Design and manufacture of emulsion liquid membrane based on various amine extractants for separation and extraction of succinic acid from fermentation broth

The aim of this study was to design a new emulsion liquid membrane(ELM)system for the separation of succinic acid from aqueous solutions.The concentration of succinic acid varied from 20 to 60 mmol·L^(-1).The prepared ELM system includes tributylamine(TBA)as a carrier,commercial kerosene as a solvent,Span 80 as a surfactant,and Na2CO3as a stripping agent.In order to control the membrane swelling,different values of cyclohexanone were added to the membrane phase.The effect of various empirical variables on the extraction of the succinic acid such as acid concentration in the feed solution,initial feed concentration,carrier concentration,the stirring speed of the extraction,Na2CO3,surfactant,and cyclohexanone concentrations,and treat ratio in the ELM system.The best result was obtained when TBA was used as the carrier.The final acid extraction efficiency was independent of pH variations of the aqueous feed solution.The extraction of succinic acid solution with a concentration of 40 mmol·L^(-1)was improved by increasing the treat ratio 1:7-1:3,stripping phase concentration 0.5-1.5 mol·L^(-1),stirring speed 300-500 r·min^(-1)and cyclohexanone concentration in the membrane phase 1.2-1.6 mol·L^(-1).No considerable effect on the extraction rate was observed for the carrier concentration in the membrane phase.But,the surfactant concentration in the feed phase showed a dual effect on the extraction efficiency.

Highly improved cyclic stability of Ni-rich/Li batteries with succinic anhydride as electrolyte additive and underlying mechanism

Lithium-metal battery based on Ni-rich cathode provides high energy density but presents poor cyclic stability due to the unstable electrode/electrolyte interfaces on both cathode and anode.In this work,we report a new strategy to address this issue.It is found that the cyclic stability of Ni-rich/Li battery can be significantly improved by using succinic anhydride(SA) as an electrolyte additive.Specifically,the capacity retention of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/Li cell is improved from 14% to 83% after 200cycles at 1 C between 3.0 and 4.35 V by applying 5% SA.The underlying mechanism of SA contribution is understood by comparing the effects of malic anhydride(MA) and citraconic anhydride(CA), both of which share a similar molecular structure to SA but show different effects.On anode side,SA can but MA and CA cannot form a protective solid electrolyte interphase(SEI) on Li anode.On cathode side,three anhydrides can suppress the formation of hydrogen fluoride from electrolyte oxidation decomposition,but SA behaves best.Typically,MA shows adverse effects on the interface stability of Li anode and NCM811 cathode,which originates from its high acidity.Though the acidity of MA can be mitigated by substituting a methyl for one H atom at its C=C bond,the substituent CA cannot compete with SA in cyclic stability improvement of the cell,because the SEI resulting from CA is not as robust as that from SA,which is related to the binding energy of the SEI components.This understanding reveals the importance of the electrolyte acidity on the Ni-rich cathode and the robustness of the SEI on Li anode,which is helpful for rationally designing new electrolyte additives to further improve the cyclic stability of high-energydensity Ni-rich/Li batteries.

Prevotella and succinate treatments altered gut microbiota,increased laying performance,and suppressed hepatic lipid accumulation in laying hens

