Interfacial solar evaporation holds immense potential for brine desalination with low carbon footprints and high energy utilization.Hydrogels,as a tunable material platform from the molecular level to the macroscopic ...Interfacial solar evaporation holds immense potential for brine desalination with low carbon footprints and high energy utilization.Hydrogels,as a tunable material platform from the molecular level to the macroscopic scale,have been considered the most promising candidate for solar evaporation.However,the simultaneous achievement of high evaporation efficiency and satisfactory tolerance to salt ions in brine remains a challenging scientific bottleneck,restricting the widespread application.Herein,we report ionization engineering,which endows polymer chains of hydrogels with electronegativity for impeding salt ions and activating water molecules,fundamentally overcoming the hydrogel salt-impeded challenge and dramatically expediting water evaporating in brine.The sodium dodecyl benzene sulfonate-modified carbon black is chosen as the solar absorbers.The hydrogel reaches a ground-breaking evaporation rate of 2.9 kg m−2 h−1 in 20 wt%brine with 95.6%efficiency under one sun irradiation,surpassing most of the reported literature.More notably,such a hydrogel-based evaporator enables extracting clean water from oversaturated salt solutions and maintains durability under different high-strength deformation or a 15-day continuous operation.Meantime,on the basis of the cation selectivity induced by the electronegativity,we first propose an all-day system that evaporates during the day and generates salinity-gradient electricity using waste-evaporated brine at night,anticipating pioneer a new opportunity for all-day resource-generating systems in fields of freshwater and electricity.展开更多
Background Clearance of coronary arterial thrombosis is necessary in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing urgent percutaneous coronary intervention (PCI). There is currentl...Background Clearance of coronary arterial thrombosis is necessary in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing urgent percutaneous coronary intervention (PCI). There is currently no highly-recommended method of thrombus removal during interventional procedures. We describe a new method for opening culprit vessels to treat STEMI: intracoronary arterial retrograde thrombolysis (ICART) with PCI. Methods & Results Eight patients underwent ICART. The guidewire was advanced to the distal coronary artery through the occlusion lesion. Then, we inserted a microcatheter into the distal end of the occluded coronary artery over the guidewire. Urokinase (5–10 wu) mixed with contrast agents was slowly injected into the occluded section of the coronary artery through the microcatheter. The intracoronary thrombus gradually dissolved in 3–17 min, and the effect of thrombolysis was visible in real time. Stents were then implanted according to the characteristics of the recanalized culprit lesion to achieve full revascularization. One patient experienced premature ventricular contraction during vascular revascularization, and no malignant arrhythmias were seen in any patient. No reflow or slow flow was not observed post PCI. Thrombolysis in myocardial infarction flow grade and myocardial blush grade post-primary PCI was 3 in all eight patients. No patients experienced bleeding or stroke. Conclusions ICART was accurate and effective for treating intracoronary thrombi in patients with STEMI in this preliminary study. ICART was an effective, feasible, and simple approach to the management of STEMI, and no intraprocedural complications occurred in any of the patients. ICART may be a breakthrough in the treatment of acute STEMI.展开更多
AIM:To assess the value of double-balloon enteroscopy(DBE) for the diagnosis of gastrointestinal mesenchymal tumors(GIMTs) in the small bowel and clarify their clinical and endoscopic characteristics.METHODS:A retrosp...AIM:To assess the value of double-balloon enteroscopy(DBE) for the diagnosis of gastrointestinal mesenchymal tumors(GIMTs) in the small bowel and clarify their clinical and endoscopic characteristics.METHODS:A retrospective review in a total of 783 patients who underwent a DBE procedure from January 2003 to December 2011 was conducted.Data from patients with pathologically confirmed GIMTs were analyzed at a single tertiary center with nine years' experience.The primary outcomes assessed included characteristics of patients with GIMTs,indications for DBE,overall diagnostic yield of GIMTs,endoscopic morphology,positive biopsy,comparison of diagnosis with capsule endoscopy,and subsequent interventional management.RESULTS:GIMTs were identified and analyzed in 77 patients.The mean age was 47.74 ± 14.14 years(range:20-77 years),with 63.6% being males.The majority of individuals presented with gastrointestinal bleeding,accounting for 81.8%,followed by abdominal pain,accounting for 10.4%.Small bowel pathologies were found in 71 patients,the detection rate was 92.2%.The diagnostic yield of DBE for GIMTs was 88.3%.DBE was superior to capsule endoscopy in the diagnosis of GIMTs(P = 0.006;McNemar's χ2 test).Gastrointestinal stromal tumor was the most frequent and leiomyoma was the second frequent GIMT.Single and focal lesions were typical of GIMTs,and masses with smooth or unsmooth surface were the most common in the small bowel.GIMTs were removed from all the patients surgically except one patient treated with endoscopic resection.CONCLUSION:DBE is a safe and valuable procedure for patients with suspected GIMTs,and it provides an accurate position for subsequent surgical intervention.展开更多
Objective To evaluate the clinical impact of whole body diffusion weighted imaging (WB-DWI) on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. WB-...Objective To evaluate the clinical impact of whole body diffusion weighted imaging (WB-DWI) on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. WB-DWI was performed by using short TI inversion recovery echo-planar imaging sequence with free breathing and built-in body coil. Axial T2- weighted imaging images of the same location were used as reference. The results of WB-DWI were compared with pathological results and other imaging modalities. The mean apparent diffusion coefficient (ADC) values of different kinds of lymph nodes were compared. Results WB-DWI was positive in all 18 cases with lymphoma, 5 cases with metastatic lymph nodes and 4 of 8 cases with benign lymphadenopathy. The mean ADC value of lymphomatous, metastatic and benign lymph nodes was (0.87 ± 0.17) × 10-3, (0.98 ± 0.09) × 10-3 and (1.20 ± 0.10) × 10-3 mm2/s. There was significant difference in ADC value between benign lymph nodes and other two groups (P < 0.01). The sensitivity, specificity and accuracy of WB-DWI in diagnosis of lymphoma were 100% (18/18), 30.8% (4/13) and 71.0% (22/31). When an ADC value of 1.08 × 10-3 mm2/s was used as the threshold value for differentiating malignant from benign lymph nodes, the best results were obtained with sensitivity of 87.8% and specificity of 91.3%. Sixteen of eighteen cases (88.9%) of lymphoma were accurately staged in accordance with clinical staging. Conclusions WB-DWI is a sensitive, but less specific technique for diagnosis of lymphoma. It is difficult to differentiate lymphomatous from metastatic lymph nodes using WB-DWI. However, it is a valuable imaging modality for staging of patients with malignant lymphoma.展开更多
