Four fat and elongated(F&E)contents(0%,original,30%,and 40%)were investigated to evaluate the effects of F&Eparticles on the performance of porous asphalt mixture(P A).Laboratory tests including volumetric det...Four fat and elongated(F&E)contents(0%,original,30%,and 40%)were investigated to evaluate the effects of F&Eparticles on the performance of porous asphalt mixture(P A).Laboratory tests including volumetric determination,two-dimensional image analysis,Cantabro loss tests,breakdown tests,and permeability tests were conducted to evaluate the volumetric properties,the state of stone-onstone contact,durability,skeleton stability and permeability of PA,respectively.The test results indicate that the F&E content was a significant factor for total air voids,aggregate skeleton break down,and permeability.The functionality,rutting resistance,long-term durability,and skeleton stability decrease with the increase of F&E content since F&E aggregates in porous asphalt mixtures have a tendency to breakdown.Compared with traditional dense graded mixtures,PA is more sensitive to the F&E content due to an open graded aggregate structure.Therefore,the stricter requiement for F&E content should be met for porous asphalt mixtures than the one for traditional deese graded mixture.展开更多
Low bone mineral density and the increased risk of fracture in gastrointestinal diseases have a multifactorial pathogenesis. Inflammatory bowel disease (IBD) has been associated with an increased risk of osteoporosi...Low bone mineral density and the increased risk of fracture in gastrointestinal diseases have a multifactorial pathogenesis. Inflammatory bowel disease (IBD) has been associated with an increased risk of osteoporosis and osteopenia and epidemiologic studies have reported an increased prevalence of low bone mass in patients with IBD. Certainly, genetics play an important role, along with other factors such as systemic inflammation, malnutrition, hypogonadism, glucocorticoid therapy in IBD and other lifestyle factors. At a molecular level the proinflammatory cytokines that contribute to the intestinal immune response in IBD are known to enhance bone resorption. There are genes influencing osteoblast function and it is likely that LRP5 may be involved in the skeletal development. Also the identification of vitamin D receptors (VDRs) and some of its polymorphisms have led to consider the possible relationships between them and some autoimmune diseases and may be involved in the pathogenesis through the exertion of its immunomodulatory effects during inflammation. Trying to explain the physiopathology we have found that there is increasing evidence for the integration between systemic inflammation and bone loss likely mediated via receptor for activated nuclear factor kappa-B (RANK), RANK-ligand, and osteoprotegerin, proteins that can affect both osteoclastogenesis and T-cell activation. Although glucocorticoids can reduce mucosal and systemic inflammation, they have intrinsic qualities that negatively impact on bone mass. It is still controversial if all IBD patients should be screened, especially in patients with preexisting risk factors for bone disease. Available methods to measure BMD include single energy x-ray absorptiometry, DXA, quantitative computed tomography (QCT), radiographic absorptiometry, and ultrasound.DXA is the establish method to determine BMD, and routinely is measured in the hip and the lumbar spine. There are several treatments options that have proven their effectiveness, while new emergent therapies such as calcitonin and teriparatide among others remain to be assessed.展开更多
Objective To retrospectively assess the primary clinical results of a cohort of the first metatarsophalangeal joint replacement with double-stemmed hinge silicone implant. Methods A total of 12 patients (15 feet) rec...Objective To retrospectively assess the primary clinical results of a cohort of the first metatarsophalangeal joint replacement with double-stemmed hinge silicone implant. Methods A total of 12 patients (15 feet) received the joint replacement with double-stemmed hinge silicone implant. There were 2 males and l0 females with a mean age of 61.4 (range, 56-75) years old. Of them, 9 cases (11 feet) were hallux valgus with osteoarthritis; 1 case (2 feet) was rheumatic arthritis; 2 cases (2 feet) were traumatic arthritis. The sub)ective and objective results were evaluated during follow-up. Results All of the patients were followed up regularly with an average of 24.7 months, ranging from 12 to 38 months. Ten patients were completely satisfied with the operation; I patient showed partial saris- faction, and 1 patient was not satisfied because of the first matatarsophalangeal joint pain due to severe hy- perosteogeny surrounding the cut bone surface 3 years after the operation. Osteolysis around the implant occurred in 2 cases without clinical symptoms, and no special treatment was given. Conclusion The joint replacement is a preferable method in alleviating pain and improving walking function with proper indication.展开更多