Background This work aimed to investigate the potential benefits of administering Prevotella and its primary metabolite succinate on performance,hepatic lipid accumulation and gut microbiota in laying hens.Results One hundred and fifty 58-week-old Hyline Brown laying hens,with laying rate below 80%and plasma triglyceride(TG)exceeding 5 mmol/L,were used in this study.The hens were randomly allocated into 5 groups and subjected to one of the following treatments:fed with a basal diet(negative control,NC),oral gavage of 3 mL/hen saline every other day(positive control,PC),gavage of 3 mL/hen Prevotella melaninogenica(10^(7)CFU/mL,PM)or 3 mL/hen Prevotella copri(10^(7)CFU/mL,P.copri)every other day,and basal diet supplemented with 0.25%sodium succinate(Succinate).The results showed that PM and P.copri treatments significantly improved laying rate compared to the PC(P<0.05).The amount of lipid droplet was notably decreased by PM,P.copri,and Succinate treatments at week 4 and decreased by P.copri at week 8(P<0.05).Correspondingly,the plasma TG level in Succinate group was lower than that of PC(P<0.05).Hepatic TG content,however,was not significantly influenced at week 4 and 8(P>0.05).PM treatment increased(P<0.05)the mRNA levels of genes PGC-1βand APB-5B at week 4,and ACC and CPT-1 at week 8.The results indicated enhanced antioxidant activities at week 8,as evidenced by reduced hepatic malondialdehyde(MDA)level and improved antioxidant enzymes activities in PM and Succinate groups(P<0.05).Supplementing with Prevotella or succinate can alter the cecal microbiota.Specifically,the abundance of Prevotella in the Succinate group was significantly higher than that in the other 4 groups at the family and genus levels(P<0.05).Conclusions Oral intake of Prevotella and dietary supplementation of succinate can ameliorate lipid metabolism of laying hens.The beneficial effect of Prevotella is consistent across different species.The finding highlights that succinate,the primary metabolite of Prevotella,represents a more feasible feed additive for alleviating fatty liver in laying hens.

Therapeutic efficacy of methylprednisolone sodium succinate via diverse administration routes for mid-to high-frequency sudden sensorineural hearing loss

BACKGROUND Sudden sensorineural hearing loss(SSNHL),characterized by a rapid and unexplained loss of hearing,particularly at moderate to high frequencies,presents a significant clinical challenge.The therapeutic use of methylprednisolone sodium succinate(MPSS)via different administration routes,in combination with conventional medications,remains a topic of interest.AIM To compare the therapeutic efficacy of MPSS administered via different routes in combination with conventional drugs for the treatment of mid-to high-frequency SSNHL.METHODS The medical records of 109 patients with mid-to high-frequency SSNHL were analyzed.The patients were divided into three groups based on the route of administration:Group A[intratympanic(IT)injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection],Group B(intravenous injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection),and Group C(single IT injection of MPSS).The intervention effects were compared and analyzed.RESULTS The posttreatment auditory thresholds in Group A(21.23±3.34)were significantly lower than those in Groups B(28.52±3.36)and C(30.23±4.21;P<0.05).Group A also exhibited a significantly greater speech recognition rate(92.23±5.34)than Groups B and C.The disappearance time of tinnitus,time to hearing recovery,and disappearance time of vertigo in Group A were significantly shorter than those in Groups B and C(P<0.05).The total effective rate in Group A(97.56%)was significantly greater than that in Groups B and C(77.14%and 78.79%,χ^(2)=7.898,P=0.019).Moreover,the incidence of adverse reactions in Groups A and C was significantly lower than that in Group B(4.88%,3.03%vs 2.57%,χ^(2)=11.443,P=0.003),and the recurrence rate in Group A was significantly lower than that in Groups B and C(2.44%vs 20.00%vs 21.21%,χ^(2)=7.120,P=0.028).CONCLUSION IT injection of MPSS combined with conventional treatment demonstrates superior efficacy and safety compared to systemic administration via intravenous infusion and a single IT injection of MPSS.This approach effectively improves patients'hearing and reduces the risk of disease recurrence.

