Background: Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in Western societies and are rapidly becoming a worldwide health problem. African-Americans have increased morbidity and morta...Background: Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in Western societies and are rapidly becoming a worldwide health problem. African-Americans have increased morbidity and mortality rates from CVD. Our study aimed to assess the effects of the CVD risk factors burden alone versus with diabetes mellitus in a high riskCVDpopulation. Methods: The two study groups consisted of thirty seven diabetics and thirty seven non-diabetic African-Americans aged ≥55 years without clinical atherosclerosis having similar cardiovascular risk factors (age, hypertension, hypercholesterolemia, smoking, and body mass index) except for diabetes mellitus. Brachial artery flow-mediated dilation (FMD), Nitroglycerin-mediated dilatation (NMD) and carotid intima-media thickness (IMT) were recorded in all subjects. Results: Endothelial function as assessed by the brachial artery FMD was significantly impaired in the diabetic group compared to the non-diabetic group (7.8 ± 5 vs 3.3 ± 4;p = 0.0001). There were no differences in neither Nitroglycerin-mediated dilatation (NMD) nor carotid intima-media thickness (IMT) in the diabetic and non-diabetic groups. Conclusion: The contribution of diabetes to the development of endothelial dysfunction in subjects with clustering of CVD risk factors may be early as indicated by significant functional changes preceeding structural vascular changes..展开更多
Cu wires(CuWs)are widely used as electric transmission lines.However,their limited thermal and chemical stabilities become challenges under the high-power and harsh environment.Graphene is regarded as an ideal protect...Cu wires(CuWs)are widely used as electric transmission lines.However,their limited thermal and chemical stabilities become challenges under the high-power and harsh environment.Graphene is regarded as an ideal protective barrier for CuW benefiting from its impermeability to all atoms and molecules.Particularly,the excellent hydrophobicity of vertical graphene(VG)will strengthen its protective capability as a corrosion and oxidation barrier.Herein,VG is directly synthesized on CuW by plasmaenhanced chemical vapor deposition method.The hydrophobic VG coating with a high water contact angle can effectively exclude the corrosive liquid and moisture from CuW surface and prevent their further penetration.Consequently,the electrochemical corrosion rate of VG-CuW is reduced by~13,8,and 2 times,compared with bare CuW,VG-CuW with hydrophilic treatment,and CuW coated with thick horizontal graphene layers,respectively.Negligible oxidation occurs on VGCuW after the long-time exposure to humid air at~200℃ along with the largely enhanced tolerance under high-current operating condition.This study reveals the impressive potentials of hydrophobic VG as a robust corrosion and oxidation barrier for metal wires used in high-power cables and electronic devices in harsh environment.展开更多
With the continuous advancements in electronics towards downsizing and integration,efficient thermal dissipation from chips has emerged as a critical factor affecting their lifespan and operational efficiency.The fan-...With the continuous advancements in electronics towards downsizing and integration,efficient thermal dissipation from chips has emerged as a critical factor affecting their lifespan and operational efficiency.The fan-less chip cooling system has two critical interfaces for thermal transport,which are the contact interface between the base and the chip dominated by thermal conduction,and the surface of the fins dominated by thermal radiation.The different thermal transfer modes of these two critical interfaces pose different requirements for thermal management materials.In the study,a novel approach was proposed by developing graphene thermal transport functional material whose morphology could be intentionally designed via reformed plasmaenhanced chemical vapor deposition(PECVD)methods to meet the diverse requirements of heat transfer properties.Specifically,graphene with multilevel branching structure of vertical graphene(BVG)was fabricated through the hydrogenassisted PECVD(H_(2)-PECVD)strategy,which contributed a high emissivity of~0.98.BVG was deposited on the fins’surface and functioned as the radiation enhanced layer to facilitate the rapid radiation of heat from the heat sinks into the surrounding air.Meanwhile,the well-oriented vertical graphene(OVG)was successfully prepared through the vertical electric field-assisted PECVD process(EF-PECVD),which showed a high directional thermal conductivity of~53.5 W·m^(-1)·K^(-1).OVG was deposited on the contact interface and functioned as the thermal conduction enhanced layer,allowing for the quick transmission of heat from the chip to the heat sink.Utilizing this design concept,the two critical interfaces in the chip cooling system can be jointly enhanced,resulting in a remarkable cooling efficiency enhancement of~30.7%,demonstrating that this novel material possessed enormous potential for enhancing the performance of cooling systems.Therefore,this research not only provided new design concepts for the cooling system of electronic devices but also opened up new avenues for the application of graphene materials in thermal management.展开更多
