[Application of synthetic MRI in predicting isocitrate dehydrogenase 1 genotypes in gliomas]

This study analyzed the clinical and imaging data of 81 glioma patients who underwent brain synthetic MRI and diffusion weighted imaging (DWI) examination in the General Hospital of Ningxia Medical University from August 2020 to September 2021 to explore the value of synthetic MRI relaxation quantitative value in predicting the genotype of isocitrate dehydrogenase 1 (IDH1) in gliomas. There were 44 males and 37 females, those patients with an aged 50.0 (36.5, 59.0) years. The tumor pre-T1, pre-T2, pre-PD, post-T1 and ADC values were obtained by outlining the region of interest (ROI). Univariate analysis was used to compare the differences of parameter values between groups, and the receiver operating characteristic was used to evaluate the diagnostic efficacy of each parameter value in predicting glioma IDH1 genotype. The results showed that the pre-T1 and pre-PD values [M (Q1, Q3)] of IDH1m glioma were lower than those of IDH1w glioma [1 462.75 (1 306.41, 1 567.75) ms vs 1 532.83 (1 434.67, 1 617.67) ms, 84.18 (82.28, 86.41) pu vs 85.85 (84.65, 86.90) pu] (all P<0.05). The post-T1 and ADC values of IDH1m glioma were higher than those of IDH1w glioma [1 054.50 (631.92, 1 262.63) ms vs 669.67 (535.17, 823.33) ms, 1.20 (0.86, 1.35) ×10-3 mm2/s vs 0.80 (0.76, 0.93) ×10-3 mm2/s] (all P<0.05). The AUC of the combined model (pre-T1+pre-PD+post-T1+ADC+Age) is 0.828 (95%CI:0.729-0.903). Synthetic MRI relaxation quantitative values are helpful to distinguish IDH1 genotypes in glioma. The diagnostic efficacy of the multi-parameter combined model based on pre-T1, pre-PD, post-T1, ADC, and age is better than that of the single parameter, and it can be used as an effective strategy to improve the differential diagnosis ability of gliomas molecular markers.

[Thoracoscopic laparoscopy-assisted Ivor-Lewis resection of esophagogastric junction cancer]

Objective: To investigate the outcome of patients with esophagogastric junction cancer undergoing thoracoscopic laparoscopy-assisted Ivor-Lewis resection. Methods: Eighty-four patients who were diagnosed with esophagogastric junction cancer and underwent Ivor-Lewis resection assisted by thoracoscopic laparoscopy at the National Cancer Center from October 2019 to April 2022 were collected. The neoadjuvant treatment mode, surgical safety and clinicopathological characteristics were analyzed. Results: Siewert type Ⅱ (92.8%) and adenocarcinoma (95.2%) were predominant in the cases. A total of 2 774 lymph nodes were dissected in 84 patients. The average number was 33 per case, and the median was 31. Lymph node metastasis was found in 45 patients, and the lymph node metastasis rate was 53.6% (45/84). The total number of lymph node metastasis was 294, and the degree of lymph node metastasis was 10.6%(294/2 774). Among them, abdominal lymph nodes (100%, 45/45) were more likely to metastasize than thoracic lymph nodes (13.3%, 6/45). Sixty-eight patients received neoadjuvant therapy before surgery, and nine patients achieved pathological complete remission (pCR) (13.2%, 9/68). Eighty-three patients had negative surgical margins and underwent R0 resection (98.8%, 83/84). One patient, the intraoperative frozen pathology suggested resection margin was negative, while vascular tumor thrombus was seen on the postoperative pathological margin, R1 resection was performed (1.2%, 1/84). The average operation time of the 84 patients was 234.5 (199.3, 275.0) minutes, and the intraoperative blood loss was 90 (80, 100) ml. One case of intraoperative blood transfusion, one case of postoperative transfer to ICU ward, two cases of postoperative anastomotic leakage, one case of pleural effusion requiring catheter drainage, one case of small intestinal hernia with 12mm poke hole, no postoperative intestinal obstruction, chyle leakage and other complications were observed. The number of deaths within 30 days after surgery was 0. Number of lymph nodes dissection, operation duration, and intraoperative blood loss were not related to whether neoadjuvant therapy was performed (P>0.05). Preoperative neoadjuvant chemotherapy combined with radiotherapy or immunotherapy was not related to whether postoperative pathology achieved pCR (P>0.05). Conclusion: Laparoscopic-assisted Ivor-Lewis surgery for esophagogastric junction cancer has a low incidence of intraoperative and postoperative complications, high safety, wide range of lymph node dissection, and sufficient margin length, which is worthy of clinical promotion.

Effects of tillage and cropping sequences on crop production and environmental benefits in the North China Plain

The ever-increasing trend of greenhouse gas (GHG) emissions is accelerating global warming and threatening food security. Environmental benefits and sustainable food production must be pursued locally and globally. Thus, a field experiment was conducted in 2015 to understand how to balance the trade-offs between agronomic productivity and environment quality in the North China Plain (NCP). Eight treatments consisted of two factors, i.e., (1) tillage practices: rotary tillage (RT) and no-till (NT), and (2) cropping sequences (CS): maize-wheat-soybean-wheat (MWSW), soybean-wheat-maize-wheat (SWMW), soybean-wheat (SW), and maize-wheat (MW). The economic and environmental benefits were evaluated by multiple indicators including the carbon footprint (CF), maize equivalent economic yield (MEEY), energy yield (EY), and carbon sustainability index (CSI). Compared with NT, RT increased the EY and MEEY, but emitted 9.4% higher GHGs. Among different CSs, no significant reduction was observed in CF. The lowest (2.0 Mg CO₂-eq ha^-1 year^-1) and the highest (5.6 Mg CO₂-eq ha^-1 year^-1) CF values were observed under MW and SWMW, respectively. However, CSs with soybean enhanced MEEY and the net revenue due to their higher price compared to that of MW. Although the highest CSI was observed under RT-MW, soybean-based crop rotation could offset the decline in CSI under NT when compared to that for RT. These findings suggest that conservation agriculture (CA) could enhance the balance in trade-offs between economic and environmental benefits. Additional research is needed on how to achieve high crop production by establishing a highly efficient CA system in the NCP.

Improving soil aggregates stability and soil organic carbon sequestration by no-till and legume-based crop rotations in the North China Plain

Conservation agriculture (CA) has been adopted worldwide on about 200 Mha to enhance soil organic carbon (SOC) for mitigating climate change. However, as a crucial mechanism to sequester SOC, how the protection of aggregates responds to the interaction between no-till and crop rotations (two principles of CA) remains unknown. Thus, a field experiment with six treatments [e.g., no-till or rotary tillage under the maize-wheat-soybean-wheat system (NT-MWSW, RT-MWSW), no-till or rotary tillage under the maize-wheat system (NT-MW, RT-MW), and no-till or rotary tillage under the soybean-wheat system (NT-SW, RT-SW)] was conducted from June 2018 to June 2021 in the North China Plain (NCP) to assess their effects on aggregation and SOC. Results indicated that macroaggregates (> 0.25 mm) were the main contributors to the soil carbon (C) pool, comprised 64.7-87.3 % of aggregates, and encompassed 64.9-73.1 % of the SOC stock. NT increased not only the proportion of macroaggregates but also aggregate stability (i.e., mean weight diameter and geometric mean diameter). Significant positive effects from legumes were observed under NT. SW increased by 13.6 % macroaggregate-associated SOC under NT in 0-20 cm compared to that under MW. Additionally, the conversion rate of straw C input under NT-SW was higher than that in other treatments, augmenting it by 9.4-21.9 %. This may be attributed to the higher macroaggregate total nitrogen (increased by 1.7-15.9 %) in 0-10 cm under legume-based crop rotations compared to that under MW, resulting in lower C: N ratios, which promoted the decomposition of straw. Furthermore, the total potential mineralization of macroaggregates under NT legume-based crop rotations was 3.0-16.0 % higher than that of MW. Thus, a legume-based NT system can significantly improve soil macro-aggregation, increase the conversion rate of straw C input, and reduce C loss, which can be a viable practice to enhance SOC sequestration capacity under CA in the NCP.

