Ambient air pollution and adverse birth outcomes: a systematic review and meta-analysis

Several reviews have assessed the relationship between exposure to ambient air pollution and adverse birth outcomes during pregnancy, but the results remain controversial. The objective of this study was to assess this correlation quantitatively and to explore sources of heterogeneity. We included all published case-control or cohort studies that evaluated the correlation between ambient air pollution and low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA). Analytical methods and inclusion criteria were provided on the PROSPERO website (CRD42018085816). We evaluated pooled effects and heterogeneity. Subgroup analyses (grouped by exposure period, study settings, study design, exposure types, data source, Newcastle-Ottawa quality score (NOS), and adjustment for smoking or meteorological factors) were also conducted and publication bias was examined. The risk of bias in systematic reviews (ROBIS) tool was used to evaluate the overall risk of bias in this review. Forty studies met the inclusion criteria. We observed pooled odds ratios (ORs) of 1.03-1.21 for LBW and 0.97-1.06 for PTB when mothers were exposed to CO, NO₂, NO_x, O₃, PM_2.5, PM₁₀, or SO₂ throughout their pregnancy. For SGA, the pooled estimate was 1.02 in relation to NO₂ concentrations. Subgroup analysis and sensitivity analysis decreased the heterogeneity to some extent, such as the subgroups of continuous measures (OR=0.98 (0.97-0.99), I²=0.0%) and NOS>7 (OR=0.98 (0.97-0.99), I²=0.0%) in evaluating the association between PTB and NO₂. This review was completed with a low risk of bias. High concentrations of air pollution were significantly related to the higher risk of adverse birth outcomes. However, the sources of heterogeneity among studies should be further explored.

[Analysis of the relationship between ultrasonographic features and cervical lymph node skip metastasis of papillary thyroid micro-carcinoma]

Objective: To investigate the correlation between cervical lymph node skip metastasis with ultrasonographic characteristics of papillary thyroid micro- carcinoma (PTMC). Methods: We reviewed ultrasonographic features of 385 primary PTMC and cervical lymph node metastasis, confirmed by pathology in Tianjin Medical University Cancer Institute and Hospital, to evaluate the efficacy of ultrasonography in the diagnosis of cervical lymph node metastasis of PTMC patients. The relationship between ultrasonographic features of primary lesions and skip metastasis of cervical lymph nodes was analyzed by χ(2) test and multiple factor Cox regression. Results: Among the 385 cases of PTMC patients with cervical lymph node metastasis, 231 cases were central lymph node metastasis alone, 31 cases were lateral cervical lymph node metastasis alone, 123 cases were both central and lateral cervical lymph node metastasis. Among the 354 cases without skip metastasis of cervical lymph nodes, 48 cases were level Ⅱ, 92 cases were level Ⅲ, 83 cases were level Ⅳ, 9 cases were level Ⅴ, 354 cases were level Ⅵ. Among the 31 cases with skipping metastasis of cervical lymph nodes, 12 cases were level Ⅱ, 14 cases were level Ⅲ, 14 cases were level Ⅳ, 1 case was level Ⅴ. The sensitivity and specificity of preoperative ultrasonography in the diagnosis of central cervical lymph node metastasis were 46.3% and 66.7%, respectively, and those of lateral cervical lymph node were 91.0% and 87.8%, respectively. Univariate analysis showed that the abutment/perimeter, diameter and location of PTMC were significantly associated with skip metastasis (P<0.05), multivariate analysis showed that abutment/perimeter and location of PTMC were significantly associated with skip metastasis (P<0.05). Conclusions: The sensitivity and specificity of preoperative ultrasound diagnosis for lateral cervical lymph node metastasis of PTMC is higher than that of central metastasis. PTMC with abutment/perimeter ≥1/4 and upper portion location are prone to skip metastasis.

