[Research on alien invasive plants in Jingzhou County, Hunan Province, China]. / æ¹–å—çœé–å·žåŽ¿å¤–æ¥å ¥ä¾µæ¤ç‰©ç ”ç©¶.

Harm from alien invasive plants is increasing in Jingzhou County, Hunan Province. Based on a one-year field investigation and available literature, we investigated species composition, origin, flora, degree of harm and distribution pattern of invasive plants in the county. The results showed that there were 34 invasive plant species from 27 genera and 16 families in this County. The dominant invasive species belonged to Asteraceae (8 species) and Amaranthaceae (6 species), which accounted for 23.5% and 17.7%, respectively. The majority of invasive plants originated from South America (45.7%) and North America (30.4%). Tropical flora showed a significantly higher representation than temperate flora, signifying robust tropical characteristics amongst the invasive plant population. Based on hazard level classification, we recognized four types as malicious invasion (Level 1): Alternanthera philoxeroides, Erigeron annuus, E. canadensis, and Xanthium chinense. In addition, five types were classified as severe invasion (Level 2), eight types as local invasion (Level 3), fifteen types as general invasion (Level 4), while two types were still under observation (Level 5). The pattern of distribution demonstrated that invasive plants in Jingzhou County mostly spread along the verges of transportation roads, in human settlements, and in a few areas of water flow. The higher levels of invasion damage were principally concentrated in the central part of Jingzhou County.

Transcription Factor MAZ Potentiates the Upregulated NEIL3-mediated Aerobic Glycolysis, Thereby Promoting Angiogenesis in Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is characterized by high vascularity and notable abnormality of blood vessels, where angiogenesis is a key process in tumorigenesis and metastasis. The main functions of Nei Like DNA Glycosylase 3 (NEIL3) include DNA alcoholization repair, immune response regulation, nervous system development and function, and DNA damage signal transduction. However, the underlying mechanism of high expression NEIL3 in the development and progression of HCC and whether the absence or silencing of NEIL3 inhibits the development of cancer remain unclear. Therefore, a deeper understanding of the mechanisms by which increased NEIL3 expression promotes cancer development is needed. METHODS: Expression of NEIL3 and its upstream transcription factor MAZ in HCC tumor tissues was analyzed in bioinformatics efforts, while validation was done by qRT-PCR and western blot in HCC cell lines. The migration and tube formation capacity of HUVEC cells were analyzed by Transwell and tube formation assays. Glycolytic capacity was analyzed by extracellular acidification rate, glucose uptake, and lactate production levels. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter gene assays were utilized to investigate specific interactions between MAZ and NEIL3. RESULTS: NEIL3 and MAZ were substantially upregulated in HCC tissues and cells. NEIL3 was involved in modulating the glycolysis pathway, suppression of which reversed the stimulative impact of NEIL3 overexpression on migration and angiogenesis in HUVEC cells. MAZ bound to the promoter of NEIL3 to facilitate NEIL3 transcription. Silencing MAZ reduced NEIL3 expression and suppressed the glycolysis pathway, HUVEC cell migration, and angiogenesis. CONCLUSION: MAZ potentiated the upregulated NEIL3-mediated glycolysis pathway and HCC angiogenesis. This study provided a rationale for the MAZ/NEIL3/glycolysis pathway as a possible option for anti-angiogenesis therapy in HCC.

Oligomer formation from cross-reaction of Criegee intermediates in the styrene-isoprene-O3 mixed system.

