BACKGROUND Radiotherapy is widely employed in colorectal cancer(CRC)treatment,but the occurrence of radioresistance severely limits the clinical benefit to patients and significantly contributes to treatment failure a...BACKGROUND Radiotherapy is widely employed in colorectal cancer(CRC)treatment,but the occurrence of radioresistance severely limits the clinical benefit to patients and significantly contributes to treatment failure and recurrent metastasis.AIM To explore the role and underlying mechanism of the lncRNA FTX in radiotherapy resistance in CRC.METHODS LncRNA FTX expression in colorectal parent cells(HT29 and HCT116)and radioresistant cells(HT29R and HCT116R)was determined by real-time quantitative PCR,and the viability of HT29R-shFTX and HCT116R-shFTX cells under ionizing radiation was evaluated using the cell counting kit-8 assay and colony formation experiment.The levels of glutathione and reactive oxygen species in cells after irradiation were determined,and the association between ferroptosis and lncRNA FTX expression in cancer cells was tested.A dual-luciferase assay was used to validate gene interactions.A xenotransplantation mouse model was established to explore the effects of FTX on the CRC tumor radiosensitivity in vivo.RESULTS FTX was upregulated in radioresistant CRC cells,and FTX knockdown inhibited cell survival and increased cell ferroptotic death in response to ionizing radiation.Moreover,lncRNA FTX restricted the SLC7A11 expression by sponging with miR-625-5p,and inhibition of the lncRNA FTX or SLC7A11 significantly increased cellular oxidant levels and DNA damage to ionizing radiation in cancer cells.However,SLC7A11 overexpression reversed the effects of decreased FTX levels on ferroptosis and high oxidation levels in cancer cells exposed to ionizing radiation.CONCLUSION Inhibition of the lncRNA FTX/miR-625-5p/SLC7A11 axis can induce ferroptosis and disturb intracellular redox balance,further sensitizing CRC cells to ionizing radiation,suggesting its potential as a therapeutic target for improving CRC response to radiation therapy.展开更多
Historically seen as a limitation,grain boundaries(GBs)within polycrystalline metal halide perovskite(MHP)films are thought to impede charge transport,adversely impacting the efficiency of perovskite solar cells(PSCs)...Historically seen as a limitation,grain boundaries(GBs)within polycrystalline metal halide perovskite(MHP)films are thought to impede charge transport,adversely impacting the efficiency of perovskite solar cells(PSCs).In this study,we employ home-built confo-cal photoluminescence microscopy,combined with photocurrent detec-tion modules,to directly visualize the carrier dynamics in the MHP film of PSCs under real operating conditions.Our findings suggest that GBs in high-efficiency PSCs function as carrier transport channels,where a notable enhancement in photocurrent is observed.Femtosecond transient absorption and Kelvin probe force microscopy measurements further validate the existence of a built-in electric field in the vicinity of GBs,offering additional driving force for charge separation and establishing channels for swift carrier transport along the GBs,thereby expediting subsequent charge collection processes.This study elucidates the pivotal role of GBs in operational PSCs and provides valuable insights for the fabrication of high-efficiency PSCs.展开更多
The deep seabed is known for its abundant reserves of various mineral resources.Notably,the Clarion Clipperton(C-C)mining area in the northeast Pacific Ocean,where China holds exploration rights,is particularly rich i...The deep seabed is known for its abundant reserves of various mineral resources.Notably,the Clarion Clipperton(C-C)mining area in the northeast Pacific Ocean,where China holds exploration rights,is particularly rich in deep-sea polymetallic nodules.These nodules,which are nodular and unevenly distributed in seafloor sediments,have significant industrial exploitation value.Over the decades,the deep-sea mining industry has increasingly adopted systems that combine rigid and flexible risers supported by large surface mining vessels.However,current systems face economic and structural stability challenges,hindering the development of deep-sea mining technology.This paper proposes a new structural design for a deep-sea mining system based on flexible risers,validated through numerical simulations and experimental research.The system composition,function and operational characteristics are comprehensively introduced.Detailed calculations determine the production capacity of the deep-sea mining system and the dimensions of the seabed mining subsystem.Finite element numerical simulations analyze the morphological changes of flexible risers and the stress conditions at key connection points under different ocean current incident angles.Experimental research verifies the feasibility of collaborative movement between two tethered underwater devices.The proposed deep-sea mining system,utilizing flexible risers,significantly advances the establishment of a commercial deep-sea mining system.The production calculations and parameter determinations provide essential references for the system’s future detailed design.Furthermore,the finite element simulation model established in this paper provides a research basis,and the method established in this paper offers a foundation for subsequent research under more complex ocean conditions.The control strategy for the collaborative movement between two tethered underwater devices provides an effective solution for deep-sea mining control systems.展开更多
AIM： To investigate the cyclooxygenase-2 （COX-2） expression level in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth in...AIM： To investigate the cyclooxygenase-2 （COX-2） expression level in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth inhibition and cell apoptosis. METHODS： Hepatoma cells were cultured and treated with celecoxib. Cell in situ hybridization （ISH） and immunocytochemistry were used to detect COX-2 mRNA and protein expression. Proliferating cell nuclear antigen and phosphorylated Akt were also detected by immunocytochemistry assay. Cell growth rates were assessed by 3-（4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium （MTT） bromide colorimetric assay. Celecoxib- induced cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） and flow cytometry （FCM）. The phosphorylated Akt and activated fragments of caspase-9, caspase-3 were examined by Western blotting analysis. RESULTS： Increased COX-2 mRNA and protein expression were detected in all three hepatoma cell lines. Celecoxib could significantly inhibit cell growth and the inhibitory effect was in a dose- and time-dependent manner evidenced by MTT assays and morphological changes. The apoptotic index measured by TUNEL increased correspondingly with the increased concentration of celecoxib and the reaction time. With 50 μmol/L celecoxib treatment for 24 h, the apoptotic index of HepG2, BEL-7402 and SMMC-7721 cells was 25.01±3.08%, 26.40±3.05%,and 30.60±2.89%, respectively. Western blotting analysis showed remarkable activation of caspase-9, caspase-3 and dephosphorylation of Akt （Thr^308）. Immunocytochemistry also showed the reduction of PCNA expression and phosphorylation Akt （Thr^308） after treatment with celecoxib. CONCLUSION： COX-2 mRNA and protein overexpression in HepG2, Bel-7402 and SMMC-7721 cell lines correlate with the increased cell growth rate. Celecoxib can inhibit proliferation and induce apoptosis of hepatoma cell strains in a dose- and time-dependent manner.展开更多
