Alloying and interface effects are effective strategies for enhancing the performance of electrocatalysts in energy-related devices.Herein,dendritic Au-doped platinum-palladium alloy/dumbbell-like bismuth telluride he...Alloying and interface effects are effective strategies for enhancing the performance of electrocatalysts in energy-related devices.Herein,dendritic Au-doped platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures(denoted PtPdAu/BiTe)were synthesized using a visible-light-assisted strategy.The coupling alloy and interfacial effects of PtPdAu/BiTe significantly improved the performance and stability of both the ethanol oxidation reaction(EOR)and methanol oxidation reaction(MOR).Introducing a small amount of Au effectively enhanced the CO tolerance of PtPdAu/BiTe compared to dendritic platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures.PtPdAu/BiTe exhibited mass activities of 31.5 and 13.3 A·mg_(Pt)^(-1)in EOR and MOR,respectively,which were 34.4 and 13.2 times higher than those of commercial Pt black,revealing efficient Pt atom utilization.In-situ Fourier transform infrared spectroscopy demonstrated complete 12e^(-)and 6e^(-)oxidation of ethanol and methanol on PtPdAu/BiTe.The PtPdAu/BiTe/C achieved mass peak power densities of 131 and 156 mW·mg_(Pt)^(-1),which were 2.4 and 2.2 times higher than those of Pt/C in practical direct ethanol fuel cell(DEFC)and direct methanol fuel cell(DMFC),respectively,highlighting their potential application in DEFC and DMFC.This study introduces an effective strategy for designing efficient and highly CO tolerant anodic electrocatalysts for practical DEFC and DMFC applications.展开更多
Anovel solid acid catalyst, which was prepared from sodium alginate (SA) and metal chlorides and characterized with XRD and FT-IR spectrometry, was used for the preparation of biodiesel via esterification reaction. Th...Anovel solid acid catalyst, which was prepared from sodium alginate (SA) and metal chlorides and characterized with XRD and FT-IR spectrometry, was used for the preparation of biodiesel via esterification reaction. The study results showed that the aluminum-alginate complex prepared in a cheap and easy way exhibited high catalytic activity, and a 92.6% conversion of methyl oleate was obtained in the presence of 4m% of catalyst dosage upon refluxing for 3h of methanol and acid mixed in a molar ratio of 10:1. It should be noted that the catalyst can be applied to the esterification reaction of fatty acids with various carbon chain length on methanol or different short chain alcohols, indicating that the catalyst is suitable for the preparation of biodiesel from waste oils with a high acid value.展开更多
Objective To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. Methods Mice were immunized intranasally with PBS(negative control), or H3N2 split vaccine...Objective To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. Methods Mice were immunized intranasally with PBS(negative control), or H3N2 split vaccine(3 μg/mouse) alone, or CTA1-DD(5 μg/mouse) alone, or H3N2 split vaccine(3 μg/mouse) plus CTA1-DD(5 μg/mouse). Positive control mice were immunized intramuscularly with H3N2 split vaccine(3 μg/mouse) and alum adjuvant. All the mice were immunized twice, two weeks apart. Then sera and mucosal lavages were collected. The specific HI titers, IgM, IgG, IgA, and IgG subtypes were examined by ELISA. IFN-γ and IL-4 were test by ELISpot. In addition, two weeks after the last immunization, surivival after H3N2 virus lethal challenge was measured. Results H3N2 split vaccine formulated with CTA1-DD could elicit higher Ig M, Ig G and hemagglutination inhibition titers in sera. Furthermore, using CTA1-DD as adjuvant significantly improved mucosal secretory Ig A titers in bronchoalveolar lavages and vaginal lavages. Meanwhile this mucosal adjuvant could enhance Th-1-type responses and induce protective hemagglutination inhibition titers. Notably, the addition of CTA1-DD to split vaccine provided 100% protection against lethal infection by the H3N2 virus. Conclusion CTA1-DD could promote mucosal, humoral and cell-mediated immune responses, which supports the further development of CTA1-DD as a mucosal adjuvant for mucosal vaccines.展开更多
