Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore...Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore from Yunnan Province, China, was investigated. The results show that free gold and auriferous sulfides account for 94.99 % of total gold. Without adding organic acid in floatation, only 82 % recovery of gold could be obtained.Gold recovery in Au/Pb concentrates increases by 9.29 %with oxalate added and by 7.35 % with citric acid added,respectively, while performances of lead and arsenic nearly keep a constant. A possible reason is that free gold is of wonderful selectivity against pyrite with organic activators.A new method to enhance gold recovery is proposed.展开更多
Supramolecular prodrug vesicles(H-4⊃B-2@MB)with selective antibacterial activity have been successfully constructed.Specifically,a natural antibiotic prodrug(B-2)with glutathione(GSH)-responsiveness was synthesized.Th...Supramolecular prodrug vesicles(H-4⊃B-2@MB)with selective antibacterial activity have been successfully constructed.Specifically,a natural antibiotic prodrug(B-2)with glutathione(GSH)-responsiveness was synthesized.The hydrophobic interaction between B-2 and a novel water-soluble cavitand with deep cavity(H-4)resulted in the formation of a host-vip complex,which further self-assembled into supramolecular vesicles.The formed vesicles could effectively encapsulate the photosensitizer methylene blue(MB),enabling co-delivery of antibiotics and photosensitizers in the presence of GSH.Moreover,upon excitation at 630 nm,the photosensitizers generate reactive oxygen species(ROS),effectively eradicating E.coli through combined chemo-photodynamic therapy.Considering that GSH is predominantly present in Gram-negative bacteria such as E.coli,this strategy exhibits substantial potential for selectively inhibiting bacteria characterized by high GSH levels to regulate bacterial colony equilibrium.展开更多
The activation and selective conversion of energy-related molecules is an important research area of energy chemistry.The depletion of petroleum has stimulated research activities into the utilization of non-petroleum...The activation and selective conversion of energy-related molecules is an important research area of energy chemistry.The depletion of petroleum has stimulated research activities into the utilization of non-petroleum carbon resources such as natural gas(including conventional and展开更多
The loss of rare earths(REs)takes place during the pre-decalcification process of mixed rare earth concentrate.In an effort to reduce such RE loss,a novel idea to improve the leaching selectivity of Ca to REs by apply...The loss of rare earths(REs)takes place during the pre-decalcification process of mixed rare earth concentrate.In an effort to reduce such RE loss,a novel idea to improve the leaching selectivity of Ca to REs by applying selective mechanical activation was proposed.First,regarding the key minerals affecting the leaching selectivity of Ca to REs,the differences in the mechanical activation behaviors of CaF_(2) and REFCO_(3) were studied,and we find that the lattice strain of CaF_(2) increases from 0.21%to 0.42%,whereas that of REFCO_(3) increases from 0.31%to 0.40%.Notably,CaF_(2) demonstrates a larger lattice strain than REFCO_(3),indicating greater mechanical activation energy storage and higher leaching activity.Next,the HCl leaching process was studied.A significant leaching selectivity of Ca to REs,from 21.6 to 35.1,is achieved through mechanical activation.The Ca leaching rate reaches 80.7%when the RE loss is 2.3%in the activated sample.This study provides an novel approach for achieving selective extraction of specific components via mechanical activation pretreatment.展开更多
BACKGROUND Duchenne muscular dystrophy(DMD)is a severe lethal X-linked monogenic recessive congenital muscular dystrophy caused by various types of mutations in the dystrophin gene(DG).It is one of the most common hum...BACKGROUND Duchenne muscular dystrophy(DMD)is a severe lethal X-linked monogenic recessive congenital muscular dystrophy caused by various types of mutations in the dystrophin gene(DG).It is one of the most common human genetic diseases and the most common type of muscular dystrophy,in part because DG is one of the largest protein-coding genes in the human genome with a relatively high risk of being affected by a large palette of mutations.Long-term corticosteroid therapy(LTCT)with deflazacort started at age 4 is the most accessible and used pharmacological therapy for DMD in Romania."Asea®redox supplement"(ARS)is an approved dietary supplement in the European Union.Several studies have shown that it is a very potent selective NRF2 activator,and thus a very potent,albeit indirect,antioxidant,with no toxicity up to high doses,in contrast to LTCT.CASE SUMMARY This paper presents a 3-case series on the effects of ARS in a 4-year-old,5-year-old and 3-year-old boy all with DMD from Bucharest or Slobozia(Romania).This is the first report of this type worldwide.The parents of these boys had refused LTCT.They were treated with relatively high doses of ARS(3-7 mL/kg/day).For two patients,ARS was administered in combination with medium doses of Lcarnitine and omega-3 fatty acids for various intellectual disabilities.Periodic consults and assessments for rhabdomyolysis,medullar and liver toxicity markers(blood count,gamma-glutamyl transferase,aspartate aminotransferase,alanine transaminase,lactate dehydrogenase,creatine kinase,creatine kinase-MB and serum myoglobin)were performed.In vitro studies showed that ARS is a very potent and selective NRF2 activator,and thus a very potent indirect antioxidant.The in vivo studies also support this main pharmacological mechanism of ARS,with no toxicity at high doses,in contrast with much more toxic corticosteroids which are often refused by parents for their children with DMD.Although they were three distinct ages and carried three distinct DG mutations,from the first months of ARS-based treatment,the children responded similarly to ARS.The rhabdomyolysis markers,which were initially very high,significantly dropped,and there was no evidence for medullar and/or hepatic toxicity in any of the 3 patients.CONCLUSIONS ARS has significant indirect antioxidant effects via NRF2 and deserves extensive trials in children with DMD,as an adjuvant to corticoids or as a substitute in DMD patients who refuse corticoids.Future trials should also focus on ARS as an adjuvant in many types of acute/chronic infectious/non-infectious diseases where cellular oxidative stress is involved.展开更多