Heat stress(HS)reaction can lead to serious physiological dysfunction associated with cardiovascular and various organ diseases.Ginsenoside Rg3(G-Rg3)is a representative component of ginseng rare saponin and can prote...Heat stress(HS)reaction can lead to serious physiological dysfunction associated with cardiovascular and various organ diseases.Ginsenoside Rg3(G-Rg3)is a representative component of ginseng rare saponin and can protect against multiple organs,also used as functional food to adjust the balance of the human body,but the therapeutic effect and molecular mechanism of G-Rg3 on male diseases under HS are underexplored.The aim of the present study,G-Rg3 was prepared through the efficient conversion of ginsenoside Rd and investigate the contribution of G-Rg3 to testicular injury induced exposure to HS.All mice were divided into four groups as follows:normal group,HS group,and HS+G-Rg3(5 and 10 mg/kg)groups.G-Rg3 was administered orally for 14 days,then exposed to a single scrotal heat treatment(43°C,18min)on the 7th day.After HS treatment,the morphology of testis and epididymis changes,and caused a significant loss of multinucleated giant cells,desquamation of germ cells in destructive seminiferous tubules,and degenerative Leydig cells,further destroying the production of sperm.After administration G-Rg3(5 and 10 mg/kg/day)for 2 weeks,the spermatogenic-related indexes of testosterone levels and superoxide dismutase(SOD)activity,glutathione(GSH)content significantly(p<0.01)increase compared with the HS group.Moreover,G-Rg3 treatment effectively ameliorated the production of malondialdehyde(MDA)(p<0.05 or p<0.01).Importantly,G-Rg3 exhibited the protective potential against HS-induced injury not only suppressing the protein levels of heme oxygenase-1(HO-1),hypoxia-inducible factor-1α(HIF-1α),and heat shock protein 70(HSP70)but also modulating the Bcl-2 family(p<0.01 or p<0.001)and activation of mitogen-activated protein kinase(MAPK)signaling pathways(p<0.01).For most of the parameters tested,the HS+G-Rg3(10 mg/kg)group exhibited potent effects compared with those exhibited by the low dose(5 mg/kg)group.In conclusion,the present study demonstrated that G-Rg3 exerted protective effects against HS-induced testicular dysfunction via inhibiting the MAPK-mediated oxidative stress and apoptosis in mice.展开更多
Detection of circulating tumor-specific DNA, RNA or proteins can be difficult due to relative scarcity. Exosomes are extracellular vesicles, 30 - 150 nm in diameter derived from fusion of multivesicular bodies with th...Detection of circulating tumor-specific DNA, RNA or proteins can be difficult due to relative scarcity. Exosomes are extracellular vesicles, 30 - 150 nm in diameter derived from fusion of multivesicular bodies with the plasma membrane. They are composed of a lipid bilayer membrane and contain proteins, mRNA and miRNA. Exosomes are secreted by multiple cell types, including cancer cells. However, there is a relative lack of information concerning the contents of exosomes secreted by various tumor cell types. To examine exosomes in cancer, we collected blood plasma samples from patients with breast, ovarian, prostate, hepatic, gastric, colon, and pancreatic cancers. Exosomes were isolated from plasma and confirmed by AchE assay, transmission electron microscopy and expression of the CD63 exosomal marker. Expression of AFP, CA724, CA153, CEA, CA125, CA199 and PSA antigens were determined using an automated electro-chemiluminescence assay. Expression of the tumor-related chaperone protein, mortalin, was determined by Western blot analysis. Levels of exosome secretion were variable among the different tumor types. Both exosome levels and mortalin expression within tumor cell exosomes were higher than in healthy donors, except in pancreatic carcinoma, where exosomes were elevated but mortalin expression was not significantly different from healthy donors. Exosomes provide unique opportunities for the enrichment of tumor-specific materials and may be useful as biomarkers and possibly as tools of cancer therapies. Mortalin, which has been linked to cell proliferation and induction of epithelial-mesenchymal transition of cancer cells, may be useful as a prognostic biomarker and as a possible therapeutic target.展开更多
Xiongdankaiming tablet (XDKMT), a well-known compound in traditional Chinese medicine, is widely used for the treatment of acute iridocyclitis and primary open-angle glaucoma. In this paper, accurate and reliable meth...Xiongdankaiming tablet (XDKMT), a well-known compound in traditional Chinese medicine, is widely used for the treatment of acute iridocyclitis and primary open-angle glaucoma. In this paper, accurate and reliable methods were developed for the identification of 20 constituents using high-performance liquid chromatography with photodiode array and electron spray ionization-mass spectrometry (HPLC-PDA/ESI-MSn ), and determination of nine of the constituents (chlorogenic acid, gentiopicroside, isochlorogenic acid B, diosmetin-7-O-β-D-glucopyranoside, apigenin, diosmetin, tauroursodeoxycholic acid, acacetin, and taurochenodeoxycholic acid) was developed using HPLC with ultraviolet absorption detector and evaporative light scattering detector (HPLC-UV/ELSD) for the first time. The best results were obtained on a Zorbax SB-C18 column with gradient elution using water (0.1% formic acid) (A) and methanol (0.1% formic acid) (B) at a flow rate of 0.7 ml/min. Tauroursodeoxycholic acid and taurochenodeoxycholic acid, owing to their low UV absorption, were detected by ELSD. The other seven compounds were analyzed by HPLC-UV with variable wavelengths. The calibration curves of all nine constituents showed good linear regression (R2 >0.9996) within the linearity ranges. The limits of detection and quantification were in the ranges of 0.0460-9.90 μg/ml and 0.115-24.8 μg/ml, respectively. The accuracy, in terms of recovery, varied from 95.3% to 104.9% with relative standard deviations (RSDs) less than 4.4%. Precision (with the intra- and inter-day variations less than 4.4%) was also suitable for its intended use. The developed method was successfully applied for the analysis of major components in XDKMT, which provides an appropriate method for the quality control of XDKMT.展开更多
[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterlo...[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterloggogenic type） in Jiangxi Province were chosen as test materials. The single and competitive adsorption behaviors of Cu and Pb in paddy soils were investigated with batch equilibrium method, and the environmental risk under coexistence of Cu and Pb in these soils was estimated with distribution coefficient. The results showed that under equal proportion, the adsorption affinity of Pb was greater than that of Cu in the two paddy soils, and the adsorption capacities in waterloggogenic paddy soil （WPS） were significantly higher than those in gley paddy soil （GTPS）, but the desorption capacities of Cu were greater than those of Pb in the two paddy soils, and the desorption capacities in GTPS were significantly higher than those in the WPS. The adsorption capacities of Cu and Pb ions under competitive condition were obviously lower than those in single system, while the desorption rates significantly increased. The potential environmental risk of Cu pollution was greater than that of Pb in paddy soils, and their environmental risk decreased with the increase of pH, but increased significantly under coexistence of lead and copper. [Conclusion] This research suggests that when Cu and Pb ions coexist in the paddy soils, compared with lead pollution, we should pay attention to the pollution of Cu.展开更多
The conversion efficiency of stimulated Raman scattering （SRS） in CH4 is studied by using a single longitudinal mode second-harmonic Nd：YAG laser （532 nm, linewidth 0.003 cm^-1, pulse-width （FWHM） 6.5 ns）. Due ...The conversion efficiency of stimulated Raman scattering （SRS） in CH4 is studied by using a single longitudinal mode second-harmonic Nd：YAG laser （532 nm, linewidth 0.003 cm^-1, pulse-width （FWHM） 6.5 ns）. Due to the heat release from vibrationally excited particles, SRS processes often suffer from the thermal defocusing effect （TDE）. In view of 6.5 ns laser pulse width is much shorter than the vibrational relaxation time of CH4 molecules, TDE can only affect the SRS processes afterwards. In the cases of low laser repetition, TDE will be not serious, because it will be removed by the thermal diffusion in Raman medium before the next pulse arrives. At the laser repetition rate 2 Hz, CH4 pressure 1.1 MPa and pump laser energy 95 mJ, the quantum conversion efficiency of backward first-Stokes （BS1） has attained 73%. This represents the highest first-stokes conversion efficiency in CH4. Furthermore, due to the relaxation oscillation, the BS1 pulses are narrowed to about 1.2 ns. As a result, the BS1 peak power turns out to be 2.7 times that of the pump. Its beam quality is also much better and is only slightly affected by TDE. This reason is that BS1 represents a wave-front-reversed replica of the pump beam, which can compensate the thermal distortions in Raman amplify process. Under the same conditions, but pump laser repetition rate as 10 Hz, the conversion efficiency of BS1 goes down to 36% due to TDE. From this study, we expect that a well-behaved 630 nm Raman laser may be designed by using a closed CH4/He circulating-cooling system, which may have some important applications.展开更多
