Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-...Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO_(2))that achieved 96.6%yield for the hydrogenation rearrangement of furfural to cyclopentanone at mild conditions(1 MPaH_(2),150°C).The turnover frequency of Ni-P/mSiO_(2)was 411.9 h^(-1),which was 3.2-fold than that of Ni/mSiO_(2)(127.2 h^(-1)).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were generated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density functional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.展开更多
Pd/Cu liquid-phase composite was utilized as the catalyst in this study to remove PH_(3) at low temperatures.The anti-heterotoxicity of catalysts in the PH_(3) catalytic oxidation purification process was carefully ex...Pd/Cu liquid-phase composite was utilized as the catalyst in this study to remove PH_(3) at low temperatures.The anti-heterotoxicity of catalysts in the PH_(3) catalytic oxidation purification process was carefully explored and pioneered.The catalytic performance,thermodynamics,kinetics,and catalytic oxidation mechanism of Pd/Cu liquid-phase catalyst catalytic oxidation of PH_(3) were thoroughly investigated.The results showed that Pd/Cu has a superior catalytic effect on the removal of PH_(3) in the gas mixture under low temperature.With CO as the carrier gas,the removal efficiency of PH_(3) could be maintained at 100%for nearly 450 min,indicating that the Pd/Cu liquid phase catalyst has good resistance to heterotoxicity.According to the thermodynamic,kinetic,and related characterization results of the PH_(3) purification process,the kinetic region of the gas–liquid reaction of PH_(3) absorption by Pd/Cu solution was an interfacial reaction.Pd was the primary catalyst and Cu was the secondary catalyst,and the adsorption of PH_(3)was a primary reaction.PH_(3) was spontaneously oxidized to H_(3)PO_(4) in the Pd/Cu catalytic system during the removal process.Pd was regenerated by O_(2) and Cu,increasing the activity and stability of the Pd/Cu catalyst in the sustain and efficient purification of PH_(3) in tail gas.展开更多
Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O...Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O-containing value-added chemicals thereby replacing the traditional petroleum-based approaches.The scope for developing efficient bifunctional catalysts and establishing mild reaction conditions for upgrading furfurals to cyclic compounds has stimulated immense deliberation in recent years.Extensive efforts have been made toward developing catalysts for multiple tandem conversions,including those with various metals and supports.In this scientific review,we aim to summarize the research progress on the synergistic effect of the metal-acid sites,including simple metal-supported acidic supports,adjacent metal acid sites-supported catalysts,and in situ H_(2)-modified bifunctional catalysts.Distinctively,the catalytic performance,catalytic mechanism,and future challenges for the hydrogenative rearrangement are elaborated in detail.The methods highlighted in this review promote the development of C_(5) cyclic compound synthesis and provide insights to regulate bifunctional catalysis for other applications.展开更多
Under mild conditions, conversion of a variety of ketoximes and aldoximes to their corresponding amides and nitriles proceeded in the presence of PEG-SO3H with high yields.
AIM:To study the diagnostic value of immunoglobulin heavy chain(IgH)and T-cell receptorγ (TCR-γ)gene monoclonal rearrangements in primary gastric lymphoma(PGL).METHODS:A total of 48 patients with suspected PGL at ou...AIM:To study the diagnostic value of immunoglobulin heavy chain(IgH)and T-cell receptorγ (TCR-γ)gene monoclonal rearrangements in primary gastric lymphoma(PGL).METHODS:A total of 48 patients with suspected PGL at our hospital were prospectively enrolled in this study from January 2009 to December 2011.The patients were divided into three groups(a PGL group,a gastric linitis plastica group,and a benign gastric ulcer group)based on the pathological results(gastric mucosal specimens obtained by endoscopy or surgery)and follow-up.Endoscopic ultrasonography(EUS)and EUSguided biopsy were performed in all the patients.The tissue specimens were used for histopathological examination and for IgH and TCR-γ gene rearrangement polymerase chain reaction analyses.RESULTS:EUS and EUS-guided biopsy were successfully performed in all 48 patients.In the PGL group(n=21),monoclonal IgH gene rearrangements were detected in 14(66.7%)patients.A positive result for each set of primers was found in 12(57.1%),8(38.1%),and 4(19.0%)cases using FR1/JH,FR2/JH,and FR3/JH primers,respectively.Overall,12(75%)patients with mucosal-associated lymphoid tissue lymphoma(n=16)and 2(40%)patients with diffuse large B-cell lymphoma(n=5)were positive for monoclonal IgH gene rearrangements.No patients in the gastric linitis plastica group(n=17)and only one(10%)patient in the benign gastric ulcer group(n=10)were positive for a monoclonal IgH gene rearrangement.No TCRgene monoclonal rearrangements were detected.The sensitivity of monoclonal IgH gene rearrangements was 66.7%for a PGL diagnosis,and the specificity was96.4%.In the PGL group,8(100%)patients with stage IIE PGL(n=8)and 6(46.1%)patients with stage IE PGL(n=13)were positive for monoclonal IgH gene rearrangements.CONCLUSION:IgH gene rearrangements may be associated with PGL staging and may be useful for the diagnosis of PGL and for differentiating between PGL and gastric linitis plastica.展开更多
