乙烯原料最适裂解温度研究

采用裂解炉标定方法,探究气体、石脑油、加氢尾油三种原料在不同裂解温度下的产品分布,选取最佳经济效益点,同时考虑高附产品收率相对较好,兼顾对应温度下裂解炉运行周期,得出最适宜温度。经数据分析,在以经济效益最大化为前提,兼顾高附收率以及运行周期条件下,确定1^(#)裂解炉裂解气体最佳温度在860℃;6^(#)裂解炉裂解加氢尾油最佳温度在810℃,此时丙/乙比0.6;确定7^(#)裂解炉裂解石脑油最佳温度在845℃,此时丙/乙比0.56。

Investigation on specific heat capacity and thermal behavior of sodium hydroxyethyl sulfonate

The thermal decomposition process was studied by the TG–DTA analyzer. The results show that the decomposition process of sodium hydroxyethyl sulfonate consisted of three stages: the mass loss for the first, the second and third stages may be about the groups of CH_3CH_2OH, CH_3CHO and SO_2 volatilized, respectively. The decomposition residuum of three stages was analyzed by FT-IR, and the results of FT-IR agreed with the decomposition process predicted by theoretical weight loss. The specific heat capacity of sodium hydroxyethyl sulfonate was determined by differential scanning calorimetry(DSC). The melting temperature and melting enthalpy were obtained to be 465.41 K and 25.69 kJ·mol^(-1), respectively. The molar specific heat capacity of sodium hydroxyethyl sulfonate was determinated from 310.15 K to 365.15 K and expressed as a function of temperature.

Clinical features of adverse reactions associated with telbivudine

AIM: To analyze the clinical features and risk factors of adverse reactions associated with telbivudine. METHODS: Clinical data were collected from cases that presented with serious adverse reactions to telbivudine. We analyzed general information and medicine status, clinical features, results of examination, and misdiagnosis. RESULTS: Out of 105 patients who were treated with telbivudine for hepatitis B in an outpatient department from January, 2007 to January, 2008, five presented with serious adverse drug reactions. Most of these five patients had used other nucleoside analogues in the past. Four were treated with a combination of telbivudine and interferon or another nucleoside analogue, while the other received an increased dose of telbivudine. The main adverse reactions were myalgia and general weakness. This was accompanied by cardiac arrhythmia in one patient, and nervous symptoms in three. Serum creatine kinase was elevated. The rate of misdiagnosis was high. CONCLUSION: The adverse reactions were related to telbivudine, but the biological mechanism of the reactions is not yet clear. Combination therapy with interferon or another nucleoside analogue and a high dose may increase the risk of adverse reactions.

Randomized comparison of lobaplatin plus etoposide and cisplatin plus etoposide chemotherapy in patients with extensive-stage small cell lung cancer

Objective： To compare the efficacy and safety of Lobaplatin plus Etoposide （EL） and Cisplatin plus Etoposide （EP） regimens in chemonaive with extensive-stage small-cell lung cancer （SCLC）. Methods： Between July 2010 and July 2011, a total of 62 patients with extensive-stage small-cell lung cancer who received initial treatment in our hospital and 309 hospital of PLA. 31 patients were randomly assigned to the EL Group： Lobaplatin was given intravenously at a dose of 30 mg/m2 on day 1 and Etoposide 100 mg/m2 on days 1 to 3 of 21-day cycles for a maximum of six cycles. Another 31 patients were assigned to the EP Group： Cisplatin was given intravenously at a dose of 75 mg/m2 on day 1 and Etoposide 100 mg/m2 on days 1 to 3 of 21-day cycles for a maximum of six cycles. We evaluated the efficacy, overall response rate （ORR）, disease control rate （DCR）, the progression-free survival （PFS） and toxicity between the patients of the two groups. Results： All 62 patients were eligible. In the EL group, 2 （6.5%） patients had complete response, 20 （64.5%） patients had partial response, 5 （16.1%） patients had stable disease and 4 （12.9%） patients had progress disease. In the EP group, 2 （6.5%） patients had complete response, 22 （70.9%） patients had partial response, 4 （12.9%） patients had stable disease and 3 （9.7%） patients had progress disease. The ORR of EL and EP group were 70.9% and 77.4%, respectively, showing no significant difference （P = 0.562）. The DCR of both groups were 87% and 90%, respectively, showing no significant difference （P = 0.688）. Median PFS of patients with EL and EP regimens were 5.5 months and 5 months, respectively, showing no significant difference （P = 0.637）. Adverse events were observed in all 62 patients. Grade 1 to 4 anemia was higher in the EP group than in EL group, showing significant difference （P = 0.02）. Grade 3 and 4 thrombocytopenia was seen in 4 patients （12.9%） in EL group and 1 patient （3.2%） in EP group. Although one patient had platelet transfusion owing to Grade 4 thrombocytopenia in EL group, no significant difference （P = 0.637） were shown. The incidence of nausea/vomiting was higher in the EP group than in the EL group （96.7% vs 51.6%, P = 0.00）. Conclusien： The EL regimen is an effective and low-toxicity chemotherapy and no inferior to EP regimen in treatment response, therefore, EL regimen maybe is a good choice for patients with extensive-stage SCLC.