Mixed halide perovskites(MHPs)are a class of semiconductor materials with great promise for many optoelectronic applications due to their outstanding photophysical properties.Understanding and tailoring the photogener...Mixed halide perovskites(MHPs)are a class of semiconductor materials with great promise for many optoelectronic applications due to their outstanding photophysical properties.Understanding and tailoring the photogenerated carrier dynamics is essential for further improvement of perovskite performance.Herein,we report a study about the carrier transport and interfacial charge transfer dynamics in Br-gradient MAPbI_(3-x)Br_(x) perovskite thin films prepared by surface ion-exchange method.Driven by the bandgap gradient in MAPbI_(3-x)Br_(x) films,the accelerated internal hole transport and enhanced interfacial extraction efficiency were both observed.Meanwhile,the interfacial electron transfer was also found to be evidently facilitated due to the surface modification during post-treatment.Our findings suggest the possibility of simultaneous acceleration of interfacial electron and hole transfer processes in halide perovskite films via surface post-treatment technique,which is of great importance in further improving the power conversion efficiency of perovskite solar cells.展开更多
To investigate the anaerobic fungal diversity in the rumen of gayals(Bos frontalis), Yunnan yellow cattle, yaks, and Tibetan yellow cattle, the ITS region of ruminal anaerobic fungi was sequenced. The anaerobic fungi ...To investigate the anaerobic fungal diversity in the rumen of gayals(Bos frontalis), Yunnan yellow cattle, yaks, and Tibetan yellow cattle, the ITS region of ruminal anaerobic fungi was sequenced. The anaerobic fungi found in four types of cattle could be divided into 16 groups(Neocallimastix, Anaeromyces, Orpinomyces, Caecomyces, Cyllamyces and unknown groups 1-11). There were 10 anaerobic fungal groups in the rumen of gayals, with three belonging to known genera(Orpinomyces, Neocallimastix, and Caecomyces), which accounted for 2.8% of sequences of gayals. There were fewer known anaerobic fungi in gayals than in Yunnan yellow cattle(Orpinomyces), yaks(Anaeromyces, Orpinomyces, and Cyllamyces) and Tibetan yellow cattle(Anaeromyces, Orpinomyces, Caecomyces, and Cyllamyces), accounting for 30.7%, 93.9%, and 35% of each of the relevant cattle species. The other seven unknown groups(NG1, NG4, NG6, NG7, NG9, NG10, and NG11) accounted for 91.6% of sequences from gayals, which was higher than Yunnan yellow cattle [69.3%(NG2, NG8 and NG9)], Tibetan yellow cattle [35%(NG4, NG5 and NG9)], and yaks [6.1%(NG3)]. Furthermore, NG1, NG6, NG7, NG10, and NG11 were only found in gayals,whereas NG3 and NG5 were found only in Tibetan yellow cattle and yak, respectively. Piromyces was not found in any of the four types of cattle. The anaerobic fungi abundance in the rumen of gayals was significantly higher than that of the other three types of cattle. The ruminal anaerobic fungi of gayals might have an important role in cellulose degradation, resulting in the ability of this species to successfully graze coarser fodder.展开更多
Adenylate cyclase(AC)is the key enzyme that catalyzes the formation of cAMP from ATP.In this study,we discovered two novel class Ⅲ ACs with a halophilic property from Thermobifida halotolerans DSM 44931(ThAC)and Halo...Adenylate cyclase(AC)is the key enzyme that catalyzes the formation of cAMP from ATP.In this study,we discovered two novel class Ⅲ ACs with a halophilic property from Thermobifida halotolerans DSM 44931(ThAC)and Haloactinopolyspora alba DSM 45211(HaAC),respectively.The recombinant ThAC and HaAC were expressed in Escherichia coli with molecular weights of 36.1 and 36.0 kDa respectively.The presence of 2500 and 2200 mmolL^(-1)1 NaCl significantly enhanced the enzyme activities of ThAC and HaAC,with 22-fold and 7.4-fold higher activities compared to those without NaCl,respectively.Several divalent metal ions were found to activate the recombinant ACs to different extents,and the optimal metal ion was Mg^(2+)for both ThAC and HaAC with concentrations of 80 mmol·L^(-1) and 40 mmol·L^(-1) respectively.Purified ThAC and HaAC had the optimal specific activities((4.59±0.35)×10^(4) and(7.76±0.52)×10^(4) U·mg^(-1))and catalytic efficiency(4.47 and 5.30 L·mmol^(-1)·s^(-1))at 45℃ and 40℃ respectively,while the optimum pH of both two recombinant ACs was 10.0.This is the first report of the halophilic Class III ACs,which could make new contributions to explore and study ACs for further associated investigations.展开更多
Organolead halide perovskite solar cells have attracted extensive interests in recent years. Thanks to innovations in materials process and technology, the power conversion efficiency (PCE) of perovskites-based solar ...Organolead halide perovskite solar cells have attracted extensive interests in recent years. Thanks to innovations in materials process and technology, the power conversion efficiency (PCE) of perovskites-based solar cells increases from 3.8% to 25.2%[1–4].In evaluating the quality of perovskite materials, a few key photophysical properties such as the lifetime, mobility and diffusion length of photogenerated carriers are usually measured.展开更多
Photophysical processes occurring within organic semiconductors is important for designing and fabricating organic solar cells.Copper phthalocyanine(CuPc)is a typical electron acceptor.In this work,the triplet exciton...Photophysical processes occurring within organic semiconductors is important for designing and fabricating organic solar cells.Copper phthalocyanine(CuPc)is a typical electron acceptor.In this work,the triplet exciton lifetime is prolonged by altering the molecular stacking pattern of the CuPc film.For CuPc thin films,the excited state decays are mainly determined by the triplet-triplet annihilation process.The ultrafast transient absorption measurements indicate that the primary annihilation mechanism is one-dimensional exciton diffusion collision destruction.The decay kinetics show a clearly time-dependent annihilation rate constant withγ∝t^(-1/2).Annihilation rate constants are determined to beγ0=(2.87±0.02)×10^(-20)cm^(3)·s^(-1/2)and(1.42±0.02)×10^(-20)cm^(3)·s^(-1/2)for upright and lyingdown configurations,respectively.Compared to the CuPc thin film with an upright configuration,the thin film with a lying-down configuration shows longer exciton lifetime and higher absorbance,which are beneficial to organic solar cells.The results in this work have important implications on the design and mechanistic understanding of organic optoelectronic devices.展开更多
The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskit...The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskite films.It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization.Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride(p-g-C_(3)N_(4))was successfully synthesized and doped into perovskite layer of carbon-based PSCs.The addition of p-g-C_(3)N_(4)into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide(MAPb I3)crystal for obtaining flat perovskite surface with larger grain size,but also reduces intrinsic defects of perovskite layer.It is found that thep-g-C_(3)N_(4) locates at the perovskite core,and the active groups-NH_(2)/NH_(3)and NH have a hydrogen bond strengthening,which effectively passivates electron traps and enhances the crystal quality of perovskite.As a result,a higher power conversion efficiency of 6.61% is achieved,compared with that doped with g-C_(3)N_(4)(5.93%)and undoped one(4.48%).This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.展开更多