Postnatal nectin-3 knockdown induces structural abnormalities of hippocampal principal neurons and memory deficits in adult mice

The early postnatal stage is a critical period of hippocampal neurodevelopment and also a period of high vulnerability to adverse life experiences. Recent evidence suggests that nectin-3, a cell adhesion molecule, mediates memory dysfunction and dendritic alterations in the adult hippocampus induced by postnatal stress. But it is unknown whether postnatal nectin-3 reduction alone is sufficient to alter hippocampal structure and function in adulthood. Here, we down regulated hippocampal expression of nectin-3 and its heterophilic adhesion partner nectin-1, respectively, from early postnatal stage by injecting adeno-associated virus (AAV) into the cerebral lateral ventricles of neonatal mice (postnatal day 2). We found that suppression of nectin-3, but not nectin-1, expression from the early postnatal stage impaired hippocampus-dependent novel object recognition and spatial object recognition in adult mice. Moreover, AAV-mediated nectin-3 knockdown significantly reduced dendritic complexity and spine density of pyramidal neurons throughout the hippocampus, whereas nectin-1 knockdown only induced the loss of stubby spines in CA3. Our data provide direct evidence that nectins, especially nectin-3, are necessary for postnatal hippocampal development of memory functions and structural integrity.

[Chemical Compositions, Mass Concentrations, and Emission Factors of Particulate Organic Matters Emitted from Catering]

Catering is an important emission source of atmospheric particulate organic matters (POMs). Mass concentrations, chemical compositions, and emission factors of POMs emitted from catering were studied based on simulation experiments. The effects of different cooking methods, various ingredients, oils, and other factors were investigated. The results showed that the species of POMs emitted from catering were largely influenced by cooking methods, ingredients, and oils. Among all the quantified POMs, the average mass fraction was 68.9%, 20.3%, and 4.2% for N-alkanes, sterols, and fatty acids (including saturated fatty acids and unsaturated fatty acids), respectively. The remaining 5.42% was constituted by dicarboxylic acids, polycyclic aromatic hydrocarbons, monosaccharide anhydrides, and hopane compounds. The average ingredient emission factor was 0.0131 g·kg^-1, ranging from 0.0014 g·kg^-1 to 0.0271 g·kg^-1. The ingredient emission factors of the meat cooking process were much larger than those of the vegetable cooking process. The average oil emission factor was 1.8230 g·kg^-1, ranging from 0.0019 g·kg^-1 to 10.1730 g·kg^-1. The oil emission factors of barbecuing were much larger than those of other cooking methods.

Research on Computer-Aided Diagnosis of Alzheimer’s Disease Based on Heterogeneous Medical Data Fusion

Alzheimer’s disease is the third most expensive disease, only after cancer and cardiopathy. It is also the fourth leading cause of death in the elderly after cardiopathy, cancer, and cerebral palsy. The disease lacks specific diagnostic criteria. At present, there is still no definitive and effective means for preclinical diagnosis and treatment. It is the only disease that cannot be prevented and cured among the world’s top ten fatal diseases. It has now been proposed as a global issue. Computer-aided diagnosis of Alzheimer’s disease (AD) is mostly based on images at this stage. This project uses multi-modality imaging MRI/PET combining with clinical scales and uses deep learning-based computer-aided diagnosis to treat AD, improves the comprehensiveness and accuracy of diagnosis. The project uses Bayesian model and convolutional neural network to train experimental data. The experiment uses the improved existing network model, LeNet-5, to design and build a 10-layer convolutional neural network. The network uses a back-propagation algorithm based on a gradient descent strategy to achieve good diagnostic results. Through the calculation of sensitivity, specificity and accuracy, the test results were evaluated, good test results were obtained.

[Characterization of Volatile Organic Compounds from Cooking Emissions]

Volatile organic compounds (VOCs) do great harm to human health, and also have some impact on air quality. Cooking is one of the important sources of VOCs, so the study of cooking emissions is of great significance. By simulating the heating of oil and cooking, the characteristics and chemical composition of VOCs emissions for different types of oil fumes were analyzed by gas chromatography-mass spectrometry (GC-MS), using different oils, seasonings, and dishes as variables. The results show that the emission factors of the oils range from 0.81 to 2.53 g·kg^-1, and the emissions are dominated by halogenated hydrocarbons and alkanes. The emission factors of the seasonings range from 25.06 to 40.18 g·kg^-1, and the seasonings mainly emit alkanes. The quantity of emissions from chili fried meat is much higher than that of tomato scrambled eggs, and the chili fried meat mainly emits halogenated hydrocarbons, while tomato scrambled eggs mainly emit aromatic hydrocarbons and alkanes.

