[Spatial Distribution Characteristics and Source Apportionment of Soil PAHs in Shizuishan City Based on GIS and PMF Model].

With the acceleration of urbanization and industrialization, the content and pollution of polycyclic aromatic hydrocarbons (PAHs) in urban soils have been sources of widespread concern. Taking Shizuishan City as an example, the spatial distribution characteristics of PAHs in 156 surface soil samples (0-20 cm) from eight urban functional areas were analyzed. Single factor and Nemero composite indices, as well as a lifetime cancer risk increment model were used to evaluate PAHs pollution in soils. The sources of PAHs were analyzed using the positive matrix factorization (PMF) model. The results showed that the mean value of PAHs in the surface soil of Shizuishan City was 489.82 ng·g-1 and the coefficient of variation of 15 PAHs except for Pyr were more than 100%, indicating strong variation. The PAH contents of urban surface soils in different functional areas showed the following:traffic area (1217.61 ng·g-1) > industrial area (809.58 ng·g-1) > park (273.66 ng·g-1) > cultural and educational area (268.18 ng·g-1) > commercial area (240.05 ng·g-1) > agricultural area (226.81 ng·g-1) > medical area (211.90 ng·g-1) > residential area (183.49 ng·g-1). The Nemero composite index showed that 82.58% of the samples had no pollution, and the proportion of slight, mild, and moderate pollution were 6.45%, 4.52%, and 0.65%, respectively. Only 5.8% of the samples had serious pollution. The results of health risk assessment showed that skin contact and ingestion were the main routes of PAH exposure in soil, and the health risk was acceptable. Source analysis showed that the main sources of PAHs in Shizuishan City were traffic emissions, coal combustion, mixed biomass/heavy oil combustion, and oil sources, with contribution rates of 10.5%, 36.6%, 50.3%, and 2.6% respectively, and most of the high values were distributed in industrial or coal production areas. These results could provide reference for the study of soil pollution in industrial cities, and play an important role in preventing soil pollution, ensuring the environmental quality of the soil and human health and safety.

Decreased expression of surfactant protein C in lung tissue of chronic obstructive pulmonary disease rats / 基础医学与临床

Objective To study the role of surfactant protein C ( SP-C) in rat lung of chronic obstructive pulmonary disease (COPD).Methods Forty healthy conventional Sprague-Dawley (SD) rats were randomly divided into four groups , normal control group ( control group ) , smoke exposure group ( smoking group ) , lipopolysaccharide group (LPS group), smoke exposure +Lipopolysaccharide group (COPD group).The arterial partial pressure oxygen (PaO2) and arterial partial pressure of carbon dioxide pathological (PaCO2) were detected.The ultrastructure of lung tissue was observed by transmission electron microscope .Enzyme-linked immuno sorbent assay (ELISA) were performed to determine protein expression of SP-C in lung and bronchoalveolar lavage fluid ( BALF).RT-qPCR were performed to determine mRNA expression of SP-C in lung.Results Compared with control group , smoking group and LPS group, the PaO2 of COPD group was obviously lower , the PaCO2 of COPD group was obviously higher;the ultrastructure and histological analysis of lung tissues showed chronic inflammatory injury ; Compared with control group , the expression of SP-C protein in was reduced , as well as SP-C mRNA expression .Conclusions The expression of SP-C in lung of rats COPD model is down-regulated.SP-C may be involved in COPD .

Community-onset bacteremia in kidney transplant recipients: The recipients fare well in terms of mortality and kidney injury.

BACKGROUND: Bloodstream infection is not uncommon in kidney transplant recipients (KTRs) and is associated with mortality, graft loss, and increased medical expenses. Whether these septic patients are more vulnerable to serious complications, resistant strains, or worse clinical outcomes than other patient groups in the community-onset settings remains undetermined. METHODS: A retrospective study was conducted at a medical center in southern Taiwan. Community-onset bacteremia in the KTRs and a control population at the emergency department were identified. Demographic data, clinical characteristics, bacteremic pathogens, antimicrobial resistance, and clinical outcomes were recorded. RESULTS: Forty-one bacteremic episodes in the KTRs and 82 episodes in control patients were studied. The KTR group had younger age, fewer malignancies, more urosepsis (61% vs. 22%, p = 0.004), and fewer biliary tract infections (0% vs. 13.4%, p = 0.018). Escherichia coli was the most commonly isolated pathogen in both the groups (51.2% and 41.5%, respectively). No Klebsiella pneumoniae bacteremia was noted in the KTRs, compared with 14 (17.1%) episodes in the control group (p = 0.010). Antimicrobial resistance profiles of bacteremic pathogens were similar (all p > 0.6). The KTRs with community-onset bacteremia did not have a worse outcome (in-hospital mortality rate: 2.4% vs. 10%, p = 0.172) nor more incomplete resolution of kidney injury after acute kidney injury events (21.1% vs. 25%, p > 0.99) than the control group. CONCLUSION: KTRs with community-onset bacteremia did not fare worse in terms of clinical outcome and kidney injury.