To study the behavior and design of tubed circular steel reinforced concrete (TCSRC) short column under axial compressive loads, a nonlinear finite element model (FEM) has been developed to simulate this kind of struc...To study the behavior and design of tubed circular steel reinforced concrete (TCSRC) short column under axial compressive loads, a nonlinear finite element model (FEM) has been developed to simulate this kind of structure. Depending on the FEM results, an elastic-plastic analysis was carried out to clarify the status of steel tube, then a simplified procedure was proposed to predict the compressive axial load strength. The results obtained from this procedure were compared with the test results. It is found that they agree well each other.展开更多
We present a case of a 25-year-old female with diagnosed familial adenomatous polyposis and elevated carcinoembryonic antigen with negative family history. The suspicion of Gardner's syndrome was raised because ex...We present a case of a 25-year-old female with diagnosed familial adenomatous polyposis and elevated carcinoembryonic antigen with negative family history. The suspicion of Gardner's syndrome was raised because extirpation of an osteoma of the left temporo-occipital region was made 10 years ago. Restorative procto-colectomy and ileal pouch anal anastomosis was made but histology delineated adenocarcinoma of the rectum (Dukes C stage). We conclude that cranial osteomas often precede gastrointestinal manifestations of familial adenomatous polyposis or Gardner's syndrome and such patients should be evaluated with genetic testing followed by colonoscopy if results are positive to prevent the development of colorectal carcinoma. If the diagnosis is positive all family members should be evaluated for familial adenomatous polyposis.展开更多
Objective: To investigate the effects of soluble factors secreted by acute myeloid leukemia (AML) cells on the phenotypical and functional properties of DCs derived from normal mononuclear cells. Methods: Mononucl...Objective: To investigate the effects of soluble factors secreted by acute myeloid leukemia (AML) cells on the phenotypical and functional properties of DCs derived from normal mononuclear cells. Methods: Mononuclear cells were cultured with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF), in the presence or absence of 24 h culture supematants from fresh pdmary AML cells, to generate immature DCs. The maturation of DCs was induced by cytokines IL-lbeta, IL-6, tumor necrosis factor-alpha (TNF-alpha), and prostaglandin-2 (PGE-2). The phenotypic alterations of DCs and DCs-primed CD4+ T cells were evaluated using flow cytometry. Precursor frequency (PF) was calculated to monitor the allostimulatory effects of DCs on CD4^+ and CD8^+ T cells. Results:AML cell supernatant-treated DCs showed significantly lower expression of co-stimulatory molecules CDS0 and CD86, and reduced response to cytokines IL-1beta, IL-6, TNF-alpha, and PGE-2. The allostimulatory effects of AML cell supematant-treated DCs on CD4^+ and CD8^+ T cells were significantly lower than those of normal mature DCs [PF: (1.8 ±0.5)% vs. (5.2 ± 1.6)% for CD4^+ T cells, (2.1 ±0.6)% vs. (6.5 ± 2.0)% for CD8^+ T cells, P 〈 0.01]. These AML supernatantoinduced DCs could also induce allogeneic CD4^+ T cells to differentiate into CD4^+CD25high T cells, which had immunophenotyping characteristics of regulatory T cells, i.e. they expressed Foxp3 but not active maker CD69. Conclusion: This study demonstrates that soluble factors secreted by AML cells can inhibit development and functions of DCs. In addition, AML supernatant-induced DCs can induce the generation of CD4^+CD25^high T cells from CD4^+ T cells, which may be a mechanism of increased prevalence of CD4^+CD25^high regulatory T cells and immune dysfunction in AML patients.展开更多
Objective.To investigate the distribution frequency of parathyroid hormone(PTH)gene polymorphism in healthy adults from Bejing area and to explore the association of PTH genotypes with bone mineral density(BMD).Method...Objective.To investigate the distribution frequency of parathyroid hormone(PTH)gene polymorphism in healthy adults from Bejing area and to explore the association of PTH genotypes with bone mineral density(BMD).Methods.PTH gene polymorphism was detected in270subjects by polymerase chain reaction(PCR)and PCR /restriction fragment length polymorphism(PCR /RFLP).The digestion products of restriction enzyme Bst B1were separated on1%agarose gels.PTH genotypes were confirmed by DNA sequences analysis.BMD was measured by dual-energy X-ray absorptiometry(DEXA,DPX -L ,Lunar).Results.Genotype frequencies of BB,Bb,bb were73.7%,25.9%and0.4%respectively in Beijing adults(P<0.01),67.1%,32.2%and0.7%in postmenopausal women,which was different from Japanese wom-en.We statistically compared bone mineral density at the lumbar2-4and proximal femur between BB and Bb genotypes.No obvious association was found between the BMD and PTH genotypes in Beijing women(P>0.05).Conclusion.PTH gene polymorphism is not associated with BMD in Chinese women.The further research to explore the genetic risk factors of osteoporosis should be committed.展开更多
