[Evaluation of Organic Matter Release and Economy for Various Pretreatments of Sewage Sludge].

Mechanical, chemical, and biological methods are always used to pretreat sewage sludge. To determine which pretreatment can release more organic matter from sewage sludge, and therefore, make it more economical, mechanical pretreatment (ultrasonic treatment at 20 kHz), chemical pretreatment (pH 10), and biological pretreatment (anaerobic conditions at 70℃) were compared. Results showed that all three pretreatments increased the organic matter release of sewage sludge; the initial total soluble protein and carbohydrate concentration of which was only 418.9 mg·L-1 (cal. as COD) and the DNA content was 18.1 mg·L-1. However, the pH 10 and anaerobic (70℃) pretreatments resulted in a greater organic release than the ultrasonic (20 kHz) pretreatment, with total soluble protein and carbohydrate concentrations of 7516.0 mg·L-1 and 7892.5 mg·L-1, and DNA contents of 1343.3 mg·L-1 and 1766.1 mg·L-1, respectively. Flow cytometry was adopted to assess cell morphology. The cell mortality rates of sludge after pretreatment accounted for 61.6%, 59.9%, and 34.5% respectively, which was improved by 45.6% (at pH 10), 43.9% (under anaerobic conditions at 70℃), and 18.5% (with ultrasonic pretreatment at 20 kHz) compared with raw sewage sludge. At the same time, organic matter removal ratios of sludge after pretreatment were 19.1% (at pH 10), 13.8% (under anaerobic conditions at 70℃), and 7.6% (with ultrasonic pretreatment at 20 kHz). Moreover, the pretreatment of per liter sludge at pH 10 saved 28.5% and 124.1% more than ultrasonic pretreatment (20 kHz) and anaerobic (70℃) pretreatment. Taking both organic matter release and economic analysis into consideration, the chemical method of pretreatment (at pH 10) was identified as the best option.

Prevalence of human papillomavirus and Epstein-Barr virus DNA in Chinese children with tonsillar and/or adenoidal hypertrophy.

Tonsillar and adenoidal hypertrophy are prevalent otolaryngologic disorders in children, but their pathogenesis is largely unknown. The presence of human papillomavirus (HPV) and Epstein-Barr virus (EBV) DNA in 146 tonsil and/or adenoid tissue specimens from 104 Chinese children with tonsillar and/or adenoidal hypertrophy were screened using flow-through hybridization gene-chip technology and real-time fluorescence-based quantitative PCR. Then, the relationships between the prevalence of the viruses and other clinical characteristics of tonsillar and/or adenoidal hypertrophy were analyzed. No patient had HPV DNA. EBV DNA was detected in 19/42 (45.2%) tonsil tissues and 72/104 (69.2%) adenoid tissue specimens (P < 0.05). EBV DNA was not related to the patients' age, gender, disease course, or nationality, but children positive for EBV were less likely to snore; 14/15 (93.3%) patients who did not snore and 59/89 (66.3%) patients who snored were EBV positive. EBV DNA, but not HPV DNA was detected in Chinese children with tonsillar and/or adenoidal hypertrophy. Adenoid tissues might more susceptible than tonsil tissues to EBV infection. In addition, EBV infection did not aggravate snoring in patients with tonsillar and/or adenoidal hypertrophy.

Distribution of 37 human papillomavirus types in parotid gland tumor tissues.

Human papillomavirus (HPV) infection has been shown to be associated with human tumorigenesis. The aim of the present study was to demonstrate the association between HPV infection and parotid gland tumors. Paraffin-embedded tissue sections from 59 cases of parotid gland tumors and 20 normal oral mucosa were subjected to DNA extraction and flow-through hybridization and gene chip technology to detect infection of 37 HPV types. The HPV-positive rate was 57.6% in parotid gland tumor paraffin-embedded tissue specimens, whereas, the normal control group was negative for HPV. The HPV-positive rate was 59.6% in parotid gland benign tumor tissues and 42.9% in parotid malignant tissues. HPV infection in parotid gland tumors was dominated by the high-risk subtypes (80.7%), which mainly consisted of HPV 16, 18 and 52 (61.4%). In addition, parotid gland tumor tissues were found to be infected by multiple or single types of HPV, but were predominantly infected by mixed HPV types. In this study, we found that the occurrence of parotid gland tumor is correlated with HPV infection.

Human papillomavirus infection in nasal polyps in a Chinese population.

In order to determine the prevalence and genotype distribution of human papillomavirus (HPV) infection in patients with nasal polyps, a total of 204 patients with nasal polyps and 36 healthy controls were recruited for this study. Genomic DNA was extracted from paraffin-embedded tissue sections. HPV DNA genotyping was achieved by a flow-through hybridization and gene-chip method. HPV-positive infection was identified in 82 of 204 (40.2 %) patients, while HPV DNA was not found in healthy controls (P<0.05). Genotyping analysis showed that low-risk HPV genotype 11 was the most prevalent type of HPV in nasal polyps (45.28 %). Both single and multiple HPV genotype infections were found in these HPV-positive cases, although most (74.39 %) were infected with a single genotype. In addition, there was no correlation between HPV infection or HPV subtypes and the clinicopathological characteristics of patients, such as age, gender, number of surgery and disease course. The data from our study clearly demonstrated that HPV infection was associated with nasal polyps. Both high-risk HPV and low-risk HPV (LR-HPV) genotypes were identified in nasal polyp tissues, and LR-HPV-11 was the most prevalent type. Future research will explore the association of HPV infection with the development and progression of nasal polyps.

[Evaluation of TTC and INT-electron transport system activity tests for heavy metal inhibition of activated sludge].

The effects of Cu2+, Zn2+, Cd2+, Hg2+, Ni2+, Pb2+ and Ag+ on TTC and INT-electron transport system activity are studied and the sensitivities of TTC and INT-electron transport system activity to seven tested heavy metals are compared to evaluate both the parameters for assessing heavy metal inhibition of activated sludge. The median inhibitory concentration (IC50) of seven tested heavy metals measured via TTC-electron transport system activity is less than that measured via INT-electron transport system activity, which indicates that the INT-electron transport system activity is less sensitive to heavy metals than the TTC-electron transport system activity. The ranking of tested heavy metals in order of decreasing toxicity based on TTC-electron transport system activity was Hg2+, Cd2+, Cu2+, Ag+, Zn2+, Ni2+ and Pb2+ , and the ranking based on INT-electron transport system activity was Hg2+, Ag+, Cu2+, Cd2+, Zn2+, Ni2+ and Pb2+.