The phyA^m gene encoding acid phytase and optimized neutral phytase phyCs gene were inserted into expression vector pPIC9K in correct orientation and transformed into Pichiapastoris in order to expand the pH profile o...The phyA^m gene encoding acid phytase and optimized neutral phytase phyCs gene were inserted into expression vector pPIC9K in correct orientation and transformed into Pichiapastoris in order to expand the pH profile ofphytase and decrease the cost of production. The fusion phytase phyA^m-phyCs gene was successfully overexpressed in P. pastoris as an active and extracellular phytase. The yield of total extracellular fusion phytase activity is （25.4±0.53） U/ml at the flask scale and （159.1±2.92） U/ml for high cell-density fermentation, respectively. Purified fusion phytase exhibits an optimal temperature at 55 ℃ and an optimal pH at 5.5-6.0 and its relative activity remains at a relatively high level of above 70% in the range ofpH 2.0 to 7.0. About 51% to 63% of its original activity remains after incubation at 75 ℃ to 95 ℃ for 10 min. Due to heavy glycosylation, the expressed fusion phytase shows a broad and diffuse band in SDS-PAGE （sodium dodecyl sulfate-polyacrylamide gel electrophoresis）. After deglycosylation by endoglycosidase H （EndoHf）, the enzyme has an apparent molecular size of 95 kDa. The characterization of the fusion phytase was compared with those ofphyCs andphyA^m.展开更多
Based on the principle of fluid mechanics a mathematical model of the oval gallbladder’smoving boundaries was obtained by CT,radio contrast radiography and B mode echography.Weadopted for the first time in this field...Based on the principle of fluid mechanics a mathematical model of the oval gallbladder’smoving boundaries was obtained by CT,radio contrast radiography and B mode echography.Weadopted for the first time in this field,the finite element method to calculate the transient flow fieldwithin the human gallbladder in vivo and successfully made out the distribution of bile flow withinthe cyst,known as Newtonian fluid and axisymmetric flow.Thus we completed the poineering ofthe bile flow study within the gallbladder,and confirmed the way of the cholelithogenesis withinthe cyst.Theoretically the vortex flow is proved to be the mechanical factor in the formation ofgallbladder stone and several conclusions were drawn from this study:(1)near the axis of thecontacting gallbladder exists an accelerated bile out-flow column;(2)near the central cross-section ofthe flow field there exist two opposed vortex areas,the one which near the axis rotatescounterwise and flows faster;(3)a gross similarity exists between the law of attenuation of bile flowvelocity and the gallbladder contraction;(4)chololithogenesis within the cyst is related to the vortex inthe flow field.展开更多
The posttranslational modification of proteins with complex carbohydrate moieties(glycosylation)regulates the process of fruit ripening.Exoglycosidases are enzymes that can trim this protein glycosylation and are ther...The posttranslational modification of proteins with complex carbohydrate moieties(glycosylation)regulates the process of fruit ripening.Exoglycosidases are enzymes that can trim this protein glycosylation and are therefore considered to be important targets in the control of fruit ripening and softening.Melting-type peaches are popular seasonal fruits in many Asian regions,but the extremely short shelf-life of the peach fruits significantly hampers their economic value.To investigate the effect of the protein glycosylation and exoglycosidase activities on the development and ripening of the peach fruit,the fruit flesh of the melting peach cultivar'Xia hui 6'at five different maturity stages were analyzed.The N-glycan profile of each sample was characterized and quantified by HILIC-UPLC and MALDI-TOF mass spectrometry,revealing two characteristic N-glycan structures(MMXF and GnGnMXF)which were strongly affected by the state of maturity.Furthermore,it was shown that one of the endogenous exoglycosidase activities analyzed(β-N-acetylhexosaminidase,β-Hex)correlated with the MMXF and GnGnMXF N-glycan structures(p<0.05)in an obverse manner.These findings lay the foundation for further elucidation of the physiological functions of protein glycosylation in peach fruit development and ripening.展开更多
In this report we illustrate our application of soft lithography-based microfabrication,surface modification,and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual ...In this report we illustrate our application of soft lithography-based microfabrication,surface modification,and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual forebrain neurons from Day 7 embryonic chicks into two rows of eight in a silicon microstructure aligned over a microelectrode array (MEA). The polydimethylsiloxane (PDMS) membrane with microstructures to confine cells and guide network connectivity was aligned to the electrodes of a MEA. Both the MEA and the PDMS membrane were treated with O2 plasma,Poly-L-Lysine,and Laminin to aid in cell attachment and survival. The primary advantage of our process is that it is quicker and simpler than previous cell-placement methods and may make highly defined neuronal network biochips more practical.展开更多
Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface ant...Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface antigen (HBsAg) is a key target molecule in developing vaccines and diagnostic systems. To date, although HBsAg has been expressed in bacteria, yeasts and mammalian cells, there are still limitations in the existing ones, which leave the necessity for searching new HBsAg production methods. In this study, a simple phage display-based method was developed to produce the purified full-length HBsAg molecules for further immunization studies. For this purpose, the HBsAg coding gene was cloned into a pCANTAB5E phagemid vector and expressed on the surface of M13 filamentous phages. The HBsAg-expressing phage nanosystem was then used as immunization agent in BALB/cJ mice. The ELISA results for sera obtained from mice immunized with HBsAg-displaying phage particles revealed an immune response against HBsAg. These results demonstrate the potential use of a full-length antigen to be displayed on phages as cost effective adjuvant-free immunization agents as an alternative to the highly purified and more expensive antigens conjugated with carrier molecules.展开更多
We describe two novel approaches for the determination of glucosamine(GlcN).The first approach is based on the chemical derivatization of GlcN with the non-fluorophor 1,3-diphenyl-1,3-propanedione(DPPD),which results ...We describe two novel approaches for the determination of glucosamine(GlcN).The first approach is based on the chemical derivatization of GlcN with the non-fluorophor 1,3-diphenyl-1,3-propanedione(DPPD),which results in a condensation product with interesting fluorescent properties.The obtained compound was isolated by silica-gel chromatography and its structure elucidated by NMR and mass spectrometry.The second approach is based on a previously undescribed sensitivity of the enzyme glucosamine-6-phosphate deaminase(GPDA)towards GlcN,which resulted in the precipitation of the enzyme.Using a rational enzyme engineering approach and both liquid-based and plate-based screening methods,mutational GPDA variants with significantly improved precipitation properties were identified and characterized.These novel glucosamine detection methods may be a useful addition to the repertoire of currently available glucosamine detection sensors.展开更多
Plant-based systems offer a cost-effective platform for the production of pharmaceutical proteins;however,the instability and rapid degradation of certain proteins,such as epidermal growth factor(EGF),present signific...Plant-based systems offer a cost-effective platform for the production of pharmaceutical proteins;however,the instability and rapid degradation of certain proteins,such as epidermal growth factor(EGF),present significant challenges.To enhance EGF accumulation,we specifically targeted the protein to distinct subcellular compartments.In these experiments,most protein constructs contained a C-terminal hemagglutinin(HA)tag,enabling detection using anti-HA antibodies.Targeting EGF to the chloroplast and retained endoplasmic reticulum(ER)was successful,with significantly higher accumulation observed in the ER compared to the chloroplast(Figure S1A).展开更多
Optoacoustic signals behave nonlinearly at light fluences above a few mJ/cm^(2),which may affect the interpretation and quantification of measurements.It has been proposed that optoacoustic nonlinearity arises from th...Optoacoustic signals behave nonlinearly at light fluences above a few mJ/cm^(2),which may affect the interpretation and quantification of measurements.It has been proposed that optoacoustic nonlinearity arises from the heat-induced formation of nanobubbles or changes in local thermo-physical parameters.However,such explanations are only valid at much higher fluences than typically used in biomedical optoacoustic imaging(>20 mJ/cm^(2))or in the presence of materials with high absorption coefficients such as gold nanoparticles.We propose herein that electromagnetic permittivity changes in response to photon absorption are major source of optoacoustic signal nonlinearity at low fluences.We provide theoretical and experimental evidence that supports this postulation and show that optoacoustic pressure responses due to permittivity changes,which are function of thermally excited third-order nonlinear susceptibility,can explain the nonlinear behavior of the optoacoustic signal.Since different materials exhibit different thermally excited third-order nonlinear susceptibility,this property could function as a new contrast mechanism that can identify the sensitivity of a substance’s dielectric constant to photon-induced temperature changes.Consequently,we propose an imaging method based on nonlinear optoacoustic signals that exploits this newly identified contrast mechanism.These findings may have far-reaching implications for improving the accuracy of optoacoustics and utilizing the proposed new contrast mechanism would advance our understanding of cellular and tissue functionality.展开更多