Background Lignocellulose biomass is the most abundant and renewable material in nature.The objectives of this study were to characterize two endoglucanases Trep Cel3 and Trep Cel4,and determine the effect of the comb...Background Lignocellulose biomass is the most abundant and renewable material in nature.The objectives of this study were to characterize two endoglucanases Trep Cel3 and Trep Cel4,and determine the effect of the combination of them(1.2 mg Trep Cel3,0.8 mg Trep Cel4)on in vitro rumen fermentation characteristics.In this study,three nature lignocellulosic substrates(rice straw,RS;wheat straw,WS;leymus chinensis,LC)were evaluated for their in vitro digestibility,gas,NH3-N and volatile fatty acid(VFA)production,and microbial protein(MCP)synthesis by adding enzymatic combination.Methods Two endoglucanases’genes were successfully expressed in Escherichia coli(E.coli)BL21(DE3),and enzymatic characteristics were further characterized.The combination of Trep Cel3 and Trep Cel4 was incubated with lignocellulosic substrates to evaluate its hydrolysis ability.Results The maximum enzymatic activity of Trep Cel3 was determined at p H 5.0 and 40℃,while Trep Cel4 was at p H 6.0 and 50℃.They were stable over the temperature range of 30 to 60℃,and active within the p H range of 4.0 to 9.0.The Trep Cel3 and Trep Cel4 had the highest activity in lichenan 436.9±8.30 and 377.6±6.80 U/mg,respectively.The combination of Trep Cel3 and Trep Cel4 exhibited the highest efficiency at the ratio of 60:40.Compared to maximum hydrolysis of Trep Cel3 or Trep Cel4 separately,this combination was shown to have a superior ability to maximize the saccharification yield from lignocellulosic substrates up to 188.4%for RS,236.7%for wheat straw WS,222.4%for LC and 131.1%for sugar beet pulp(SBP).Supplemental this combination enhanced the dry matter digestion(DMD),gas,NH3-N and VFA production,and MCP synthesis during in vitro rumen fermentation.Conclusions The Trep Cel3 and Trep Cel4 exhibited the synergistic relationship(60:40)and significantly increased the saccharification yield of lignocellulosic substrates.The combination of them stimulated in vitro rumen fermentation of lignocellulosic substrates.This combination has the potential to be a feed additive to improve agricultural residues utilization in ruminants.If possible,in the future,experiments in vivo should be carried out to fully evaluate its effect.展开更多
The ionization processes of NH3 molecule are studied by photoelectron velocity map imaging technique in a linearly polarized 400-nm femtosecond laser field. The two-dimensional photoelectron images from ammonia molecu...The ionization processes of NH3 molecule are studied by photoelectron velocity map imaging technique in a linearly polarized 400-nm femtosecond laser field. The two-dimensional photoelectron images from ammonia molecules under different laser intensities are obtained. In the slow electron region, the values of kinetic energy of photoelectrons corresponding to peaks 1, 2, 3, and 4 are 0.27, 0.86, 1.16, and 1.6 eV, respectively. With both the kinetic energy and angular distribution of photoelectrons from NH3 molecules, we can confirm that the two-photon excited intermediate Rydberg state is A^1 A2" (v2'=3) state for photoelectron peaks 2, 3, 4, and the three peaks are marked as 1223 (2 + 2), 1123 (2 + 2), and 1023 (2 + 2) multi-photon processes, respectively. Then, peak 1 is found by adding a hexapole between the source chamber and the detection chamber to realize the rotational state selection and beam focusing. Peak 1 is labeled as the 1323 (3 + 1) multi-photon process through the intermediate Rydberg state E^1A1'. The phenomena of channel switching are found in the slow electron kinetic energy distributions. Our calculations and experimental results indicate that the stretching vibrational mode of ammonia molecules varies with channels, while the umbrella vibration does not. In addition, we consider and discuss the ac-Stark effect in a strong laser field. Peaks 5 and 6 are marked as (2 + 2 + 1) and (2 + 2 + 2) above threshold ionization processes in the fast electron region.展开更多
The above-threshold ionization process of ammonia molecules induced by a femtosecond laser field at 800 nm is studied in the intensity range from 1.6×10^(13) to 5.7×10^(13)W/cm^(2).Channel switching under di...The above-threshold ionization process of ammonia molecules induced by a femtosecond laser field at 800 nm is studied in the intensity range from 1.6×10^(13) to 5.7×10^(13)W/cm^(2).Channel switching under different laser intensities is observed and identified in the photoelectron kinetic energy spectra of ammonia.Based on the photoelectron kinetic energy distributions and the photoelectron angular distributions,the characteristic peaks observed are exclusively assigned to the multiphoton resonance through certain intermediate states,followed by multiphoton above-threshold ionization.展开更多
BACKGROUND The development of laparoscopic technology has provided a new choice for surgery of gastric cancer(GC),but the advantages and disadvantages of laparoscopic total gastrectomy(LTG)and laparoscopic-assisted to...BACKGROUND The development of laparoscopic technology has provided a new choice for surgery of gastric cancer(GC),but the advantages and disadvantages of laparoscopic total gastrectomy(LTG)and laparoscopic-assisted total gastrectomy(LATG)in treatment effect and safety are still controversial.The purpose of this study is to compare the efficacy and safety of the two methods in the treatment of GC,and to provide a basis for clinical decision-making.AIM To compare the efficacy of totally LTG(TLTG)and LATG in the context of radical gastrectomy for GC.Additionally,we investigated the safety and feasibility of the total laparoscopic esophagojejunostomy technique.METHODS Literature on comparative studies of the above two surgical methods for GC(TLTG group and LATG group)published before September 2022 were searched in the PubMed,Web of Science,Wanfang Database,CNKI,and other Chinese and English databases.In addition,the following search keywords were used:Gastric cancer,total gastrectomy,total laparoscopy,laparoscopy-assisted,esophagojejunal anastomosis,gastric/stomach cancer,total gastrectomy,totally/completely laparoscopic,laparoscopic assisted/laparoscopy assisted/laparoscopically assisted,and esophagojejunostomy/esophagojejunal anastomosis.Review Manager 5.3 software was used for the meta-analysis after two researchers independently screened the literature,extracted the data,and evaluated the risk of bias in the included studies.RESULTS After layer-by-layer screening,258 pieces of literature were recovered,and 11 of those pieces were eventually included.This resulted in a sample size of 2421 instances,with 1115 cases falling into the TLTG group and 1306 cases into the LATG group.Age or sex differences between the two groups were not statistically significant,according to the meta-analysis,however the average body mass index of the TLTG group was considerably higher than that of the LATG group(P=0.01).Compared with those in the LATG group,the incision length in the TLTG group was significantly shorter(P<0.001),the amount of intraoperative blood loss was significantly lower(P=0.003),the number of lymph nodes removed was significantly greater(P=0.04),and the time of first postoperative feeding and postoperative hospitalization were also significantly shorter(P=0.03 and 0.02,respectively).There were no significant differences in tumor size,length of proximal incisal margin,total operation time,anastomotic time,postoperative pain score,postoperative anal exhaust time,postoperative anastomosis-related complications(including anastomotic fistula,anastomotic stenosis,and anastomotic hemorrhage),or overall postoperative complication rate(P>0.05).CONCLUSION TLTG and esophagojejunostomy are safe and feasible.Compared with LATG,TLTG has the advantages of less trauma,less bleeding,easier access to lymph nodes,and faster postoperative recovery,and TLTG is also suitable for obese patients.展开更多
基金Supported by the National Natural Science Foundation of China,No.81960506Science and Technology Fund Project of Guizhou Provincial Health Commission,No.gzwkj2022-299Key Projects of Zunyi Science and Technology Fund,No.zunshikeheHZzi(2023)24 and No.zunshikeheHZzi(2024)9.
