D2EHPA萃取法从钒页岩高氯浸出液中制备钒电解液

提出一种从钒页岩中回收有价元素并制备钒电解液的工艺。结果表明,在料液pH值为2.6、萃取剂D2EHPA浓度为20%、相比(O/A)为1:1、萃取时间为8 min、H2SO4浓度为4 mol/L及反萃时间为30 min的条件下,钒萃取率为99.3%,反萃率为99.8%。对制备的电解液组成及电化学性能进行详细研究。溶液化学和红外光谱分析表明,浸出液中氯离子可以与钒离子络合,促进钒的萃取。采用本研究提出的工艺能实现钒页岩的综合利用,并避免钒电解液制备过程中有害物质对环境的潜在污染。

Ambipolar Doping of Monolayer FeSe by Interface Engineering

We report on ambipolar modulation doping of monolayer FeSe epitaxial films grown by molecular beam epitaxy and in situ spectroscopic measurements via a cryogenic scanning tunneling microscopy.It is found that hole doping kills superconductivity in monolayer FeSe films on metallic Ir(001)substrates,whereas electron doping from polycrystalline IrO_(2)/SrTiO_(3)substrate enhances significantly the superconductivity with an energy gap of 10.3 meV.By exploring substrate-dependent superconductivity,we elucidate the essential impact of substrate work functions on the superconductivity of monolayer FeSe films.Our results therefore offer a valuable reference guide for further enhancement of the transition temperature Tc in FeSe-based superconductors by interface engineering.

液相氢还原制备V2O3的φ-pH图和动力学研究

为了克服V_(2)O_(3)传统还原焙烧工艺具有的流程长、能耗高、污染大的缺点,采用液相氢还原(Sp HR)方法制备V_(2)O_(3),并对V-H_(2)O体系的φ-pH图和沉钒动力学进行分析。V-H_(2)O系φ-pH图的热力学分析表明:在酸性溶液中,通过液相氢还原制备V_(2)O_(3)需要较高的温度和钒浓度,以及充足的氢气。动力学研究表明:SpHR法制备V_(2)O_(3)的活化能为38.0679 k J/mol,表明该过程受界面化学反应和内扩散的混合步骤控制;氢分压(斜率k=0.05246)对反应速率的影响不如钒浓度(K=1.58872)显著。在pH=5~6、c(V_(2)O_(3))=0.5 mol/L、p(H;)=4 MPa、m(PdCl;)=10 mg、T=250℃及t=2.5 h的条件下,获得纯度为99.59%和沉钒率为99.83%的V_(2)O_(3)晶体。

De novo combined lamivudine and adefovir dipivoxil therapy vs entecavir monotherapy for hepatitis B virus-related decompensated cirrhosis

AIM:To compare efficacy of combined lamivudine(LAM)and adefovir dipivoxil(ADV)therapy with that of entecavir(ETV)monotherapy for hepatitis B virus(HBV)-related decompensated liver cirrhosis.METHODS:A total of 120 na ve patients with HBVrelated decompensated cirrhosis participated in this study.Sixty patients were treated with combined LAM and ADV therapy(LAM+ADV group),while the other60 were treated with ETV monotherapy(ETV group)for two years.Tests for liver and kidney function,alpha-fetoprotein,HBV serum markers,HBV DNA load,prothrombin time(PT),and ultrasonography or computed tomography scan of the liver were performed every1 to 3 mo.Repeated measure ANOVA and theχ2test were performed to compare the efficacy,side effects,and the cumulative survival rates at 48 and 96 wk.RESULTS:Forty-five patients in each group were observed for 96 wk.No significant differences in HBV DNA negative rates and alanine aminotransferase(ALT)normalization rates at weeks 48(χ2=2.12 and 2.88)and96(χ2=3.21 and 3.24)between the two groups were observed.Hepatitis B e antigen seroconversion rate in the LAM+ADV group at week 96 was significantly higher in the ETV group(43.5%vs 36.4%,χ2=4.09,P<0.05).Viral breakthrough occurred in 2 cases(4.4%)by week 48 and in 3 cases(6.7%)by week 96 in the LAM+ADV group,and no viral mutation was detected.In the ETV group,viral breakthrough occurred in 1 case(2.2%)at the end of week 96.An increase in albumin(F=18.9 and 17.3),decrease in total bilirubin and in ALT(F=16.5,17.1 and 23.7,24.8),reduced PT(F=22.7 and 24.5),and improved Child-Turcotte-Pugh and the model for end-stage liver disease scores(F=18.5,17.8,and 24.2,23.8)were observed in both groups.The cumulative rates of mortality and liver transplantation were 16.7%(10/60)and 18.3%(11/60)in the LAM+ADV and ETV groups,respectively.CONCLUSION:Both LAM+ADV combination therapy and ETV monotherapy can effectively inhibit HBV replication,improve liver function,and decrease mortality.

