Biochar have received multidisciplinary attention because of their extraordinary physicochemical properties.In this review,the application of biochar and biochar-based materials for the efficient elimination of organi...Biochar have received multidisciplinary attention because of their extraordinary physicochemical properties.In this review,the application of biochar and biochar-based materials for the efficient elimination of organic and inorganic pollutants are summarized.The sorption of organic chemicals and heavy metal ions/radionuclides,degradation/transformation of organic pollutants,and sorption-reduction-solidification of high-valent metal ions are described in detail.The interaction mechanism at molecular level from advanced spectroscopic techniques and theoretical calculations is discussed.Finally,the challenges in the application of biochar and biochar-supported materials in the immobilization of heavy metal ions and photocatalytic degradation of persistent organic pollutants in soils or wastewater are pointed out.This review is helpful for the graduate stu-dents to understand the recent works about biochar and biochar-supported materials in environmental pollutants management.展开更多
Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dis- solved sulfide (S2- and HS-) in wastewaters and as H2S in waste gases. Due to its corrosive nature, ...Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dis- solved sulfide (S2- and HS-) in wastewaters and as H2S in waste gases. Due to its corrosive nature, biological hydrogen sulfide removal processes are being investigated to overcome the chemical and disposal costs associated with existing chemically based removal processes. The nitrogen and sulfur metabolism interacts at various levels of the wastewater treatment process. Hence, the sulfur cycle offers possibilities to integrate nitrogen removal in the treatment process, which needs to be further optimized by appropriate design of the reactor configuration, optimization of performance parameters, retention of biomass and optimization of biomass growth. The present paper reviews the biotechnological advances to remove sulfides from various environments.展开更多
Application of silicon(Si) could greatly boost rice yield and mitigate abiotic stress,especially drought.A field experiment was conducted during 2015 at the research farm of Hong Duc University,Thanh Hoa City,Vietnam,...Application of silicon(Si) could greatly boost rice yield and mitigate abiotic stress,especially drought.A field experiment was conducted during 2015 at the research farm of Hong Duc University,Thanh Hoa City,Vietnam,to evaluate the effects of five different combined doses of standard fertilizer practice and Si fertilizer on growth,yield and yield components,as well as nutrient uptake of rice.The treatments consisted of the recommended dose of fertilizer(RDF,110 kg/hm^2 N + 90 kg/hm^2 P_2O_5 + 80 kg/hm^2 K_2O) as the control,RDF + 100 kg/hm^2 SiO_2,RDF + 200 kg/hm^2 SiO_2,RDF + 300 kg/hm^2 SiO_2 and RDF + 400 kg/hm^2 SiO_2.The results showed that the growth,grain and straw yields as well as yield components(number of grains per panicle,seed-setting rate and 1000-grain weight) were significantly affected by Si application.The highest grain yield of 3 705 kg/hm^2 was obtained with the highest level of Si fertilizer in combination with RDF(RDF + 400 kg/hm^2 SiO_2),however,it was statistically at par with the yields obtained with RDF + 300 kg/hm^2 SiO_2(3 664 kg/hm^2) and RDF + 200 kg/hm^2 SiO_2(3 621 kg/hm^2).The optimum dose of Si fertilizer with maximized grain yield(3 716 kg/hm^2) was 329 kg/hm^2 SiO_2.The nutrient(Si,N,P and K) uptakes of rice were also significantly enhanced by Si application.Si application at the level of 329 kg/hm^2 along with RDF would help in the sustainable production of rice in the tropical zone of Vietnam.展开更多
Seeds of Indian mustard （Brassicajuncea （L.） Czern. et Coss.） were exposed to 0, 50, 100 and 150 mmol/L NaCI for 8 h and seeds were sown in an earthen pot. These stressed seedlings were subsequently sprayed with 1...Seeds of Indian mustard （Brassicajuncea （L.） Czern. et Coss.） were exposed to 0, 50, 100 and 150 mmol/L NaCI for 8 h and seeds were sown in an earthen pot. These stressed seedlings were subsequently sprayed with 10μmol/L salicylic acid （SA） at 30 d and were sampled at 60 d to assess the changes in growth, photosynthesis and antioxidant enzymes. The seedlings raised from the seeds treated with NaCI had significantly reduced growth and the activities of carbonic anhydrase, nitrate reductase and photosynthesis, and the decrease was proportional to the increase in NaCI concentration. However, the antioxidant enzymes （catalase, peroxidase and superoxide dismutase） and proline content was enhanced in response to NaCI and/or SA treatment, where their interaction had an additive effect. Moreover, the toxic effects generated by the lower concentration of NaCI （50 mmol/L） were completely overcome by the application of SA. It was, therefore, concluded that SA ameliorated the stress generated by NaCl through the alleviated antioxidant system.展开更多