OBJECTIVE To study the mechanism of IFN on CML.METHODS Samples of 15 CML patients and 10 healthy controlswere studied. The flow cytometry was performed to identifycirculating pDCs. The concentration of IFN-α in serum...OBJECTIVE To study the mechanism of IFN on CML.METHODS Samples of 15 CML patients and 10 healthy controlswere studied. The flow cytometry was performed to identifycirculating pDCs. The concentration of IFN-α in serum and that inthe supernatant of peripheral blood mononuclear cells (PBMCs)cultured after stimulation with CpG ODN2216 were examinedboth in CML patients and in the healthy controlsRESULTS There was significant reduction in the numberof circulating pDCs, serum concentration of IFN-α and thecapacity of IFN-α producing PBMCs in CML patients comparedwith those in healthy control individuals (P < 0.001). After theactive treatment with IFN-α and hydroxyurea, the quantity andfunction of pDCs were increased in stabilized patients, especiallythe function of pDCs in 2 patients achieving major cytogeneticresponse (MCR). The proportion and function of pDCs and theserum levels of IFN were inversely correlated with both WBC andage of the patients with CML, and positively correlated with thestate of the illness.CONCLUSION CML patients had a reduced number anddysfunction of circulating pDCs. The active treatment with IFN inCML patients may be related to the restoration of pDCs.展开更多
Objective: To observe the curative effect of dissolving phlegm-stasis on knee osteoarthritis. Methods: The 100 patients with knee osteoarthritis were randomly divided into two groups. The 50 patients in the treatmen...Objective: To observe the curative effect of dissolving phlegm-stasis on knee osteoarthritis. Methods: The 100 patients with knee osteoarthritis were randomly divided into two groups. The 50 patients in the treatment group orally took Chinese medicine while the other 50 patients in the control groups orally took Votalin and Vitamin C for one week as a course of treatment. At the end of 2-week treatment, analytic comparison was carried in evaluate the curative effect and the changes in total score of symptoms before and after treatment between the two groups. Results: The total score of symptoms after treatment was significantly lower than that before treatment in both groups (P〈0.01, P〈0.05). The total score after treatment of patients with X-ray grade I and II in the treatment group was more obviously reduced as compared to the control group (P〈0.05). The remarkably effective rate after treatment of patients with X-ray grade I and It in the treatment group was also higher than that in the control group (P〈0.05). Conclusion: The treatment of knee osteoarthritis with dissolving phlegm-stasis can effectively improve the clinical symptoms.展开更多
In contrast to open degloving injury, extensive closed internal degloving injury (CIDI) is rare, especialy followed by deep injury with bone-articular and neurovascular complications after initial trauma.1-3 Clinicall...In contrast to open degloving injury, extensive closed internal degloving injury (CIDI) is rare, especialy followed by deep injury with bone-articular and neurovascular complications after initial trauma.1-3 Clinically, it 05- be misdiagnosed or mismanaged leading to delayed full-thickness necrosis of the avulsed skin flap and development of wound sepsis, 3 even limbs disability.4 A number of reports have advocated several means for treatment of CIDI1,3,5,6 but they are not ideal.1,6,7 Since 1987 we have treated 132 degloving injuries, 18 (13.6%) of whom were CIDI in the peripelvis and lower limbs. According to the severity of CIDI, it has been managed by replantation of defatted full-thickness degloved skin with refined techniques as salvage procedures for the avulsed skin, and defect coverage with several myocutaneous flaps for denuded wound of specialized areas. Our purpose is to stress the importance of simultaneous management of both CIDI and deep injury and proper options of resurface procedures to provide better appearance and function of limbs.展开更多
Precise control of the size and morphology of metal-organic frameworks(MOFs) presents an important direction for extending these inorganic-organic materials to many more advanced applications. However, because of the ...Precise control of the size and morphology of metal-organic frameworks(MOFs) presents an important direction for extending these inorganic-organic materials to many more advanced applications. However, because of the limit of the crystal-growth rule and mechanism, good-control of the size and morphology of MOFs remains challenging. In this contribution, an iron-terephthalic acid metal-organic framework with different shapes(octahedron, spindle and bipyramidal hexagonal) was easily and reproducibly synthesized via a solvothermal method. Sodium acetate and glycerol were used as modulators. Mechanism studies showed that the crystal nucleation rate and orientational growth both play important roles in determining the final shape of the MOFs. Further investigations showed that the as prepared MOFs exhibit shape-dependent catalytic activities, which means that MOFs can be designed to perform different catalytic functions. This investigation not only provides an effective guideline for the precise control of the size and morphology of metal-organic frameworks, but also extends MOFs to much more advanced applications in terms of catalyst chemistry.展开更多