文摘BACKGROUND Radiotherapy is widely employed in colorectal cancer(CRC)treatment,but the occurrence of radioresistance severely limits the clinical benefit to patients and significantly contributes to treatment failure and recurrent metastasis.AIM To explore the role and underlying mechanism of the lncRNA FTX in radiotherapy resistance in CRC.METHODS LncRNA FTX expression in colorectal parent cells(HT29 and HCT116)and radioresistant cells(HT29R and HCT116R)was determined by real-time quantitative PCR,and the viability of HT29R-shFTX and HCT116R-shFTX cells under ionizing radiation was evaluated using the cell counting kit-8 assay and colony formation experiment.The levels of glutathione and reactive oxygen species in cells after irradiation were determined,and the association between ferroptosis and lncRNA FTX expression in cancer cells was tested.A dual-luciferase assay was used to validate gene interactions.A xenotransplantation mouse model was established to explore the effects of FTX on the CRC tumor radiosensitivity in vivo.RESULTS FTX was upregulated in radioresistant CRC cells,and FTX knockdown inhibited cell survival and increased cell ferroptotic death in response to ionizing radiation.Moreover,lncRNA FTX restricted the SLC7A11 expression by sponging with miR-625-5p,and inhibition of the lncRNA FTX or SLC7A11 significantly increased cellular oxidant levels and DNA damage to ionizing radiation in cancer cells.However,SLC7A11 overexpression reversed the effects of decreased FTX levels on ferroptosis and high oxidation levels in cancer cells exposed to ionizing radiation.CONCLUSION Inhibition of the lncRNA FTX/miR-625-5p/SLC7A11 axis can induce ferroptosis and disturb intracellular redox balance,further sensitizing CRC cells to ionizing radiation,suggesting its potential as a therapeutic target for improving CRC response to radiation therapy.
基金supported by the CAS Projects for Young Scientists in Basic Research(YSBR-007)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0970302)+4 种基金the National Natural Science Foundation of China(22233005,52272193)the DICP funding(I202315),the Natural Science Foundation of Liaoning(2024JH3/50100010)the LiaoNing Revitalization Talents Program(XLYC2203043)the Dalian Science and Technology Innovation Fund(2024RJ006)the Fundamental Research Funds for the Central Universities(DUT-22LAB602).
文摘Historically seen as a limitation,grain boundaries(GBs)within polycrystalline metal halide perovskite(MHP)films are thought to impede charge transport,adversely impacting the efficiency of perovskite solar cells(PSCs).In this study,we employ home-built confo-cal photoluminescence microscopy,combined with photocurrent detec-tion modules,to directly visualize the carrier dynamics in the MHP film of PSCs under real operating conditions.Our findings suggest that GBs in high-efficiency PSCs function as carrier transport channels,where a notable enhancement in photocurrent is observed.Femtosecond transient absorption and Kelvin probe force microscopy measurements further validate the existence of a built-in electric field in the vicinity of GBs,offering additional driving force for charge separation and establishing channels for swift carrier transport along the GBs,thereby expediting subsequent charge collection processes.This study elucidates the pivotal role of GBs in operational PSCs and provides valuable insights for the fabrication of high-efficiency PSCs.
基金Supported by Finance Science and Technology Project of Hainan Province under Grant No.ZDKJ2021027the National Natural Science Foundation of China under Grant No.52231012.
文摘The deep seabed is known for its abundant reserves of various mineral resources.Notably,the Clarion Clipperton(C-C)mining area in the northeast Pacific Ocean,where China holds exploration rights,is particularly rich in deep-sea polymetallic nodules.These nodules,which are nodular and unevenly distributed in seafloor sediments,have significant industrial exploitation value.Over the decades,the deep-sea mining industry has increasingly adopted systems that combine rigid and flexible risers supported by large surface mining vessels.However,current systems face economic and structural stability challenges,hindering the development of deep-sea mining technology.This paper proposes a new structural design for a deep-sea mining system based on flexible risers,validated through numerical simulations and experimental research.The system composition,function and operational characteristics are comprehensively introduced.Detailed calculations determine the production capacity of the deep-sea mining system and the dimensions of the seabed mining subsystem.Finite element numerical simulations analyze the morphological changes of flexible risers and the stress conditions at key connection points under different ocean current incident angles.Experimental research verifies the feasibility of collaborative movement between two tethered underwater devices.The proposed deep-sea mining system,utilizing flexible risers,significantly advances the establishment of a commercial deep-sea mining system.The production calculations and parameter determinations provide essential references for the system’s future detailed design.Furthermore,the finite element simulation model established in this paper provides a research basis,and the method established in this paper offers a foundation for subsequent research under more complex ocean conditions.The control strategy for the collaborative movement between two tethered underwater devices provides an effective solution for deep-sea mining control systems.
基金Supported by Medical Science Research Foundation of Jiangsu Health Bureau Grant Z200314 (to JL)Medical Science Research Foundation of Nanjing Medical University Grant NY1999023 (to NBL) and CX2003012 (to JL)
文摘AIM： To investigate the cyclooxygenase-2 （COX-2） expression level in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth inhibition and cell apoptosis. METHODS： Hepatoma cells were cultured and treated with celecoxib. Cell in situ hybridization （ISH） and immunocytochemistry were used to detect COX-2 mRNA and protein expression. Proliferating cell nuclear antigen and phosphorylated Akt were also detected by immunocytochemistry assay. Cell growth rates were assessed by 3-（4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium （MTT） bromide colorimetric assay. Celecoxib- induced cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） and flow cytometry （FCM）. The phosphorylated Akt and activated fragments of caspase-9, caspase-3 were examined by Western blotting analysis. RESULTS： Increased COX-2 mRNA and protein expression were detected in all three hepatoma cell lines. Celecoxib could significantly inhibit cell growth and the inhibitory effect was in a dose- and time-dependent manner evidenced by MTT assays and morphological changes. The apoptotic index measured by TUNEL increased correspondingly with the increased concentration of celecoxib and the reaction time. With 50 μmol/L celecoxib treatment for 24 h, the apoptotic index of HepG2, BEL-7402 and SMMC-7721 cells was 25.01±3.08%, 26.40±3.05%,and 30.60±2.89%, respectively. Western blotting analysis showed remarkable activation of caspase-9, caspase-3 and dephosphorylation of Akt （Thr^308）. Immunocytochemistry also showed the reduction of PCNA expression and phosphorylation Akt （Thr^308） after treatment with celecoxib. CONCLUSION： COX-2 mRNA and protein overexpression in HepG2, Bel-7402 and SMMC-7721 cell lines correlate with the increased cell growth rate. Celecoxib can inhibit proliferation and induce apoptosis of hepatoma cell strains in a dose- and time-dependent manner.
基金the grants of the Jilin Science&Technology Development Plan(Nos.20170101011JC,20200301037RQ and 20190103092JH)the Open Fund of Key Laboratory of Biotechnology and Bioresources Utilization(KF202004).