With the fast development of nanoscience and nanotechnology,the nanomaterials have attracted multidisciplinary interests.The high specific surface area and large numbers of oxygen-containing functional groups of graph...With the fast development of nanoscience and nanotechnology,the nanomaterials have attracted multidisciplinary interests.The high specific surface area and large numbers of oxygen-containing functional groups of graphene oxides(GOs) make them suitable in the preconcentration and solidification of radionuclides from wastewater.In this paper,mainly based on the recent work carried out in our laboratory,the efficient elimination of radionuclides using GOs and GO-based nanomaterials as adsorbents are summarized and the interaction mechanisms are discussed from the results of batch techniques,surface complexation modeling,spectroscopic analysis and theoretical calculations.This review is helpful for the understanding of the interactions of radionuclides with GOs and GO-based nanomaterials,which is also crucial for the application of GOs and GO-based nanomaterials in environmental radionuclide pollution management and also helpful in nuclear waste management.展开更多
The intrinsic growth ability of all the neurons declines during development although some may grow better than others. Numerous intracellular signaling proteins and transcription factors have been shown to regulate th...The intrinsic growth ability of all the neurons declines during development although some may grow better than others. Numerous intracellular signaling proteins and transcription factors have been shown to regulate the intrinsic growth capacity in mature neurons. Among them, PI3 kinase/Akt pathway is important for controlling axon elongation. As a negative regulator of this pathway, the tumor suppressor phosphatase and tensin homolog （PTEN） appears critical to con- trol the regenerative ability of young and adult neurons. This review will focus on recent research progress in axon regeneration and neural repair by PTEN inhibition and therapeutic potential of blocking this phosphatase for neurological disorders. Inhibition of PTEN by deletion in con- ditional knockout mice, knockdown by short-hairpin RNA, or blockade by pharmacological approaches, including administration of selective PTEN antagonist peptides, stimulates various degrees of axon regrowth in juvenile or adult rodents with central nervous system injuries. Im- portantly, post-injury PTEN suppression could enhance axonal growth and functional recovery in adult central nervous system after injury.展开更多
Grade A （GA） and high strength steel DH36 ship steels possessing different chemical compositions were used, and strength properties of GA steel and DH36 steel were compared. Additionally, 4 types of dual phase （DP...Grade A （GA） and high strength steel DH36 ship steels possessing different chemical compositions were used, and strength properties of GA steel and DH36 steel were compared. Additionally, 4 types of dual phase （DP） steels with different martensite volume fractions （MVFs） were produced from GA steel by means of heat treatment and they were compared with other steels through conducting mierostructure, microhardness, tensile and impact tests. The fracture surfaces of specimens （DH36, GA and DP steels） exposed to tensile and Charpy impact tests were investigated by scanning electron microscope. Furthermore, it was found that the specimens quenched from 800 and 900℃ had better strength than DH36 steel. The tensile test results indicated that the tensile strength of DP steel water quenched from 900℃ was 3 times that of GA steel and twice that of DH36 steel.展开更多
An extremely effortless method was applied for successful synthesis of mesoporous carbonaceous materials(MCMs) using well-ordered mesoporous silica as template. Various characterizations(scanning electron microscopy(S...An extremely effortless method was applied for successful synthesis of mesoporous carbonaceous materials(MCMs) using well-ordered mesoporous silica as template. Various characterizations(scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), Raman, X-ray photoelectron spectroscopy(XPS), Brunner-Emmet-Teller(BET) and Zeta potential) confirmed that MCMs had large surface area, uniform pore size distribution, and abundant oxygen-containing functional groups. The batch techniques were employed to study U(VI) adsorption on MCMs under a wide range of experiment conditions. The adsorption kinetics of U(VI) onto MCMs were well-fitted by pseudo-second-order kinetic model, indicating a chemisorption process. The excellent adsorption capacity of MCMs calculated from the Langmuir model was 293.95 mg g^(-1) at pH 4.0. The FT-IR and XPS analyses further evidenced that the binding of U(VI) onto MCMs was ascribed to the plentiful adsorption sites(–OH and –COOH groups) in the internal mesoporous structure, which could efficiently trap guest U(VI) ions. The results presented herein revealed that MCMs were ideal adsorbents in the efficient elimination of uranium or other lanthanides/actinides from aqueous solutions, which would play an important role in environmental pollution management application.展开更多