Efficacy compared between entecavir and adefovir dipivoxil on HBeAg-positive nucleos(t)ide-naive patients with chronic hepatitis B at week 12 and week 48

Objective:To evaluate the efficacy of entecavir and adefovir dipivoxil on HBeAg-positive nucleos(t)ide-naive patients with chronic hepatitis B with the method of Meta analysis.Methods:We searched PUBMED,EMBASE,CNKI (China National Knowledge Infrastructure),the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews with reference to all data documented before May 2010.The dosage of entecavir and adefovir dipivoxil was 0.5 mg/d and 10 mg/d,respectively.Heterogeneity was examined by Chi-square test,the relative risk calculated and forest plot drawn.Rates of undetected serum HBV DNA,serum alanine aminotransferase (ALT) normalization,HBeAg clearance,HBeAg seroconversion and adverse effect occurrence were analyzed.Results:Six articles were included,which fit well in with this study.Meta analysis showed that the rate of undetected serum HBV DNA(P=0.000 2 at week 12,P=0.002 at week 48)and that of serum ALT normalization(P=0.04 at week 12,P=0.008 at week 48)in the entecavir group were higher than those in the adefovir dipivoxil group.However,no statistic significance existed between the two groups in the rate of HBeAg clearance (P=0.17),the rate of HBeAg seroconversion(P=0.53)or the rate of adverse effect occurrence(P=0.92)at week 48.Conclusion:Entecavir was superior to adefovir dipivoxil in decreasing serum HBV DNA and normalizing serum ALT in the HBeAg-positive nucleos(t)ide-naive patients with chronic hepatitis B.

Effect of inlet temperature and equivalence ratio on HCCI engine performance fuelled with ethanol:Numerical investigation

A numerical model is presented to investigate the performance of homogeneous charge compression ignition(HCCI) engines fueled with ethanol. Two approaches are studied. On one hand, two-step reaction mechanisms with Arrhenius reaction rates are implemented in combustion chemistry modeling. On the other hand, a reduced mechanism containing important reactions of ethanol involving heat release rate and reaction rates compatible with experimental data is employed. Since controls of combustion phenomenon and ignition timing are the main issues of these engines, the effects of inlet temperature and equivalence ratio as the controlling factors on the operating parameters such as ignition timing, burn duration, in-cylinder temperature and pressure of HCCI engines are explored. The results show that the maximum predicted pressures for thermodynamic model are about 71.3×10~5 Pa and 79.79×10~5 Pa, and for chemical kinetic model, they are about 71.48×10~5 Pa and 78.123×10~5 Pa, fairly comparable with corresponding experimental values of 72×10~5 Pa and 78.7×10~5 Pa. It is observed that increasing the initial temperature advances the ignition timing, decreases the burn duration and increases the peak temperature and pressure. Moreover, the maximum temperature and pressure are associated with richer mixtures.

Comparative Proteomics Analysis of the Sieve Tube from Rubber Tree(Hevea brasiliensis) Seedlings under Contrasting Ethylene Treatments

[Objective]To elucidate the role of ethylene(ET),a latex yield stimulant of the rubber tree,on the sieve tube(ST)transport efficiency of materials(especially sucrose)needed for natural rubber biosynthesis.[Method]Rubber tree seedlings were treated with ET solution or water which was used as a control on the bark,and latex samples and ST tissue samples were collected for proteomic analyses and latex sucrose content determination respectively.[Results]After ET treatment,the sucrose content of the latex was found significantly decreased.A total of 66 ethylene-responsive proteins(ERPs)were distinguished by two-dimensional gel electrophoresis(2-DE),and 54 were successfully identified by MALDI-TOF/TOF and database searching.The majority of these ERPs were involved in carbohydrate transport and metabolic processes in the ST.[Conclusion]Our findings suggest that the application of ET may increase the transport efficiency of the ST and that the application of ET promotes the consumption of energy and sucrose in the ST.

