1±0.4)%, and those for Hb J-Bangkok and β-thalassemia-related variants were (134±11.3) g/L, (71.6±0.9) fL, (21.7±1.0) pg, (92.7±0.6)%, (5.5±0.8)%. No Hb A was found among the Hb J-Bangkok and concomitant β-thalassemia carriers., Conclusion: Hb J-Bangkok heterozygotes have normal hematological phenotypes, though they may show different hematological characteristics when concomitant with different types of thalassemia, for which genetic counseling should be provided accordingly.

Objective: To accelerate the formation of nisin through overexpressing 6-phosphofructokinase gene pfk in nisin-producer Lactococcus lactis N8., Methods: The genes of pfk and pkaC encoding the catalytic subunit of cAMP-dependent protein kinase were cloned into the vector pMG36e andtransformed into L. lactis N8, resulting in the recombinant strain L. lactis N8-pMG36e-pfk-pkaC. Several biochemical and physological factors, including growth profiles, activity of 6-phosphofructokinase, expression of nisA , antibacterial activity of supernatants and nisin titer, were monitored to investigate the differences between the recombinant strain and the parental strain., Results: No significant difference was observed with respect to the growth patterns of the recombinant strain and the wild type. As expected, the biological activity of PFK in recombinant strain was increased for all examined samples. Correspondingly, the yield of nisin was increased by 20% in the recombinant strain after fermentation for 10 hours, which could be attributed to the accelerated biosynthesis of nisin. As a result, the fermentation cycle was reduced about 2 hours. Meanwhile, different concentration of glucose did not affect the formation of nisin., Conclusion: The overexpression of pfk and pkaC genes in the nisin-producer strain can effectively accelerate nisin biosynthesis.

Objective: Pseudomonas aeruginosa is an opportunistic pathogen responsible for a wide range of acute and chronic infections. When growing in the host, it secrets a lot of virulence factors including elastase. This work aimed to explore the genes involved in hydrolyzing ability of Pseudomonas aeruginosa towards elastin., Methods: We performed a transposon mutagenesis analysis of P. aeruginosa PA68 to identify candidate genes involved in elastin hydrolysis. We also monitored the promoter activity of the lasB, a gene encoding the elastase, in the mutants and the wild-type by introducing a Pl(asB-)lacZ transcriptional fusion., Results: Four mutants with altered levels of elastase production were isolated (elastase activity relative to wild-type was shown in parenthesis): 10 (51%), 17 (131%), 27 (8%) and 84 (13%). Locations of the transposon were mapped to the genome lasA, galU, xcpZ and ptsP, respectively. The results of the lasB promoter's activity were consistent with the elastase activity data (fbetagalactosidase activity relative to wild-type was shown in parenthesis): 10(75%), 17(201%), 27(54%) and 84(7%)., Conclusion: Taken together, the data build up a connection of these four genes with elastase production. This is the first report that gene galU and ptsP may be employed in the regulation of the biosynthesis of elastase.

Objective: To compare the role of dissolving sputum and anti-inflammation of "Mao Ju Hong" (MJH) and "Guang Ju Hong" (GJH)., Method: Using phenolsulfonphthalein method and dimethyl benzene method, the roles of dissolving sputum and anti-inflammation of MJH and GJH were studied., Result: The comparison between the same dosage MJH and GJH showed the result had significant dissimilarity, the role intensity of MJH was bigger than that of GJH., Conclusion: The quality of MJH is better than GJH at the angle of pharmacodynamics. It is coincident with the traditional opinion that the genuine material is good.

Objective: To explore the changes of soluble interleukin-2 receptor(sIL-2R) in serum and cerebrospinal fluid (CSF) of patients with delayed encephalopathy after acute carbon monoxide poisoning (DEACMP)., Methods: There were 31 patients with DEACMP, 32 patients with other encephalopathy and 31 controls in this study. The levels of sIL-2R in serum and CSF were detected by ELISA., Results: Serum sIL-2R in patients with DEACMP[(329.21 +/- 160.99)U/ml] was significantly higher than that in control[(115.67 +/- 89.58) U/ml, P < 0.05)], but not significantly different from that in the other encephalopathy group[(367.50 +/- 123.14) U/ml, P > 0.05)]. CSF sIL-2R in patients with DEACMP[(54.48 +/- 43.04) U/ml] measured a little before discharge was significantly lower than that in patients with the other encephalopathy[(110.24 +/- 76.56) U/ml, P < 0.05)], but not significantly different from that in the control group[(34.96 +/- 22.70)U/ml, P > 0.05)]. At the pre-discharged period, CSF sIL-2R in patients with DEACMP[(100.26 +/- 93.65) U/ml] was significantly higher than that at the early stage of hospitalization[(52.28 +/- 43.31) U/ml, P < 0.05)]. No significant difference in serum sIL-2R was found between early stage of hospitalization[(338.34 +/- 161.53) U/ml] and pre-discharge [(351.31 +/- 175.93) U/ml, P > 0.05)]., Conclusion: The occurrence of DEACMP may be related with immunopathological damage. The sIL-2R levels in serum and CSF may give information about the state of immunological function of the patients with DEACMP and may contribute to determining the patient's condition and prognosis.