Photoreceptor cell degeneration leads to blindness, for which there is currently no effective treatment. Our previous studies have shown that Lycium barbarum(L. barbarum) polysaccharide(LBP) protects degenerated photo...Photoreceptor cell degeneration leads to blindness, for which there is currently no effective treatment. Our previous studies have shown that Lycium barbarum(L. barbarum) polysaccharide(LBP) protects degenerated photoreceptors in rd1, a transgenic mouse model of retinitis pigmentosa. L. barbarum glycopeptide(Lb GP) is an immunoreactive glycoprotein extracted from LBP. In this study, we investigated the potential protective effect of Lb GP on a chemically induced photoreceptor-degenerative mouse model. Wild-type mice received the following: oral administration of Lb GP as a protective pre-treatment on days 1–7;intraperitoneal administration of 40 mg/kg N-methylN-nitrosourea to induce photoreceptor injury on day 7;and continuation of orally administered Lb GP on days 8–14. Treatment with Lb GP increased photoreceptor survival and improved the structure of photoreceptors, retinal photoresponse, and visual behaviors of mice with photoreceptor degeneration. Lb GP was also found to partially inhibit the activation of microglia in N-methyl-N-nitrosourea-injured retinas and significantly decreased the expression of two pro-inflammatory cytokines. In conclusion, Lb GP effectively slowed the rate of photoreceptor degeneration in N-methyl-N-nitrosourea-injured mice, possibly through an anti-inflammatory mechanism, and has potential as a candidate drug for the clinical treatment of photoreceptor degeneration.展开更多
Objective:To provide real-world evidence for the application of first-line dacomitinib treatment for epidermal growth factor receptor(EGFR)21L858R mutant non-small cell lung cancer(NSCLC)patients in China and to explo...Objective:To provide real-world evidence for the application of first-line dacomitinib treatment for epidermal growth factor receptor(EGFR)21L858R mutant non-small cell lung cancer(NSCLC)patients in China and to explore the factors influencing the efficacy and safety.Methods:A longitudinal,consecutive case-series,multicenter study with mixed prospective and retrospective data was conducted.The primary endpoint was progression-free survival(PFS),and the secondary endpoints included duration of treatment(DOT),overall survival(OS),objective response rate(ORR),disease control rate(DCR)and safety.Results:A total of 155 EGFR 21L858R mutant patients treated with first-line dacomitinib were included.The median follow-up time for these patients was 20.4 months.Among 134 patients with evaluable lesions,the ORR was 70.9%and the DCR was 96.3%.The median PFS was 16.3[95%confidence interval(95%CI),13.7−18.9]months.Multivariate Cox regression analysis suggested that the baseline brain metastasis(BM)status[with vs.without BM:hazard ratio(HR),1.331;95%CI,0.720−2.458;P=0.361]and initial doses(45 mg vs.30 mg:HR,0.837;95%CI,0.427−1.641;P=0.604)did not significantly affect the median PFS.The median DOT was 21.0(95%CI,17.5−24.6)months and the median OS was not reached.Genetic tests were performed in 64 patients after progression,among whom 29(45.3%)patients developed the EGFR 20T790M mutation.In addition,among the 46 patients who discontinued dacomitinib treatment after progression,31(67.4%)patients received subsequent third-generation EGFR-tyrosine kinase inhibitors.The most common grade 3−4 adverse events were rash(10.4%),diarrhea(9.1%),stomatitis(7.1%)and paronychia(4.5%).The incidence of grade 3−4 rash was significantly higher in the 45 mg group than that in the 30 mg group(21.9%vs.7.5%,P=0.042).Conclusions:First-line dacomitinib treatment demonstrated promising efficacy and tolerable adverse events among EGFR 21L858R mutant NSCLC patients in China.展开更多
As an important wide-bandgap semiconductor,gallium nitride(GaN)has attracted considerable attention.This paper describes the use of confocal Raman spectroscopy to characterize undoped GaN,n-type GaN,and p-type GaN thr...As an important wide-bandgap semiconductor,gallium nitride(GaN)has attracted considerable attention.This paper describes the use of confocal Raman spectroscopy to characterize undoped GaN,n-type GaN,and p-type GaN through depth profiling using 405-,532-,and 638-nm wavelength lasers.The Raman signal intensity of the sapphire substrate at different focal depths is studied to analyze the depth resolution.Based on the shift of the E2 H mode of the GaN epitaxial layer,the interfacial stress for different types of GaN is characterized and calculated.The results show that the maximum interfacial stress appears approximately at the junction of the GaN and the sapphire substrate.Local interfacial stress analysis between the GaN epitaxial layer and the substrate will be very helpful in furthering the applications of GaN devices.展开更多
Silicon-vacancy(VSi)centers in silicon carbide(SiC)are expected to serve as solid qubits,which can be used in quantum computing and sensing.As a new controllable color center fabrication method,femtosecond(fs)laserwri...Silicon-vacancy(VSi)centers in silicon carbide(SiC)are expected to serve as solid qubits,which can be used in quantum computing and sensing.As a new controllable color center fabrication method,femtosecond(fs)laserwriting has been gradually applied in the preparation of VSi in SiC.In this study,4H-SiCwas directlywritten by an fs laser and characterized at 293 K by atomic force microscopy,confocal photoluminescence(PL),and Raman spectroscopy.PL signals of VSi were found and analyzed using 785 nm laser excitation by means of depth profiling and two-dimensional mapping.The influence of machining parameters on the VSi formation was analyzed,and the three-dimensional distribution of VSi defects in the fs laser writing of 4H-SiC was established.展开更多