Cervical spinal canal narrowing can lead to injury of the spinal cord and neurological symptoms including neck pain,headache,weakness and parasthesisas.According to previous and recent clinical researches,we investiga...Cervical spinal canal narrowing can lead to injury of the spinal cord and neurological symptoms including neck pain,headache,weakness and parasthesisas.According to previous and recent clinical researches,we investigated the geometric parameters of normal cervical spinal canal including the sagittal and transverse diameters as well as Torg ratio.The mean sagittal diameter of cervical spinal canal at C1 to C7 ranges from 15.33 mm to 20.46 mm,the mean transverse diameter at the same levels ranges from 24.45 mm to 27.00 mm and the mean value of Torg ratio is 0.96.With respect to narrow cervical spinal canal,the following charaterstics are found：firstly,extension of the cervical spine results in statistically significant stenosis as compared with the flexed or neutral positions; secondly,females sustain cervical spinal canal narrowing more easily than males;finally,the consistent narrowest cervical canal level is at C4 for all ethnicity,but there is a slight variation in the sagittal diameter of cervical spinal stenosis（≤ 14 mm in Whites,≤12 mm in Japanese,≤ 13.7 mm in Chinese）.Narrow sagittal cervical canal diameter brings about an increased risk of neurological injuries in traumatic,degenerative and inflammatory conditions and is related with extension of cervical spine,gender,as well as ethnicity.It is hoped that this review will be helpful in diagnosing spinal cord and neurological injuries with the geometric parameters of cervical spine in the future.展开更多
Despite a large number of rear-end collisions on the road and a high frequency of whiplash injuries reported, the mechanism of whiplash injuries is not completely understood. One of the reasons is that the injury is n...Despite a large number of rear-end collisions on the road and a high frequency of whiplash injuries reported, the mechanism of whiplash injuries is not completely understood. One of the reasons is that the injury is not necessarily accompanied by obvious tissue damage detectable by X-ray or MRI. An extensive series of biomechanics studies, including injury epidemiology, neck kinematics,facet capsule ligament mechanics, injury mechanisms and injury criteria, were undertaken to help elucidate these whiplash injury mechanisms and gain a better understanding of cervical facet pain. These studies provide the following evidences to help explain the mechanisms of the whiplash injury: (1) Whiplash injuries are generally considered to be a soft tissue injury of the neck with symptoms such as neck pain and stiffness, shoulder weakness, dizziness, headache and memory loss, etc. (2) Based on kinematical studies on the cadaver and volunteers, there are three distinct periods that have the potential to cause injury to the neck. In the first stage, flexural deformation of the neck is observed along with a loss of cervical lordosis; in the second stage, the cervical spine assumes an S-shaped curve as the lower vertebrae begin to extend and gradually cause the upper vertebrae to extend; during the final stage, the entire neck is extended due to the extension moments at both ends. (3)The in vivo environment afforded by rodent models of injury offers particular utility for linking mechanics, nociception and behavioral outcomes. Experimental findings have examined strains across the facet joint as a mechanism of whiplash injury, and suggested a capsular strain threshold or a vertebral distraction threshold for whiplash-related injury,potentially producing neck pain. (4) Injuries to the facet capsule region of the neck are a major source of post-crash pain. There are several hypotheses on how whiplash-associated injury may occur and three of these injuries are related to strains within the facet capsule connected with events early in the impact. (5) There are several possible injury criteria to correlate with the duration of symptoms during reconstructions of actual crashes. These results form the biomechanical basis for a hypothesis that the facet joint capsule is a source of neck pain and that the pain may arise from large strains in the joint capsule that will cause pain receptors to fire.展开更多
Cervical spondylosis refers to degenerative changes in the sub-axial cervical spine.Symptoms caused by spondylosis include axial neck pain,cervical radiculopathy,and cervical myelopathy.One of the most commonly used s...Cervical spondylosis refers to degenerative changes in the sub-axial cervical spine.Symptoms caused by spondylosis include axial neck pain,cervical radiculopathy,and cervical myelopathy.One of the most commonly used surgical treatments is anterior cervical discectomy and fusion(ACDF);it is reported that ACDF leads to the development of progressive adjacent segment degeneration(ASD)in over 90%of the patients with up to 25.6%requiring reoperations due to symptomatic ASD.展开更多
基金supported by the National Natural Science Foundation of China(No.22465009)the Education Department of Guizhou Province(No.2021312)the Foundation of Guizhou Province(No.2019-5666).