Sieving soil before incubation experiments overestimates carbon mineralization but underestimates temperature sensitivity

The sensitivity of soil organic carbon (SOC) mineralization to temperature could affect the future atmospheric CO₂ levels under global warming. Sieved soils are widely used to assess SOC mineralization and its temperature sensitivity (Q₁₀) via laboratory incubation. However, sieved soils cause a temporary increase in mineralization due to the destruction of soil structure, which can affect estimates of SOC mineralization, especially in soils managed with no-till (NT). To identify the effects of soil sieving on SOC mineralization and Q₁₀, soil was collected from an 11-year field experiment under a wheat-maize cropping system managed with a combination of tillage [NT and plow tillage (PT)] and residue [residue returning (RR) and residue removal (R0)]. Soil was either sieved or left in an undisturbed state and incubated at 15 °C and 25 °C. SOC mineralization in sieved soils at 25 °C was 47.28 g C kg^-1 SOC, 160.1% higher than SOC mineralization in undisturbed soils (P < 0.05). Interestingly, Q₁₀ values in sieved soils were 1.29, 77.6% lower than Q₁₀ in undisturbed soils (P < 0.05). Highly significant correlations (P < 0.01) were observed between sieved and undisturbed soils for SOC mineralization (r = 0.85-0.98) and Q₁₀ (r = 0.78-0.87). Soil macro-aggregates had lower SOC mineralization by 6.1-21.9%, but higher Q₁₀ values by 4.7-6.5% compared with micro-aggregates, contributing to lower mineralization and higher Q₁₀ under NT and RR. Furthermore, structure equation and random forest modelling showed that increased SOC contents in NT and RR could not only reduce SOC mineralization, but also constrained the improvement of Q₁₀ in NT and RR. Overall, these results indicated that although sieved soils overestimated SOC mineralization and underestimated Q₁₀ due to the destruction of macro-aggregates, the patterns between treatments were similar and sieving soil for incubation is considered as a suitable approach to evaluate the relative impacts of NT and RR on SOC mineralization and Q₁₀.

Mechanisms of soil organic carbon stability and its response to no-till: A global synthesis and perspective

Mechanisms of soil organic carbon (SOC) stabilization have been widely studied due to their relevance in the global carbon cycle. No-till (NT) has been frequently adopted to sequester SOC; however, limited information is available regarding whether sequestered SOC will be stabilized for long term. Thus, we reviewed the mechanisms affecting SOC stability in NT systems, including the priming effects (PE), molecular structure of SOC, aggregate protection, association with soil minerals, microbial properties, and environmental effects. Although a more steady-state molecular structure of SOC is observed in NT compared with conventional tillage (CT), SOC stability may depend more on physical and chemical protection. On average, NT improves macro-aggregation by 32.7%, and lowers SOC mineralization in macro-aggregates compared with CT. Chemical protection is also important due to the direct adsorption of organic molecules and the enhancement of aggregation by soil minerals. Higher microbial activity in NT could also produce binding agents to promote aggregation and the formation of metal-oxidant organic complexes. Thus, microbial residues could be stabilized in soils over the long term through their attachment to mineral surfaces and entrapment of aggregates under NT. On average, NT reduces SOC mineralization by 18.8% and PE intensities after fresh carbon inputs by 21.0% compared with CT (p < .05). Although higher temperature sensitivity (Q₁₀ ) is observed in NT due to greater Q₁₀ in macro-aggregates, an increase of soil moisture regime in NT could potentially constrain the improvement of Q₁₀ . This review improves process-based understanding of the physical and chemical mechanism of protection that can act, independently or interactively, to enhance SOC preservation. It is concluded that SOC sequestered in NT systems is likely to be stabilized over the long term.

Responses of soil pH to no-till and the factors affecting it: A global meta-analysis

No-till (NT) is a sustainable option because of its benefits in controlling erosion, saving labor, and mitigating climate change. However, a comprehensive assessment of soil pH response to NT is still lacking. Thus, a global meta-analysis was conducted to determine the effects of NT on soil pH and to identify the influential factors and possible consequences based on the analysis of 114 publications. When comparing tillage practices, the results indicated an overall significant decrease by 1.33 ± 0.28% in soil pH under NT than that under conventional tillage (p < .05). Soil texture, NT duration, mean annual temperature (MAT), and initial soil pH are the critical factors affecting soil pH under NT. Specifically, with significant variations among subgroups, when compared to conventional tillage, the soil under NT had lower relative changes in soil pH observed on clay loam soil (-2.44%), long-term implementation (-2.11% for more than 15 years), medium MAT (-1.87% in the range of 8-16℃), neutral soil pH (-2.28% for 6.5 < initial soil pH < 7.5), mean annual precipitation (-1.95% in the range of 600-1200 mm), in topsoil layers (-2.03% for 0-20 cm), with crop rotation (-1.98%), N fertilizer input (the same for NT and conventional tillage) of 100-200 kg N ha^-1 (-1.83%), or crop residue retention (-1.52%). Changes in organic matter decomposition under undisturbed soil and with crop residue retention might lead to a higher concentration of H⁺ and lower of basic cations (i.e., calcium, magnesium, and potassium), which decrease the soil pH, and consequently, impact nutrient dynamics (i.e., soil phosphorus) in the surface layer under NT. Furthermore, soil acidification may be aggravated by NT within site-specific conditions and improper fertilizer and crop residue management and consequently leading to adverse effects on soil nutrient availability. Thus, there is a need to identify strategies to ameliorate soil acidification under NT to minimize the adverse consequences.

Germline Variants and Genetic Interactions of Several EMT Regulatory Genes Increase the Risk of HBV-Related Hepatocellular Carcinoma

Epithelial-mesenchymal transition (EMT) plays an important role in the development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). We hypothesized that germline variants in the major EMT regulatory genes (SNAIL1, ZEB1, ZEB2, TWIST1) may influence the development of HBV-related HCC. We included 421 cases of HBsAg-positive patients with HCC, 1371 cases of HBsAg-positive subjects without HCC [patients with chronic hepatitis B (CHB) or liver cirrhosis (LC)] and 618 cases of healthy controls in the case-control study. Genotype, allele, and haplotype associations in the major EMT regulatory genes were tested. Environment-gene and gene-gene interactions were analysed using the non-parametric model-free multifactor dimensionality reduction (MDR) method. The SNAIL1rs4647958T>C was associated with a significantly increased risk of both HCC (CT+CC vs. TT: OR=1.559; 95% confidence interval [CI], 1.073-2.264; P=0.020) and CHB+LC (CT+CC vs. TT: OR=1.509; 95% CI, 1.145-1.988; P=0.003). Carriers of the TWIST1rs2285681G>C (genotypes CT+CC) had an increased risk of HCC (CG+CC vs. GG: OR=1.407; 95% CI, 1.065-1.858; P=0.016). The ZEB2rs3806475T>C was associated with significantly increased risk of both HCC (P _recessive =0.001) and CHB+LC (P _recessive<0.001). The CG haplotype of the rs4647958/rs1543442 haplotype block was associated with significant differences between healthy subjects and HCC patients (P=0.0347). Meanwhile, the CT haplotype of the rs2285681/rs2285682 haplotype block was associated with significant differences between CHB+LC and HCC patients (P=0.0123). In MDR analysis, the combination of TWIST1rs2285681, ZEB2rs3806475, SNAIL1rs4647958 exhibited the most significant association with CHB+LC and Health control in the three-locus model. Our results suggest significant single-gene associations and environment-gene/gene-gene interactions of EMT-related genes with HBV-related HCC.