Thrombotic thrombocytopenic purpura(TTP) is a multisystem disorder that essentially can affect any organ in the human body. The hallmark of the pathogenesis in TTP is the large von Willebrand factor multimers on plate...Thrombotic thrombocytopenic purpura(TTP) is a multisystem disorder that essentially can affect any organ in the human body. The hallmark of the pathogenesis in TTP is the large von Willebrand factor multimers on plateletmediated micro-thrombi formation, leading to microvascular thrombosis.Autopsy studies showed that cardiac arrest and myocardial infarction are the most common immediate causes of death in these patients. Clinical manifestations of cardiac involvement in TTP vary dramatically, from asymptomatic elevation of cardiac biomarkers, to heart failure, MI and sudden cardiac death. There is limited knowledge about optimal cardiac evaluation and management in patients with TTP. The absence of typical cardiac symptoms,combined with complicated multi-organ involvement in TTP, may contribute to the under-utilization of cardiac evaluation and treatment. Prompt diagnosis and timely initiation of effective therapy could be critically important in selected cases. Based on our experience and this review of the literature, we developed several recommendations for focused cardiac evaluation for patients with acute TTP:(1) patients with suspected or confirmed TTP should be screened for the potential presence of cardiac involvement with detailed history and physical,electrocardiogram and cardiac enzymes;(2) clinical deterioration of TTP patients warrants immediate cardiac reevaluation;(3) TTP patients with clinical evidence of cardiac involvement should be monitored for telemetry, cardiac biomarkers and evaluated with transthoracic echocardiography. These patients require urgent targeted TTP treatment as well as cardiac-specific treatment. Aspirin therapy is indicated for all TTP patients. Since epicardial coronary artery involvement is rare, cardiac catheterization is usually not required, given the high risk for hemorrhage and kidney injury;(4) we recommend evidence-based medical therapy for ischemic symptoms and heart failure. TTP patients with evidence of cardiac involvement would also benefit from routine cardiology follow up during remission.展开更多
Though weighted voting matching is one of most successful image matching methods, each candidate correspondence receives voting score from all other candidates, which can not apparently distinguish correct matches and...Though weighted voting matching is one of most successful image matching methods, each candidate correspondence receives voting score from all other candidates, which can not apparently distinguish correct matches and incorrect matches using voting scores. In this paper, a new image matching method based on mutual k-nearest neighbor (k-nn) graph is proposed. Firstly, the mutual k-nn graph is constructed according to similarity between candidate correspondences.Then, each candidate only receives voting score from its mutual k nearest neighbors. Finally, based on voting scores, the matching correspondences are computed by a greedy ranking technique. Experimental results demonstrate the effectiveness of the proposed method.展开更多
Effective language strategies play an essential role in traditional teaching.However,the benefits of nonverbal behavior teaching strategy in the classroom have been underestimated.Facial expressions,gestures,and eye c...Effective language strategies play an essential role in traditional teaching.However,the benefits of nonverbal behavior teaching strategy in the classroom have been underestimated.Facial expressions,gestures,and eye contact are all instantaneous nonverbal behaviors that play a significant part in exchanging information in classroom.This study aims to examine how different nonverbal teaching strategies affect teaching and learning and discover what it is used for and how important they are in education.Finally,some suggestions for improving teachers’use of nonverbal behaviors from a teacher professional development perspective are presented.展开更多
AIM:To evaluate the trends and changes in the number and rates of disability-adjusted life years(DALYs)and prevalence of cataract in China between 1990 and 2019,and to predict the trends of cataract burden from 2020 t...AIM:To evaluate the trends and changes in the number and rates of disability-adjusted life years(DALYs)and prevalence of cataract in China between 1990 and 2019,and to predict the trends of cataract burden from 2020 to 2030.METHODS:The Global Burden of Diseases(GBD)database was employed to collect the data on DALYs and the prevalence of cataract in China,which was distinguished by age and sex during the past three decades from 1990 to 2019,and then changes in the number and rates of cataract from 2020 to 2030 were predicted.All data were analyzed by the R program(version 4.2.2)and GraphPad Prism 9.0 statistics software.RESULTS:The number of DALYs of cataract increased from 449322.84 in 1990 to 1087987.61 in 2019,number of cataract cases increased from 5607600.94 in 1990 to 18142568.96 in 2019.The age-standardized DALY rates(ASDR)generally increased slightly[estimated annual percentage change(EAPC=0.1;95%CI:-0.24 to 0.45)],age-standardized prevalence rates(ASPR)also increased(EAPC=0.88;95%CI:0.6 to 1.15).Cataract burden increased with age and female gender.Among the causes of cataract,air pollution was the most important,followed by smoking,high fasting plasma glucose,and high body mass index(BMI).The burden of cataract is predicted to grow persistently from 2020 to 2030,the number of DALYs and prevalence for cataract will rise to 2336431 and 43698620 respectively by 2030,the ASDR is predicted to be 85/100000 and ASPR will be 1586/100000 in 2030,females will still be at greater risk of suffering from cataract than males.CONCLUSION:The burden of cataract in China kept rising from 1990 to 2019.Increasing age and female gender are risk factors for cataract.Air pollution,smoking,high fasting plasma glucose,and high BMI are associated with cataract.The burden of cataract in China will gradually increase from 2020 to 2030,the elderly women in particular need attention.Our results may be of help for providing reference strategies to reduce cataract burden in the near future.展开更多