Anaerobiospirillum succiniciproducens厌氧发酵产琥珀酸的培养基优化研究

采用Plackett-Burman设计法,对影响Anaerobiospirillum succiniciproducens产琥珀酸的11个因素进行了筛选。结果表明,影响该菌厌氧发酵产琥珀酸的培养基的主要成分为葡萄糖、酵母抽提物和MgCO3。在此基础上,采用响应面法对其中3个显著因子的最佳水平范围进行研究。通过对二次多项回归方程求解得知,葡萄糖、酵母抽提物和MgCO3的质量浓度分别为39.17、14.68 g/L和25.76 g/L时,琥珀酸的产量从10.87 g/L提高到22.31 g/L。

Exogenous application of succinic acid enhances tolerance of Larix olgensis seedling to lead stress

Larix olgensis A. Henry(Changbai larch) is a productive commercial species and good candidate for afforestation in northeast China. It is widely planted in lead-stressed soils which can induce oxidative damage in this plant. Increasing tolerance to lead(Pb) stress is therefore of keen interest. A greenhouse experiment was conducted to identify the biomass, physiological responses and Pb accumulation of L. olgensis seedlings to Pb stress under succinic acid(SA) application and to explore the interaction of exogenous SA applications and stress resistance. L. olgensis seedlings were planted in Pb-stressed or unstressed haplic cambisols in pots. In Pb-contaminated soils the seedlings were treated daily with concentrations of SA solutions at a rate approximately equivalent to 0, 0.04,0.2, 1.0, or 2.0 mmol kg-1of soil for 10, 20, and 30 days,respectively. Pb treatment induced damage in the seedlings and led to the inhibition of biomass accumulation in roots,stems and leaves, and a rise in Pb accumulation in fine roots and leaves. Malondialdehyde(MDA) content and electrolyte leakage in leaves significantly increased while peroxidase(POD) activities, soluble protein and photosynthetic pigment contents in leaves were all reduced.Physiological toxicity was promoted with increasing Pb treatment times. When Pb-stressed seedlings were exposed to SA(especially 10.0 mmol L-1 over 20 days), the physiological responses for Pb-only were reversed and the biomass of roots, stems, and leaves dramatically increased.SA facilitated Pb uptake in fine roots and leaves but more Pb accumulated in fine roots. The results demonstrate that exogenous SA alleviates Pb-induced oxidative injuries and improves the tolerance of L. olgensis seedlings to Pb stress.

RING OPENING COPOLYMERIZATION OF SUCCINIC ANHYDRIDE-ETHYLENE OXIDE BY Al(Ⅲ) ORGANOMETALLIC CATALYSTS

Ring opening copolymerization of succinic anhydride (SA) with ethylene oxide (EO)was successfully carried out by using a series of aluminum-based catalyst in 1,4-dioxane at62±2℃. The results showed that in-situ AlR_3-H_2O (R=ethyl, iso-butyl) catalysts gavehigher molecular weight (M_w～10~4), while Al(OR)_3 catalysts gave the higher alternatingcopolymer structure with slightly lower molecular weight. The in-situ AlR_3-H_2O systemshave been evaluated in more detail for the reaction which showed the optimum H_2O/Almolar ratio to be 0.5. The copolymers with different composition (F_(SA)/F_(EO)= 36/64to 45/55 mol/mol) were synthesized by using different monomer feed ratio. The melt-ing point (T_m), glass transition temperature (T_g) and enthalpy of fusion (ΔH_f) of thesecopolymers are depended on the copolymer composition and in the range of 87～102℃,-12～-18℃, and 37～66J/g, respectively. The second heating scan of DSC also in-dicated that the higher alternating copolymer was more easily recrystallized. The onsetdecomposition temperature was more than 300℃ under nitrogen and influenced by thecopolymer composition.

Equilibrium of Extraction of Succinic, Malic, Maleic and Fumaric Acids with Trioctylamine