Acquired immune deficiency syndrome (AIDS)-related lymphoma (ARL) remains the main cause of AIDS-related deaths in the highly active anti-retroviral therapy (HAART) era. Recently, rearrangement of MYC is associated wi...Acquired immune deficiency syndrome (AIDS)-related lymphoma (ARL) remains the main cause of AIDS-related deaths in the highly active anti-retroviral therapy (HAART) era. Recently, rearrangement of MYC is associated with poor prognosis in patients with diffuse large B-cell lymphoma. Here, we report a rare case of gastrointestinal (GI)-ARL with MYC rearrangements and coinfected with Epstein-Barr virus (EBV) infection presenting with various endoscopic findings. A 38-yearold homosexual man who presented with anemia and was diagnosed with an human immunodeficiency virus infection for the first time. GI endoscopy revealed multiple dish-like lesions, ulcerations, bloody spots, nodular masses with active bleeding in the stomach, erythematous flat lesions in the duodenum, and multiple nodular masses in the colon and rectum. Magnified endoscopy with narrow band imaging showed a honeycomb-like pattern without irregular microvessels in the dish-like lesions of the stomach. Biopsy specimens from the stomach, duodenum, colon, and rectum revealed diffuse large B-cell lymphoma concomitant with EBV infection that was detected by high tissue EBV-polymerase chain reaction levels and Epstein-Barr virus small RNAs in situ hybridization. Fluorescence in situ hybridization analysis revealed a fusion between the immunoglobulin heavy chain (IgH) and c-MYC genes, but not between the IgH and BCL2 loci. After 1-mo of treatment with HAART and R-CHOP, endoscopic appearance improved remarkably, and the histological features of the biopsy specimens revealed no evidence of lymphoma. However, he died from multiple organ failure on the 139 th day after diagnosis. The cause of his poor outcome may be related to MYC rearrangement. The GI tract involvement in ARL is rarely reported, and its endoscopic findings are various and may be different from those in non-AIDS GI lymphoma; thus, we also conducted a literature review of GI-ARL cases.展开更多
Caprolactam, which is mainly produced via the Beckmann rearrangement reaction, is an important chemical material. The strict specifications of caprolactam products make the refining process of caprolactam extremely im...Caprolactam, which is mainly produced via the Beckmann rearrangement reaction, is an important chemical material. The strict specifications of caprolactam products make the refining process of caprolactam extremely important. According to the different rearrangement process, the refining process of caprolactam is also different. The main refining sequence of liquid phase rearrangement products includes extraction, ion exchange, hydrogenation, and distillation. The refining process of gas phase rearrangement products is conducted mainly through distillation, crystallization, and hydrogenation. In this paper, the research progress of caprolactam refining technology will be summarized according to different rearrangement reaction processes, which will provide a reference for the selection of appropriate caprolactam refining process.展开更多
Six Brnsted acidic ionic liquids(ILs) 1a―1f were synthesized and used as the dual solvent-catalyst systems for Beckmann rearrangement reactions. Among ILs 1a―1f, IL 1a exhibited the highest catalytic activity and ...Six Brnsted acidic ionic liquids(ILs) 1a―1f were synthesized and used as the dual solvent-catalyst systems for Beckmann rearrangement reactions. Among ILs 1a―1f, IL 1a exhibited the highest catalytic activity and successfully catalyzed the Beckmann rearrangement of ketoximes, and the corresponding amides were obtained in good to excellent yields(74%―92%). In addition, IL 1a could be recovered easily and reused at least three times without any loss of catalytic activity.展开更多
The reaction mechanism of amadori rearrangement in the initial stage of Maillard reaction has been investigated by means of density functional theory calculations in the gaseous phase and aqueous solution.Cyclic ribos...The reaction mechanism of amadori rearrangement in the initial stage of Maillard reaction has been investigated by means of density functional theory calculations in the gaseous phase and aqueous solution.Cyclic ribose and glycine were taken as the model in the amadori rearrangement.Reaction mechanisms have been proposed,and possibility for the formation of different compounds has been evaluated through calculating the relative energy changes for different steps of the reaction by following the total mass balance.The calculations reveal that the amadori rearrangement initialized via the intramolecular rearrangement,transferring one proton from N(3) to O(4) atom.In the next step,the second proton is also transferred from N(3) to O(4) atom,corresponding to the cleavage of C(4)-O(4) bond and the release of one water molecule.Then another proton is transferred from N(3) to C(5) atom via TS3 with the reaction barrier of 58.3 kcal·mol-1 after tunneling the effect correction calculated at the B3LYP/6-31+G(d) level of theory,and this step is rate limiting for the whole catalytic cycle.Ultimately,the product is generated via keto-enolic tautomerization.Present calculation could provide insights into the reaction mechanism of Maillard reaction since experimental evaluation of the role of intermediates in the Maillard reaction is quite complicated.展开更多