[Clinical analysis of cerebral venous sinus thrombosis in six children]

Objective: To summarize the clinical features of cerebral venous sinus thrombosis (CVST) in 6 children, and to improve the understanding of CVST in children. Methods: The risk factors, clinical presentations, laboratory findings, imaging manifestations, treatments and outcomes of 6 children (3 males, 3 females) with CVST admitted to the Department of Pediatrics, First Affiliated Hospital of Zhengzhou University from January 2012 to December 2017 were analyzed retrospectively. Results: The risk factors of disease were found in 5 cases, including 3 cases of infection, 1 case of L-asparaginase and dexamethasone chemotherapy and 1 case of oral prednisone alone. No definite risk factor was found in 1 case. The clinical presentations were headache in all cases, vomiting in 3 cases, convulsion in 2 cases, hemiplegia, photophobia, phonophobia and limitation of eyeball abduction in 1 case respectively. Magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) showed 2 cases of intracranial hemorrhage, 2 cases of cerebral parenchymal infarction and 2 cases of abnormal signal in venous sinus. Thrombus located in superior sagittal sinus in 4 cases, transverse sinus in 4 cases, sigmoid sinus in 3 cases and straight sinus in 1 case. After anticoagulation treatment, headache and vomiting were alleviated, and veins were recanalized in 6 cases. Two cases were diagnosed with eyeball abduction limitation and hemiplegia but did not improve in the short term after treatment. Conclusions: Infection is the main risk factor of CVST in children and headache is often the cause of medical consultation. Brain MRI and MRV are helpful in diagnosis and timely treatment can improve prognosis.

[The role and mechanism of mesenchymal stem cell in modulating human pulmonary microvascule endothelial cell permeability via paracrine hepatocyte growth factor]

Objective: To explore the role and mechanism of mesenchymal stem cell (MSC) in modulating human pulmonary microvascular endothelial cell (HPMECs) permeability via hepatocyte growth factor (HGF). Methods: The study introduced a co-cultured model between HPMECs and human mesenchymal stem cell conditioned media (MSC-CM) collected from MSCs after 24 h hypoxia culture, and meanwhile HGF was neutralized in MSC-CM by anti-HGF antibody respectively, followed by lipopolysaccharide (LPS) stimulation. Finally, the following measurements were performed: the permeability of HPMECs, the protein expression of vascular endothelial cadherin (VE-cadherin), Occludin in HPMECs by Western blot, HPMECs apoptosis by Annexin V-FITC/PI and HPMECs proliferation by 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di- phenytetrazoliumromide(MTT). Results: Compared to LPS group (4.15±0.88), MSC-CM reduced endothelial paracellular permeability injured by LPS(1.56±0.36, P<0.01), however, the MSC-CM effect was significantly blocked by anti-HGF antibody(3.11±0.74, P<0.05). Furthermore MSC-CM significantly increased the expression of VE-cadherin(0.71±0.05 vs. 0.38±0.19, P<0.05)and Occludin protein(0.96±0.05 vs. 0.51±0.02, P<0.05) in HPMECs, which was significantly blocked by anti-HGF antibody (P<0.05). MSC-CM significantly reduced the number of early apoptotic cells (6.82±1.80 vs. 17.09±1.89, P<0.05). However, the effect of MSC-CM was significantly blocked by neutralizing HGF (12.07±0.98, P<0.01). The cell viability results by MTT assay confirmed that MSC-CM(6.82±1.80, P<0.05)restored cell viability to a greater extent than LPS stimulation only(0.47±0.09), and meanwhile the MSC-CM effect was significantly inhibited by neutralizing HGF from MSC-CM with anti-HGF antibody (0.69±0.29, P<0.05). Conclusion: HGF secreted by MSCs reduces endothelial cell paracelluar permeability induced by LPS, and the possible mechanisms include remodelling of endothelial intercellular adherence junction, promoting endothelial cell proliferation and restraining endothelial cell apoptosis.

[Effects of human erythropoietin on transforming growth factor β1/Smad3 signal transduction pathway in acute wounds of rats]