Extraction equilibrium features of succinic acid,malic acid,maleic acid and fumaric acid were investigated systematically with trioctylamine (TOA) in chloroform,4-methyl-2-pentanone (MIBK) and 1-octanol.Fourier transform-infrared(FTIR) spectroscopic analysis of organic samples loaded with the acid show that amine forms 1:1 complex of ion-pair association with succinic acid,malic acid and maleic acid,and 1:1,2:1 complex of ion-pair association with fumaric acid.It is proposed that the complex forms depend on the second dissociation constant of the dibasic acid,pKa2.Results of equilibrium experiments show that diluents affects extraction behavior,and depend on the solute concentration.Protic diluents,chloroform and 1-octanol,are more effective than the others when the equilibrium solute concentration.Protic diluents,chloroform and 1-octanol,are more effective tthan the others when the equilibrium solute concentration is lower than 1:1 stoichiometry of TOA to acid,otherwise the extraction ability shows that MIBK>1-octanol>chloroform for malic and maleic acids,and 1-octanol>MIBK>chloroform for succinic acid.Overloading(Solute concentration in organic phase is lager than TOA concentration) appears for all of the studied acids, and the sequence of overloading amount is the same as that of distribution constant of diluent.The results show that the sequence of extraction ability of different acid is the same as that of acidity at low equilibrium solute concentrations,while it is the same as the sequence of hydrophobicity at high equilibrium concentrations.

Nanoparticle-stabilized Alkenyl Succinic Anhydride(ASA)Emulsions:A Review

Alkenyl succinic anhydride(ASA) is a popular paper-sizing agent that is generally added to papermaking systems as an aqueous emulsion. Herein, we reviewed the recent work focusing on ASA emulsions stabilized by solid particles. Solid particle-stabilized ASA emulsions generally possess high ASA content and exhibit good sizing performance. The particles that have been used to stabilize ASA emulsions typically include montmorillonite, laponite, alumina, TiO_2, Fe_3O_4, polyaluminum sulfate(PAS), and cellulose nanocrystals(CNCs). Montmorillonite is the first extensively studied particle stabilizer for ASA emulsions. Laponite is undoubtedly the most competent particle stabilizer for preparing ASA emulsions with high sizing efficiency. Montmorillonite and laponite can be used individually as stabilizers after modification or as co-stabilizers with other particles or polymers. TiO_2, alumina, PAS, and CNCs are commonly used as stabilizers either individually or with other particles.

Selective Hydrogenation of Maleic Anhydride to Succinic Anhydride over Nickel Catalyst Supported on Carbon Microspheres

The colloidal carbon microspheres(CMS)were prepared by the hydrothermal method.The nickel catalysts supported on carbon microspheres(Ni/CMS)were further prepared and were characterized by the Fourier transform infrared spectroscopy(FTIR),the X-ray diffraction(XRD),the scanning electron microscopy(SEM),the transmission electron microscopy(TEM),and the N_(2)adsorption technique.The selective hydrogenation of maleic anhydride(MA)to succinic anhydride(SA)over the Ni/CMS catalysts was investigated.The results indicated that the Ni/CMS catalyst,which was prepared with glucose as carbon source and calcined at 500℃,exhibited the best performance.The hydrogen pressure,reaction temperature,and reaction time could significantly affect the conversion of maleic anhydride during the hydrogenation reaction.A 98.4%conversion of MA and an 100%selectivity to SA were achieved over the Ni/CMS catalyst in acetic anhydride solvent under mild conditions covering a temperature of 90℃,a H2 pressure of 1.0 MPa,and a reaction time of 3 h.

Ni-loaded Catalyst Containing Activated Clay for Maleic Anhydride Hydrogenation to Succinic Anhydride

In this work, the hydrogenation of maleic anhydride to succinic anhydride in the presence of 5 m%Ni/clay cata- lysts was investigated. These catalysts were characterized by X-ray diffraction (XRD), H2 temperature programmed reduc- tion (TPR) and thermogravimetric analysis (TGA) techniques. The XRD and TPR studies showed that Ni was present as Ni2+ on the support, which indicated that there were no elemental nickel (Ni0) and Ni2O3 species in the unreduced samples. Increasing of calcination temperature to 650 ℃ leads to destruction of the support structure observed in TGA, while the cat- alyst sample calcined at 550 ℃ exhibits better performances than other samples. The ideal conversion of maleic anhydride (97.14%) and selectivity of succinic anhydride (99.55%) were realized at a reaction temperature of 180 ℃ and a weight hourly space velocity of 4 h-1 under a reaction pressure of 1 MPa.