[Perinatal outcomes on mortality and influencing factors among HIV-infected mothers in Sichuan province]

Objective: To explore the influencing factors on perinatal mortality of pregnant women with HIV infection to reduce the mother-to-child transmission in Sichuan province. Methods: In this study, 4 786 perinatal infants of the HIV-infected pregnant women were included. Related data on perinatal epidemiology was reported by all the 183 medical and health care institutions where the HIV prevention of mother-to-child transmission program was initiated in 2005-2016. Univariate χ(2) test and multivariate logistic regression methods were used to analyze the perinatal mortality outcomes and influencing factors. Results: The overall perinatal mortality rate was 25.7‰ (123/4 786) among HIV-infected pregnant women, with annual downwarding trend (trend χ(2)=32.220, P=0.000). Perinatal mortality rate appeared the highest (χ(2)=4.130, P=0.042), with more fetal deaths and stillbirths and less early neonatal death within 7 days in Liangshan county (χ(2)=29.626, P=0.000). Results from the multivariate logistic regression analysis showed that fewer pregnant numbers would contribute to the, lower perinatal mortality rate (1-2 pregnancies OR=0.417, 95%CI: 0.184-0.943; 3-4 pregnancies OR=0.447, 95%CI: 0.223-0.895). Perinatal deaths were more likely to be prevented if LPV/r protease inhibitor-based triple antiviral therapy was provided (OR=0.530, 95%CI: 0.285- 0.986) or delivery was taken place in the hospital (hospital of municipal-level and above OR=0.222, 95%CI:0.098-0.499; county-level hospital OR=0.282, 95%CI: 0.166-0.480; township-level hospital OR=0.134, 95%CI: 0.031-0.586) among HIV-infected pregnant women. However, premature delivery or neonatal asphyxia would increase the risk of perinatal mortality (premature delivery OR=8.285, 95%CI: 5.073-13.533; neonatal asphyxia OR=9.624, 95%CI: 4.625-20.028). Conclusions: The perinatal mortality rate of HIV-infected pregnant women appeared significantly higher than that in the province or the whole country. Strategies involving LPV/r-based triple antiviral therapy, promotion of hospital delivery, reducing the incidence rates of premature deliveries and neonatal asphyxia, should be strengthened.

[Study on the correlation between prognosis of patients with chronic hepatitis B under interferon treatment and polymorphism of both calcitonin gene related peptide and receptor activity modifying protein 1]

Objective: To analyze the association of two single-nucleotide polymorphisms (SNP) [Calcitonin gene related peptide (CGRP) rs155209 and receptor activity modifying protein 1 (RAMP1) rs3754701] and the prognosis of chronic hepatitis B patients who were under interferon therapy. Methods: A total of 317 patients and their anticoagulant blood samples were collected in this study. The SNPs in the CGRP and region RAMP1 were genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Logistic regression method was used to assess the results from different phenotypic outcomes between cases and controls, after adjusted for sex and age in co-dominant, dominant and recessive genetic models. Results: Data from this study clearly demonstrated the relevance of CGRP rs155209 and RAMP1 rs3754701 with DNA response and ALT response. RAMP1 rs3754701T was strongly associated with both DNA response and ALT response (OR=2.277, 95%CI: 1.386-3.741, P=0.001; OR=1.694, 95%CI: 1.073-2.675, P=0.024). However, CGRP rs155209C was less prone to DNA response and ALT response (OR=0.150, 95%CI: 0.083-0.271, P<0.001; OR=0.583, 95%CI: 0.367-0.925, P=0.022). Conclusions: Results from our study suggested that both RAMP1 rs3754701 and CGRP rs155209 were associated with the prognosis of patients under interferon therapy in Han population, from the northern parts of China while RAMP1 rs3754701T was a protective factor for both ALT response and DNA response, but CGRP rs155209C carriers were less prone to DNA and ALT responses.

[Surgical treatment for esophageal cancer during the outbreak of COVID-19]

Since December 2019, unexplained pneumonia has appeared in Wuhan City, Hubei Province, and a new type of coronavirus infection was confirmed as COVID-19. COVID-19 spread rapidly nationwide and abroad. The COVID-19 has brought huge impacts to all the people and walks of life, especially to the medical and health systems. It has also brought great challenges to the treatment of patients with cancer. Esophageal cancer is a common malignant tumor in China and most of the patients are in the middle and advanced stage when diagnosed, with immunosuppressive and poor prognosis. The selection of surgical procedures and perioperative managements of esophageal cancer require all thoracic surgeons work together to figure out a reasonable system of surgical treatment and emergency response.

Calcitonin gene-related peptide inhibits angiotensin II-induced NADPH oxidase-dependent ROS via the Src/STAT3 signalling pathway

We had previously demonstrated that the calcitonin gene‐related peptide (CGRP) suppresses the oxidative stress and vascular smooth muscle cell (VSMC) proliferation induced by vascular injury. A recent study also indicated that CGRP protects against the onset and development of angiotensin II (Ang II)‐induced hypertension, vascular hypertrophy and oxidative stress. However, the mechanism behind the effects of CGRP on Ang II‐induced oxidative stress is unclear. CGRP significantly suppressed the level of reactive oxygen species (ROS) generated by NADPH oxidase in Ang II‐induced VSMCs. The Ang II‐stimulated activation of both Src and the downstream transcription factor, STAT3, was abrogated by CGRP. However, the antioxidative effect of CGRP was lost following the expression of constitutively activated Src or STAT3. Pre‐treatment with H‐89 or CGRP_8–37 also blocked the CGRP inhibitory effects against Ang II‐induced oxidative stress. Additionally, both in vitro and in vivo analyses show that CGRP treatment inhibited Ang II‐induced VSMC proliferation and hypertrophy, accompanied by a reduction in ROS generation. Collectively, these results demonstrate that CGRP exhibits its antioxidative effect by blocking the Src/STAT3 signalling pathway that is associated with Ang II‐induced VSMC hypertrophy and hyperplasia.

An Azure ACES Early Warning System for Air Quality Index Deteriorating

With the development of industrialization and urbanization, air pollution in many countries has become more serious and has affected people's health. The air quality has been continuously concerned by environmental managers and the public. Therefore, accurate air quality deterioration warning system can avoid health hazards. In this study, an air quality index (AQI) warning system based on Azure cloud computing platform is proposed. The prediction model is based on DFR (Decision Forest Regression), NNR (Neural Network Regression), and LR (Linear Regression) machine learning algorithms. The best algorithm was selected to calculate the 6 pollutants required for the AQI calculation of the air quality monitoring in real time. The experimental results show that the LR algorithm has the best performance, and the method of this study has a good prediction on the AQI index warning for the next one to three hours. Based on the ACES system proposed, it is hoped that it can prevent personal health hazards and help to reduce medical costs in public.

Calcitonin gene-related peptide attenuates angiotensin II-induced ROS-dependent apoptosis in vascular smooth muscle cells by inhibiting the CaMKII/CREB signalling pathway

Apoptosis is associated with various cardiovascular diseases. CGRP exerts a variety of effects within the cardiovascular system, and protects against the onset and development of angiotensin (Ang) II-induced vascular dysfunction and remodelling. However, it is not known whether CGRP has a direct effect on Ang II-induced apoptosis in vascular smooth muscle cells (VSMCs), and the mechanism underlying the anti-apoptotic role remains unclear. In this study, CGRP significantly suppressed reactive oxygen species (ROS) and apoptosis in Ang II-induced VSMCs. In VSMCs pre-treated with a CGRP receptor antagonist (CGRP_8-37), the CGRP-mediated inhibition of Ang II-induced ROS and apoptosis was completely abolished. Moreover, pre-treatment with N-acetyl-L cysteine (NAC), an ROS scavenger, blocked the effects of CGRP on Ang II-induced apoptosis. In addition, the activation of CaMKII and the downstream transcription factor CREB stimulated by Ang II was abrogated by CGRP. Importantly, in both CGRP and NAC-treated VSMCs, CGRP failed to further attenuate CaMKII and CREB activation. The results demonstrate that CGRP attenuated Ang II-induced ROS-dependent apoptosis in VSMCs by inhibiting the CaMKII/CREB signalling pathway.