文摘Alloying and interface effects are effective strategies for enhancing the performance of electrocatalysts in energy-related devices.Herein,dendritic Au-doped platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures(denoted PtPdAu/BiTe)were synthesized using a visible-light-assisted strategy.The coupling alloy and interfacial effects of PtPdAu/BiTe significantly improved the performance and stability of both the ethanol oxidation reaction(EOR)and methanol oxidation reaction(MOR).Introducing a small amount of Au effectively enhanced the CO tolerance of PtPdAu/BiTe compared to dendritic platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures.PtPdAu/BiTe exhibited mass activities of 31.5 and 13.3 A·mg_(Pt)^(-1)in EOR and MOR,respectively,which were 34.4 and 13.2 times higher than those of commercial Pt black,revealing efficient Pt atom utilization.In-situ Fourier transform infrared spectroscopy demonstrated complete 12e^(-)and 6e^(-)oxidation of ethanol and methanol on PtPdAu/BiTe.The PtPdAu/BiTe/C achieved mass peak power densities of 131 and 156 mW·mg_(Pt)^(-1),which were 2.4 and 2.2 times higher than those of Pt/C in practical direct ethanol fuel cell(DEFC)and direct methanol fuel cell(DMFC),respectively,highlighting their potential application in DEFC and DMFC.This study introduces an effective strategy for designing efficient and highly CO tolerant anodic electrocatalysts for practical DEFC and DMFC applications.
基金financially supported by the International Science & Technology Cooperation Program of China(No.2010DFB60840)the Key Science and Technology Project of Guizhou Province(No.20076004)+1 种基金the Social Development S&T Program(No.SZ-[2009]3011)the National Key Technology R&D Program(No.2006BAD07A12)
文摘Anovel solid acid catalyst, which was prepared from sodium alginate (SA) and metal chlorides and characterized with XRD and FT-IR spectrometry, was used for the preparation of biodiesel via esterification reaction. The study results showed that the aluminum-alginate complex prepared in a cheap and easy way exhibited high catalytic activity, and a 92.6% conversion of methyl oleate was obtained in the presence of 4m% of catalyst dosage upon refluxing for 3h of methanol and acid mixed in a molar ratio of 10:1. It should be noted that the catalyst can be applied to the esterification reaction of fatty acids with various carbon chain length on methanol or different short chain alcohols, indicating that the catalyst is suitable for the preparation of biodiesel from waste oils with a high acid value.
基金supported by the Chinese National Science and Technology Major Project for Important Infectious Diseases Control and Prevention [Grant No.2017ZX10105015001002]
文摘Objective To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. Methods Mice were immunized intranasally with PBS(negative control), or H3N2 split vaccine(3 μg/mouse) alone, or CTA1-DD(5 μg/mouse) alone, or H3N2 split vaccine(3 μg/mouse) plus CTA1-DD(5 μg/mouse). Positive control mice were immunized intramuscularly with H3N2 split vaccine(3 μg/mouse) and alum adjuvant. All the mice were immunized twice, two weeks apart. Then sera and mucosal lavages were collected. The specific HI titers, IgM, IgG, IgA, and IgG subtypes were examined by ELISA. IFN-γ and IL-4 were test by ELISpot. In addition, two weeks after the last immunization, surivival after H3N2 virus lethal challenge was measured. Results H3N2 split vaccine formulated with CTA1-DD could elicit higher Ig M, Ig G and hemagglutination inhibition titers in sera. Furthermore, using CTA1-DD as adjuvant significantly improved mucosal secretory Ig A titers in bronchoalveolar lavages and vaginal lavages. Meanwhile this mucosal adjuvant could enhance Th-1-type responses and induce protective hemagglutination inhibition titers. Notably, the addition of CTA1-DD to split vaccine provided 100% protection against lethal infection by the H3N2 virus. Conclusion CTA1-DD could promote mucosal, humoral and cell-mediated immune responses, which supports the further development of CTA1-DD as a mucosal adjuvant for mucosal vaccines.