The effects of sub-transus(α+β)annealing treatment(ST),followed by single aging(SA)or duplex aging(DA)on the microstructural evolution and mechanical properties of near-βTi-4Al-1Sn-2Zr-5Mo-8V-2.5Cr(mass fraction,%)...The effects of sub-transus(α+β)annealing treatment(ST),followed by single aging(SA)or duplex aging(DA)on the microstructural evolution and mechanical properties of near-βTi-4Al-1Sn-2Zr-5Mo-8V-2.5Cr(mass fraction,%)alloy were investigated using optical microscopy,scanning electron microscopy,and transmission electron microscopy.The results show that the finer secondaryαphase precipitates in the alloy after DA than SA(e.g.,149 nm for SA and 69 nm for DA,both after ST at 720℃).The main reason is that the pre-aging step(300℃)in the DA process leads to the formation of intermediateωphase nanoparticles,which assist in the nucleation of the acicular secondaryαphase precipitates.In addition,the strength of the alloy after DA is higher than that of SA at the specific ST temperature.A good combination is achieved in the alloy subjected to ST at 750℃,followed by DA(UTS:1450 MPa,EL:3.87%),which is due to the precipitation of nanoscale secondaryαphase by DA.In conclusion,DA is a feasible process for this new near-βtitanium alloy.展开更多
Zinc coated dual phase 600 steel （DP 600 grade） was investigated, utilisation of which has gradually increased with each passing day in the automotive industry. The adhesive bonding （AB）, resistance spot welding ...Zinc coated dual phase 600 steel （DP 600 grade） was investigated, utilisation of which has gradually increased with each passing day in the automotive industry. The adhesive bonding （AB）, resistance spot welding （RSW）, and adhesive weld bonding （AWB） ioints of the zinc coated DP 600 steel were investigated. Additionally, the zinc coating was removed using HCL acid in order to investigate the effect of the coating. The microstructure, tensile shear strengths, and fracture properties of adhesive bonding （AB）, resistance spot welding （RSW）, and adhesive weld bonding （AWB） joints of the coated and uncoated DP 600 steel were compared. In addition, a mechani cal-electrical-thermal coupled model in a finite element analysis environment was utilised. The thermal profile phe nomenon was calculated by simulating this process. The results of the tensile shear test indicated that the tensile load bearing capacity （TLBC） values of the coated specimens among the three welding methods were higher than those of the uncoated specimens. Additionally, the tensile strength of the AWB joints of the coated and uncoated specimens was higher than that of the AB and RSW joints. It was determined that the fracture behaviours and the deformation caused were different for the three welding methods.展开更多
AIM: To assess and compare the esophageal function after peroral endoscopic myotomy(POEM) vs other conventional treatments in achalasia.METHODS: Chart review of all achalasia patients who underwent POEM, laparoscopic ...AIM: To assess and compare the esophageal function after peroral endoscopic myotomy(POEM) vs other conventional treatments in achalasia.METHODS: Chart review of all achalasia patients who underwent POEM, laparoscopic Heller myotomy(LHM) or pneumatic dilation(PD) at our institution between January 2012 and March 2015 was performed. Patient demographics, type of achalasia, prior treatments, pre- and post-treatment timed barium swallow(TBE) and high-resolution esophageal manometry(HREM) findings were compared between the three treatment groups. Patients who had both pre- and 2 mo posttreatment TBE or HREM were included in the final analysis. TBE parameters compared were barium column height, width and volume of barium remaining at 1 and 5 min. HREM parameters compared were basal lower esophageal sphincter(LES) pressures and LES-integrated relaxation pressures(IRP). Data are presented as mean ± SD, median [25th, 75 th percentiles] or frequency(percent). Analysis of variance, KruskalWallis test, Pearsons χ~2 test and Fishers Exact tests were used for analysis.RESULTS: A total of 200 achalasia patients were included of which 36 underwent POEM, 22 underwent PD and 142 underwent LHM. POEM patients were older(55.4 ± 16.8 years vs 46.5 ± 15.7 years, P = 0.013) and had higher BMI than LHM(29.1 ± 5.9 kg/m^2 vs 26 ± 5.1 kg/m^2, P = 0.012). More number of patients in POEM and PD groups had undergone prior treatments compared to LHM group(72.2% vs 68.2% vs 44.3% respectively, P = 0.003). At 2 mo post-treatment, all TBE parameters including barium column height, width and volume remaining at 1 and 5 min improved significantly in all three treatment groups(P = 0.01 to P < 0.001) except the column height at 1 min in PD group(P = 0.11). At 2 mo post-treatment, there was significant improvement in basal LES pressure and LES-IRP in both LHM(40.5 mm Hg vs 14.5 mm Hg and 24 mm Hg vs 7.1 mm Hg respectively, P < 0.001) and POEM groups(38.7 mm Hg vs 11.4 mm Hg and 23.6 mm Hg vs 6.6 mm Hg respectively, P < 0.001). However, when the e展开更多