Anaplastic thyroid cancer(ATC)is a rare but highly lethal disease.ATCs are resistant to standard therapies and are extremely difficult to manage.The stepwise cell dedifferentiation results in the impairment of the iod...Anaplastic thyroid cancer(ATC)is a rare but highly lethal disease.ATCs are resistant to standard therapies and are extremely difficult to manage.The stepwise cell dedifferentiation results in the impairment of the iodine-metabolizing machinery and the infeasibility of radioiodine treatment in ATC.Hence,reinducing iodine-metabolizing gene expression to restore radioiodine avidity is considered as a promising strategy to fight against ATC.In the present study,capsaicin(CAP),a natural potent transient receptor potential vanilloid type 1(TRPV1)agonist,was discovered to reinduce ATC cell differentiation and to increase the expression of thyroid transcription factors(TTFs including TTF-1,TTF-2,and PAX8)and iodine-metabolizing proteins,including thyroidstimulating hormone receptor(TSHR),thyroid peroxidase,and sodium iodine symporter(NIS),in two ATC cell lines,8505C and FRO.Strikingly,CAP treatment promoted NIS glycosylation and its membrane trafficking,resulting in a significant enhancement of radioiodine uptake of ATC cells in vitro.Mechanistically,CAP-activated TRPV1 channel and subsequently triggered Ca2þinflux,cyclic adenosine monophosphate(cAMP)generation,and cAMP-responsive element-binding protein(CREB)signal activation.Next,CREB recognized and bound to the promoter of SLC5A5 to facilitate its transcription.Moreover,the TRPV1 antagonist CPZ,the calcium chelator BAPTA,and the PKA inhibitor H-89 effectively alleviated the redifferentiation exerted by CAP,demonstrating that CAP might improve radioiodine avidity through the activation of the TRPV1–Ca2þ/cAMP/PKA/CREB signaling pathway.In addition,our study indicated that CAP might trigger a novel cascade to redifferentiate ATC cells and provide unprecedented opportunities for radioiodine therapy in ATC,bypassing canonical TSH–TSHR pathway.展开更多
文摘Background: Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in Western societies and are rapidly becoming a worldwide health problem. African-Americans have increased morbidity and mortality rates from CVD. Our study aimed to assess the effects of the CVD risk factors burden alone versus with diabetes mellitus in a high riskCVDpopulation. Methods: The two study groups consisted of thirty seven diabetics and thirty seven non-diabetic African-Americans aged ≥55 years without clinical atherosclerosis having similar cardiovascular risk factors (age, hypertension, hypercholesterolemia, smoking, and body mass index) except for diabetes mellitus. Brachial artery flow-mediated dilation (FMD), Nitroglycerin-mediated dilatation (NMD) and carotid intima-media thickness (IMT) were recorded in all subjects. Results: Endothelial function as assessed by the brachial artery FMD was significantly impaired in the diabetic group compared to the non-diabetic group (7.8 ± 5 vs 3.3 ± 4;p = 0.0001). There were no differences in neither Nitroglycerin-mediated dilatation (NMD) nor carotid intima-media thickness (IMT) in the diabetic and non-diabetic groups. Conclusion: The contribution of diabetes to the development of endothelial dysfunction in subjects with clustering of CVD risk factors may be early as indicated by significant functional changes preceeding structural vascular changes..
基金supported by the National Key Basic Research Program of China(No.2016YFA0200103)the National Natural Science Foundation of China(Nos.51520105003,51432002,and U1904193)+2 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXTD-202001)Beijing Municipal Science&Technology Commission(Nos.Z201100008720006,Z181100004818001,and Z191100000819007)Beijing Nova Program of Science and Technology(No.Z191100001119067).
文摘Cu wires(CuWs)are widely used as electric transmission lines.However,their limited thermal and chemical stabilities become challenges under the high-power and harsh environment.Graphene is regarded as an ideal protective barrier for CuW benefiting from its impermeability to all atoms and molecules.Particularly,the excellent hydrophobicity of vertical graphene(VG)will strengthen its protective capability as a corrosion and oxidation barrier.Herein,VG is directly synthesized on CuW by plasmaenhanced chemical vapor deposition method.The hydrophobic VG coating with a high water contact angle can effectively exclude the corrosive liquid and moisture from CuW surface and prevent their further penetration.Consequently,the electrochemical corrosion rate of VG-CuW is reduced by~13,8,and 2 times,compared with bare CuW,VG-CuW with hydrophilic treatment,and CuW coated with thick horizontal graphene layers,respectively.Negligible oxidation occurs on VGCuW after the long-time exposure to humid air at~200℃ along with the largely enhanced tolerance under high-current operating condition.This study reveals the impressive potentials of hydrophobic VG as a robust corrosion and oxidation barrier for metal wires used in high-power cables and electronic devices in harsh environment.
