To investigate the stability of rock mass in high geostress underground powerhouse caverns subjected to excavation,a microseismic(MS)monitoring system was established and the discrete element method(DEM)-based numeric...To investigate the stability of rock mass in high geostress underground powerhouse caverns subjected to excavation,a microseismic(MS)monitoring system was established and the discrete element method(DEM)-based numerical simulation was carried out.The tempo-spatial damage characteristics of rock mass were analyzed.The evolution laws of MS source parameters during the formation of a rock collapse controlled by high geostress and geological structure were investigated.Additionally,a three-dimensional DEM model of the underground powerhouse caverns was built to reveal the deformation characteristics of rock mass.The results indicated that the MS events induced by excavation of high geostress underground powerhouse caverns occurred frequently.The large-stake crown of the main powerhouse was the main damage area.Prior to the rock collapse,the MS event count and accumulated energy release increased rapidly,while the apparent stress sharply increased and then decreased.The amount and proportion of shear and mixed MS events remarkably increased.The maximum displacement was generally located near the spandrel areas.The MS monitoring data and numerical simulation were in good agreement,which can provide significant references for damage evaluation and disaster forecasting in high geostress underground powerhouse caverns.展开更多
Rock mass large deformation in underground powerhouse caverns has been a severe hazard in hydropower engineering in Southwest China.During the development of rock mass large deformation,a sequence of fractures was gen...Rock mass large deformation in underground powerhouse caverns has been a severe hazard in hydropower engineering in Southwest China.During the development of rock mass large deformation,a sequence of fractures was generated that can be monitored using microseismic(MS)monitoring techniques.Two MS monitoring systems were established in two typical underground powerhouse caverns featuring distinct geostress levels.The MS b-values associated with rock mass large deformation and their temporal variation are analysed.The results showed that the MS bvalue in course of rock mass deformation was less than 1.0 in the underground powerhouse caverns at a high stress level while larger than 1.5 at a low stress level.Prior to the rock mass deformation,the MS b-values derived from both the high-stress and low-stress underground powerhouse caverns show an incremental decrease over 10%within 10 d.The results contribute to understanding the fracturing characteristics of MS sources associated with rock mass large deformation and provide a reference for early warning of rock mass large deformation in underground powerhouse caverns.展开更多
High-risk human papillomavirus (hrHPV) infection plays an important role in the development of cervical intraepithelial neoplasia and cervical cancer.A total of 11 549 women were enrolled from the Maternal and Child H...High-risk human papillomavirus (hrHPV) infection plays an important role in the development of cervical intraepithelial neoplasia and cervical cancer.A total of 11 549 women were enrolled from the Maternal and Child Health Hospital of Hubei Province.Each participant accepted hrHPV testing and completed a self^administered questionnaire about basic information and potential risk factors.The univariable and multivariable logistic regression model was used to explore the associations between variants and hrHPV infection.Our results showed that hrHPV prevalence was 16.09% in Hubei Province,among which,hrHPV was more likely to be positive in women aged 51 years or above (OR=1.65,95% CI:1.28-2.14),and in women who had symptoms of bleeding after intercourse (OR=1.32,95% CI:1.17-1.50),had first sexual intercourse at the age of 18 years or below (OR=1.33,95% CI:1.07-1.64),had at least three male sexual partners (OR=2.50,95% CI:2.07-3.03),and who had been diagnosed with sexually transmitted infections (OR=1.50,95% CI:1.12-2.03).Married women (OR=0.66,95% CI:0.55-0.78) and women who frequently used condoms (OR=0.75,95% CI:0.67-0.84) had a relatively lower hrHPV prevalence.This study confirms that hrHPV infection was associated with age,marital status,symptoms of intercourse bleeding,history of sexually transmitted infections,and sex-related behaviors.Above all,this study provides a baseline database prior to obtaining vaccinations for dynamic tracking of the changes in hrHPV prevalence.展开更多
Emerging excessive greenhouse gas emissions pose great threats to the ecosystem,which thus requires efficient CO_(2)capture to mitigate the disastrous issue.In this report,large molecular size bisphenol A ethoxylate d...Emerging excessive greenhouse gas emissions pose great threats to the ecosystem,which thus requires efficient CO_(2)capture to mitigate the disastrous issue.In this report,large molecular size bisphenol A ethoxylate diacrylate(BPA)was employed to crosslink poly(ethylene glycol)methyl ether acrylate(PEGMEA)via the green and rapid UV polymerization strategy.The microstructure of such-prepared membrane could be conveniently tailored by tuning the ratio of the two prepolymers,aiming at obtaining the optimized microstructures with suitable mesh size and PEO sol content,which was approved by a novel low-field nuclear magnetic resonance technique.The optimum membrane overcomes the tradeoff challenge:dense microstructures lower the gas permeability while loose microstructures lower high-pressure-resistance capacity,realizing a high CO_(2)permeability of 1711 Barrer and 100-h long-term running stability under 15 atm.The proposed membrane fabrication approach,hence,opens a novel gate for developing high-performance robust membranes for CO_(2)capture.展开更多