文摘Heat stress(HS)reaction can lead to serious physiological dysfunction associated with cardiovascular and various organ diseases.Ginsenoside Rg3(G-Rg3)is a representative component of ginseng rare saponin and can protect against multiple organs,also used as functional food to adjust the balance of the human body,but the therapeutic effect and molecular mechanism of G-Rg3 on male diseases under HS are underexplored.The aim of the present study,G-Rg3 was prepared through the efficient conversion of ginsenoside Rd and investigate the contribution of G-Rg3 to testicular injury induced exposure to HS.All mice were divided into four groups as follows:normal group,HS group,and HS+G-Rg3(5 and 10 mg/kg)groups.G-Rg3 was administered orally for 14 days,then exposed to a single scrotal heat treatment(43°C,18min)on the 7th day.After HS treatment,the morphology of testis and epididymis changes,and caused a significant loss of multinucleated giant cells,desquamation of germ cells in destructive seminiferous tubules,and degenerative Leydig cells,further destroying the production of sperm.After administration G-Rg3(5 and 10 mg/kg/day)for 2 weeks,the spermatogenic-related indexes of testosterone levels and superoxide dismutase(SOD)activity,glutathione(GSH)content significantly(p<0.01)increase compared with the HS group.Moreover,G-Rg3 treatment effectively ameliorated the production of malondialdehyde(MDA)(p<0.05 or p<0.01).Importantly,G-Rg3 exhibited the protective potential against HS-induced injury not only suppressing the protein levels of heme oxygenase-1(HO-1),hypoxia-inducible factor-1α(HIF-1α),and heat shock protein 70(HSP70)but also modulating the Bcl-2 family(p<0.01 or p<0.001)and activation of mitogen-activated protein kinase(MAPK)signaling pathways(p<0.01).For most of the parameters tested,the HS+G-Rg3(10 mg/kg)group exhibited potent effects compared with those exhibited by the low dose(5 mg/kg)group.In conclusion,the present study demonstrated that G-Rg3 exerted protective effects against HS-induced testicular dysfunction via inhibiting the MAPK-mediated oxidative stress and apoptosis in mice.
文摘Detection of circulating tumor-specific DNA, RNA or proteins can be difficult due to relative scarcity. Exosomes are extracellular vesicles, 30 - 150 nm in diameter derived from fusion of multivesicular bodies with the plasma membrane. They are composed of a lipid bilayer membrane and contain proteins, mRNA and miRNA. Exosomes are secreted by multiple cell types, including cancer cells. However, there is a relative lack of information concerning the contents of exosomes secreted by various tumor cell types. To examine exosomes in cancer, we collected blood plasma samples from patients with breast, ovarian, prostate, hepatic, gastric, colon, and pancreatic cancers. Exosomes were isolated from plasma and confirmed by AchE assay, transmission electron microscopy and expression of the CD63 exosomal marker. Expression of AFP, CA724, CA153, CEA, CA125, CA199 and PSA antigens were determined using an automated electro-chemiluminescence assay. Expression of the tumor-related chaperone protein, mortalin, was determined by Western blot analysis. Levels of exosome secretion were variable among the different tumor types. Both exosome levels and mortalin expression within tumor cell exosomes were higher than in healthy donors, except in pancreatic carcinoma, where exosomes were elevated but mortalin expression was not significantly different from healthy donors. Exosomes provide unique opportunities for the enrichment of tumor-specific materials and may be useful as biomarkers and possibly as tools of cancer therapies. Mortalin, which has been linked to cell proliferation and induction of epithelial-mesenchymal transition of cancer cells, may be useful as a prognostic biomarker and as a possible therapeutic target.
基金Project (No. 2011FZA7005) supported by the Fundamental Research Funds for the Central Universities of China
文摘Xiongdankaiming tablet (XDKMT), a well-known compound in traditional Chinese medicine, is widely used for the treatment of acute iridocyclitis and primary open-angle glaucoma. In this paper, accurate and reliable methods were developed for the identification of 20 constituents using high-performance liquid chromatography with photodiode array and electron spray ionization-mass spectrometry (HPLC-PDA/ESI-MSn ), and determination of nine of the constituents (chlorogenic acid, gentiopicroside, isochlorogenic acid B, diosmetin-7-O-β-D-glucopyranoside, apigenin, diosmetin, tauroursodeoxycholic acid, acacetin, and taurochenodeoxycholic acid) was developed using HPLC with ultraviolet absorption detector and evaporative light scattering detector (HPLC-UV/ELSD) for the first time. The best results were obtained on a Zorbax SB-C18 column with gradient elution using water (0.1% formic acid) (A) and methanol (0.1% formic acid) (B) at a flow rate of 0.7 ml/min. Tauroursodeoxycholic acid and taurochenodeoxycholic acid, owing to their low UV absorption, were detected by ELSD. The other seven compounds were analyzed by HPLC-UV with variable wavelengths. The calibration curves of all nine constituents showed good linear regression (R2 >0.9996) within the linearity ranges. The limits of detection and quantification were in the ranges of 0.0460-9.90 μg/ml and 0.115-24.8 μg/ml, respectively. The accuracy, in terms of recovery, varied from 95.3% to 104.9% with relative standard deviations (RSDs) less than 4.4%. Precision (with the intra- and inter-day variations less than 4.4%) was also suitable for its intended use. The developed method was successfully applied for the analysis of major components in XDKMT, which provides an appropriate method for the quality control of XDKMT.
基金Supported by the Research Project of Jiangxi Education Department(GJJ14289)the Research Project of Environmental Protection Department of Jiangxi Province(JXHBKJ2013-4)the Special Fund for Visiting Scholar of the Development Plan for Middle-aged and Young Teachers in Colleges of Jiangxi Province(No.GJGH[2014]15)~~
文摘[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterloggogenic type） in Jiangxi Province were chosen as test materials. The single and competitive adsorption behaviors of Cu and Pb in paddy soils were investigated with batch equilibrium method, and the environmental risk under coexistence of Cu and Pb in these soils was estimated with distribution coefficient. The results showed that under equal proportion, the adsorption affinity of Pb was greater than that of Cu in the two paddy soils, and the adsorption capacities in waterloggogenic paddy soil （WPS） were significantly higher than those in gley paddy soil （GTPS）, but the desorption capacities of Cu were greater than those of Pb in the two paddy soils, and the desorption capacities in GTPS were significantly higher than those in the WPS. The adsorption capacities of Cu and Pb ions under competitive condition were obviously lower than those in single system, while the desorption rates significantly increased. The potential environmental risk of Cu pollution was greater than that of Pb in paddy soils, and their environmental risk decreased with the increase of pH, but increased significantly under coexistence of lead and copper. [Conclusion] This research suggests that when Cu and Pb ions coexist in the paddy soils, compared with lead pollution, we should pay attention to the pollution of Cu.
文摘The conversion efficiency of stimulated Raman scattering （SRS） in CH4 is studied by using a single longitudinal mode second-harmonic Nd：YAG laser （532 nm, linewidth 0.003 cm^-1, pulse-width （FWHM） 6.5 ns）. Due to the heat release from vibrationally excited particles, SRS processes often suffer from the thermal defocusing effect （TDE）. In view of 6.5 ns laser pulse width is much shorter than the vibrational relaxation time of CH4 molecules, TDE can only affect the SRS processes afterwards. In the cases of low laser repetition, TDE will be not serious, because it will be removed by the thermal diffusion in Raman medium before the next pulse arrives. At the laser repetition rate 2 Hz, CH4 pressure 1.1 MPa and pump laser energy 95 mJ, the quantum conversion efficiency of backward first-Stokes （BS1） has attained 73%. This represents the highest first-stokes conversion efficiency in CH4. Furthermore, due to the relaxation oscillation, the BS1 pulses are narrowed to about 1.2 ns. As a result, the BS1 peak power turns out to be 2.7 times that of the pump. Its beam quality is also much better and is only slightly affected by TDE. This reason is that BS1 represents a wave-front-reversed replica of the pump beam, which can compensate the thermal distortions in Raman amplify process. Under the same conditions, but pump laser repetition rate as 10 Hz, the conversion efficiency of BS1 goes down to 36% due to TDE. From this study, we expect that a well-behaved 630 nm Raman laser may be designed by using a closed CH4/He circulating-cooling system, which may have some important applications.
