Background: Complications after endoscopic retrieval of kidney and ureter stones are obviously related to the size of the stones as well as the experience of the surgeon and other factors. During the procedure it is s...Background: Complications after endoscopic retrieval of kidney and ureter stones are obviously related to the size of the stones as well as the experience of the surgeon and other factors. During the procedure it is sometimes difficult for surgeons to estimate stone size and therefore give prognostic advises. The visual perception of the stone size depends on the shape, colour, distance to the renoscope and dilatation of the ureter. This is the so-called binding problem, because shape, color and direction of motion are processed separately by different population of optical neurons. In order to establish a better prognostic rational especially for less experienced surgeons, we established an intra operative semi-quantitative measurement of the stone size supported by a stone basket. Materials and Methods: We modified the tipped, nitinol stone baskets from the company Urotech with diameters of 2.5, 3.0 and 4 FR. The handle of this basket has a spring mechanism, which automatically closes the basket and provides a predefined fixation force of the stones within the basket. On the handle we established a non-linear scale in mm by grabbing standardized balls or standardized screws. Result: The scales are nonlinear because of the nonlinear relation between the diameter of the stone and the distance of the slider. Also the scales differ in between the basket size, because of the different strain conditions due to the different wire sizes and materials or the spring and basket. Conclusion: This scale could be an important orientation for a surgeon during endourological procedures to estimate stone sizes. After further clinical experience a semi-quantitative visualization like green, yellow and red colors could help to predict potential complications due to large stone sizes. Finally it could bevery interesting for other disciplines like gastroenterology.展开更多
Laparoscopic totally extraperitoneal (TEP) hernia repair is a well-accepted technique for inguinal hernia repair. Different types of mesh and fixation methods have been described. Recently, a novel, self-fixating mesh...Laparoscopic totally extraperitoneal (TEP) hernia repair is a well-accepted technique for inguinal hernia repair. Different types of mesh and fixation methods have been described. Recently, a novel, self-fixating mesh has been introduced and used successfully in open inguinal hernia repairs. We report the first initial experience using this mesh for TEP repairs.展开更多
Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.C...Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.展开更多
Plant synthetic biology has emerged as a transformative field in agriculture,offering innovative solutions to enhance food security,provide resilience to climate change,and transition to sustainable farming practices....Plant synthetic biology has emerged as a transformative field in agriculture,offering innovative solutions to enhance food security,provide resilience to climate change,and transition to sustainable farming practices.By integrating advanced genetic tools,computational modeling,and systems biology,researchers can precisely modify plant genomes to enhance traits such as yield,stress tolerance,and nutrient use efficiency.The ability to design plants with specific characteristics tailored to diverse environmental conditions and agricultural needs holds great potential to address global food security challenges.Here,we highlight recent advancements and applications of plant synthetic biology in agriculture,focusing on key areas such as photosynthetic efficiency,nitrogen fixation,drought tolerance,pathogen resistance,nutrient use efficiency,biofortification,climate resilience,microbiology engineering,synthetic plant genomes,and the integration of artificial intelligence with synthetic biology.These innovations aim to maximize resource use efficiency,reduce reliance on external inputs,and mitigate environmental impacts associated with conventional agricultural practices.Despite challenges related to regulatory approval and public acceptance,the integration of synthetic biology in agriculture holds immense promise for creating more resilient and sustainable agricultural systems,contributing to global food security and environmental sustainability.Rigorous multi-field testing of these approaches will undoubtedly be required to ensure reproducibility.展开更多
Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field c...Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field coupled with chloride ions(Cl-)fixation strategy in dual single-atom catalysts(DSACs)was proposed,and the resultant catalyst delivered considerable ORR performance in a seawater electrolyte,with a high half-wave potential(E_(1/2))of 0.868 V and a good maximum power density(Pmax)of 182 mW·cm^(−2)in the assembled SZABs,much higher than those of the Pt/C catalyst(E_(1/2):0.846 V;Pmax:150 mW·cm^(−2)).The in-situ characterization and theoretical calculations revealed that the Fe sites have a higher Cl^(−)adsorption affinity than the Co sites,and preferentially adsorbs Cl^(−)in a seawater electrolyte during the ORR process,and thus constructs a low-concentration Cl^(−)local microenvironment through the common-ion exclusion effect,which prevents Cl^(−)adsorption and corrosion in the Co active centers,achieving impressive catalytic stability.In addition,the directional charge movement between Fe and Co atomic pairs establishes a local electric field,optimizing the adsorption energy of Co sites for oxygen-containing intermediates,and further improving the ORR activity.展开更多
Symbiotic nitrogen fixation in members of the Fabaceae family is highly efficient and beneficial for global agriculture,but not all species in this family form root nodules with rhizobial bacteria.Nodulation mainly oc...Symbiotic nitrogen fixation in members of the Fabaceae family is highly efficient and beneficial for global agriculture,but not all species in this family form root nodules with rhizobial bacteria.Nodulation mainly occurs in plants belonging to the Papilionoideae and Caesalpinioideae subfamilies(Tederso0 et al.,2018;van Velzen et al.,2019).Nodulation mechanisms in Fabaceae are well studied(Yang et al.,2022),and genomic comparisons of nodulating and non-nodulating host species can provide valuable insights into the evolutionary and genetic basis of this key process.展开更多
Diazotrophs make important contributions to nitrogen(N) inputs in agricultural ecosystems. However, strong evidence of the effects of conservation tillage(CT) on the coexistence and assembly of soil diazotrophic commu...Diazotrophs make important contributions to nitrogen(N) inputs in agricultural ecosystems. However, strong evidence of the effects of conservation tillage(CT) on the coexistence and assembly of soil diazotrophic community and related mechanisms is lacking. Here, a long-term experiment was conducted to study the impacts of CT on the coexistence and assembly patterns of soil diazotrophic community in Lishu County, Jilin Province, North China. Compared to traditional tillage(control, CK), CT significantly reduced both the N fixation rate in top 0–10 cm soil and the alpha diversity of diazotrophic community while increasing the density of diazotrophic and overall bacterial communities. Conservation tillage also reduced the competitive relationships within the diazotrophic community and enhanced network stability. Furthermore, diazotroph assembly was dominated by deterministic processes(relative influence =68.63%) under CK and stochastic processes(relative influence = 58.82%) under CT. Soil depth and total N(TN) were identified as crucial predictors shaping the assembly processes of diazotrophic community under different tillage practices. The relative influence of stochastic processes on diazotrophic community under CT varied more significantly with increasing soil depth. Overall, tillage practice and soil depth had significant influences on the coexistence and assembly processes of soil diazotrophic community. Moreover, long-term CT may impact the selection of N fixation agents and the specific taxa associated with N fixers. Our results indicated that in CT systems, relatively sufficient nutrient availability led to a reduction in interspecies competition, an increase in network stability, and a greater influence of stochastic processes on community assembly. These findings may help us better understand biological N fixation in sustainable agricultural systems.展开更多
