Celecoxib,a cyclooxygenase-2 inhibitor,can enhance the efficacy of chemotherapy;however,its effect seems inconsistent.In this study,we investigated whether celecoxib would increase the antiproliferative effects of cis...Celecoxib,a cyclooxygenase-2 inhibitor,can enhance the efficacy of chemotherapy;however,its effect seems inconsistent.In this study,we investigated whether celecoxib would increase the antiproliferative effects of cisplatin in human lung cancer cells.Our data demonstrated the synergistic effects of celecoxib with cisplatin in wild-type p53 cells and their antagonistic effects inmutated or deleted p53 cells.Combination indices of 0.82 to 0.93 reflected a synergistic effect between celecoxib and cisplatin in lung cancer cells with wild-type p53.Combination indices of 1.63 to 3.00 reflected antagonism between celecoxib and cisplatin in lung cancer cells with mutated or deleted p53.Compared with that in cells with mutated or deleted p53,apoptosis significantly increased with the addition of celecoxib and cisplatin in wild-type p53 cells(P<0.05).Moreover,the results in vivo were similar to those in vitro:celecoxib combinedwith cisplatin slowed tumor growth in wild-type p53 groups and not in mutated or deleted p53 groups.In addition,celecoxib promoted p53 translocation into the nucleus and upregulated active p53 expression in wild-type p53 cells.Celecoxib combined with cisplatin upregulated PUMA(PUMA is a downstream gene of p53)after active p53 increased in wild-type p53 cells.In summary,the combination of celecoxib and cisplatin demonstrates clear synergistic effects in wild-type p53 cells and antagonistic effects inmutated or deleted p53 cells.The synergistic effect was achieved by apoptosis,induced by upregulating PUMA.Our results will provide a new treatment strategy for patients carrying wild-type p53,insensitive to cisplatin.展开更多
Variations in the dynein axonemal heavy chain gene,dynein axonemal heavy chain 6(DNAH6),lead to multiple morphological abnormalities of the flagella.Recent studies have reported that these deficiencies may result in s...Variations in the dynein axonemal heavy chain gene,dynein axonemal heavy chain 6(DNAH6),lead to multiple morphological abnormalities of the flagella.Recent studies have reported that these deficiencies may result in sperm head deformation.However,whether DNAH6 is also involved in human acrosome biogenesis remains unknown.The purpose of this study was to investigate DNAH6 gene variants and their potential functions in the formation of defective sperm heads and flagella.Whole-exome sequencing was performed on a cohort of 375 patients with asthenoteratozoospermia from the First Affiliated Hospital of Anhui Medical University(Hefei,China).Hematoxylin and eosin staining,scanning electron microscopy,and transmission electron microscopy were performed to analyze the sperm morphology and ultrastructure.Immunofluorescence staining and Western blot analysis were conducted to examine the effects of genetic variants.We identified three novel deleterious variants in DNAH6 among three unrelated families.The absence of inner dynein arms and radial spokes was observed in the sperm of patients with DNAH6 variants.Additionally,deficiencies in the acrosome,abnormal chromatin compaction,and vacuole-containing sperm heads were observed in these patients with DNAH6 variants.The decreased levels of the component proteins in these defective structures were further confirmed in sperm from patients with DNAH6 variants using Western blot.After intracytoplasmic sperm injection(ICSl)treatment,the partner of one patient with a DNAH6 variant achieved successful pregnancy.Overall,novel variants in DNAH6 genes that contribute to defects in the sperm head and flagella were identified,and the findings indicated Icsl as an effective clinical treatment for such patients.展开更多
The electrochemical reduction of CO_(2) towards hydrocarbons is a promising technology that can utilize CO_(2) and prevent its atmospheric accumulation while simultaneously storing renewable en‐ergy.However,current C...The electrochemical reduction of CO_(2) towards hydrocarbons is a promising technology that can utilize CO_(2) and prevent its atmospheric accumulation while simultaneously storing renewable en‐ergy.However,current CO_(2) electrolyzers remain impractical on a large scale due to the low current densities and faradaic efficiencies(FE)on various electrocatalysts.In this study,hybrid HKUST‐1 metal‐organic framework‒fluorinated imidazolium‐based room temperature ionic liquid(RTIL)electrocatalysts are designed to selectively reduce CO_(2) to CH_(4).An impressive FE of 65.5%towards CH_(4) at-1.13 V is achieved for the HKUST‐1/[BMIM][PF_(6)]hybrid,with a stable FE greater than 50%maintained for at least 9 h in an H‐cell.The observed improvements are attributed to the increased local CO_(2) concentration and the improved CO_(2)‐to‐CH_(4) thermodynamics in the presence of the RTIL molecules adsorbed on the HKUST‐1‐derived Cu clusters.These findings offer a novel approach of immobilizing RTIL co‐catalysts within porous frameworks for CO_(2) electroreduction applications.展开更多
The aim of this study was to explore the optimal timing of holmium laser enucleation of the prostate(HoLEP)in patients presenting benign prostatic hyperplasia(BPH)with lower urinary tract symptoms(LUTS).A retrospectiv...The aim of this study was to explore the optimal timing of holmium laser enucleation of the prostate(HoLEP)in patients presenting benign prostatic hyperplasia(BPH)with lower urinary tract symptoms(LUTS).A retrospective analysis was conducted based on the perioperative and postoperative outcome data of 1212 patients who underwent HoLEP in Shanghai Ninth People’s Hospital(Shanghai,China)between January 2009 and December 2018.According to the preoperative International Prostate Symptom Score(IPSS),all patients whom we analyzed were divided into Group A(IPSS of 8–18)and Group B(IPSS of 19–35).Peri-and postoperative outcome data were obtained during the 1-year follow-up.IPSS changes were the main postoperative outcomes.The postoperative IPSS,quality of life,peak urinary flow rate,postvoid residual,and overactive bladder symptom score(OABSS)improved significantly.The IPSS improved further in the group with severe LUTS symptoms,but the postoperative IPSS was still higher than that in the moderate LUTS group.OABSSs showing moderate and severe cases after follow-up were more frequent in Group B(9.1%)than in Group A(5.2%)(P<0.05).There were no significant intergroup differences in the intraoperative American Society of Anesthesiologists or hospitalization expense scores,and the medication costs,as well as the total costs,were significantly higher in Group B.In this retrospective study,HoLEP was an effective treatment for symptomatic BPH.For patients with LUTS,earlier surgery in patients with moderate severity may result in a marginally better 12-month IPSS than that in men with severe symptoms.展开更多