Two-dimensional(2D)membrane-based ion separation technology has been increasingly explored to address the problem of lithium resource shortage,yet it remains a sound challenge to design 2D membranes of high selectivit...Two-dimensional(2D)membrane-based ion separation technology has been increasingly explored to address the problem of lithium resource shortage,yet it remains a sound challenge to design 2D membranes of high selectivity and permeability for ion separation applications.Zeolitic imidazolate framework functionalized modified layered double hydroxide(ZIF-8@MLDH)composite membranes with high lithium-ion(Li^(+)) permeability and excellent operational stability were obtained in this work by in situ depositing functional ZIF-8 nanoparticles into the nanopores acting as framework defects in MLDH membranes.The defect-rich framework amplified the permeability of Li^(+),and the site-selective growth of ZIF-8 in the framework defects bettered its selectivity.Specifically speaking,the ZIF-8@MLDH membranes featured a high permeation rate of Li^(+) up to 1.73 mol m^(−2) h^(−1) and a desirable selectiv-ity of Li^(+)/Mg^(2+) up to 31.9.Simulations supported that the simultaneously enhanced selectivity and permeability of Li+are attributed to changes in the type of mass transfer channels and the difference in the dehydration capacity of hydrated metal cations when they pass through nanochannels of ZIF-8.This study will inspire the ongoing research of high-performance 2D membranes through the engineering of defects.展开更多
Background： Renal function is associated with mortality and functional disabilities in stroke patients, and impaired autonomic function is common in stroke, but little is known regarding its effects on stroke patient...Background： Renal function is associated with mortality and functional disabilities in stroke patients, and impaired autonomic function is common in stroke, but little is known regarding its effects on stroke patients with renal dysfunction. This study sought to evaluate the association between autonomic function and stroke in patients with renal dysfunction. Methods： This study comprised 232 patients with acute ischemic stroke consecutively enrolled from February 2013 to November 2014 at Guangdong Provincial Hospital of Chinese Medicine in China. All patients recruited underwent laboratory evaluation and 24 h Holter electrocardiography （ECG）. Autonomic function was measured based on the heart rate variability （HRV） using 24 h Holter ECG. Renal damage was assessed through the estimated glomerular filtration rate （eGFR）, and stroke severity was rated according to the National Institutes of Health Stroke Scale （NIHSS）. The Barthel index and modifed Rankin score were also determined following admission. All the clinical covariates that could potentially affect autonomic outcome variables were adjusted with linear regression. Results： In the patients with a mild or moderate decreased eGFR, the values for the standard deviation of the averaged normal-to-normal RR interval （SDANN） index （P = 0.022L very low frequency （VLF） （P = 0.043）, low frequency （LF） （P= 0.023）, and ratio of low-to-high frequency power （LF/HF） （P = 0.001 ） were significantly lower than those in the patients with a normal eGFR. A lnultinomial linear regression indicated that eGFR （t - 2.47, P - 0.014）, gender （t - -3.60, P 〈0.001）, and a history of hypertension （t = -2.65, P = 0.008） were the risk factors of LF/HF; the NIHSS score （SDANN index： t = -3.83, P 〈 0.001 ; VLF： t = -3.07, P = 0.002： LF： t = -2.79, P = 0.006） and a history of diabetes （SDANN index： t = -3.58, P 〈 0.001; VLF： t = -2.54, P = 0.012; LF： t = -2.87, P = 0.004） were independent factors Ib展开更多
Polyelectrolyte-surfactant complexes（PESCs） were fabricated through the interaction of poly（acrylic acid） and four different cationic surfactants or their mixtures. PESC membranes were prepared by solution casting...Polyelectrolyte-surfactant complexes（PESCs） were fabricated through the interaction of poly（acrylic acid） and four different cationic surfactants or their mixtures. PESC membranes were prepared by solution casting method and were applied in ethanol recovery from aqueous solution via pervaporation. Elemental analysis（EA）, Fourier transform infrared spectroscopy（FTIR）, water contact angle（CA） measurement, differential scanning calorimetry（DSC） and X-ray scattering were employed to characterize the composition, structure and properties of PESCs. The results reveal that the investigated PESCs are similar in hydrophobicity but different in hierarchical nanostructures. In separating 5 wt% ethanol/water mixture, PESC membranes with high crystallinity will have both low flux and ethanol selectivity because of the high packing density and low permeability of crystalline regions. Meanwhile, the hierarchical nanostructures of PESC membranes change under pervaporation environment as was revealed by in situ synchrotron radiation X-ray scattering measurement. That is, the crystalline region could melt at high temperature in swelling state, thus consequently enhancing the ethanol selectivity.展开更多