Trace metals such as manganese(Mn),copper(Cu),zinc(Zn),and iron(Fe)are essential for many biological processes in plant life cycles.However,in excess,they can be toxic and disrupt plant growth processes,which is econo...Trace metals such as manganese(Mn),copper(Cu),zinc(Zn),and iron(Fe)are essential for many biological processes in plant life cycles.However,in excess,they can be toxic and disrupt plant growth processes,which is economically undesirable for crop production.For this reason,processes such as homeostasis and transport control of these trace metals are of constant interest to scientists studying heavily contaminated habitats.Phytoremediation is a promising cleanup technology for soils polluted with heavy metals.However,this technique has some disadvantages,such as the slow growth rate of metal-accumulating plant species,low bioavailability of heavy metals,and long duration of remediation.Microbial-assisted phytoremediation is a promising strategy for hyperaccumulating,detoxifying,or remediating soil contaminants.Arbuscular mycorrhizal fungi(AMF)are found in association with almost all plants,contributing to their healthy performance and providing resistance against environmental stresses.They colonize plant roots and extend their hyphae to the rhizosphere region,assisting in mineral nutrient uptake and regulation of heavy metal acquisition.Endophytic fungi exist in every healthy plant tissue and provide enormous services to their host plants,including growth enhancement by nutrient acquisition,detoxification of heavy metals,secondary metabolite regulation,and enhancement of abiotic/biotic stress tolerance.The aim of the present work is to review the recent literature regarding the role of AMF and endophytic fungi in plant heavy metal tolerance in terms of its regulation in highly contaminated conditions.展开更多
Introduction: The impact of pregnancy on the prognosis of papillary thyroid carcinoma (PTC) has been debated for several decades;however, no definitive conclusions have been reached. The main objective of this study i...Introduction: The impact of pregnancy on the prognosis of papillary thyroid carcinoma (PTC) has been debated for several decades;however, no definitive conclusions have been reached. The main objective of this study is to demonstrate the short-term influence of pregnancy on the evolution and prognosis of PTC. Materials and Methods: A prospective descriptive and analytical study was conducted in the Endocrinology and Diabetology Department at the Hassan II University Hospital in Fez, including patients followed for papillary thyroid carcinoma presenting with a pregnancy during the year 2019 and 2020. The follow-up of these patients was continued until 1 year postpartum. We studied the clinical, paraclinical and therapeutic factors that could influence the prognosis of the disease. Results: We included 26 patients. Our study showed a significant correlation between recurrence and the presence of unfavorable histological signs (p = 0.02) as well as the initial Tg level (0.01). However, pregnancy was not an influencing factor (p = 0.41). Conclusion: Pregnancy does not seem to be a factor aggravating the prognosis of differentiated thyroid cancers.展开更多
Background: Menopause is a period where natural cessation of menses occurs, some quality of life characteristics changes with some symptoms associated with this time such as hot flushes and anxiety. Objective: To eval...Background: Menopause is a period where natural cessation of menses occurs, some quality of life characteristics changes with some symptoms associated with this time such as hot flushes and anxiety. Objective: To evaluate and specify the level of impact of these symptoms on the quality of life among women in the Qatif area, Saudi Arabia and to study the factors that may involve in their perception. Methods: A cross-sectional study was conducted of 151 women aged 40 - 60 years old interviewed at either hospital or PHCs, a translated and revised questionnaire of other studies with some adoption. Results: 151 women out of 200 participated in questionnaires, majority of them were highly educated having at least a bachelor’s degree around 80%, and around 75% of participants were either working or retired, with a moderate level of income and enjoying a good lifestyle 93% in around and 97% in the after menopause. With the majority, were not used hormones 95% or conceptive pills 91%, personal perception of health were high around 93% for around and 97.2% for after menopause with no significant statistical difference between the two groups. Conclusion: Perception and knowledge of menopause were very high, with no differences in the severity of symptoms of the four QOL domains for the around or after menopause among the participants. High level of education and increased level of income and knowledge of the participants may play an important role in the result, so further investigation is advised.展开更多
基金Financial supports from National Key Research and Development Program of China(2018YFC1900105)National Natural Science Foundation of China(21836001)Beijing Outstanding Young Scientist Program are acknowledged.