Alkene ozonolysis can produce stabilized Criegee intermediates (SCIs), which play a key role in oligomers' formation. Though styrene and isoprene coexist in the ambient atmosphere as important anthropogenic and biogenic secondary organic aerosol (SOA) precursors, respectively, their cross-reactions have not received attention. This study investigated the interactions of SCIs from styrene and isoprene ozonolysis for the first time. The high-resolution Orbitrap mass spectrometer was used to determine the unique ion mass spectra of the isoprene-styrene-O3 mixture. The results show that the signal intensities of new ions account for >8.4% of total ions in the mass spectra of the styrene-isoprene-O3 mixed system. Styrene and isoprene ozonolysis can produce characteristic C7-SCI and C4-SCI, respectively. C7-SCI and C4-SCI can be involved in the cross-reactions, and the results of tandem mass spectra directly confirmed both C7-SCI and C4-SCI as chain units. The O/C and H/C ratios of cross-products are in the range of 0.38-1.07 and 1.00-1.50, respectively, which are consistent with cross-reaction products. Adding a C7-SCI unit reduces the oligomer's volatility by 1.3-1.4 orders of magnitude lower than adding a C4-SCI unit. Thus, C4-SCI can compete with C7-SCI to react with styrene-derived RO2/RC(O)OH to produce more volatile cross-products, while the less volatile cross-products can be formed when isoprene-derived RO2/RC(O)OH reacted with C7-SCI instead of C4-SCI. The SOA yield of the mixed system is lower than that of the single styrene-O3 system but higher than that of the single isoprene-O3 system. Ambient particles were also collected, and 5 possible SCI-related cross-products were identified. This study illustrates the effects of SCI-related cross-reactions on SOA components and physicochemical properties, providing a basis for future research on SCI-related cross-reactions that frequently occur in the ambient atmosphere.

Experimental and numerical investigation on failure mechanism of expansive soil subgrade slope.

Shallow landslides of expensive soil slopes occur from time to time, and most engineering geological problems are directly or indirectly caused by soil structure cracks. The existence of tensile cracks can significantly affect the hydro-mechanical properties of soils. In this paper, the mechanism of expansive soil landslide formation is explored, and swelling pressures, and drying and wetting cycles are introduced into the discrete element method (DEM), and the landslide process of expansive soils is studied by the numerical simulation mothed. The relationship between the crack development and the instability of expansive soil slopes was investigated. The results show that under the condition of seasonal dry and wet alternation, the cracks of the expansive soil slope gradually develop, the rainwater infiltrates rapidly, the mechanical properties gradually deteriorate, and under the effect of such adverse cycle, the soil gradually softens and the stability decreases. Under the influence of human activities, vehicle loads and other factors, the slope body slides. These findings are helpful for the design and construction of expansive soil slopes and foundations.

Explosive formation of secondary organic aerosol due to aerosol-fog interactions.

Aerosol particles can profoundly affect the local environment and global climate. Explosive growths of secondary organic aerosol (SOA) are frequently observed during serious haze evens, but their fundamental mechanism remains unclear. We used chamber experiments and kinetic model simulations to reveal the microphysical mechanism for explosive organic aerosol formation. The evolution of SOA with organic vapors under dry and highly humid conditions was determined based on a high-resolution Orbitrap mass spectrometer. We found that the condensation of gas-phase organics could lead to the formation of cloud or fog droplets with relative humidity below 100 %; meanwhile, the aerosol-fog interaction could result in the explosive growth of SOA. Monomeric products from toluene oxidation were verified to primarily contribute to the increased SOA in super humid conditions, which are mainly assigned to be intermediate- and semi-volatile organic compounds. Moreover, we demonstrated that the decreasing temperatures could dramatically amplify organic compounds' co-condensing influence on SOA explosive formation and activation at relative humidity above 85 % and temperature below 20 °C. Our findings revealed that aerosol-fog interaction is the fundamental driving force for explosive organic aerosol formation. It indicates that overlooking the co-condensation of organic vapors with water could significantly underestimate SOA and liquid water content in 3D models.

SNHG3 regulates NEIL3 via transcription factor E2F1 to mediate malignant proliferation of hepatocellular carcinoma.

The involvement of small nucleolar RNA host gene 3 (SNHG3) in cancer regulation has been reported. This study attempted to deeply investigate the molecular regulatory mechanism of SNHG3 on malignant progression of hepatocellular carcinoma (HCC). According to TCGA analysis, high SNHG3 expression was a risk factor for poor prognosis of HCC patients. Therefore, we further detected the mRNA level of SNHG3 in HCC tissue and cells. It was found that SNHG3 was upregulated in HCC tissue and cells. Afterwards, CCK-8 and flow cytometry assays further proved that silencing SNHG3 inhibited HCC cell proliferation while inducing cell apoptosis and G0/G1 phase arrest. It was also attested in vivo experiments that silencing SNHG3 could reduce the volume and weight of tumors and downregulate the Ki-67 expression to suppress HCC tumor growth. Next, it was discovered that SNHG3 increased the binding of E2F1 and NEIL3 promoter region, thereby activating the transcription feature of NEIL3. Lastly, rescue assays indicated that NEIL3 participated in SNHG3-mediated HCC cell cycle, apoptosis and proliferation. All in all, this study revealed the specific regulatory mechanism of SNHG3 in HCC to enable SNHG3 a hopeful marker for HCC diagnosis and treatment.