All organisms must transmit genetic information to offspring through cell division, and mitotic spindle participates in the process. Spindle dynamics through depolymerization or polymerization of microtubules generate...All organisms must transmit genetic information to offspring through cell division, and mitotic spindle participates in the process. Spindle dynamics through depolymerization or polymerization of microtubules generates the driving force required for chromosome movements in mitosis. To date, studies have shown that microtubule arrays control the directions of cell division and diverse microtubule-associated proteins regulate cell division. But a clear picture of how microtubules and microtubule-associated proteins modulate cell division remains unknown. Depletion of end-binding protein 1 by RNA-mediated inhibition shows that one of the microtubule-associated proteins, end-binding protein 1, plays a crucial role in mitotic spindle formation and promotes microtubule dynamics and is needed for the proper segregation of mitotic chromosomes during anaphase in Drosophila cells. Here, we review the properties of end-binding protein 1 and the roles of end-binding protein 1 in regulating microtubule behavior and in cell cycle.展开更多
In solids,the reservation of symmetries defines the types of topological invariants that classify various topological quantum materials[1–3].Among them,the time-reversal symmetry(TRS)is the most fundamental,which pla...In solids,the reservation of symmetries defines the types of topological invariants that classify various topological quantum materials[1–3].Among them,the time-reversal symmetry(TRS)is the most fundamental,which plays key role in topological helical edge or surface states.Nevertheless,breaking TRS in topological materials typically gives rise to unexpected exotic states,such as magnetic Weyl semimetals,quantum anomalous Hall insulators,and axion insulators.展开更多
Color centers in silicon carbide(SiC)are promising candidates for quantum technologies.However,the richness of the polytype and defect configuration of SiC makes the accurate control of the types and position of defec...Color centers in silicon carbide(SiC)are promising candidates for quantum technologies.However,the richness of the polytype and defect configuration of SiC makes the accurate control of the types and position of defects in SiC still challenging.In this study,helium ion-implanted 4H-SiC was characterized by atomic force microscopy(AFM),confocal photoluminescence(PL),and confocal Raman spectroscopy at room temperature.PL signals of silicon vacancy were found and analyzed using 638-nm and 785-nm laser excitation by means of depth profiling and SWIFT mapping.Lattice defects(C-C bond)were detected by continuous laser excitation at 532 nm and 638 nm,respectively.PL/Raman depth profiling was helpful in revealing the three-dimensional distribution of produced defects.Differences in the depth profiling results and SRIM simulation results were explained by considering the depth resolution of the confocal measurement setup,helium bubbles,as well as swelling.展开更多
We report the coordination assembly of the ferrocene-diphenylalanine(Fc-FF)with divalent copper ions(Cu^(2+))into metalpeptide assemblies(MPAs)with hierarchical spiral architectures.The MPA particles are composed of h...We report the coordination assembly of the ferrocene-diphenylalanine(Fc-FF)with divalent copper ions(Cu^(2+))into metalpeptide assemblies(MPAs)with hierarchical spiral architectures.The MPA particles are composed of helically organized nanofibers which can be correlated to the logarithmic spirals.The MPAs are hierarchically porous with abundant Fc and Cu2+active sites and show much higher catalytic activity than natural laccase toward the decolorization reaction.Moreover,a series of hierarchical structures of the MPAs can be synthesized by controlling the temperature and enantiomeric excess(ee).The peptide enantiomers with higher ee values will self-assemble into highly complex and ordered structures,which show higher surface area and porosity and thus enhanced catalytic activity compared with those assembled by peptides with lower ee values.The results provide new insights into the vital role of chirality in directing the self-assembly of biomolecules into highly ordered complex functional structures.展开更多
The direct conversion of ethanol to 1,1-diethoxyethane(DEE)through one-pot dehydrogenation-acetalization has attracted broad interest from both academia and industry.Based on thermodynamics,the oxidative dehydrogenati...The direct conversion of ethanol to 1,1-diethoxyethane(DEE)through one-pot dehydrogenation-acetalization has attracted broad interest from both academia and industry.Based on thermodynamics,the oxidative dehydrogenation of alcohol to acetaldehyde requires high temperature to activate oxygen to realize the C-H cleavage,while the acetalization of acetaldehyde with ethanol is exothermic reversible reaction favorable at low temperature.The mismatching of the reaction condition for the two consecutive steps makes it a great challenge to achieve both high ethanol conversion and high DEE selectivity.This work reports a highly efficient bi-functional catalysis by Bi/BiCeO_(x)for one-pot oxidative dehydrogenation-acetalization route from ethanol to DEE under 150℃and ambient pressure,affording a selectivity of 98.5%±0.5%to DEE at an ethanol conversion of 87.0%±1.0%.An efficient tandem catalysis has been achieved on the interfacial Bi^(δ)+-Ov-Ce^(III)sites in Bi/BiCeO_(x)established by strong metal-support interaction,in which Biδ+-Ov-sites contribute to the oxidative dehydrogenation of ethanol at mild temperature,and-Ov-CeIII sites to the subsequent acetalization between the generated acetaldehyde and ethanol.展开更多
Background Multimodal techniques-assisted resection of glioma under general anesthesia(GA)has been shown to achieve similar clinical outcomes as awake craniotomy(AC)in some studies.In this study,we aim to validate the...Background Multimodal techniques-assisted resection of glioma under general anesthesia(GA)has been shown to achieve similar clinical outcomes as awake craniotomy(AC)in some studies.In this study,we aim to validate the use of multimodal techniques can achieve the maximal safe resection of high-grade glioma involving language areas(HGILAs)under GA.Methods HGILAs cases were reviewed and collected between January 2009 and December 2020 in our center.Patients were separated into multimodal group(using neuronavigation,intraoperative MRI combined with direct electrical stimulation[DES]and neuromonitoring[IONM])and conventional group(neuronavigation alone)and clinical outcomes were compared between groups.Studies of HGILAs were reviewed systematically and the meta-analysis results of previous(GA or AC)studies were compared with our results.Results Finally,there were 263 patients in multimodal group and 137 patients in conventional group.Compared to the conventional group,the multimodal group achieved the higher median EOR(100%versus 