Polymeric nanomaterials,which have tuneable chemical structures,versatile functionalities,and good compatibility with polymeric matrices,have attracted increasing interest from researchers for the construction of poly...Polymeric nanomaterials,which have tuneable chemical structures,versatile functionalities,and good compatibility with polymeric matrices,have attracted increasing interest from researchers for the construction of polymeric nano-based separation membranes.With their distinctive nanofeatures,polymeric nano-based membranes show great promise in overcoming bottlenecks in polymer membranes,namely,the trade-off between permeability and selectivity,low stability,and fouling issues.Accordingly,recent studies have focused on tuning the structures and tailoring the surface properties of polymeric nano-based membranes via exploitation of membrane fabrication techniques and surface modification strategies,with the objective of pushing the performance of polymeric nano-based membranes to a new level.In this review,first,the approaches for fabricating polymeric nano-based mixed matrix membranes and homogeneous membranes are summarized,such as surface coating,phase inversion,interfacial polymerization,and self-assembly methods.Next,the manipulation strategies of membrane surface properties,namely,the hydrophilicity/hydrophobicity,charge characteristics,and surface roughness,and interior microstructural properties,namely,the pore size and content,channel construction and regulation,are comprehensively discussed.Subsequently,the separation performances of liquid ions/molecules and gas molecules through polymeric nano-based membranes are systematically reported.Finally,we conclude this review with an overview of various unsolved scientific and technical challenges that are associated with new opportunities in the development of advanced polymeric nano-based membranes.展开更多
In this study,the application of bovine serum albumin(BSA)as a carrier to glucose-sensitive materials for the detection of glucose was proposed.Au-Cu O bimetallic nanoclusters(Au-Cu O/BSA)were prepared using BSA as a ...In this study,the application of bovine serum albumin(BSA)as a carrier to glucose-sensitive materials for the detection of glucose was proposed.Au-Cu O bimetallic nanoclusters(Au-Cu O/BSA)were prepared using BSA as a template,the new sensing material(Au-Cu O/BSA/MWCNTs)was synthesized by mixing with multi-walled carbon nanotubes(MWCNT)and applied to non-enzymatic electrochemical sensors to detect glucose stably and effectively under neutral condition.The scanning electron microscopy was used to investigate the morphology of the synthesized nanocomposite.The electrochemical properties of the sensor were studied by cyclic voltammetry.Glucose detection experiments show that Au-Cu O/BSA/MWCNTs/Au electrode has good glucose detection ability,stability,accuracy,repeatability,and high selectivity in neutral environment.Unlike existing glucose-sensitive materials,due to the use of BSA,the composite material is firmly fixed to the electrode surface without a Nafion solution,which reduces the current blocking effect on the modified electrode.The composite materials can be effectively preserved for extremely long periods,higher than 80%activity is maintained at room temperature in a closed environment for 3 to 4 months,due to the special effects of BSA.In addition,the feasibility of using BSA in glucose-sensitive materials is confirmed.展开更多
Objective To develop a specific SARS virus-targeted antibody preparation for emergent prophylaxis and treatment of SARS virus infection. Methods By using phage display technology, we constructed a naive antibody libra...Objective To develop a specific SARS virus-targeted antibody preparation for emergent prophylaxis and treatment of SARS virus infection. Methods By using phage display technology, we constructed a naive antibody library from convalescent SARS patient lymphocytes. To obtain the neutralizing antibody to SARS virus surface proteins, the library panning procedure was performed on purified SARS virions and the specific Fab antibody clones were enriched by four rounds of repeated panning procedure and screened by highthroughput selection. The selected Fab antibodies expressed in the periplasma of E. coli were soluble and further purified and tested for their binding properties and antiviral function to SARS virus. The functional Fab antibodies were converted to full human IgG antibodies with recombinant baculovirus/insect cell systems and their neutralizing activities were further determined. Results After four rounds of the panning, a number of SARS-CoV virus-targeted human recombinant Fab antibodies were isolated from the SARS patient antibody library. Most of these were identified to recognize both natural and recombinant SARS spike （S） proteins, two Fab antibodies were specific for the virus membrane （M） protein, only one bound to SARS-CoV nucleocapsid protein. The SARS-CoV S and M protein-targeted Fab or IgG antibodies showed significant neutralizing activities in cytopathic effect （CPE） inhibition neutralization test, these antibodies were able to completely neutralize the SARS virus and protect the Vero cells from CPE after virus infection. However, the N protein-targeted Fab or IgG antibodies failed to neutralize the virus. In addition, the SARS N protein-targeted human Fab antibody reacted with the denatured N proteins, whereas none of the S and M protein specific neutralizing antibodies did. These results suggested that the S and M protein-specific neutralizing antibodies could recognize conformational epitopes which might be involved in the binding of virions to cellular receptors and the fusion 展开更多
A novel electrochemical non-enzymatic glucose sensor based on three-dimensional Au/MXene nanocomposites was developed.MXenes were prepared using the mild etched method,and the porous foam of Au nanoparticles was combi...A novel electrochemical non-enzymatic glucose sensor based on three-dimensional Au/MXene nanocomposites was developed.MXenes were prepared using the mild etched method,and the porous foam of Au nanoparticles was combined with the MXene by means of in situ synthesis.By controlling the mass of MXene in the synthesis process,porous foam with Au nanoparticles was obtained.The three-dimensional foam structure of nanoparticles was confirmed by scanning electron microscopy.Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electrochemical performance of the Au/MXene nanocomposites.The Au/MXene nanocomposites acted as a fast redox probe for nonenzymatic glucose oxidation and showed good performance,including a high sensitivity of 22.45μA·(mmol/L)^(-1)·cm^(-1)and a wide linear range of 1-12 mmol/L.Studies have shown that MXene as a catalyst-supported material is beneficial to enhance the conductivity of electrons and increase the loading rate of the catalyst materials.The foam structure with Au nanoparticles can provide a larger surface area,increase the contact area with the molecule in the catalytic reaction,and enhance the electrochemical reaction signal.In summary,this study shows that Au/MXene nanoparticles have the potential to be used in non-enzymatic glucose sensors.展开更多