基金Transportation Science and Technology Project of Jiangsu Province(No.7621000115)Science and Technology Project of Nanjing Committee of Housing and Urban-Rural Development(No.ks1611)
文摘Four fat and elongated(F&E)contents(0%,original,30%,and 40%)were investigated to evaluate the effects of F&Eparticles on the performance of porous asphalt mixture(P A).Laboratory tests including volumetric determination,two-dimensional image analysis,Cantabro loss tests,breakdown tests,and permeability tests were conducted to evaluate the volumetric properties,the state of stone-onstone contact,durability,skeleton stability and permeability of PA,respectively.The test results indicate that the F&E content was a significant factor for total air voids,aggregate skeleton break down,and permeability.The functionality,rutting resistance,long-term durability,and skeleton stability decrease with the increase of F&E content since F&E aggregates in porous asphalt mixtures have a tendency to breakdown.Compared with traditional dense graded mixtures,PA is more sensitive to the F&E content due to an open graded aggregate structure.Therefore,the stricter requiement for F&E content should be met for porous asphalt mixtures than the one for traditional deese graded mixture.
文摘Low bone mineral density and the increased risk of fracture in gastrointestinal diseases have a multifactorial pathogenesis. Inflammatory bowel disease (IBD) has been associated with an increased risk of osteoporosis and osteopenia and epidemiologic studies have reported an increased prevalence of low bone mass in patients with IBD. Certainly, genetics play an important role, along with other factors such as systemic inflammation, malnutrition, hypogonadism, glucocorticoid therapy in IBD and other lifestyle factors. At a molecular level the proinflammatory cytokines that contribute to the intestinal immune response in IBD are known to enhance bone resorption. There are genes influencing osteoblast function and it is likely that LRP5 may be involved in the skeletal development. Also the identification of vitamin D receptors (VDRs) and some of its polymorphisms have led to consider the possible relationships between them and some autoimmune diseases and may be involved in the pathogenesis through the exertion of its immunomodulatory effects during inflammation. Trying to explain the physiopathology we have found that there is increasing evidence for the integration between systemic inflammation and bone loss likely mediated via receptor for activated nuclear factor kappa-B (RANK), RANK-ligand, and osteoprotegerin, proteins that can affect both osteoclastogenesis and T-cell activation. Although glucocorticoids can reduce mucosal and systemic inflammation, they have intrinsic qualities that negatively impact on bone mass. It is still controversial if all IBD patients should be screened, especially in patients with preexisting risk factors for bone disease. Available methods to measure BMD include single energy x-ray absorptiometry, DXA, quantitative computed tomography (QCT), radiographic absorptiometry, and ultrasound.DXA is the establish method to determine BMD, and routinely is measured in the hip and the lumbar spine. There are several treatments options that have proven their effectiveness, while new emergent therapies such as calcitonin and teriparatide among others remain to be assessed.
文摘Objective To retrospectively assess the primary clinical results of a cohort of the first metatarsophalangeal joint replacement with double-stemmed hinge silicone implant. Methods A total of 12 patients (15 feet) received the joint replacement with double-stemmed hinge silicone implant. There were 2 males and l0 females with a mean age of 61.4 (range, 56-75) years old. Of them, 9 cases (11 feet) were hallux valgus with osteoarthritis; 1 case (2 feet) was rheumatic arthritis; 2 cases (2 feet) were traumatic arthritis. The sub)ective and objective results were evaluated during follow-up. Results All of the patients were followed up regularly with an average of 24.7 months, ranging from 12 to 38 months. Ten patients were completely satisfied with the operation; I patient showed partial saris- faction, and 1 patient was not satisfied because of the first matatarsophalangeal joint pain due to severe hy- perosteogeny surrounding the cut bone surface 3 years after the operation. Osteolysis around the implant occurred in 2 cases without clinical symptoms, and no special treatment was given. Conclusion The joint replacement is a preferable method in alleviating pain and improving walking function with proper indication.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50708027)National Key Technology R&D Program of China(Grant No.2006BAJ01B02)
文摘To study the behavior and design of tubed circular steel reinforced concrete (TCSRC) short column under axial compressive loads, a nonlinear finite element model (FEM) has been developed to simulate this kind of structure. Depending on the FEM results, an elastic-plastic analysis was carried out to clarify the status of steel tube, then a simplified procedure was proposed to predict the compressive axial load strength. The results obtained from this procedure were compared with the test results. It is found that they agree well each other.
