The aim was to investigate the effect of three water levels (umbilical, 4</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;&...The aim was to investigate the effect of three water levels (umbilical, 4</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;"> rib, and clavicular) on the respiratory function and respiratory muscle strength among elderly. Spirometry and respiratory strength were measured on land as baseline data. Next, water depth conditions were determined randomly, and spirometry and respiratory muscle strength were measured at each water level. The Vital Capacity and Expiratory reserve volume in the clavicular level were significantly lower than those in the land and umbilical trials. No significant difference was observed in other respiratory functions. Chest circumference and respiratory muscle strength were not significantly different among all conditions.展开更多
In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts f...In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.展开更多
Land creation projects have been implemented in China to expand urban space in mountainous areas.In addition to the predictable settlement brought about by filling construction,varying degrees of land subsidence and e...Land creation projects have been implemented in China to expand urban space in mountainous areas.In addition to the predictable settlement brought about by filling construction,varying degrees of land subsidence and engineering failures have a demonstrated relationship to groundwater level fluctuation induced by land creation engineering.In this work,we adopted a typical large-scale land creation project,Yan’an New City in Shaanxi province,West China,as our study area.Prior to conducting the main experiment,preliminary field investigation and groundwater level monitoring were conducted to determine the groundwater fluctuation trend induced by land creation engineering.Although a blind drainage system was implemented,the depth aspect of groundwater level changes after large-scale land creation still needed to be addressed.To study the degree of impact and the settlement mechanism induced by the rising groundwater level,we conducted a Water Immersion Test(WIT)in a typical land creation site for 107 days.The rising groundwater level was simulated by injecting water from the bottom of the filling foundation.During the WIT,the soil water content,surface subsidence,and internal settlement of soil at different depths were obtained.Surface subsidence development could be categorized into four stages during the water level increase.The second stage,which is defined as the point when the groundwater level rises to 10 m,marked the critical point in the process.Furthermore,it was ascertained that the local settlement in regions that were originally composed of steep slopes is larger than that in originally flat areas.In addition,ground cracks and sinkholes in the study area were inspected;and it was determined that they would become new channels that would accelerate water infiltration and exacerbate the settlement.Based on the results from our field investigation and testing,several suggestions are proposed for land creation projects to mitigate issues associated with construction-induced groundwater level rising.展开更多
During endoscopy,an endoscopist is inevitably faced with the occasional“difficult colonoscopy,”in which the endoscopist finds it challenging to advance the endoscope to the cecum.Beyond optimization of technique,wit...During endoscopy,an endoscopist is inevitably faced with the occasional“difficult colonoscopy,”in which the endoscopist finds it challenging to advance the endoscope to the cecum.Beyond optimization of technique,with minimized looping,minimal insufflation,sufficient sedation,and abdominal splinting when needed,sometimes additional tools may be needed.In this review,we cover available techniques and technologies to help navigate the difficult colonoscopy,including the ultrathin colonoscope,rigidizing overtube,balloon-assisted colonoscopy and the abdominal compression device.展开更多
The produced water from the oilfield was purified with filter material and then injected back into the ground.The serpentine filter material was easy to harden with the increase in filtration amount,which affected the...The produced water from the oilfield was purified with filter material and then injected back into the ground.The serpentine filter material was easy to harden with the increase in filtration amount,which affected the water quality.A superhydrophilic/underwater oleophobic serpentine filter material was successfully prepared by a simple method of coating modification,which exhibited long-lasting filtration of oily water,good filtration and anti-fouling properties,and resistance to harden.The film-forming material of the superhydrophilic/underwater oleophobic coating was composed of SiO_(2) particles with small size,which could completely and evenly cover the filter particle.The weight loss was only 7.6%after mechanical stirring for 90 min.Compared with the original filter material,the superhydrophilic/underwater oleophobic serpentine filter material showed a better anti-fouling ability and resistance to harden.The filtration of crude oil emulsion and oil slick sewage showed a better backwashing performance.After 35 cycles of continuous filtration of suspended solids in wastewater,the backwashing rate reached 78.4%.The results provided an effective method for the filtration of oily wastewater in the oilfield.展开更多