[Clinical differences between primary nasopharyngeal NK/T-cell lymphoma and primary nasal cavity NK/T-cell lymphoma with nasopharynx extension]

Objective: To investigate the clinical and prognostic differences between primary nasopharyngeal natural killer (NK)/T-cell lymphoma (NP NKTCL) and extranodal NK/T-cell lymphoma of the nasal cavity with nasopharynx extension (N-NP NKTCL). Methods: A total of 89 patients with NP NKTCL and 113 patients with N-NP NKTCL from January 2000 to June 2015 were retrospectively analyzed. Clinical and pathological features, treatment responses and prognosis were compared between the two groups. Results: NP NKTCL patients showed similar clinicopathological features with those with N-NP NKTCL, except that the former had a relative low proportion of elevated lactate dehydrogenase (LDH) levels (28.1% vs. 41.6%; P=0.001). Both of two groups presented with high proportion of cervical lymph node involvement (55.1% and 42.5%; P=0.076). The 5-year overall survival (OS) rates in these two groups were 63.2% and 54.6%, respectively, whereas 5-year progress-free survival (PFS) rates were 50.7% and 45.6%, respectively. For the patients with stage Ⅰ and Ⅱ, the 5-year OS and PFS rates in these two groups were 68.8% and 55.7% as well as 55.6% and 47.2%, respectively. These were no statistically significant differences between two groups (all P>0.05). The complete response (CR) rate after initial chemotherapy in NP NKTCL group was 43.8%, which was significant higher than that of 19.6% in N-NP NKTCL group (P=0.006). Additionally, the CR rate after primary radiotherapy was 63.4% and 62.7%, respectively (P=0.629). The NP NKTCL patients with stage Ⅰ and Ⅱ who accepted radiotherapy with or without chemotherapy had similar survival times with chemotherapy alone, showing the 5-year OS rates of 70.5% and 33.3% (P=0.238), as well as the 5-year PFS rates of 56.7% and 33.3%, respectively (P=0.431). Similar results were found in N-NP NKTCL group, the 5-year OS rates for patients with radiotherapy with or without chemotherapy and chemotherapy alone were 57.4% and 33.3% (P=0.246), while the 5-year PFS rates were 49.3% and 16.7% (P=0.177), respectively. Besides, the relapse pattern of NP NKTCL and N-NP NKTCL groups was also similar, mainly involving the distant extra-nodal organs followed by lymph nodes. Conclusion: The patients with N-NP NKTCL and NP NKTCL showed similar clinical and prognostic features, however, the initial response to chemotherapy was different.

[Screening of the SETX gene in sporadic amyotrophic lateral sclerosis patients of Chinese origin]

Objective: To investigate all coding regions of amyotrophic lateral sclerosis (ALS)-related gene Senataxin (SETX) in sporadic amyotrophic lateral sclerosis patients of Chinese origin. Methods: From January 2010 to December 2014, the peripheral venous blood samples and clinical data were collected from 311 patients with sporadic amyotrophic lateral sclerosis (SALS) and 311 healthy controls who were of Chinese ancestry from the Department of Neurology, Chinese PLA General Hospital.Genomic DNA was extracted from peripheral venous blood of all participants using standard methods. The coding regions of SETX were amplified by polymerase chain reaction (PCR) and screened for mutations using next-generation sequencing technology. The online software SIFT and PolyPhen-2 were used to analyze the conservation of an altered amino acid and predict the potential pathogenicity of identified mutations. The SPSS 22.0 software was used to analyze the clinical feature of all participants. Results: Tenkinds of rare and one novel nonsynonymous mutations were identified and were absent in 311 controls. Twelve (3.86%) patients carried one SETX gene mutation. Five (1.61%) out of above-mentioned 12 patients carried highly pathogenic mutations including p. Pro1868Leu (c.5603G>A), p. Pro1331Leu (c.3992G>A), p. Glu756Val (c.2267T>A), p. Leu564Val (c.1690A>C), and p. Asn144Ser (c.431T>C). Patients carried SETX mutations were not different from other patients in onset age. Conclusion: Mutations in SETX are likely to be a pathogenesis for Chinese sporadic amyotrophic lateral sclerosis.

[Study on the characters of wideband tympanometry in newborns with normal hearing]

Objective:The aim of this study is to establish the characteristic of wideband tympanometry (WBT) in neonates with normal hearing. Method:Ninety newborn babies (149 ears) who had received rooming in care and passed hearing screening were randomly selected to test WBT. The screening programme consisted of distortion product otoacoustic emissions (DPOAE) and tympanometry at 1 kHz. The eigenvalue of ear canal volume, middle ear resonance frequency and acoustic absorptivity were obtained initially to explore the influence of gender and mode of delivery on the eigenvalues. Result:①Ear canal volume: The ear canal volume varied within (0.50±0.12)ml. The statistically significant correlationwas observed between ear canal volume and gender as well as the way of delivery (P<0.01). ②Resonance frequency: the resonant frequency distributed from 128 Hz to 642 Hz (mean 328.2±125.76 Hz). No statistically significant correlation (P>0.05) was observed between resonance frequency and gender as well as the way of delivery. ③Frequency wideband absorbance function: the shape of the curve showed two peaks and two troughs. The three most values were located in 1 296 Hz, 2 000 Hz and 5 339 Hz. No statistically significant correlation (P>0.05) was observed between acoustic absorptivity and gender as well as way of delivery. Conclusion:Resonance frequency and frequency acoustic absorptivity functions of newborns are different from adults. It is necessary to establish the normal reference value of WBT for newborns in China in order to promote this technique in the clinic.

Prevalence of pathogenicity island ETT2 in Escherichia coli isolated from piglets with diarrhea in northeast of China

Our aim was to investigate the prevalence of the pathogenicity island ETT2 and to examine the relationship between the ETT2 locus and other virulence factors in Escherichia coli (E. coli) isolated from piglets with diarrhea. A total of 354 E. coli strains isolated from scouring piglets were tested using PCR for the presence of the ETT2 locus. The E. coli strains were also analyzed for enterotoxins, fimbriae, non-fimbrial adhesin, Shiga toxins, pathogenicity islands, α-haemolysin (hlyA), afa8 gene cluster and autotransporter protease (sepA) genes. The results showed that 215 (60.7%) of the isolates possessed the ETT2 island. In 215 ETT2-positive E. coli strains, the virulence genes found were EAST1 (27.0%), irp2 (18.6%), paa (15.4%), STb (7.9%), LT (6.5%), ler (4.7%), hlyA (3.7%), AIDA-I (3.7%), K88 (3.7%), eae (3.3%), STa (2.8%), afaD (1.4%), afaE (1.4%), K99 (0.9%) and sepA (0.47%), respectively, and the isolates could be assigned into 25 different virulence factor patterns. In 139 ETT2-negative E. coli strains, the virulence genes detected were EAST1 (38.9%), paa (14.4%), STb (11.5%), AIDA-I (10.1%), irp2 (7.9%), sepA (2.16%), LT (0.7%), STa (0.7%), eae (0.7%), ler (0.7%), hlyA (0.7%) and K88 (0.7%), respectively, and the isolates could be classified into 13 different virulence factor patterns. Moreover, the occurrence of LT gene of ETT2-positive E. coli strains was far more than that of ETT2-negative E. coli strains.

Prostaglandin E2 restrains human Treg cell differentiation via E prostanoid receptor 2-protein kinase A signaling

Regulatory T cells (Treg cells) belong to a class of immunosuppressive cells that control the pathological changes of autoimmunity and inflammation. Prostaglandin E₂ (PGE₂) is a potent lipid mediator of immune inflammation including rheumatoid arthritis (RA) that exerts its effects via four subtypes of G-protein-coupled receptors (EP1-4). The ability of PGE₂ to regulate human Treg differentiation has not yet been reported. In the current study, we investigated the effects of PGE₂ on the differentiation of naïve T cells from healthy and RA patients into Treg cells and the intracellular signaling involved in this process in vitro. Our data indicate that PGE₂ negatively influenced the percentage of Treg cells and Foxp3 mRNA expression. The regulatory effects of PGE₂ were associated with increased intracellular cAMP levels and PKA activity. EP2 receptors may mediate the inhibitory role of PGE₂, since PGE₂ actions were mimicked by EP2 agonist (Butaprost) and cAMP agonist (Sp-8-CPT-cAMPS) but were reversed by an EP2 antagonist (PF-04418948) and a PKA inhibitor (H-89). PGE₂ negatively modulated the expression of cytotoxic T lymphocyte antigen-4 (CTLA-4) and glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR), as well as the production of interleukin (IL)-10 by Treg cells via EP2 receptors and cAMP/PKA signaling. All these findings indicate that PGE₂ can inhibit Treg differentiation mediated through the EP2-cAMP/PKA signaling pathway, and suggest novel immune-based therapies for use in RA treatment.