Objective: To explore the effects of human erythropoietin (hEPO) on healing related transforming growth factor β₁ (TGF-β₁)/Smad3 signal transduction pathway in acute wounds of rats. Methods: Seventy-two healthy Sprague Dawley rats were divided into normal saline control group, low dose group, middle dose group, and high dose group according to the random number table, with 18 rats in each group, after round acute wounds with diameter of 2.5 cm were inflicted on the back of rats. Rats in the 4 groups had debridement routinely. Wounds of rats in normal saline control group were covered by gauzes infiltrated with 1 mL normal saline, while wounds of rats in low dose group, middle dose group, and high dose group were respectively covered by gauze infiltrated with 1 mL hEPO in doses of 50, 100, and 150 U every day, and then the wounds were bandaged with 6 layers of dry gauze. Dressing change was performed once every day. On treatment day (TD) 3, 7, and 14, 6 rats from each group were taken for general observation and calculation of wound healing rate. Then the wound tissue samples were harvested after the rats were sacrificed for observation of expressions of CD31 and transforming growth factor β₁ (TGF-β₁) with immunohistochemical method. Protein expression of phosphorylated Smad3 of the wound tissue of 3 rats were detected by Western blotting. Data were processed with analysis of variance of factorial design, one-way analysis of variance, least-significant difference test, and Bonferroni correction. Results: (1) On TD 3, obvious exudation and scab were observed in the wounds of rats in the 4 groups. On TD 7, the wounds of rats in low dose group, middle dose group, and high dose group were reduced compared with those in normal saline control group. On TD 14, all wounds of rats in the 4 groups were healed. On TD 7, the wound healing rates of rats in middle dose group and high dose group were significantly higher than the rate in normal saline control group (P<0.01). At the other time points, the wound healing rates of rats in the 4 groups were close (P>0.05). (2) CD31 mainly expressed in blood vessels. Except for those in low dose group on TD 3 and 7 (P>0.05), the expressions of CD31 in wound tissue of rats in low dose group on TD 14 and in middle dose group and high dose group on TD 3, 7, and 14 were significantly higher than those in normal saline control group (P<0.01). Except for those on TD 3 (P>0.05), the expressions of CD31 in wound tissue of rats in middle dose group and high dose group on TD 7 and 14 were significantly higher than those in low dose group (P<0.01). Except for that on TD 3 (P>0.05), the expressions of CD31 in wound tissue of rats in high dose group on TD 7 and 14 were significantly higher than those in middle dose group (P<0.01). (3) Except for that in low dose group on TD 3 (1.9±0.7, P>0.05), the expressions of TGF-β₁ in wound tissue of rats in low dose group on TD 7 and 14 (3.3±1.0, 3.7±0.7), and in middle dose group and high dose group on TD 3, 7, and 14 (3.3±1.0, 3.6±1.0, 3.9±0.9, 3.4±0.7, 3.8±0.8, 4.2±0.4) were significantly higher than those in normal saline control group (1.7±0.5, 2.7±1.0, 3.0±0.9, P<0.01). Except for those on TD 7 (P>0.05), the expressions of TGF-β₁ in wound tissue of rats in middle dose group and high dose group on TD 3 and 14 were significantly higher than those in low dose group (P<0.01). Except for that on TD 14 (P<0.01), the expressions of TGF-β₁ in wound tissue of rats in high dose group on TD 3 and 7 were close to those in middle dose group (P>0.05). (4) Except for those in low dose group on TD 3 and 14 and in middle dose group and high dose group on TD 14 (P>0.05), the protein expressions of phosphorylated Smad3 in wound tissue of rats in the 3 groups at the other time points were significantly higher than those in normal saline control group (P<0.01). Except for those on TD 14 (P>0.05), the protein expressions of phosphorylated Smad3 in wound tissue of rats in middle dose group and high dose group on TD 3 and 7 were significantly higher than those in low dose group (P<0.01). Except for that on TD 14 (P>0.05), the protein expressions of phosphorylated Smad3 in wound tissue of rats in high dose group on TD 3 and 7 were significantly lower than those in middle dose group (P<0.01). Conclusions: Exogenous hEPO can increase the expressions of CD31, TGF-β₁, and phosphorylated Smad3 in acute wounds of rats, promote angiogenesis of wounds, and activate TGF-β₁/Smad3 signal transduction pathway to promote wound healing.

Association between 5,10-methylenetetrahydrofolate, gene polymorphism and congenital heart disease

This article is to investigate the association between C677T polymorphism of 5, 10-methylenetetrahydrofolate (MTHFR) gene and congenital heart defects (CHD). Two hundred thirty-five nuclear families (father, mother and child) with CHD were enrolled in the study (experimental group), and two hundred thirty-five healthy nuclear families were selected as a control group. Under the case-control study, the C677T polymorphism of MTHFR gene was detected with polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. The distribution of genotype frequency in the CHD group and control group were analyzed. SPSS 13.0 software was used to analyze the data. The distribution of genotype frequency at C677T polymorphism site was significantly different between the CHD group (including ventricular septal defect, atrial septal defect, tetralogy of fallot, double outlet right ventricle, patent ductus arteriosus) (child and mother) and healthy control group (child and mother). There were no differences between CHD group-fathers and healthy control group-fathers. Analyses of the MTHFR genotypes of CHD nuclear family data with transmitted disequilibrium test (TDT) and haplotype-based haplotype relative risk statistical method both revealed significant indications that the parents transmitted more T allele of MTHFR to their CHD children. TT genotype of MTHFR gene is associated with CHD, and a mother or a child with T allele has a much higher risk of CHD.