The electrochemical oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) are fundamental processes in a range of energy conversion devices such as fuel cells and metal–air batteries. ORR and OER both hav...The electrochemical oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) are fundamental processes in a range of energy conversion devices such as fuel cells and metal–air batteries. ORR and OER both have significant activation barriers, which severely limit the overall performance of energy conversion devices that utilize ORR/OER. Meanwhile, ORR is another very important electrochemical reaction involving oxygen that has been widely investigated. ORR occurs in aqueous solutions via two pathways: the direct 4-electron reduction or 2-electron reduction pathways from O_(2) to water(H_2O) or from O_(2) to hydrogen peroxide(H_2O_(2)). Noble metal electrocatalysts are often used to catalyze OER and ORR, despite the fact that noble metal electrocatalysts have certain intrinsic limitations, such as low storage. Thus, it is urgent to develop more active and stable low-cost electrocatalysts, especially for severe environments(e.g., acidic media). Theoretically, an ideal oxygen electrocatalyst should provide adequate binding to oxygen species. Transition metals not belonging to the platinum group metal-based oxides are a low-cost substance that could give a d orbital for oxygen species binding. As a result, transition metal oxides are regarded as a substitute for typical precious metal oxygen electrocatalysts. However, the development of oxide catalysts for oxygen reduction and oxygen evolution reactions still faces significant challenges, e.g., catalytic activity, stability, cost, and reaction mechanism. We discuss the fundamental principles underlying the design of oxide catalysts, including the influence of crystal structure, and electronic structure on their performance. We also discuss the challenges associated with developing oxide catalysts and the potential strategies to overcome these challenges.展开更多
The tensile properties of 2297-T87 Al–Li alloy thick plates at different thickness position and in different direction were analyzed via tensile testing,optical microscopy(OM),X-ray diffraction(XRD),scanning electron...The tensile properties of 2297-T87 Al–Li alloy thick plates at different thickness position and in different direction were analyzed via tensile testing,optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).Results indicated that the ultimate tensile strength(UTS)and yield strength(YS)of the alloy decreased firstly and then increased from the 1/8T position to the 1/2T position,whereas elongation to failure(Ef)decreased gradually such that its value along the rolling direction(RD)was higher than those along the transverse direction(TD)at the same thickness position.From the 1/8T position to the 3/8T position of the alloy,the UTS and YS along the TD were higher than those along the RD.At the 1/2T position of the alloy,the UTS,YS,and Ef along the RD were the highest,whereas those along the normal direction(ND)were the lowest.Microstructural observations further revealed that the anisotropy of tensile properties was related to grain morphology,crystal texture,second-phase particles,and Li atom segregation.展开更多
The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characterist...The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characteristics of homoeologous pairing and recombination induced by phKL.In KL haploids,the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring(CS)haploids.There was a clear preference for A–D pairing and less frequent for A–B and B–D,reflecting the higher levels of affinity between genomes A and D in wheat.The characteristics of pairing were affected by temperature and magnesium ion supplementation.The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues:2Sv-2B,2Sv-2D,and 2RL-2BL.The recombination rates were 1.68%,0.17%,and 0%,respectively.The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present,both in wheat haploids and hexaploids.The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree,permitting homoeologous crossing over but only between closely related chromosomes;there was no crossing over between more differentiated chromosomes.Therefore,the phKL system(QPh.sicau-3A)can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.展开更多
Lignin is a natural polymer,second only to cellulose in natural reserves.Degradation is one of the ways to achieve the high-value transformation of lignin.Deep eutectic solvent(DES)thermal degradation of lignin can be...Lignin is a natural polymer,second only to cellulose in natural reserves.Degradation is one of the ways to achieve the high-value transformation of lignin.Deep eutectic solvent(DES)thermal degradation of lignin can be used as an excellent green degradation method.This paper introduces the degradation mechanism and effect of the lactic acid-choline chloride DES system in dissolving and degrading alkaline lignin,and the final solvent recovery.It can also be found from the scanning electron microscope(SEM)images that the surface of the degraded solid product is transformed from smooth to disordered.Fourier transform infrared(FTIR)spectroscopy and 1H-NMR spectroscopy were used to characterize the changes in lignin functional groups during DES treatment.The results showed that the content of phenolic hydroxyl groups increased after degradation,indicating that theβ-O-4 ether bond was broken.The molecular weight of the degraded lignin was observed by gel permeation chromatography(GPC),and the lignin residue with low molecular weight and narrow polydispersity index was obtained.The lowest average molecular weight(Mw)reached 2512 g/mol.The ratio of oxygen to carbon atoms in lignin increased substantially during degradation as measured by X-ray photoelectron spectroscopy(XPS),probably because DES treatment was accompanied by many oxidation reactions,which led to significant structural changes in lignin and a large number of ether bond breakage reactions during the reaction.The main final degradation products are aromatic monomers,vanillin,butyrovanillone,etc.展开更多
Transcatheter aortic valve replacement(TAVR)has emerged as an effective alternative to surgical aortic valve replacement in symptomatic aortic stenosis(AS).^([1,2])Approximately one in five cases of AS are emergent wi...Transcatheter aortic valve replacement(TAVR)has emerged as an effective alternative to surgical aortic valve replacement in symptomatic aortic stenosis(AS).^([1,2])Approximately one in five cases of AS are emergent with acute decompensation of cardiac function;^([3])therefore,emergent TAVR is an essential approach for severe AS patients with acute condition.展开更多