BACKGROUND Stress-related gastric mucosal damage or ulcer remains an unsolved issue for critically ill patients.Stress ulcer prophylaxis has been part of routine intensive care,but uncertainty and controversy still ex...BACKGROUND Stress-related gastric mucosal damage or ulcer remains an unsolved issue for critically ill patients.Stress ulcer prophylaxis has been part of routine intensive care,but uncertainty and controversy still exist.Co-secreted with mucins,intestinal trefoil factor(ITF)is reported to promote restitution and regeneration of intestinal mucosal epithelium,although the mechanism remains unknown.AIM To elucidate the protective effects of ITF on gastric mucosa and explore the possible mechanisms.METHODS We used a rat model of gastric mucosal damage induced by water immersion restraint stress and lipopolysaccharide-treated human gastric epithelial cell line to investigate the potential effects of ITF on damaged gastric mucosa both in vivo and in vitro.RESULTS ITF promoted the proliferation and migration and inhibited necrosis of gastric mucosal epithelia in vitro.It also preserved the integrity of gastric mucosa by upregulating expressions of occludin and zonula occludens-1.In the rat model,pretreatment with ITF ameliorated the gastric mucosal epithelial damage and facilitated mucosal repair.The protective effects of ITF were confirmed to be exerted via activation of Akt signaling,and the specific inhibitor of Akt signaling LY249002 reversed the protective effects.CONCLUSION ITF might be a promising candidate for prevention and treatment of stressinduced gastric mucosal damage,and further studies should be undertaken to verify its clinical feasibility.展开更多
There is some discussion as to whether exercise-induced hyperthermia of the superficial digital flexor tendon (SDFT) affects tenocyte viability and pre-disposes to injury. Cold-therapy is commonly used as a preventati...There is some discussion as to whether exercise-induced hyperthermia of the superficial digital flexor tendon (SDFT) affects tenocyte viability and pre-disposes to injury. Cold-therapy is commonly used as a preventative measure and treatment for acute tendon injuries, but only a few studies have evaluated the effect of cold-therapy on metacarpal temperatures in the horse. For this reason, this study has measured skin surface temperatures after moderate exercise and after application of cold-therapy, and additionally monitored the duration of any effects. Four horses were recruited into a semi blinded controlled study with repeated measurements that involved lunged exercise for 16 minutes at moderate intensity. Skin surface temperature was measured using a thermographic camera before and after lunging, and every 40 minutes for two hours post cold-therapy. Cold-therapy was applied using a Jacks Whirlpool Boot with ice-water immersion at a level just distal to the carpus for 20 minutes. The right leg was treated, and the left leg was used as an untreated control. The experiment was conducted twice on all four horses. Moderate exercise resulted in an increase in skin surface temperature of 10<sup>°</sup>C. Application of cold-therapy for 20 minutes resulted in a reduction in skin surface temperature by 14<sup>°</sup>C. The effect of cold-therapy persisted for at least 40 minutes post treatment. It is concluded that exercise leads to an increase in skin surface temperature which is counteracted by the application of cold-therapy. These findings would seem to indicate that cold-therapy can be used after exercise to counteract hyperthermia within the metacarpal region of the horse’s leg.展开更多
Objective: Rosa odorata var. gigantea is a popular medicinal plant. Some studies have demonstrated that ethanolic extract of the fruits of R. odorata var. gigantea(FOE) has gastroprotective properties. The aim of this...Objective: Rosa odorata var. gigantea is a popular medicinal plant. Some studies have demonstrated that ethanolic extract of the fruits of R. odorata var. gigantea(FOE) has gastroprotective properties. The aim of this study was to investigate the gastroprotective activity of FOE on water immersion restrained stress(WIRS)-induced gastric mucosal injury in a rat model and elucidate the possible molecular mechanisms involved.Methods: A rat stress ulcer model was established in this study using WIRS. After rats were treated with FOE orally for 7 d, the effect of FOE treatment was analyzed by hematoxylin and eosin(H&E) staining, and the changes of inflammatory factors, oxidative stress factors, and gastric-specific regulatory factors and pepsin in the blood and gastric tissues of rats were examined by ELISA assay. Molecular mechanism of FOE was investigated by immunohistochemical assay and Western blot.Results: Compared with the WIRS group, FOE could diminish both the macroscopic and microscopic pathological morphology of gastric mucosa. FOE significantly preserved the antioxidants glutathione peroxidase(GSH-PX), superoxide dismutase(SOD) and catalase(CAT) contents;anti-inflammatory cytokines interleukin-10(IL-10) and prostaglandin E2(PGE2) levels as well as regulatory factors tumor necrosis factor-a(TGF-a) and somatostatin(SS) contents, while decreasing malondialdehyde(MDA), nitric oxide synthase(i NOS), tumor necrosis factor(TNF-a), interleukin-1β(IL-1β), interleukin-6(IL-6), gastrin(GAS)and endothelin(ET) levels. Moreover, FOE distinctly upregulated the expression of Nrf2, HO-1, Bcl2 and proliferating cell nuclear antigen(PCNA). In addition, FOE activated the expression of p-EGFR and downregulated the expression of NF-ΚB, Bax, Cleaved-caspase-3, Cyto-C and Cleaved-PARP1, thus promoting gastric mucosal cell survival.Conclusion: The current work demonstrated that FOE exerted a gastroprotective activity against gastric mucosal injury induced by WIRS. The underlying mechanism might be associated with the improvement of anti-inflammatory, anti-oxidation and anti-apoptosis systems.展开更多