CircularRNA_104670 plays a critical role in intervertebral disc degeneration by functioning as a ceRNA

This study was carried out to explore the roles of circular RNAs (circRNAs) in nucleus pulposus (NP) tissues in intervertebral disc degeneration (IDD). Differentially expressed circRNAs in IDD and normal NP tissues were identified based on the results of microarray analysis. Bioinformatics techniques were employed to predict the direct interactions of selected circRNAs, microRNAs (miR), and mRNAs. CircRNA_104670 was selected as the target circRNA due to its large multiplier expression in IDD tissues. After luciferase reporter and EGFP/RFP reporter assays, we confirmed that circRNA_104670 directly bound to miR-17-3p, while MMP-2 was the direct target of miR-17-3p. The receiver-operating characteristic (ROC) curve showed that circRNA_104670 and miR-17-3p had good diagnostic significance for IDD (AUC _{circRNA_104670} = 0.96; AUC _miRNA-17-3p = 0.91). A significant correlation was detected between the Pfirrmann grade and expression of circRNA_104670 (r = 0.63; p = 0.00) and miR-17-3p (r = −0.62; p = 0.00). Flow-cytometric analysis and the MTT assay showed that interfering with circRNA_104670 using small interfering RNA (siRNA) inhibited NP cell apoptosis (p < 0.01), and this inhibition was reduced by interfering with miR-17-3p. Interfering with circRNA_104670 suppressed MMP-2 expression and increased extracellular matrix (ECM) formation, which were also reduced by interfering with miR-17-3p. Finally, an MRI evaluation showed that circRNA_104670 inhibition mice had a lower IDD grade compared with control mice (p < 0.01), whereas circRNA_104670 and miRNA-17-3p inhibition mice had a higher IDD grade compared with circRNA_104670 inhibition mice (p < 0.05). CircRNA_104670 is highly expressed in the NP tissues of IDD and acts as a ceRNA during NP degradation.

‘RNA sponges’ may provoke lower back pain by soaking up regulatory RNAs that normally protect the protein infrastructure surrounding cells in intervertebral discs. Many people suffer from lower back pain arising from disc degeneration (IDD). A team led by Fei-Zou and Jian-Yuan Jiang at Fudan University, Shanghai, China set out to identify molecular mechanisms that might contribute to IDD. They focused on circular RNAs, non-protein coding RNAs that have been linked to a variety of diseases. The researchers learned that IDD is associated with strongly elevated expression of a circular RNA that acts as an ‘RNA sponge’, binding to and thereby inactivating other RNA molecules. This inactivation ultimately results in the excessive production of an enzyme that can damage the protein matrix that supports cells within spinal discs, potentially setting up the conditions for IDD.

[A propensity score-matched study on relationship between maternal respiratory infection in early pregnancy and gestational age]

Objective: To explore the association between maternal respiratory infection in early pregnancy and gestational age of single live birth. Methods: A face to face questionnaire survey was conducted among child bearing aged women in 30 counties (district) of Shaanxi province selected through stratified multistage sampling. Propensity score (PS) matched (1∶1) analysis was used to match participants with respiratory infections to those without respiratory infections. A multilevel linear model was used to investigate the association between respiratory infections and gestational age. Through the control of the confounders step by step, three models were established in this study: model 1 for the variable of respiratory infections before PS matching, model 2 was adjusted for variables in model 1 plus some other individual differences of mother and baby, and model 3 for the variable of respiratory infections after PS matching. Results: Of 28 848 child bearing aged women surveyed, 3 676 (12.74%) had respiratory infections in early pregnancy. After PS matching, 2 762 pairs were matched. Analysis with model 1 indicated that a decrease of 0.111 week (P<0.001) in gestational age was associated with a respiratory infection during the first trimester. Analysis with model 2 and model 3 indicated that a decrease of 0.058 week (P=0.025) and a decrease of 0.076 week (P=0.036) were associated with respiratory infection during the first trimester, respectively. Conclusion: The respiratory infection during the first trimester was associated with the decrease of the gestational age of newborn.