BACKGROUND Trehalose is a naturally occurring disaccharide,which has been identified as an autophagy inducer and ex-hibits protective effect in cardiovascular diseases such as myocardial infraction and atherosclerosis...BACKGROUND Trehalose is a naturally occurring disaccharide,which has been identified as an autophagy inducer and ex-hibits protective effect in cardiovascular diseases such as myocardial infraction and atherosclerosis.However,the functional role of trehalose in abdominal aortic aneurysm(AAA)remains undefined.METHODS To study the effect of trehalose in AAA,trehalose(1 g/kg per day)were given for 14 continuous days in a mouse model of elastase-induced abdominal aortic aneurysm.On day 14,ultrasound was performed to measure aortic diameter before the abdominal aortas were harvested and processed for further analysis.Verhoeff-Van Gieson staining and TUNEL staining were performed on paraffin sections to evaluate vascular histology and apoptosis,immunofluorescence staining and Western-blot were performed to evaluate expression of autophagy markers.RESULTS Echocardiography and in situ pictures demonstrated that trehalose attenuated infrarenal aorta dilation.Verhoeff-Van Gieson staining showed elastin degradation was improved in trehalose-treated group.Compared with vehicle-treated mice,trehalose treatment restored smooth muscle cell contractile phenotype with increasedα-SMA,Calponin and Myh11 expression.Furthermore,trehalose also attenuated cell apoptosis and leukocytes infiltration.Importantly,trehalose induced autophagy with decrease SQSTM1/p62 accumulation,increased lamp2 expression and LC3B conversion.CONCLUSION Trehalose attenuated AAA progression with decreased inflammation and restored SMC contractile phenotype by inducing autophagy.These results demonstrated the therapeutic potential of trehalose in AAA.展开更多
Along with the discovery and refinement of serrated pathways,the World Health Organization amended the classification of digestive system tumors in 2019,recommending the renaming of sessile serrated adenomas/polyps to...Along with the discovery and refinement of serrated pathways,the World Health Organization amended the classification of digestive system tumors in 2019,recommending the renaming of sessile serrated adenomas/polyps to sessile serrated lesions(SSLs).Given the particularity of the endoscopic appearance of SSLs,it could easily be overlooked and missed in colonoscopy screening,which is crucial for the occurrence of interval colorectal cancer.Existing literature has found that adequate bowel preparation,reasonable withdrawal time,and awareness of colorectal SSLs have improved the quality and accuracy of detection.More particularly,with the continuous advancement and development of endoscopy technology,equipment,and accessories,a potent auxiliary tool is provided for accurate observation and immediate diagnosis of SSLs.Highdefinition white light endoscopy,chromoendoscopy,and magnifying endoscopy have distinct roles in the detection of colorectal SSLs and are valuable in identifying the size,shape,character,risk degree,and potential malignant tendency.This article delves into the relevant factors influencing the detection rate of colorectal SSLs,reviews its characteristics under various endoscopic techniques,and expects to attract the attention of colonoscopists.展开更多
BACKGROUND Sessile serrated lesions(SSLs)are often missed on colonoscopy,and studies have shown this to be an essential cause of interstitial colorectal cancer.The SSLs with dysplasia(SSL-D+),in particular,have a fast...BACKGROUND Sessile serrated lesions(SSLs)are often missed on colonoscopy,and studies have shown this to be an essential cause of interstitial colorectal cancer.The SSLs with dysplasia(SSL-D+),in particular,have a faster rate of carcinogenesis than conventional tubular adenomas.Therefore,there is a clinical need for some endoscopic features with independent diagnostic value for SSL-D+s to assist endoscopists in making immediate diagnoses,thus improving the quality of endoscopic examination and treatment.AIM To compare the characteristics of SSLs,including those with and without dysplasia(SSL-D+and SSL-D-),based on white light and image-enhanced endoscopy,to achieve an immediate differential diagnosis for endoscopists.METHODS From January 2017 to February 2023,cases of colorectal SSLs confirmed by colonoscopy and histopathology at the Gastrointestinal Endoscopy Center of Beijing Tsinghua Changgung Hospital were collected.The general,endoscopic,and histopathological data were reviewed and analyzed to determine the diagnostic utility.Univariate analysis was used to find potential diagnostic factors,and then multivariate regression analysis was performed to derive endoscopic features with independent diagnostic values for the SSL-D+.RESULTS A total of 228 patients with 253 lesions were collected as a result.There were 225 cases of colorectal SSL-D-s and 28 cases of SSL-D+s.Compared to the colorectal SSL-D-,the SSL-D+was more common in the right colon(P=0.027)with complex patterns of depression,nodule,and elevation based on cloud-like surfaces(P=0.003),reddish(P<0.001),microvascular varicose(P<0.001),and mixed type(Pit II,II-O,IIIL,IV)of crypt opening based on Pit II-O(P<0.001).Multifactorial logistic regression analysis indicated that lesions had a reddish color[odds ratio(OR)=18.705,95%confidence interval(CI):3.684-94.974],microvascular varicose(OR=6.768,95%CI:1.717-26.677),and mixed pattern of crypt opening(OR=20.704,95%CI:2.955-145.086)as the independent predictors for SSL-D+s.CONCLUSION The endoscopic feature that has independent diagnostic value for SSL-D+is a reddish color,microvascular varicose,and mixed pattern of crypt openings.展开更多
The direct use of spent liquor from pulping and papermaking engineering,which is abundant in active organic matter,can avoid resource wastage and environmental pollution.In this study,the effects of soaking solution a...The direct use of spent liquor from pulping and papermaking engineering,which is abundant in active organic matter,can avoid resource wastage and environmental pollution.In this study,the effects of soaking solution and filtrate from steam-exploded rice straw on seed germination and the early development of cabbage were investigated.The results have shown that soaking solution and filtrate stimulated early cabbage growth at low concentrations.Optimal germination potential and the rate of soaking solution-treated cabbage seeds increased by 8%and 5%,respectively;meanwhile,that of the filtrate-treated cabbage seeds increased by 11%and 5%,respectively.Promotion of root growth by steam-exploded rice straw spent liquor was expressed in lateral root multiplication.The fresh weight of cabbage seedlings treated with the soaking solution/filtrate increased by more than 50%and the dry weight over 20%.Comparatively,the stimulation of filtrate on seed germination and early development of cabbage is superior to that of the soaking solution.Steam-exploded rice straw spent liquor is rich in bioactive lignin and oligosaccharides,which makes it a promising biostimulant for promoting crop growth.展开更多
The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were investigated.Hot compression and tenssion tests were carried ...The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were investigated.Hot compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate observations.Hot compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was better.The tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,respectively.The addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the deformability.In addition,the interaction between inclusions and microalloyed elements was also significant.NbC particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51704087)the Natural Science Foundation of Heilongjiang Province, China (No. LH2020E083)。
基金the National Natural Science Foundation of China(Grant No.52076028).