基金the National Key Technologies R & D Program of China during the 10th Five-Year Plan Period (No. 2002BA514A-12)the Education Department of Sichuan Province (No. 2006B014)the Innovative Fund for Distinguished Young Scholars of Sichuan Agricultural University, China
文摘The phyA^m gene encoding acid phytase and optimized neutral phytase phyCs gene were inserted into expression vector pPIC9K in correct orientation and transformed into Pichiapastoris in order to expand the pH profile ofphytase and decrease the cost of production. The fusion phytase phyA^m-phyCs gene was successfully overexpressed in P. pastoris as an active and extracellular phytase. The yield of total extracellular fusion phytase activity is （25.4±0.53） U/ml at the flask scale and （159.1±2.92） U/ml for high cell-density fermentation, respectively. Purified fusion phytase exhibits an optimal temperature at 55 ℃ and an optimal pH at 5.5-6.0 and its relative activity remains at a relatively high level of above 70% in the range ofpH 2.0 to 7.0. About 51% to 63% of its original activity remains after incubation at 75 ℃ to 95 ℃ for 10 min. Due to heavy glycosylation, the expressed fusion phytase shows a broad and diffuse band in SDS-PAGE （sodium dodecyl sulfate-polyacrylamide gel electrophoresis）. After deglycosylation by endoglycosidase H （EndoHf）, the enzyme has an apparent molecular size of 95 kDa. The characterization of the fusion phytase was compared with those ofphyCs andphyA^m.
文摘Based on the principle of fluid mechanics a mathematical model of the oval gallbladder’smoving boundaries was obtained by CT,radio contrast radiography and B mode echography.Weadopted for the first time in this field,the finite element method to calculate the transient flow fieldwithin the human gallbladder in vivo and successfully made out the distribution of bile flow withinthe cyst,known as Newtonian fluid and axisymmetric flow.Thus we completed the poineering ofthe bile flow study within the gallbladder,and confirmed the way of the cholelithogenesis withinthe cyst.Theoretically the vortex flow is proved to be the mechanical factor in the formation ofgallbladder stone and several conclusions were drawn from this study:(1)near the axis of thecontacting gallbladder exists an accelerated bile out-flow column;(2)near the central cross-section ofthe flow field there exist two opposed vortex areas,the one which near the axis rotatescounterwise and flows faster;(3)a gross similarity exists between the law of attenuation of bile flowvelocity and the gallbladder contraction;(4)chololithogenesis within the cyst is related to the vortex inthe flow field.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions (grant KYZ201824 to Ting Wang)the National Natural Science Foundation of China (NSFC grants 31471703,31671854,31871793 and 31871754 to Josef Voglmeir and Li Liu).
文摘The posttranslational modification of proteins with complex carbohydrate moieties(glycosylation)regulates the process of fruit ripening.Exoglycosidases are enzymes that can trim this protein glycosylation and are therefore considered to be important targets in the control of fruit ripening and softening.Melting-type peaches are popular seasonal fruits in many Asian regions,but the extremely short shelf-life of the peach fruits significantly hampers their economic value.To investigate the effect of the protein glycosylation and exoglycosidase activities on the development and ripening of the peach fruit,the fruit flesh of the melting peach cultivar'Xia hui 6'at five different maturity stages were analyzed.The N-glycan profile of each sample was characterized and quantified by HILIC-UPLC and MALDI-TOF mass spectrometry,revealing two characteristic N-glycan structures(MMXF and GnGnMXF)which were strongly affected by the state of maturity.Furthermore,it was shown that one of the endogenous exoglycosidase activities analyzed(β-N-acetylhexosaminidase,β-Hex)correlated with the MMXF and GnGnMXF N-glycan structures(p<0.05)in an obverse manner.These findings lay the foundation for further elucidation of the physiological functions of protein glycosylation in peach fruit development and ripening.
基金South Carolina Spinal Cord Injury Association (Grant No.SCIRF 0303)AHA (0565445U)+2 种基金NIH SC INBRE (Grant No.2p20RR16461-05)DoD Era of Hope Award (BC044778)NIH Career Award (1K25HL088262-01)
文摘In this report we illustrate our application of soft lithography-based microfabrication,surface modification,and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual forebrain neurons from Day 7 embryonic chicks into two rows of eight in a silicon microstructure aligned over a microelectrode array (MEA). The polydimethylsiloxane (PDMS) membrane with microstructures to confine cells and guide network connectivity was aligned to the electrodes of a MEA. Both the MEA and the PDMS membrane were treated with O2 plasma,Poly-L-Lysine,and Laminin to aid in cell attachment and survival. The primary advantage of our process is that it is quicker and simpler than previous cell-placement methods and may make highly defined neuronal network biochips more practical.