文摘We present a case of a 25-year-old female with diagnosed familial adenomatous polyposis and elevated carcinoembryonic antigen with negative family history. The suspicion of Gardner's syndrome was raised because extirpation of an osteoma of the left temporo-occipital region was made 10 years ago. Restorative procto-colectomy and ileal pouch anal anastomosis was made but histology delineated adenocarcinoma of the rectum (Dukes C stage). We conclude that cranial osteomas often precede gastrointestinal manifestations of familial adenomatous polyposis or Gardner's syndrome and such patients should be evaluated with genetic testing followed by colonoscopy if results are positive to prevent the development of colorectal carcinoma. If the diagnosis is positive all family members should be evaluated for familial adenomatous polyposis.
基金grants from the National Outstanding Young Investigator Program (30225038)Anhui Provincial Natural Science Foundation (070413094)+1 种基金Scientific Research Fund of Anhui Provincial Education Department (2006KJ072C)Science and Technological Fund of Anhui Province for Outstanding Youth.
文摘Objective: To investigate the effects of soluble factors secreted by acute myeloid leukemia (AML) cells on the phenotypical and functional properties of DCs derived from normal mononuclear cells. Methods: Mononuclear cells were cultured with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF), in the presence or absence of 24 h culture supematants from fresh pdmary AML cells, to generate immature DCs. The maturation of DCs was induced by cytokines IL-lbeta, IL-6, tumor necrosis factor-alpha (TNF-alpha), and prostaglandin-2 (PGE-2). The phenotypic alterations of DCs and DCs-primed CD4+ T cells were evaluated using flow cytometry. Precursor frequency (PF) was calculated to monitor the allostimulatory effects of DCs on CD4^+ and CD8^+ T cells. Results:AML cell supernatant-treated DCs showed significantly lower expression of co-stimulatory molecules CDS0 and CD86, and reduced response to cytokines IL-1beta, IL-6, TNF-alpha, and PGE-2. The allostimulatory effects of AML cell supematant-treated DCs on CD4^+ and CD8^+ T cells were significantly lower than those of normal mature DCs [PF: (1.8 ±0.5)% vs. (5.2 ± 1.6)% for CD4^+ T cells, (2.1 ±0.6)% vs. (6.5 ± 2.0)% for CD8^+ T cells, P 〈 0.01]. These AML supernatantoinduced DCs could also induce allogeneic CD4^+ T cells to differentiate into CD4^+CD25high T cells, which had immunophenotyping characteristics of regulatory T cells, i.e. they expressed Foxp3 but not active maker CD69. Conclusion: This study demonstrates that soluble factors secreted by AML cells can inhibit development and functions of DCs. In addition, AML supernatant-induced DCs can induce the generation of CD4^+CD25^high T cells from CD4^+ T cells, which may be a mechanism of increased prevalence of CD4^+CD25^high regulatory T cells and immune dysfunction in AML patients.
文摘Objective.To investigate the distribution frequency of parathyroid hormone(PTH)gene polymorphism in healthy adults from Bejing area and to explore the association of PTH genotypes with bone mineral density(BMD).Methods.PTH gene polymorphism was detected in270subjects by polymerase chain reaction(PCR)and PCR /restriction fragment length polymorphism(PCR /RFLP).The digestion products of restriction enzyme Bst B1were separated on1%agarose gels.PTH genotypes were confirmed by DNA sequences analysis.BMD was measured by dual-energy X-ray absorptiometry(DEXA,DPX -L ,Lunar).Results.Genotype frequencies of BB,Bb,bb were73.7%,25.9%and0.4%respectively in Beijing adults(P<0.01),67.1%,32.2%and0.7%in postmenopausal women,which was different from Japanese wom-en.We statistically compared bone mineral density at the lumbar2-4and proximal femur between BB and Bb genotypes.No obvious association was found between the BMD and PTH genotypes in Beijing women(P>0.05).Conclusion.PTH gene polymorphism is not associated with BMD in Chinese women.The further research to explore the genetic risk factors of osteoporosis should be committed.