In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal...In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal-organic framework,Ce-UiO-66.Vermiculite was treated with formic acid;thus,Ce-UiO-66 particles grew in-situ on vermiculite;then,Ce-UiO-66 particles were activated by ultraviolet irradiation.The vermiculite absorbed visible light with a narrow band gap,and transferred photogenerated electrons to the active sites on Ce-UiO-66.Moreover,the lamella structure of vermiculite protected Ce-UiO-66 during photocatalytic process.Therefore,with only 45.92 wt%of Ce-UiO-66,the nitrogen fixation performance of VMCeact was 2.29 times that of pure activated Ce-UiO-66 particles under 455nm light irradiation(apparent quantum efficiency of 4.49%),and retained at least 96.05%performance after 7×24 h of photocatalytic reaction.This cost-reduced,efficient and stable photocatalyst has the opportunity to facilitate environmentally friendly ammonia production.展开更多
Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also par...Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also paralleleds by the high CO_(2) emissions associated with its production.Therefore,decarbonizing NH3 synthesis is one of the most urgent contemporary challenges.Taking inspiration from Nature,solar-driven nitrogen fixation under mild conditions is one of the most promising yet challenging alternatives to classic methods.In this review,we focused our attention on the photocatalytic methods for the synthesis of ammonia;in particular,we concentrated on stable and recyclable heterogeneous Fe-based photocatalysts for producing NH3.Indeed,recoverable and widely abundant and low-cost iron catalysts may represent a very promising tool for future sustainable access to this largely desired chemical target.After an overview of the pioneering works on Fe-driven nitrogen photofixation,the recent strategies on the use of Fe are herein reported.Compared with pristine photocatalysts,adding Fe as dopant or composite and heterojunction highly enhances the photocatalytic performances,opening the way to sustainable and low-cost nitrogen production.展开更多
To compare the clinical efficacy of locking plate(LP)fixation and intramedullary nail(IMN)fixation for the treatment of post-traumatic nonunion of diaphyseal fractures of the femur and tibia.Methods:This single-center...To compare the clinical efficacy of locking plate(LP)fixation and intramedullary nail(IMN)fixation for the treatment of post-traumatic nonunion of diaphyseal fractures of the femur and tibia.Methods:This single-center retrospective comparative study included 50 adult patients with aseptic nonunion of femoral or tibial diaphyseal fractures treated at our institution between January 2015 and January 2025.Patients underwent either locking-plate(LP)fixation(n=25)or intramedullary nailing(IMN)(n=25).The primary outcome was radiographic union at 12 months postoperatively.Secondary outcomes included time to union,operative time,intraoperative blood loss,length of hospital stay,incidence of complications(superficial/deep infection,implant failure,malunion),and 12-month functional status assessed by the Lower Extremity Functional Scale(LEFS).Statistical comparisons used Welch t tests for continuous variables andχ²or Fisher exact tests for categorical variables.The protocol received institutional review board approval with waiver of informed consent.Results:Among 50 patients(LP=25;IMN=25),the 12-month union rate was 88.00%(22/25)in the LP group and 96.00%(24/25)in the IMN group(p=0.609).Time to union was shorter with IMN(6.20±1.83 vs 7.51±2.12 months;p=0.023).Operative time(110.52±25.23 vs 145.81±30.21 min;p<0.01)and intraoperative blood loss(250.41±80.64 vs 350.22±95.30 ml;p<0.01)favored IMN.Length of hospital stay was similar(6.24±1.83 vs 6.82±2.11 days;p=0.284).The incidence of superficial wound infection did not differ significantly(12.00%vs 4.00%;p=0.609).Twelve-month LEFS scores were comparable(65.44±10.21 vs 67.10±9.83;p=0.451).Conclusion:Both locking plate and intramedullary nail fixation are effective in the treatment of femoral and tibial nonunion,with high rates of union and good functional outcomes.Intramedullary nailing may be associated with a shorter time to union,reduced operative time and blood loss,and a lower risk of superficial wound infection compared to locking plate fixation.The choice of implant should be individualized based on fracture characteristics,patient factors,and surgeon preference.展开更多
The isolation of bacteria from the rhizosphere soil of different plants and locations in Diwaniyah Governorate and their diagnosis by two methods.Isolation and routine molecular diagnosis revealed ten bacterial isolat...The isolation of bacteria from the rhizosphere soil of different plants and locations in Diwaniyah Governorate and their diagnosis by two methods.Isolation and routine molecular diagnosis revealed ten bacterial isolates with the attributes of P.fluorescens out of fifteen local isolates that are represented by the following codes and sequences(P.f9,P.f8,P.f6,P.f5,P.f4,P.f2,P.f1,P.f14,P.f13,P.f11).Results also confirmed the diagnosis of bacterial isolates by biochemical and molecular tests using a specialized primer to amplify the bp698 region of the 16S ribosomal RNA gene,approved by Macrogen/Korea.The test efficiency in dissolving solid phosphate by P.fluorescens bacteria showed that the most effective is the(P.f1)isolate,giving the highest score effectiveness in mineral phosphate dissolution by the diameter of the clear zone around the colony,which was effective in phosphate dissolution up to 6.95 mm.The efficiency of the Nitrogen Fixation Test showed that the isolate(P.f5)scored the highest nitrogen-fixing efficiency amount with a value of 6.81 mg L^(-1).The quantitative amount of the hormone for each of Auxins,Cytokinins,and Gibberellins was assayed;the results with isolate(P.f1)for IAA(Auxins)gave a concentration up to 28.6μg ml^(-1),which was the most,while the production of GA3 by isolate(P.f1)gave the maximum value of 36.7μg ml^(-1),and for synthesis of the hormone of Cytokinins represented by isolate(P.f2),the highest value in the production of Cytokinins hormone was recorded at 26.3μg ml^(-1).展开更多