文摘Interfacial solar evaporation holds immense potential for brine desalination with low carbon footprints and high energy utilization.Hydrogels,as a tunable material platform from the molecular level to the macroscopic scale,have been considered the most promising candidate for solar evaporation.However,the simultaneous achievement of high evaporation efficiency and satisfactory tolerance to salt ions in brine remains a challenging scientific bottleneck,restricting the widespread application.Herein,we report ionization engineering,which endows polymer chains of hydrogels with electronegativity for impeding salt ions and activating water molecules,fundamentally overcoming the hydrogel salt-impeded challenge and dramatically expediting water evaporating in brine.The sodium dodecyl benzene sulfonate-modified carbon black is chosen as the solar absorbers.The hydrogel reaches a ground-breaking evaporation rate of 2.9 kg m−2 h−1 in 20 wt%brine with 95.6%efficiency under one sun irradiation,surpassing most of the reported literature.More notably,such a hydrogel-based evaporator enables extracting clean water from oversaturated salt solutions and maintains durability under different high-strength deformation or a 15-day continuous operation.Meantime,on the basis of the cation selectivity induced by the electronegativity,we first propose an all-day system that evaporates during the day and generates salinity-gradient electricity using waste-evaporated brine at night,anticipating pioneer a new opportunity for all-day resource-generating systems in fields of freshwater and electricity.
基金supported by the Hainan Province’s Key Research and Development Project(ZDYF 2017096&ZDYF2018118)National Natural Science Foundation of China(NSFC:81500202)+2 种基金Beijing Lisheng Cardiovascular Health Foundation Pilot Fund Project(LHJJ201610620)Provincial Key Science and Technology Projects supporting projects in Sanya(2018PT48)Sanya Medical and Health Science and Technology Innovation Project(2017YW10)
文摘Background Clearance of coronary arterial thrombosis is necessary in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing urgent percutaneous coronary intervention (PCI). There is currently no highly-recommended method of thrombus removal during interventional procedures. We describe a new method for opening culprit vessels to treat STEMI: intracoronary arterial retrograde thrombolysis (ICART) with PCI. Methods & Results Eight patients underwent ICART. The guidewire was advanced to the distal coronary artery through the occlusion lesion. Then, we inserted a microcatheter into the distal end of the occluded coronary artery over the guidewire. Urokinase (5–10 wu) mixed with contrast agents was slowly injected into the occluded section of the coronary artery through the microcatheter. The intracoronary thrombus gradually dissolved in 3–17 min, and the effect of thrombolysis was visible in real time. Stents were then implanted according to the characteristics of the recanalized culprit lesion to achieve full revascularization. One patient experienced premature ventricular contraction during vascular revascularization, and no malignant arrhythmias were seen in any patient. No reflow or slow flow was not observed post PCI. Thrombolysis in myocardial infarction flow grade and myocardial blush grade post-primary PCI was 3 in all eight patients. No patients experienced bleeding or stroke. Conclusions ICART was accurate and effective for treating intracoronary thrombi in patients with STEMI in this preliminary study. ICART was an effective, feasible, and simple approach to the management of STEMI, and no intraprocedural complications occurred in any of the patients. ICART may be a breakthrough in the treatment of acute STEMI.
文摘AIM:To assess the value of double-balloon enteroscopy(DBE) for the diagnosis of gastrointestinal mesenchymal tumors(GIMTs) in the small bowel and clarify their clinical and endoscopic characteristics.METHODS:A retrospective review in a total of 783 patients who underwent a DBE procedure from January 2003 to December 2011 was conducted.Data from patients with pathologically confirmed GIMTs were analyzed at a single tertiary center with nine years' experience.The primary outcomes assessed included characteristics of patients with GIMTs,indications for DBE,overall diagnostic yield of GIMTs,endoscopic morphology,positive biopsy,comparison of diagnosis with capsule endoscopy,and subsequent interventional management.RESULTS:GIMTs were identified and analyzed in 77 patients.The mean age was 47.74 ± 14.14 years(range:20-77 years),with 63.6% being males.The majority of individuals presented with gastrointestinal bleeding,accounting for 81.8%,followed by abdominal pain,accounting for 10.4%.Small bowel pathologies were found in 71 patients,the detection rate was 92.2%.The diagnostic yield of DBE for GIMTs was 88.3%.DBE was superior to capsule endoscopy in the diagnosis of GIMTs(P = 0.006;McNemar's χ2 test).Gastrointestinal stromal tumor was the most frequent and leiomyoma was the second frequent GIMT.Single and focal lesions were typical of GIMTs,and masses with smooth or unsmooth surface were the most common in the small bowel.GIMTs were removed from all the patients surgically except one patient treated with endoscopic resection.CONCLUSION:DBE is a safe and valuable procedure for patients with suspected GIMTs,and it provides an accurate position for subsequent surgical intervention.
文摘Objective To evaluate the clinical impact of whole body diffusion weighted imaging (WB-DWI) on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. WB-DWI was performed by using short TI inversion recovery echo-planar imaging sequence with free breathing and built-in body coil. Axial T2- weighted imaging images of the same location were used as reference. The results of WB-DWI were compared with pathological results and other imaging modalities. The mean apparent diffusion coefficient (ADC) values of different kinds of lymph nodes were compared. Results WB-DWI was positive in all 18 cases with lymphoma, 5 cases with metastatic lymph nodes and 4 of 8 cases with benign lymphadenopathy. The mean ADC value of lymphomatous, metastatic and benign lymph nodes was (0.87 ± 0.17) × 10-3, (0.98 ± 0.09) × 10-3 and (1.20 ± 0.10) × 10-3 mm2/s. There was significant difference in ADC value between benign lymph nodes and other two groups (P < 0.01). The sensitivity, specificity and accuracy of WB-DWI in diagnosis of lymphoma were 100% (18/18), 30.8% (4/13) and 71.0% (22/31). When an ADC value of 1.08 × 10-3 mm2/s was used as the threshold value for differentiating malignant from benign lymph nodes, the best results were obtained with sensitivity of 87.8% and specificity of 91.3%. Sixteen of eighteen cases (88.9%) of lymphoma were accurately staged in accordance with clinical staging. Conclusions WB-DWI is a sensitive, but less specific technique for diagnosis of lymphoma. It is difficult to differentiate lymphomatous from metastatic lymph nodes using WB-DWI. However, it is a valuable imaging modality for staging of patients with malignant lymphoma.