94.32%,P<0.001)and rate of gross total resection(GTR)(73.8%versus 36.5%,P<0.001)and the lower incidence of permanent language deficit(PLD)(9.5%versus 19.7%,P=0.004).The multimodal group achieved the longer median PFS(16.8 versus 10.3 months,P<0.001)and OS(23.7 versus 15.7 months,P<0.001)than the conventional group.The multimodal group achieved a higher rate of GTR than the cohorts in previous multimodal studies under GA and AC(73.8%versus 55.7%[95%CI 32.0-79.3%]versus 53.4%[35.5-71.2%]).The multimodal group had a lower incidence of PLD than the cohorts in previous multimodal studies under GA(9.5%versus 14.0%[5.8-22.1%])and our incidence of PLD was a little higher than that of previous multimodal studies under AC(9.5%versus 7.5%[3.7-11.2%]).Our multimodal group also achieved a relative longer survival than previous studies.Conclusions Surgery assisted by multimodal techniques can achieve maximal safe resection for HGILAs under GA.Further prospective studies are needed to compare GA with AC for HGILAs.展开更多
Emerging lines of evidence have shown that the production of the covalently closed single-stranded circular RNAs is not splicing errors,but rather a regulated process with distinct biogenesis and turnover.Circular RNA...Emerging lines of evidence have shown that the production of the covalently closed single-stranded circular RNAs is not splicing errors,but rather a regulated process with distinct biogenesis and turnover.Circular RNAs are expressed in a cell type-and tissue-specific manner and often localize to specific subcellular regions or organelles for functions.The dysregulation of circular RNAs from birth to death is linked to the pathogenesis and progression of diverse diseases.This review outlines how aberrant circular RNA biogenesis,subcellular location,and degradation are linked to disease progression,focusing on metaflammation and cancers.We also discuss potential therapeutic strategies and obstacles in targeting such disease-related circular RNAs.展开更多
After a major outage,mobile emergency resources(MERs)can be dispatched via the transportation system(TS)for service restoration to critical loads in the power distribution system(PDS).In this case study,the efficiency...After a major outage,mobile emergency resources(MERs)can be dispatched via the transportation system(TS)for service restoration to critical loads in the power distribution system(PDS).In this case study,the efficiency of service restoration in the PDS is associated with the traffic efficiency of the TS,and vice versa,because the PDS and TS are mutually coupled through traffic lights and MERs.This paper proposes a service restoration method considering interdependency between the PDS and TS,which is formulated as a mixed-integer linear program(MILP).The objective includes maximizing the efficiency of both PDS restoration and TS.By solving the MILP,the dynamic load restoration and MER dispatch strategies can be obtained.For the PDS,the availability of MERs,including mobile sources and repair crews,relates to their dispatch in the TS,and their relationship is formulated as mathematical models.For the TS,the dynamic traffic flow is modeled using the cell transmission model and the effect of traffic lights is considered.Case studies validate the effectiveness of the proposed method.展开更多
Vascular smooth muscle cell (vSMC) is highly plastic as its phenotype can change in response to mechanical cues inherent to the extracellular matrix (ECM). VSMC may be activated from its quiescent contractile phenotyp...Vascular smooth muscle cell (vSMC) is highly plastic as its phenotype can change in response to mechanical cues inherent to the extracellular matrix (ECM). VSMC may be activated from its quiescent contractile phenotype to a proinflammatory phenotype, whereby the cell secretes chemotactic and inflammatory cytokines, e.g. MCP1 and IL6, to functionally regulate monocyte and macrophage infiltration during the development of various vascular diseases including arteriosclerosis. Here, by culturing vSMCs on polyacrylamide (PA) substrates with variable elastic moduli, we discovered a role of discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that binds collagens, in mediating the mechanical regulation of vSMC gene expression, phenotype, and proinflammatory responses. We found that ECM stiffness induced DDR1 phosphorylation, oligomerization, and endocytosis to repress the expression of DNA methyltransferase 1 (DNMT1), very likely in a collagen-independent manner. The DDR1-to-DNMT1 signaling was sequentially mediated by the extracellular signal-regulated kinases (ERKs) and p53 pathways. ECM stiffness primed vSMC to a proinflammatory phenotype and this regulation was diminished by DDR1 inhibition. In agreement with the in vitro findings, increased DDR1 phosphorylation was observed in human arterial stiffening. DDR1 inhibition in mouse attenuated the acute injury or adenine diet-induced vascular stiffening and inflammation. Furthermore, mouse vasculature with SMC-specific deletion of Dnmt1 exhibited proinflammatory and stiffening phenotypes. Our study demonstrates a role of SMC DDR1 in perceiving the mechanical microenvironments and down-regulating expression of DNMT1 to result in vascular pathologies and has potential implications for optimization of engineering artificial vascular grafts and vascular networks.展开更多
O-linked N-acetyl-glucosamine glycosylation(O-GlcNAcylation)of intracellular proteins is a dynamic process broadly implicated in age-related disease,yet it remains uncharacterized whether and how O-GlcNAcylation contr...O-linked N-acetyl-glucosamine glycosylation(O-GlcNAcylation)of intracellular proteins is a dynamic process broadly implicated in age-related disease,yet it remains uncharacterized whether and how O-GlcNAcylation contributes to the natural aging process.O-GlcNAc transferase(OGT)and the opposing enzyme O-GlcNAcase(OGA)control this nutrient-sensing protein modification in cells.Here,we show that global O-GlcNAc levels are increased in multiple tissues of aged mice.In aged liver,carbamoyl phosphate synthetase 1(CPS1)is among the most heavilyO-GlcNAcylated proteins.CPS1O-GlcNAcylation is reversed by calorie restriction and is sensitive to genetic and pharmacological manipulations of theO-GlcNAc pathway.High glucose stimulates CPS1O-GlcNAcylation and inhibits CPS1 activity.Liver-specific deletion of OGT potentiates CPS1 activity and renders CPS1 irresponsive to further stimulation by a prolonged fasting.Our results identify CPS1 O-GlcNAcylation as a key nutrient-sensing regulatory step in the urea cycle during aging and dietary restriction,implying a role for mitochondrial O-GlcNAcylation in nutritional regulation of longevity.展开更多