Osteoarthritis(OA)is a prevalent degenerative joint disorder marked by chronic pain,inflammation,and cartilage loss,with current treatments limited to symptom relief.G protein-coupled receptors(GPCRs)play a pivotal ro...Osteoarthritis(OA)is a prevalent degenerative joint disorder marked by chronic pain,inflammation,and cartilage loss,with current treatments limited to symptom relief.G protein-coupled receptors(GPCRs)play a pivotal role in OA progression by regulating inflammation,chondrocyte survival,and matrix homeostasis.However,their multifaceted signaling,via G proteins orβ-arrestins,poses challenges for precise therapeutic targeting.Biased agonism,where ligands selectively activate specific GPCR pathways,emerges as a promising approach to optimize efficacy and reduce side effects.This review examines biased signaling in OAassociated GPCRs,including cannabinoid receptors(CB1,CB2),chemokine receptors(CCR2,CXCR4),protease-activated receptors(PAR-2),adenosine receptors(A1R,A2AR,A2BR,A3R),melanocortin receptors(MC1R,MC3R),bradykinin receptors(B2R),prostaglandin E2 receptors(EP-2,EP-4),and calcium-sensing receptors(CaSR).We analyze ligands in clinical trials and explore natural products from Traditional Chinese Medicine as potential biased agonists.These compounds,with diverse structures and bioactivities,offer novel therapeutic avenues.By harnessing biased agonism,this review underscores the potential for developing targeted,safer OA therapies that address its complex pathology,bridging molecular insights with clinical translation.展开更多
Hydrogenation catalysts frequently impose a compromise between activity and selectivity,where maximizing one property inevitably diminishes the other.Researchers from the Dalian Institute of Chemical Physics(DICP)of t...Hydrogenation catalysts frequently impose a compromise between activity and selectivity,where maximizing one property inevitably diminishes the other.Researchers from the Dalian Institute of Chemical Physics(DICP)of the Chinese Academy of Sciences,in collaboration with scholars from University of Science and Technology of China and the Karlsruhe Institute of Technology in Germany,cracked this dilemma by engineering bimetallic catalysts with atomic precision-a breakthrough that boosts hydrogenation efficiency by 35-fold while maintaining pinpoint accuracy,resolving the stubborn activity-selectivity paradox.展开更多
Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater.However,the structure of bimetallic has been much less investigated for ...Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater.However,the structure of bimetallic has been much less investigated for catalyst optimization.Herein,two main types of Pd-Cu bimetallic nanocrystal structures,heterostructure and intermetallic,were prepared and characterized using high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The results show that two individual Pd and Cu nanocrystals with a mixed interface exist in the heterostructure nanocrystals,while Pd and Cu atoms are uniformly distributed across the intermetallic Pd-Cu nanocrystals.The catalytic nitrate reduction experiments were carried out in a semibatch reactor under constant hydrogen flow.The nitrate conversion rate of the heterostructure Pd-Cu nanocrystals supported onα-Al_(2)O_(3),γ-Al_(2)O_(3),SBA-15,and XC-72R exhibited 3.82-,6.76-,4.28-,2.44-fold enhancements relative to the intermetallic nanocrystals,and the nitrogen and nitrite were the main products for the heterostructure and intermetallic Pd-Cu nanocrystals,respectively.This indicates that the catalytic nitrate reduction over Pd-Cu catalyst is sensitive to the bimetallic structures of the catalysts,and heterostructure bimetallic nanocrystals exhibit better catalytic performances on both the activity and selectivity,which may provide new insights into the design and optimization of catalysts to improve catalytic activity and selectivity for nitrate reduction in water.展开更多
Pd/C catalysts were prepared by deposited Pd nanoparticles （NPs） on different carbon supports including activated carbon （AC）, graphite oxide （GO）, and reduced graphite oxide （rGO） using sol-immobilization met...Pd/C catalysts were prepared by deposited Pd nanoparticles （NPs） on different carbon supports including activated carbon （AC）, graphite oxide （GO）, and reduced graphite oxide （rGO） using sol-immobilization method. Through transmission electron microscopy, powder X-ray di raction, and X-ray photoelectron spectroscopy, the role of the carbon supports for the catalytic performances of Pd/C catalysts was examined in selective hydrogenation of acetylene. The results indicate that Pd/AC exhibited higher activity and selectivity than Pd/GO and Pd/rGO in the gas phase selective hydrogenation of acetylene. Thermal and chemical treatment of AC supports also have some effect on the catalytic performance of Pd/AC catalysts. The differences in the activity and selectivity of various Pd/C catalysts were partly attributed to the metal-support interaction.展开更多
A new synthetic route to polyamides and hydroxyl polyamides was established, based on the selecting (?)-acylation of three novel typical active diesters: the active diester of N-hydroxy- (?) 4-epoxy-5-cyclohexene-2, 3...A new synthetic route to polyamides and hydroxyl polyamides was established, based on the selecting (?)-acylation of three novel typical active diesters: the active diester of N-hydroxy- (?) 4-epoxy-5-cyclohexene-2, 3-dicarboximide( HOEC), such as N, N'-(temphthaloyldioxy) bis(1, 4- epoxy - 5 - cyclohexene- 2, 3 - dicarboximide.) ( PBOEC), N, N'- ( isophthaloyl - dioxy) bis (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide)(IPBOEC) and N, N' -(adipoyldioxy) his (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide) ( ADOEC)with aliphatic diamines and 1,3-diamino-2-hydroxypropane. The polycondensation occurs at room temperature in solution without added catalyst. Dipolar aprotic solvents which include dimethyl sulfoxide, N- methyl - 2- pyrrolidone and dimethylformamide were used as solvents for polymerization. The selective N-acylation of two active diesters was performed as a model reaction study.展开更多