文摘Thrombotic thrombocytopenic purpura(TTP) is a multisystem disorder that essentially can affect any organ in the human body. The hallmark of the pathogenesis in TTP is the large von Willebrand factor multimers on plateletmediated micro-thrombi formation, leading to microvascular thrombosis.Autopsy studies showed that cardiac arrest and myocardial infarction are the most common immediate causes of death in these patients. Clinical manifestations of cardiac involvement in TTP vary dramatically, from asymptomatic elevation of cardiac biomarkers, to heart failure, MI and sudden cardiac death. There is limited knowledge about optimal cardiac evaluation and management in patients with TTP. The absence of typical cardiac symptoms,combined with complicated multi-organ involvement in TTP, may contribute to the under-utilization of cardiac evaluation and treatment. Prompt diagnosis and timely initiation of effective therapy could be critically important in selected cases. Based on our experience and this review of the literature, we developed several recommendations for focused cardiac evaluation for patients with acute TTP:(1) patients with suspected or confirmed TTP should be screened for the potential presence of cardiac involvement with detailed history and physical,electrocardiogram and cardiac enzymes;(2) clinical deterioration of TTP patients warrants immediate cardiac reevaluation;(3) TTP patients with clinical evidence of cardiac involvement should be monitored for telemetry, cardiac biomarkers and evaluated with transthoracic echocardiography. These patients require urgent targeted TTP treatment as well as cardiac-specific treatment. Aspirin therapy is indicated for all TTP patients. Since epicardial coronary artery involvement is rare, cardiac catheterization is usually not required, given the high risk for hemorrhage and kidney injury;(4) we recommend evidence-based medical therapy for ischemic symptoms and heart failure. TTP patients with evidence of cardiac involvement would also benefit from routine cardiology follow up during remission.
基金This work is supported by the National Natural Science Foundation of China (No. 61402002, 61472002) the Natural Science Foundation of Anhui Higher Education Institutions of China (No. KJ2014A015, KJ2013A007).
文摘Though weighted voting matching is one of most successful image matching methods, each candidate correspondence receives voting score from all other candidates, which can not apparently distinguish correct matches and incorrect matches using voting scores. In this paper, a new image matching method based on mutual k-nearest neighbor (k-nn) graph is proposed. Firstly, the mutual k-nn graph is constructed according to similarity between candidate correspondences.Then, each candidate only receives voting score from its mutual k nearest neighbors. Finally, based on voting scores, the matching correspondences are computed by a greedy ranking technique. Experimental results demonstrate the effectiveness of the proposed method.
文摘Effective language strategies play an essential role in traditional teaching.However,the benefits of nonverbal behavior teaching strategy in the classroom have been underestimated.Facial expressions,gestures,and eye contact are all instantaneous nonverbal behaviors that play a significant part in exchanging information in classroom.This study aims to examine how different nonverbal teaching strategies affect teaching and learning and discover what it is used for and how important they are in education.Finally,some suggestions for improving teachers’use of nonverbal behaviors from a teacher professional development perspective are presented.
文摘AIM:To evaluate the trends and changes in the number and rates of disability-adjusted life years(DALYs)and prevalence of cataract in China between 1990 and 2019,and to predict the trends of cataract burden from 2020 to 2030.METHODS:The Global Burden of Diseases(GBD)database was employed to collect the data on DALYs and the prevalence of cataract in China,which was distinguished by age and sex during the past three decades from 1990 to 2019,and then changes in the number and rates of cataract from 2020 to 2030 were predicted.All data were analyzed by the R program(version 4.2.2)and GraphPad Prism 9.0 statistics software.RESULTS:The number of DALYs of cataract increased from 449322.84 in 1990 to 1087987.61 in 2019,number of cataract cases increased from 5607600.94 in 1990 to 18142568.96 in 2019.The age-standardized DALY rates(ASDR)generally increased slightly[estimated annual percentage change(EAPC=0.1;95%CI:-0.24 to 0.45)],age-standardized prevalence rates(ASPR)also increased(EAPC=0.88;95%CI:0.6 to 1.15).Cataract burden increased with age and female gender.Among the causes of cataract,air pollution was the most important,followed by smoking,high fasting plasma glucose,and high body mass index(BMI).The burden of cataract is predicted to grow persistently from 2020 to 2030,the number of DALYs and prevalence for cataract will rise to 2336431 and 43698620 respectively by 2030,the ASDR is predicted to be 85/100000 and ASPR will be 1586/100000 in 2030,females will still be at greater risk of suffering from cataract than males.CONCLUSION:The burden of cataract in China kept rising from 1990 to 2019.Increasing age and female gender are risk factors for cataract.Air pollution,smoking,high fasting plasma glucose,and high BMI are associated with cataract.The burden of cataract in China will gradually increase from 2020 to 2030,the elderly women in particular need attention.Our results may be of help for providing reference strategies to reduce cataract burden in the near future.