基金supported by a grant from the Science and Technology Planning Project of Gansu Province,China(No.2005LZ0627).
文摘OBJECTIVE To study the mechanism of IFN on CML.METHODS Samples of 15 CML patients and 10 healthy controlswere studied. The flow cytometry was performed to identifycirculating pDCs. The concentration of IFN-α in serum and that inthe supernatant of peripheral blood mononuclear cells (PBMCs)cultured after stimulation with CpG ODN2216 were examinedboth in CML patients and in the healthy controlsRESULTS There was significant reduction in the numberof circulating pDCs, serum concentration of IFN-α and thecapacity of IFN-α producing PBMCs in CML patients comparedwith those in healthy control individuals (P < 0.001). After theactive treatment with IFN-α and hydroxyurea, the quantity andfunction of pDCs were increased in stabilized patients, especiallythe function of pDCs in 2 patients achieving major cytogeneticresponse (MCR). The proportion and function of pDCs and theserum levels of IFN were inversely correlated with both WBC andage of the patients with CML, and positively correlated with thestate of the illness.CONCLUSION CML patients had a reduced number anddysfunction of circulating pDCs. The active treatment with IFN inCML patients may be related to the restoration of pDCs.
文摘Objective: To observe the curative effect of dissolving phlegm-stasis on knee osteoarthritis. Methods: The 100 patients with knee osteoarthritis were randomly divided into two groups. The 50 patients in the treatment group orally took Chinese medicine while the other 50 patients in the control groups orally took Votalin and Vitamin C for one week as a course of treatment. At the end of 2-week treatment, analytic comparison was carried in evaluate the curative effect and the changes in total score of symptoms before and after treatment between the two groups. Results: The total score of symptoms after treatment was significantly lower than that before treatment in both groups (P〈0.01, P〈0.05). The total score after treatment of patients with X-ray grade I and II in the treatment group was more obviously reduced as compared to the control group (P〈0.05). The remarkably effective rate after treatment of patients with X-ray grade I and It in the treatment group was also higher than that in the control group (P〈0.05). Conclusion: The treatment of knee osteoarthritis with dissolving phlegm-stasis can effectively improve the clinical symptoms.
文摘In contrast to open degloving injury, extensive closed internal degloving injury (CIDI) is rare, especialy followed by deep injury with bone-articular and neurovascular complications after initial trauma.1-3 Clinically, it 05- be misdiagnosed or mismanaged leading to delayed full-thickness necrosis of the avulsed skin flap and development of wound sepsis, 3 even limbs disability.4 A number of reports have advocated several means for treatment of CIDI1,3,5,6 but they are not ideal.1,6,7 Since 1987 we have treated 132 degloving injuries, 18 (13.6%) of whom were CIDI in the peripelvis and lower limbs. According to the severity of CIDI, it has been managed by replantation of defatted full-thickness degloved skin with refined techniques as salvage procedures for the avulsed skin, and defect coverage with several myocutaneous flaps for denuded wound of specialized areas. Our purpose is to stress the importance of simultaneous management of both CIDI and deep injury and proper options of resurface procedures to provide better appearance and function of limbs.
基金supported by the National Natural Science Foundation of China(21175109)the Chongqing Key Laboratory Special Fund
文摘Precise control of the size and morphology of metal-organic frameworks(MOFs) presents an important direction for extending these inorganic-organic materials to many more advanced applications. However, because of the limit of the crystal-growth rule and mechanism, good-control of the size and morphology of MOFs remains challenging. In this contribution, an iron-terephthalic acid metal-organic framework with different shapes(octahedron, spindle and bipyramidal hexagonal) was easily and reproducibly synthesized via a solvothermal method. Sodium acetate and glycerol were used as modulators. Mechanism studies showed that the crystal nucleation rate and orientational growth both play important roles in determining the final shape of the MOFs. Further investigations showed that the as prepared MOFs exhibit shape-dependent catalytic activities, which means that MOFs can be designed to perform different catalytic functions. This investigation not only provides an effective guideline for the precise control of the size and morphology of metal-organic frameworks, but also extends MOFs to much more advanced applications in terms of catalyst chemistry.