Based on our previous work,a series of hydrazone moiety-bearing aminopyrimidines were synthesized.The compounds were evaluated for inhibitory activities against EGFRT790M/L858 R and antiproliferative activities agains...Based on our previous work,a series of hydrazone moiety-bearing aminopyrimidines were synthesized.The compounds were evaluated for inhibitory activities against EGFRT790M/L858 R and antiproliferative activities against H1975 and A549 NSCLC cell lines harboring different forms of EGFR.Compounds 7f and7 k exhibited potent and selective activity in inhibition of gefitinib-resistant H1975 cancer cells（IC50;0.45,0.2μmol/L） while were much less active on A549 cancer cells（IC50;52.83,〉100μmol/L）.Both compounds could be served as promising lead compounds for further investigation.展开更多
In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- ti...In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.展开更多
A precise localization for mobile target in wireless sensor networks is presented in this letter,where a geometrical relationship is explored to improve the location estimation for mobile target,in-stead of a simple c...A precise localization for mobile target in wireless sensor networks is presented in this letter,where a geometrical relationship is explored to improve the location estimation for mobile target,in-stead of a simple centroid approach.The equations of location compensation algorithm for mobiletarget are derived based on linear trajectory prediction and sensor selective activation.The resultsbased on extensive simulation experiments show that the compensation algorithm gets better per-formance in metrics of quality of tracking and energy efficiency with the change of sensor sensing range,the ratio of sensing range and sensor activation range,and the data sampling rate than traditionalmethods,which means our proposing can achieve better quality-energy tradeoff for mobile target inwireless sensor networks.展开更多
Effects of vanadium on light olefins selectivity of FCC catalysts were investigated with vanadium having different oxidation numbers （hereinafter abbreviated as Oxnum）. Molecular modeling studies showed that vanadiu...Effects of vanadium on light olefins selectivity of FCC catalysts were investigated with vanadium having different oxidation numbers （hereinafter abbreviated as Oxnum）. Molecular modeling studies showed that vanadium with low Oxnum could affect the chemical conversion of large-size hydrocarbon molecules. However, the vanadium deposited on equilibrium catalyst bad high Oxnum because of the oxidation reaction taking place in the regenerator, so an activation method to reduce vanadium Oxnum named ＂selective activation＂ was introduced. It was proved by means of Electron Paramagnetic Resonance （EPR） and Temperature-Programmed Reduction （TPR） methods that the vanadium Oxnum was decreased, when the catalyst was activated. The molecular modeling studies are consistent well with the lab evaluation results. The light olefins selectivity of activated equilibrium catalysts was better than that achieved by the inactivated catalysts. Similar results were observed with the lab vanadium-contaminated catalyst. The light olefins selectivity of the catalyst was optimized when the vanadium Oxnum was close to 2 （VO）.展开更多
Surface properties （viz. surface area, basicity/base strength distribution, and crystal phases） of alkali metal doped CaO （alkali metal/Ca= 0.1 and 0.4） catalysts and their catalytic activity/selectivity in oxidat...Surface properties （viz. surface area, basicity/base strength distribution, and crystal phases） of alkali metal doped CaO （alkali metal/Ca= 0.1 and 0.4） catalysts and their catalytic activity/selectivity in oxidative coupling of methane （OCM） to higher hydrocarbons at different reaction conditions （viz. temperature, 700 and 750 ℃; CH4/O2 ratio, 4.0 and 8.0 and space velocity, 5140-20550 cm^3 ·g^-1·h^-1） have been investigated. The influence of catalyst calcination temperature on the activity/selectivity has also been investigated. The surface properties （viz. surface area, basicity/base strength distribution） and catalytic activity/selectivity of the alkali metal doped CaO catalysts are strongly influenced by the alkali metal promoter and its concentration in the alkali metal doped CaO catalysts. An addition of alkali metal promoter to CaO results in a large decrease in the surface area but a large increase in the surface basicity （strong basic sites） and the C2＋ selectivity and yield of the catalysts in the OCM process. The activity and selectivity are strongly influenced by the catalyst calcination temperature. No direct relationship between surface basicity and catalytic activity/selectivity has been observed. Among the alkali metal doped CaO catalysts, Na-CaO （Na/Ca = 0.1, before calcination） catalyst （calcined at 750 ℃）, showed best performance （C2＋ selectivity of 68.8% with 24.7% methane conversion）, whereas the poorest performance was shown by the Rb-CaO catalyst in the OCM process.展开更多
We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and exa- mine the effect of introducing cross inhibition between the motivations for the two activities. While ...We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and exa- mine the effect of introducing cross inhibition between the motivations for the two activities. While cross-inhibition has pre- viously been included in models of decision making, the question of what benefit it may provide to an animal＇s activity selection behaviour has not previously been studied. In neuroscience and in collective behaviour cross-inhibition, and other equivalent means of coupling evidence-accumulating pathways, have been shown to approximate statistically-optimal decision-making and to adaptively break deadlock, thereby improving decision performance. Switching between activities is an ongoing decision process yet here we also find that cross-inhibition robustly improves its efficiency, by reducing the frequency of costly switches between behaviours .展开更多
The carbon–carbon couplings of 4,4＇＇-dibromo-p-terphenyl（DBTP） on Cu（110） surface have been investigated at a single molecular level by scanning tunneling microscopy. After annealing at 353 K, a mixture of para...The carbon–carbon couplings of 4,4＇＇-dibromo-p-terphenyl（DBTP） on Cu（110） surface have been investigated at a single molecular level by scanning tunneling microscopy. After annealing at 353 K, a mixture of parallel non-organometallic and organometallic intermediates of DBTP molecules along the[1–10] direction of the surface has been observed. Further annealing at 393 K causes one group of molecules to form oligomers with para-para and para-meta motifs via Ullmann reaction and the other group of molecules to synthesize oligomers with meta-meta motifs via direct carbon–carbon coupling reaction. Statistical results directly reveal that the occurrence of reaction type is strongly related to the initial binding configuration of DBTP molecules.展开更多