基金financial support from the Ministry of Science and Technology of China(No.2018YFA0208704 and No.2016YFA0200602)the National Natural Science Foundation of China(No.21725305)financial support from the National Natural Science Foundation of China(No.21773237)。
文摘Mixed halide perovskites(MHPs)are a class of semiconductor materials with great promise for many optoelectronic applications due to their outstanding photophysical properties.Understanding and tailoring the photogenerated carrier dynamics is essential for further improvement of perovskite performance.Herein,we report a study about the carrier transport and interfacial charge transfer dynamics in Br-gradient MAPbI_(3-x)Br_(x) perovskite thin films prepared by surface ion-exchange method.Driven by the bandgap gradient in MAPbI_(3-x)Br_(x) films,the accelerated internal hole transport and enhanced interfacial extraction efficiency were both observed.Meanwhile,the interfacial electron transfer was also found to be evidently facilitated due to the surface modification during post-treatment.Our findings suggest the possibility of simultaneous acceleration of interfacial electron and hole transfer processes in halide perovskite films via surface post-treatment technique,which is of great importance in further improving the power conversion efficiency of perovskite solar cells.
基金Supported by the National Natural Science Foundation of China(31672452)the Natural Science Foundation of Yunnan Province(2014FA033)the Foundation of Yunnan Provincial Key Laboratory of Animal and Feed Science(DYCX2015001)
文摘To investigate the anaerobic fungal diversity in the rumen of gayals(Bos frontalis), Yunnan yellow cattle, yaks, and Tibetan yellow cattle, the ITS region of ruminal anaerobic fungi was sequenced. The anaerobic fungi found in four types of cattle could be divided into 16 groups(Neocallimastix, Anaeromyces, Orpinomyces, Caecomyces, Cyllamyces and unknown groups 1-11). There were 10 anaerobic fungal groups in the rumen of gayals, with three belonging to known genera(Orpinomyces, Neocallimastix, and Caecomyces), which accounted for 2.8% of sequences of gayals. There were fewer known anaerobic fungi in gayals than in Yunnan yellow cattle(Orpinomyces), yaks(Anaeromyces, Orpinomyces, and Cyllamyces) and Tibetan yellow cattle(Anaeromyces, Orpinomyces, Caecomyces, and Cyllamyces), accounting for 30.7%, 93.9%, and 35% of each of the relevant cattle species. The other seven unknown groups(NG1, NG4, NG6, NG7, NG9, NG10, and NG11) accounted for 91.6% of sequences from gayals, which was higher than Yunnan yellow cattle [69.3%(NG2, NG8 and NG9)], Tibetan yellow cattle [35%(NG4, NG5 and NG9)], and yaks [6.1%(NG3)]. Furthermore, NG1, NG6, NG7, NG10, and NG11 were only found in gayals,whereas NG3 and NG5 were found only in Tibetan yellow cattle and yak, respectively. Piromyces was not found in any of the four types of cattle. The anaerobic fungi abundance in the rumen of gayals was significantly higher than that of the other three types of cattle. The ruminal anaerobic fungi of gayals might have an important role in cellulose degradation, resulting in the ability of this species to successfully graze coarser fodder.
基金supported by Jiangsu Province Natural Science Foundation for Distinguished Young Scholars(BK20190035)Jiangsu Government Scholarship for Overseas Studies(JS-2019-053)+6 种基金Key Research&Development plan of Jiangsu Province(BE2019001)the National Natural Science Foundation of China(2217080044 and 22008119)the Natural Science Foundation of Jiangsu Province(BK20202002)the National Key Research and Development Program of China(2021YFC2101204)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_14R28)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture.
文摘Adenylate cyclase(AC)is the key enzyme that catalyzes the formation of cAMP from ATP.In this study,we discovered two novel class Ⅲ ACs with a halophilic property from Thermobifida halotolerans DSM 44931(ThAC)and Haloactinopolyspora alba DSM 45211(HaAC),respectively.The recombinant ThAC and HaAC were expressed in Escherichia coli with molecular weights of 36.1 and 36.0 kDa respectively.The presence of 2500 and 2200 mmolL^(-1)1 NaCl significantly enhanced the enzyme activities of ThAC and HaAC,with 22-fold and 7.4-fold higher activities compared to those without NaCl,respectively.Several divalent metal ions were found to activate the recombinant ACs to different extents,and the optimal metal ion was Mg^(2+)for both ThAC and HaAC with concentrations of 80 mmol·L^(-1) and 40 mmol·L^(-1) respectively.Purified ThAC and HaAC had the optimal specific activities((4.59±0.35)×10^(4) and(7.76±0.52)×10^(4) U·mg^(-1))and catalytic efficiency(4.47 and 5.30 L·mmol^(-1)·s^(-1))at 45℃ and 40℃ respectively,while the optimum pH of both two recombinant ACs was 10.0.This is the first report of the halophilic Class III ACs,which could make new contributions to explore and study ACs for further associated investigations.
基金supported by the NSFC(21703241)the Youth Innovation Promotion Association CAS(2019188)the DICP I201913。
文摘Organolead halide perovskite solar cells have attracted extensive interests in recent years. Thanks to innovations in materials process and technology, the power conversion efficiency (PCE) of perovskites-based solar cells increases from 3.8% to 25.2%[1–4].In evaluating the quality of perovskite materials, a few key photophysical properties such as the lifetime, mobility and diffusion length of photogenerated carriers are usually measured.
基金supported by the Open Fund of the State Key Laboratory of Molecular Reaction Dynamics at Dalian Institute of Chemical Physics,Chinese Academy of Sciences(No.SKLMRD-K202108)。
文摘Photophysical processes occurring within organic semiconductors is important for designing and fabricating organic solar cells.Copper phthalocyanine(CuPc)is a typical electron acceptor.In this work,the triplet exciton lifetime is prolonged by altering the molecular stacking pattern of the CuPc film.For CuPc thin films,the excited state decays are mainly determined by the triplet-triplet annihilation process.The ultrafast transient absorption measurements indicate that the primary annihilation mechanism is one-dimensional exciton diffusion collision destruction.The decay kinetics show a clearly time-dependent annihilation rate constant withγ∝t^(-1/2).Annihilation rate constants are determined to beγ0=(2.87±0.02)×10^(-20)cm^(3)·s^(-1/2)and(1.42±0.02)×10^(-20)cm^(3)·s^(-1/2)for upright and lyingdown configurations,respectively.Compared to the CuPc thin film with an upright configuration,the thin film with a lying-down configuration shows longer exciton lifetime and higher absorbance,which are beneficial to organic solar cells.The results in this work have important implications on the design and mechanistic understanding of organic optoelectronic devices.
基金supported by the Natural Science Foundation of Liaoning Province(No.20170540086)the Open Fund of the State Key Laboratory of Molecular Reaction Dynamics in Dalian Institute of Chemical Physics,Chinese Academy of Sciences(SKLMRD-K202107,K202216)。
文摘The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskite films.It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization.Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride(p-g-C_(3)N_(4))was successfully synthesized and doped into perovskite layer of carbon-based PSCs.The addition of p-g-C_(3)N_(4)into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide(MAPb I3)crystal for obtaining flat perovskite surface with larger grain size,but also reduces intrinsic defects of perovskite layer.It is found that thep-g-C_(3)N_(4) locates at the perovskite core,and the active groups-NH_(2)/NH_(3)and NH have a hydrogen bond strengthening,which effectively passivates electron traps and enhances the crystal quality of perovskite.As a result,a higher power conversion efficiency of 6.61% is achieved,compared with that doped with g-C_(3)N_(4)(5.93%)and undoped one(4.48%).This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.