Bacteremic pneumonia caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: Appropriateness of empirical treatment matters.

BACKGROUND: Clinical information about bacteremic pneumonia caused by extended-spectrum beta-lactamase (ESBL)-producing organism is limited. METHODS: A retrospective study was conducted at two medical centers in Taiwan. From May 2002 to August 2010, clinical information and outcome of adults with bacteremic pneumonia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae were analyzed. The primary outcome is the 30-day mortality. RESULTS: A total of 111 patients with bacteremic pneumonia caused by E. coli (37 patients, 33.3%) and K. pneumoniae (74, 66.7%) were identified. Their mean age was 69.2 years and 51.4% were male patients. Fifty-seven (51.3%) episodes were classified as hospital-acquired infections, 19 (17.1%) as health-care-associated infections, and four (3.6%) as community-acquired infections. Fifty-one (45.9%) patients received appropriate empiric antimicrobial therapy. The 30-day mortality rate was 40.5% (45 patients). In the multivariate analysis, several independent risk factors, including rapidly fatal underlying disease [odds ratio (OR), 5.75; 95% confidence interval (CI), 1.54-21.48; p = 0.009], severe sepsis (OR, 4.84; 95% CI, 1.55-15.14; p = 0.007), critical illness (OR, 4.28; 95% CI, 1.35-13.57; p = 0.013), and receipt of appropriate empirical therapy (OR, 0.19; 95% CI, 0.07-0.55; p = 0.002), were associated with 30-day mortality. The survival analysis consistently found that individuals with appropriate empiric therapy had a higher survival rate (log-rank test, p < 0.001). CONCLUSION: ESBL-producing bacteremic pneumonia, especially health-care-associated infections, often occurred in adults with comorbidities. Appropriate empirical therapy was associated with a favorable outcome.

Pathway engineering results the altered polyhydroxyalkanoates composition in recombinant Escherichia coli.

To efficiently produce short-chain-length-medium-chain-length polyhydroxyalkanoates copolymer from substrate mixture containing sugars and/or fatty acids, fadA gene mutant was constructed in Escherichia coli DH5α phosphotransferase system (PTS) disrupted strain. Plasmids pCJY02, pBHR68 and pBHR71 were separately introduced into E. coli DH5α (ΔptsG, ΔFadA) by transformation, then the recombinants were cultivated in the medium containing glucose and/or decanoate as carbon resource, respectively. When cultivated in the medium containing decanoate, only pCJY02-harboring recombinant was able to accumulate SCL-MCL PHAs consisting of 3HB, 3HHx, 3HO and 3HD with mol ratios: 43.2:12.8:10.3:33.6. The copolymer content was 1.90wt% with 2.69gL(-1) cell dry weight. When cultivated in the medium containing both decanoate and glucose, the recombinant was found to utilize the mixture of glucose and fatty acids and accumulate SCL-MCL PHAs copolymer consisting of 3HB, 3HHx, 3HO and 3HD with mol ratios: 83.4:4.0:5.6:7.0. About 4.90gL(-1) cell dry weight was harvested and total PHAs content was 7.3wt% of CDW. This result indicated that the low-substrate-specificity PHA synthase PhaC2(Ps) endued hosts with the capability of synthesizing PHA copolymers, and the monomer composition of the synthesized PHA could be modulated by controlling the addition of carbon sources and by modifying metabolic pathways in the hosts.

Survey on prevalence of atopic dermatitis in 0 - 6 year-old children in Tianjin / 中华皮肤科杂志

Objective To investigate the prevalence of and predisposing factors of atopic dermatitis (AD ) in 0 - 6 year-old children in rural and urban area of Tianjin. Methods The subjects were chosen by cluster sampling from kindergartens in Tianjin's urban and rural districts. Questionnaires were designed based on the International Study of Asthma and Allergies in Children (ISAAC ) and distributed to the children's parents via the teachers. Results In this survey, 3 749 questionaires were returned, of which 3 708 were valid. The response rate was 82.7% in total, 79.3% in the rural area, and 84.9% in the urban area. The age and gender distributions were similar in the urban and rural area. The prevalence rate of AD in these children was 2.9% in total, and it was higher in the urban area than in the rural area (3.5% vs 2.4%, x2 = 3.98, P