Early kidney injury during long-term adefovir dipivoxil therapy for chronic hepatitis B

AIM: To evaluate urine β2-microglobulin(β2-M), retinol-binding protein(RBP) excretion, and renal impairment with adefovir dipivoxil(ADV) for chronic hepatitis B. METHODS: We enrolled 165 patients with chronic hepatitis B infection who were treated with ADV monotherapy(n = 90) or ADV plus lamivudine combination therapy(n = 75). An additional 165 chronic hepatitis B patients treated with entecavir were recruited as controls. We detected serum creatinine, urine β2-M, and RBP levels, and estimated the glomerular filtration rate(e GFR) at the initiation of antiviral therapy and every 6 mo for a period of five years. RESULTS: Urine β2-M abnormalities were observed in patients during the first(n = 3), second(n = 7), third(n = 11), fourth(n = 16), and fifth(n = 21) year of ADV treatment. Urinary RBP abnormalities were observed in patients during the first(n = 2), second(n = 8), third(n = 12), fourth(n = 15), and fifth(n = 22) year of ADV treatment. e GFR decreased 20%-30% from baseline in 20 patients, 30%-50% in 12 patients, and > 50% in 3 patients during the five years of treatment. Further analysis indicated that decreases in e GFR of ≥ 30% relative to the baseline level correlated significantly with urine RBP and β2-M abnormalities. In contrast, both serum creatinine and e GFR remained stable in patients treated with entecavir, and only one of these patients developed a urine β2-M abnormality, and two developed urine RBP abnormalities during the five years of treatment. CONCLUSION: Urine RBP and β2-M are biomarkers of renal injury during long-term ADV treatment for chronic hepatitis B, and indicate when treatment should be switched to entecavir.

Mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes from stone coal

The mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes were researched by comparing the blank extraction with the extraction with calcium fluoride as aid-leaching reagent. The leaching experiments were carried out under the conditions of 95 ~C, 6 h, 1.5 ml.g-1, 15 vol % H2SO4, and 5 % calcium fluoride （mass ratio of CaF2 to stone coal）. The concentrations of hydrogen ion were adjusted from initial 1.82 and 4.79 mol.L-1 to the pH of 1.80 4- 0.05 by 200 g.L-1 lime milk, respectively. The solvent extraction experiments were carded out under the organic phase using 15 vol% D2EHPA, 5 vol% TBP, and 80 vol% sulfonated kerosene and O/A phase ratio of 1/4. The leaching rate of vanadium and six-stage countercurrent solvent extraction rate of vanadium can be remarkably improved from 66.71 to 92.97 % and 81.15 to 98.81%, respectively, when calcium fluoride was added as aid-leaching reagent. In the leaching process, fluorine can enhance the breakage of the structure of vanadium-bearing minerals. Meanwhile, fluoride ion can combine with iron ion to generate acid-insoluble iron fluoride hydrate （Fe2Fs.7H20） and consume all ferric ions and a portion of ferrous ions. In adjusting pH value process, the massive impurities are decreased to form KA1SO4 and FeA1Fs. In solvent extraction process, fluorine can prevent the formation of ferric hydroxide colloids and eliminate the formed unstable ferric hydroxide colloids and the silicon-containing colloids to promote the sufficient contact between the aqueous phase and the organic phase and the sufficient reaction.