Osmotic concentration of succinic acid by forward osmosis:Influence of feed solution pH and evaluation of seawater as draw solution

In this study, we investigated the essential role of feed solution pH so as to gain insights into the transport mechanisms of succinic acid concentration by osmotically-driven forward osmosis(FO) process. FO performances including water flux and bidirectional transport of succinate and chloride anions were systematically examined using cellulose triacetate-based FO membrane. Additionally, real seawater was explored as draw solution. Experimental results revealed that the p H-dependent speciation of succinic acid can affect the FO performances. Ionization of succinic acid at higher solution p H enhanced the osmotic pressure of feed solution, thus leading to lower water flux performance. A strong effect was pointed out on the succinate rejection for which nearly 100% rejections were achieved at p H above its pK_(a2) value. The rejection of succinate increased in the following order of chemical form: C_2H_4 C_2O_4H_2 < C_2H_4C_2O_4H~ˉ < C_2H_4C_2O_4^(2-).With real seawater as the draw solution, low to moderate water fluxes(<4 L·m^(-2)·h^(-1)) were observed.The divalent succinate anion was highly retained in the feed side despite differences in the succinic acid feed concentration at p H of approximately 6.90.

Succinic Acid Production across Candidate Lignocellulosic Biorefinery Feedstocks

Non-food lignocellulosic crops with both high biomass yields and superior adaptation to marginal lands have significant potential as biofuel feedstocks that can replace fossil fuels. Deployment of dedicated crops into single biofuels, however, has been reduced by conversion technology costs and low petroleum prices. Integrated biorefinery strategies, in which value-added coproducts are generated in conjunction with biofuels, by comparison offer opportunities to overcome this economic disadvantage. The objective of this research was to evaluate succinic acid accumulation across candidate lignocellulosic feedstocks. Feedstock entries included pearl millet x napiergrass hybrids (“PMN”;Pennisetum glaucum [L.] R. Br. × P. purpureum Schumach.), napiergrass (P. purpureum Schumach.), annual sorghum (Sorghum bicolor [L.] Moench), pearl millet (P. glaucum [L.] R. Br.), perennial sorghum (Sorghum spp.), switchgrass (Panicum virgatum L.), sunn hemp (Crotalaria juncea L.), giant miscanthus (Miscanthus × giganteus J. M. Greef & Deuter) and energy cane (Saccharum spp. L.). Replicated field plots, as well as an independent greenhouse trial, were characterized for succinic acid content. The PMN, napiergrass, sunn hemp and energy cane entries had greater (P ≤ 0.05) succinic acid yields, up to 556 kg·ha-1, in field trials. Napiergrass and PMN entries similarly had higher succinic acid yields under greenhouse conditions;however, irrigation treatments did not alter succinic acid accumulation in this study. Napiergrass, PMN, and energy cane thus are promising biorefinery feedstocks.

Ischemic accumulation of succinate induces Cdc42 succinylation and inhibits neural stem cell proliferation after cerebral ischemia/reperfusion

Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In this study, we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery. We found that succinate levels increased in serum and brain tissue(cortex and hippocampus) after ischemia/reperfusion injury. Oxygen-glucose deprivation and reoxygenation stimulated primary neural stem cells to produce abundant succinate. Succinate can be converted into diethyl succinate in cells. Exogenous diethyl succinate inhibited the proliferation of mouse-derived C17.2 neural stem cells and increased the infarct volume in the rat model of cerebral ischemia/reperfusion injury. Exogenous diethyl succinate also increased the succinylation of the Rho family GTPase Cdc42 but repressed Cdc42 GTPase activity in C17.2 cells. Increasing Cdc42 succinylation by knockdown of the desuccinylase Sirt5 also inhibited Cdc42 GTPase activity in C17.2 cells. Our findings suggest that ischemic accumulation of succinate decreases Cdc42 GTPase activity by induction of Cdc42 succinylation, which inhibits the proliferation of neural stem cells and aggravates cerebral ischemia/reperfusion injury.

