Denitrification plays an important role in wastewater treatment systems for the reason that the nitrate or nitrite was reduced, and some gases such as NO, N_2O or N_2 were released. The application of denitrification in wastewater, the mechanism of denitrification, and the effect factors of denitrification were introduced in this paper. The communities of Denitrifying bacteria, and some key enzymes of denitrification were also introduced. The discovery of aerobic denitrifying bacteria, autotrophic denitrifying bacteria, and denitrifying Phosphorus-removing Bacteria were also mentioned in this paper.

OBJECTIVETo study the characteristics of changes of LDH enzyme patterns of mice under slight hypoxia.

METHODSMice treated with artificial hypoxia, various tissues were made for the test of LDH enzymatic activity by the specific staining technique. LDH (1-5) relative percentage enzymatic activity (RPEA) were measured with CS-910 dual-wavelength thin layer chromatography scanner.

RESULTSThe RPEA of LDH isozymes of various tissues after slight hypoxia shifted to the isozymes LDH1 and LDH2, whose principal subunits are H subunits, and the RPEA of LDH1 (H4), LDH2 (H3M) increased, while RPEA of LDH5 (M4) in various tissues decreased prominently except the cardiac muscle, and that of LDH4 (HM3) decreased as well. After polyacrylamide gel electrophoresis (PAGE) of the hypoxia treated cardiac muscle specimen was made, activity subbands originated regularly in the isoyme patterns of LDH, with the regularity of LDH1 (0 subband), LDH2 (0-1 subbands), LDH3 (0-2 subbands), LDH4 (1-3 subbands), LDH5 (2-4 subbands). After adding appropriate amount of NAD+ to the hypoxia treated cardiac muscle specimen, PAGE showed the subbands of four isoymes (LDH2-LDH5) reduced or even totally disappeared in the isozyme patterns.

CONCLUSIONSThe negative feedback regulation of coenzymization and decoenzymization of LDH isozymes is one of the mouse stress responses to slight hypoxia.

Animals ; Hindlimb ; enzymology ; Hypoxia ; enzymology ; Isoenzymes ; metabolism ; L-Lactate Dehydrogenase ; classification ; metabolism ; Liver ; enzymology ; Mice ; Muscles ; enzymology ; Myocardium ; enzymology ; Random Allocation

ObjectiveTo conduct a molecular epidemiological study on human metapneumovirus (hMPV) among pediatric patients in Guangzhou. MethodsA total of 1 840 clinical specimens were obtained from pediatric patients with respiratory infections in Guangzhou Women and Children' s Medical Center in 2010.hMPV was detected by real-time TaqMan RT-PCR in clinical specimens.F gene was amplified and the PCR-products were directly sequenced. ResultsIn 1 840 clinical specimens, 66 werehMPV-positive with a positive rate of 3.59％. hMPV was detected in all specimens except those collected in September and October, and the highest positive hMPV rate occurred in April (6.09％). The F genes of 3 randomly selected strains and hMPVgz01 ( isolated in 2008) were compared with subgroups A1, A2, B1,B2 and C, and the highest homology was with BJ1887 strain of genotype A2b (97％). The F genes of the randomly selected strains and hMPVgz01 were 99％ identical to each other. Sequences and phylogenetics analysis revealed that the epidemical strain in Guangzhou belonged to genotype A2b. ConclusionhMPV is prevalent in spring and summer among children in Guangzhou, and A2b is the predominant genotype.

In China, more than half of heart failure patients are ischemic heart failure patients. And a large proportion of left ventricular assist device implantation patients are also ischemic heart failure patients. However, left ventricular assist device implantation in ischemic heart failure patients is facing with problems such as patient screening, coronary artery disease, small left ventricle, mitral insufficiency, and ventricular aneurysm. There are only a few retrospective studies with small sample sizes abroad trying to provide solutions to these problems. While there is a lack of systematic understanding of this issue in China. Therefore, we provide an overview of the application and progress of left ventricular assist devices in ischemic heart failure patients, aiming to help clinicians have a comprehensive understanding of this issue and provide some guidance.

With the development of information technology, the massive growth of pharmaceutical electronic data and the significant increase in the reports of drug adverse event reports have brought great challenges to pharmacovigilance research. Data mining techniques can automatically extract the risk signals of adverse drug reaction from real-world data. Therefore, efficient data mining of massive adverse event reporting is a necessary measure to realize the automatic detection of adverse drug reactions. By introducing the current major large-scale adverse drug event reporting databases and related data mining methods, this study reviews the application and limitations of adverse drug reaction data mining technology in pharmacovigilance, which provides reference for pharmacovigilance-related institutions and researchers.

Objective To compare the perioperative renal function changes in patients undergoing heart transplantation (HT) and left ventricular assist device (LVAD) implantation. Methods Patients with end-stage heart failure who underwent surgical treatment at Beijing Anzhen Hospital, Capital Medical University from January 2019 to April 2024 were included. According to the surgical method, patients were divided into a HT group and a LVAD group, and the estimated glomerular filtration rate (eGFR) of patients before surgery and postoperative 1, 7, 30, 60 days was compared between the two groups. The patients with preoperative renal dysfunction were subdivided into subgroups for comparison of eGFR changes before surgery and 30 days after surgery between the two groups. Results A total of 112 patients were enrolled. There were 78 patients in the HT group, including 61 males and 17 females, aged (44.42±18.51) years. There were 34 patients in the LVAD group, including 30 males and 4 females, aged (54.94±11.37) years. Compared with the HT group, the average age of patients in the LVAD group was greater (P<0.001), body mass index was higher (P=0.008), preoperative eGFR was lower (P=0.009), and the proportions of smokers (P=0.017), alcohol drinkers (P=0.041), and diabetes mellitus (P=0.028) patients were higher. Among patients with preoperative renal dysfunction [eGFR<90 mL/(min·1.73 m2)], compared with the HT group, the postoperative eGFR of the LVAD group was significantly higher than that of the HT group, and it was significantly increased compared with that before surgery; the postoperative eGFR of the HT group was comparable to that before surgery, and more than half of the patients had a lower eGFR than before surgery. Among patients with preoperative renal dysfunction, 11 patients in the HT group received continuous renal replacement therapy, and 8 died early; 2 patients in the LVAD group received continuous renal replacement therapy, and 1 died early. Conclusion For end-stage heart failure patients with combined renal dysfunction, compared with HT, LVAD implantation enables patients to obtain better renal function benefits.