Summer phytoplankton blooms appear frequently off the Somali coast in the southwestern Arabian Sea(AS),where strong reversal monsoon and summer upwelling is prevailing.Distinct high chlorophyll-a(Chla)concentrations i...Summer phytoplankton blooms appear frequently off the Somali coast in the southwestern Arabian Sea(AS),where strong reversal monsoon and summer upwelling is prevailing.Distinct high chlorophyll-a(Chla)concentrations in summer were displayed in the western AS,especially in the region off the Somali coast.The spatial and inter-annual variations of the summer high Chla were studied using satellite data including ocean color and wind vectors.Under ocean conditions including monsoon winds,Ekman transport(ET)and Ekman pumping velocity(EPV),as well as geostrophic current and aerosol precipitation,the possible mechanisms of high Chl-a was investigated.The summer high Chl-a presented strong inter-annual variations in the southwestern AS.The results of simple correlation analysis indicated that there were good correlations between the ET and Chl-a,as well as between EPV and Chl-a.These implied that the ET and EPV may cause uplift of nutrients into the upper layer of the western AS from subsurface or coastal regions,inducing high Chl-a in the southwestern AS,especially in the region off the Somali coasts in summer.The multiple/partial correlation analysis implied further that EPV-induced upwelling may be more helpful than the ETinduced upwelling in the coastal region off Somalia,leading to probably more significant influence of EPV upwelling on the phytoplankton bloom than upwelling by ET.Aerosol precipitation in the southwestern AS also played an important role in high Chl-a in the deep offshore AS(i.e.,Section B in Fig.1(a)),as second only to ET and sea surface temperature(SST),and even higher than EPV.A novel finding is that the influence of aerosol optical thickness(AOT)is evident in the offshore region and the dust precipitation is more important sources to oligotrophic water.Both the stability of the upper ocean and the aerosol precipitation may play more evident roles in the open regions of the southwestern AS off Somali.展开更多
Gelatin-based biomaterials have emerged as promising candidates for bioadhesives due to their biodegradability and biocompatibility.However,they often face limitations due to the uncontrollable phase transition of gel...Gelatin-based biomaterials have emerged as promising candidates for bioadhesives due to their biodegradability and biocompatibility.However,they often face limitations due to the uncontrollable phase transition of gelatin,which is dominated by hydrogen bonds between peptide chains.Here,we developed controllable phase transition gelatin-based(CPTG)bioadhesives by regulating the dynamic balance of hydrogen bonds between the peptide chains using 2-hydroxyethylurea(HU)and punicalagin(PA).These CPTG bioadhesives exhibited significant enhancements in adhesion energy and injectability even at 4℃compared to traditional gelatin bioadhesives.The developed bioadhesives could achieve self-reinforcing interfacial adhesion upon contact with moist wound tissues.This effect was attributed to HU diffusion,which disrupted the dynamic balance of hydrogen bonds and therefore induced a localized structural densification.This process was further facilitated by the presence of pyrogallol from PA.Furthermore,the CPTG bioadhesive could modulate the immune microenvironment,offering antibacterial,antioxidant,and immune-adjustable properties,thereby accelerating diabetic wound healing,as confirmed in a diabetic wound rat model.This proposed design strategy is not only crucial for developing controllable phase-transition bioadhesives for diverse applications,but also paves the way for broadening the potential applications of gelatin-based biomaterials.展开更多
A recent study published in Nature Communications showed that essential modulatory roles of interfacial adhesion and mechanical microenvironments such as geometric constraints and extracellular matrix stiffness,in mic...A recent study published in Nature Communications showed that essential modulatory roles of interfacial adhesion and mechanical microenvironments such as geometric constraints and extracellular matrix stiffness,in microbehost cell interactions.This study utilized single-cell force spectroscopy and RNA sequencing to gain insight into the intrinsic mechanisms by which the mechanical microenvironment regulates bacterial-host interactions and therefore reveal potential interventions against bacterial invasion.Meanwhile,the adhesion forces involved in the bacterial–host interactions were recognized as a new indicator for assessing the extent of bacterial infection.Taken together,these findings demonstrate that interfacial adhesion forces and mechanical microenvironments play a dominant role in modulating functions and behaviors of microorganisms and host cells,which also provide a mechanobiology-inspired idea for the development of subsequent drug-resistant antimicrobials and broadspectrum antiviral drugs.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42076162)the Natural Science Foundation of Guangdong Province,China(No.2020A1515010496)supported by Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.311020004).