Management of post-traumatic long-bone defects remains relevant and cha-llenging despite the rapid development of approaches to their treatment.Do-minant positions are occupied by the Ilizarov method,bone autogenous g...Management of post-traumatic long-bone defects remains relevant and cha-llenging despite the rapid development of approaches to their treatment.Do-minant positions are occupied by the Ilizarov method,bone autogenous grafting and the Masquelet induced membrane technique(IMT).The IMT is aimed at reducing extensive defect treatment duration and for this reason has gained great popularity.However,the assessment of its effectiveness is difficult due to a limited number of clinical series.The varying clinical manifestations of bone defect severity do not allow a comprehensive evaluation of IMT effectiveness.One of them is infection in the defect area.The purpose of our literature review is an analysis of studies on IMT application in infected vs non-infected long-bone defects of the lower extremities published over the last 10 years.It focuses on the investigation of similarities and fundamental differences in the need for antibiotics,timing of spacer fixation,methods of collecting donor bone and fixators used for consolidation.The studies show that the IMT has been globally used in aseptic and osteomyelitic defects due to its clinical effectiveness.Authors’variations and improvements in its practical implementation indicate the ongoing development and the interest of researchers in this technique.展开更多
Background : Scleral fixation of intraocular lenses is a surgical technique that involves anchoring an artificial lens to the sclera. Traditional approaches, such as capsular bag placement, may not be feasible in cert...Background : Scleral fixation of intraocular lenses is a surgical technique that involves anchoring an artificial lens to the sclera. Traditional approaches, such as capsular bag placement, may not be feasible in certain situations, making scleral fixation a valuable alternative. The scleral reactions to different types of suture materials are not fully understood. Therefore, the present study describes the microscopic structure of normal scleral tissue and its changes with suture materials. Methods : We compared six groups of rabbit eyes focusing on the sclera: group with polytetrafluoroethylene( PTFE) chain, PTFE fiber, polypropylene( PPE) fiber and control groups. multilevel sampling and stereological methods were used for histological quantification of the leukocyte infiltration fractions and type Ⅰ and type Ⅲ collagen. Results : Quantitative histological evaluation revealed the following:(1) For all materials used, inflammation was present in the surrounding scleral tissue compared with healthy controls. However, leukocyte infiltration in the sclera was not statistically different between the materials.(2) As part of the evaluation of collagen, the greatest changes occurred in the PTFE fiber group at 2 weeks postoperatively. In the PTFE chain group, more significant changes were visible at 4 weeks.(3) The changes in the PPE fiber group compared to healthy scleral tissue were the least significant. Conclusions : From a histological point of view, it is evident that there are differences in the quantitative parameters between the untouched sclera and the sclera with suture material. Furthermore, distinctions were observed among various materials and across different time intervals.展开更多
The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios re...The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios require a more specialized approach,and some groups of patients may benefit from customized Ilizarov constructs.Engineering science has designed various external fixators for orthopedic purposes,and some of those have become the gold standard for specific clinical tasks.We aimed to determine the current state and novel modifications of specialized external fixators for specific clinical situations which are based on the principles of the Ilizarov method.They are half-pin-based fixators for temporal fracture fixation,ring or hybrid devices for gradual deformity correction,and compression-distraction devices tailored for definite limb segments.Gradual correction of deformities can be achieved with external hexapods incorporating universal reduction units.Alternatively,external fixators with special connection mechanisms are able to provide independent movement of the rings in six degrees of freedom.Deformity correction can be performed with combined or sequential use of external and internal fixators.Special devices were developed for moving the split fragment for revascularization of the tibia.The units of external frames on the foot were modified to consider its complex anatomy and the clinical needs ranging from correction of multi-plane deformities,joint arthrodesis to distraction arthroplasty.Mini-fixators are compact external fixators for small bones of the hand and foot.The varieties of external fixators based on the Ilizarov principles have been designed to fulfill an ultimate goal of improving treatment outcomes.展开更多
Legumes,such as peas,beans,and alfalfa,have evolved a remarkable ability to establish root nodule symbioses with nitrogen-fixing soil bacteria to fulfill their nitrogen needs.This partnership is characterized by a hig...Legumes,such as peas,beans,and alfalfa,have evolved a remarkable ability to establish root nodule symbioses with nitrogen-fixing soil bacteria to fulfill their nitrogen needs.This partnership is characterized by a high degree of specificity,occurring both within and between host and bacterial species.Consequently,nodulation capacity and nitrogen-fixing efficiency vary significantly among different plant–bacteria pairs.The genetic and molecular mechanisms regulating symbiotic specificity are diverse,involving a wide array of host and bacterial genes and signals with various modes of action.Understanding the genetic basis of symbiotic specificity could enable the development of strategies to enhance nodulation capacity and nitrogen fixation efficiency.This knowledge will also help overcome the host range barrier,which is a critical step toward extending root nodule symbiosis to non-leguminous plants.In this review,we provide an update on our current understanding of the genetics and evolution of recognition specificity in root nodule symbioses,providing more comprehensive insights into the molecular signaling in plant–bacterial interactions.展开更多
High atmospheric vapor pressure deficit(VPD)reduces the calcium(Ca)distribution in tomato(Solanum lycopersicum L.)fruits,severely reducing fruit mass.Reducing the VPD or increasing Ca fertilizer is an important measur...High atmospheric vapor pressure deficit(VPD)reduces the calcium(Ca)distribution in tomato(Solanum lycopersicum L.)fruits,severely reducing fruit mass.Reducing the VPD or increasing Ca fertilizer is an important measure to improve Ca distribution in fruits.However,the mechanism through which VPD and Ca regulate fruit Ca distribution remains unclear.This study investigated the effects of high and low VPD and Ca levels on Ca distribution and fruit mass based on carbon fixation,water transport dynamics,and pectin and Ca content and identified key differential genes and metabolites through transcriptome and metabolome analyses.The results showed that both reducing VPD under low Ca and increasing Ca under high VPD increased water and Ca transport to fruits.The increased Ca combined with pectin to form Ca pectinate,which effectively stabilized the cell wall and enhanced the fruit mass.Reduced VPD under low Ca increased the distribution of Ca to fruits but decreased the distribution of Ca to leaves.Lower Ca distribution in leaves increased their absorption of other nutrients,such as potassium,magnesium,copper,and zinc,which increased the stomatal size and density,thereby improving plant carbon absorption and assimilation efficiency.However,transcriptomic and metabolomic data indicated that carbohydrates,as important regulatory factors under drought stress,increased significantly under high VPD,thereby reducing the fruit water potential while improving fruit water and Ca absorption.Therefore,the carbon assimilation efficiency,water transport capacity,and differential genes and metabolites regulated Ca distribution.This work provides a theoretical basis for environmental and fertilizer management in greenhouse tomato production.展开更多