EFFECTSOFVASOACTIVEINTESTINALPEPTIDEONACTIVITIESOFSUCCINICDEHYDROGENASEANDALKALINEPHOSPHATASEINRATHEPATOMACELLS

Using cytochemical method,microspectrophotometry and image analysis,effects of va-soactive intestinal peptide(VIP)on activities of succinic dehydrogenase(SDH)and alkalinephosphatase(ALP)in rat hepatoma cells were studied in vitro.The results showed that thehepatoma cell expressed potent positive reactions of SDH and ALP,the positive positionswere located at the cell membranes and/or cytoplasm.Having been treated with VIP,ALPdecreased obviously in activity(P【0. 01,compared with hepatoma cells untreated by VIP).The sites of ALP activty were chiefly located at the cell membranes,particularly at the cell-cell contacts.Cultured rat hepatoma cells had intensive SDH activity in their cytoplasm.Compared with untreated eclls,there was no marked difference in the intensity of SDH activ-ity in VIP-treated hepatoma cells(P】0.05).

Enhanced Succinic Acid Production from Sake Lees Hydrolysate by Dilute Sulfuric Acid Pretreatment and Biotin Supplementation

Succinic acid is valued as a potential starting point for the production of chemicals of the C4 family or in the prepara-tion of biodegradable polymers. For sustainable development in this era of petroleum shortage, production of succinic acid by microbial fermentation of renewable feedstock has attracted great interest. In this study, pretreatment with sulfuric acid and biotin supplementation were used to enhance succinic acid production by Actinobacillus succinogenes 130Z from sake lees, a byproduct of Japanese rice wine. Pretreatment with sulfuric acid resulted in little change of glucose, total nitrogen and succinic acid content in the sake lees hydrolysate but had a positive effect on succinic acid fermentation, which caused a 25.0% increase in succinic acid yield in batch fermentation. Biotin supplementation was used to further enhance the fermentability of sake lees hydrolysate. As a result, a 30 h batch fermentation of 0.5% sulfuric acid pretreated sake lees hydrolysate with 0.2 mg/L biotin gave a succinic acid yield of 0.59 g/g from 61.6 g/L of glucose, with a productivity of 1.21 g/(L?h). A 22.9% increase in succinic acid yield and a 101.7% increase in succinic acid productivity were obtained compared with untreated sake lees hydrolysate.

Influence of ganglioside combined with methylprednisolone sodium succinate on efficacy and neurological function in patients with acute myelitis

BACKGROUND Acute myelitis(AM)can lead to sudden sensory,motor and autonomic nervous dysfunction,which negatively affects their daily activities and quality of life,so it is necessary to explore optimization from a therapeutic perspective to curb the progression of the disease.AIM To investigate the effect of ganglioside(GM)combined with methylprednisolone sodium succinate(MPSS)on the curative effect and neurological function of patients with AM.METHODS First,we selected 108 AM patients visited between September 2019 and September 2022 and grouped them based on treatment modality,with 52 patients receiving gamma globulin(GG)+MPSS and 56 patients receiving GM+MPSS,assigned to the control group(Con)and observation group(Obs),respectively.The therapeutic effect,neurological function(sensory and motor function scores),adverse events(AEs),recovery(time to sphincter function recovery,time to limb muscle strength recovery above grade 2,and time to ambulation),inflammatory factors(IFs)[interleukin(IL)-6,C-reactive protein(CRP),and tumor necrosis factor(TNF)-α]and other data of the two groups were collected for evaluation and comparison.RESULTS The Obs had:(1)A significantly higher response rate of treatment than the Con;(2)Higher scores of sensory and motor functions after treatment that were higher than the baseline(before treatment)and higher than the Con levels;(3)Lower incidence rates of skin rash,gastrointestinal discomfort,dyslipidemia,osteoporosis and other AEs;(4)Faster posttreatment recovery of sphincter function,limb muscle strength and ambulation;and(5)Markedly lower posttreatment IL-6,CRP and TNF-αlevels than the baseline and the Con levels.CONCLUSION From the above,it can be seen that GM+MPSS is highly effective in treating AM,with a favorable safety profile comparable to that of GG+MPSS.It can significantly improve patients’neurological function,speed up their recovery and inhibit serum IFs.