The synthesis and biodistribution of β-amyloid plaques imaging agent [131I]-2- (4′-dimethylaminophenyl)- 6-iodoimidazo[1,2-α] pyridine ([131I]IMPY) were reported. The chemical structure of the labeling precursor 2...The synthesis and biodistribution of β-amyloid plaques imaging agent [131I]-2- (4′-dimethylaminophenyl)- 6-iodoimidazo[1,2-α] pyridine ([131I]IMPY) were reported. The chemical structure of the labeling precursor 2-(4′-dimethylaminophenyl)-6-(tributylstannyl)imidazo[1,2-α] pyridine and all its intermediates were verified by IR,HNMR and MS. The radioiodinated compound was prepared using iododestannylation reaction by hydrogen per-oxide. Final radiochemical purity was above 95% determined by TLC. The in vivo biodistribution of [131I]IMPY in normal mice showed excellent brain uptake and washout, indicating this thioflavin-T based small molecular probe has potential for in vivo imaging amyloid deposits.展开更多
Through PCR amplification, 5’ flanking region and partial open reading frame（ORF） of gene of Nile tilapia（Oreochromis niloticus） was cloned by PCR amplification. Sequence analysis showed that no difference was fo...Through PCR amplification, 5’ flanking region and partial open reading frame（ORF） of gene of Nile tilapia（Oreochromis niloticus） was cloned by PCR amplification. Sequence analysis showed that no difference was found in known functional regions. This study was to construct and identify the mammalian expression vector of pEGFP-β-actin and to detect whether it could express in HEK 293T cell line. pEGFP-β-actin was transfected into HEK 293T cells with Lipofectamine 2000. The results showed that correct construction of recombinant pEGFP-β-actin has been shown by restriction enzyme digestion. The expression of gene in HEK 293T cells could be observed under microfluoroscope. pEGFP-β-actin could repress EGFP protein in HEK 293T cells. The results showed that β-actin gene promoter possessed effective transcription activities in eukaryotic cells. The work laid foundations for further study on the gene engineering and autotransgenic tilapia.展开更多
The soliton solutions with a double spectral parameter for the principal chiral field are derived by Darboux transformation. The asymptotic behavior of the solutions as time tends to infinity is obtained and the speed...The soliton solutions with a double spectral parameter for the principal chiral field are derived by Darboux transformation. The asymptotic behavior of the solutions as time tends to infinity is obtained and the speeds of the peaks in the asymptotic solutions are not constants.展开更多
The synthesis and biological evaluation of serotonin (5-HTB1AB) imaging agent [P131PI]- 4-iodo-N-{2-[4-(2-methoxyphenyl)-piperazin-1-yl]-ethyl}-N-pridin-2-yl-benzamide ([P131PI]MPPI ) are reported. The chemical struct...The synthesis and biological evaluation of serotonin (5-HTB1AB) imaging agent [P131PI]- 4-iodo-N-{2-[4-(2-methoxyphenyl)-piperazin-1-yl]-ethyl}-N-pridin-2-yl-benzamide ([P131PI]MPPI ) are reported. The chemical structure of aimed compound and intermediates were confirmed by IR, P1PHNMR, and MS. Radiochemical purity was above 99% determined by TLC. Biodistribution of [P131PI]MPPI in rats displayed high uptake in hippocam-pus and low uptake in cerebellum. The ratio of the uptake of [P131PI]MPPI in hippocampus to that in cerebellum was 2.90 at 30 min post injection. The radioactivity in thyroid was 0.069 and 0.128% ID/g organ at 5 min and 120 min, respectively, and it was increased with time, which suggests that in vivo deiodination may be the major route of me-tabolism. Ex vivo autoradiography of brain section displayed significant decrease of radioactivity in hippocampus when pretreated with 8-OH-DPAT, a selective 5HTB1AB agonist, compared with control. These findings strongly sug-gested that P131PI-MPPI could be used as an in vivo marker for studies of pharmacology of the 5-HTB1AB receptor system in animals.展开更多
基金Project(2017YFC1501100)supported by the National Key R&D Program of ChinaProjects(51809221,51679158)supported by the National Natural Science Foundation of China。
文摘To investigate the stability of rock mass in high geostress underground powerhouse caverns subjected to excavation,a microseismic(MS)monitoring system was established and the discrete element method(DEM)-based numerical simulation was carried out.The tempo-spatial damage characteristics of rock mass were analyzed.The evolution laws of MS source parameters during the formation of a rock collapse controlled by high geostress and geological structure were investigated.Additionally,a three-dimensional DEM model of the underground powerhouse caverns was built to reveal the deformation characteristics of rock mass.The results indicated that the MS events induced by excavation of high geostress underground powerhouse caverns occurred frequently.The large-stake crown of the main powerhouse was the main damage area.Prior to the rock collapse,the MS event count and accumulated energy release increased rapidly,while the apparent stress sharply increased and then decreased.The amount and proportion of shear and mixed MS events remarkably increased.The maximum displacement was generally located near the spandrel areas.The MS monitoring data and numerical simulation were in good agreement,which can provide significant references for damage evaluation and disaster forecasting in high geostress underground powerhouse caverns.