[Characteristics of repetitive nerve stimulation in 53 cases of amyotrophic lateral sclerosis]

Objective: To investigate the feature of repetitive nerve stimulation (RNS) in patients with amyotrophic lateral sclerosis (ALS) and correlation between RNS and clinical features and electromyography (EMG) findings of the corresponding muscle. Methods: Needle EMG and RNS were performed in 53 patients with ALS, who were recruited into Department of Neurology of Chinese PLA general hospital during April to December in 2016. Decrement of the compond muscle action potential (CMAP) in response to RNS of different nerves and stimulus frequencies was compared. The effects of gender, age of onset, disease duration, region of onset, ALS functional rating scale-revised (ALSFRS-R) and rate of disease progression (ΔFS) on the decrement were analyzed. Results: 49.1% of patients with ALS had decremental responses to low frequency RNS (LF-RNS) in accessory nerve, which was lower in ulnar nerve (4.3%) and common peroneal nerve (2.6%). Decremental responses of accessory nerve at 3 Hz were observed in 49.1% of patients with ALS, more frequent than 30.2% at 1 Hz. None of the patients had increased responses to high frequency RNS. Patients with upper-limb-onset, longer disease duration and lower ALSFRS-R tended to have more frequent decrement of CMAP in response to RNS. The decrement with LF-RNS of accessory nerve was in concert with neurogenic damage of sternocleidomastoid muscle with needle EMG (r=0.365, P=0.007). There were 3 patients who had decremental responses to LF-RNS in accessory nerve without clinical involvement and neurogenic damage of sternocleidomastoid muscle. Conclusions: There is significant decrement of CMAP in response to LF-RNS of accessory nerve in patients with ALS, which may reveal neuromuscular junction (NMJ) impairment. It may indicated a dying-back pattern of disease progression which derived from motor neuron terminal or NMJ to neuronal soma that some patients with ALS have decremental responses in RNS without clinical involvement and neurogenic damage of sternocleidomastoid muscle.

[Clinical outcome of intramyocardial dissecting hematoma after acute myocardial infarction]

Objective: To observe the clinical outcome of intramyocardial dissecting hematoma (IDH) after acute myocardial infarction (MI). Methods: The clinical characteristics and outcomes of nine patients with IDH after acute MI in Beijing Anzhen Hospital from 2010 to 2014 were retrospectively assessed, and all the patients were followed up. Results: The mean age of nine IDH patients (7 males, 2 females) was (61±5) years. One patient was diagnosed as right ventricular IDH and died before surgery because of deteriorated cardiac and renal failure. Eight patients were diagnosed as left ventricular IDH, among whom 1 patient died of perioperative bleeding. The other 7 patients survived, among whom 5 cases were treated medically and 2 cases accepted surgical treatment. After 2-6 years of follow-up, the survived patients had no other complications. Conclusion: IDH after acute MI was a rare clinical event with a high mortality, and improvement of recognition of this rare condition may reduce its mortality, especially the right ventricular IDH.

Emulating Anyonic Fractional Statistical Behavior in a Superconducting Quantum Circuit

Anyons are exotic quasiparticles obeying fractional statistics, whose behavior can be emulated in artificially designed spin systems. Here we present an experimental emulation of creating anyonic excitations in a superconducting circuit that consists of four qubits, achieved by dynamically generating the ground and excited states of the toric code model, i.e., four-qubit Greenberger-Horne-Zeilinger states. The anyonic braiding is implemented via single-qubit rotations: a phase shift of π related to braiding, the hallmark of Abelian 1/2 anyons, has been observed through a Ramsey-type interference measurement.

Association of the NAD(P)H oxidase p22 phox gene C242T polymorphism with type 2 diabetes mellitus, diabetic nephropathy, and carotid atherosclerosis with type 2 diabetes mellitus: A meta-analysis

Background

Several epidemiological studies have evaluated the association between the NAD(P)H oxidase p22 phox gene C242T polymorphism and the risk of type 2 diabetes mellitus (T2DM), diabetic nephropathy (DN), and carotid atherosclerosis with T2DM (CA), but the results are inconclusive. This meta-analysis was therefore designed to clarify these controversies.

Methods

Systematic searches were performed using electronic databases such as MEDLINE, PubMed, EMBASE, and China National Knowledge Infrastructure, as well as through manual searching of the references of identified articles. A total of 11 publications were eligible for this meta-analysis after running a search on the NAD(P)H oxidase p22 phox gene C242T polymorphism, including 7 with outcomes for T2DM, 7 with outcomes for DN, and 3 with outcomes for CA. The pooled odds ratio (OR) with a 95% confidence interval (CI) was calculated using a fixed effects model (FEM) or a random effects model (REM). Publication bias was tested by Begg's funnel plot analysis. Sensitivity analysis was also performed.

Results

The results showed a significant association between the NAD(P)H oxidase p22 phox gene C242T polymorphism and T2DM risk in the allelic model (REM: OR = 1.23, 95% CI = 1.06–1.43), additive model (FEM: OR = 1.61, 95% CI = 1.14–2.26), and recessive model (FEM: OR = 1.50, 95% CI = 1.10–2.05). A significant association was also observed for DN in the allelic model (REM: OR = 1.25, 95% CI = 1.06–1.47), additive model (FEM: OR = 1.61, 95% CI = 1.08–2.38), and dominant model (REM: OR = 1.26, 95% CI = 1.03–1.54). However, no association was observed for CA. Similar results were obtained in subgroup analysis based on ethnicity.

Conclusions

Results of this meta-analysis suggest that the NAD(P)H oxidase p22 phox gene 242T allele might be associated with an increased risk of T2DM and DN, but not CA.

•

There are significant association between P22 phox gene C242T polymorphism with T2DM DN risk but no significant association with CA.

Multimedia fate and source apportionment of polycyclic aromatic hydrocarbons in a coking industry city in Northern China

A steady state Level III fate model was established and applied to quantify source-receptor relationship in a coking industry city in Northern China. The local emission inventory of PAHs, as the model input, was acquired based on energy consumption and emission factors. The model estimations were validated by measured data and indicated remarkable variations in the paired isomeric ratios. When a rectification factor, based on the receptor-to-source ratio, was calculated by the fate model, the quantitatively verified molecular diagnostic ratios provided reasonable results of local PAH emission sources. Due to the local ban and measures on small scale coking activities implemented from the beginning of 2004, the model calculations indicated that the local emission amount of PAHs in 2009 decreased considerably compared to that in 2003.

Predictors of survival in Chinese patients with lupus nephritis

The current study was to determine the predictors of survival in 491 Chinese patients with lupus nephritis (LN). All patients were evaluated and consecutively followed up from 2003 to 2010. The female: male ratio was 9.5:1, with a median age of 31.1 ± 12 years. Forty-nine (10.0%) patients were lost to follow-up and 47 (10.3%) patients died. The overall cumulative probability of survival at 5, 10, 15 and 20 years by Kaplan-Meier analysis was 88%, 77%, 53% and 45%, respectively. The log-rank test showed that the probability of survival was significantly decreased in the late-onset patients (≥50 years) ( P = 0.036), patients with hypoproteinaemia (≤35 g/l) ( P = 0.014), patients with increased creatinine (≥1.5 mg/dl) ( P = 0.002) and patients with massive proteinuria (≥3.5 g/24 h) ( P = 0.009). However, the probability of survival was significantly higher in patients treated with hydroxychloroquine (HCQ) ( P = 0.003) than those not treated with it. Based on a multivariate model, increased creatinine (hazard ratio (HR) = 2.041; P = 0.017) and proteinuria ≥3.5 g/24hours (HR=1.716; P = 0.016) were independent risk factors. Glucocorticoid (HR = 0.457; P = 0.01) and HCQ (HR=0.197; P = 0.026) were independent protective factors. Our findings suggest that renal dysfunction and massive proteinuria are independent risk factors for mortality. HCQ could improve the survival of patients with LN.