It is of great interest to develop the novel transition metal-based electrocatalysts with high selectivity and activity for two electron oxygen reduction reaction(2e^(-) ORR).Herein,the nickel ditelluride(NiTe_(2)) wi...It is of great interest to develop the novel transition metal-based electrocatalysts with high selectivity and activity for two electron oxygen reduction reaction(2e^(-) ORR).Herein,the nickel ditelluride(NiTe_(2)) with layered structure was explored as the 2e^(-) ORR electrocatalyst,which not only showed the highest 2e^(-) selectivity more than 97%,but also delivered a slight activity decay after 5000 cycles in alkaline media.Moreover,when NiTe_(2) was assembled as the electrocatalyst in H-type electrolyzer,the on-site yield of H_(2)O_(2) could reach up to 672 mmol h^(-1)g^(-1) under 0.45 V vs.RHE.Further in situ Raman spectra,theoretical calculation and post microstructural analysis synergistically unveiled that such a good 2e^(-) ORR performance could be credited to the intrinsic layered crystal structure,the high compositional stability,as well as the electron modulation on the active site Ni atoms by neighboring Te atoms,leading to the exposure of active sites as well as the optimized adsorption free energy of Ni to –OOH.More inspiringly,such telluride electrocatalyst has also been demonstrated to exhibit high activity and selectivity towards 2e^(-) ORR in neutral media.展开更多
Drug therapy,including chemotherapy and immunotherapy,remains a cornerstone of cancer treatment;however,significant toxic side effects are often unavoidable,inhibiting tumor growth while causing damage to multiple org...Drug therapy,including chemotherapy and immunotherapy,remains a cornerstone of cancer treatment;however,significant toxic side effects are often unavoidable,inhibiting tumor growth while causing damage to multiple organ systems.Polymeric nanomedicines have shown substantial promise in addressing the limitations of small-molecule drugs,such as poor solubility,rapid clearance,low tumor retention,and adverse effects,thereby enhancing the therapeutic index.Despite these advances,clinical outcomes indicate that the overall survival rates of cancer patients post-treatment are often not significantly higher than those achieved with standard small-molecule drugs.This is largely due to the inadequate tumor targeting and limited tumor penetration of polymeric drugs despite their drug release and targeting capabilities.While actively tumor-targeted and selectively activated drug strategies can potentially improve drug targeting,traditional approaches have yielded unsatisfactory results due to insufficient differences in targets,such as markers and stimuli,between tumor and normal tissues.Recent innovations focus on utilizing drug or external stimuli,such as light,radiation,and ultrasound,to amplify tumor-associated markers or stimuli,enabling more precise tumor targeting and selective drug activation.Based on these innovations,actively targeted or selectively activated polymeric nanomedicines can further enhance drug accumulation within tumors and improve therapeutic outcomes.Moreover,the integration of actively tumor-targeting and tumor-selectively activated strategies represents a significant advancement,which achieves simultaneously enhanced drug accumulation and selective activation within the tumors.This review highlights the significant potential,challenges,and advanced strategies of polymeric nanomedicines in targeted tumor therapy,emphasizing the need for ongoing research to optimize their effectiveness and ultimately improve patient outcomes,paving the way for more effective and less toxic cancer treatment options.展开更多
The reactivation and subsequent reuse of exhausted selective catalytic reduction(SCR)catalysts has significant economic and environmental advantages.Water and acid washing along with thermal regeneration are commonly ...The reactivation and subsequent reuse of exhausted selective catalytic reduction(SCR)catalysts has significant economic and environmental advantages.Water and acid washing along with thermal regeneration are commonly used to eliminate toxic substances from the catalyst surface,while these processes often result in the undesired loss of active components.In this research,an impregnation approach was adopted to replenish the depleted active constituents of the spent V_(2)O_(5)-WO_(3)/TiO_(2)(VW/Ti)catalyst.Experimental investigations were conducted to evaluate the influence of Ce/P doping on both the SCR activity of this rejuvenated catalyst and its resistance to the detrimental effects of SO_(2)/H_(2)O exposure.The optimal performance is achieved with the Ce/P co-doped VW/Ti catalyst,demonstrating remarkable efficiency in removing nearly 100%of NO_(x)across a broad range of temperatures from 150 to 450℃.The incorporation of a proper content of Ce serves to increase the VOx surface density from a sub-monolayer state to a monolayer state and fosters the formation of more surface oxygen vacancies.This transformation positively contributes to enhancing both the catalytic activity and the resistance to SO_(2)/H_(2)O poisoning.Further treatment with H3PO4,although rendering the catalyst more susceptible to H_(2)O,achieves a delicate balance between its surface acidity and redox capabilities.This optimized state not only enhances the catalyst's robustness but also further widens the active temperature window.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51374247)
文摘Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore from Yunnan Province, China, was investigated. The results show that free gold and auriferous sulfides account for 94.99 % of total gold. Without adding organic acid in floatation, only 82 % recovery of gold could be obtained.Gold recovery in Au/Pb concentrates increases by 9.29 %with oxalate added and by 7.35 % with citric acid added,respectively, while performances of lead and arsenic nearly keep a constant. A possible reason is that free gold is of wonderful selectivity against pyrite with organic activators.A new method to enhance gold recovery is proposed.