文摘Biochar have received multidisciplinary attention because of their extraordinary physicochemical properties.In this review,the application of biochar and biochar-based materials for the efficient elimination of organic and inorganic pollutants are summarized.The sorption of organic chemicals and heavy metal ions/radionuclides,degradation/transformation of organic pollutants,and sorption-reduction-solidification of high-valent metal ions are described in detail.The interaction mechanism at molecular level from advanced spectroscopic techniques and theoretical calculations is discussed.Finally,the challenges in the application of biochar and biochar-supported materials in the immobilization of heavy metal ions and photocatalytic degradation of persistent organic pollutants in soils or wastewater are pointed out.This review is helpful for the graduate stu-dents to understand the recent works about biochar and biochar-supported materials in environmental pollutants management.
基金Project supported by the National Natural Science Foundation ofChina (No. 30070017)the Science and Technology Foundationfor Key Project of Zhejiang Province (No. 2003C13005), China
文摘Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dis- solved sulfide (S2- and HS-) in wastewaters and as H2S in waste gases. Due to its corrosive nature, biological hydrogen sulfide removal processes are being investigated to overcome the chemical and disposal costs associated with existing chemically based removal processes. The nitrogen and sulfur metabolism interacts at various levels of the wastewater treatment process. Hence, the sulfur cycle offers possibilities to integrate nitrogen removal in the treatment process, which needs to be further optimized by appropriate design of the reactor configuration, optimization of performance parameters, retention of biomass and optimization of biomass growth. The present paper reviews the biotechnological advances to remove sulfides from various environments.
基金the Project of Netherlands Organization for Cooperation in Higher Education(NUFFIC)/The Netherlands Initiative for Capacity development in Higher Education(NICHE)/Vietnam 105(VNM 105)Supporting the integration in Agricultural Curricula of Climate Change concerns at Universities of Agriculture:Hanoi University of Agriculture,Hong Duc University and Hue University of Agriculture and Forestry(ACCCU)-Wageningen University and the Asian Institute of Technology,Thailand,for funding the work
文摘Application of silicon(Si) could greatly boost rice yield and mitigate abiotic stress,especially drought.A field experiment was conducted during 2015 at the research farm of Hong Duc University,Thanh Hoa City,Vietnam,to evaluate the effects of five different combined doses of standard fertilizer practice and Si fertilizer on growth,yield and yield components,as well as nutrient uptake of rice.The treatments consisted of the recommended dose of fertilizer(RDF,110 kg/hm^2 N + 90 kg/hm^2 P_2O_5 + 80 kg/hm^2 K_2O) as the control,RDF + 100 kg/hm^2 SiO_2,RDF + 200 kg/hm^2 SiO_2,RDF + 300 kg/hm^2 SiO_2 and RDF + 400 kg/hm^2 SiO_2.The results showed that the growth,grain and straw yields as well as yield components(number of grains per panicle,seed-setting rate and 1000-grain weight) were significantly affected by Si application.The highest grain yield of 3 705 kg/hm^2 was obtained with the highest level of Si fertilizer in combination with RDF(RDF + 400 kg/hm^2 SiO_2),however,it was statistically at par with the yields obtained with RDF + 300 kg/hm^2 SiO_2(3 664 kg/hm^2) and RDF + 200 kg/hm^2 SiO_2(3 621 kg/hm^2).The optimum dose of Si fertilizer with maximized grain yield(3 716 kg/hm^2) was 329 kg/hm^2 SiO_2.The nutrient(Si,N,P and K) uptakes of rice were also significantly enhanced by Si application.Si application at the level of 329 kg/hm^2 along with RDF would help in the sustainable production of rice in the tropical zone of Vietnam.