文摘Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface antigen (HBsAg) is a key target molecule in developing vaccines and diagnostic systems. To date, although HBsAg has been expressed in bacteria, yeasts and mammalian cells, there are still limitations in the existing ones, which leave the necessity for searching new HBsAg production methods. In this study, a simple phage display-based method was developed to produce the purified full-length HBsAg molecules for further immunization studies. For this purpose, the HBsAg coding gene was cloned into a pCANTAB5E phagemid vector and expressed on the surface of M13 filamentous phages. The HBsAg-expressing phage nanosystem was then used as immunization agent in BALB/cJ mice. The ELISA results for sera obtained from mice immunized with HBsAg-displaying phage particles revealed an immune response against HBsAg. These results demonstrate the potential use of a full-length antigen to be displayed on phages as cost effective adjuvant-free immunization agents as an alternative to the highly purified and more expensive antigens conjugated with carrier molecules.
基金supported in parts by the National Natural Science Foundation of China (grant numbers 31471703,31671854,and 31871754)the 100 Foreign Talents Plan (grant number JSB2014012).
文摘We describe two novel approaches for the determination of glucosamine(GlcN).The first approach is based on the chemical derivatization of GlcN with the non-fluorophor 1,3-diphenyl-1,3-propanedione(DPPD),which results in a condensation product with interesting fluorescent properties.The obtained compound was isolated by silica-gel chromatography and its structure elucidated by NMR and mass spectrometry.The second approach is based on a previously undescribed sensitivity of the enzyme glucosamine-6-phosphate deaminase(GPDA)towards GlcN,which resulted in the precipitation of the enzyme.Using a rational enzyme engineering approach and both liquid-based and plate-based screening methods,mutational GPDA variants with significantly improved precipitation properties were identified and characterized.These novel glucosamine detection methods may be a useful addition to the repertoire of currently available glucosamine detection sensors.
基金funded by the Korean Research Institute Bio-science and Biotechnology(KRIBB)Research Initiative Programs Grant Nos.KGM9942522,KGM1082511,KGM1002521National Research Foundation of Korea(NRF)Grant No.RS-2025-00556557New Breeding Technology Program Grant No.RS-2024-00322156 to H.C.
文摘Plant-based systems offer a cost-effective platform for the production of pharmaceutical proteins;however,the instability and rapid degradation of certain proteins,such as epidermal growth factor(EGF),present significant challenges.To enhance EGF accumulation,we specifically targeted the protein to distinct subcellular compartments.In these experiments,most protein constructs contained a C-terminal hemagglutinin(HA)tag,enabling detection using anti-HA antibodies.Targeting EGF to the chloroplast and retained endoplasmic reticulum(ER)was successful,with significantly higher accumulation observed in the ER compared to the chloroplast(Figure S1A).
基金funded by the European Union under the 7th Framework Program grant agreement no 605162(BERTI)the European Union’s Horizon 2020 research and innovation programme under grant agreement no.687866(INNODERM)and no.862811(RSENSE)+3 种基金the Deutsche Forschungsgemeinschaft(DFG)as part of the CRC 1123(Z1)funding from the European Commission grant agreement No 801347(SENSITIVE)Spanish Ministry of Economy and Competitiveness(MINECO)Grant FIS2016-77892-Rthe Alexander von Humboldt Postdoctoral Fellowship program.
文摘Optoacoustic signals behave nonlinearly at light fluences above a few mJ/cm^(2),which may affect the interpretation and quantification of measurements.It has been proposed that optoacoustic nonlinearity arises from the heat-induced formation of nanobubbles or changes in local thermo-physical parameters.However,such explanations are only valid at much higher fluences than typically used in biomedical optoacoustic imaging(>20 mJ/cm^(2))or in the presence of materials with high absorption coefficients such as gold nanoparticles.We propose herein that electromagnetic permittivity changes in response to photon absorption are major source of optoacoustic signal nonlinearity at low fluences.We provide theoretical and experimental evidence that supports this postulation and show that optoacoustic pressure responses due to permittivity changes,which are function of thermally excited third-order nonlinear susceptibility,can explain the nonlinear behavior of the optoacoustic signal.Since different materials exhibit different thermally excited third-order nonlinear susceptibility,this property could function as a new contrast mechanism that can identify the sensitivity of a substance’s dielectric constant to photon-induced temperature changes.Consequently,we propose an imaging method based on nonlinear optoacoustic signals that exploits this newly identified contrast mechanism.These findings may have far-reaching implications for improving the accuracy of optoacoustics and utilizing the proposed new contrast mechanism would advance our understanding of cellular and tissue functionality.