Formation of extremely low-volatility organic compounds from styrene ozonolysis: Implication for nucleation.

Styrene is a highly reactive compound with the dual nature of aromatics and olefins. This work presents evidence for formation of extremely low-volatility organic compounds (ELVOCs) from styrene ozonolysis. The molecules of ELVOCs were analyzed using a high-resolution orbitrap mass spectrometer. The results show that ELVOCs were oligomers characterized by stabilized Criegee radicals (SCIs) as chain units. The addition of C6H5CHOO (SCI1) or CH2OO (SCI2) can dramatically decrease the oligomers' volatility. At low relative humidity (RH), ELVOCs are mainly formed from the reaction of RO2 radical, C6H5OO·, with SCI1 and SCI2; however, ELVOCs are primarily produced by the reaction between benzoic acid and SCI1 at high RH. Ambient particles were also collected to propose the probable oligomers from styrene-SCI. Our results suggest that styrene-SCI derived ELVOCs may act as nucleating agents, potentially providing an experimental basis for nucleation events that frequently occur in urban areas.

Wall losses of oxygenated volatile organic compounds from oxidation of toluene: Effects of chamber volume and relative humidity.

Vapor wall losses can affect the yields of secondary organic aerosol. The effects of surface-to-volume (S/V) ratio and relative humidity (RH) on the vapor-wall interactions were investigated in this study. The oxygenated volatile organic compounds (OVOCs) were generated from toluene-H2O2 irradiations. The average gas to wall loss rate constant (kgw) of OVOCs in a 400 L reactor (S/V = 7.5 m-1) is 2.47 (2.41 under humid conditions) times higher than that in a 5000 L reactor (S/V = 3.6 m-1) under dry conditions. In contrast, the average desorption rate constant (kwg) of OVOCs in 400 L reactor is only 1.37 (1.20 under humid conditions) times higher than that in 5000 L reactor under dry conditions. It shows that increasing the S/V ratio can promote the wall losses of OVOCs. By contrast, the RH effect on kgw is not prominent. The average kgw value under humid conditions is almost the same as under dry conditions in the 400 L (5000 L) reactor. However, increasing RH can decrease the desorption rates. The average kwg value under dry conditions is 1.45 (1.27) times higher than that under humid conditions in the 400 L (5000 L) reactor. The high RH can increase the partitioning equilibrium timescales and enhance the wall losses of OVOCs.

OMI formaldehyde column constrained emissions of reactive volatile organic compounds over the Pearl River Delta region of China.

In recent years, surface ozone (O3) concentration was high and became the primary air pollutant in the Pearl River Delta (PRD) region. However, as precursors of tropospheric O3, the emissions of reactive nonmethane volatile organic compounds (NMVOCs) were reported to have large uncertainties. Here, combined with the simulated formaldehyde (HCHO) columns from the RAMS-CMAQ modeling system, formaldehyde (HCHO) columns derived from the Ozone Monitoring Instrument (OMI) were used as the constraints to improve the emission estimates of the reactive NMVOCs through the linear regression method over the PRD region in March of 2017. The observed highest HCHO concentration was 2-4 times as high as the original simulated results over the PRD region mostly due to the underestimation in the reactive NMVOC emissions, especially the anthropogenic sources. With the regression coefficients calculated through five sensitivity simulation cases as well as the observed HCHO column, the better quantified emissions of reactive NMVOCs were obtained over the PRD region. It showed that the total emissions of reactive NMVOCs were improved by a factor of 2.1. The emissions derived from anthropogenic, biomass burning and biogenic sources increased from 0.0329, 4.69 × 10-4 and 0.0524 Tg/month to 0.0959, 0.0215 and 0.0620 Tg/month, respectively. As a result, the difference between the observed and modeled high HCHO column decreased to 1-2.5 times, which may be dominated by the enhanced reactive NMVOC emissions derived from anthropogenic sources. Besides, the great improvement in the emissions of reactive NMVOCs contributed to an increase of 20-40 µg/m3 in the maximum daily 8-h average (MDA8) O3 concentration over the PRD region.