文摘Seeds of Indian mustard （Brassicajuncea （L.） Czern. et Coss.） were exposed to 0, 50, 100 and 150 mmol/L NaCI for 8 h and seeds were sown in an earthen pot. These stressed seedlings were subsequently sprayed with 10μmol/L salicylic acid （SA） at 30 d and were sampled at 60 d to assess the changes in growth, photosynthesis and antioxidant enzymes. The seedlings raised from the seeds treated with NaCI had significantly reduced growth and the activities of carbonic anhydrase, nitrate reductase and photosynthesis, and the decrease was proportional to the increase in NaCI concentration. However, the antioxidant enzymes （catalase, peroxidase and superoxide dismutase） and proline content was enhanced in response to NaCI and/or SA treatment, where their interaction had an additive effect. Moreover, the toxic effects generated by the lower concentration of NaCI （50 mmol/L） were completely overcome by the application of SA. It was, therefore, concluded that SA ameliorated the stress generated by NaCl through the alleviated antioxidant system.
基金supported by the National Natural Science Foundation of China (21225730,91326202,and 21577032)the Fundamental Research Funds for the Central Universities (JB2015001)Furong Scholarship of Hunan Province
文摘With the fast development of nanoscience and nanotechnology,the nanomaterials have attracted multidisciplinary interests.The high specific surface area and large numbers of oxygen-containing functional groups of graphene oxides(GOs) make them suitable in the preconcentration and solidification of radionuclides from wastewater.In this paper,mainly based on the recent work carried out in our laboratory,the efficient elimination of radionuclides using GOs and GO-based nanomaterials as adsorbents are summarized and the interaction mechanisms are discussed from the results of batch techniques,surface complexation modeling,spectroscopic analysis and theoretical calculations.This review is helpful for the understanding of the interactions of radionuclides with GOs and GO-based nanomaterials,which is also crucial for the application of GOs and GO-based nanomaterials in environmental radionuclide pollution management and also helpful in nuclear waste management.
基金supported by research grants to SL from NIH(1R21NS066114,1R01NS079432 and 1R01EY024575)Christopher&Dana Reeve Foundation(LA1-1002-2)Shriners Research Foundation(86300)
文摘The intrinsic growth ability of all the neurons declines during development although some may grow better than others. Numerous intracellular signaling proteins and transcription factors have been shown to regulate the intrinsic growth capacity in mature neurons. Among them, PI3 kinase/Akt pathway is important for controlling axon elongation. As a negative regulator of this pathway, the tumor suppressor phosphatase and tensin homolog （PTEN） appears critical to con- trol the regenerative ability of young and adult neurons. This review will focus on recent research progress in axon regeneration and neural repair by PTEN inhibition and therapeutic potential of blocking this phosphatase for neurological disorders. Inhibition of PTEN by deletion in con- ditional knockout mice, knockdown by short-hairpin RNA, or blockade by pharmacological approaches, including administration of selective PTEN antagonist peptides, stimulates various degrees of axon regrowth in juvenile or adult rodents with central nervous system injuries. Im- portantly, post-injury PTEN suppression could enhance axonal growth and functional recovery in adult central nervous system after injury.
文摘Grade A （GA） and high strength steel DH36 ship steels possessing different chemical compositions were used, and strength properties of GA steel and DH36 steel were compared. Additionally, 4 types of dual phase （DP） steels with different martensite volume fractions （MVFs） were produced from GA steel by means of heat treatment and they were compared with other steels through conducting mierostructure, microhardness, tensile and impact tests. The fracture surfaces of specimens （DH36, GA and DP steels） exposed to tensile and Charpy impact tests were investigated by scanning electron microscope. Furthermore, it was found that the specimens quenched from 800 and 900℃ had better strength than DH36 steel. The tensile test results indicated that the tensile strength of DP steel water quenched from 900℃ was 3 times that of GA steel and twice that of DH36 steel.
基金supported by the National Natural Science Foundation of China(91326202,21577032)the Fundamental Research Funds for the Central Universities(JB2015001,JB2017057)the Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection and the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘An extremely effortless method was applied for successful synthesis of mesoporous carbonaceous materials(MCMs) using well-ordered mesoporous silica as template. Various characterizations(scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), Raman, X-ray photoelectron spectroscopy(XPS), Brunner-Emmet-Teller(BET) and Zeta potential) confirmed that MCMs had large surface area, uniform pore size distribution, and abundant oxygen-containing functional groups. The batch techniques were employed to study U(VI) adsorption on MCMs under a wide range of experiment conditions. The adsorption kinetics of U(VI) onto MCMs were well-fitted by pseudo-second-order kinetic model, indicating a chemisorption process. The excellent adsorption capacity of MCMs calculated from the Langmuir model was 293.95 mg g^(-1) at pH 4.0. The FT-IR and XPS analyses further evidenced that the binding of U(VI) onto MCMs was ascribed to the plentiful adsorption sites(–OH and –COOH groups) in the internal mesoporous structure, which could efficiently trap guest U(VI) ions. The results presented herein revealed that MCMs were ideal adsorbents in the efficient elimination of uranium or other lanthanides/actinides from aqueous solutions, which would play an important role in environmental pollution management application.