基金supported by the National Natural Science Foundation of China(No.22271154)Natural Science Foundation of Jiangsu Province(No.BK20211179)+3 种基金Innovation Support Program of Jiangsu Province(No.BZ2023055)Fundamental Research Funds for the Central Universities(No.NS2023033)China Postdoctoral Science Foundation(No.2023M731658)Achievement Transformation Project of Qinghai Province(No.2021-SF-145).
文摘Supramolecular prodrug vesicles(H-4⊃B-2@MB)with selective antibacterial activity have been successfully constructed.Specifically,a natural antibiotic prodrug(B-2)with glutathione(GSH)-responsiveness was synthesized.The hydrophobic interaction between B-2 and a novel water-soluble cavitand with deep cavity(H-4)resulted in the formation of a host-vip complex,which further self-assembled into supramolecular vesicles.The formed vesicles could effectively encapsulate the photosensitizer methylene blue(MB),enabling co-delivery of antibiotics and photosensitizers in the presence of GSH.Moreover,upon excitation at 630 nm,the photosensitizers generate reactive oxygen species(ROS),effectively eradicating E.coli through combined chemo-photodynamic therapy.Considering that GSH is predominantly present in Gram-negative bacteria such as E.coli,this strategy exhibits substantial potential for selectively inhibiting bacteria characterized by high GSH levels to regulate bacterial colony equilibrium.
文摘The activation and selective conversion of energy-related molecules is an important research area of energy chemistry.The depletion of petroleum has stimulated research activities into the utilization of non-petroleum carbon resources such as natural gas(including conventional and
基金Project supported by the National Natural Science Foundation of China(52004252)Natural Science Foundation ofHenan Province(222300420548)Strategic Research and Consulting Project of Chinese Academy of Engineering(2022-XBZD-07)。
文摘The loss of rare earths(REs)takes place during the pre-decalcification process of mixed rare earth concentrate.In an effort to reduce such RE loss,a novel idea to improve the leaching selectivity of Ca to REs by applying selective mechanical activation was proposed.First,regarding the key minerals affecting the leaching selectivity of Ca to REs,the differences in the mechanical activation behaviors of CaF_(2) and REFCO_(3) were studied,and we find that the lattice strain of CaF_(2) increases from 0.21%to 0.42%,whereas that of REFCO_(3) increases from 0.31%to 0.40%.Notably,CaF_(2) demonstrates a larger lattice strain than REFCO_(3),indicating greater mechanical activation energy storage and higher leaching activity.Next,the HCl leaching process was studied.A significant leaching selectivity of Ca to REs,from 21.6 to 35.1,is achieved through mechanical activation.The Ca leaching rate reaches 80.7%when the RE loss is 2.3%in the activated sample.This study provides an novel approach for achieving selective extraction of specific components via mechanical activation pretreatment.
文摘BACKGROUND Duchenne muscular dystrophy(DMD)is a severe lethal X-linked monogenic recessive congenital muscular dystrophy caused by various types of mutations in the dystrophin gene(DG).It is one of the most common human genetic diseases and the most common type of muscular dystrophy,in part because DG is one of the largest protein-coding genes in the human genome with a relatively high risk of being affected by a large palette of mutations.Long-term corticosteroid therapy(LTCT)with deflazacort started at age 4 is the most accessible and used pharmacological therapy for DMD in Romania."Asea®redox supplement"(ARS)is an approved dietary supplement in the European Union.Several studies have shown that it is a very potent selective NRF2 activator,and thus a very potent,albeit indirect,antioxidant,with no toxicity up to high doses,in contrast to LTCT.CASE SUMMARY This paper presents a 3-case series on the effects of ARS in a 4-year-old,5-year-old and 3-year-old boy all with DMD from Bucharest or Slobozia(Romania).This is the first report of this type worldwide.The parents of these boys had refused LTCT.They were treated with relatively high doses of ARS(3-7 mL/kg/day).For two patients,ARS was administered in combination with medium doses of Lcarnitine and omega-3 fatty acids for various intellectual disabilities.Periodic consults and assessments for rhabdomyolysis,medullar and liver toxicity markers(blood count,gamma-glutamyl transferase,aspartate aminotransferase,alanine transaminase,lactate dehydrogenase,creatine kinase,creatine kinase-MB and serum myoglobin)were performed.In vitro studies showed that ARS is a very potent and selective NRF2 activator,and thus a very potent indirect antioxidant.The in vivo studies also support this main pharmacological mechanism of ARS,with no toxicity at high doses,in contrast with much more toxic corticosteroids which are often refused by parents for their children with DMD.Although they were three distinct ages and carried three distinct DG mutations,from the first months of ARS-based treatment,the children responded similarly to ARS.The rhabdomyolysis markers,which were initially very high,significantly dropped,and there was no evidence for medullar and/or hepatic toxicity in any of the 3 patients.CONCLUSIONS ARS has significant indirect antioxidant effects via NRF2 and deserves extensive trials in children with DMD,as an adjuvant to corticoids or as a substitute in DMD patients who refuse corticoids.Future trials should also focus on ARS as an adjuvant in many types of acute/chronic infectious/non-infectious diseases where cellular oxidative stress is involved.