Symbiotic and asymbiotic nitrogen fixation(SNF and ANF),two forms of biological nitrogen(N)fixation,are the main pathways for external N inputs into natural terrestrial ecosystems.However,the regulatory mechanisms of ...Symbiotic and asymbiotic nitrogen fixation(SNF and ANF),two forms of biological nitrogen(N)fixation,are the main pathways for external N inputs into natural terrestrial ecosystems.However,the regulatory mechanisms of SNF and ANF,particularly in response to changing environmental conditions,remain poorly understood.Here,we investigated changes in SNF and ANF rates along two altitudinal gradients in two subtropical forests on soils with granite and slate parent materials.Our results revealed distinct patterns for SNF and ANF rates.SNF rates consistently declined with increasing altitude,whereas ANF rates initially increased at lower altitudes but declined at higher altitudes.These contrasting trends were attributed to divergent regulatory mechanisms of SNF and ANF rates.Specifically,the decrease in SNF rates was primarily driven by increased soil N availability and decreased air temperature.However,the drivers of ANF rates shifted from soil properties(e.g.,phosphorus,iron,and moisture)at lower altitudes to climatic factors(e.g.,air temperature)at higher altitudes.We also observed opposite trends of SNF and ANF between forests on granite and slate,demonstrating that lithology is an important driver of both SNF and ANF.Collectively,our findings highlight the divergent mechanisms regulating SNF and ANF in subtropical forests,which contribute to improving the mechanistic representation of biological N fixation in Earth system models.展开更多
The advancement in catalysis techniques for sustainable environmental applications,particularly an alternative to the current Haber-Bosch process for NH_(3),has recently gained widespread attention.Although photocatal...The advancement in catalysis techniques for sustainable environmental applications,particularly an alternative to the current Haber-Bosch process for NH_(3),has recently gained widespread attention.Although photocatalytic conversion of N_(2) to NH_(3) using solar energy is an eco-friendly method,it has the limitation of low quantum yield.Recently,2D Bi-based photocatalysts which exhibit higher visible light absorption than TiO_(2) and higher stability than MXene have been an active research topic,and their performance can be enhanced through improved visible light absorption properties by incorporating plasmonic gold nanoparticles while nitrogen adsorption could be enhanced through oxygen vacancy(OV)processes.In the present study,we explore the application of 2D nanosized Bi_(2)O_(3–x) and gold nanoparticles for visible light photo generation of NH_(3).HRTEM and XPS reveal that the formation of AuNP and nano-sized Bi_(2)O_(3–x) in AuNP/Bi_(2)O_(3–x) heterozygote structure promotes the charge carrier mobility and charge transport at the interface,resulting in a 2.6-fold increase in the photocatalytic activity compared to micro-sized Bi_(2)O_(3–x) with AuNP.The improved photocatalytic performance can be ascribed to significant enhancement of visible light absorption by plasmonic nanoparticles,fast charge transport and mobility(due to sheet morphology)and the N_(2) activation by OV in AuNP/Bi_(2)O_(3–x) heterozygote.Through a systematic experimental investigation involving catalysts,concentration,pH,and scavengers,the highest photocatalytic performance was achieved with the heterozygote structures of AuNP/n-Bi_(2)O_(3–x) under optimized conditions,yielding 432.5μmol gcat^(-1) h^(-1) of NH_(3).展开更多
Electrochemical nitrogen reduction reaction(ENRR)is emerging as a favorable option to the power-intensive Haber-Bosch process for ammonia synthesis.However,obstacles such as poor selectivity,low production rates,and c...Electrochemical nitrogen reduction reaction(ENRR)is emerging as a favorable option to the power-intensive Haber-Bosch process for ammonia synthesis.However,obstacles such as poor selectivity,low production rates,and competition against the hydrogen evolution reaction hinder its practical implementation.To address these,the design of highly active catalysts is critical.Single-atom catalysts(SACs)have shown great potential because of their maximized atom utilization,but their limited stability and low metal loading restrict their performances.On the other hand,dual-atom catalysts(DACs)are atomic catalysts with two metal atoms nearby and offer enhanced electrocatalytic performances by aligning with the N≡N bond to enhance N2 reduction efficiency,potentially overcoming the limitations of SAC.This review discusses recent advances in SACs and more importantly DACs for ENRR,highlighting their advantages,limitations,and the need for advanced characterization techniques to better understand catalyst behavior.The review concludes by underscoring the importance of research to optimize these catalysts for efficient and sustainable nitrogen fixation.展开更多
Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a...Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a 1.8-fold excess of KOH at 400℃ for 3 h enabled the leaching of over 99%of Mo from the molybdenum calcine using water.A precipitation method involving potassium–magnesium(K-Mg)salts was proposed for impurity removal.Under the conditions of pH 11,30℃,excess coefficient of 1.7 for Mg salts,and a duration of 1 h,98.37%of phosphorus(P)was removed from the K_(2)MoO_(4) solution.With post-purification,over 99%of Mo crystallized upon adjustment of pH to 1.Subsequently,S and K were recovered as K_(2)SO_(4) fertilizer from the crystalline mother liquor.An environmentally sustainable approach was proposed to conduct molybdenite production and ensure the efficient recovery of both Mo and S.展开更多
文摘Background: Complications after endoscopic retrieval of kidney and ureter stones are obviously related to the size of the stones as well as the experience of the surgeon and other factors. During the procedure it is sometimes difficult for surgeons to estimate stone size and therefore give prognostic advises. The visual perception of the stone size depends on the shape, colour, distance to the renoscope and dilatation of the ureter. This is the so-called binding problem, because shape, color and direction of motion are processed separately by different population of optical neurons. In order to establish a better prognostic rational especially for less experienced surgeons, we established an intra operative semi-quantitative measurement of the stone size supported by a stone basket. Materials and Methods: We modified the tipped, nitinol stone baskets from the company Urotech with diameters of 2.5, 3.0 and 4 FR. The handle of this basket has a spring mechanism, which automatically closes the basket and provides a predefined fixation force of the stones within the basket. On the handle we established a non-linear scale in mm by grabbing standardized balls or standardized screws. Result: The scales are nonlinear because of the nonlinear relation between the diameter of the stone and the distance of the slider. Also the scales differ in between the basket size, because of the different strain conditions due to the different wire sizes and materials or the spring and basket. Conclusion: This scale could be an important orientation for a surgeon during endourological procedures to estimate stone sizes. After further clinical experience a semi-quantitative visualization like green, yellow and red colors could help to predict potential complications due to large stone sizes. Finally it could bevery interesting for other disciplines like gastroenterology.