基金the Natural Science Foundation of China (22005250)National Key R D Program of China (2022YFB2502000)FWO (12ZV320N)。
文摘The electrochemical oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) are fundamental processes in a range of energy conversion devices such as fuel cells and metal–air batteries. ORR and OER both have significant activation barriers, which severely limit the overall performance of energy conversion devices that utilize ORR/OER. Meanwhile, ORR is another very important electrochemical reaction involving oxygen that has been widely investigated. ORR occurs in aqueous solutions via two pathways: the direct 4-electron reduction or 2-electron reduction pathways from O_(2) to water(H_2O) or from O_(2) to hydrogen peroxide(H_2O_(2)). Noble metal electrocatalysts are often used to catalyze OER and ORR, despite the fact that noble metal electrocatalysts have certain intrinsic limitations, such as low storage. Thus, it is urgent to develop more active and stable low-cost electrocatalysts, especially for severe environments(e.g., acidic media). Theoretically, an ideal oxygen electrocatalyst should provide adequate binding to oxygen species. Transition metals not belonging to the platinum group metal-based oxides are a low-cost substance that could give a d orbital for oxygen species binding. As a result, transition metal oxides are regarded as a substitute for typical precious metal oxygen electrocatalysts. However, the development of oxide catalysts for oxygen reduction and oxygen evolution reactions still faces significant challenges, e.g., catalytic activity, stability, cost, and reaction mechanism. We discuss the fundamental principles underlying the design of oxide catalysts, including the influence of crystal structure, and electronic structure on their performance. We also discuss the challenges associated with developing oxide catalysts and the potential strategies to overcome these challenges.
基金supported by the National Natural Science Foundation of China(31772042)Ramóny Cajal grant(RYC2020-030365-I)+1 种基金Xunta de Galicia for supporting the program(Excelencia-ED431F2022/01)the Key Research&Development Program of Zhejiang Province(2021C02015).
基金financially supported by the National Natural Science Foundation of China(Nos.52171029,51671038)the Major Natural Science Research Project of Higher Education Institutions in Jiangsu Province(No.18KJA430002)。
文摘The tensile properties of 2297-T87 Al–Li alloy thick plates at different thickness position and in different direction were analyzed via tensile testing,optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).Results indicated that the ultimate tensile strength(UTS)and yield strength(YS)of the alloy decreased firstly and then increased from the 1/8T position to the 1/2T position,whereas elongation to failure(Ef)decreased gradually such that its value along the rolling direction(RD)was higher than those along the transverse direction(TD)at the same thickness position.From the 1/8T position to the 3/8T position of the alloy,the UTS and YS along the TD were higher than those along the RD.At the 1/2T position of the alloy,the UTS,YS,and Ef along the RD were the highest,whereas those along the normal direction(ND)were the lowest.Microstructural observations further revealed that the anisotropy of tensile properties was related to grain morphology,crystal texture,second-phase particles,and Li atom segregation.
基金supported by the National Natural Science Foundation of China(31971884,31601300,32172020)USDANIFA(#CA-R-BPS-5411-H)to AJL+1 种基金Natural Science Foundation of Sichuan Province(2022NSFSC1696,2019YJ0415)the National Key Research and Development Program of China(2016YFD0102000)。
文摘The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characteristics of homoeologous pairing and recombination induced by phKL.In KL haploids,the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring(CS)haploids.There was a clear preference for A–D pairing and less frequent for A–B and B–D,reflecting the higher levels of affinity between genomes A and D in wheat.The characteristics of pairing were affected by temperature and magnesium ion supplementation.The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues:2Sv-2B,2Sv-2D,and 2RL-2BL.The recombination rates were 1.68%,0.17%,and 0%,respectively.The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present,both in wheat haploids and hexaploids.The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree,permitting homoeologous crossing over but only between closely related chromosomes;there was no crossing over between more differentiated chromosomes.Therefore,the phKL system(QPh.sicau-3A)can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.
基金This work was financially supported by the National Natural Science Foundation of China(31730106).
文摘Lignin is a natural polymer,second only to cellulose in natural reserves.Degradation is one of the ways to achieve the high-value transformation of lignin.Deep eutectic solvent(DES)thermal degradation of lignin can be used as an excellent green degradation method.This paper introduces the degradation mechanism and effect of the lactic acid-choline chloride DES system in dissolving and degrading alkaline lignin,and the final solvent recovery.It can also be found from the scanning electron microscope(SEM)images that the surface of the degraded solid product is transformed from smooth to disordered.Fourier transform infrared(FTIR)spectroscopy and 1H-NMR spectroscopy were used to characterize the changes in lignin functional groups during DES treatment.The results showed that the content of phenolic hydroxyl groups increased after degradation,indicating that theβ-O-4 ether bond was broken.The molecular weight of the degraded lignin was observed by gel permeation chromatography(GPC),and the lignin residue with low molecular weight and narrow polydispersity index was obtained.The lowest average molecular weight(Mw)reached 2512 g/mol.The ratio of oxygen to carbon atoms in lignin increased substantially during degradation as measured by X-ray photoelectron spectroscopy(XPS),probably because DES treatment was accompanied by many oxidation reactions,which led to significant structural changes in lignin and a large number of ether bond breakage reactions during the reaction.The main final degradation products are aromatic monomers,vanillin,butyrovanillone,etc.
基金supported by the National Key Research and Development Program of China(2016YFC1300304)the Logistic Health Care Program(21BJZ33)the Youth Independent Innovation Science Fund of Chinese PLA General Hospital(22QNCZ024).
文摘Transcatheter aortic valve replacement(TAVR)has emerged as an effective alternative to surgical aortic valve replacement in symptomatic aortic stenosis(AS).^([1,2])Approximately one in five cases of AS are emergent with acute decompensation of cardiac function;^([3])therefore,emergent TAVR is an essential approach for severe AS patients with acute condition.
基金supported by National Natural Science Foundation of China(grant no.81974049).