基金Projects(51809221,51679158)supported by the National Natural Science Foundation of ChinaProject(KFJJ20-06M)supported by the State Key Laboratory of Explosion Science and Technology(Beijing Institute of Technology),China。
文摘Rock mass large deformation in underground powerhouse caverns has been a severe hazard in hydropower engineering in Southwest China.During the development of rock mass large deformation,a sequence of fractures was generated that can be monitored using microseismic(MS)monitoring techniques.Two MS monitoring systems were established in two typical underground powerhouse caverns featuring distinct geostress levels.The MS b-values associated with rock mass large deformation and their temporal variation are analysed.The results showed that the MS bvalue in course of rock mass deformation was less than 1.0 in the underground powerhouse caverns at a high stress level while larger than 1.5 at a low stress level.Prior to the rock mass deformation,the MS b-values derived from both the high-stress and low-stress underground powerhouse caverns show an incremental decrease over 10%within 10 d.The results contribute to understanding the fracturing characteristics of MS sources associated with rock mass large deformation and provide a reference for early warning of rock mass large deformation in underground powerhouse caverns.
基金This work was supported by the Natural Science Foundation of Hubei Province, China (No.2017CKC891).
文摘High-risk human papillomavirus (hrHPV) infection plays an important role in the development of cervical intraepithelial neoplasia and cervical cancer.A total of 11 549 women were enrolled from the Maternal and Child Health Hospital of Hubei Province.Each participant accepted hrHPV testing and completed a self^administered questionnaire about basic information and potential risk factors.The univariable and multivariable logistic regression model was used to explore the associations between variants and hrHPV infection.Our results showed that hrHPV prevalence was 16.09% in Hubei Province,among which,hrHPV was more likely to be positive in women aged 51 years or above (OR=1.65,95% CI:1.28-2.14),and in women who had symptoms of bleeding after intercourse (OR=1.32,95% CI:1.17-1.50),had first sexual intercourse at the age of 18 years or below (OR=1.33,95% CI:1.07-1.64),had at least three male sexual partners (OR=2.50,95% CI:2.07-3.03),and who had been diagnosed with sexually transmitted infections (OR=1.50,95% CI:1.12-2.03).Married women (OR=0.66,95% CI:0.55-0.78) and women who frequently used condoms (OR=0.75,95% CI:0.67-0.84) had a relatively lower hrHPV prevalence.This study confirms that hrHPV infection was associated with age,marital status,symptoms of intercourse bleeding,history of sexually transmitted infections,and sex-related behaviors.Above all,this study provides a baseline database prior to obtaining vaccinations for dynamic tracking of the changes in hrHPV prevalence.
基金This research was financially supported by National Natural Science Foundation of China(No.22125801,21975005,21878004)Cooperative Research Project of BJUT-NTUT(No.110-03).
文摘Emerging excessive greenhouse gas emissions pose great threats to the ecosystem,which thus requires efficient CO_(2)capture to mitigate the disastrous issue.In this report,large molecular size bisphenol A ethoxylate diacrylate(BPA)was employed to crosslink poly(ethylene glycol)methyl ether acrylate(PEGMEA)via the green and rapid UV polymerization strategy.The microstructure of such-prepared membrane could be conveniently tailored by tuning the ratio of the two prepolymers,aiming at obtaining the optimized microstructures with suitable mesh size and PEO sol content,which was approved by a novel low-field nuclear magnetic resonance technique.The optimum membrane overcomes the tradeoff challenge:dense microstructures lower the gas permeability while loose microstructures lower high-pressure-resistance capacity,realizing a high CO_(2)permeability of 1711 Barrer and 100-h long-term running stability under 15 atm.The proposed membrane fabrication approach,hence,opens a novel gate for developing high-performance robust membranes for CO_(2)capture.