文摘Laparoscopic totally extraperitoneal (TEP) hernia repair is a well-accepted technique for inguinal hernia repair. Different types of mesh and fixation methods have been described. Recently, a novel, self-fixating mesh has been introduced and used successfully in open inguinal hernia repairs. We report the first initial experience using this mesh for TEP repairs.
基金supported by the National Key R&D Program of China(No.2023YFC3709500).
文摘Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Category B,XDB1090000).
文摘Plant synthetic biology has emerged as a transformative field in agriculture,offering innovative solutions to enhance food security,provide resilience to climate change,and transition to sustainable farming practices.By integrating advanced genetic tools,computational modeling,and systems biology,researchers can precisely modify plant genomes to enhance traits such as yield,stress tolerance,and nutrient use efficiency.The ability to design plants with specific characteristics tailored to diverse environmental conditions and agricultural needs holds great potential to address global food security challenges.Here,we highlight recent advancements and applications of plant synthetic biology in agriculture,focusing on key areas such as photosynthetic efficiency,nitrogen fixation,drought tolerance,pathogen resistance,nutrient use efficiency,biofortification,climate resilience,microbiology engineering,synthetic plant genomes,and the integration of artificial intelligence with synthetic biology.These innovations aim to maximize resource use efficiency,reduce reliance on external inputs,and mitigate environmental impacts associated with conventional agricultural practices.Despite challenges related to regulatory approval and public acceptance,the integration of synthetic biology in agriculture holds immense promise for creating more resilient and sustainable agricultural systems,contributing to global food security and environmental sustainability.Rigorous multi-field testing of these approaches will undoubtedly be required to ensure reproducibility.
基金supported by the National Natural Science Foundation of China(52164028,52274297)the Start-up Research Foundation of Hainan University(KYQD(ZR)20008,KYQD(ZR)21125,KYQD(ZR)23169))+1 种基金Collaborative Innovation Center of Marine Science and Technology of Hainan University(XTCX2022HYC14)Innovative Research Project for Postgraduate Students in Hainan Province(Qhyb2024-95).
文摘Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field coupled with chloride ions(Cl-)fixation strategy in dual single-atom catalysts(DSACs)was proposed,and the resultant catalyst delivered considerable ORR performance in a seawater electrolyte,with a high half-wave potential(E_(1/2))of 0.868 V and a good maximum power density(Pmax)of 182 mW·cm^(−2)in the assembled SZABs,much higher than those of the Pt/C catalyst(E_(1/2):0.846 V;Pmax:150 mW·cm^(−2)).The in-situ characterization and theoretical calculations revealed that the Fe sites have a higher Cl^(−)adsorption affinity than the Co sites,and preferentially adsorbs Cl^(−)in a seawater electrolyte during the ORR process,and thus constructs a low-concentration Cl^(−)local microenvironment through the common-ion exclusion effect,which prevents Cl^(−)adsorption and corrosion in the Co active centers,achieving impressive catalytic stability.In addition,the directional charge movement between Fe and Co atomic pairs establishes a local electric field,optimizing the adsorption energy of Co sites for oxygen-containing intermediates,and further improving the ORR activity.
基金supported by the National Natural Science Foundation of China(No.32160142)Guangxi Natural Science Foundation(No.2023GXNSFDA026034)+3 种基金State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources(SKLCUSAb202302)to H.W.,the National Natural Science Foundation of China(No.32460062)to Y.L.,and 1+9 Leading the Charge with Open Competition'project of Sichuan Academy of Agricultural Sciences(1+9KJGG010)Fruit tree breeding project in Sichuan Province(2021YFYZ0023)to H.X.
文摘Symbiotic nitrogen fixation in members of the Fabaceae family is highly efficient and beneficial for global agriculture,but not all species in this family form root nodules with rhizobial bacteria.Nodulation mainly occurs in plants belonging to the Papilionoideae and Caesalpinioideae subfamilies(Tederso0 et al.,2018;van Velzen et al.,2019).Nodulation mechanisms in Fabaceae are well studied(Yang et al.,2022),and genomic comparisons of nodulating and non-nodulating host species can provide valuable insights into the evolutionary and genetic basis of this key process.
基金funded by the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDA28020202)the National Natural Science Foundation of China (No. 42277336)+3 种基金the Natural Science Foundation of Jiangsu Province, China (No. BK20221561)the China Agriculture Research System (Nos. CARS-03 and CARS52)the National Key Research and Development Program of China (No. 2022YFD1500401)the Jiangsu Agricultural Science and Technology Innovation Fund of China (No. CX(24)1003)。
文摘Diazotrophs make important contributions to nitrogen(N) inputs in agricultural ecosystems. However, strong evidence of the effects of conservation tillage(CT) on the coexistence and assembly of soil diazotrophic community and related mechanisms is lacking. Here, a long-term experiment was conducted to study the impacts of CT on the coexistence and assembly patterns of soil diazotrophic community in Lishu County, Jilin Province, North China. Compared to traditional tillage(control, CK), CT significantly reduced both the N fixation rate in top 0–10 cm soil and the alpha diversity of diazotrophic community while increasing the density of diazotrophic and overall bacterial communities. Conservation tillage also reduced the competitive relationships within the diazotrophic community and enhanced network stability. Furthermore, diazotroph assembly was dominated by deterministic processes(relative influence =68.63%) under CK and stochastic processes(relative influence = 58.82%) under CT. Soil depth and total N(TN) were identified as crucial predictors shaping the assembly processes of diazotrophic community under different tillage practices. The relative influence of stochastic processes on diazotrophic community under CT varied more significantly with increasing soil depth. Overall, tillage practice and soil depth had significant influences on the coexistence and assembly processes of soil diazotrophic community. Moreover, long-term CT may impact the selection of N fixation agents and the specific taxa associated with N fixers. Our results indicated that in CT systems, relatively sufficient nutrient availability led to a reduction in interspecies competition, an increase in network stability, and a greater influence of stochastic processes on community assembly. These findings may help us better understand biological N fixation in sustainable agricultural systems.