The rearrangement of Bcl-1 gene (Bcl-1/IgH rearrangement) and expression of cyclin D1 in multiple myeloma (MM) precursor cells were studied and the role of cyclin D1 in the pathogenesis of MM was investigated. The BCL...The rearrangement of Bcl-1 gene (Bcl-1/IgH rearrangement) and expression of cyclin D1 in multiple myeloma (MM) precursor cells were studied and the role of cyclin D1 in the pathogenesis of MM was investigated. The BCL-1 rearrangement and cyclin D1 protein expression in 15 cases of MM were detected. By using hemi-nested polymerase chain reaction (PCR) the genomic DNA from fresh peripheral blood and bone marrow was amplified and the expression of cyclin D1 in the smears was detected by using immunohistochemical method. Ten volunteer with normal bone marrow served as control group. The results showed Bcl-1 rearrangement was detectable in 3/15 (20 %) MM patients and cyclin D, expression in 4/15 (27 % ) MM patients. BeLl-1 rearrangement and cyclin D1 protein expression were also detected in MM precursor cells. No overexpression of cyclin D1 or the rearrangement of the BeL-1 gene was found in the 10 volunteers. It was concluded that Bel-1 rearrangement and cyclin D1 protein overexpression were detected in MM precursor cells, speculating that overexpression of cyclin D1 protein may play an initial (critical) role in the pathogenesis of MM.展开更多
The kinetics of liquid-phase hydrogenation of toluene catalyzed by MlNi_5 was studied by investigating the influences of the reaction temperature and pressure on the mass transfer-reaction processes inside the slurry....The kinetics of liquid-phase hydrogenation of toluene catalyzed by MlNi_5 was studied by investigating the influences of the reaction temperature and pressure on the mass transfer-reaction processes inside the slurry. The results show that the reaction rate accelerates when the reaction temperature increases, and reaches its maximum at about 490 K, but if temperature is higher than 510 K, the reaction rate decreases rapidly. The whole reaction process is controlled by the reaction at the surface of the catalyst particles. The mass transfer resistance at gas-liquid interface and that from the bulk liquid phase to the surface of the catalyst particle can be neglected. The apparent reaction rate is zero order for toluene concentration and first order for hydrogen concentration in the liquid phase. The kinetic model is obtained. The kinetic model fits the experimental data very well. The apparent activation energy of the hydrogen absorption reaction of MlNi_5-toluene slurry system is 41.01 kJ·mol^(-1).展开更多
Deoxo 6 deoxy 6,9 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (1), 9 deoxo 11 deoxy 9,11 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (2) and 9 a aza 9 a ...Deoxo 6 deoxy 6,9 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (1), 9 deoxo 11 deoxy 9,11 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (2) and 9 a aza 9 a homoerythromycin cyclic lactam (3) were synthesized by the Beckmann rearrangement of erythromycin A 9 (E) oxime (4). The structures of compounds (1), (2) and (3) have been identified by their spectral data. The reaction mechanism was also discussed. The yield of the Beckmann rearrangement of compounds (4) was better than that reported in literatures.展开更多
A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o...A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.展开更多
Cu-Zn-Al slurry catalysts were prepared using a complete liquid-phase preparation technology under different heat treatment atmospheres.The catalysts were characterized using X-ray diffraction,X-ray photoelectron spec...Cu-Zn-Al slurry catalysts were prepared using a complete liquid-phase preparation technology under different heat treatment atmospheres.The catalysts were characterized using X-ray diffraction,X-ray photoelectron spectroscope,and N2 adsorption-desorption.Their application in the single-step synthesis of dimethyl ether from syngas was also investigated.The results indicate that the type of heat treatment atmosphere has an influence on the Cu species and the Cu0/Cu+ ratio on the catalyst surface.Moreover,the final Cu/Zn ratio on the catalyst surface is mainly dependent on the composition and reaction environment of the catalyst and less on the type of heat treatment atmosphere.The prepared catalysts can suppress sintering of active sites at high temperatures,and the type of heat treatment atmosphere mainly affects the capability of the catalyst for methanol synthesis.The catalysts perform best using N2 as the heat treatment atmosphere.展开更多
The Beckmann rearrangement of cyclohexanone oxime was achieved by the combined use of cobalt salt and Lewis acids co-catalysts (each 10 mol%). Various combinations of cobalt salts and Lewis acids gave lactams in a sat...The Beckmann rearrangement of cyclohexanone oxime was achieved by the combined use of cobalt salt and Lewis acids co-catalysts (each 10 mol%). Various combinations of cobalt salts and Lewis acids gave lactams in a satisfactory yield under mild conditions. This method makes it possible to reduce undesirable byproducts.展开更多
The main problems with the liquid-phase technology of carbon fiber/aluminum matrix composites include poor wetting of the fiber with liquid aluminum and formation of aluminum carbide on the fibers’surface.This paper ...The main problems with the liquid-phase technology of carbon fiber/aluminum matrix composites include poor wetting of the fiber with liquid aluminum and formation of aluminum carbide on the fibers’surface.This paper aims to solve these problems.The theoretical and experimental dependence of porosity on the applied pressure were determined.The possibility of obtaining a carbon fiber/aluminum matrix composite wire with a strength value of about 1500 MPa was shown.The correlation among the strength of the carbon fiber reinforced aluminum matrix composite,the fracture surface,and the degradation of the carbon fiber surface was discussed.展开更多