[Treatment Status and Emission Characteristics of Volatile Organic Compounds from Typical Industrial Sources]

The status of treatment equipment, the emission characteristics, and the ozone formation potential (OFP) of volatile organic compounds (VOCs) for 11 typical enterprises, which were categorized into the 8 major VOC emission industries identified by the emission inventory of a typical city in the Yangtze River Delta, are discussed in this paper. There was a large difference in the removal efficiency of non-methane hydrocarbon (NMHC) between different treatment techniques, and even an increase in concentration occurred after some of the treatments. The current treatment equipment for VOCs needs further optimization. The emissions of NMHC, benzene, toluene, and xylene in most of the surveyed enterprises exceeded their corresponding standards, with toluene the worst offender. The most abundant compounds in the eight emission industries were aromatic hydrocarbons and oxygenated VOCs, whereas aromatic hydrocarbons contributed the most to ozone formation potential. There were large differences in emission characteristics of VOCs from different industries. Priority should be placed on the industries that have large OFP when control strategies of VOCs are considered.

Significance and prognosis of epithelial-cadherin expression in invasive breast carcinoma

The objective of the present study was to investigate and analyze the epithelial-cadherin (E-cadherin) expression in invasive ductal carcinoma of the breast, and to analyze the associations between the expression and clinicopathological characteristics of lymph node metastasis and the prognosis of breast cancer. The immunohistochemical streptavidin-peroxidase method was used to detect the E-cadherin expression in 30 cases of breast fibroadenoma and in 450 cases of invasive breast cancer, and then the χ²test and Kaplan-Meier method were used to analyze the data. The 30 cases of breast fibroadenoma showed positive expression of E-cadherin. Specifically, results found that E-cadherin was highly expressed in 49.04% (77/157) of patients with non-metastatic breast cancer, while low expression was found in 50.96% (80/157). Additionally, E-cadherin was highly expressed in 29.69% (87/293) of patients with lymph node metastasis of breast cancer, with low expression in 70.31% (206/293); these differences were significantly different (χ²=16.53; P<0.001). E-cadherin was expressed in 35.48% (22/62), 33.73% (84/249), 63.83% (30/47) and 30.43% (28/92) of patients with luminal A type, luminal B type, human epidermal growth factor receptor-2positive and triple-negative breast cancer (TNBC), respectively. It was found that patients with high expression of E-cadherin had a better prognosis than the low expression group with regards to TNBC, and this result was significantly different (χ²=4.48; P=0.034). In conclusion, low E-cadherin expression was associated with lymph node metastasis in invasive breast cancer, and the patients with low expression also had a poor prognosis compared with those in the high expression group. The present results suggested that E-cadherin could be used in a prognostic index for patients with lymph node metastasis and TNBC.

Cortical Activation Changes in Hirayama Disease After Anterior Cervical Decompression and Fusion

BACKGROUND

Spinal cord injury may cause cortical reconstruction. We, therefore explored the changes in cortical activation before and after anterior cervical decompression and fusion surgery in patients with Hirayama disease (HD).

METHODS

In total, 17 cases with HD underwent anterior cervical decompression and fusion surgery. Blood oxygenation level-dependent functional magnetic resonance imaging scan was performed preoperatively, 3 months, 6 months, and 1 year after surgery. Activated voxels were compared between both hands after adjusting for head motion, slice timing, spatial normalization, and image smoothing. Grip strength also was tested in both hands.

RESULTS

A retrospective review indicated that the grip strength of the asymptomatic hand was significantly stronger than the symptomatic hand at the time point before the surgery, 3 months after surgery, 6 months after surgery, and 1 year after surgery (P < 0.001). The grip strength of both symptomatic and asymptomatic hands continuously increased within 6 months after surgery (P < 0.05), but it stopped at 1 year after the surgery. The symptomatic limb tends to produce bilateral activation in the primary motor area (M1) during motor tasks. Both contralateral and ipsilateral M1 activation were stronger in symptomatic hand tasks preoperatively (P < 0.05). Both contralateral and ipsilateral activation in M1 during symptomatic hand tasks began to reduce after surgery, and statistical significance was observed 6 months after surgery (P < 0.05). Contralateral activation was relatively even over 6 months of the surgery (P > 0.05).