Cracking propagation in expansive soils under desiccation and stabilization planning using Bayesian inference and Markov decision chains.

Desiccation cracking endangers the stability of expansive soils subjected to cyclic moisture variations. In the current research, prominent cracking prediction models including linear, linear elastic, linear elastoplastic, and linear elastic fracture were studied. Then, Monte Carlo limit state functions were generated based on predictions. Results indicate that there is less than 5% chance of cracking for depths beyond 0.5, 6, 8, and 9 m as predicted by the linear elastoplastic, linear elastic, linear, and linear elastic fracture models, respectively. Moreover, a series of sensitivity analysis was performed to evaluate model and parameter uncertainties. Comparatively, it was found that the linear model exhibits the highest uncertainty while linear elastoplastic model possesses the least uncertainty thus yielding a reasonable prediction. Additionally, soil parameters including matric suction followed by dry density were identified to govern the overall cracking. Using Bayesian inference, numerous conditional probabilities of variation of soil properties were investigated. Then, several cracking probabilities under history of low to high matric suction and dry density were obtained. Accordingly, Monte Carlo Markov decision chains were established based on several ecofriendly and feasible stabilization policies and their performance was also evaluated. The obtained safety factors (SF) suggest that stabilization plans resulting in high moisture and dry density have the least likelihood of cracking with a SF equal to 5.1. However, stabilization policies having low dry density and moisture yield have the least SF of 0.39. Findings of this study can improve the decision-making processes for expansive soil stabilization by considering a variety of environmental conditional probabilities.

The bZIP Transcription Factor ZIP-11 Is Required for the Innate Immune Regulation in Caenorhabditis elegans.

Innate immunity is the first line of host defense against pathogen infection in metazoans. However, the molecular mechanisms of the complex immune regulatory network are not fully understood. Based on a transcriptome profiling of the nematode Caenorhabditis elegans, we found that a bZIP transcription factor ZIP-11 was up-regulated upon Pseudomonas aeruginosa PA14 infection. The tissue specific RNAi knock-down and rescue data revealed that ZIP-11 acts in intestine to promote host resistance against P. aeruginosa PA14 infection. We further showed that intestinal ZIP-11 regulates innate immune response through constituting a feedback loop with the conserved PMK-1/p38 mitogen-activated protein signaling pathway. Intriguingly, ZIP-11 interacts with a CCAAT/enhancer-binding protein, CEBP-2, to mediate the transcriptional response to P. aeruginosa PA14 infection independently of PMK-1/p38 pathway. In addition, human homolog ATF4 can functionally substitute for ZIP-11 in innate immune regulation of C. elegans. Our findings indicate that the ZIP-11/ATF4 genetic program activates local innate immune response through conserved PMK-1/p38 and CEBP-2/C/EBPγ immune signals in C. elegans, raising the possibility that a similar process may occur in other organisms.

Lesion human leukocyte antigen-E is associated with favourable prognosis for patients with oesophageal squamous cell carcinoma.

OBJECTIVE: To investigate the clinical significance of human leukocyte antigen (HLA)-E levels in oesophageal squamous cell carcinoma (ESCC). METHODS: The levels of HLA-E immunostaining in ESCC lesions and 47 corresponding adjacent normal tissues were measured using immunohistochemistry. The correlation between the levels of immunostaining and clinical parameters was analysed. RESULTS: This study analysed 110 paraffin-embedded primary tumour lesions and 47 case-controlled paracancerous tissues that were surgically resected from 110 patients with ESCC. Positive immunostaining for HLA-E was observed in 88.2% (97 of 110) of ESCC lesions and 29.8% (14 of 47) of normal oesophageal tissues. There was no correlation between HLA-E immunostaining in ESCC lesions and clinicopathological characteristics such as lymph node metastasis, tumour-node-metastasis stage and differentiation grade. Kaplan-Meier survival analysis revealed a significantly better prognosis in patients with higher levels of HLA-E immunostaining than in those with lower levels of HLA-E immunostaining; overall survival was 28.6 months (95% confidence interval [CI], 23.2, 34.0) versus 15.3 months (95% CI, 11.5, 19.1), respectively. Furthermore, multivariate analysis showed that the HLA-E level was an independent prognostic factor in patients with ESCC. CONCLUSION: A higher level of HLA-E immunostaining was associated with favourable survival in patients with ESCC.