Objective:To investigate the mechanism of action of Wuzi Yanzong pill(WYP)in rats with oligoasthenozoospermia(OAZ)via metabolomics and to provide a possible basis for improving this WYP-based treatment.Methods:A rat m...Objective:To investigate the mechanism of action of Wuzi Yanzong pill(WYP)in rats with oligoasthenozoospermia(OAZ)via metabolomics and to provide a possible basis for improving this WYP-based treatment.Methods:A rat model of OAZ was established by treating male SpragueeDawley rats with glucosides from Tripterygium wilfordii Hook.F.Seventy-two rats were randomly divided into six groups:control,L-carnitine(positive control),model,and low-,medium-,and high-dose WYP groups.Rats in the experimental groups were treated with WYP for 4 weeks.At the end of the treatment period,sperm cell quality(density,motility,and viability)was assessed using a semen analysis system,mitochondrial membrane potential(MMP)was assessed using flow cytometry,and testicular injury was assessed using hematoxylin and eosin staining to validate the therapeutic effect of WYP in OAZ.Further,serum metabolomics-based analysis was performed using high-performance liquid chromatography-mass spectrometry to identify differential metabolic pathways and possible mechanisms of action of WYP in OAZ treatment.Results:A rat model of OAZ was considered successfully-established after comparing the quality of spermatozoa in the model group to that in the control group.WYP-M and WYP-H treatments significantly improved sperm cell density,motility,and viability compared with those in the model group(all P<.05).Compared with the model group,both WYP-M and WYP-H treatments increased MMP values(P=.006 and P=.021 respectively),while there was no significant difference in the L-carnitine group.L-carnitine and WYP administration reversed damage to the testes to varying degrees compared with that in the model group.Further,44 differential metabolites and four metabolic pathways,especially autophagy pathway,related to OAZ were identified via metabolomics.Conclusions:WYP improves sperm cell quality and MMP in OAZ primarily via autophagy regulation.These findings can be employed to improve the efficacy of WYP in humans.展开更多
Five types of polyurea elastomers were synthesized by changing the isocyanate component and the mechanical properties of polyurea materials were measured. Fiber-reinforced cement boards(FRCB)strengthened by polyurea w...Five types of polyurea elastomers were synthesized by changing the isocyanate component and the mechanical properties of polyurea materials were measured. Fiber-reinforced cement boards(FRCB)strengthened by polyurea with different formulations were processed, and a series of experiments were carried out on the specimens with gas explosion devices. The results showed that the conventional mechanical properties of different types of polyureas had their own advantages. Based on the gas explosion overpressure criterion, the blast resistances of reinforced plates were quantitatively evaluated,and the best polyurea was selected to guide the formulation design. The three typical failure modes of polyurea-reinforced FRCBs were flexural, shear, and flexural-shear failure. Dynamic thermodynamics and shock wave spectral analysis revealed that the polyurea did not undergo a glass transition in the gas explosion tests but retained its elastic properties, allowing it to effectively wrap the fragments formed by the brittle substrates.展开更多
Objective Long-term cigarette smoke exposure damages the airway epithelium.However,the correlation among GSTM1 gene polymorphism,smoking status,and lung cancer susceptibility remains unclear.This study aimed to identi...Objective Long-term cigarette smoke exposure damages the airway epithelium.However,the correlation among GSTM1 gene polymorphism,smoking status,and lung cancer susceptibility remains unclear.This study aimed to identify the genetic polymorphism of GSTM1 and examine the association of GSTM1 polymorphism and smoking history with lung cancer susceptibility.Methods The genetic polymorphism of GSTM1 was genotyped by polymerase chain reaction(PCR) in 217 lung cancer patients and 198 controls.The demographic data and smoking history of the patients were collected.The age,sex,and residence of the two groups were also obtained.Results Significant differences in GSTM1 polymorphism were observed between the case and control groups(P=0.024).Smoking time and smoking index were significantly different between the case and control groups.With the increase in smoking time and smoking index,the differences became more obvious.There was a synergistic effect between GSTM1 and smoking(S=3.35).The risk of developing lung cancer increased 4.82 fold in smokers carrying deficient-type GSTM1.Compared with patients carrying wild-type GSTM1,the risk of developing lung cancer was higher in those carrying deficient-type GSTM1 with the increase in smoking time and smoking index.In different pathological types,no significant differences were observed in GSTM1 polymorphism.In different pathological types,the proportions of patients increased with the increase in smoking time and smoking index,especially the proportion of patients with squamous cell carcinoma.Compared with wild-type GSTM1,the proportion of patients with deficient-type GSTM1 increased with the increase in smoking time and smoking index(P=0.003 and 0.017).This trend was mainly observed in those with squamous cell carcinoma.Conclusion GSTM1 mutation is associated with lung cancer susceptibility.Smokers carrying deficienttype GSTM1 are more likely to develop lung cancer.Compared with patients carrying wild-type GSTM1,smokers with deficient-type GSTM1 are more likely develop lung cancer when smoking time is more than 30 years and smoking index is more than 400.In patients carrying deficient-type GSTM1,the risk of developing squamous cell carcinoma increases with an increase in smoking time and smoking dose.展开更多
Objective Platinum-based chemotherapy is the first-line treatment for non-small cell lung cancer,but the chemoresistance of tumor cells continues to be a considerable challenge in the management of NSCLCs,leading to r...Objective Platinum-based chemotherapy is the first-line treatment for non-small cell lung cancer,but the chemoresistance of tumor cells continues to be a considerable challenge in the management of NSCLCs,leading to recurrence of most patients.CD133(prominin-1)is a five-transmembrane glycoprotein,and recent evidence suggests that CD133+cells are the cause of drug resistance and tumor recurrence.In this study,the correlation between cisplatin and CD133+cells was investigated systematically.Methods Four lung cancer cell lines,including A549,H460,801D and H1299,were treated with different concentrations of cisplatin.Cell viability was determined by MTT assay.Sphere-forming assay was performed to detect the capability of sphere-forming.CD133+cells was detected by BD FACScaliber flow cytometer.Results The results showed that cisplatin could increase the number of CD133+cells in both time-and dose-dependent manner.The enrichment would weaken but the proportion of CD133+cells was still higher than the basic level as incubation time extended after cisplatin was withdrawn.Compared with adherent culture,the proportion of CD133+cells was higher when the cells were maintained suspension culture.The proportion of CD133+cells significantly increased when cisplatin was provided in suspension culture.Conclusion These results revealed that cisplatin induces the enrichment of CD133+cells and CD133 is a new therapeutic target.Our data partially explained drug resistance to second-line chemotherapy in cisplatin-treated patients with NSCLCs.展开更多