Scutellarin related drugs have superior therapeutic effects on cerebrovascular and cardiovascular diseases.Here,an optimal biosynthetic pathway for scutellarin was constructed in Yarrowia lipolytica platform due to it...Scutellarin related drugs have superior therapeutic effects on cerebrovascular and cardiovascular diseases.Here,an optimal biosynthetic pathway for scutellarin was constructed in Yarrowia lipolytica platform due to its excellent metabolic potential.By integrating multi-copies of core genes from different species,the production of scutellarin was increased from 15.11 mg/L to 94.79 mg/L and the ratio of scutellarin to the main by-product was improved about 110-fold in flask condition.Finally,the production of scutellarin was improved 23-fold and reached to 346 mg/L in fed-batch bioreactor,which was the highest reported titer for de novo production of scutellarin in microbes.Our results represent a solid basis for further production of natural products on unconventional yeasts and have a potential of industrial implementation.展开更多
Vermicomposting is an efficient and environmentally friendly technology to dispose of agricultural organic residues.The efficiency of organic residue decomposition during vermicomposting is directly affected by the bi...Vermicomposting is an efficient and environmentally friendly technology to dispose of agricultural organic residues.The efficiency of organic residue decomposition during vermicomposting is directly affected by the biomass and population structure of earthworms.In this study,we investigated how the earthworm biomass and population structure responded to changes in the physicochemical properties of six types of organic residue(cattle dung,herbal waste,rice straw,soybean straw,garden waste,and tea residues)during vermicomposting.Each type of organic residues was placed in a pot with earthworms Eisenia fetida,and the physicochemical properties of the organic residues and earthworm growth dynamics were recorded at 0,30,60,and 90 d of vermicomposting.The biomass and population structure of earthworms were stable or increased in rice straw,garden waste,and cattle dung within 60 d of vermicomposting,whereas in tea residues and herb waste,very little earthworm activity(3 adults and 2 cocoons)was recorded on day 30.Among the physicochemical parameters,the substrate C/N ratio was negatively correlated with earthworm growth dynamics.Decomposing organic residues showed higher NH_(4)^(+)-N and NH_(3)^(-)-N concentrations but a lower total organic carbon content,which negatively affected earthworm growth and reproduction.We recommend that chemical properties of vermicomposting systems should be monitored regularly.At the threshold levels of decomposing organic residue NH_(4)^(+)-N and NH_(3)^(-)-N concentrations,earthworms should be removed and the vermicompost can be harvested.Small-and large-scale farmers thus need to monitor the physicochemical properties of vermicompost to sustain active earthworm populations.展开更多
Fibonacci number spiral patterns can be found in nature,particularly in plants,such as the sunflowers and phyllotaxis.Here,we demonstrated this pattern can be reproduced spontaneously within self-assembling peptide na...Fibonacci number spiral patterns can be found in nature,particularly in plants,such as the sunflowers and phyllotaxis.Here,we demonstrated this pattern can be reproduced spontaneously within self-assembling peptide nanofibril films.By high-temperature water vapor annealing of an amorphous film containing both peptide and cationic diamines,well-defined amyloid-like nanofibrils can be assembled spontaneously,during which the nanofibrils will hierarchically stack with each other following the Fibonacci number patterns.The formation of the patterns is a selftemplated process,which involves stepwise chiral amplification from the molecular scale to the nano-and micro-scales.Moreover,by controlling the diameter,length,and handedness of the nanofibrils,various complex hierarchical structures could be formed,including vertically aligned nanoarray,mesoscale helical bundles,Fibonacci number spirals,and then helical toroids.The results provide new insights into the chiral self-assembly of simple biological molecules,which can advance their applications in optics and templated synthesis.展开更多
基金supported by Guangzhou Key Projects of Brain Science and Brain-Like Intelligence Technology,No.20200730009 (to YX)the National Natural Science Foundation of China,No.82074169 (to XM)+2 种基金the Guangdong Basic and Applied Basic Research Foundation,No.2021A1515012473 (to XM)Project of Administration of Traditional Chinese Medicine of Guangdong Province,No.20202045 (to XM)Aier Eye Hospital Group,No.AF2019001 (to ST,KFS,YX,XM)。
文摘Photoreceptor cell degeneration leads to blindness, for which there is currently no effective treatment. Our previous studies have shown that Lycium barbarum(L. barbarum) polysaccharide(LBP) protects degenerated photoreceptors in rd1, a transgenic mouse model of retinitis pigmentosa. L. barbarum glycopeptide(Lb GP) is an immunoreactive glycoprotein extracted from LBP. In this study, we investigated the potential protective effect of Lb GP on a chemically induced photoreceptor-degenerative mouse model. Wild-type mice received the following: oral administration of Lb GP as a protective pre-treatment on days 1–7;intraperitoneal administration of 40 mg/kg N-methylN-nitrosourea to induce photoreceptor injury on day 7;and continuation of orally administered Lb GP on days 8–14. Treatment with Lb GP increased photoreceptor survival and improved the structure of photoreceptors, retinal photoresponse, and visual behaviors of mice with photoreceptor degeneration. Lb GP was also found to partially inhibit the activation of microglia in N-methyl-N-nitrosourea-injured retinas and significantly decreased the expression of two pro-inflammatory cytokines. In conclusion, Lb GP effectively slowed the rate of photoreceptor degeneration in N-methyl-N-nitrosourea-injured mice, possibly through an anti-inflammatory mechanism, and has potential as a candidate drug for the clinical treatment of photoreceptor degeneration.