Various types of gene rearrangements have been discovered in the mitogenoes of the frog family Ranidae. In this study, we determined the complete mitogenome sequence of three Rana frogs. By combining the available mit...Various types of gene rearrangements have been discovered in the mitogenoes of the frog family Ranidae. In this study, we determined the complete mitogenome sequence of three Rana frogs. By combining the available mitogenomic data sets from GenBank, we evaluated the phylogenetic relationships of Ranidae at the mitogenome level and analyzed mitogenome rearrangement cases within Ranidae. The three frogs shared an identical mitogenome organization that was extremely similar to the typical Neobatrachian-type arrangement. Except for the genus Babina, the monophyly of each genus was well supported. The genus Amnirana occupied the most basal position among the Ranidae. The [Lithobates + Rana] was the closest sister group of Odorrana. The diversity of mitochondrial gene arrangements in ranid species was unexpectedly high, with 47 mitogenomes from 40 ranids being classified into 10 different gene rearrangement types. Some taxa owned their unique gene rearrangement characteristics, which had significant implication for their phylogeny analysis. All rearrangement events discovered in the Ranidae mitogenomes can be explained by the duplication and random loss model.展开更多
Using Southern blot, Northern blot and Quick blot methods, we examined the rearrangement and expression of TCR βgene in four early differentiation stage cell lines from human hemopoietic system, namely HL-60, Jurkat,...Using Southern blot, Northern blot and Quick blot methods, we examined the rearrangement and expression of TCR βgene in four early differentiation stage cell lines from human hemopoietic system, namely HL-60, Jurkat, Daudi and Raji cells as well as lymphocytes from 17 acute lymphocytic leukemia (ALL) patients. The results showed. Ⅰ) Rearrangement of TCR βgene was seen in Jurkat cells. A germline pattern was observed in HL-60, Daudi and Raji cells. 2) Eight of 9 patients with T-ALL had cells with rearranged TCR βgene. But two of 3 patients with B-ALL and three of 5 patients with nonT, nonB-ALL also had cells with rearranged TCR βgene. 3) A 1.3 kb full-length transcript and a 1.0 kb truncated transcript were detected in Jurkat cells by probing with <sup>32</sup>P-TCR βcDNA. But some leukemic B cells also expressed an incompleted transcript. 4) TCR βmRNA was detected in six of 8 patients with T-ALL, four of 5 patients with nonT, nonB-ALL and one of 3 patients with B-ALL. But the level of expression was quite differ ent. The dual-rearrangement and the abnormal expression may give us a new clue for researching leukemogenesis.展开更多
Theoretical studies on the rearrangement reactions of nitropyrazoles have beeninvestigated. In order to gain a better understanding of the intermediate process of rearrangementreactions, the transition states of the r...Theoretical studies on the rearrangement reactions of nitropyrazoles have beeninvestigated. In order to gain a better understanding of the intermediate process of rearrangementreactions, the transition states of the rearrangement reactions were obtained by TS method at theB3LYP/6-311G(d, p) level of theory. The natural bond orbital charge, electrostatic potential andfrontier molecular orbital of the molecules in the process of rearrangement were analyzed, and thesolvent effect was also discussed. The rearrangement of nitropyrazoles involves two transitionstates and one intermediate, and the nitro group and hydrogen atom are two transfer groups forrearrangement reactions. The migration of these two groups leads to the change of chargedistribution and molecular structure. The structural changes of the molecules in different solventsare not significant, but the dipole moment of the molecule has obvious change.展开更多
The side reaction between the active material and liquid-electrolyte cause structural damage and particle pulverization is one of the important factors leading to the capacity decay of LiNi0.80Co0.15Al0.05O2(NCA)mater...The side reaction between the active material and liquid-electrolyte cause structural damage and particle pulverization is one of the important factors leading to the capacity decay of LiNi0.80Co0.15Al0.05O2(NCA)materials in Li ion batteries(LIBs).Surface modification is an effective strategy for NCA cathodes,which could alleviate the degradation associated with surface processes.Herein,a surface structure rearrangement of NCA cathode secondary particles was reported by in-situ forming a solid electrolyte LiBO2.The LiBO2 is beneficial for alleviating the stress during charge/discharge process,thereby slowing down the rate of cracks formation in the secondary particles,which facilitates the Li+de-intercalation as well as prevents penetration of the liquid-electrolyte into the interior of the particles.As a result,the surface structure rearrangement NCA(RS-NCA)delivers a high discharge capacity of 202.5 m Ah g^-1 at 0.1 C,and exhibits excellent cycle stability with discharge capacity retaining 148 m Ah g^-1 after 200 cycles at 2 C.This surface structure rearrangement approach provides a new viewpoint in designing high-performance high-voltage LIBs.展开更多
基金supported by the National Key R&D Program of China(2023YFD1701504)the 2115 Talent Development Program of China Agricultural University Fund(1011-00109018)the Beijing Innovation Team of the Modern Agricultural Research System(BAIC08-2023-FQ02)。
文摘Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO_(2))that achieved 96.6%yield for the hydrogenation rearrangement of furfural to cyclopentanone at mild conditions(1 MPaH_(2),150°C).The turnover frequency of Ni-P/mSiO_(2)was 411.9 h^(-1),which was 3.2-fold than that of Ni/mSiO_(2)(127.2 h^(-1)).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were generated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density functional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.