Objective: We aimed to examine the expression of cyclooxygenase-2 and the relationship with the pathological types, TNM stage, lymph node metastasis, the degree of differentiation, smoking and the survival. Methods: I...Objective: We aimed to examine the expression of cyclooxygenase-2 and the relationship with the pathological types, TNM stage, lymph node metastasis, the degree of differentiation, smoking and the survival. Methods: Immunohistochemical staining method was used to examine the expression of cyclooxygenase-2 of 121 cases of lung cancer and three control groups. The data were statistically analyzed. Results: Compared with the health group, cyclooxygenase-2 was over expressed in the inflammatory tissue(P = 0.036), lung adenocarcinoma(P = 0.005) and squamous carcinoma(P = 0.047). Compared with patients without lymph node metastasis, cyclooxygenase-2 was over expressed(P = 0.033) in patients with lymph node metastasis. Compared with high differentiation group, cyclooxygenase-2 was over expressed(P = 0.004) in low differentiation group. Compared with non-smokers, the expression of cyclooxygenase-2 increased in smokers(P = 0.000). The median survival time of patients that the expression of cyclooxygenase-2 were negative was 9 months(95% CI, 5.6–12.4 months). The median survival time of patients that the expression of cyclooxygenase-2 were positive was 5 months(95% CI, 3–7 months). They was statistical difference(P = 0.001). Conclusion: Overexpression of cyclooxygenase-2 is associated with pathological types, TNM stage, lymph node metastasis, degrees of differentiation, smoking and prognosis in lung cancer.展开更多
Perovskite solar cells(PSCs)commonly exhibit significant performance degradation due to ion migration through the top charge transport layer and ultimately metal electrode corrosion.Here,we demonstrate an interfacial ...Perovskite solar cells(PSCs)commonly exhibit significant performance degradation due to ion migration through the top charge transport layer and ultimately metal electrode corrosion.Here,we demonstrate an interfacial management strategy using a boron chloride subphthalocyanine(Cl_(6)SubPc)/fullerene electron-transport layer,which not only passivates the interfacial defects in the perovskite,but also suppresses halide diffusion as evidenced by multiple techniques,including visual element mapping by electron energy loss spectroscopy.As a result,we obtain inverted PSCs with an efficiency of 22.0%(21.3%certified),shelf life of 7000 h,T_(80) of 816 h under damp heat stress(compared to less than 20 h without Cl_(6)SubPc),and initial performance retention of 98%after 2000 h at 80℃in inert environment,90%after 2034 h of illumination and maximum power point tracking in ambient for encapsulated devices and 95%after 1272 h outdoor testing ISOS-O-1.Our strategy and results pave a new way to move PSCs forward to their potential commercialization solidly.展开更多
The electrochemical reduction reaction of carbon dioxide(CO_(2)RR)is considered to be an effective way to realize carbon neutrality.As a type of intensively studied materials,covalent organic frameworks(COFs)with a tu...The electrochemical reduction reaction of carbon dioxide(CO_(2)RR)is considered to be an effective way to realize carbon neutrality.As a type of intensively studied materials,covalent organic frameworks(COFs)with a tunable pore structure and various functional groups are promising catalysts for CO_(2)RR.Herein,COF synthesized by 2,6‐diaminoanthraquinone and 2,4,6‐triformylphloroglucinol is employed to assist the synthesis of electrocatalysts from Cu single atoms(SAs)to nanoclusters by controlling the electrodeposition.A tandem catalyst for CO_(2)‐to‐CH4 conversion is thus achieved by the Cu nanoclusters dispersed among the isolated Cu SAs in the COF network.It is proposed that CO_(2) is first reduced to CO over the atomically isolated Cu SAs,followed by diffusion onto the neighboring Cu nanoclusters for further reduction into CH4.In addition,mechanistic analysis suggests that the coordinated K^(+)ions on the COF network promote the activation of CO_(2) and the adsorption of reaction intermediates,thus realizing the suppressed hydrogen evolution reaction and selective production of CH4.This study presents a new insight of COFs for the confined synthesis of a tunable SA to nanocluster electrocatalysts,disclosing the great potential of COFs in electrocatalysis.展开更多
As confusion mounts over RNA isoforms involved in phenotypic plasticity,aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity(ITH).Prot...As confusion mounts over RNA isoforms involved in phenotypic plasticity,aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity(ITH).Protease serine 3(PRSS3),possessing four splice variants(PRSS3-SVs;PRSS3-V1—V4),is an indispensable trypsin that shows paradoxical effects on cancer development.Here,we found that PRSS3 transcripts and their isoforms were divergently expressed in lung cancer,exhibiting opposing functions and clinical outcomes,namely,oncogenic PRSS3-V1 and PRSS3-V2 versus tumorsuppressive PRSS3-V3,by targeting different downstream genes.We identified an intragenic CpG island(iCpGI)in PRSS3.Hypermethylation of iCpGI was mediated by UHRF1/DNMT1 complex interference with the binding of myeloid zinc finger 1(MZF1)to regulate PRSS3 transcription.The garlic-derived compound diallyl trisulfide cooperated with 5-aza-2'-deoxycytidine to exert antitumor effects in lung adenocarcinoma cells through site-specific iCpGI demethylation specifically allowing MZF1 to upregulate PRSS3-V3 expression.Epigenetic silencing of PRSS3-V3 via i CpGI methylation(iCpGIm)in BALF and tumor tissues was associated with early clinical progression in patients with lung cancer but not in those with squamous cell carcinoma or inflammatory disease.Thus,UHRF1/DNMT1—MZF1 axismodulated site-specific iCpGIm regulates divergent expression of PRSS3-SVs,conferring nongenetic functional ITH,with implications for early detection of lung cancer and targeted therapies.展开更多