基金supported by the National Key R&D Program of the Ministry of Science and Technology(2023YFC2509900)National Natural Science Foundation of China(82374106)+3 种基金National Natural Science Foundation of China(U22A20371)the Basic and Applied Basic Research Fund of Guangdong Province(2021B1515120061)the Shenzhen Science and Technology Innovation Committee(JCYJ20210324102006017)SZ-HK Joint Laboratory for Innovative Biomaterials under CAS-HK Joint Laboratories(2024-2028).
文摘Osteoarthritis(OA)is a prevalent degenerative joint disorder marked by chronic pain,inflammation,and cartilage loss,with current treatments limited to symptom relief.G protein-coupled receptors(GPCRs)play a pivotal role in OA progression by regulating inflammation,chondrocyte survival,and matrix homeostasis.However,their multifaceted signaling,via G proteins orβ-arrestins,poses challenges for precise therapeutic targeting.Biased agonism,where ligands selectively activate specific GPCR pathways,emerges as a promising approach to optimize efficacy and reduce side effects.This review examines biased signaling in OAassociated GPCRs,including cannabinoid receptors(CB1,CB2),chemokine receptors(CCR2,CXCR4),protease-activated receptors(PAR-2),adenosine receptors(A1R,A2AR,A2BR,A3R),melanocortin receptors(MC1R,MC3R),bradykinin receptors(B2R),prostaglandin E2 receptors(EP-2,EP-4),and calcium-sensing receptors(CaSR).We analyze ligands in clinical trials and explore natural products from Traditional Chinese Medicine as potential biased agonists.These compounds,with diverse structures and bioactivities,offer novel therapeutic avenues.By harnessing biased agonism,this review underscores the potential for developing targeted,safer OA therapies that address its complex pathology,bridging molecular insights with clinical translation.
文摘Hydrogenation catalysts frequently impose a compromise between activity and selectivity,where maximizing one property inevitably diminishes the other.Researchers from the Dalian Institute of Chemical Physics(DICP)of the Chinese Academy of Sciences,in collaboration with scholars from University of Science and Technology of China and the Karlsruhe Institute of Technology in Germany,cracked this dilemma by engineering bimetallic catalysts with atomic precision-a breakthrough that boosts hydrogenation efficiency by 35-fold while maintaining pinpoint accuracy,resolving the stubborn activity-selectivity paradox.
基金support from the National Natural Science Foundation of China(Nos.52370100,52000146,and 51978098)China Postdoctoral Science Foundation(No.2020M673351).
文摘Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater.However,the structure of bimetallic has been much less investigated for catalyst optimization.Herein,two main types of Pd-Cu bimetallic nanocrystal structures,heterostructure and intermetallic,were prepared and characterized using high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The results show that two individual Pd and Cu nanocrystals with a mixed interface exist in the heterostructure nanocrystals,while Pd and Cu atoms are uniformly distributed across the intermetallic Pd-Cu nanocrystals.The catalytic nitrate reduction experiments were carried out in a semibatch reactor under constant hydrogen flow.The nitrate conversion rate of the heterostructure Pd-Cu nanocrystals supported onα-Al_(2)O_(3),γ-Al_(2)O_(3),SBA-15,and XC-72R exhibited 3.82-,6.76-,4.28-,2.44-fold enhancements relative to the intermetallic nanocrystals,and the nitrogen and nitrite were the main products for the heterostructure and intermetallic Pd-Cu nanocrystals,respectively.This indicates that the catalytic nitrate reduction over Pd-Cu catalyst is sensitive to the bimetallic structures of the catalysts,and heterostructure bimetallic nanocrystals exhibit better catalytic performances on both the activity and selectivity,which may provide new insights into the design and optimization of catalysts to improve catalytic activity and selectivity for nitrate reduction in water.
文摘Pd/C catalysts were prepared by deposited Pd nanoparticles （NPs） on different carbon supports including activated carbon （AC）, graphite oxide （GO）, and reduced graphite oxide （rGO） using sol-immobilization method. Through transmission electron microscopy, powder X-ray di raction, and X-ray photoelectron spectroscopy, the role of the carbon supports for the catalytic performances of Pd/C catalysts was examined in selective hydrogenation of acetylene. The results indicate that Pd/AC exhibited higher activity and selectivity than Pd/GO and Pd/rGO in the gas phase selective hydrogenation of acetylene. Thermal and chemical treatment of AC supports also have some effect on the catalytic performance of Pd/AC catalysts. The differences in the activity and selectivity of various Pd/C catalysts were partly attributed to the metal-support interaction.
文摘A new synthetic route to polyamides and hydroxyl polyamides was established, based on the selecting (?)-acylation of three novel typical active diesters: the active diester of N-hydroxy- (?) 4-epoxy-5-cyclohexene-2, 3-dicarboximide( HOEC), such as N, N'-(temphthaloyldioxy) bis(1, 4- epoxy - 5 - cyclohexene- 2, 3 - dicarboximide.) ( PBOEC), N, N'- ( isophthaloyl - dioxy) bis (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide)(IPBOEC) and N, N' -(adipoyldioxy) his (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide) ( ADOEC)with aliphatic diamines and 1,3-diamino-2-hydroxypropane. The polycondensation occurs at room temperature in solution without added catalyst. Dipolar aprotic solvents which include dimethyl sulfoxide, N- methyl - 2- pyrrolidone and dimethylformamide were used as solvents for polymerization. The selective N-acylation of two active diesters was performed as a model reaction study.