基金supported by the National Natural Science Foundation of China(Nos.21978251,22102141 and U1904215)Natural Science Foundation of Jiangsu Province(No.BK20200044).
文摘In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal-organic framework,Ce-UiO-66.Vermiculite was treated with formic acid;thus,Ce-UiO-66 particles grew in-situ on vermiculite;then,Ce-UiO-66 particles were activated by ultraviolet irradiation.The vermiculite absorbed visible light with a narrow band gap,and transferred photogenerated electrons to the active sites on Ce-UiO-66.Moreover,the lamella structure of vermiculite protected Ce-UiO-66 during photocatalytic process.Therefore,with only 45.92 wt%of Ce-UiO-66,the nitrogen fixation performance of VMCeact was 2.29 times that of pure activated Ce-UiO-66 particles under 455nm light irradiation(apparent quantum efficiency of 4.49%),and retained at least 96.05%performance after 7×24 h of photocatalytic reaction.This cost-reduced,efficient and stable photocatalyst has the opportunity to facilitate environmentally friendly ammonia production.
基金funded by the European Union-NextGenerationEU under the Italian Ministry of University and Research(MUR)National Innovation Ecosystem grant ECS00000041-VITALITYThe University of Perugia is acknowledged for financial support to the university project“Fondo Ricerca di Ateneo,edizione 2021”and“Fondo Ricerca di Ateneo,edizione 2022”CSGI(Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase)for the support.
文摘Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also paralleleds by the high CO_(2) emissions associated with its production.Therefore,decarbonizing NH3 synthesis is one of the most urgent contemporary challenges.Taking inspiration from Nature,solar-driven nitrogen fixation under mild conditions is one of the most promising yet challenging alternatives to classic methods.In this review,we focused our attention on the photocatalytic methods for the synthesis of ammonia;in particular,we concentrated on stable and recyclable heterogeneous Fe-based photocatalysts for producing NH3.Indeed,recoverable and widely abundant and low-cost iron catalysts may represent a very promising tool for future sustainable access to this largely desired chemical target.After an overview of the pioneering works on Fe-driven nitrogen photofixation,the recent strategies on the use of Fe are herein reported.Compared with pristine photocatalysts,adding Fe as dopant or composite and heterojunction highly enhances the photocatalytic performances,opening the way to sustainable and low-cost nitrogen production.
文摘To compare the clinical efficacy of locking plate(LP)fixation and intramedullary nail(IMN)fixation for the treatment of post-traumatic nonunion of diaphyseal fractures of the femur and tibia.Methods:This single-center retrospective comparative study included 50 adult patients with aseptic nonunion of femoral or tibial diaphyseal fractures treated at our institution between January 2015 and January 2025.Patients underwent either locking-plate(LP)fixation(n=25)or intramedullary nailing(IMN)(n=25).The primary outcome was radiographic union at 12 months postoperatively.Secondary outcomes included time to union,operative time,intraoperative blood loss,length of hospital stay,incidence of complications(superficial/deep infection,implant failure,malunion),and 12-month functional status assessed by the Lower Extremity Functional Scale(LEFS).Statistical comparisons used Welch t tests for continuous variables andχ²or Fisher exact tests for categorical variables.The protocol received institutional review board approval with waiver of informed consent.Results:Among 50 patients(LP=25;IMN=25),the 12-month union rate was 88.00%(22/25)in the LP group and 96.00%(24/25)in the IMN group(p=0.609).Time to union was shorter with IMN(6.20±1.83 vs 7.51±2.12 months;p=0.023).Operative time(110.52±25.23 vs 145.81±30.21 min;p<0.01)and intraoperative blood loss(250.41±80.64 vs 350.22±95.30 ml;p<0.01)favored IMN.Length of hospital stay was similar(6.24±1.83 vs 6.82±2.11 days;p=0.284).The incidence of superficial wound infection did not differ significantly(12.00%vs 4.00%;p=0.609).Twelve-month LEFS scores were comparable(65.44±10.21 vs 67.10±9.83;p=0.451).Conclusion:Both locking plate and intramedullary nail fixation are effective in the treatment of femoral and tibial nonunion,with high rates of union and good functional outcomes.Intramedullary nailing may be associated with a shorter time to union,reduced operative time and blood loss,and a lower risk of superficial wound infection compared to locking plate fixation.The choice of implant should be individualized based on fracture characteristics,patient factors,and surgeon preference.
文摘The isolation of bacteria from the rhizosphere soil of different plants and locations in Diwaniyah Governorate and their diagnosis by two methods.Isolation and routine molecular diagnosis revealed ten bacterial isolates with the attributes of P.fluorescens out of fifteen local isolates that are represented by the following codes and sequences(P.f9,P.f8,P.f6,P.f5,P.f4,P.f2,P.f1,P.f14,P.f13,P.f11).Results also confirmed the diagnosis of bacterial isolates by biochemical and molecular tests using a specialized primer to amplify the bp698 region of the 16S ribosomal RNA gene,approved by Macrogen/Korea.The test efficiency in dissolving solid phosphate by P.fluorescens bacteria showed that the most effective is the(P.f1)isolate,giving the highest score effectiveness in mineral phosphate dissolution by the diameter of the clear zone around the colony,which was effective in phosphate dissolution up to 6.95 mm.The efficiency of the Nitrogen Fixation Test showed that the isolate(P.f5)scored the highest nitrogen-fixing efficiency amount with a value of 6.81 mg L^(-1).The quantitative amount of the hormone for each of Auxins,Cytokinins,and Gibberellins was assayed;the results with isolate(P.f1)for IAA(Auxins)gave a concentration up to 28.6μg ml^(-1),which was the most,while the production of GA3 by isolate(P.f1)gave the maximum value of 36.7μg ml^(-1),and for synthesis of the hormone of Cytokinins represented by isolate(P.f2),the highest value in the production of Cytokinins hormone was recorded at 26.3μg ml^(-1).