Solar-driven N_(2) fixation using a photocatalyst in water presents a promising alternative to the traditional Haber-Bosch process in terms of both energy efficiency and environmental concern.At present,the product of...Solar-driven N_(2) fixation using a photocatalyst in water presents a promising alternative to the traditional Haber-Bosch process in terms of both energy efficiency and environmental concern.At present,the product of solar N_(2) fixation is either NH_(4)^(+)or NO_(3)^(-).Few reports described the simultaneous formation of ammonia(NH_(4)^(+))and nitrate(NO_(3)^(-))by a photocatalytic reaction and the related mechanism.In this work,we report a strategy to photocatalytically fix nitrogen through simultaneous reduction and oxidation to produce NH_(4)^(+)and NO_(3)^(-)byW18O49 nanowires in pure water.The underlying mechanism of wavelength-dependent N_(2) fixation in the presence of surface defects is proposed,with an emphasis on oxygen vacancies that not only facilitate the activation and dissociation of N_(2) but also improve light absorption and the separation of the photoexcited carriers.Both NH_(4)^(+)and NO_(3)^(-)can be produced in pure water under a simulated solar light and even till the wavelength reaching 730 nm.The maximum quantum efficiency reaches 9%at 365 nm.Theoretical calculation reveals that disproportionation reaction of the N_(2) molecule is more energetically favorable than either reduction or oxidation alone.It is worth noting that the molar fraction of NH_(4)^(+)in the total product(NH_(4)^(+)plus NO_(3)^(-))shows an inverted volcano shape from 365nm to 730 nm.The increased fraction of NO_(3)^(-)from 365 nm to around 427 nm results from the competition between the oxygen evolution reaction(OER)at W sites without oxygen vacancies and the N_(2) oxidation reaction(NOR)at oxygen vacancy sites,which is driven by the intrinsically delocalized photoexcited holes.From 427nm to 730 nm,NOR is energetically restricted due to its higher equilibrium potential than that of OER,accompanied by the localized photoexcited holes on oxygen vacancies.Full disproportionation of N_(2) is achieved within a range of wavelength from~427nm to~515 nm.This work presents a rational strategy to efficiently utilize the photoexcited carriers and optimize the photocatalyst for practical nitrogen fixation.展开更多
As an innovative development of single-atom catalysts(SACs),single-cluster catalysts(SCCs)such as dualatom catalysts have attracted considerable interest due to their excellent performance in catalysis.As one of the m...As an innovative development of single-atom catalysts(SACs),single-cluster catalysts(SCCs)such as dualatom catalysts have attracted considerable interest due to their excellent performance in catalysis.As one of the most powerful and visualizable tools,scanning transmission electron microscopy(STEM)has been widely applied in the characterization of SCCs.Herein,the nitrogen-doped carbonsupported FeFe and CoFe,two representative examples of homonuclear and heteronuclear SCCs,are characterized by STEM.Furthermore,an image processing program is developed to analyze the STEM images and to obtain the locations of atoms,as well as the projected distances between atoms in possible dual-atom pairs.The dimer distances of both CoFe and FeFe catalysts exhibit a trimodal distribution,which can correspond to the energy-favorable atomic structures of the theoretical simulations.Our work offers an avenue for directly revealing the possible atomic configurations of dual-atom sites in SCCs via big data statistics of STEM images and strong theoretical simulations.展开更多
As a promising anode material candidate for sodium-ion batteries,antimony(Sb)has attracted enormous research interest due to its high specific capacity and low sodiation voltage.However,its dramatic volume expansion u...As a promising anode material candidate for sodium-ion batteries,antimony(Sb)has attracted enormous research interest due to its high specific capacity and low sodiation voltage.However,its dramatic volume expansion upon sodiation adversely affects its cycle stability.We have developed an oxidation-coating-reduction strategy for fabricating yolk-shell Sb@C rods from commercially available Sb powder.In particular,the thermal reduction of vaporized Sb_(2)O_(3) generates densely distributed Sb single atoms and clusters on the carbon shell.The sodiation process of the Sb@C sample was recorded through in situ transmission electron microscopy.Irregular expansion of Sb particles was observed,and it was also revealed that the carbon shell could deform with the expanded Sb particles.Beyond the intuitively understood advantage that internal voids can provide space for expansion of internal active materials,the deformability of carbon shells can add further ability to withstand the volume expansion.The two structural merits of the yolk-shell construction enable the Sb@C material to deliver an enhanced cycle performance.Its reversible capacity exceeds 620 mA h g^(−1) at 0.1C,with an initial coulombic efficiency of up to 84.9%,and about 95%of the capacity in the charging voltage profile is delivered below 1.0 V vs.Na+/Na.These performance metrics are very promising for potential practical applications.展开更多
This work presents simple post-treatment methods to selectively and partially remove the Pd core of Pd-Pt core–shell(Pt@Pd/C)catalysts.The proton exchange membrane fuel cell with the post-treated Pt@Pd/C cathode(Pt l...This work presents simple post-treatment methods to selectively and partially remove the Pd core of Pd-Pt core–shell(Pt@Pd/C)catalysts.The proton exchange membrane fuel cell with the post-treated Pt@Pd/C cathode(Pt loading:0.10 mg·cm^(-2))delivers an impressive peak power density of 1.2 W·cm^(-2).The partial removal of Pd core endows an ultrahigh oxygen reduction reaction(ORR)mass activity of 0.32 A·g_(PGM)-1 when normalized to the platinum group metal(PGM)mass,or equivalently 0.55 A·mg_(Pt)^(-1) at 0.9 V measured in a fuel cell.The post-treatment thickens the Pt shells and mitigates the Pd dissolution during potential cycling.As a result,the post-treated core-shell catalyst demonstrates superior durability in ORR mass activity and polarization power density retention than untreated core-shell catalyst and benchmark Pt/C.In-situ inductively coupled plasmamass spectrometry(ICP-MS)results highlight that the amount of dissolved Pd in post-treated core–shell catalyst is 17-times lower than that of the untreated one.Our findings highlight the importance of structural tuning of catalysts in enhancing their mass activity and durability.展开更多
Summary of main observation and conclusion Atomistic dynamics of protonated polyglycine,glyn-H^+(n=3,5,and 7),colliding with a fluorinated octanethiol self-assembled monolayer(F-SAM)surface has been studied by traject...Summary of main observation and conclusion Atomistic dynamics of protonated polyglycine,glyn-H^+(n=3,5,and 7),colliding with a fluorinated octanethiol self-assembled monolayer(F-SAM)surface has been studied by trajectory calculations.The effects of peptide size on the collision processes and energy transfer efficiencies are emphasized and discussed in detail.The simulations show that the fraction of trapping,which is related to the soft-landing process,dramatically drops with the in crease in collisi on energy,but gently increases with the peptide size.The average energy transfer to the peptide ion's internal degrees of freedom,AEint,is compared with previous experiments.The limiting probability Po of energy transfer to the surface is given by fitting a function of Poexp(—b/&).Our results suggest that the efficiencies of energy transfer are less dependent on the masses,even the categories of the peptide ions,and are determined by the character of the surfaces.展开更多
基金the Beijing Municipal Science and Technology Commission(grant Z211100002921013)the Tongzhou District Science and Technology Committee Project to Tongzhou(grant KJ2020CX010).