基金supported by the Carbon Peak&Carbon Neutralization Innovation Project of Jiangsu Province (BE2022309)Natural Science Foundation of China (32161143028,32061143034)the National Modern Agricultural Industry Technology System Guangxi Dairy Buffalo Innovation Team Project (nycytxgxcxtd-2021-21)。
文摘Background Lignocellulose biomass is the most abundant and renewable material in nature.The objectives of this study were to characterize two endoglucanases Trep Cel3 and Trep Cel4,and determine the effect of the combination of them(1.2 mg Trep Cel3,0.8 mg Trep Cel4)on in vitro rumen fermentation characteristics.In this study,three nature lignocellulosic substrates(rice straw,RS;wheat straw,WS;leymus chinensis,LC)were evaluated for their in vitro digestibility,gas,NH3-N and volatile fatty acid(VFA)production,and microbial protein(MCP)synthesis by adding enzymatic combination.Methods Two endoglucanases’genes were successfully expressed in Escherichia coli(E.coli)BL21(DE3),and enzymatic characteristics were further characterized.The combination of Trep Cel3 and Trep Cel4 was incubated with lignocellulosic substrates to evaluate its hydrolysis ability.Results The maximum enzymatic activity of Trep Cel3 was determined at p H 5.0 and 40℃,while Trep Cel4 was at p H 6.0 and 50℃.They were stable over the temperature range of 30 to 60℃,and active within the p H range of 4.0 to 9.0.The Trep Cel3 and Trep Cel4 had the highest activity in lichenan 436.9±8.30 and 377.6±6.80 U/mg,respectively.The combination of Trep Cel3 and Trep Cel4 exhibited the highest efficiency at the ratio of 60:40.Compared to maximum hydrolysis of Trep Cel3 or Trep Cel4 separately,this combination was shown to have a superior ability to maximize the saccharification yield from lignocellulosic substrates up to 188.4%for RS,236.7%for wheat straw WS,222.4%for LC and 131.1%for sugar beet pulp(SBP).Supplemental this combination enhanced the dry matter digestion(DMD),gas,NH3-N and VFA production,and MCP synthesis during in vitro rumen fermentation.Conclusions The Trep Cel3 and Trep Cel4 exhibited the synergistic relationship(60:40)and significantly increased the saccharification yield of lignocellulosic substrates.The combination of them stimulated in vitro rumen fermentation of lignocellulosic substrates.This combination has the potential to be a feed additive to improve agricultural residues utilization in ruminants.If possible,in the future,experiments in vivo should be carried out to fully evaluate its effect.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11574116, 11534004, and 10704028).
文摘The ionization processes of NH3 molecule are studied by photoelectron velocity map imaging technique in a linearly polarized 400-nm femtosecond laser field. The two-dimensional photoelectron images from ammonia molecules under different laser intensities are obtained. In the slow electron region, the values of kinetic energy of photoelectrons corresponding to peaks 1, 2, 3, and 4 are 0.27, 0.86, 1.16, and 1.6 eV, respectively. With both the kinetic energy and angular distribution of photoelectrons from NH3 molecules, we can confirm that the two-photon excited intermediate Rydberg state is A^1 A2" (v2'=3) state for photoelectron peaks 2, 3, 4, and the three peaks are marked as 1223 (2 + 2), 1123 (2 + 2), and 1023 (2 + 2) multi-photon processes, respectively. Then, peak 1 is found by adding a hexapole between the source chamber and the detection chamber to realize the rotational state selection and beam focusing. Peak 1 is labeled as the 1323 (3 + 1) multi-photon process through the intermediate Rydberg state E^1A1'. The phenomena of channel switching are found in the slow electron kinetic energy distributions. Our calculations and experimental results indicate that the stretching vibrational mode of ammonia molecules varies with channels, while the umbrella vibration does not. In addition, we consider and discuss the ac-Stark effect in a strong laser field. Peaks 5 and 6 are marked as (2 + 2 + 1) and (2 + 2 + 2) above threshold ionization processes in the fast electron region.
基金supported by the National Natural Science Foundation of China(Grant Nos.11574116,11534004,11704147,and 10704028)。
文摘The above-threshold ionization process of ammonia molecules induced by a femtosecond laser field at 800 nm is studied in the intensity range from 1.6×10^(13) to 5.7×10^(13)W/cm^(2).Channel switching under different laser intensities is observed and identified in the photoelectron kinetic energy spectra of ammonia.Based on the photoelectron kinetic energy distributions and the photoelectron angular distributions,the characteristic peaks observed are exclusively assigned to the multiphoton resonance through certain intermediate states,followed by multiphoton above-threshold ionization.
文摘BACKGROUND The development of laparoscopic technology has provided a new choice for surgery of gastric cancer(GC),but the advantages and disadvantages of laparoscopic total gastrectomy(LTG)and laparoscopic-assisted total gastrectomy(LATG)in treatment effect and safety are still controversial.The purpose of this study is to compare the efficacy and safety of the two methods in the treatment of GC,and to provide a basis for clinical decision-making.AIM To compare the efficacy of totally LTG(TLTG)and LATG in the context of radical gastrectomy for GC.Additionally,we investigated the safety and feasibility of the total laparoscopic esophagojejunostomy technique.METHODS Literature on comparative studies of the above two surgical methods for GC(TLTG group and LATG group)published before September 2022 were searched in the PubMed,Web of Science,Wanfang Database,CNKI,and other Chinese and English databases.In addition,the following search keywords were used:Gastric cancer,total gastrectomy,total laparoscopy,laparoscopy-assisted,esophagojejunal anastomosis,gastric/stomach cancer,total gastrectomy,totally/completely laparoscopic,laparoscopic assisted/laparoscopy assisted/laparoscopically assisted,and esophagojejunostomy/esophagojejunal anastomosis.Review Manager 5.3 software was used for the meta-analysis after two researchers independently screened the literature,extracted the data,and evaluated the risk of bias in the included studies.RESULTS After layer-by-layer screening,258 pieces of literature were recovered,and 11 of those pieces were eventually included.This resulted in a sample size of 2421 instances,with 1115 cases falling into the TLTG group and 1306 cases into the LATG group.Age or sex differences between the two groups were not statistically significant,according to the meta-analysis,however the average body mass index of the TLTG group was considerably higher than that of the LATG group(P=0.01).Compared with those in the LATG group,the incision length in the TLTG group was significantly shorter(P<0.001),the amount of intraoperative blood loss was significantly lower(P=0.003),the number of lymph nodes removed was significantly greater(P=0.04),and the time of first postoperative feeding and postoperative hospitalization were also significantly shorter(P=0.03 and 0.02,respectively).There were no significant differences in tumor size,length of proximal incisal margin,total operation time,anastomotic time,postoperative pain score,postoperative anal exhaust time,postoperative anastomosis-related complications(including anastomotic fistula,anastomotic stenosis,and anastomotic hemorrhage),or overall postoperative complication rate(P>0.05).CONCLUSION TLTG and esophagojejunostomy are safe and feasible.Compared with LATG,TLTG has the advantages of less trauma,less bleeding,easier access to lymph nodes,and faster postoperative recovery,and TLTG is also suitable for obese patients.