Effects of the mineral phase and valence of vanadium on vanadium extraction from stone coal

The influence of roasting on the leaching rate and valence of vanadium was evaluated during vanadium extraction from stone coal. Vanadium in stone coal is hard to be leached and the leaching rate is less than 10% when the raw ore is leached by 4 moUL H2SO4 at 90℃ for 2 h. After the sample is roasted at 900℃ for 2 h, the leaching rate of vanadium reaches the maximum, and more than 70% of vanadium can be leached. The crystal of vanadium-bearing mica minerals decomposes and the Content of V（V） increases with the rise of roasting temperature from 600 to 900℃, therefore the leaching rate of vanadium increases significantly with the decomposition of the mica minerals. Some new phases, anorthite for example, form when the roasting temperature reaches 1000℃. A part of vanadium may be enwrapped in the sintered materials and newly formed phases, which may impede the oxidation of low valent vanadium and make the leaching rate of vanadium drop dramatically. The leaching rate of vanadium is not only determined by the valence state of vanadium but also controlled by the decomposition of vanadium-bearing minerals and the existence state of vanadium to a large extent.

A novel process for the recovery of iron,titanium,and vanadium from vanadium-bearing titanomagnetite:sodium modification–direct reduction coupled process

A sodium modification–direct reduction coupled process was proposed for the simultaneous extraction of V and Fe from vanadium- bearing titanomagnetite. The sodium oxidation of vanadium oxides to water-soluble sodium vanadate and the transformation of iron oxides to metallic iron were accomplished in a single-step high-temperature process. The increase in roasting temperature favors the reduction of iron oxides but disfavors the oxidation of vanadium oxides. The recoveries of vanadium, iron, and titanium reached 84.52%, 89.37%, and 95.59%, respectively. Moreover, the acid decomposition efficiency of titanium slag reached 96.45%. Compared with traditional processes, the novel process provides several advantages, including a shorter flow, a lower energy consumption, and a higher utilization efficiency of vanadium-bearing titanomagnetite resources. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

Hepatitis B surface antigen levels during natural history of chronic hepatitis B: A Chinese perspective study

AIM: To determine the baseline hepatitis B surface antigen(HBsAg) levels during the different phases of chronic hepatitis B(CHB) patients in China.METHODS: Six hundred and twenty-three hepatitis B virus or un-infected patients not receiving antiviral therapy were analyzed in a cross-sectional study. The CHB patients were classified into five phases: immunetolerant(IT, n = 108), immune-clearance(IC, n = 161), hepatitis B e antigen negative hepatitis(ENH, n = 149), low-replicative(LR, n = 135), and liver cirrhosis(LC, n = 70). HBsAg was quantified(Abbott ARCHITECT assay) and correlated with hepatitis B virus(HBV) DNA, and serum alanine aminotransferase/aspartate aminotransferase(ALT/AST) in each phase of CHB was also determined.RESULTS: Median HBsAg titers were different in each phase of CHB(P < 0.001): IT(4.85 log10 IU/mL), IC(4.36 log10 IU/mL), ENH(2.95 log10 IU/mL), LR(3.18 log10 IU/mL) and LC(2.69 log10 IU/mL). HBsAg titers were highest in the IT phase and lowest in the LC phase. Serum HBsAg titers showed a strong correlation with HBV viral load in the IC phase(r = 0.683, P < 0.001). No correlation between serum HBsAg level and ALT/AST was observed.CONCLUSION: The mean baseline HBsAg levels differ significantly during the five phases of CHB, providing evidence on the natural history of HBV infection. HBsAg quantification may predict the effects of immunemodulator or oral nucleos(t)ide analogue therapy.

Formation and thermodynamics of CaS-bearing inclusions during Ca treatment in oil casting steels

Industrial experiments were carried out to investigate the formation of CaS-bearing inclusion during Ca double modification in oil casting steels using polished cross sections and electrolytic extraction. Immediately after Ca addition, the role of newly generated CaS as an intermediate reaction product, which modified the Al_2O_3 inclusion into a liquid calcium aluminate, was confirmed. The formation of transient CaS was attributed to the high surface segregation of S at the liquid steel-calcium vapor interface, where a simple site coverage model based upon the Langmuir adsorption equation was established. Moreover, a CaS outer layer surrounding the liquid calcium aluminate was attained mainly in the tundish, which was distributed unevenly on the surface of liquid particles according to the three-dimensional mapping results. The surface of a well-modified calcium aluminate with higher CaO activity and Al_2O_3 activity under bulk composition conditions in the tundish acted as a favorable site for the generation of CaS. Additionally, CaS could be precipitated directly onto existing inclusions during solidification of the steel, which led to various morphologies of CaS-bearing inclusions in slabs. Furthermore, the phase transformation of inclusions during solidification was strongly influenced both by the S content and the Ca/S ratio in the tundish via thermodynamics.