文摘Management of post-traumatic long-bone defects remains relevant and cha-llenging despite the rapid development of approaches to their treatment.Do-minant positions are occupied by the Ilizarov method,bone autogenous grafting and the Masquelet induced membrane technique(IMT).The IMT is aimed at reducing extensive defect treatment duration and for this reason has gained great popularity.However,the assessment of its effectiveness is difficult due to a limited number of clinical series.The varying clinical manifestations of bone defect severity do not allow a comprehensive evaluation of IMT effectiveness.One of them is infection in the defect area.The purpose of our literature review is an analysis of studies on IMT application in infected vs non-infected long-bone defects of the lower extremities published over the last 10 years.It focuses on the investigation of similarities and fundamental differences in the need for antibiotics,timing of spacer fixation,methods of collecting donor bone and fixators used for consolidation.The studies show that the IMT has been globally used in aseptic and osteomyelitic defects due to its clinical effectiveness.Authors’variations and improvements in its practical implementation indicate the ongoing development and the interest of researchers in this technique.
基金supported by the Charles University Cooperatio Program,Research Areas MED/DIAG,and Surgical Disciplinessupport from the Ministry of Education,Youth,and Sports of the Czech Republic under Project FIND No.CZ.02.1.01/0.0/0.0/16_019/0000787.L.V.was also supported by Charles University SVV-2025260773.
文摘Background : Scleral fixation of intraocular lenses is a surgical technique that involves anchoring an artificial lens to the sclera. Traditional approaches, such as capsular bag placement, may not be feasible in certain situations, making scleral fixation a valuable alternative. The scleral reactions to different types of suture materials are not fully understood. Therefore, the present study describes the microscopic structure of normal scleral tissue and its changes with suture materials. Methods : We compared six groups of rabbit eyes focusing on the sclera: group with polytetrafluoroethylene( PTFE) chain, PTFE fiber, polypropylene( PPE) fiber and control groups. multilevel sampling and stereological methods were used for histological quantification of the leukocyte infiltration fractions and type Ⅰ and type Ⅲ collagen. Results : Quantitative histological evaluation revealed the following:(1) For all materials used, inflammation was present in the surrounding scleral tissue compared with healthy controls. However, leukocyte infiltration in the sclera was not statistically different between the materials.(2) As part of the evaluation of collagen, the greatest changes occurred in the PTFE fiber group at 2 weeks postoperatively. In the PTFE chain group, more significant changes were visible at 4 weeks.(3) The changes in the PPE fiber group compared to healthy scleral tissue were the least significant. Conclusions : From a histological point of view, it is evident that there are differences in the quantitative parameters between the untouched sclera and the sclera with suture material. Furthermore, distinctions were observed among various materials and across different time intervals.
文摘The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios require a more specialized approach,and some groups of patients may benefit from customized Ilizarov constructs.Engineering science has designed various external fixators for orthopedic purposes,and some of those have become the gold standard for specific clinical tasks.We aimed to determine the current state and novel modifications of specialized external fixators for specific clinical situations which are based on the principles of the Ilizarov method.They are half-pin-based fixators for temporal fracture fixation,ring or hybrid devices for gradual deformity correction,and compression-distraction devices tailored for definite limb segments.Gradual correction of deformities can be achieved with external hexapods incorporating universal reduction units.Alternatively,external fixators with special connection mechanisms are able to provide independent movement of the rings in six degrees of freedom.Deformity correction can be performed with combined or sequential use of external and internal fixators.Special devices were developed for moving the split fragment for revascularization of the tibia.The units of external frames on the foot were modified to consider its complex anatomy and the clinical needs ranging from correction of multi-plane deformities,joint arthrodesis to distraction arthroplasty.Mini-fixators are compact external fixators for small bones of the hand and foot.The varieties of external fixators based on the Ilizarov principles have been designed to fulfill an ultimate goal of improving treatment outcomes.
基金Research in the Hongyan Zhu group is supported by the US National Science Foundation Grant IOS-1758037.
文摘Legumes,such as peas,beans,and alfalfa,have evolved a remarkable ability to establish root nodule symbioses with nitrogen-fixing soil bacteria to fulfill their nitrogen needs.This partnership is characterized by a high degree of specificity,occurring both within and between host and bacterial species.Consequently,nodulation capacity and nitrogen-fixing efficiency vary significantly among different plant–bacteria pairs.The genetic and molecular mechanisms regulating symbiotic specificity are diverse,involving a wide array of host and bacterial genes and signals with various modes of action.Understanding the genetic basis of symbiotic specificity could enable the development of strategies to enhance nodulation capacity and nitrogen fixation efficiency.This knowledge will also help overcome the host range barrier,which is a critical step toward extending root nodule symbiosis to non-leguminous plants.In this review,we provide an update on our current understanding of the genetics and evolution of recognition specificity in root nodule symbioses,providing more comprehensive insights into the molecular signaling in plant–bacterial interactions.