A core-shell box model for simulating viscosity dependent secondary organic aerosol (CSVA) and its application.

Secondary organic aerosol (SOA) plays a key role in air pollution and global climate change. However, the understanding and modelling of SOA properties and evolution are still limited. In this paper, we developed a novel kinetic Core-Shell box model for Viscosity dependent SOA simulation (CSVA), which includes explicit gas-phase reactions (MCM), homogeneous nucleation by H2SO4-NH3-H2O, viscosity dependent mass transfer between gas and particle phases (organic and aqueous phases) and particle-phase reactions. The gas-particle mass transfer is represented by chainlike reactions analogizing to electrical resistance. The CSVA model is verified and applied to chamber experiments of toluene oxidation systems. The monomers and dimers of SOA are determined by coupling the high-resolution Orbitrap mass spectra and MCM mechanism. The majority of dimers are confirmed to be peroxyhemiacetals formed by reactions of hydroperoxides with aldehydes in the particle phase. The results show that CSVA can well capture the following processes: (1) relative humidity (RH) dependent nucleation of the H2SO4-NH3-H2O system, (2) particle size-dependent hygroscopic growth of inorganics (e.g., NaCl and (NH4)2SO4) and organics (levoglucosan and SOA), (3) NOx dependent SOA formation, (4) viscosity-induced evolution of particle size distribution, and (5) effect of RH on SOA formation. In particular, our model reproduces the phenomenon that the evolution of SOA particle size distribution from a one-peak mode into a two-peak mode is due to viscosity.

Fractal approach in expansive clay-based materials with special focus on compacted GMZ bentonite in nuclear waste disposal: a systematic review.

Knowledge of the behavior of highly compacted expansive clays, as an engineered barrier, in disposal of high-level nuclear waste (HLW) systems to prevent the pollution due to migration of radionuclide is extremely essential. The prominent properties of globally and widely used bentonites have been extensively studied during past two decades. In China, GaoMiaoZi (GMZ) bentonite is the first choice as a buffer or backfill material for deep geological repositories. This review article presents the recent progresses of knowledge on water retention properties, hydromechanical behavior, and fractal characteristics of GMZ bentonite-based materials, by reviewing 217 internationally published research articles. Firstly, the current literature regarding hydrogeochemical and mechanical characteristics of GMZ bentonite influenced by various saline solutions are critically summarized and reviewed. Then, the role of osmotic suction π alongside the application of surface fractal dimension Ds is presented from the standpoint of fractal theory. Finally, the strength characteristics of GMZ bentonites using fractal approach have been discussed. Furthermore, this study sheds light on gaps, opportunities, and further research for understanding and analyzing the long-term hydromechanical characteristics of the designed backfill material, from the standpoint of surface fractality of bentonites, and implications of sustainable buffer materials in the field of geoenvironmental engineering.

RNA polymerase II subunit 3 regulates vesicular, overexpressed in cancer, prosurvival protein 1 expression to promote hepatocellular carcinoma.

OBJECTIVE: To explore the relationships between hepatocellular carcinoma (HCC) and the expression of RNA polymerase II subunit 3 (RPB3) and vesicular, overexpressed in cancer, prosurvival protein 1 (VOPP1), and to determine whether RPB3 regulates VOPP1 expression to promote HCC cell proliferation, tumor growth, and tumorigenesis. METHODS: HCC and adjacent liver samples were collected from 51 patients with HCC who underwent surgical excision between September 20, 2010 and June 22, 2017. Immunohistochemical staining, western blot, quantitative PCR, plate colony assay, and RNA microarray were used to detect relevant indexes for further analyses. RESULTS: VOPP1 was shown to function as a target gene of RPB3 in facilitating HCC proliferation, and was downregulated after RBP3 silencing. Additionally, hepatic tumor tissues demonstrated high VOPP1 expression. Furthermore, VOPP1 silencing suppressed tumor growth and cell proliferation and elicited apoptosis. CONCLUSION: RPB3 regulates VOPP1 expression to promote HCC cell proliferation, tumor growth, and tumorigenesis.

Predictive modeling of swell-strength of expansive soils using artificial intelligence approaches: ANN, ANFIS and GEP.