The Application of Cellulose Nanocrystals Modified with Succinic Anhydride under the Microwave Irradiation for Preparation of Polylactic Acid Nanocomposites

The aim of this work was to use cellulose nanocrystals that were obtained by hydrolysis in phosphoric acid solution and further modified with succinic anhydride in the microwave field for PLA reinforcement.A series of allbionanocomposites containing unmodified and surface modified cellulose nanocrystals with CNC content in the range of 1–3%_(w.t.) were obtained by melt blending and tested by XRD,SEM,DSC and DMA to investigate the effect of surface esterification of CNCs on the structure,morphology,dynamic mechanical properties of bionanocomposites,as well as phase transitions of PLA in the presence of cellulosic nanofiller.DMA investigations showed the highest increase of storage modulus by ca.7%(335 MPa at 25℃)in the glassy state of PLA for 2%_(w.t.)of unmodified CNC.Though,addition of 2%_(w.t.)of succinylated CNCs caused the highest increase of the onset of glass transition temperature(by 6.2℃)thus widening the temperature range of biocomposite application.The increase of glass transition temperature indicates the strongest interfacial interactions due to improved miscibility of surface modified nanocrystals and thus good dispersion of additive in PLA matrix providing high interface.

Clinical Efficacy of Metoprolol Succinic Acid Sustained Release Tablets Combined with Trimetazidine in the Treatment of Gastrointestinal Tumors with Angina Pectoris

Objective:To investigate the clinical efficacy of metoprolol succinate sustained-release tablets combined with trimetazidine in the treatment of gastrointestinal tumors with angina pectoris.Methods:We enrolled the 58 patients with digestive tract tumor merger angina in November 2017-October 2019 and analysis the hospital clinical data by retrospective method.We included patients with routine treatment in control group(n=31 cases)and the subjects treated with increased dose of succinic acid metoprololzyban joint with trimetazidineinobservation group(n=27 cases)according to the different treatment group.Results:The effective rate of angina pectoris treatment in the observation group was higher than that in the control group.Furthermore,the incidence of adverse reactions was lower than that in the control group and the difference was statistically significant(P<0.05).Conclusion:Metoprolol succinic acid sustained release tablets combined with trimetazidine in the treatment of gastrointestinal tumors with angina pectoris can improve the efficacy of angina pectoris.The drug use is safe and worthy of clinical use.

Insight into the green route to dimethyl succinate by direct esterification of bio-based disodium succinate using CO_(2)and CH_(3)OH

The fermentation for succinic acid production outperforms other methods by low energy consumption and environmental benignity,with the resulting products mainly as disodium succinate(DSA).By directly esterifying DSA using CO_(2) and CH3OH,it is expected to avoid the use of inorganic acids.By high-resolution mass spectrometry analysis and theoretical calculation,this study establishes that the reaction consists of three steps,i.e.,first forming 3-carboxypropanoate,then monomethyl succinate(MMS),and finally dimethyl succinate(DMS).A detailed kinetic analysis is further performed,the results demonstrate that the transformation of DSA to MMS is regarded to be a second-order reaction for reactant DSA,while the transformation of MMS to DMS is a first-order reaction for reactant MMS.The activation energy for the generation of MMS from DSA is 37.15 kJ·mol^(-1),and that for the generation of DMS from MMS is 85.80 kJ·mol^(-1),indicating the latter one is the rate-determining step.