Morphological and mineralogical characterizations of oolitic iron ore in the Exi region, China

The morphological and mineralogical characterizations of a Chinese oolitic iron ore （Exi deposit） were studied by scanning electron microscopy and energy-dispersive X-ray spectroscopy in this work. It is shown that the Exi ore is mainly composed of hematite, quartz, apatite, and chlorite. The hematite is present as the oolitic layers and in the spaces between the aggregated ooids; quartz exists as granular particles in the spaces and as nucleuses in ooids; the harmful mineral, apatite, is associated with hematite as the oolitic layers, fine dissemination, granular particles in the spaces, and nucleuses in ooids. From the viewpoint of mineral beneficiation, it is hard to separate apatite and chlorite but easy to separate quartz from hematite in the Exi iron ore in recovering the iron values.

High frequency of thrombocytopenia in patients with acute-on-chronic liver failure treated with linezolid

BACKGROUND： Linezolid is an effective antibiotic reagent for Gram-positive bacterial infection; its most common side effect is thrombocytopenia. However, the incidence of throm- bocytopenia in patients with acute-on-chronic liver failure （ACLF） who underwent linezolid therapy was unclear. The present study was to evaluate the incidence of thrombocyto- penia in ACLF and non-ACLF patients treated with linezolid and the risk factors of thrombocytopenia in these patients.

A Reliability Allocation Method of CNC Lathes Based on Copula Failure Correlation Model

The current research of reliability allocation of CNC lathes always treat CNC lathes as independent series systems. However, CNC lathes are complex systems in the actual situation. Failure correlation is rarely considered when reliabil?ity allocation is conducted. In this paper, drawbacks of reliability model based on failure independence assumption are illustrated, after which, reliability model of CNC lathes considering failure correlation of subsystems is established based on Copula theory, which is an improvement of traditional reliability model of series systems. As the failure time of CNC lathes often obeys Weibull or exponential distribution, Gumbel Copula is selected to build correlation model. After that, a reliability allocation method considering failure correlation is analyzed based on the model established before. Reliability goal is set first and then failure rates are allocated to subsystems according to the allocation vector through solving the correlation model. Reliability allocation is conducted for t = 1. A real case of a CNC lathe and a numerical case are presented together to illustrate the advantages of the reliability model established consider?ing failure correlation and the corresponding allocation method. It shows that the model accords to facts and real working condition more, and failure rates allocated to all the subsystems are increased to some extent. This research proposes a reliability allocation method which takes failure correlation among subsystems of CNC lathes into consid?eration, and costs for design and manufacture could be decreased.

Synergistic effect of microwave irradiation and CaF2 on vanadium leaching

The effect and mechanism of microwave irradiation on vanadium leaching were studied via a comparison between microwave heating and conventional heating. The results show a synergistic effect of microwave irradiation and calcium fluoride （CaF2） on the vana- dium leaching efficiency. It is confirmed that the vanadium leaching process can be improved by microwave irradiation when CaF2 is present. The leaching rate of vanadium under microwave irradiation is increased by 8%-15% when 5wt% CaF2 is added; by contrast, in the absence of CaF2, the leaching rate is almost unaffected compared to that by conventional heating. Morphological analysis reveals that the particles are gradually eroded by acid under microwave irradiation, whereas some of the fine particles in samples subjected to conventional heating are tightly covered by a flocculent silicate product. Moreover, a large amount of A1 and V and a small amount of Si are dissolved from samples under microwave heating, as revealed by the elemental analysis of leachates. Fourier transform infrared spectroscopic analysis also indicates a higher mass transfer coefficient in the diffusion layer of the raw material by microwave irradiation. When CaF2 is present, the reaction energy barrier is lowered and the leaching process is controlled by the tightly covered product layer, resulting in a prominent effect of mi- crowave irradiation.