基金supported by the National Key Research and Development Plan (2018YFC1900203)The National Science Fund for Distinguished Young Scholars (52000094)The National Natural Science Foundation of China (51968033)。
文摘Pd/Cu liquid-phase composite was utilized as the catalyst in this study to remove PH_(3) at low temperatures.The anti-heterotoxicity of catalysts in the PH_(3) catalytic oxidation purification process was carefully explored and pioneered.The catalytic performance,thermodynamics,kinetics,and catalytic oxidation mechanism of Pd/Cu liquid-phase catalyst catalytic oxidation of PH_(3) were thoroughly investigated.The results showed that Pd/Cu has a superior catalytic effect on the removal of PH_(3) in the gas mixture under low temperature.With CO as the carrier gas,the removal efficiency of PH_(3) could be maintained at 100%for nearly 450 min,indicating that the Pd/Cu liquid phase catalyst has good resistance to heterotoxicity.According to the thermodynamic,kinetic,and related characterization results of the PH_(3) purification process,the kinetic region of the gas–liquid reaction of PH_(3) absorption by Pd/Cu solution was an interfacial reaction.Pd was the primary catalyst and Cu was the secondary catalyst,and the adsorption of PH_(3)was a primary reaction.PH_(3) was spontaneously oxidized to H_(3)PO_(4) in the Pd/Cu catalytic system during the removal process.Pd was regenerated by O_(2) and Cu,increasing the activity and stability of the Pd/Cu catalyst in the sustain and efficient purification of PH_(3) in tail gas.
基金support from the National Natural Science Foundation of China (Nos. 22178158, 52162014 and 22065024)Science and Technology Project of Education Department of Jiangxi Province (No. GJJ2200402)+3 种基金Jiangxi Provincial Natural Science Foundation (No. 20224BAB213023)the Outstanding Youth Science Fund Project of Jiangxi Province (No. 20224ACB213008)the Jiangxi Provincial Double Thousand Talents Plan-Youth Program (No. S2021GDQN0947)Natural Science Foundation of Chongqing (No. 2023NSCQ-MSX0052)
文摘Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O-containing value-added chemicals thereby replacing the traditional petroleum-based approaches.The scope for developing efficient bifunctional catalysts and establishing mild reaction conditions for upgrading furfurals to cyclic compounds has stimulated immense deliberation in recent years.Extensive efforts have been made toward developing catalysts for multiple tandem conversions,including those with various metals and supports.In this scientific review,we aim to summarize the research progress on the synergistic effect of the metal-acid sites,including simple metal-supported acidic supports,adjacent metal acid sites-supported catalysts,and in situ H_(2)-modified bifunctional catalysts.Distinctively,the catalytic performance,catalytic mechanism,and future challenges for the hydrogenative rearrangement are elaborated in detail.The methods highlighted in this review promote the development of C_(5) cyclic compound synthesis and provide insights to regulate bifunctional catalysis for other applications.
基金support from the Natural Science Foundation of Gansu Province(No.3ZS061-A25-019)the Scientific Research fund of Gansu Provincial Education Department(No.0601-25)
文摘Under mild conditions, conversion of a variety of ketoximes and aldoximes to their corresponding amides and nitriles proceeded in the presence of PEG-SO3H with high yields.