文摘Objective:To provide real-world evidence for the application of first-line dacomitinib treatment for epidermal growth factor receptor(EGFR)21L858R mutant non-small cell lung cancer(NSCLC)patients in China and to explore the factors influencing the efficacy and safety.Methods:A longitudinal,consecutive case-series,multicenter study with mixed prospective and retrospective data was conducted.The primary endpoint was progression-free survival(PFS),and the secondary endpoints included duration of treatment(DOT),overall survival(OS),objective response rate(ORR),disease control rate(DCR)and safety.Results:A total of 155 EGFR 21L858R mutant patients treated with first-line dacomitinib were included.The median follow-up time for these patients was 20.4 months.Among 134 patients with evaluable lesions,the ORR was 70.9%and the DCR was 96.3%.The median PFS was 16.3[95%confidence interval(95%CI),13.7−18.9]months.Multivariate Cox regression analysis suggested that the baseline brain metastasis(BM)status[with vs.without BM:hazard ratio(HR),1.331;95%CI,0.720−2.458;P=0.361]and initial doses(45 mg vs.30 mg:HR,0.837;95%CI,0.427−1.641;P=0.604)did not significantly affect the median PFS.The median DOT was 21.0(95%CI,17.5−24.6)months and the median OS was not reached.Genetic tests were performed in 64 patients after progression,among whom 29(45.3%)patients developed the EGFR 20T790M mutation.In addition,among the 46 patients who discontinued dacomitinib treatment after progression,31(67.4%)patients received subsequent third-generation EGFR-tyrosine kinase inhibitors.The most common grade 3−4 adverse events were rash(10.4%),diarrhea(9.1%),stomatitis(7.1%)and paronychia(4.5%).The incidence of grade 3−4 rash was significantly higher in the 45 mg group than that in the 30 mg group(21.9%vs.7.5%,P=0.042).Conclusions:First-line dacomitinib treatment demonstrated promising efficacy and tolerable adverse events among EGFR 21L858R mutant NSCLC patients in China.
基金the National Natural Science Foundation of China(Grant Nos.51575389 and 51761135106)the National Key Research and Development Program of China(Grant No.2016YFB1102203)+1 种基金the State Key Laboratory of Precision Measuring Technology and Instruments(Pilt1705)the‘111’Project of the State Administration of Foreign Experts Affairs and the Ministry of Education of China(Grant No.B07014).
文摘As an important wide-bandgap semiconductor,gallium nitride(GaN)has attracted considerable attention.This paper describes the use of confocal Raman spectroscopy to characterize undoped GaN,n-type GaN,and p-type GaN through depth profiling using 405-,532-,and 638-nm wavelength lasers.The Raman signal intensity of the sapphire substrate at different focal depths is studied to analyze the depth resolution.Based on the shift of the E2 H mode of the GaN epitaxial layer,the interfacial stress for different types of GaN is characterized and calculated.The results show that the maximum interfacial stress appears approximately at the junction of the GaN and the sapphire substrate.Local interfacial stress analysis between the GaN epitaxial layer and the substrate will be very helpful in furthering the applications of GaN devices.
基金This work was supported by the National Natural Science Foundation of China(No.51575389,51761135106)the National Key Research and Development Program of China(2016YFB1102203)+1 种基金the State Key Laboratory of Precision Measuring Technology and Instruments(Pilt1705)the‘111’Project by the State Administration of Foreign Experts Affairs and the Ministry of Education of China(Grant No.B07014)。
文摘Silicon-vacancy(VSi)centers in silicon carbide(SiC)are expected to serve as solid qubits,which can be used in quantum computing and sensing.As a new controllable color center fabrication method,femtosecond(fs)laserwriting has been gradually applied in the preparation of VSi in SiC.In this study,4H-SiCwas directlywritten by an fs laser and characterized at 293 K by atomic force microscopy,confocal photoluminescence(PL),and Raman spectroscopy.PL signals of VSi were found and analyzed using 785 nm laser excitation by means of depth profiling and two-dimensional mapping.The influence of machining parameters on the VSi formation was analyzed,and the three-dimensional distribution of VSi defects in the fs laser writing of 4H-SiC was established.
文摘All organisms must transmit genetic information to offspring through cell division, and mitotic spindle participates in the process. Spindle dynamics through depolymerization or polymerization of microtubules generates the driving force required for chromosome movements in mitosis. To date, studies have shown that microtubule arrays control the directions of cell division and diverse microtubule-associated proteins regulate cell division. But a clear picture of how microtubules and microtubule-associated proteins modulate cell division remains unknown. Depletion of end-binding protein 1 by RNA-mediated inhibition shows that one of the microtubule-associated proteins, end-binding protein 1, plays a crucial role in mitotic spindle formation and promotes microtubule dynamics and is needed for the proper segregation of mitotic chromosomes during anaphase in Drosophila cells. Here, we review the properties of end-binding protein 1 and the roles of end-binding protein 1 in regulating microtubule behavior and in cell cycle.