基金the financial supports from the Key Research and Development Program of Shanxi Province,China(Nos.201903D421084,201903D121056)the National Natural Science Foundation of China(Nos.52171122,52071228,51901151)。
文摘The effects of sub-transus(α+β)annealing treatment(ST),followed by single aging(SA)or duplex aging(DA)on the microstructural evolution and mechanical properties of near-βTi-4Al-1Sn-2Zr-5Mo-8V-2.5Cr(mass fraction,%)alloy were investigated using optical microscopy,scanning electron microscopy,and transmission electron microscopy.The results show that the finer secondaryαphase precipitates in the alloy after DA than SA(e.g.,149 nm for SA and 69 nm for DA,both after ST at 720℃).The main reason is that the pre-aging step(300℃)in the DA process leads to the formation of intermediateωphase nanoparticles,which assist in the nucleation of the acicular secondaryαphase precipitates.In addition,the strength of the alloy after DA is higher than that of SA at the specific ST temperature.A good combination is achieved in the alloy subjected to ST at 750℃,followed by DA(UTS:1450 MPa,EL:3.87%),which is due to the precipitation of nanoscale secondaryαphase by DA.In conclusion,DA is a feasible process for this new near-βtitanium alloy.
文摘Zinc coated dual phase 600 steel （DP 600 grade） was investigated, utilisation of which has gradually increased with each passing day in the automotive industry. The adhesive bonding （AB）, resistance spot welding （RSW）, and adhesive weld bonding （AWB） ioints of the zinc coated DP 600 steel were investigated. Additionally, the zinc coating was removed using HCL acid in order to investigate the effect of the coating. The microstructure, tensile shear strengths, and fracture properties of adhesive bonding （AB）, resistance spot welding （RSW）, and adhesive weld bonding （AWB） joints of the coated and uncoated DP 600 steel were compared. In addition, a mechani cal-electrical-thermal coupled model in a finite element analysis environment was utilised. The thermal profile phe nomenon was calculated by simulating this process. The results of the tensile shear test indicated that the tensile load bearing capacity （TLBC） values of the coated specimens among the three welding methods were higher than those of the uncoated specimens. Additionally, the tensile strength of the AWB joints of the coated and uncoated specimens was higher than that of the AB and RSW joints. It was determined that the fracture behaviours and the deformation caused were different for the three welding methods.
文摘AIM: To assess and compare the esophageal function after peroral endoscopic myotomy(POEM) vs other conventional treatments in achalasia.METHODS: Chart review of all achalasia patients who underwent POEM, laparoscopic Heller myotomy(LHM) or pneumatic dilation(PD) at our institution between January 2012 and March 2015 was performed. Patient demographics, type of achalasia, prior treatments, pre- and post-treatment timed barium swallow(TBE) and high-resolution esophageal manometry(HREM) findings were compared between the three treatment groups. Patients who had both pre- and 2 mo posttreatment TBE or HREM were included in the final analysis. TBE parameters compared were barium column height, width and volume of barium remaining at 1 and 5 min. HREM parameters compared were basal lower esophageal sphincter(LES) pressures and LES-integrated relaxation pressures(IRP). Data are presented as mean ± SD, median [25th, 75 th percentiles] or frequency(percent). Analysis of variance, KruskalWallis test, Pearsons χ~2 test and Fishers Exact tests were used for analysis.RESULTS: A total of 200 achalasia patients were included of which 36 underwent POEM, 22 underwent PD and 142 underwent LHM. POEM patients were older(55.4 ± 16.8 years vs 46.5 ± 15.7 years, P = 0.013) and had higher BMI than LHM(29.1 ± 5.9 kg/m^2 vs 26 ± 5.1 kg/m^2, P = 0.012). More number of patients in POEM and PD groups had undergone prior treatments compared to LHM group(72.2% vs 68.2% vs 44.3% respectively, P = 0.003). At 2 mo post-treatment, all TBE parameters including barium column height, width and volume remaining at 1 and 5 min improved significantly in all three treatment groups(P = 0.01 to P < 0.001) except the column height at 1 min in PD group(P = 0.11). At 2 mo post-treatment, there was significant improvement in basal LES pressure and LES-IRP in both LHM(40.5 mm Hg vs 14.5 mm Hg and 24 mm Hg vs 7.1 mm Hg respectively, P < 0.001) and POEM groups(38.7 mm Hg vs 11.4 mm Hg and 23.6 mm Hg vs 6.6 mm Hg respectively, P < 0.001). However, when the e
基金This work was supported by the National Key Research and Development Program of China(No.2016YFD-0800807)the National Nature Science Foundation of China(Nos.31702003 and 31902105)+3 种基金the Young Elite Scientists Sponsorship Program of China Association for Science and Technology(CAST)(No.2017QNRC001)the China Postdoctoral Science Foundation(No.2019 M651505)the“Chenguang Program”of the Shanghai Education Development Foundation and Shanghai Municipal Education Commission,China(No.17CG07)the Shanghai Agriculture Science and Technology Development Project,China(No.2018-4-13).