CONCLUSIONS

After surgery, pathologic reconstruction may have occurred in the primary motor cortex. Recovery of motor function in the symptomatic limb was accompanied by decreased ipsilateral and contralateral M1 activation, as well as symptom improvement. These findings suggested that postoperative cortical activation changes may reflect functional recovery in HD.

[Estimation of Fine Particle (PM2.5) Emission Inventory from Cooking: Case Study for Shanghai]

Cooking is one of important emission sources of fine particles (PM_2.5). This study using the catering enterprises of Shanghai as an example, presents a method to estimate the PM_2.5 emission inventory from cooking according to the number of stoves, cooking time, and number of customers. Based on in situ measurements, the concentrations of PM_2.5 emissions ranged from 0.1 mg ·m^-3 to 1.8 mg ·m^-3, which exceeded the limit (1.0 mg ·m^-3 for lampblack) in the national standard. Organic carbon dominated the PM_2.5 emitted from cooking, accounting for more than 50%. Extremely high ratios of organic carbon to elemental carbon were observed, ranging from 58.8 to 752.3, which could be used as an indicator of cooking emissions. The emission factors of PM_2.5 in the catering industry are closely related to the scale of the catering enterprises. The emission factors of large-and medium-sized enterprises are obviously higher than those of small and micro enterprises. The PM_2.5 emissions of catering enterprises are mainly attributed to high emission loads of large enterprises and those for a large number of small and medium enterprises. The PM_2.5 emission inventory of cooking in Shanghai was calculated according to the three emission factors above, and the results were very close. Therefore, the method for estimating the PM_2.5 emission inventory for cooking presented in this study is helpful for other Chinese cities to calculate their PM_2.5 emission inventory from cooking.

[Chemical Characterization, Spatial Distribution, and Source Identification of Organic Matter in PM2.5 in summertime Shanghai, China]

Particulate organic matter (POM) has attracted increasing attention recently due to its great contribution to fine particles (PM_2.5) and complex components and sources. In the present study, 78 particulate organic compounds in PM_2.5 were quantified at three sites in Shanghai during summer; these sites were located in urban (Xuhui), suburban (Qingpu), and coastal (Lin'gang) areas of the city. Accordingly, the chemical composition and spatial distribution were investigated and sources were explored based on the indicators and diagnostic ratios combined with backward trajectory. The results showed that during the period of observation, the quantified organic matter in the suburban area is about 319 ng ·m^-3, close to the urban area but much higher than that of the coastal areas. Fatty acids were the largest contributors, followed by levoglucosan, polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and hopanes. Source analysis based on tracer methods indicates that gasoline vehicle emissions were the main source of POM in Shanghai. Biomass burning from the northeast impacted somewhat on the urban area and western suburbs during the observation period. Terrestrial plant emissions played an important role in the source of fatty acids at Qingpu and Lin'gang, and emissions of marine phytoplankton and microorganisms were also important for fatty acids at Lin'gang. Coal combustion and motor vehicle exhaust made an important contribution to PAHs according to an analysis of diagnostic ratios. This study presented the characteristics and sources of POM in summertime Shanghai, which facilitates the development of an effective control strategy on PM_2.5 pollution.

[Study on the relationship between ultrasonographic features of papillary thyroid carcinoma and central cervical lymph node metastasis]

Objective: To investigate the correlation between ultrasonographic features of papillary thyroid carcinoma and central cervical lymph node metastasis. Methods: We retrospectively analyzed 486 patients with papillary thyroid carcinoma(PTC), pathologically confirmed after surgery in Tianjin Medical University Cancer Institute & Hospital. All patients were divided into central cervical lymph node metastasis group and non-metastasis group. No lateral cervical lymph node metastasis was found in preoperative ultrasonography and postoperative pathology. The characteristics of the ultrasound was observed and analyzed. Results: 297 out of 486 patients with papillary thyroid carcinomahad central metastasis, and the other 189 cases did not. Take pathology results as a standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate of preoperative ultrasound diagnosis in PTC patients with central cervical lymph node metastasis were 35.3%, 88.6%, 83.2%, 47.4%, 56.6%, respectively. Univariate analysis showed that multi-focus, taller-than-wide, diameter>1 cm, located in the lower pole, ill-defined margin, hypoechogenicity, micro-calcification, capsule invasion more than 1/4 perimeter of papillary thyroid carcinoma were significantly associated with central cervical lymph node metastasis (all P<0.05). Multivariate analysis showed that diameter>1 cm, micro-calcification, capsule invasion more than 1/4 perimeter of papillary thyroid carcinoma became independent risk factors of central cervical neck lymph node metastasis (all P<0.05). Conclusions: Preoperative description of ultrasonographical features has important value to assess central cervical lymph node metastasis in patients with papillary thyroid carcinoma. More information could be provided for clinical treatment. When the papillary thyroid carcinoma presented as diameter>1 cm, micro-calcification, and capsule invasion more than 1/4 perimeter of, there will be a greater risk of central cervical lymph node metastasis, and we shall suggest prophylactic central lymph cervical node dissection.