文摘Cervical spinal canal narrowing can lead to injury of the spinal cord and neurological symptoms including neck pain,headache,weakness and parasthesisas.According to previous and recent clinical researches,we investigated the geometric parameters of normal cervical spinal canal including the sagittal and transverse diameters as well as Torg ratio.The mean sagittal diameter of cervical spinal canal at C1 to C7 ranges from 15.33 mm to 20.46 mm,the mean transverse diameter at the same levels ranges from 24.45 mm to 27.00 mm and the mean value of Torg ratio is 0.96.With respect to narrow cervical spinal canal,the following charaterstics are found：firstly,extension of the cervical spine results in statistically significant stenosis as compared with the flexed or neutral positions; secondly,females sustain cervical spinal canal narrowing more easily than males;finally,the consistent narrowest cervical canal level is at C4 for all ethnicity,but there is a slight variation in the sagittal diameter of cervical spinal stenosis（≤ 14 mm in Whites,≤12 mm in Japanese,≤ 13.7 mm in Chinese）.Narrow sagittal cervical canal diameter brings about an increased risk of neurological injuries in traumatic,degenerative and inflammatory conditions and is related with extension of cervical spine,gender,as well as ethnicity.It is hoped that this review will be helpful in diagnosing spinal cord and neurological injuries with the geometric parameters of cervical spine in the future.
基金General Motors Corporation (GM) and National Natural Science Foundation of China (NSFC) pursuant to an agreement between GM and NSFC，Natural Science Foundation Project of CQ CSTC
文摘Despite a large number of rear-end collisions on the road and a high frequency of whiplash injuries reported, the mechanism of whiplash injuries is not completely understood. One of the reasons is that the injury is not necessarily accompanied by obvious tissue damage detectable by X-ray or MRI. An extensive series of biomechanics studies, including injury epidemiology, neck kinematics,facet capsule ligament mechanics, injury mechanisms and injury criteria, were undertaken to help elucidate these whiplash injury mechanisms and gain a better understanding of cervical facet pain. These studies provide the following evidences to help explain the mechanisms of the whiplash injury: (1) Whiplash injuries are generally considered to be a soft tissue injury of the neck with symptoms such as neck pain and stiffness, shoulder weakness, dizziness, headache and memory loss, etc. (2) Based on kinematical studies on the cadaver and volunteers, there are three distinct periods that have the potential to cause injury to the neck. In the first stage, flexural deformation of the neck is observed along with a loss of cervical lordosis; in the second stage, the cervical spine assumes an S-shaped curve as the lower vertebrae begin to extend and gradually cause the upper vertebrae to extend; during the final stage, the entire neck is extended due to the extension moments at both ends. (3)The in vivo environment afforded by rodent models of injury offers particular utility for linking mechanics, nociception and behavioral outcomes. Experimental findings have examined strains across the facet joint as a mechanism of whiplash injury, and suggested a capsular strain threshold or a vertebral distraction threshold for whiplash-related injury,potentially producing neck pain. (4) Injuries to the facet capsule region of the neck are a major source of post-crash pain. There are several hypotheses on how whiplash-associated injury may occur and three of these injuries are related to strains within the facet capsule connected with events early in the impact. (5) There are several possible injury criteria to correlate with the duration of symptoms during reconstructions of actual crashes. These results form the biomechanical basis for a hypothesis that the facet joint capsule is a source of neck pain and that the pain may arise from large strains in the joint capsule that will cause pain receptors to fire.
基金This study was supported by the National Institutes of Health(1R03AG056897),and the first author was funded by a doctor scholarship(GZSYBS[2017]12)from the Guizhou Provincial People's Hospital,Guiyang,China.
文摘Cervical spondylosis refers to degenerative changes in the sub-axial cervical spine.Symptoms caused by spondylosis include axial neck pain,cervical radiculopathy,and cervical myelopathy.One of the most commonly used surgical treatments is anterior cervical discectomy and fusion(ACDF);it is reported that ACDF leads to the development of progressive adjacent segment degeneration(ASD)in over 90%of the patients with up to 25.6%requiring reoperations due to symptomatic ASD.