Comparison of the mechanisms of microwave roasting and conventional roasting and of their effects on vanadium extraction from stone coal

Experiments comparing microwave blank roasting and conventional blank roasting for typical vanadium-bearing stone coal from Hubei Province in central China, in which vanadium is present in muscovite, were conducted to investigate the effects of roasting tempera- ture, roasting time, H2SO4 concentration, and leaching time on vanadium extraction. The results show that the vanadium leaching efficiency is 84% when the sample is roasted at 800℃ for 30 min by microwave irradiation and the H2SO4 concentration, liquid/solid ratio, leaching temperature, and leaching time are set as 20vo1%, 1.5：1 mL.g-1, 95℃, and 8 h, respectively. However, the vanadium leaching efficiency achieved for the sample subjected to conventional roasting at 900℃ for 60 min is just 71% under the same leaching conditions. Scanning electron microscopy （SEM） analysis shows that the microwave roasted samples contain more cracks and that the particles are more porous compared to the conventionally roasted samples. According to the results of X-ray diffraction （XRD） and Fourier-transform infrared （FTIR） analyses, neither of these roasting methods could completely destroy the mica lattice structure under the experimental conditions; however, both methods deformed the muscovite structure and facilitated the leaching process. Comparing with conventional roasting, microwave roasting causes a greater deformation of the mineral structure at a lower temperature for a shorter roasting time.

HBsAg levels in HBeAg-positive chronic hepatitis B patients with different immune conditions

AIM:To investigate hepatitis B surface antigen(HBsAg)levels in patients with HBeAg-positive chronic hepatitis B(CHB)and different immune conditions.METHODS:HBeAg-positive CHB patients with different immune conditions were enrolled in this cross-sectional study.These patients were grouped according to the following criteria:immune-tolerant patients,IT group;patients with a mild immune response in the immune clearance phase,IC-Mild group;and patients with a dramatic immune response in the immune clearance phase and exhibiting acute on chronic liver failure(ACLF),ACLF group.All these patients had not previously received antiviral therapy and were enrolled at a pre-settled ratio of2:2:1.Serum HBsAg levels and the correlation between serum HBsAg level and serum hepatitis B virus(HBV)DNA level were evaluated in these groups.RESULTS:In total,180 HBeAg-positive CHB patients[IT group(n=72),IC-Mild group(n=72),and ACLF group(n=36)]were enrolled in this study.The median serum HBsAg levels varied among the groups(P<0.001):IT,4.86 log10IU/mL;IC-Mild,3.97 log10IU/mL;and ACLF,3.57 log10IU/mL.Serum HBsAg level showed a moderate positive correlation with serum HBV-DNA level in the IC-Mild group(r=0.60,P<0.001),but exhibited a weaker correlation in the IT(r=0.52,P<0.001)and ACLF groups(r=0.51,P=0.001).The ratio of HBsAg/HBV DNA did not differ significantly among the IT,IC-Mild,and ACLF groups(medians:0.56,0.55,and 0.56,respectively;P=0.179).CONCLUSION:Serum HBsAg levels varied significantly in HBeAg-positive patients with different immune conditions.These findings may have important implications for understanding the immune clearance of HBV in HBeAg-positive CHB patients.

A method for recovery of iron,titanium,and vanadium from vanadium-bearing titanomagnetite

An innovative method for recovering valuable elements from vanadium-bearing titanomagnetite is proposed. This method involves two procedures： low-temperature roasting of vanadium-bearing titanomagnetite and water leaching of roasting slag. During the roasting process, the reduction of iron oxides to metallic iron, the sodium oxidation of vanadium oxides to water-soluble sodium vanadate, and the smelting separation of metallic iron and slag were accomplished simultaneously. Optimal roasting conditions for iron/slag separation were achieved with a mixture thickness of 42.5 mm, a roasting temperature of 1200°C, a residence time of 2 h, a molar ratio of C/O of 1.7, and a sodium carbonate addition of 70 wt%, as well as with the use of anthracite as a reductant. Under the optimal conditions, 93.67% iron from the raw ore was recovered in the form of iron nugget with 95.44% iron grade. After a water leaching process, 85.61% of the vanadium from the roasting slag was leached, confirming the sodium oxidation of most of the vanadium oxides to water-soluble sodium vanadate during the roasting process. The total recoveries of iron, vanadium, and titanium were 93.67%, 72.68%, and 99.72%, respectively.