文摘Summer phytoplankton blooms appear frequently off the Somali coast in the southwestern Arabian Sea(AS),where strong reversal monsoon and summer upwelling is prevailing.Distinct high chlorophyll-a(Chla)concentrations in summer were displayed in the western AS,especially in the region off the Somali coast.The spatial and inter-annual variations of the summer high Chla were studied using satellite data including ocean color and wind vectors.Under ocean conditions including monsoon winds,Ekman transport(ET)and Ekman pumping velocity(EPV),as well as geostrophic current and aerosol precipitation,the possible mechanisms of high Chl-a was investigated.The summer high Chl-a presented strong inter-annual variations in the southwestern AS.The results of simple correlation analysis indicated that there were good correlations between the ET and Chl-a,as well as between EPV and Chl-a.These implied that the ET and EPV may cause uplift of nutrients into the upper layer of the western AS from subsurface or coastal regions,inducing high Chl-a in the southwestern AS,especially in the region off the Somali coasts in summer.The multiple/partial correlation analysis implied further that EPV-induced upwelling may be more helpful than the ETinduced upwelling in the coastal region off Somalia,leading to probably more significant influence of EPV upwelling on the phytoplankton bloom than upwelling by ET.Aerosol precipitation in the southwestern AS also played an important role in high Chl-a in the deep offshore AS(i.e.,Section B in Fig.1(a)),as second only to ET and sea surface temperature(SST),and even higher than EPV.A novel finding is that the influence of aerosol optical thickness(AOT)is evident in the offshore region and the dust precipitation is more important sources to oligotrophic water.Both the stability of the upper ocean and the aerosol precipitation may play more evident roles in the open regions of the southwestern AS off Somali.
基金supported by National Key Research and Development Program of China(grant nos.2021YFA1000200 and 2021YFA1000201)National Natural Science Foundation of China(grant nos.12372175,12102010 and 52363019)+1 种基金Tianjin Municipal Science and Technology Plan Project(grant no.24ZYCGSY00650)Tianjin Health Technology Project(grant no.TJWJ2022XK043).
文摘Gelatin-based biomaterials have emerged as promising candidates for bioadhesives due to their biodegradability and biocompatibility.However,they often face limitations due to the uncontrollable phase transition of gelatin,which is dominated by hydrogen bonds between peptide chains.Here,we developed controllable phase transition gelatin-based(CPTG)bioadhesives by regulating the dynamic balance of hydrogen bonds between the peptide chains using 2-hydroxyethylurea(HU)and punicalagin(PA).These CPTG bioadhesives exhibited significant enhancements in adhesion energy and injectability even at 4℃compared to traditional gelatin bioadhesives.The developed bioadhesives could achieve self-reinforcing interfacial adhesion upon contact with moist wound tissues.This effect was attributed to HU diffusion,which disrupted the dynamic balance of hydrogen bonds and therefore induced a localized structural densification.This process was further facilitated by the presence of pyrogallol from PA.Furthermore,the CPTG bioadhesive could modulate the immune microenvironment,offering antibacterial,antioxidant,and immune-adjustable properties,thereby accelerating diabetic wound healing,as confirmed in a diabetic wound rat model.This proposed design strategy is not only crucial for developing controllable phase-transition bioadhesives for diverse applications,but also paves the way for broadening the potential applications of gelatin-based biomaterials.
基金supported by National Natural Science Foundation of China(Grant no.12372175).
文摘A recent study published in Nature Communications showed that essential modulatory roles of interfacial adhesion and mechanical microenvironments such as geometric constraints and extracellular matrix stiffness,in microbehost cell interactions.This study utilized single-cell force spectroscopy and RNA sequencing to gain insight into the intrinsic mechanisms by which the mechanical microenvironment regulates bacterial-host interactions and therefore reveal potential interventions against bacterial invasion.Meanwhile,the adhesion forces involved in the bacterial–host interactions were recognized as a new indicator for assessing the extent of bacterial infection.Taken together,these findings demonstrate that interfacial adhesion forces and mechanical microenvironments play a dominant role in modulating functions and behaviors of microorganisms and host cells,which also provide a mechanobiology-inspired idea for the development of subsequent drug-resistant antimicrobials and broadspectrum antiviral drugs.