The hydrokinetic energy of river current,as one of the essential and widespread renewable energies,is difficult to be harvested in low flow velocity and shallow water areas.In this work,a three-dimensional(3D)fully-en...The hydrokinetic energy of river current,as one of the essential and widespread renewable energies,is difficult to be harvested in low flow velocity and shallow water areas.In this work,a three-dimensional(3D)fully-enclosed triboelectric nanogenerator(FETENG)with bionic fish-like structure for harvesting hydrokinetic energy is reported,which is comprised of the triboelectric powergeneration unit,bionic fish-like structure and connection unit.Through the bionic structure,the FE-TENG realizes zero head power generation in shallow water with low flow velocity.What’s more,the effect of external excitations and bionic structures on the electrical performance are systematically studied in this work.The FE-TENG can generate peak power density of 7 and 0.36 W/m^(3)respectively under the simulated swing state with frequency of 1.25 Hz and simulated river current with flow velocity of 0.81 m/s.In practical applications,due to the 3D fully-enclosed design,the FE-TENG immersed in water for 35 days demonstrates excellent immersion durability with undiminished electrical performance.Therefore,the work proposes an efficient method realizing zero head power generation,and provides a good candidate for long-term service in the river current.展开更多
文摘The aim was to investigate the effect of three water levels (umbilical, 4</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;"> rib, and clavicular) on the respiratory function and respiratory muscle strength among elderly. Spirometry and respiratory strength were measured on land as baseline data. Next, water depth conditions were determined randomly, and spirometry and respiratory muscle strength were measured at each water level. The Vital Capacity and Expiratory reserve volume in the clavicular level were significantly lower than those in the land and umbilical trials. No significant difference was observed in other respiratory functions. Chest circumference and respiratory muscle strength were not significantly different among all conditions.
基金This work was supported by the Budgetary Project the Chinese Academy of Sciences Leads the Sub-Project of Class A Project(XDA26020202)the National“973”Program Project Topics(2014CB138702)+2 种基金the Basic Scientific Research Business Expenses of Central Universities(Lzujbky-2022-kb10)the 111 Wisdom Base(B12002)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Chinese Academy of Forestry)(CAFYBB2021ZD001).
文摘In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.
基金financial support from National Natural Science Foundation of China (Project No. 41902299 41672305)+2 种基金the Key Science and Technology Program of Shaanxi Province (Project No. 2017ZDXM-SF-078, 2017ZDXM-SF-082)National Key Research and Development Program of China (2018YFC1504700)Shaanxi new-star plan of science and technology (Project No. 2018KJXX020)
文摘Land creation projects have been implemented in China to expand urban space in mountainous areas.In addition to the predictable settlement brought about by filling construction,varying degrees of land subsidence and engineering failures have a demonstrated relationship to groundwater level fluctuation induced by land creation engineering.In this work,we adopted a typical large-scale land creation project,Yan’an New City in Shaanxi province,West China,as our study area.Prior to conducting the main experiment,preliminary field investigation and groundwater level monitoring were conducted to determine the groundwater fluctuation trend induced by land creation engineering.Although a blind drainage system was implemented,the depth aspect of groundwater level changes after large-scale land creation still needed to be addressed.To study the degree of impact and the settlement mechanism induced by the rising groundwater level,we conducted a Water Immersion Test(WIT)in a typical land creation site for 107 days.The rising groundwater level was simulated by injecting water from the bottom of the filling foundation.During the WIT,the soil water content,surface subsidence,and internal settlement of soil at different depths were obtained.Surface subsidence development could be categorized into four stages during the water level increase.The second stage,which is defined as the point when the groundwater level rises to 10 m,marked the critical point in the process.Furthermore,it was ascertained that the local settlement in regions that were originally composed of steep slopes is larger than that in originally flat areas.In addition,ground cracks and sinkholes in the study area were inspected;and it was determined that they would become new channels that would accelerate water infiltration and exacerbate the settlement.Based on the results from our field investigation and testing,several suggestions are proposed for land creation projects to mitigate issues associated with construction-induced groundwater level rising.