文摘Celecoxib,a cyclooxygenase-2 inhibitor,can enhance the efficacy of chemotherapy;however,its effect seems inconsistent.In this study,we investigated whether celecoxib would increase the antiproliferative effects of cisplatin in human lung cancer cells.Our data demonstrated the synergistic effects of celecoxib with cisplatin in wild-type p53 cells and their antagonistic effects inmutated or deleted p53 cells.Combination indices of 0.82 to 0.93 reflected a synergistic effect between celecoxib and cisplatin in lung cancer cells with wild-type p53.Combination indices of 1.63 to 3.00 reflected antagonism between celecoxib and cisplatin in lung cancer cells with mutated or deleted p53.Compared with that in cells with mutated or deleted p53,apoptosis significantly increased with the addition of celecoxib and cisplatin in wild-type p53 cells(P<0.05).Moreover,the results in vivo were similar to those in vitro:celecoxib combinedwith cisplatin slowed tumor growth in wild-type p53 groups and not in mutated or deleted p53 groups.In addition,celecoxib promoted p53 translocation into the nucleus and upregulated active p53 expression in wild-type p53 cells.Celecoxib combined with cisplatin upregulated PUMA(PUMA is a downstream gene of p53)after active p53 increased in wild-type p53 cells.In summary,the combination of celecoxib and cisplatin demonstrates clear synergistic effects in wild-type p53 cells and antagonistic effects inmutated or deleted p53 cells.The synergistic effect was achieved by apoptosis,induced by upregulating PUMA.Our results will provide a new treatment strategy for patients carrying wild-type p53,insensitive to cisplatin.
基金This work was supported by the National Natural Science Foundation of China(No.82071705)University Outstanding Youth Program of Anhui Provincial Education Department(2022AH030113)+1 种基金University Outstanding Young Talents Support Program(gxyq2021174)Postgraduate Innovation Research and Practice Program of Anhui Medical University(No.YJS20210327).
文摘Variations in the dynein axonemal heavy chain gene,dynein axonemal heavy chain 6(DNAH6),lead to multiple morphological abnormalities of the flagella.Recent studies have reported that these deficiencies may result in sperm head deformation.However,whether DNAH6 is also involved in human acrosome biogenesis remains unknown.The purpose of this study was to investigate DNAH6 gene variants and their potential functions in the formation of defective sperm heads and flagella.Whole-exome sequencing was performed on a cohort of 375 patients with asthenoteratozoospermia from the First Affiliated Hospital of Anhui Medical University(Hefei,China).Hematoxylin and eosin staining,scanning electron microscopy,and transmission electron microscopy were performed to analyze the sperm morphology and ultrastructure.Immunofluorescence staining and Western blot analysis were conducted to examine the effects of genetic variants.We identified three novel deleterious variants in DNAH6 among three unrelated families.The absence of inner dynein arms and radial spokes was observed in the sperm of patients with DNAH6 variants.Additionally,deficiencies in the acrosome,abnormal chromatin compaction,and vacuole-containing sperm heads were observed in these patients with DNAH6 variants.The decreased levels of the component proteins in these defective structures were further confirmed in sperm from patients with DNAH6 variants using Western blot.After intracytoplasmic sperm injection(ICSl)treatment,the partner of one patient with a DNAH6 variant achieved successful pregnancy.Overall,novel variants in DNAH6 genes that contribute to defects in the sperm head and flagella were identified,and the findings indicated Icsl as an effective clinical treatment for such patients.
文摘The electrochemical reduction of CO_(2) towards hydrocarbons is a promising technology that can utilize CO_(2) and prevent its atmospheric accumulation while simultaneously storing renewable en‐ergy.However,current CO_(2) electrolyzers remain impractical on a large scale due to the low current densities and faradaic efficiencies(FE)on various electrocatalysts.In this study,hybrid HKUST‐1 metal‐organic framework‒fluorinated imidazolium‐based room temperature ionic liquid(RTIL)electrocatalysts are designed to selectively reduce CO_(2) to CH_(4).An impressive FE of 65.5%towards CH_(4) at-1.13 V is achieved for the HKUST‐1/[BMIM][PF_(6)]hybrid,with a stable FE greater than 50%maintained for at least 9 h in an H‐cell.The observed improvements are attributed to the increased local CO_(2) concentration and the improved CO_(2)‐to‐CH_(4) thermodynamics in the presence of the RTIL molecules adsorbed on the HKUST‐1‐derived Cu clusters.These findings offer a novel approach of immobilizing RTIL co‐catalysts within porous frameworks for CO_(2) electroreduction applications.
基金This research was supported by grant from the multi-center clinical research project of Shanghai Jiao Tong University School of Medicine(grant No.DLY201809)grant from the 2021 Shanghai Science and Technology Innovation Cooperation Program of Science and Technology Commission of Shanghai Municipality(grant No.21015801700)。
文摘The aim of this study was to explore the optimal timing of holmium laser enucleation of the prostate(HoLEP)in patients presenting benign prostatic hyperplasia(BPH)with lower urinary tract symptoms(LUTS).A retrospective analysis was conducted based on the perioperative and postoperative outcome data of 1212 patients who underwent HoLEP in Shanghai Ninth People’s Hospital(Shanghai,China)between January 2009 and December 2018.According to the preoperative International Prostate Symptom Score(IPSS),all patients whom we analyzed were divided into Group A(IPSS of 8–18)and Group B(IPSS of 19–35).Peri-and postoperative outcome data were obtained during the 1-year follow-up.IPSS changes were the main postoperative outcomes.The postoperative IPSS,quality of life,peak urinary flow rate,postvoid residual,and overactive bladder symptom score(OABSS)improved significantly.The IPSS improved further in the group with severe LUTS symptoms,but the postoperative IPSS was still higher than that in the moderate LUTS group.OABSSs showing moderate and severe cases after follow-up were more frequent in Group B(9.1%)than in Group A(5.2%)(P<0.05).There were no significant intergroup differences in the intraoperative American Society of Anesthesiologists or hospitalization expense scores,and the medication costs,as well as the total costs,were significantly higher in Group B.In this retrospective study,HoLEP was an effective treatment for symptomatic BPH.For patients with LUTS,earlier surgery in patients with moderate severity may result in a marginally better 12-month IPSS than that in men with severe symptoms.
基金supported by the Longitudinal Development Project of the Beijing University of Chinese Medicine(2018-zxfzjj002,Beijing,China).