This study presents the development of new empirical prediction models to evaluate swell pressure and unconfined compression strength of expansive soils (PsUCS-ES) using three soft computing methods, namely artificial neural networks (ANNs), adaptive neuro fuzzy inference system (ANFIS), and gene expression programming (GEP). An extensive database comprising 168 Ps and 145 UCS records was established after a comprehensive literature search. The nine most influential and easily determined geotechnical parameters were taken as the predictor variables. The network was trained and tested, and the predictions of the proposed models were compared with the observed results. The performance of all the models was tested using mean absolute error (MAE), root squared error (RSE), root mean square error (RMSE), Nash-Sutcliffe efficiency (NSE), correlation coefficient (R), regression coefficient (R2) and relative root mean square error (RRMSE). The sensitivity analysis indicated that the increasing order of inputs importance in case of Ps followed the order: maximum dry density MDD (30.5%) > optimum moisture content OMC (28.7%) > swell percent SP (28.1%) > clay fraction CF (9.4%) > plasticity index PI (3.2%) > specific gravity Gs (0.1%), whereas, in case of UCS it followed the order: sand (44%) > PI (26.3%) > MDD (16.8%) > silt (6.8%) > CF (3%) > SP (2.9%) > Gs (0.2%) > OMC (0.03%). Parametric analysis was also performed and the resulting trends were found to be in line with findings of past literature. The comparison results reflected that GEP and ANN are efficacious and reliable techniques for estimation of PsUCS-ES. The derived mathematical GP-based equations portray the novelty of GEP model and are comparatively simple and reliable. The Roverall values for PsUCS-ES followed the order: ANN > GEP > ANFIS, with all values lying above the acceptable range of 0.80. Hence, all the proposed AI approaches exhibit superior performance, possess high generalization and prediction capability, and evaluate the relative importance of the input parameters in predicting the PsUCS-ES. The GEP model outperformed the other two models in terms of closeness of training, validation and testing data set with the ideal fit (1:1) slope. Evidently the findings of this study can help researchers, designers and practitioners to readily evaluate the swell-strength characteristics of the widespread expansive soils thus curtailing their environmental vulnerabilities which leads to faster, safer and sustainable construction from the standpoint of environment friendly waste management.

Model analysis of meteorology and emission impacts on springtime surface ozone in Shandong.

Air quality observations showed that surface ozone (O3) concentrations over Shandong increased significantly in springtime in recent years, especially 2017. The observed 90th percentile of hourly O3 concentrations (O3-h_90) in May increased from 148.4 µg/m3 in 2016 to 176.2 µg/m3 in 2017. To investigate the reasons of significant increase of O3 in spring of 2017, seven sensitivity cases were performed with the RAMS-CMAQ modeling system to identify the impacts of meteorological conditions (M) and emissions (E) on O3 concentrations in May of Shandong during the time period 2016-2018. The regional O3-h_90 in May of Shandong were 103.0, 120.3 and 86.3 µg/m3 in 2016, 2017 and 2018, respectively. It was found that the positive effects from favorable meteorology were the dominant reasons that resulted in the high O3 concentration in May 2017. When compared to 2017 standard simulation (17E17M), the differences of meteorological conditions led to the decrease of 17.5 and 33.8 µg/m3 in regional O3-h_90 of May in 2016 (17E16M) and 2018(17E18M), while small changes (0.6 and - 0.3 µg/m3) appeared in that of May 2016 (16E17M) and 2018(18E17M) due to emission differences. Since there were few differences in the wind speeds of May between three years, the higher temperature and lower relative humidity significantly contributed to O3 formation in May 2017 compared to May of 2016 and 2018. Besides, the amount of cloud fraction (CF), which has an indirect influence on the surface temperature and photochemical production of ozone by its impacts on the insolation, was the least in May 2017 compared to that in May 2016 and 2018 over Shandong. The distributions of changes in CF had obvious negative correlations with that of O3 vertical column concentrations and temperature. Thus, the fewer cloud fraction may play a key role in O3 formation of May 2017.

Laparoscopic cholecystectomy with two incisions: an improved, feasible and safe technique with superior cosmetic outcomes.