文摘Trace metals such as manganese(Mn),copper(Cu),zinc(Zn),and iron(Fe)are essential for many biological processes in plant life cycles.However,in excess,they can be toxic and disrupt plant growth processes,which is economically undesirable for crop production.For this reason,processes such as homeostasis and transport control of these trace metals are of constant interest to scientists studying heavily contaminated habitats.Phytoremediation is a promising cleanup technology for soils polluted with heavy metals.However,this technique has some disadvantages,such as the slow growth rate of metal-accumulating plant species,low bioavailability of heavy metals,and long duration of remediation.Microbial-assisted phytoremediation is a promising strategy for hyperaccumulating,detoxifying,or remediating soil contaminants.Arbuscular mycorrhizal fungi(AMF)are found in association with almost all plants,contributing to their healthy performance and providing resistance against environmental stresses.They colonize plant roots and extend their hyphae to the rhizosphere region,assisting in mineral nutrient uptake and regulation of heavy metal acquisition.Endophytic fungi exist in every healthy plant tissue and provide enormous services to their host plants,including growth enhancement by nutrient acquisition,detoxification of heavy metals,secondary metabolite regulation,and enhancement of abiotic/biotic stress tolerance.The aim of the present work is to review the recent literature regarding the role of AMF and endophytic fungi in plant heavy metal tolerance in terms of its regulation in highly contaminated conditions.
文摘Introduction: The impact of pregnancy on the prognosis of papillary thyroid carcinoma (PTC) has been debated for several decades;however, no definitive conclusions have been reached. The main objective of this study is to demonstrate the short-term influence of pregnancy on the evolution and prognosis of PTC. Materials and Methods: A prospective descriptive and analytical study was conducted in the Endocrinology and Diabetology Department at the Hassan II University Hospital in Fez, including patients followed for papillary thyroid carcinoma presenting with a pregnancy during the year 2019 and 2020. The follow-up of these patients was continued until 1 year postpartum. We studied the clinical, paraclinical and therapeutic factors that could influence the prognosis of the disease. Results: We included 26 patients. Our study showed a significant correlation between recurrence and the presence of unfavorable histological signs (p = 0.02) as well as the initial Tg level (0.01). However, pregnancy was not an influencing factor (p = 0.41). Conclusion: Pregnancy does not seem to be a factor aggravating the prognosis of differentiated thyroid cancers.
文摘Background: Menopause is a period where natural cessation of menses occurs, some quality of life characteristics changes with some symptoms associated with this time such as hot flushes and anxiety. Objective: To evaluate and specify the level of impact of these symptoms on the quality of life among women in the Qatif area, Saudi Arabia and to study the factors that may involve in their perception. Methods: A cross-sectional study was conducted of 151 women aged 40 - 60 years old interviewed at either hospital or PHCs, a translated and revised questionnaire of other studies with some adoption. Results: 151 women out of 200 participated in questionnaires, majority of them were highly educated having at least a bachelor’s degree around 80%, and around 75% of participants were either working or retired, with a moderate level of income and enjoying a good lifestyle 93% in around and 97% in the after menopause. With the majority, were not used hormones 95% or conceptive pills 91%, personal perception of health were high around 93% for around and 97.2% for after menopause with no significant statistical difference between the two groups. Conclusion: Perception and knowledge of menopause were very high, with no differences in the severity of symptoms of the four QOL domains for the around or after menopause among the participants. High level of education and increased level of income and knowledge of the participants may play an important role in the result, so further investigation is advised.