基金supported by grants from Science Foundation of Shenyang Pharmaceutical University(No.QNJJ2014502)
文摘Based on our previous work,a series of hydrazone moiety-bearing aminopyrimidines were synthesized.The compounds were evaluated for inhibitory activities against EGFRT790M/L858 R and antiproliferative activities against H1975 and A549 NSCLC cell lines harboring different forms of EGFR.Compounds 7f and7 k exhibited potent and selective activity in inhibition of gefitinib-resistant H1975 cancer cells（IC50;0.45,0.2μmol/L） while were much less active on A549 cancer cells（IC50;52.83,〉100μmol/L）.Both compounds could be served as promising lead compounds for further investigation.
文摘In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.
基金the Joint Funds of Guangdong-NSFC(U0735003)the National Natural Science Foundation of China(No.60604029,60702081)+2 种基金the Natural ScienceFoundation of Zhejiang Province(No.Y106384)the Sci-ence and Technology Project of Zhejiang Province(No.2007C31038)and the Scientific Research Fund of Zhejiang Provincial Education(No.20061345).
文摘A precise localization for mobile target in wireless sensor networks is presented in this letter,where a geometrical relationship is explored to improve the location estimation for mobile target,in-stead of a simple centroid approach.The equations of location compensation algorithm for mobiletarget are derived based on linear trajectory prediction and sensor selective activation.The resultsbased on extensive simulation experiments show that the compensation algorithm gets better per-formance in metrics of quality of tracking and energy efficiency with the change of sensor sensing range,the ratio of sensing range and sensor activation range,and the data sampling rate than traditionalmethods,which means our proposing can achieve better quality-energy tradeoff for mobile target inwireless sensor networks.
文摘Effects of vanadium on light olefins selectivity of FCC catalysts were investigated with vanadium having different oxidation numbers （hereinafter abbreviated as Oxnum）. Molecular modeling studies showed that vanadium with low Oxnum could affect the chemical conversion of large-size hydrocarbon molecules. However, the vanadium deposited on equilibrium catalyst bad high Oxnum because of the oxidation reaction taking place in the regenerator, so an activation method to reduce vanadium Oxnum named ＂selective activation＂ was introduced. It was proved by means of Electron Paramagnetic Resonance （EPR） and Temperature-Programmed Reduction （TPR） methods that the vanadium Oxnum was decreased, when the catalyst was activated. The molecular modeling studies are consistent well with the lab evaluation results. The light olefins selectivity of activated equilibrium catalysts was better than that achieved by the inactivated catalysts. Similar results were observed with the lab vanadium-contaminated catalyst. The light olefins selectivity of the catalyst was optimized when the vanadium Oxnum was close to 2 （VO）.
文摘Surface properties （viz. surface area, basicity/base strength distribution, and crystal phases） of alkali metal doped CaO （alkali metal/Ca= 0.1 and 0.4） catalysts and their catalytic activity/selectivity in oxidative coupling of methane （OCM） to higher hydrocarbons at different reaction conditions （viz. temperature, 700 and 750 ℃; CH4/O2 ratio, 4.0 and 8.0 and space velocity, 5140-20550 cm^3 ·g^-1·h^-1） have been investigated. The influence of catalyst calcination temperature on the activity/selectivity has also been investigated. The surface properties （viz. surface area, basicity/base strength distribution） and catalytic activity/selectivity of the alkali metal doped CaO catalysts are strongly influenced by the alkali metal promoter and its concentration in the alkali metal doped CaO catalysts. An addition of alkali metal promoter to CaO results in a large decrease in the surface area but a large increase in the surface basicity （strong basic sites） and the C2＋ selectivity and yield of the catalysts in the OCM process. The activity and selectivity are strongly influenced by the catalyst calcination temperature. No direct relationship between surface basicity and catalytic activity/selectivity has been observed. Among the alkali metal doped CaO catalysts, Na-CaO （Na/Ca = 0.1, before calcination） catalyst （calcined at 750 ℃）, showed best performance （C2＋ selectivity of 68.8% with 24.7% methane conversion）, whereas the poorest performance was shown by the Rb-CaO catalyst in the OCM process.
文摘We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and exa- mine the effect of introducing cross inhibition between the motivations for the two activities. While cross-inhibition has pre- viously been included in models of decision making, the question of what benefit it may provide to an animal＇s activity selection behaviour has not previously been studied. In neuroscience and in collective behaviour cross-inhibition, and other equivalent means of coupling evidence-accumulating pathways, have been shown to approximate statistically-optimal decision-making and to adaptively break deadlock, thereby improving decision performance. Switching between activities is an ongoing decision process yet here we also find that cross-inhibition robustly improves its efficiency, by reducing the frequency of costly switches between behaviours .
基金financially supported by Natural Science Foundation of China (Nos. 61474059, U1432129 and 11504158)National Key Basic Research Program of China (No. 2013CB934200)
文摘The carbon–carbon couplings of 4,4＇＇-dibromo-p-terphenyl（DBTP） on Cu（110） surface have been investigated at a single molecular level by scanning tunneling microscopy. After annealing at 353 K, a mixture of parallel non-organometallic and organometallic intermediates of DBTP molecules along the[1–10] direction of the surface has been observed. Further annealing at 393 K causes one group of molecules to form oligomers with para-para and para-meta motifs via Ullmann reaction and the other group of molecules to synthesize oligomers with meta-meta motifs via direct carbon–carbon coupling reaction. Statistical results directly reveal that the occurrence of reaction type is strongly related to the initial binding configuration of DBTP molecules.