基金The authors gratefully acknowledge the funding from the Natural Science Foundation of China(22125801,22178008)the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(CIT&TCD201904014)+1 种基金Jiayin Yuan is grateful for financial support from Swedish Research Council Grant 2018-05351the Wallenberg Academy Fellow program(Grant KAW 2017.0166)from the Knut&Alice Wallenberg Foundation in Sweden.
文摘Two-dimensional(2D)membrane-based ion separation technology has been increasingly explored to address the problem of lithium resource shortage,yet it remains a sound challenge to design 2D membranes of high selectivity and permeability for ion separation applications.Zeolitic imidazolate framework functionalized modified layered double hydroxide(ZIF-8@MLDH)composite membranes with high lithium-ion(Li^(+)) permeability and excellent operational stability were obtained in this work by in situ depositing functional ZIF-8 nanoparticles into the nanopores acting as framework defects in MLDH membranes.The defect-rich framework amplified the permeability of Li^(+),and the site-selective growth of ZIF-8 in the framework defects bettered its selectivity.Specifically speaking,the ZIF-8@MLDH membranes featured a high permeation rate of Li^(+) up to 1.73 mol m^(−2) h^(−1) and a desirable selectiv-ity of Li^(+)/Mg^(2+) up to 31.9.Simulations supported that the simultaneously enhanced selectivity and permeability of Li+are attributed to changes in the type of mass transfer channels and the difference in the dehydration capacity of hydrated metal cations when they pass through nanochannels of ZIF-8.This study will inspire the ongoing research of high-performance 2D membranes through the engineering of defects.
文摘Background： Renal function is associated with mortality and functional disabilities in stroke patients, and impaired autonomic function is common in stroke, but little is known regarding its effects on stroke patients with renal dysfunction. This study sought to evaluate the association between autonomic function and stroke in patients with renal dysfunction. Methods： This study comprised 232 patients with acute ischemic stroke consecutively enrolled from February 2013 to November 2014 at Guangdong Provincial Hospital of Chinese Medicine in China. All patients recruited underwent laboratory evaluation and 24 h Holter electrocardiography （ECG）. Autonomic function was measured based on the heart rate variability （HRV） using 24 h Holter ECG. Renal damage was assessed through the estimated glomerular filtration rate （eGFR）, and stroke severity was rated according to the National Institutes of Health Stroke Scale （NIHSS）. The Barthel index and modifed Rankin score were also determined following admission. All the clinical covariates that could potentially affect autonomic outcome variables were adjusted with linear regression. Results： In the patients with a mild or moderate decreased eGFR, the values for the standard deviation of the averaged normal-to-normal RR interval （SDANN） index （P = 0.022L very low frequency （VLF） （P = 0.043）, low frequency （LF） （P= 0.023）, and ratio of low-to-high frequency power （LF/HF） （P = 0.001 ） were significantly lower than those in the patients with a normal eGFR. A lnultinomial linear regression indicated that eGFR （t - 2.47, P - 0.014）, gender （t - -3.60, P 〈0.001）, and a history of hypertension （t = -2.65, P = 0.008） were the risk factors of LF/HF; the NIHSS score （SDANN index： t = -3.83, P 〈 0.001 ; VLF： t = -3.07, P = 0.002： LF： t = -2.79, P = 0.006） and a history of diabetes （SDANN index： t = -3.58, P 〈 0.001; VLF： t = -2.54, P = 0.012; LF： t = -2.87, P = 0.004） were independent factors Ib
基金financially supported by the National Natural Science Foundation of China(Nos.21376206 and 21676233)Zhejiang Province Natural Science Foundation(No.LR15B060001)
文摘Polyelectrolyte-surfactant complexes（PESCs） were fabricated through the interaction of poly（acrylic acid） and four different cationic surfactants or their mixtures. PESC membranes were prepared by solution casting method and were applied in ethanol recovery from aqueous solution via pervaporation. Elemental analysis（EA）, Fourier transform infrared spectroscopy（FTIR）, water contact angle（CA） measurement, differential scanning calorimetry（DSC） and X-ray scattering were employed to characterize the composition, structure and properties of PESCs. The results reveal that the investigated PESCs are similar in hydrophobicity but different in hierarchical nanostructures. In separating 5 wt% ethanol/water mixture, PESC membranes with high crystallinity will have both low flux and ethanol selectivity because of the high packing density and low permeability of crystalline regions. Meanwhile, the hierarchical nanostructures of PESC membranes change under pervaporation environment as was revealed by in situ synchrotron radiation X-ray scattering measurement. That is, the crystalline region could melt at high temperature in swelling state, thus consequently enhancing the ethanol selectivity.