基金support by National Key R&D Program of China(2023YFA1406304)supported by the National Key R&D Program of China(2022YFB3608000)+7 种基金National Natural Science Foundation of China(U2032208,11888101,92065201,U2032213,and 12222413)sponsored by Double First-Class Initiative Fund of ShanghaiTech University and the open projects from State Key Laboratory of Functional Materials for Informatics(SKL2022)supported by the National Key Research and Development Program of China(2022YFA1402704)the Natural Science Foundation of Shanghai(23ZR1482200 and 22ZR1473300)funded by the New Cornerstone Science FoundationChina National Postdoctoral Program for Innovative Talents(BX20240348)supported by ME2 project under Contract No.11227902 from the National Natural Science Foundation of Chinasupport from Analytical Instrumentation Center(#SPSTAIC10112914)。
文摘In solids,the reservation of symmetries defines the types of topological invariants that classify various topological quantum materials[1–3].Among them,the time-reversal symmetry(TRS)is the most fundamental,which plays key role in topological helical edge or surface states.Nevertheless,breaking TRS in topological materials typically gives rise to unexpected exotic states,such as magnetic Weyl semimetals,quantum anomalous Hall insulators,and axion insulators.
基金the National Natural Science Foundation of China(Nos.51575389,51761135106)National Key Research and Development Program of China(2016YFB1102203)+1 种基金State key laboratory of precision measuring technology and instruments(Piltl705)the‘111’Project by the State Administration of Foreign Experts Affairs and the Ministry of Education of China(Grant No.B07014)。
文摘Color centers in silicon carbide(SiC)are promising candidates for quantum technologies.However,the richness of the polytype and defect configuration of SiC makes the accurate control of the types and position of defects in SiC still challenging.In this study,helium ion-implanted 4H-SiC was characterized by atomic force microscopy(AFM),confocal photoluminescence(PL),and confocal Raman spectroscopy at room temperature.PL signals of silicon vacancy were found and analyzed using 638-nm and 785-nm laser excitation by means of depth profiling and SWIFT mapping.Lattice defects(C-C bond)were detected by continuous laser excitation at 532 nm and 638 nm,respectively.PL/Raman depth profiling was helpful in revealing the three-dimensional distribution of produced defects.Differences in the depth profiling results and SRIM simulation results were explained by considering the depth resolution of the confocal measurement setup,helium bubbles,as well as swelling.
基金supported by the National Natural Science Foundation of China(22278306,22278314,21621004 and 22078239)the State Key Laboratory of Chemical Engineering(SKL-ChE-21T03)。
基金supported by the National Natural Science Foundation of China(21621004,51773149,22078239)Tianjin Development Program for Innovation and Entrepreneurship(2018)the State Key Laboratory of Chemical Engineering(SKL-Ch E-20Z04,SKLCh E-21T03)。
文摘We report the coordination assembly of the ferrocene-diphenylalanine(Fc-FF)with divalent copper ions(Cu^(2+))into metalpeptide assemblies(MPAs)with hierarchical spiral architectures.The MPA particles are composed of helically organized nanofibers which can be correlated to the logarithmic spirals.The MPAs are hierarchically porous with abundant Fc and Cu2+active sites and show much higher catalytic activity than natural laccase toward the decolorization reaction.Moreover,a series of hierarchical structures of the MPAs can be synthesized by controlling the temperature and enantiomeric excess(ee).The peptide enantiomers with higher ee values will self-assemble into highly complex and ordered structures,which show higher surface area and porosity and thus enhanced catalytic activity compared with those assembled by peptides with lower ee values.The results provide new insights into the vital role of chirality in directing the self-assembly of biomolecules into highly ordered complex functional structures.
基金support from the National Natural Science Foundation of China(Nos.22138001 and 21521005)the National Key R&D Program of China(No.2017YFA0206804)is acknowledged.
文摘The direct conversion of ethanol to 1,1-diethoxyethane(DEE)through one-pot dehydrogenation-acetalization has attracted broad interest from both academia and industry.Based on thermodynamics,the oxidative dehydrogenation of alcohol to acetaldehyde requires high temperature to activate oxygen to realize the C-H cleavage,while the acetalization of acetaldehyde with ethanol is exothermic reversible reaction favorable at low temperature.The mismatching of the reaction condition for the two consecutive steps makes it a great challenge to achieve both high ethanol conversion and high DEE selectivity.This work reports a highly efficient bi-functional catalysis by Bi/BiCeO_(x)for one-pot oxidative dehydrogenation-acetalization route from ethanol to DEE under 150℃and ambient pressure,affording a selectivity of 98.5%±0.5%to DEE at an ethanol conversion of 87.0%±1.0%.An efficient tandem catalysis has been achieved on the interfacial Bi^(δ)+-Ov-Ce^(III)sites in Bi/BiCeO_(x)established by strong metal-support interaction,in which Biδ+-Ov-sites contribute to the oxidative dehydrogenation of ethanol at mild temperature,and-Ov-CeIII sites to the subsequent acetalization between the generated acetaldehyde and ethanol.