基金Supported by The Scientific Research Foundation of the Ministry of Health,China,the Medical and Health Science Foundation,Zhejiang Province,China,No.WKJ-2009-2-021
文摘AIM:To study the diagnostic value of immunoglobulin heavy chain(IgH)and T-cell receptorγ (TCR-γ)gene monoclonal rearrangements in primary gastric lymphoma(PGL).METHODS:A total of 48 patients with suspected PGL at our hospital were prospectively enrolled in this study from January 2009 to December 2011.The patients were divided into three groups(a PGL group,a gastric linitis plastica group,and a benign gastric ulcer group)based on the pathological results(gastric mucosal specimens obtained by endoscopy or surgery)and follow-up.Endoscopic ultrasonography(EUS)and EUSguided biopsy were performed in all the patients.The tissue specimens were used for histopathological examination and for IgH and TCR-γ gene rearrangement polymerase chain reaction analyses.RESULTS:EUS and EUS-guided biopsy were successfully performed in all 48 patients.In the PGL group(n=21),monoclonal IgH gene rearrangements were detected in 14(66.7%)patients.A positive result for each set of primers was found in 12(57.1%),8(38.1%),and 4(19.0%)cases using FR1/JH,FR2/JH,and FR3/JH primers,respectively.Overall,12(75%)patients with mucosal-associated lymphoid tissue lymphoma(n=16)and 2(40%)patients with diffuse large B-cell lymphoma(n=5)were positive for monoclonal IgH gene rearrangements.No patients in the gastric linitis plastica group(n=17)and only one(10%)patient in the benign gastric ulcer group(n=10)were positive for a monoclonal IgH gene rearrangement.No TCRgene monoclonal rearrangements were detected.The sensitivity of monoclonal IgH gene rearrangements was 66.7%for a PGL diagnosis,and the specificity was96.4%.In the PGL group,8(100%)patients with stage IIE PGL(n=8)and 6(46.1%)patients with stage IE PGL(n=13)were positive for monoclonal IgH gene rearrangements.CONCLUSION:IgH gene rearrangements may be associated with PGL staging and may be useful for the diagnosis of PGL and for differentiating between PGL and gastric linitis plastica.
基金Supported by The National Center for Global Health and Medicine
文摘Acquired immune deficiency syndrome (AIDS)-related lymphoma (ARL) remains the main cause of AIDS-related deaths in the highly active anti-retroviral therapy (HAART) era. Recently, rearrangement of MYC is associated with poor prognosis in patients with diffuse large B-cell lymphoma. Here, we report a rare case of gastrointestinal (GI)-ARL with MYC rearrangements and coinfected with Epstein-Barr virus (EBV) infection presenting with various endoscopic findings. A 38-yearold homosexual man who presented with anemia and was diagnosed with an human immunodeficiency virus infection for the first time. GI endoscopy revealed multiple dish-like lesions, ulcerations, bloody spots, nodular masses with active bleeding in the stomach, erythematous flat lesions in the duodenum, and multiple nodular masses in the colon and rectum. Magnified endoscopy with narrow band imaging showed a honeycomb-like pattern without irregular microvessels in the dish-like lesions of the stomach. Biopsy specimens from the stomach, duodenum, colon, and rectum revealed diffuse large B-cell lymphoma concomitant with EBV infection that was detected by high tissue EBV-polymerase chain reaction levels and Epstein-Barr virus small RNAs in situ hybridization. Fluorescence in situ hybridization analysis revealed a fusion between the immunoglobulin heavy chain (IgH) and c-MYC genes, but not between the IgH and BCL2 loci. After 1-mo of treatment with HAART and R-CHOP, endoscopic appearance improved remarkably, and the histological features of the biopsy specimens revealed no evidence of lymphoma. However, he died from multiple organ failure on the 139 th day after diagnosis. The cause of his poor outcome may be related to MYC rearrangement. The GI tract involvement in ARL is rarely reported, and its endoscopic findings are various and may be different from those in non-AIDS GI lymphoma; thus, we also conducted a literature review of GI-ARL cases.
文摘Caprolactam, which is mainly produced via the Beckmann rearrangement reaction, is an important chemical material. The strict specifications of caprolactam products make the refining process of caprolactam extremely important. According to the different rearrangement process, the refining process of caprolactam is also different. The main refining sequence of liquid phase rearrangement products includes extraction, ion exchange, hydrogenation, and distillation. The refining process of gas phase rearrangement products is conducted mainly through distillation, crystallization, and hydrogenation. In this paper, the research progress of caprolactam refining technology will be summarized according to different rearrangement reaction processes, which will provide a reference for the selection of appropriate caprolactam refining process.
基金Supported by the National Natural Science Foundation of China(Nos.20771030,20671025)
文摘Six Brnsted acidic ionic liquids(ILs) 1a―1f were synthesized and used as the dual solvent-catalyst systems for Beckmann rearrangement reactions. Among ILs 1a―1f, IL 1a exhibited the highest catalytic activity and successfully catalyzed the Beckmann rearrangement of ketoximes, and the corresponding amides were obtained in good to excellent yields(74%―92%). In addition, IL 1a could be recovered easily and reused at least three times without any loss of catalytic activity.