Efficient generation of functional hepatocytelike cells from mouse liver progenitor cells via indirect co-culture with immortalized human hepatic stellate cells

BACKGROUND： Differentiation of liver progenitor cells（LPCs） to functional hepatocytes holds great potential to develop new strategies for hepatocyte transplantation and the screening of drug-induced cytotoxicity. However, reports on the efficient and convenient hepatic differentiation of LPCs to hepatocytes are few. The present study aims to investigate the possibility of generating functional hepatocytes from LPCs in an indirect co-culture system.METHODS： Mouse LPCs were co-cultured in Transwell plates with an immortalized human hepatic stellate cell line（HSCLi） we previously established. The morphology, expression of hepatic markers, and functions of mouse LPC-derived cells were monitored and compared with those of conventionally cultured LPCs. RESULTS： Co-culturing with HSC-Li cells induced differentiation of mouse LPCs into functional hepatocyte-like cells. The differentiated cells were morphologically transformed into hepatocyte-like cells 3 days after co-culture initiation. In addition, the differentiated cells expressed liver-specific genes and possessed hepatic functions, including glycogen storage, lowdensity lipoprotein uptake, albumin secretion, urea synthesis, and cytochrome P450 1A2 enzymatic activity.CONCLUSIONS： Our method, which employs indirect co-culture with HSC-Li cells, can efficiently induce the differentiation of LPCs into functional hepatocytes. This finding suggests that this co-culture system can be a useful method for the efficient generation of functional hepatocytes from LPCs.

Adsorption properties of Ⅴ(Ⅳ) on resin-activated carbon composite electrodes in capacitive deionization

Composite electrodes prepared by cation exchange resins and activated carbon(AC)were used to adsorb Ⅴ(Ⅳ)in capacitive deionization(CDI).The electrode made of middle resin size(D860/AC M)had the largest specific surface area and mesoporous content than two other composite electrodes.Electrochemical analysis showed that D860/AC M presents higher specific capacitance and electrical double layer capacitor than the others,and significantly lower internal diffusion impedance.Thus,D860/AC M exhibits the highest adsorption capacity and rate of Ⅴ(Ⅳ)among three electrodes.The intra-particle diffusion model fits well in the initial adsorption stage,while the liquid film diffusion model is more suitable for fitting at the later stage.The pseudo-second-order kinetic model is suited for the entire adsorption process.The adsorption of Ⅴ(Ⅳ)on the composite electrode follows that of the Freundlich isotherm.Thermodynamic analysis indicates that the adsorption of Ⅴ(Ⅳ)is an exothermic process with entropy reduction,and the electric field force plays a dominant role in the CDI process.This work aims to improve our understanding of the ion adsorption behaviors and mechanisms on the composite electrodes in CDI.

Immunoregulation of KangAi injection combined with chemotherapy in advanced non-small cell lung cancer: a systematic review and meta-analysis

Objective: To evaluate the immunoregulation of KangAi (KA) injection combined with chemo-treatment (chemo) for Non-small cell lung cancer (NSCLC). Methods: We systematically searched the literature of PubMed, EMBASE, CENTRAL, MEDLINE, CNKI, Wanfang, and VIP databases for all Randomized controlled trials (published from the earliest possible year to January 2019, no language restrictions) comparing KA injection combined with chemo and chemo alone in patients with NSCLC. Our main endpoints were immune function, clinical efficiency, KPS score and adverse events. The Cochrane Risk of Bias tool was applied for quality assessment. Results: 11 studies involving 1060 participants were included. The immune function (MD=3.18, 95% CI: 0.98-4.00, P<0.00001), clinical response rate (RR=1.28, 95%CI: 1.17-1.40, P<0.00001), KPS score (RR=1.86, 95%CI: 1.35-2.57, P=0.0002), and adverse events (RR=0.57, 95%CI: 0.50-0.65, P<0.00001) in the group of KA injection plus Chemo were vastly different from those in Chemo alone. Conclusion: KA injection combined with Chemo in the treatment of NSCLC improved the immune function, clinical efficiency and safety compared to Chemo alone. However, because many of the methodologies included in randomized controlled trials are of poor quality, more rigorous design and large randomized controlled trials are needed to test this benefit.