Analysis of prognosis-related factors in patients with invasive cervical adenocarcinoma

OBJECTIVE

To explore the prognostic related factors in patients with cervical adenocarcinoma.

METHODS

Clinical and pathological data were retrospectively analyzed in 144 patients with cervical adenocarcinoma between 1995 and 2004.

RESULTS

Five-year survival rates were 80.1%, 59.7%, 6.3 % and 0.0%, respectively, in patients with Stage I, II, III and IV cervical adenocarcinoma, and the overall 5-year survival rate was 59.0%. Univariate analysis indicated poor prognosis in non-exophytic tumor, tumor diameter > 4 cm, advanced clinical stage, mucinous adenocarcinoma and clear cell carcinoma, or poorly differentiated tumor. The prognosis was related to lymph node metastasis and deep myometrial invasion. Multivariate analysis indicated that besides clinical stage, myometrial invasion and lymph node metastasis, tumor shape was also an independent prognostic related factor.

CONCLUSION

The prognosis is associated with tumor shape besides pre-confirmed clinical stage, myometrial invasion and lymph node metastasis. Ovarian preservation in young women remains to be further explored.

Preliminary evaluation on the use of homing pigeons as a biomonitor in urban areas

This study evaluates the usefulness of homing pigeons as a biomonitor of polycyclic aromatic hydrocarbons (PAHs) in urban environments. The mean concentrations of total PAHs in liver and lung tissues were greater in pigeons from Beijing compared to pigeons from Chengdu, however, this difference was only statistically significant for PAH concentrations in liver tissue (P < 0.05). Similarly, the severity of anthracosis or pneumoconiosis in lung tissue and hepatitis in liver tissue was greater in pigeons from Beijing compared to pigeons from Chengdu. Low molecular weight PAHs dominated the contribution of individual PAHs in both tissues. Significant differences (P < 0.05) were observed for most low and moderate molecular weights PAHs in liver and for some low and high molecular weights PAHs in lung between the two cites. The profile patterns of individual PAHs were similar between lung tissue of pigeons and between local ambient airs in summer for both cities, whereas the profile patterns between liver tissue and pigeon food were less similar. These data suggest that homing pigeons may be of value as a biomonitor of environmental pollution in urban areas.

Organochlorine pesticide residuals in chickens and eggs at a poultry farm in Beijing, China

Chicken organs, animal feed, droppings, and ambient air were sampled at a farm in Beijing to determine the concentrations of hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane and metabolites (DDTs). Mean fresh weight concentrations of HCHs and DDTs were 0.122+/-0.061 ng/g and 0.051+/-0.038 ng/g in the muscles. These values are 1-2 orders of magnitude lower than those reported in China in 1980. Contaminated feed was the main source of HCHs and DDTs. Only 12.8% of HCH and 3.3% of DDT of the amount consumed were excreted. Accumulated quantities of HCHs and DDTs increased during growth. However, concentrations of HCHs and DDTs did not increase because of dilution from rapid growth. Based on the observed residual levels in mature chicken and the average diet of residents of China, the contributions from chicken and egg consumption to per capita daily intake of HCHs and DDTs were 487% and 88% of those of fish consumption.

Spatial and temporal variations and possible sources of dichlorodiphenyltrichloroethane (DDT) and its metabolites in rivers in Tianjin, China

Water, suspended solid (SS) and sediment samples were collected from nine water courses in Tianjin, China and analyzed for dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDXs, including o,p'-,p,p'-DDT, DDD and DDE). The average DDX concentrations in water, SS and sediment were 59+/-30 ng l(-1), 2690+/-1940 ng g(-1)dry wt. and 340+/-930 ng g(-1)dry wt., respectively. Due to the termination of the extensive agricultural application and industrial manufacture, DDXs in river sediment decreased by one order of magnitude since 1970's and low DDT fractions in these sediments were observed. Still, DDXs in the sediments near the outlets of the major manufacturers remained relatively high attributed to the historic input. DDXs in sediment were also positively correlated with organic matter content. Spatial distributions of DDXs in SS and water was different from that in sediment. For SS, a negative correlation between DDX concentration and SS content indicated a dilution effect in many rivers. Dissolved organic carbon content was the major factor affecting DDX concentrations in water phase. Wastewater discharged from dicofol manufacturers and likely illegal agricultural application were the primary reasons causing high DDT (DDE+DDD) ratios in SS and water.

Partitioning and source diagnostics of polycyclic aromatic hydrocarbons in rivers in Tianjin, China

Water, suspended particulate matter (SPM), and sediment samples were collected from ten rivers in Tianjin and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), dissolved organic carbon (DOC), particulate organic carbon (POC) in SPM and total organic carbon (TOC) in sediment. The behavior and fate of PAHs influenced by these parameters were examined. Generally, organic carbon was the primary factor controlling the behavior of the 16 PAH species. Partitioning of PAHs between SPM and water phase was studied, and K(OC) for some PAH species were found to be significantly higher than the predicted values. The source of PAHs contamination was diagnosed by using PAH isomer ratios. Coal combustion was identified to be a long-term and prevailing contamination source for sediment, while sewage/wastewater source could reasonably explain a short-term PAHs contamination of SPM.

Short-term dynamic change of gill copper in common carp, Cyprinus carpio, evaluated by a sequential extraction

Dynamic changes in Cu speciation and its binding to fish gills were investigated by exposing common carp (Cyprinus carpio) to a 1 mg/1 Cu solution for 7 hours. Cu speciation in the bulk solution and fish gill microenvironment was calculated using general chemical equilibrium modeling. A sequential extraction procedure using distilled water, magnesium dichloride (1.0 mol/1), and acetic acid (10%) was used to characterize the Cu associated with the fish gills. Cu residual in the gill tissue was measured after the sequential extraction. Changes in total Cu concentration, pH, and dissolved organic carbon (Doc) in the bulk solution were recorded during the experimental period and calculated for the fish gill microenvironment. Cu-hydroxide species and Cu2 were dominant Cu species in both bulk solution and the fish gill microenvironment, whereas increased Cu-mucus was found in the fish gill microenvironment. DOC in the exposure medium, assumed to arise from mucus release, also increased and complexed Cu in solution. Forty-three percent of the Cu associated with the gills was readily water extractable, with an additional 22% exchangeable with Mg2+ or protons. Only 35% of the Cu accumulated within the gill tissues. The binding of Cu to the fish gills reached apparent equilibrium after 3 hours of exposure. Furthermore, the amount of water-extractable Cu within the gills showed significant correlation to the concentration of Cu predicted to be complexed with calculated free mucus in the gill microenvironment.

Distribution of sorbed phenanthrene and pyrene in different humic fractions of soils and importance of humin

Contributions of fulvic-humic acids (FA/HA) and humin (HM) to sorption of phenanthrene (PHE) and pyrene (PYR) in a soil were differentiated using a humic separation procedure after multi-concentration sorption experiments. It was found that the amount of solutes in FA/HA did not change significantly after 48 h, while that in HM increased continuously and slowly up to the end of the experimental period (720 h), indicating that HM was the main region for slow sorption. Based on the fitting results using Freundlich equation, it was found that nonlinearity of both solutes was greater in HM than in FA/HA, consistent with the sorption characteristics of individually extracted HA and HM in a separate experiment. The observed nonlinearity of the solute distribution was confirmed by using three other soil samples with organic carbon contents ranging from 0.7 to 7.9%. Distribution dynamics of PHE and PYR among various fractions were also discussed.

Geostatistical analysis and kriging of Hexachlorocyclohexane residues in topsoil from Tianjin, China

A previously published data set of HCH isomer concentrations in topsoil samples from Tianjin, China, was subjected to geospatial analysis. Semivariograms were calculated and modeled using geostatistical techniques. Parameters of semivariogram models were analyzed and compared for four HCH isomers. Two-dimensional ordinary block kriging was applied to HCH isomers data set for mapping purposes. Dot maps and gray-scaled raster maps of HCH concentrations were presented based on kriging results. The appropriateness of the kriging procedure for mapping purposes was evaluated based on the kriging errors and kriging variances. It was found that ordinary block kriging can be applied to interpolate HCH concentrations in Tianjin topsoil with acceptable accuracy for mapping purposes.