Spatial Distortion of Vibration Modes via Magnetic Correlation of Impurities

Long wavelength vibrational modes in the ferromagnetic semiconductor Ga_{0.91}Mn_{0.09}As are investigated using time resolved x-ray diffraction. At room temperature, we measure oscillations in the x-ray diffraction intensity corresponding to coherent vibrational modes with well-defined wavelengths. When the correlation of magnetic impurities sets in, we observe the transition of the lattice into a disordered state that does not support coherent modes at large wavelengths. Our measurements point toward a magnetically induced broadening of long wavelength vibrational modes in momentum space and their quasilocalization in the real space. More specifically, long wavelength vibrational modes cannot be assigned to a single wavelength but rather should be represented as a superposition of plane waves with different wavelengths. Our findings have strong implications for the phonon-related processes, especially carrier-phonon and phonon-phonon scattering, which govern the electrical conductivity and thermal management of semiconductor-based devices.

[Pollutant Emissions from Diesel Buses Fueled with Waste Cooking Oil Based Biodiesel]

Two diesel buses respectively certified to meet China Ⅲ and China Ⅴ emission standards were used as prototype vehicles, fixed on a heavy-duty chassis dynamometer and driven according to a typical city bus driving cycle to analyze the pollutant emissions and volatile organic compounds (VOCs). The buses were fueled with diesel and waste cooking oil based biodiesel with 10 vol% blend ratio (B10). The emissions of total hydrocarbon(THC), CO, particulate matter (PM), and the number of solid particles with a diameter of 23 nm to 2.5 μm (referred to as "solid particulate number of PM_2.5") from the bus certified to meet China Ⅴ (referred to as "China V bus") were 39.3%, 19.9%, 77.4%, and 28.4% lower than those from the other bus certified to meet China Ⅲ (referred to as "China Ⅲ bus"), while NO_x emissions were 31.7% higher. Moreover, alkanes, alkenes, aromatic hydrocarbons, and oxygenated compounds in VOCs emitted from the China V bus were lower than those emitted from the China Ⅲ bus, suggesting lower atmospheric reactivity and smaller potential of secondary organic aerosol formation. Compared with the emission results of two diesel-fueled buses, the B10-fueled buses emitted smaller amounts of THC, CO, PM, and solid particulate number of PM_2.5, lower oxygenated compounds but higher alkenes; slightly higher NO_x emissions than China Ⅲ but slightly lower NO_x emissions than China V. Consequently, the atmospheric reactivity of VOCs in exhaust gas from the bus fueled with B10 was higher than that from the diesel-powered bus.

[Emissions, Chemical Composition, and Spatial and Temporal Allocation of the BVOCs in the Yangtze River Delta Region in 2014]

Based on the land surface vegetation data interpreted via remote sensing and the meteorological conditions predicted via the WRF model, the MEGAN model was applied to calculate the regional BVOC emissions in the Yangtze River Delta (YRD) in 2014. The chemical components and the temporal and spatial allocations were further analyzed. Results show that the annual BVOC emissions in the YRD were 1886 kt, in which isoprene emissions were 704.2 kt (accounting for 37.3%), monoterpenes 303 kt (16.1%), and other VOCs 878.8 kt (46.6%). Seasonal variation of the BVOC emissions was very significant. The BVOC emissions had a strong seasonal pattern, with maximum emissions in summer, accounting for 60.9% (1088 kt) of the total, whereas the minimum emissions occurred in winter, accounting for 3.2% (57 kt). Spatially, the southern YRD produced more BVOC emissions than the northern part did. In Zhejiang, Anhui, Jiangsu, and Shanghai, the BVOC emissions were 842 kt (44.6%), 760 kt (40.3%), 272 kt (14.4%), and 12 kt (0.7%), respectively. This is mainly related to the distribution of vegetation types.