文摘Background Multimodal techniques-assisted resection of glioma under general anesthesia(GA)has been shown to achieve similar clinical outcomes as awake craniotomy(AC)in some studies.In this study,we aim to validate the use of multimodal techniques can achieve the maximal safe resection of high-grade glioma involving language areas(HGILAs)under GA.Methods HGILAs cases were reviewed and collected between January 2009 and December 2020 in our center.Patients were separated into multimodal group(using neuronavigation,intraoperative MRI combined with direct electrical stimulation[DES]and neuromonitoring[IONM])and conventional group(neuronavigation alone)and clinical outcomes were compared between groups.Studies of HGILAs were reviewed systematically and the meta-analysis results of previous(GA or AC)studies were compared with our results.Results Finally,there were 263 patients in multimodal group and 137 patients in conventional group.Compared to the conventional group,the multimodal group achieved the higher median EOR(100%versus 94.32%,P<0.001)and rate of gross total resection(GTR)(73.8%versus 36.5%,P<0.001)and the lower incidence of permanent language deficit(PLD)(9.5%versus 19.7%,P=0.004).The multimodal group achieved the longer median PFS(16.8 versus 10.3 months,P<0.001)and OS(23.7 versus 15.7 months,P<0.001)than the conventional group.The multimodal group achieved a higher rate of GTR than the cohorts in previous multimodal studies under GA and AC(73.8%versus 55.7%[95%CI 32.0-79.3%]versus 53.4%[35.5-71.2%]).The multimodal group had a lower incidence of PLD than the cohorts in previous multimodal studies under GA(9.5%versus 14.0%[5.8-22.1%])and our incidence of PLD was a little higher than that of previous multimodal studies under AC(9.5%versus 7.5%[3.7-11.2%]).Our multimodal group also achieved a relative longer survival than previous studies.Conclusions Surgery assisted by multimodal techniques can achieve maximal safe resection for HGILAs under GA.Further prospective studies are needed to compare GA with AC for HGILAs.
基金the National Key Research and Development Program of China(2021YFA1300502)the Natural Science Foundation of China(92057210,82125017,91942309)the Science and Technology Program of Guangzhou(202103000070)。
文摘Emerging lines of evidence have shown that the production of the covalently closed single-stranded circular RNAs is not splicing errors,but rather a regulated process with distinct biogenesis and turnover.Circular RNAs are expressed in a cell type-and tissue-specific manner and often localize to specific subcellular regions or organelles for functions.The dysregulation of circular RNAs from birth to death is linked to the pathogenesis and progression of diverse diseases.This review outlines how aberrant circular RNA biogenesis,subcellular location,and degradation are linked to disease progression,focusing on metaflammation and cancers.We also discuss potential therapeutic strategies and obstacles in targeting such disease-related circular RNAs.
基金This work was supported in part by Fundamental Funds for the Central University under Grant No.2018RC018the National Natural Science Foundation of China under Grant No.51807004the project of State Grid Shanghai Electrical Power Research Institute(B30940190000).
文摘After a major outage,mobile emergency resources(MERs)can be dispatched via the transportation system(TS)for service restoration to critical loads in the power distribution system(PDS).In this case study,the efficiency of service restoration in the PDS is associated with the traffic efficiency of the TS,and vice versa,because the PDS and TS are mutually coupled through traffic lights and MERs.This paper proposes a service restoration method considering interdependency between the PDS and TS,which is formulated as a mixed-integer linear program(MILP).The objective includes maximizing the efficiency of both PDS restoration and TS.By solving the MILP,the dynamic load restoration and MER dispatch strategies can be obtained.For the PDS,the availability of MERs,including mobile sources and repair crews,relates to their dispatch in the TS,and their relationship is formulated as mathematical models.For the TS,the dynamic traffic flow is modeled using the cell transmission model and the effect of traffic lights is considered.Case studies validate the effectiveness of the proposed method.
基金This work was funded by the National Natural Science Foundation of the China(#91949112,#81974052,#81921001,#91939302,and#31870930)Peking University Health Science Center,the Plan for Strengthening the Basic Research(#BMU2020JC002).
文摘Vascular smooth muscle cell (vSMC) is highly plastic as its phenotype can change in response to mechanical cues inherent to the extracellular matrix (ECM). VSMC may be activated from its quiescent contractile phenotype to a proinflammatory phenotype, whereby the cell secretes chemotactic and inflammatory cytokines, e.g. MCP1 and IL6, to functionally regulate monocyte and macrophage infiltration during the development of various vascular diseases including arteriosclerosis. Here, by culturing vSMCs on polyacrylamide (PA) substrates with variable elastic moduli, we discovered a role of discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that binds collagens, in mediating the mechanical regulation of vSMC gene expression, phenotype, and proinflammatory responses. We found that ECM stiffness induced DDR1 phosphorylation, oligomerization, and endocytosis to repress the expression of DNA methyltransferase 1 (DNMT1), very likely in a collagen-independent manner. The DDR1-to-DNMT1 signaling was sequentially mediated by the extracellular signal-regulated kinases (ERKs) and p53 pathways. ECM stiffness primed vSMC to a proinflammatory phenotype and this regulation was diminished by DDR1 inhibition. In agreement with the in vitro findings, increased DDR1 phosphorylation was observed in human arterial stiffening. DDR1 inhibition in mouse attenuated the acute injury or adenine diet-induced vascular stiffening and inflammation. Furthermore, mouse vasculature with SMC-specific deletion of Dnmt1 exhibited proinflammatory and stiffening phenotypes. Our study demonstrates a role of SMC DDR1 in perceiving the mechanical microenvironments and down-regulating expression of DNMT1 to result in vascular pathologies and has potential implications for optimization of engineering artificial vascular grafts and vascular networks.