文摘BACKGROUND Trehalose is a naturally occurring disaccharide,which has been identified as an autophagy inducer and ex-hibits protective effect in cardiovascular diseases such as myocardial infraction and atherosclerosis.However,the functional role of trehalose in abdominal aortic aneurysm(AAA)remains undefined.METHODS To study the effect of trehalose in AAA,trehalose(1 g/kg per day)were given for 14 continuous days in a mouse model of elastase-induced abdominal aortic aneurysm.On day 14,ultrasound was performed to measure aortic diameter before the abdominal aortas were harvested and processed for further analysis.Verhoeff-Van Gieson staining and TUNEL staining were performed on paraffin sections to evaluate vascular histology and apoptosis,immunofluorescence staining and Western-blot were performed to evaluate expression of autophagy markers.RESULTS Echocardiography and in situ pictures demonstrated that trehalose attenuated infrarenal aorta dilation.Verhoeff-Van Gieson staining showed elastin degradation was improved in trehalose-treated group.Compared with vehicle-treated mice,trehalose treatment restored smooth muscle cell contractile phenotype with increasedα-SMA,Calponin and Myh11 expression.Furthermore,trehalose also attenuated cell apoptosis and leukocytes infiltration.Importantly,trehalose induced autophagy with decrease SQSTM1/p62 accumulation,increased lamp2 expression and LC3B conversion.CONCLUSION Trehalose attenuated AAA progression with decreased inflammation and restored SMC contractile phenotype by inducing autophagy.These results demonstrated the therapeutic potential of trehalose in AAA.
文摘Along with the discovery and refinement of serrated pathways,the World Health Organization amended the classification of digestive system tumors in 2019,recommending the renaming of sessile serrated adenomas/polyps to sessile serrated lesions(SSLs).Given the particularity of the endoscopic appearance of SSLs,it could easily be overlooked and missed in colonoscopy screening,which is crucial for the occurrence of interval colorectal cancer.Existing literature has found that adequate bowel preparation,reasonable withdrawal time,and awareness of colorectal SSLs have improved the quality and accuracy of detection.More particularly,with the continuous advancement and development of endoscopy technology,equipment,and accessories,a potent auxiliary tool is provided for accurate observation and immediate diagnosis of SSLs.Highdefinition white light endoscopy,chromoendoscopy,and magnifying endoscopy have distinct roles in the detection of colorectal SSLs and are valuable in identifying the size,shape,character,risk degree,and potential malignant tendency.This article delves into the relevant factors influencing the detection rate of colorectal SSLs,reviews its characteristics under various endoscopic techniques,and expects to attract the attention of colonoscopists.
基金The study was reviewed and approved by the Beijing Tsinghua Changgung Hospital Institutional Review Board(approval No.21439-0-02).
文摘BACKGROUND Sessile serrated lesions(SSLs)are often missed on colonoscopy,and studies have shown this to be an essential cause of interstitial colorectal cancer.The SSLs with dysplasia(SSL-D+),in particular,have a faster rate of carcinogenesis than conventional tubular adenomas.Therefore,there is a clinical need for some endoscopic features with independent diagnostic value for SSL-D+s to assist endoscopists in making immediate diagnoses,thus improving the quality of endoscopic examination and treatment.AIM To compare the characteristics of SSLs,including those with and without dysplasia(SSL-D+and SSL-D-),based on white light and image-enhanced endoscopy,to achieve an immediate differential diagnosis for endoscopists.METHODS From January 2017 to February 2023,cases of colorectal SSLs confirmed by colonoscopy and histopathology at the Gastrointestinal Endoscopy Center of Beijing Tsinghua Changgung Hospital were collected.The general,endoscopic,and histopathological data were reviewed and analyzed to determine the diagnostic utility.Univariate analysis was used to find potential diagnostic factors,and then multivariate regression analysis was performed to derive endoscopic features with independent diagnostic values for the SSL-D+.RESULTS A total of 228 patients with 253 lesions were collected as a result.There were 225 cases of colorectal SSL-D-s and 28 cases of SSL-D+s.Compared to the colorectal SSL-D-,the SSL-D+was more common in the right colon(P=0.027)with complex patterns of depression,nodule,and elevation based on cloud-like surfaces(P=0.003),reddish(P<0.001),microvascular varicose(P<0.001),and mixed type(Pit II,II-O,IIIL,IV)of crypt opening based on Pit II-O(P<0.001).Multifactorial logistic regression analysis indicated that lesions had a reddish color[odds ratio(OR)=18.705,95%confidence interval(CI):3.684-94.974],microvascular varicose(OR=6.768,95%CI:1.717-26.677),and mixed pattern of crypt opening(OR=20.704,95%CI:2.955-145.086)as the independent predictors for SSL-D+s.CONCLUSION The endoscopic feature that has independent diagnostic value for SSL-D+is a reddish color,microvascular varicose,and mixed pattern of crypt openings.
基金the financial support from the National Natural Science Foundation of China(Grant No.32201500,32271797,32271811)Natural Science Foundation of Jiangsu Province(Grant No.BK20220431)+2 种基金Jiangsu Provincial Key Research and Development Program(Grant No.BE2021368)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.21KJB220001)Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials(Grant No.2022KFJJ05).
文摘The direct use of spent liquor from pulping and papermaking engineering,which is abundant in active organic matter,can avoid resource wastage and environmental pollution.In this study,the effects of soaking solution and filtrate from steam-exploded rice straw on seed germination and the early development of cabbage were investigated.The results have shown that soaking solution and filtrate stimulated early cabbage growth at low concentrations.Optimal germination potential and the rate of soaking solution-treated cabbage seeds increased by 8%and 5%,respectively;meanwhile,that of the filtrate-treated cabbage seeds increased by 11%and 5%,respectively.Promotion of root growth by steam-exploded rice straw spent liquor was expressed in lateral root multiplication.The fresh weight of cabbage seedlings treated with the soaking solution/filtrate increased by more than 50%and the dry weight over 20%.Comparatively,the stimulation of filtrate on seed germination and early development of cabbage is superior to that of the soaking solution.Steam-exploded rice straw spent liquor is rich in bioactive lignin and oligosaccharides,which makes it a promising biostimulant for promoting crop growth.
基金The authors appreciate the financial support from Xining Special Steel Co.,Ltd.and student research training project of University of Science and Technology Beijing.
文摘The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were investigated.Hot compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate observations.Hot compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was better.The tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,respectively.The addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the deformability.In addition,the interaction between inclusions and microalloyed elements was also significant.NbC particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.