文摘Objective:To investigate the mechanism of action of Wuzi Yanzong pill(WYP)in rats with oligoasthenozoospermia(OAZ)via metabolomics and to provide a possible basis for improving this WYP-based treatment.Methods:A rat model of OAZ was established by treating male SpragueeDawley rats with glucosides from Tripterygium wilfordii Hook.F.Seventy-two rats were randomly divided into six groups:control,L-carnitine(positive control),model,and low-,medium-,and high-dose WYP groups.Rats in the experimental groups were treated with WYP for 4 weeks.At the end of the treatment period,sperm cell quality(density,motility,and viability)was assessed using a semen analysis system,mitochondrial membrane potential(MMP)was assessed using flow cytometry,and testicular injury was assessed using hematoxylin and eosin staining to validate the therapeutic effect of WYP in OAZ.Further,serum metabolomics-based analysis was performed using high-performance liquid chromatography-mass spectrometry to identify differential metabolic pathways and possible mechanisms of action of WYP in OAZ treatment.Results:A rat model of OAZ was considered successfully-established after comparing the quality of spermatozoa in the model group to that in the control group.WYP-M and WYP-H treatments significantly improved sperm cell density,motility,and viability compared with those in the model group(all P<.05).Compared with the model group,both WYP-M and WYP-H treatments increased MMP values(P=.006 and P=.021 respectively),while there was no significant difference in the L-carnitine group.L-carnitine and WYP administration reversed damage to the testes to varying degrees compared with that in the model group.Further,44 differential metabolites and four metabolic pathways,especially autophagy pathway,related to OAZ were identified via metabolomics.Conclusions:WYP improves sperm cell quality and MMP in OAZ primarily via autophagy regulation.These findings can be employed to improve the efficacy of WYP in humans.
基金funded by National Natural Science Foundation of China(No.12002392).
文摘Five types of polyurea elastomers were synthesized by changing the isocyanate component and the mechanical properties of polyurea materials were measured. Fiber-reinforced cement boards(FRCB)strengthened by polyurea with different formulations were processed, and a series of experiments were carried out on the specimens with gas explosion devices. The results showed that the conventional mechanical properties of different types of polyureas had their own advantages. Based on the gas explosion overpressure criterion, the blast resistances of reinforced plates were quantitatively evaluated,and the best polyurea was selected to guide the formulation design. The three typical failure modes of polyurea-reinforced FRCBs were flexural, shear, and flexural-shear failure. Dynamic thermodynamics and shock wave spectral analysis revealed that the polyurea did not undergo a glass transition in the gas explosion tests but retained its elastic properties, allowing it to effectively wrap the fragments formed by the brittle substrates.
基金Supported by a grant from the National Natural Sciences Foundation of China(No.81602531)
文摘Objective Long-term cigarette smoke exposure damages the airway epithelium.However,the correlation among GSTM1 gene polymorphism,smoking status,and lung cancer susceptibility remains unclear.This study aimed to identify the genetic polymorphism of GSTM1 and examine the association of GSTM1 polymorphism and smoking history with lung cancer susceptibility.Methods The genetic polymorphism of GSTM1 was genotyped by polymerase chain reaction(PCR) in 217 lung cancer patients and 198 controls.The demographic data and smoking history of the patients were collected.The age,sex,and residence of the two groups were also obtained.Results Significant differences in GSTM1 polymorphism were observed between the case and control groups(P=0.024).Smoking time and smoking index were significantly different between the case and control groups.With the increase in smoking time and smoking index,the differences became more obvious.There was a synergistic effect between GSTM1 and smoking(S=3.35).The risk of developing lung cancer increased 4.82 fold in smokers carrying deficient-type GSTM1.Compared with patients carrying wild-type GSTM1,the risk of developing lung cancer was higher in those carrying deficient-type GSTM1 with the increase in smoking time and smoking index.In different pathological types,no significant differences were observed in GSTM1 polymorphism.In different pathological types,the proportions of patients increased with the increase in smoking time and smoking index,especially the proportion of patients with squamous cell carcinoma.Compared with wild-type GSTM1,the proportion of patients with deficient-type GSTM1 increased with the increase in smoking time and smoking index(P=0.003 and 0.017).This trend was mainly observed in those with squamous cell carcinoma.Conclusion GSTM1 mutation is associated with lung cancer susceptibility.Smokers carrying deficienttype GSTM1 are more likely to develop lung cancer.Compared with patients carrying wild-type GSTM1,smokers with deficient-type GSTM1 are more likely develop lung cancer when smoking time is more than 30 years and smoking index is more than 400.In patients carrying deficient-type GSTM1,the risk of developing squamous cell carcinoma increases with an increase in smoking time and smoking dose.
文摘Objective Platinum-based chemotherapy is the first-line treatment for non-small cell lung cancer,but the chemoresistance of tumor cells continues to be a considerable challenge in the management of NSCLCs,leading to recurrence of most patients.CD133(prominin-1)is a five-transmembrane glycoprotein,and recent evidence suggests that CD133+cells are the cause of drug resistance and tumor recurrence.In this study,the correlation between cisplatin and CD133+cells was investigated systematically.Methods Four lung cancer cell lines,including A549,H460,801D and H1299,were treated with different concentrations of cisplatin.Cell viability was determined by MTT assay.Sphere-forming assay was performed to detect the capability of sphere-forming.CD133+cells was detected by BD FACScaliber flow cytometer.Results The results showed that cisplatin could increase the number of CD133+cells in both time-and dose-dependent manner.The enrichment would weaken but the proportion of CD133+cells was still higher than the basic level as incubation time extended after cisplatin was withdrawn.Compared with adherent culture,the proportion of CD133+cells was higher when the cells were maintained suspension culture.The proportion of CD133+cells significantly increased when cisplatin was provided in suspension culture.Conclusion These results revealed that cisplatin induces the enrichment of CD133+cells and CD133 is a new therapeutic target.Our data partially explained drug resistance to second-line chemotherapy in cisplatin-treated patients with NSCLCs.
文摘Objective: We aimed to examine the expression of cyclooxygenase-2 and the relationship with the pathological types, TNM stage, lymph node metastasis, the degree of differentiation, smoking and the survival. Methods: Immunohistochemical staining method was used to examine the expression of cyclooxygenase-2 of 121 cases of lung cancer and three control groups. The data were statistically analyzed. Results: Compared with the health group, cyclooxygenase-2 was over expressed in the inflammatory tissue(P = 0.036), lung adenocarcinoma(P = 0.005) and squamous carcinoma(P = 0.047). Compared with patients without lymph node metastasis, cyclooxygenase-2 was over expressed(P = 0.033) in patients with lymph node metastasis. Compared with high differentiation group, cyclooxygenase-2 was over expressed(P = 0.004) in low differentiation group. Compared with non-smokers, the expression of cyclooxygenase-2 increased in smokers(P = 0.000). The median survival time of patients that the expression of cyclooxygenase-2 were negative was 9 months(95% CI, 5.6–12.4 months). The median survival time of patients that the expression of cyclooxygenase-2 were positive was 5 months(95% CI, 3–7 months). They was statistical difference(P = 0.001). Conclusion: Overexpression of cyclooxygenase-2 is associated with pathological types, TNM stage, lymph node metastasis, degrees of differentiation, smoking and prognosis in lung cancer.