基金financially supported by the National Natural Science Foundation of China(Nos.52272032,T2188101,and 52021006)the Beijing Nova Program of Science and Technology(No.20220484079).
文摘With the continuous advancements in electronics towards downsizing and integration,efficient thermal dissipation from chips has emerged as a critical factor affecting their lifespan and operational efficiency.The fan-less chip cooling system has two critical interfaces for thermal transport,which are the contact interface between the base and the chip dominated by thermal conduction,and the surface of the fins dominated by thermal radiation.The different thermal transfer modes of these two critical interfaces pose different requirements for thermal management materials.In the study,a novel approach was proposed by developing graphene thermal transport functional material whose morphology could be intentionally designed via reformed plasmaenhanced chemical vapor deposition(PECVD)methods to meet the diverse requirements of heat transfer properties.Specifically,graphene with multilevel branching structure of vertical graphene(BVG)was fabricated through the hydrogenassisted PECVD(H_(2)-PECVD)strategy,which contributed a high emissivity of~0.98.BVG was deposited on the fins’surface and functioned as the radiation enhanced layer to facilitate the rapid radiation of heat from the heat sinks into the surrounding air.Meanwhile,the well-oriented vertical graphene(OVG)was successfully prepared through the vertical electric field-assisted PECVD process(EF-PECVD),which showed a high directional thermal conductivity of~53.5 W·m^(-1)·K^(-1).OVG was deposited on the contact interface and functioned as the thermal conduction enhanced layer,allowing for the quick transmission of heat from the chip to the heat sink.Utilizing this design concept,the two critical interfaces in the chip cooling system can be jointly enhanced,resulting in a remarkable cooling efficiency enhancement of~30.7%,demonstrating that this novel material possessed enormous potential for enhancing the performance of cooling systems.Therefore,this research not only provided new design concepts for the cooling system of electronic devices but also opened up new avenues for the application of graphene materials in thermal management.
基金supported by grants from the National Natural Science Foundation of China(81972503 and 82103656).
文摘Anaplastic thyroid cancer(ATC)is a rare but highly lethal disease.ATCs are resistant to standard therapies and are extremely difficult to manage.The stepwise cell dedifferentiation results in the impairment of the iodine-metabolizing machinery and the infeasibility of radioiodine treatment in ATC.Hence,reinducing iodine-metabolizing gene expression to restore radioiodine avidity is considered as a promising strategy to fight against ATC.In the present study,capsaicin(CAP),a natural potent transient receptor potential vanilloid type 1(TRPV1)agonist,was discovered to reinduce ATC cell differentiation and to increase the expression of thyroid transcription factors(TTFs including TTF-1,TTF-2,and PAX8)and iodine-metabolizing proteins,including thyroidstimulating hormone receptor(TSHR),thyroid peroxidase,and sodium iodine symporter(NIS),in two ATC cell lines,8505C and FRO.Strikingly,CAP treatment promoted NIS glycosylation and its membrane trafficking,resulting in a significant enhancement of radioiodine uptake of ATC cells in vitro.Mechanistically,CAP-activated TRPV1 channel and subsequently triggered Ca2þinflux,cyclic adenosine monophosphate(cAMP)generation,and cAMP-responsive element-binding protein(CREB)signal activation.Next,CREB recognized and bound to the promoter of SLC5A5 to facilitate its transcription.Moreover,the TRPV1 antagonist CPZ,the calcium chelator BAPTA,and the PKA inhibitor H-89 effectively alleviated the redifferentiation exerted by CAP,demonstrating that CAP might improve radioiodine avidity through the activation of the TRPV1–Ca2þ/cAMP/PKA/CREB signaling pathway.In addition,our study indicated that CAP might trigger a novel cascade to redifferentiate ATC cells and provide unprecedented opportunities for radioiodine therapy in ATC,bypassing canonical TSH–TSHR pathway.