基金was supported by grants from National Institutes of Health(R01DK089098 and P01DK57751)American Diabetes Association(1-19-IBS-119)+1 种基金X.Y.and a Glenn/AFAR Scholarship for Research in the Biology of Aging to M.-D.LYale School of Medicine and by the Office of The Director,National Institutes of Health(S10OD02365101A1,S10OD019967,and S10OD018034).
文摘O-linked N-acetyl-glucosamine glycosylation(O-GlcNAcylation)of intracellular proteins is a dynamic process broadly implicated in age-related disease,yet it remains uncharacterized whether and how O-GlcNAcylation contributes to the natural aging process.O-GlcNAc transferase(OGT)and the opposing enzyme O-GlcNAcase(OGA)control this nutrient-sensing protein modification in cells.Here,we show that global O-GlcNAc levels are increased in multiple tissues of aged mice.In aged liver,carbamoyl phosphate synthetase 1(CPS1)is among the most heavilyO-GlcNAcylated proteins.CPS1O-GlcNAcylation is reversed by calorie restriction and is sensitive to genetic and pharmacological manipulations of theO-GlcNAc pathway.High glucose stimulates CPS1O-GlcNAcylation and inhibits CPS1 activity.Liver-specific deletion of OGT potentiates CPS1 activity and renders CPS1 irresponsive to further stimulation by a prolonged fasting.Our results identify CPS1 O-GlcNAcylation as a key nutrient-sensing regulatory step in the urea cycle during aging and dietary restriction,implying a role for mitochondrial O-GlcNAcylation in nutritional regulation of longevity.
基金funding from the Major Science and Technique Programs in Yunnan Province(No.2019ZF011-1)the National Natural Science Foundation of China(No.81960689)+4 种基金the National Key R&D Program of China(2020YFC1316400)the Project of Young and Middle-Aged Talent of Yunnan Province(No.2019HB019)Science and Technology Innovation team of Yunnan(No.202105AE160011)Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(No.TSBICIP-KJGG-002-02)the Tianjin Science Fund for Distinguished Young Scholars(No.18JCJQJC48300).
文摘Scutellarin related drugs have superior therapeutic effects on cerebrovascular and cardiovascular diseases.Here,an optimal biosynthetic pathway for scutellarin was constructed in Yarrowia lipolytica platform due to its excellent metabolic potential.By integrating multi-copies of core genes from different species,the production of scutellarin was increased from 15.11 mg/L to 94.79 mg/L and the ratio of scutellarin to the main by-product was improved about 110-fold in flask condition.Finally,the production of scutellarin was improved 23-fold and reached to 346 mg/L in fed-batch bioreactor,which was the highest reported titer for de novo production of scutellarin in microbes.Our results represent a solid basis for further production of natural products on unconventional yeasts and have a potential of industrial implementation.
基金This work was supported by the National High Technology Key Research and Development Program of China(No.2016YFD0200900)the Provincial Natural Science Foundation of Guangdong,China(No.2016 A030313773).
文摘Vermicomposting is an efficient and environmentally friendly technology to dispose of agricultural organic residues.The efficiency of organic residue decomposition during vermicomposting is directly affected by the biomass and population structure of earthworms.In this study,we investigated how the earthworm biomass and population structure responded to changes in the physicochemical properties of six types of organic residue(cattle dung,herbal waste,rice straw,soybean straw,garden waste,and tea residues)during vermicomposting.Each type of organic residues was placed in a pot with earthworms Eisenia fetida,and the physicochemical properties of the organic residues and earthworm growth dynamics were recorded at 0,30,60,and 90 d of vermicomposting.The biomass and population structure of earthworms were stable or increased in rice straw,garden waste,and cattle dung within 60 d of vermicomposting,whereas in tea residues and herb waste,very little earthworm activity(3 adults and 2 cocoons)was recorded on day 30.Among the physicochemical parameters,the substrate C/N ratio was negatively correlated with earthworm growth dynamics.Decomposing organic residues showed higher NH_(4)^(+)-N and NH_(3)^(-)-N concentrations but a lower total organic carbon content,which negatively affected earthworm growth and reproduction.We recommend that chemical properties of vermicomposting systems should be monitored regularly.At the threshold levels of decomposing organic residue NH_(4)^(+)-N and NH_(3)^(-)-N concentrations,earthworms should be removed and the vermicompost can be harvested.Small-and large-scale farmers thus need to monitor the physicochemical properties of vermicompost to sustain active earthworm populations.
基金supported by the National Natural Science Foundation of China(21621004 and 22078239)Tianjin Development Program for Innovation and Entrepreneurship(2018)the State Key Laboratory of Chemical Engineering(SKL-Ch E-20Z04 and SKL-Ch E-21T03)。
文摘Fibonacci number spiral patterns can be found in nature,particularly in plants,such as the sunflowers and phyllotaxis.Here,we demonstrated this pattern can be reproduced spontaneously within self-assembling peptide nanofibril films.By high-temperature water vapor annealing of an amorphous film containing both peptide and cationic diamines,well-defined amyloid-like nanofibrils can be assembled spontaneously,during which the nanofibrils will hierarchically stack with each other following the Fibonacci number patterns.The formation of the patterns is a selftemplated process,which involves stepwise chiral amplification from the molecular scale to the nano-and micro-scales.Moreover,by controlling the diameter,length,and handedness of the nanofibrils,various complex hierarchical structures could be formed,including vertically aligned nanoarray,mesoscale helical bundles,Fibonacci number spirals,and then helical toroids.The results provide new insights into the chiral self-assembly of simple biological molecules,which can advance their applications in optics and templated synthesis.