基金supported by the National MCF Energy R&D Program of China (2018YFE0306105)the National Key R&D Program of China (2020YFA0406104, 2020YFA0406101)+8 种基金the Innovative Research Group Project of the National Natural Science Foundation of China (51821002)the National Natural Science Foundation of China (52201269, 52302296, 51972216)the Natural Science Foundation of Jiangsu Province (BK20220028, BK20210735)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province (21KJB430043)the Collaborative Innovation Center of Suzhou Nano Science & Technology, the 111 Projectthe Suzhou Key Laboratory of Functional Nano & Soft Materials, the Jiangsu Key Laboratory for Advanced Negative Carbon Technologiesthe Science and Technology Development Fund, Macao SAR (0009/2022/ITP)the funding from Gusu leading talent plan for scientific and technological innovation and entrepreneurship (ZXL2022487)China Scholarship Council (CSC) for the Ph.D. fellowship。
文摘It is of great interest to develop the novel transition metal-based electrocatalysts with high selectivity and activity for two electron oxygen reduction reaction(2e^(-) ORR).Herein,the nickel ditelluride(NiTe_(2)) with layered structure was explored as the 2e^(-) ORR electrocatalyst,which not only showed the highest 2e^(-) selectivity more than 97%,but also delivered a slight activity decay after 5000 cycles in alkaline media.Moreover,when NiTe_(2) was assembled as the electrocatalyst in H-type electrolyzer,the on-site yield of H_(2)O_(2) could reach up to 672 mmol h^(-1)g^(-1) under 0.45 V vs.RHE.Further in situ Raman spectra,theoretical calculation and post microstructural analysis synergistically unveiled that such a good 2e^(-) ORR performance could be credited to the intrinsic layered crystal structure,the high compositional stability,as well as the electron modulation on the active site Ni atoms by neighboring Te atoms,leading to the exposure of active sites as well as the optimized adsorption free energy of Ni to –OOH.More inspiringly,such telluride electrocatalyst has also been demonstrated to exhibit high activity and selectivity towards 2e^(-) ORR in neutral media.
基金supported by the National Key R&D Program of China(2022YFE0110200)the National Natural Science Foundation of China(52273157,52073279,52025035)+1 种基金the Department of Science and Technology of Jilin Province(20240305041YY)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022224).
文摘Drug therapy,including chemotherapy and immunotherapy,remains a cornerstone of cancer treatment;however,significant toxic side effects are often unavoidable,inhibiting tumor growth while causing damage to multiple organ systems.Polymeric nanomedicines have shown substantial promise in addressing the limitations of small-molecule drugs,such as poor solubility,rapid clearance,low tumor retention,and adverse effects,thereby enhancing the therapeutic index.Despite these advances,clinical outcomes indicate that the overall survival rates of cancer patients post-treatment are often not significantly higher than those achieved with standard small-molecule drugs.This is largely due to the inadequate tumor targeting and limited tumor penetration of polymeric drugs despite their drug release and targeting capabilities.While actively tumor-targeted and selectively activated drug strategies can potentially improve drug targeting,traditional approaches have yielded unsatisfactory results due to insufficient differences in targets,such as markers and stimuli,between tumor and normal tissues.Recent innovations focus on utilizing drug or external stimuli,such as light,radiation,and ultrasound,to amplify tumor-associated markers or stimuli,enabling more precise tumor targeting and selective drug activation.Based on these innovations,actively targeted or selectively activated polymeric nanomedicines can further enhance drug accumulation within tumors and improve therapeutic outcomes.Moreover,the integration of actively tumor-targeting and tumor-selectively activated strategies represents a significant advancement,which achieves simultaneously enhanced drug accumulation and selective activation within the tumors.This review highlights the significant potential,challenges,and advanced strategies of polymeric nanomedicines in targeted tumor therapy,emphasizing the need for ongoing research to optimize their effectiveness and ultimately improve patient outcomes,paving the way for more effective and less toxic cancer treatment options.
基金funded by the Shanghai Committee of Science and Technology(No.23010503500).
文摘The reactivation and subsequent reuse of exhausted selective catalytic reduction(SCR)catalysts has significant economic and environmental advantages.Water and acid washing along with thermal regeneration are commonly used to eliminate toxic substances from the catalyst surface,while these processes often result in the undesired loss of active components.In this research,an impregnation approach was adopted to replenish the depleted active constituents of the spent V_(2)O_(5)-WO_(3)/TiO_(2)(VW/Ti)catalyst.Experimental investigations were conducted to evaluate the influence of Ce/P doping on both the SCR activity of this rejuvenated catalyst and its resistance to the detrimental effects of SO_(2)/H_(2)O exposure.The optimal performance is achieved with the Ce/P co-doped VW/Ti catalyst,demonstrating remarkable efficiency in removing nearly 100%of NO_(x)across a broad range of temperatures from 150 to 450℃.The incorporation of a proper content of Ce serves to increase the VOx surface density from a sub-monolayer state to a monolayer state and fosters the formation of more surface oxygen vacancies.This transformation positively contributes to enhancing both the catalytic activity and the resistance to SO_(2)/H_(2)O poisoning.Further treatment with H3PO4,although rendering the catalyst more susceptible to H_(2)O,achieves a delicate balance between its surface acidity and redox capabilities.This optimized state not only enhances the catalyst's robustness but also further widens the active temperature window.