Accumulation and distribution of polycyclic aromatic hydrocarbons in rice (Oryza sativa)

Various tissues of rice plants were sampled from a PAH contaminated site in Tianjin, China at different growth stages of the ripening period and analyzed for PAHs. PAHs were much higher in roots than in the exposed tissues. Grains and internodes accumulated much smaller amounts of PAHs than leaves, hulls or ear axes. No specific gradient trends along roots, stem, ear axes, and grains were observed, suggesting that systematic translocation among them is unlikely. Over the ripening period, PAH concentrations were increased in rice roots and decreased in most above-ground tissues. Significant correlations between PAH and lipid contents can only be observed during full mature stage. The spectra of individual PAH compounds in rice organs including roots were similar to those in air, rather than those in soil. There was also a significant correlation between bioconcentration factor (BCF, plant over air) and octanol/air partitioning coefficient (Koa).

Particle size distributions of polycyclic aromatic hydrocarbons in rural and urban atmosphere of Tianjin, China

The size distributions of 16 polycyclic aromatic hydrocarbons (PAHs) and particle mass less than 10 microm in aerodynamic diameter (Dp) were measured using a nine-stage low-volume cascade impactor at rural and urban sites in Tianjin, China in the winter of 2003-2004. The particles exhibited the trimodal distribution with the major peaks occurring at 0.43-2.1 and 9.0-10.0 microm for both urban and rural sites. The concentrations of the total PAH (sum of 16 PAH compound) at rural site were generally less than those of urban site. Mean fraction of 76.5% and 63.9% of the total PAH were associated with particles of 0.43-2.1 microm at rural and urban sites, respectively. Precipitation, temperature, wind speed and direction were the important meteorological factors influencing the concentration of PAHs in rural and urban sites. The distributions of PAHs concentration with respect to particle size were similar for rural and urban samples. The PAHs concentrations at the height of 40 m were higher than both of 20 and 60 m at urban site, but the mass median diameter (MMD) of total PAH increased with the increasing height. The mid-high molecular weight (278 >or= MW >or= 202) PAHs were mainly associated with fine particles (Dp <or= 2.1 microm), whereas low molecular weight (128 >or=MW >or=178) PAHs were distributed in both of fine and coarse particle. The fraction of PAHs associated with coarse particles (Dp>2.1 microm) decreased with increasing molecular weight. The relatively consistent distribution of PAHs seemed to indicate the similar combustion source of PAHs at both of rural and urban sites. The fine differences of concentration and distribution of PAHs at different levels at urban site suggested that the different source and transportation path of particulate PAHs.

Modeling the dynamic changes in concentrations of gamma-hexachlorocyclohexane (gamma-HCH) in Tianjin region from 1953 to 2020

A level IV fugacity model was used to simulate the dynamic changes of gamma-hexachlorocyclohexane (gamma-HCH) concentrations in environmental media in Tianjin, China. A similar model (level III) was previously used and validated under steady state conditions; this paper explores its dynamic behavior. Application of the level IV fugacity model has been validated using independently observed gamma-HCH concentrations in various media during the early 1980s and during 2001. Sensitivity analysis was conducted using coefficient-of-variation normalized sensitivity coefficients. The model was also subject to uncertainty analysis using Monte Carlo simulation. It was found that concentrations of gamma-HCH reached within 95% of their steady-state levels in all media after less than 15 years. Around one order-of-magnitude decreases in gamma-HCH concentrations in various media occurred between 1993 and 2001. We project that gamma-HCH concentrations will decrease another 1.7-1.9 orders of magnitude to reach 1.1 (0.9-1.2) x 10(-14), 2.7 (2.5-3.0) x 10(-10), 1.2 (1.1-1.3) x 10(-7), and 6.1 (5.4-6.8) x 10(-8) mol/m(3), in air, water, soil, and sediment, respectively, by 2020. The sensitivities and true uncertainty of the model are discussed.

[Genetic analysis and mapping of the rice leafy-hull mutant Oslh]

Oslh (lh=leafy hull), in the japonica cultivar 9522 background, a mutant of Oryza sativa L. spp. japonica cv. 9522 identified from an M(2) population, was mutagenized by irradiation with (60)Co gamma-ray. The Oslh mutant plants flowered about 15 days later than the wild-type plants (Fig.1e). The paleas, lemmas and lodicules of the flowers of Oslh mutant were transformed into leaf-like structures (Fig.1b, d). Genetic analysis of the F(2) progeny from a cross between the Oslh mutant and wild-type japonica cv. 9522 revealed that the Oslh mutant arouse from a single recessive nuclear gene mutation of the cv. 9522. To map the Oslh locus, an F(2) population generated by crossing between Oslh (japonica) mutant and Guangluai4 (indica) was analyzed. The Oslh locus was mapped to the long arm of rice chromosome 3, between a SSR marker RM5475 and an InDel marker GY305, 2.9 and 1.5 cM away from these two markers respectively (Fig.4). These results are useful for further cloning and functional analysis of the OsLH gene.

Source diagnostics of polycyclic aromatic hydrocarbons based on species ratios: a multimedia approach

Often, the sources of polycyclic aromatic hydrocarbons (PAHs) in environmental media can be identified by comparing the ratios of concentrations of selected pairs of PAH congeners in the source emissions to the ratios in the contaminated environmental media. However, these ratios can be altered significantly due to differences in the transport of the PAH compounds in a multimedia environment. To examine such changes, a fugacity model was applied to PAH ratios in a model environment. A linear relationship between the rate of emission and the bulk media concentration was identified for each PAH compound in an environmental medium at steady state and was quantified by a receptor-to-source ratio (RRS). It was demonstrated that the RRS values of the two congeners usually differ significantly. Consequentially, PAH ratios changed remarkably from the source emissions to various environmental media. A site-specific rectification factor (RF) was defined as the ratio of the two RRS values of the paired congeners for a specific PAH ratio in a given medium, which can be applied to account for the ratio changes in a multimedia environment. The PAH ratio changes were further verified with the surface soil data collected from Tianjin, China, and the observed changes of PAH ratios were compared favorably with the model predictions. The sensitivity analysis revealed that PAH ratios of the low molecular weight compounds were less stable. The most influential parameters controlling PAH ratios were those pertaining to dry precipitation, surface-to-air diffusion, degradation in air and water, and exchange between water and sediment.

Human exposure and health risk of alpha-, beta-, gamma- and delta-hexachlorocyclohexane (HCHs) in Tianjin, China

The dynamic exposures to HCHs of individuals born between the years 1913 and 1993 in Tianjin have been simulated by connecting a fugacity model (IV) with a multimedia exposure model. Ingestion is the most important pathway for human beings to take up HCHs, and concentrations in the human body correlate with body weight changes. Accumulations of HCHs were derived assuming that the degradation in human body behaved linearly. The health risk of exposure to HCHs was measured using cancer risk and loss of life expectancy (LLE), and LLE was modified from its original definition to incorporate a dynamic calculation that takes variances in exposure into account. Monte-Carlo simulations were run to analyze the uncertainties of the model.

Organochlorine pesticides in agricultural soil and vegetables from Tianjin, China

Samples of eight types of vegetables, the rhizosphere soils, and bulk soils were collected from two sites (A and B) in Tianjin, China for the determination of hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane and metabolites (DDXs). The average concentrations of total HCHs and DDXs in the bulk soils were 3.6 and 80.1 ng/g for site A and 102 and 235 ng/g for site B, respectively. Relative accumulations of HCHs and DDXs in the rhizosphere soil from site A but not site B were demonstrated. The concentrations of total HCHs and DDXs in vegetable roots were 3.6-60 and 4.2-73 ng/g for site A and 15-152 and 7.1-136 ng/g for site B, respectively. Difference in bioaccumulation among various vegetables, especially between tuber and fibrous vegetables was significant. DDXs in spinach and cauliflower from site B and lindane (gamma-HCH) in cauliflower from both sites and violet from site B exceeded the maximum residual limits. Linear correlation of log-transformed HCHs and DDXs contents between the vegetable roots and the rhizosphere soils suggests the direct uptake of HCHs and DDXs.