Meta-Analysis of Trials Comparing Gemcitabine and Pegylated Liposomal Doxorubicin for Treatment in Women with Progressive or Recurrent Ovarian Cancer

OBJECTIVE To evaluate the efficacy and adverse effects ofgemcitabine versus pegylated liposomal doxorubicin in patientswith progressive or recurrent ovarian cancer.METHODS We conducted a systematic literature search toidentify all randomized controlled trials comparing gemcitabineand pegylated liposomal doxorubicin for progressive orrecurrent ovarian cancer. Trial data were reviewed and extractedindependently by 2 reviewers. We evaluated the quality of theincluded studies using the Handbook 5.0 recommend standardsand then analyzed data by Cochrane Collaboration's RevMan 5.0.RESULTS Two trials which included a total of 348 patients wereanalyzed. The results of meta-analysis showed that gemcitabineimproved disease control rates significantly better than pegylatedliposomal doxorubicin. A greater number of patients receivinggemcitabine experienced neutropenia compared with patientsreceiving pegylated liposomal doxorubicin; however, hand-footsyndrome and mucositis were more severe in patients receivingpegylated liposomal doxorubicin.CONCLUSION Gemcitabine provided a limited advantagecompared with pegylated liposomal doxorubicin. There existsan urgent need for more high-quality, multicenter, adequaterandomized, controlled clinical trials for comparing gemcitabinewith pegylated liposomal doxorubicin in patients withprogressive/recurrent ovarian cancer.

Cost of treating chronic hepatitis B:Comparison of current treatment guidelines

AIM:To compare program costs of chronic hepatitis B(CHB) screening and treatment using Australian and other published CHB treatment guidelines.METHODS:Economic modeling demonstrated that in Australia a strategy of hepatocellular cancer(HCC) prevention in patients with CHB is more cost-effective than current standard care,or HCC screening.Based upon this model,we developed the B positive program to optimize CHB management of Australians born in countries of high CHB prevalence.We estimated CHB program costs using the B positive program algorithm and compared them to estimated costs of using the CHB treatment guidelines published by the AsianPacific,American and European Associations for the Study of Liver Disease(APASL,AASLD,EASL) and those suggested by an independent United States hepatology panel.We used a Markov model that factored in the costs of CHB screening and treatment,individualized by viral load and alanine aminotransferase levels,and calculated the relative costs of program components.Costs were discounted by 5% and calculated in Australian dollars(AUD).RESULTS:Using the B positive algorithm,total program costs amount to 13 979 224 AUD,or 9634 AUD per patient.The least costly strategy is based upon using the AASLD guidelines,which would cost 34% less than our B positive algorithm.Using the EASL and the United States Expert Group guidelines would increase program costs by 46%.The largest expenditure relates to the cost of drug treatment(66.9% of total program costs).The contribution of CHB surveillance(20.2%) and HCC screening and surveillance(6.6%) is small-and together they represent only approximately a quarter of the total program costs.CONCLUSION:The significant cost variations in CHB screening and treatment using different guidelines are relevant for clinicians and policy makers involved in designing population-based disease control programs.

Curing the fundamental issue of impurity phases in two-step solution-processed CsPbBr3 perovskite films

Inorganic lead halide perovskite CsPbBr3 offers attractive photophysical properties and phase stability for high-performance optoelectronic devices.However,CsPbBr3 films produced by the classic solution-based two-step method are always accompanied with impurity phases of CsPb2Br5 and Cs4PbBr6,which represents a major efficiency-limiting factor for future advances of CsPbBr3-based devices.The challenge lies in the complexity of the Cs-Pb-Br phase system,requiring both spatially and temporally precise control of the precursor stoichiometry during solution-phase growth of CsPbBr3 films.By adopting 2-methoxyethanol as the solution conversion medium instead of commonly applied methanol,the reaction between CsBr and PbBr2 can be finely controlled to yield single phase CsPbBr3 films within a few minutes;extending the solution-conversion step to 24 h does not alter the phase purity of resulting CsPbBr3 films.The present work paves the way to regulate the crystal growth behaviors of two-step solution-processed CsPbBr3 films by simple solvent engineering.

Hybrid UV photodetector with high photo-to-dark current ratio based on ordered TiO_2 nanorod arrays and polystyrene sulfate

Vertically aligned TiO2nanorods arrays were successfully synthesized on FTO glass by wet-chemical method.Based on polystyrene sulfate(PSS)functionalized TiO2nanorods arrays,a sandwich-structured hybrid UV photodetector was fabricated.The photo-to-dark current ratio of the device increases by more than 3 orders of magnitude with typical case,while the dark current is about 10 nA at 1 V bias.The high photoresponse together with the low dark current could probably contribute a large photocurrent and low-power application.The high performance of the hybrid material and facile low-cost fabrication of the UV detector make the devices promising for large-area UV photodetection applications.