基金Sponsored by the Natural Science Foundation of Zhejiang Province (No. Y4100620)the Research Foundation of Education Bureau of Zhejiang Province (No. Y200906517)
文摘The reaction mechanism of amadori rearrangement in the initial stage of Maillard reaction has been investigated by means of density functional theory calculations in the gaseous phase and aqueous solution.Cyclic ribose and glycine were taken as the model in the amadori rearrangement.Reaction mechanisms have been proposed,and possibility for the formation of different compounds has been evaluated through calculating the relative energy changes for different steps of the reaction by following the total mass balance.The calculations reveal that the amadori rearrangement initialized via the intramolecular rearrangement,transferring one proton from N(3) to O(4) atom.In the next step,the second proton is also transferred from N(3) to O(4) atom,corresponding to the cleavage of C(4)-O(4) bond and the release of one water molecule.Then another proton is transferred from N(3) to C(5) atom via TS3 with the reaction barrier of 58.3 kcal·mol-1 after tunneling the effect correction calculated at the B3LYP/6-31+G(d) level of theory,and this step is rate limiting for the whole catalytic cycle.Ultimately,the product is generated via keto-enolic tautomerization.Present calculation could provide insights into the reaction mechanism of Maillard reaction since experimental evaluation of the role of intermediates in the Maillard reaction is quite complicated.
文摘The rearrangement of Bcl-1 gene (Bcl-1/IgH rearrangement) and expression of cyclin D1 in multiple myeloma (MM) precursor cells were studied and the role of cyclin D1 in the pathogenesis of MM was investigated. The BCL-1 rearrangement and cyclin D1 protein expression in 15 cases of MM were detected. By using hemi-nested polymerase chain reaction (PCR) the genomic DNA from fresh peripheral blood and bone marrow was amplified and the expression of cyclin D1 in the smears was detected by using immunohistochemical method. Ten volunteer with normal bone marrow served as control group. The results showed Bcl-1 rearrangement was detectable in 3/15 (20 %) MM patients and cyclin D, expression in 4/15 (27 % ) MM patients. BeLl-1 rearrangement and cyclin D1 protein expression were also detected in MM precursor cells. No overexpression of cyclin D1 or the rearrangement of the BeL-1 gene was found in the 10 volunteers. It was concluded that Bel-1 rearrangement and cyclin D1 protein overexpression were detected in MM precursor cells, speculating that overexpression of cyclin D1 protein may play an initial (critical) role in the pathogenesis of MM.
文摘The kinetics of liquid-phase hydrogenation of toluene catalyzed by MlNi_5 was studied by investigating the influences of the reaction temperature and pressure on the mass transfer-reaction processes inside the slurry. The results show that the reaction rate accelerates when the reaction temperature increases, and reaches its maximum at about 490 K, but if temperature is higher than 510 K, the reaction rate decreases rapidly. The whole reaction process is controlled by the reaction at the surface of the catalyst particles. The mass transfer resistance at gas-liquid interface and that from the bulk liquid phase to the surface of the catalyst particle can be neglected. The apparent reaction rate is zero order for toluene concentration and first order for hydrogen concentration in the liquid phase. The kinetic model is obtained. The kinetic model fits the experimental data very well. The apparent activation energy of the hydrogen absorption reaction of MlNi_5-toluene slurry system is 41.01 kJ·mol^(-1).
文摘Deoxo 6 deoxy 6,9 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (1), 9 deoxo 11 deoxy 9,11 epoxy 9,9 a didehydro 9 a aza 9 a homoerythromycin A (2) and 9 a aza 9 a homoerythromycin cyclic lactam (3) were synthesized by the Beckmann rearrangement of erythromycin A 9 (E) oxime (4). The structures of compounds (1), (2) and (3) have been identified by their spectral data. The reaction mechanism was also discussed. The yield of the Beckmann rearrangement of compounds (4) was better than that reported in literatures.
文摘A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.
基金supported by the National Natural Science Foundation of China(No.20706039)the National Basic Research Program(973 Program) of China (No.2005CB221204)+1 种基金the Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi of China in 2010the Young Scientific and the Technical Fund of Shanxi of China (No.2006021010)
文摘Cu-Zn-Al slurry catalysts were prepared using a complete liquid-phase preparation technology under different heat treatment atmospheres.The catalysts were characterized using X-ray diffraction,X-ray photoelectron spectroscope,and N2 adsorption-desorption.Their application in the single-step synthesis of dimethyl ether from syngas was also investigated.The results indicate that the type of heat treatment atmosphere has an influence on the Cu species and the Cu0/Cu+ ratio on the catalyst surface.Moreover,the final Cu/Zn ratio on the catalyst surface is mainly dependent on the composition and reaction environment of the catalyst and less on the type of heat treatment atmosphere.The prepared catalysts can suppress sintering of active sites at high temperatures,and the type of heat treatment atmosphere mainly affects the capability of the catalyst for methanol synthesis.The catalysts perform best using N2 as the heat treatment atmosphere.
文摘The Beckmann rearrangement of cyclohexanone oxime was achieved by the combined use of cobalt salt and Lewis acids co-catalysts (each 10 mol%). Various combinations of cobalt salts and Lewis acids gave lactams in a satisfactory yield under mild conditions. This method makes it possible to reduce undesirable byproducts.