基金supported by the National Natural Science Foundation of China (61775091, and U2001216)the Shenzhen Key Laboratory Project (ZDSYS201602261933302)+2 种基金Natural Science Foundation of Shenzhen Innovation Committee (JCYJ20180504165851864)the support of Research Grants Council Collaborative Research Fund (RGC- CRF) grant C5037-18GSeed Funding for Strategic Interdisciplinary Research Scheme of the University of Hong Kong and Shenzhen Science and Technology Commission Projects (JCYJ20170818141216288)
文摘Perovskite solar cells(PSCs)commonly exhibit significant performance degradation due to ion migration through the top charge transport layer and ultimately metal electrode corrosion.Here,we demonstrate an interfacial management strategy using a boron chloride subphthalocyanine(Cl_(6)SubPc)/fullerene electron-transport layer,which not only passivates the interfacial defects in the perovskite,but also suppresses halide diffusion as evidenced by multiple techniques,including visual element mapping by electron energy loss spectroscopy.As a result,we obtain inverted PSCs with an efficiency of 22.0%(21.3%certified),shelf life of 7000 h,T_(80) of 816 h under damp heat stress(compared to less than 20 h without Cl_(6)SubPc),and initial performance retention of 98%after 2000 h at 80℃in inert environment,90%after 2034 h of illumination and maximum power point tracking in ambient for encapsulated devices and 95%after 1272 h outdoor testing ISOS-O-1.Our strategy and results pave a new way to move PSCs forward to their potential commercialization solidly.
基金Innovation and Technology Commission of the Hong Kong Special Administrative Region,Grant/Award Number:ITCCNERC14EG03Research Grants Council,University Grants Committee,Grant/Award Numbers:16309418,26206115,HKUST PDFS2021‐4S12,HKUST PDFS2021‐6S08。
文摘The electrochemical reduction reaction of carbon dioxide(CO_(2)RR)is considered to be an effective way to realize carbon neutrality.As a type of intensively studied materials,covalent organic frameworks(COFs)with a tunable pore structure and various functional groups are promising catalysts for CO_(2)RR.Herein,COF synthesized by 2,6‐diaminoanthraquinone and 2,4,6‐triformylphloroglucinol is employed to assist the synthesis of electrocatalysts from Cu single atoms(SAs)to nanoclusters by controlling the electrodeposition.A tandem catalyst for CO_(2)‐to‐CH4 conversion is thus achieved by the Cu nanoclusters dispersed among the isolated Cu SAs in the COF network.It is proposed that CO_(2) is first reduced to CO over the atomically isolated Cu SAs,followed by diffusion onto the neighboring Cu nanoclusters for further reduction into CH4.In addition,mechanistic analysis suggests that the coordinated K^(+)ions on the COF network promote the activation of CO_(2) and the adsorption of reaction intermediates,thus realizing the suppressed hydrogen evolution reaction and selective production of CH4.This study presents a new insight of COFs for the confined synthesis of a tunable SA to nanocluster electrocatalysts,disclosing the great potential of COFs in electrocatalysis.
基金National Natural Science Foundation of China(NSFC grant No.32200462,China)National Natural Science Foundation of China(NSFC grant No.81872021,China)+4 种基金Beijing Municipal Administration of Hospitals Youth Program(grant No.QMS20221603,China)R&D Program of Beijing Municipal Education Commission(grant No.KM202110025004,China)Beijing Natural Science Foundation of China(BJSFC No.7214242,China)Beijing Municipal Administration of Hospitals Incubating Program(grant No.PX2021063,China)Intramural Research Funding Program from Beijing Tuberculosis and Thoracic Tumor Research Institute/Beijing Chest Hospital。
文摘As confusion mounts over RNA isoforms involved in phenotypic plasticity,aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity(ITH).Protease serine 3(PRSS3),possessing four splice variants(PRSS3-SVs;PRSS3-V1—V4),is an indispensable trypsin that shows paradoxical effects on cancer development.Here,we found that PRSS3 transcripts and their isoforms were divergently expressed in lung cancer,exhibiting opposing functions and clinical outcomes,namely,oncogenic PRSS3-V1 and PRSS3-V2 versus tumorsuppressive PRSS3-V3,by targeting different downstream genes.We identified an intragenic CpG island(iCpGI)in PRSS3.Hypermethylation of iCpGI was mediated by UHRF1/DNMT1 complex interference with the binding of myeloid zinc finger 1(MZF1)to regulate PRSS3 transcription.The garlic-derived compound diallyl trisulfide cooperated with 5-aza-2'-deoxycytidine to exert antitumor effects in lung adenocarcinoma cells through site-specific iCpGI demethylation specifically allowing MZF1 to upregulate PRSS3-V3 expression.Epigenetic silencing of PRSS3-V3 via i CpGI methylation(iCpGIm)in BALF and tumor tissues was associated with early clinical progression in patients with lung cancer but not in those with squamous cell carcinoma or inflammatory disease.Thus,UHRF1/DNMT1—MZF1 axismodulated site-specific iCpGIm regulates divergent expression of PRSS3-SVs,conferring nongenetic functional ITH,with implications for early detection of lung cancer and targeted therapies.
基金The research was financially supported by the National Key R&D Program of China(2016YFB0700600)the Guangdong Innovation Team Project(No.2013N080)+2 种基金the Soft Science Research Project of Guangdong Province(No.2017B030301013)the Shenzhen Science and Technology Research Grant(ZDSYS201707281026184)the Shenzhen Peacock Plan(KQTD2014062714543296).
文摘Solar-driven N_(2) fixation using a photocatalyst in water presents a promising alternative to the traditional Haber-Bosch process in terms of both energy efficiency and environmental concern.At present,the product of solar N_(2) fixation is either NH_(4)^(+)or NO_(3)^(-).Few reports described the simultaneous formation of ammonia(NH_(4)^(+))and nitrate(NO_(3)^(-))by a photocatalytic reaction and the related mechanism.In this work,we report a strategy to photocatalytically fix nitrogen through simultaneous reduction and oxidation to produce NH_(4)^(+)and NO_(3)^(-)byW18O49 nanowires in pure water.The underlying mechanism of wavelength-dependent N_(2) fixation in the presence of surface defects is proposed,with an emphasis on oxygen vacancies that not only facilitate the activation and dissociation of N_(2) but also improve light absorption and the separation of the photoexcited carriers.Both NH_(4)^(+)and NO_(3)^(-)can be produced in pure water under a simulated solar light and even till the wavelength reaching 730 nm.The maximum quantum efficiency reaches 9%at 365 nm.Theoretical calculation reveals that disproportionation reaction of the N_(2) molecule is more energetically favorable than either reduction or oxidation alone.It is worth noting that the molar fraction of NH_(4)^(+)in the total product(NH_(4)^(+)plus NO_(3)^(-))shows an inverted volcano shape from 365nm to 730 nm.The increased fraction of NO_(3)^(-)from 365 nm to around 427 nm results from the competition between the oxygen evolution reaction(OER)at W sites without oxygen vacancies and the N_(2) oxidation reaction(NOR)at oxygen vacancy sites,which is driven by the intrinsically delocalized photoexcited holes.From 427nm to 730 nm,NOR is energetically restricted due to its higher equilibrium potential than that of OER,accompanied by the localized photoexcited holes on oxygen vacancies.Full disproportionation of N_(2) is achieved within a range of wavelength from~427nm to~515 nm.This work presents a rational strategy to efficiently utilize the photoexcited carriers and optimize the photocatalyst for practical nitrogen fixation.