基金We are grateful for the financial support of the National Natural Science Foundation of China(Grants No.21376206,21306163,21676233,21776252 and 22125801).
文摘Polymeric nanomaterials,which have tuneable chemical structures,versatile functionalities,and good compatibility with polymeric matrices,have attracted increasing interest from researchers for the construction of polymeric nano-based separation membranes.With their distinctive nanofeatures,polymeric nano-based membranes show great promise in overcoming bottlenecks in polymer membranes,namely,the trade-off between permeability and selectivity,low stability,and fouling issues.Accordingly,recent studies have focused on tuning the structures and tailoring the surface properties of polymeric nano-based membranes via exploitation of membrane fabrication techniques and surface modification strategies,with the objective of pushing the performance of polymeric nano-based membranes to a new level.In this review,first,the approaches for fabricating polymeric nano-based mixed matrix membranes and homogeneous membranes are summarized,such as surface coating,phase inversion,interfacial polymerization,and self-assembly methods.Next,the manipulation strategies of membrane surface properties,namely,the hydrophilicity/hydrophobicity,charge characteristics,and surface roughness,and interior microstructural properties,namely,the pore size and content,channel construction and regulation,are comprehensively discussed.Subsequently,the separation performances of liquid ions/molecules and gas molecules through polymeric nano-based membranes are systematically reported.Finally,we conclude this review with an overview of various unsolved scientific and technical challenges that are associated with new opportunities in the development of advanced polymeric nano-based membranes.
基金supported by the National Natural Science Foundation of China(No.61704035)the Natural Science Foundation of Guangxi Province(2017GXNSFBA198125)the Guangxi Technology Projects(No.AD19110076 and No.AD19110063)。
文摘In this study,the application of bovine serum albumin(BSA)as a carrier to glucose-sensitive materials for the detection of glucose was proposed.Au-Cu O bimetallic nanoclusters(Au-Cu O/BSA)were prepared using BSA as a template,the new sensing material(Au-Cu O/BSA/MWCNTs)was synthesized by mixing with multi-walled carbon nanotubes(MWCNT)and applied to non-enzymatic electrochemical sensors to detect glucose stably and effectively under neutral condition.The scanning electron microscopy was used to investigate the morphology of the synthesized nanocomposite.The electrochemical properties of the sensor were studied by cyclic voltammetry.Glucose detection experiments show that Au-Cu O/BSA/MWCNTs/Au electrode has good glucose detection ability,stability,accuracy,repeatability,and high selectivity in neutral environment.Unlike existing glucose-sensitive materials,due to the use of BSA,the composite material is firmly fixed to the electrode surface without a Nafion solution,which reduces the current blocking effect on the modified electrode.The composite materials can be effectively preserved for extremely long periods,higher than 80%activity is maintained at room temperature in a closed environment for 3 to 4 months,due to the special effects of BSA.In addition,the feasibility of using BSA in glucose-sensitive materials is confirmed.
基金This work was supported by Chinese National "863" R & D High Technology Programs: National SARS Key Project (2003AA208209).
文摘Objective To develop a specific SARS virus-targeted antibody preparation for emergent prophylaxis and treatment of SARS virus infection. Methods By using phage display technology, we constructed a naive antibody library from convalescent SARS patient lymphocytes. To obtain the neutralizing antibody to SARS virus surface proteins, the library panning procedure was performed on purified SARS virions and the specific Fab antibody clones were enriched by four rounds of repeated panning procedure and screened by highthroughput selection. The selected Fab antibodies expressed in the periplasma of E. coli were soluble and further purified and tested for their binding properties and antiviral function to SARS virus. The functional Fab antibodies were converted to full human IgG antibodies with recombinant baculovirus/insect cell systems and their neutralizing activities were further determined. Results After four rounds of the panning, a number of SARS-CoV virus-targeted human recombinant Fab antibodies were isolated from the SARS patient antibody library. Most of these were identified to recognize both natural and recombinant SARS spike （S） proteins, two Fab antibodies were specific for the virus membrane （M） protein, only one bound to SARS-CoV nucleocapsid protein. The SARS-CoV S and M protein-targeted Fab or IgG antibodies showed significant neutralizing activities in cytopathic effect （CPE） inhibition neutralization test, these antibodies were able to completely neutralize the SARS virus and protect the Vero cells from CPE after virus infection. However, the N protein-targeted Fab or IgG antibodies failed to neutralize the virus. In addition, the SARS N protein-targeted human Fab antibody reacted with the denatured N proteins, whereas none of the S and M protein specific neutralizing antibodies did. These results suggested that the S and M protein-specific neutralizing antibodies could recognize conformational epitopes which might be involved in the binding of virions to cellular receptors and the fusion
基金supported by the National Natural Science Foundation of China(No.61704035)the Natural Science Foundation of Guangxi Province(2017GXNSFBA198125)Scientific Research and Technology Development Program of Guangxi(AD19110076,AD19110063)。
文摘A novel electrochemical non-enzymatic glucose sensor based on three-dimensional Au/MXene nanocomposites was developed.MXenes were prepared using the mild etched method,and the porous foam of Au nanoparticles was combined with the MXene by means of in situ synthesis.By controlling the mass of MXene in the synthesis process,porous foam with Au nanoparticles was obtained.The three-dimensional foam structure of nanoparticles was confirmed by scanning electron microscopy.Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electrochemical performance of the Au/MXene nanocomposites.The Au/MXene nanocomposites acted as a fast redox probe for nonenzymatic glucose oxidation and showed good performance,including a high sensitivity of 22.45μA·(mmol/L)^(-1)·cm^(-1)and a wide linear range of 1-12 mmol/L.Studies have shown that MXene as a catalyst-supported material is beneficial to enhance the conductivity of electrons and increase the loading rate of the catalyst materials.The foam structure with Au nanoparticles can provide a larger surface area,increase the contact area with the molecule in the catalytic reaction,and enhance the electrochemical reaction signal.In summary,this study shows that Au/MXene nanoparticles have the potential to be used in non-enzymatic glucose sensors.