基金financially supported by ISSP RAS-Russian Government contracts
文摘The main problems with the liquid-phase technology of carbon fiber/aluminum matrix composites include poor wetting of the fiber with liquid aluminum and formation of aluminum carbide on the fibers’surface.This paper aims to solve these problems.The theoretical and experimental dependence of porosity on the applied pressure were determined.The possibility of obtaining a carbon fiber/aluminum matrix composite wire with a strength value of about 1500 MPa was shown.The correlation among the strength of the carbon fiber reinforced aluminum matrix composite,the fracture surface,and the degradation of the carbon fiber surface was discussed.
基金supported by the Innovative Research Team in University of Sichuan Bureau of Education (No.14TD0002)the Scientific Research Fund of Sichuan Provincial Education Department (No.11ZA077)
文摘Various types of gene rearrangements have been discovered in the mitogenoes of the frog family Ranidae. In this study, we determined the complete mitogenome sequence of three Rana frogs. By combining the available mitogenomic data sets from GenBank, we evaluated the phylogenetic relationships of Ranidae at the mitogenome level and analyzed mitogenome rearrangement cases within Ranidae. The three frogs shared an identical mitogenome organization that was extremely similar to the typical Neobatrachian-type arrangement. Except for the genus Babina, the monophyly of each genus was well supported. The genus Amnirana occupied the most basal position among the Ranidae. The [Lithobates + Rana] was the closest sister group of Odorrana. The diversity of mitochondrial gene arrangements in ranid species was unexpectedly high, with 47 mitogenomes from 40 ranids being classified into 10 different gene rearrangement types. Some taxa owned their unique gene rearrangement characteristics, which had significant implication for their phylogeny analysis. All rearrangement events discovered in the Ranidae mitogenomes can be explained by the duplication and random loss model.
文摘Using Southern blot, Northern blot and Quick blot methods, we examined the rearrangement and expression of TCR βgene in four early differentiation stage cell lines from human hemopoietic system, namely HL-60, Jurkat, Daudi and Raji cells as well as lymphocytes from 17 acute lymphocytic leukemia (ALL) patients. The results showed. Ⅰ) Rearrangement of TCR βgene was seen in Jurkat cells. A germline pattern was observed in HL-60, Daudi and Raji cells. 2) Eight of 9 patients with T-ALL had cells with rearranged TCR βgene. But two of 3 patients with B-ALL and three of 5 patients with nonT, nonB-ALL also had cells with rearranged TCR βgene. 3) A 1.3 kb full-length transcript and a 1.0 kb truncated transcript were detected in Jurkat cells by probing with <sup>32</sup>P-TCR βcDNA. But some leukemic B cells also expressed an incompleted transcript. 4) TCR βmRNA was detected in six of 8 patients with T-ALL, four of 5 patients with nonT, nonB-ALL and one of 3 patients with B-ALL. But the level of expression was quite differ ent. The dual-rearrangement and the abnormal expression may give us a new clue for researching leukemogenesis.
文摘Theoretical studies on the rearrangement reactions of nitropyrazoles have beeninvestigated. In order to gain a better understanding of the intermediate process of rearrangementreactions, the transition states of the rearrangement reactions were obtained by TS method at theB3LYP/6-311G(d, p) level of theory. The natural bond orbital charge, electrostatic potential andfrontier molecular orbital of the molecules in the process of rearrangement were analyzed, and thesolvent effect was also discussed. The rearrangement of nitropyrazoles involves two transitionstates and one intermediate, and the nitro group and hydrogen atom are two transfer groups forrearrangement reactions. The migration of these two groups leads to the change of chargedistribution and molecular structure. The structural changes of the molecules in different solventsare not significant, but the dipole moment of the molecule has obvious change.
基金the National Natural Science Foundation of China(51764048,51703118 and 51474191)Yunnan Province Thousand Youth Talents Plan+1 种基金the Application Basis Research Project of Yunnan Province Science and Technology Department(2017FD144)Key Natural Science Foundation of Yunnan Province China(2018FA28)for providing the financial support。
文摘The side reaction between the active material and liquid-electrolyte cause structural damage and particle pulverization is one of the important factors leading to the capacity decay of LiNi0.80Co0.15Al0.05O2(NCA)materials in Li ion batteries(LIBs).Surface modification is an effective strategy for NCA cathodes,which could alleviate the degradation associated with surface processes.Herein,a surface structure rearrangement of NCA cathode secondary particles was reported by in-situ forming a solid electrolyte LiBO2.The LiBO2 is beneficial for alleviating the stress during charge/discharge process,thereby slowing down the rate of cracks formation in the secondary particles,which facilitates the Li+de-intercalation as well as prevents penetration of the liquid-electrolyte into the interior of the particles.As a result,the surface structure rearrangement NCA(RS-NCA)delivers a high discharge capacity of 202.5 m Ah g^-1 at 0.1 C,and exhibits excellent cycle stability with discharge capacity retaining 148 m Ah g^-1 after 200 cycles at 2 C.This surface structure rearrangement approach provides a new viewpoint in designing high-performance high-voltage LIBs.