基金supported by the National Key Research and Development Project(2022YFA1503900,2022YFA1503000,and 2022YFA1203400)Shenzhen Fundamental Research Funding(JCYJ20210324115809026,JCYJ20220818100212027,and JCYJ20200109141216566)+7 种基金Shenzhen Science and Technology Program(KQTD20190929173815000)Guangdong scientific program with contract no.2019QN01L057Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08C044)to Gu Msupported by the National Natural Science Foundation of China(22033005)to Li Jpartially sponsored by Guangdong Provincial Key Laboratory of Catalysis(2020B121201002).support from Presidential fund and Development and Reform Commission of Shenzhen Municipalitysupported by the Center for Computational Science and Engineering at SUSTechthe CHEM high-performance supercomputer cluster(CHEMHPC)located at the Department of Chemistry,SUSTech。
文摘As an innovative development of single-atom catalysts(SACs),single-cluster catalysts(SCCs)such as dualatom catalysts have attracted considerable interest due to their excellent performance in catalysis.As one of the most powerful and visualizable tools,scanning transmission electron microscopy(STEM)has been widely applied in the characterization of SCCs.Herein,the nitrogen-doped carbonsupported FeFe and CoFe,two representative examples of homonuclear and heteronuclear SCCs,are characterized by STEM.Furthermore,an image processing program is developed to analyze the STEM images and to obtain the locations of atoms,as well as the projected distances between atoms in possible dual-atom pairs.The dimer distances of both CoFe and FeFe catalysts exhibit a trimodal distribution,which can correspond to the energy-favorable atomic structures of the theoretical simulations.Our work offers an avenue for directly revealing the possible atomic configurations of dual-atom sites in SCCs via big data statistics of STEM images and strong theoretical simulations.
基金supported by the National Natural Science Foundation of China(21802065 and 12004156)Shenzhen DRC Project[2018]1433+4 种基金Shenzhen Science and Technology Program(KQTD20190929173815000)ShenzhenBasicResearchFund(JCYJ20190809181601639)Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08C044)The microscopy charaterization was performed at the Pico Center at SUSTech that receives support from the Presidential FundDevelopment and Reform Commission of Shenzhen MunicipalitySUSTech Presidential Postdoctoral Fellowship。
文摘As a promising anode material candidate for sodium-ion batteries,antimony(Sb)has attracted enormous research interest due to its high specific capacity and low sodiation voltage.However,its dramatic volume expansion upon sodiation adversely affects its cycle stability.We have developed an oxidation-coating-reduction strategy for fabricating yolk-shell Sb@C rods from commercially available Sb powder.In particular,the thermal reduction of vaporized Sb_(2)O_(3) generates densely distributed Sb single atoms and clusters on the carbon shell.The sodiation process of the Sb@C sample was recorded through in situ transmission electron microscopy.Irregular expansion of Sb particles was observed,and it was also revealed that the carbon shell could deform with the expanded Sb particles.Beyond the intuitively understood advantage that internal voids can provide space for expansion of internal active materials,the deformability of carbon shells can add further ability to withstand the volume expansion.The two structural merits of the yolk-shell construction enable the Sb@C material to deliver an enhanced cycle performance.Its reversible capacity exceeds 620 mA h g^(−1) at 0.1C,with an initial coulombic efficiency of up to 84.9%,and about 95%of the capacity in the charging voltage profile is delivered below 1.0 V vs.Na+/Na.These performance metrics are very promising for potential practical applications.
基金supported by the National Key R&D Program of China(No.2020YFB1505800)the Guangzhou Key Research and Development Program(No.202103040002)+2 种基金the Green Tech Fund(No.GTF202020092)the National Key R&D Program of China(No.2022YFA1503900)the Guangdong Scientific Program(No.2019QN01L057).
文摘This work presents simple post-treatment methods to selectively and partially remove the Pd core of Pd-Pt core–shell(Pt@Pd/C)catalysts.The proton exchange membrane fuel cell with the post-treated Pt@Pd/C cathode(Pt loading:0.10 mg·cm^(-2))delivers an impressive peak power density of 1.2 W·cm^(-2).The partial removal of Pd core endows an ultrahigh oxygen reduction reaction(ORR)mass activity of 0.32 A·g_(PGM)-1 when normalized to the platinum group metal(PGM)mass,or equivalently 0.55 A·mg_(Pt)^(-1) at 0.9 V measured in a fuel cell.The post-treatment thickens the Pt shells and mitigates the Pd dissolution during potential cycling.As a result,the post-treated core-shell catalyst demonstrates superior durability in ORR mass activity and polarization power density retention than untreated core-shell catalyst and benchmark Pt/C.In-situ inductively coupled plasmamass spectrometry(ICP-MS)results highlight that the amount of dissolved Pd in post-treated core–shell catalyst is 17-times lower than that of the untreated one.Our findings highlight the importance of structural tuning of catalysts in enhancing their mass activity and durability.
文摘Summary of main observation and conclusion Atomistic dynamics of protonated polyglycine,glyn-H^+(n=3,5,and 7),colliding with a fluorinated octanethiol self-assembled monolayer(F-SAM)surface has been studied by trajectory calculations.The effects of peptide size on the collision processes and energy transfer efficiencies are emphasized and discussed in detail.The simulations show that the fraction of trapping,which is related to the soft-landing process,dramatically drops with the in crease in collisi on energy,but gently increases with the peptide size.The average energy transfer to the peptide ion's internal degrees of freedom,AEint,is compared with previous experiments.The limiting probability Po of energy transfer to the surface is given by fitting a function of Poexp(—b/&).Our results suggest that the efficiencies of energy transfer are less dependent on the masses,even the categories of the peptide ions,and are determined by the character of the surfaces.
基金supported by the Natural Science Foundation of Shandong Province(ZR2020ZD10)the National Natural Science Foundation of China(21775142)Shenzhen Natural Science Fund(20200925154115001 and JCYJ20210324115809026).