OBJECTIVE: Conventional laparoscopic cholecystectomy (CLC) is usually performed with four incisions. Minimally invasive surgery for gallbladder disease with less pain and smaller scars has become increasingly popular. This study reported a new, two-incision laparoscopic cholecystectomy (TILC) using conventional instruments. METHODS: In this prospective study, 43 patients were recruited to undergo TILC and were compared with 43 historical cases undergoing CLC. We evaluated operative time, postoperative pain, cosmesis and complications. RESULTS: There was no significant difference in gender, age, body mass index, bile duct damage, blood loss and postoperative hospital stay between the two groups. The mean operation time was longer with TILC than with CLC, but the difference was not statistically different. Postoperative pain scores were significantly lower with TILC than with CLC. The mean cosmetic satisfaction score was significantly higher with TILC than that with CLC. There was no significant difference in the incidence of complications between the two groups. CONCLUSION: Our work demonstrates that TILC generates less postoperative pain and significantly improved cosmesis for patients. TILC is a safe and feasible alternative to CLC.

The role of functional groups in the understanding of secondary organic aerosol formation mechanism from α-pinene.

The infrared spectra (IR) analysis in combination with electrospray ionization high-resolution orbitrap mass spectra (ESI-HRMS) can provide new insight into the overall structural feature and specific molecules of secondary organic aerosol (SOA). In this study, the functional group signature of SOA produced from OH and O3 channel oxidation of α-pinene is characterized based on the IR and ESI-HRMS. The IR spectra of SOA from the OH channel show strong absorptions of hydrogen bonded OH groups and weak absorptions of CO groups, while the absorptions of CO are more abundant than OH in the O3 channel. A linear relationship between the ratio of functional group absorption area (SO-H/SC=O) and the group number ratio of nO-H/nC=O is obtained. The ratios of nO-H/nC=O in the O3 and H2O2 systems of SOA are estimated to be 0.60 and 3.91, respectively. The ESI-HRMS results show that organic acids are the major products in both the O3 and NO2 systems. In contrast to the O3 channel, alcohols are more abundant from the OH channel. The major compounds of SOA from the H2O2 system are confirmed to be formed by autoxidation of first generation RO2 radicals. The nO-H/nC=O ratio obtained by IR is in good agreement with that by MS. Thus, the ratio of nO-H/nC=O can be used to characterize SOA formation from different oxidation channels. In α-pinene-NO2 irradiations, the ratio of nO-H/nC=O is 0.83, which is quite close to that from the O3 system, but totally different from that in the H2O2 system. This strongly supports that the O3 channel plays a key role in the formation of SOA from the α-pinene-NO2 system. The similarity of both products and the nO-H/nC=O ratios between the α-pinene-O3 and α-pinene-NO2 systems strongly states that a stabilized Criegee intermediate (SCI) is a key factor controlling SOA formation.

Molecular composition and sources of water-soluble organic aerosol in summer in Beijing.

Water-soluble organic aerosol (WSOA) constitutes a large fraction of OA and plays an important role in formation of secondary OA (SOA). Here we characterized the sources and molecular composition of WSOA in summer in Beijing using high-resolution aerosol mass spectrometer and orbitrap mass spectrometer equipped with electrospray ionization. Our results showed that WSOA was the major fraction of OA on average accounting for 69% in summer, which is much higher than that (47%) in winter. However, the oxidation degree of WSOA was comparable between summer and winter (O/C = 0.62 vs. 0.63). Positive matrix factorization analysis showed that SOA contributed dominantly to WSOA (72%) indicating that WSOA was mainly from secondary formation. The two water-soluble SOA factors that are associated with regional processing (OOA-1) and photochemical production (OOA-2), respectively, showed very different behaviors throughout the study. OOA-2 showed much enhanced contribution during polluted periods with low relative humidity (RH), while OOA-1 played a more important role during high RH periods. Molecular composition analysis of WSOA revealed a high diversity of CHO (compounds only containing carbon, hydrogen and oxygen) and CHOS (sulfur-containing organics) in WSOA in summer. Particularly, the relative intensity fraction of CHOS- compounds was increased by 42% from clean to polluted days which was associated with large increases (20%) in organosulfates (OSs) with lower O∗/C (0.1-0.4), and OOA-1. These results suggest the formation of more unsaturated OSs in OOA-1 during polluted days in summer. Comparatively, the biogenic-derived OSs remained relatively stable (24-31%) for the entire study highlighting the ubiquitous importance of biogenic SOA in summer.