基金Jointly supported by a grant from National Natural Science Foundation (30470496), a grant from "135" Medicinal Momentous Pro-ject of Jiangsu Province (RC2002068), a grant from Department of Personnel of Jiangsu Province and a grant from Natural Science Foundation of Jiangsu Province (BK2004423).
文摘The synthesis and biodistribution of β-amyloid plaques imaging agent [131I]-2- (4′-dimethylaminophenyl)- 6-iodoimidazo[1,2-α] pyridine ([131I]IMPY) were reported. The chemical structure of the labeling precursor 2-(4′-dimethylaminophenyl)-6-(tributylstannyl)imidazo[1,2-α] pyridine and all its intermediates were verified by IR,HNMR and MS. The radioiodinated compound was prepared using iododestannylation reaction by hydrogen per-oxide. Final radiochemical purity was above 95% determined by TLC. The in vivo biodistribution of [131I]IMPY in normal mice showed excellent brain uptake and washout, indicating this thioflavin-T based small molecular probe has potential for in vivo imaging amyloid deposits.
基金Supported by China Agriculture Research System(CARS-49)Fujian Seed Industry Innovation and Industrialization(2011FJZY)
文摘Through PCR amplification, 5’ flanking region and partial open reading frame（ORF） of gene of Nile tilapia（Oreochromis niloticus） was cloned by PCR amplification. Sequence analysis showed that no difference was found in known functional regions. This study was to construct and identify the mammalian expression vector of pEGFP-β-actin and to detect whether it could express in HEK 293T cell line. pEGFP-β-actin was transfected into HEK 293T cells with Lipofectamine 2000. The results showed that correct construction of recombinant pEGFP-β-actin has been shown by restriction enzyme digestion. The expression of gene in HEK 293T cells could be observed under microfluoroscope. pEGFP-β-actin could repress EGFP protein in HEK 293T cells. The results showed that β-actin gene promoter possessed effective transcription activities in eukaryotic cells. The work laid foundations for further study on the gene engineering and autotransgenic tilapia.
文摘The soliton solutions with a double spectral parameter for the principal chiral field are derived by Darboux transformation. The asymptotic behavior of the solutions as time tends to infinity is obtained and the speeds of the peaks in the asymptotic solutions are not constants.
基金Supported by grants from National Natural Science Foundation of China (30470496)"135" Medicinal Momentous Project of Jiangsu Province (RC2002068)+1 种基金Jiangsu Natural Science Foundation (BK2004423)Department of Personnel, Jiangsu Province (2003-07).
文摘The synthesis and biological evaluation of serotonin (5-HTB1AB) imaging agent [P131PI]- 4-iodo-N-{2-[4-(2-methoxyphenyl)-piperazin-1-yl]-ethyl}-N-pridin-2-yl-benzamide ([P131PI]MPPI ) are reported. The chemical structure of aimed compound and intermediates were confirmed by IR, P1PHNMR, and MS. Radiochemical purity was above 99% determined by TLC. Biodistribution of [P131PI]MPPI in rats displayed high uptake in hippocam-pus and low uptake in cerebellum. The ratio of the uptake of [P131PI]MPPI in hippocampus to that in cerebellum was 2.90 at 30 min post injection. The radioactivity in thyroid was 0.069 and 0.128% ID/g organ at 5 min and 120 min, respectively, and it was increased with time, which suggests that in vivo deiodination may be the major route of me-tabolism. Ex vivo autoradiography of brain section displayed significant decrease of radioactivity in hippocampus when pretreated with 8-OH-DPAT, a selective 5HTB1AB agonist, compared with control. These findings strongly sug-gested that P131PI-MPPI could be used as an in vivo marker for studies of pharmacology of the 5-HTB1AB receptor system in animals.