基金supported by grants from the Construction of Shaanxi Vegetable Industry Technology System in 2022[Grant No.NYKJ-2022-(XN)-03]the Construction of the Scientists+Engineers Team in Qin Chuangyuan,Shaanxi Province(Grant No.2023KXJ-024)。
文摘High atmospheric vapor pressure deficit(VPD)reduces the calcium(Ca)distribution in tomato(Solanum lycopersicum L.)fruits,severely reducing fruit mass.Reducing the VPD or increasing Ca fertilizer is an important measure to improve Ca distribution in fruits.However,the mechanism through which VPD and Ca regulate fruit Ca distribution remains unclear.This study investigated the effects of high and low VPD and Ca levels on Ca distribution and fruit mass based on carbon fixation,water transport dynamics,and pectin and Ca content and identified key differential genes and metabolites through transcriptome and metabolome analyses.The results showed that both reducing VPD under low Ca and increasing Ca under high VPD increased water and Ca transport to fruits.The increased Ca combined with pectin to form Ca pectinate,which effectively stabilized the cell wall and enhanced the fruit mass.Reduced VPD under low Ca increased the distribution of Ca to fruits but decreased the distribution of Ca to leaves.Lower Ca distribution in leaves increased their absorption of other nutrients,such as potassium,magnesium,copper,and zinc,which increased the stomatal size and density,thereby improving plant carbon absorption and assimilation efficiency.However,transcriptomic and metabolomic data indicated that carbohydrates,as important regulatory factors under drought stress,increased significantly under high VPD,thereby reducing the fruit water potential while improving fruit water and Ca absorption.Therefore,the carbon assimilation efficiency,water transport capacity,and differential genes and metabolites regulated Ca distribution.This work provides a theoretical basis for environmental and fertilizer management in greenhouse tomato production.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(No.2025A1515011004)the Shenzhen Science and Technology Program(No.JCYJ20220530150015035)+1 种基金the National Natural Science Foundation of China(No.42367035)the Chinese Scholarship Council(No.202306380142).
文摘Symbiotic and asymbiotic nitrogen fixation(SNF and ANF),two forms of biological nitrogen(N)fixation,are the main pathways for external N inputs into natural terrestrial ecosystems.However,the regulatory mechanisms of SNF and ANF,particularly in response to changing environmental conditions,remain poorly understood.Here,we investigated changes in SNF and ANF rates along two altitudinal gradients in two subtropical forests on soils with granite and slate parent materials.Our results revealed distinct patterns for SNF and ANF rates.SNF rates consistently declined with increasing altitude,whereas ANF rates initially increased at lower altitudes but declined at higher altitudes.These contrasting trends were attributed to divergent regulatory mechanisms of SNF and ANF rates.Specifically,the decrease in SNF rates was primarily driven by increased soil N availability and decreased air temperature.However,the drivers of ANF rates shifted from soil properties(e.g.,phosphorus,iron,and moisture)at lower altitudes to climatic factors(e.g.,air temperature)at higher altitudes.We also observed opposite trends of SNF and ANF between forests on granite and slate,demonstrating that lithology is an important driver of both SNF and ANF.Collectively,our findings highlight the divergent mechanisms regulating SNF and ANF in subtropical forests,which contribute to improving the mechanistic representation of biological N fixation in Earth system models.
基金Financial support for this work by the National Research Foundation of Korea(2022R1F1A1074682,2022R1A4A1031687)Korea University,and the KU-KIST Research Fund.
文摘The advancement in catalysis techniques for sustainable environmental applications,particularly an alternative to the current Haber-Bosch process for NH_(3),has recently gained widespread attention.Although photocatalytic conversion of N_(2) to NH_(3) using solar energy is an eco-friendly method,it has the limitation of low quantum yield.Recently,2D Bi-based photocatalysts which exhibit higher visible light absorption than TiO_(2) and higher stability than MXene have been an active research topic,and their performance can be enhanced through improved visible light absorption properties by incorporating plasmonic gold nanoparticles while nitrogen adsorption could be enhanced through oxygen vacancy(OV)processes.In the present study,we explore the application of 2D nanosized Bi_(2)O_(3–x) and gold nanoparticles for visible light photo generation of NH_(3).HRTEM and XPS reveal that the formation of AuNP and nano-sized Bi_(2)O_(3–x) in AuNP/Bi_(2)O_(3–x) heterozygote structure promotes the charge carrier mobility and charge transport at the interface,resulting in a 2.6-fold increase in the photocatalytic activity compared to micro-sized Bi_(2)O_(3–x) with AuNP.The improved photocatalytic performance can be ascribed to significant enhancement of visible light absorption by plasmonic nanoparticles,fast charge transport and mobility(due to sheet morphology)and the N_(2) activation by OV in AuNP/Bi_(2)O_(3–x) heterozygote.Through a systematic experimental investigation involving catalysts,concentration,pH,and scavengers,the highest photocatalytic performance was achieved with the heterozygote structures of AuNP/n-Bi_(2)O_(3–x) under optimized conditions,yielding 432.5μmol gcat^(-1) h^(-1) of NH_(3).
基金supported by the National Research Foundation of Korea(2022R1C1C2005786,RS-2023-00256106,RS-2023-00207831,RS-2024-00346153).
文摘Electrochemical nitrogen reduction reaction(ENRR)is emerging as a favorable option to the power-intensive Haber-Bosch process for ammonia synthesis.However,obstacles such as poor selectivity,low production rates,and competition against the hydrogen evolution reaction hinder its practical implementation.To address these,the design of highly active catalysts is critical.Single-atom catalysts(SACs)have shown great potential because of their maximized atom utilization,but their limited stability and low metal loading restrict their performances.On the other hand,dual-atom catalysts(DACs)are atomic catalysts with two metal atoms nearby and offer enhanced electrocatalytic performances by aligning with the N≡N bond to enhance N2 reduction efficiency,potentially overcoming the limitations of SAC.This review discusses recent advances in SACs and more importantly DACs for ENRR,highlighting their advantages,limitations,and the need for advanced characterization techniques to better understand catalyst behavior.The review concludes by underscoring the importance of research to optimize these catalysts for efficient and sustainable nitrogen fixation.
基金financially supported by the National Natural Science Foundation of China(No.52174340)the National Key Research and Development Project of China(No.2022YFC2904505)the Hunan FURONG Scholars Project and the Basic Science Centre of the National Natural Science Foundation of China(No.72088101)。
文摘Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a 1.8-fold excess of KOH at 400℃ for 3 h enabled the leaching of over 99%of Mo from the molybdenum calcine using water.A precipitation method involving potassium–magnesium(K-Mg)salts was proposed for impurity removal.Under the conditions of pH 11,30℃,excess coefficient of 1.7 for Mg salts,and a duration of 1 h,98.37%of phosphorus(P)was removed from the K_(2)MoO_(4) solution.With post-purification,over 99%of Mo crystallized upon adjustment of pH to 1.Subsequently,S and K were recovered as K_(2)SO_(4) fertilizer from the crystalline mother liquor.An environmentally sustainable approach was proposed to conduct molybdenite production and ensure the efficient recovery of both Mo and S.