Contamination of rivers in Tianjin, China by polycyclic aromatic hydrocarbons

Tianjin urban/industrial complex is highly polluted by some persistent organic pollutants. In this study, the levels of 16 priority polycyclic aromatic hydrocarbons (PAHs) were tested in sediment, water, and suspended particulate matter (SPM) samples in 10 rivers in Tianjin. The total concentration of 16 PAHs varied from 0.787 to 1943 microg/g dry weight in sediment, from 45.81 to 1272 ng/L in water, and from 0.938 to 64.2 microg/g dry weight in SPM. The levels of PAHs in these media are high in comparison with values reported from other river and marine systems. Variability of total concentrations of PAHs in sediment, water, and SPM from nine different rivers is consistent with each other. No obvious trends of total PAHs concentration variations were found between upstream and downstream sediment, water, and SPM samples for most rivers, which indicate local inputs and disturbances along these rivers. The spatial distributions of three-phase PAHs are very similar to each other, and they are also similar to those found in topsoil. However, their chemical profiles are significantly different from that of topsoil. The change of profiles is consistent with the different aqueous transport capability of 16 PAHs. Low molecular weight PAHs predomination suggests a relatively recent local source and coal combustion source of PAHs in the study area.

Evaluation of factors influencing root-induced changes of copper fractionation in rhizosphere of a calcareous soil

Major factors influencing the root-induced copper fractionation changes within the rhizosphere of maize, wheat, pea, and soybean seedlings were evaluated using a contaminated calcareous soil. The effects of acidification, alkalization, and introduction of root exudates were investigated by addition of acid, alkaline and root exudates from solution cultures, prior to incubation and copper fractionation. Raw and sterilized soils were compared for changes of copper fractionation in the rhizosphere using rhizoboxes with maize, wheat, pea and soybean seedlings. The results indicated that the general trend in considerable changes was similar among the plant species studied. The rhizosphere experienced a depletion of carbonate associated and organic bound copper along with an accumulation of exchangeable and Fe-Mn oxide bound copper. The resulting significant influence of root exudates on copper fractionation appears to have been produced through complexation rather than acidification or alkalization. The increase in exchangeable copper in rhizosphere was strengthened by microorganisms.

Residues of hexachlorocyclohexane isomers and their distribution characteristics in soils in the Tianjin area, China

Hexachlorocyclohexane (HCH) has a history of use in China. This paper presents the results of an investigation of HCH residue isomers and their distribution characteristics in soils near Tianjin, China. One hundred eighty-eight soil samples were collected from the Tianjin area. Four HCH isomers-alpha-HCH, beta-HCH, gamma-HCH, and delta-HCH-were detected using gas chromatography for all samples. Concentrations of the sum HCH ranged from 1.3 to 1095 ng g(-1), among which beta-HCH accounted for 52.5%. In addition, residues of HCH within Tianjin's urban areas were found to be higher. No significant differences were found between the residues of HCH in soils from waste irrigation areas and those in other areas. Total organic carbon content was determined to impact the residue levels of HCH in soils, while pH value and clay content were not related to concentrations of HCH. In general, all HCH isomers in soil samples had abnormally high residue levels, possibly the result of continuous use of HCH in this area.

Sample purification for analysis of organochlorine pesticides in sediment and fish muscle

The methods of sample purification for determinations of organochlorine pesticides (OCPs) in sediment and fish muscle were investigated in this study. A two-step procedure with preliminary cleanup and florisil column fraction was adopted. The working conditions of florisil column were firstly optimized. As to preliminary cleanup, liquid-liquid extraction by mixture of dimethyl formamide (DMF) and hexane and sulphonation by concentrated sulfuric acid were applied respectively and compared for the studied samples. The results indicated that liquid-liquid distribution could effectively separate lipids from fish muscle extracts, while failed in elimination of chlorophyll extracted from the relicts of hydrophytes in the sediment sample. In view of the sample appearance and clarity of gas chromatogram, sulphonation was more suitable to purify the sediment sample, however, the recoveries of the spiked standards were poor. The use of eluting solvent with stronger polarity could improve the corresponding recoveries significantly. Due to complete loss of Dieldrin, Endrin, and Endrin aldehyde after sulphonation, this pretreatment was improper to the three components. Sulfur, as the particular disturbing element in sediment, could be removed sufficiently by addition of activated copper powder. The relevant detection limits of the selected methods for OCPs in the studied substrates were also provided.

Polycyclic aromatic hydrocarbons (PAHs) in agricultural soil and vegetables from Tianjin

Several types of vegetables were collected from two contaminated sites in Tianjin, China. The bulk soil and the rhizosphere soil samples were also collected from the same plots. Sixteen PAHs in the samples were measured. The total concentrations of PAH16 in the bulk soil from the two sites were 1.08 and 6.25 microg/g, respectively, with similar pattern. The concentrations of PAH16 and individual compounds in the rhizosphere were significantly higher than those in the bulk soil with mean values of 2.25 and 7.82 microg/g for the two sites, respectively. The contents of both total and dissolved organic matter in the rhizosphere were also higher than those in the bulk soil. Almost all PAH compounds studied were detected in both roots and aerial parts of the vegetables studied. Abundance of higher molecular weight PAHs in vegetable, however, was lower than that in soil. Concentrations of PAH16 in vegetable were higher than those reported in the literature for other areas. It appears that agricultural soils and vegetables in Tianjin, especially those from the site located immediately next to an urban district and irrigated with wastewater for several decades, are severely contaminated by PAHs. Among the eight types of vegetable studied, the highest concentration of PAHs was found in cauliflower. By average, the concentration of PAH16 in the aerial part of vegetables was 6.5 times higher as that in vegetable root, suggesting that foliar uptake is the primary transfer pathway of PAHs from environment to vegetables.

Use of sequential ASE extraction to evaluate the bioavailability of DDT and its metabolites to wheat roots in soils with various organic carbon contents

An accelerated solvent extraction (ASE) procedure using water, n-hexane and a mixture of n-hexane and acetone as solvents in sequence was developed and tested to evaluate the bioavailability of DDT and its metabolites including p,p'-DDT, o,p'-DDT, p,p'-DDE, and p,p'-DDD (SigmaDDTs) to wheat uptake from soils characterized by varied organic carbon contents. Results indicated that the extractability of SigmaDDTs with water was enhanced considerably in the presence of water soluble organic carbon (WSOC), while the amount of SigmaDDTs extracted with n-hexane was negatively correlated to the content of water insoluble organic carbon (WIOC). The interaction between SigmaDDTs and WIOC also reduced the bioavailability of the pesticides to wheat roots during uptake. There was a good positive correlation between the amount of SigmaDDTs extracted by n-hexane and the amount of SigmaDDTs accumulated in wheat roots, suggesting some potential for the use of the n-hexane ASE-extracted fraction as an indicator of SigmaDDTs' bioavailability to plant uptake. As such, the three sequentially extracted fractions may be viewed as representing the mobile, bioavailable, and fixed pools of SigmaDDTs in the soil.

Level and distribution of DDT in surface soils from Tianjin, China

One hundred and eighty eight surface soil samples were collected from the Tianjin area to study the contamination of DDT and its metabolites. Measurements were taken for p,p'-DDE, p,p'-DDD, p,p'-DDT, o,p'-DDE, o,p'-DDD and o,p'-DDT for all samples. The results indicated that p,p'-DDT and p,p'-DDE were the predominant contaminant compounds in the surface soil samples, with mean concentrations of 27.5 and 18.8 ng g(-1) respectively. No significant differences in DDT concentrations were found between the soils from wastewater treated irrigated areas and other areas, suggesting that wastewater irrigation is not an important source of DDT in the area. However, the spatial distribution of soil DDTs levels in the area did correlate well with early direct application rates of pesticides. In addition, both pH level and organic carbon content are also known factors affecting the level of DDT and its metabolites. Although it was assumed that the use of these chemicals was banned in the early 1980s, the current concentration levels appear to be too high to be mere residuals after 20 years degradation.