文摘During endoscopy,an endoscopist is inevitably faced with the occasional“difficult colonoscopy,”in which the endoscopist finds it challenging to advance the endoscope to the cecum.Beyond optimization of technique,with minimized looping,minimal insufflation,sufficient sedation,and abdominal splinting when needed,sometimes additional tools may be needed.In this review,we cover available techniques and technologies to help navigate the difficult colonoscopy,including the ultrathin colonoscope,rigidizing overtube,balloon-assisted colonoscopy and the abdominal compression device.
基金The National Natural Science Foundation of China(No.52071076)Opening Project of State Key Laboratory of Advanced Technology for Float Glass(Grant 2022KF03)are gratefully acknowledged.
文摘The produced water from the oilfield was purified with filter material and then injected back into the ground.The serpentine filter material was easy to harden with the increase in filtration amount,which affected the water quality.A superhydrophilic/underwater oleophobic serpentine filter material was successfully prepared by a simple method of coating modification,which exhibited long-lasting filtration of oily water,good filtration and anti-fouling properties,and resistance to harden.The film-forming material of the superhydrophilic/underwater oleophobic coating was composed of SiO_(2) particles with small size,which could completely and evenly cover the filter particle.The weight loss was only 7.6%after mechanical stirring for 90 min.Compared with the original filter material,the superhydrophilic/underwater oleophobic serpentine filter material showed a better anti-fouling ability and resistance to harden.The filtration of crude oil emulsion and oil slick sewage showed a better backwashing performance.After 35 cycles of continuous filtration of suspended solids in wastewater,the backwashing rate reached 78.4%.The results provided an effective method for the filtration of oily wastewater in the oilfield.
基金Social Development Projects of Jiangsu Province,No.BE2017720the National Natural Science Foundation of China,No.81701894+4 种基金Jiangsu Provincial Medical Youth Talent,No.QNRC2016909 and No.QNRC2016908Natural Science Foundation of Jiangsu Province,No.BK20190247Science Foundation of Jiangsu Health Commission,No.H2018039China Postdoctoral Science Foundation,No.2018M643890Jiangsu Postdoctoral Science Foundation,No.2018K048A and No.2020Z193。
文摘BACKGROUND Stress-related gastric mucosal damage or ulcer remains an unsolved issue for critically ill patients.Stress ulcer prophylaxis has been part of routine intensive care,but uncertainty and controversy still exist.Co-secreted with mucins,intestinal trefoil factor(ITF)is reported to promote restitution and regeneration of intestinal mucosal epithelium,although the mechanism remains unknown.AIM To elucidate the protective effects of ITF on gastric mucosa and explore the possible mechanisms.METHODS We used a rat model of gastric mucosal damage induced by water immersion restraint stress and lipopolysaccharide-treated human gastric epithelial cell line to investigate the potential effects of ITF on damaged gastric mucosa both in vivo and in vitro.RESULTS ITF promoted the proliferation and migration and inhibited necrosis of gastric mucosal epithelia in vitro.It also preserved the integrity of gastric mucosa by upregulating expressions of occludin and zonula occludens-1.In the rat model,pretreatment with ITF ameliorated the gastric mucosal epithelial damage and facilitated mucosal repair.The protective effects of ITF were confirmed to be exerted via activation of Akt signaling,and the specific inhibitor of Akt signaling LY249002 reversed the protective effects.CONCLUSION ITF might be a promising candidate for prevention and treatment of stressinduced gastric mucosal damage,and further studies should be undertaken to verify its clinical feasibility.
文摘There is some discussion as to whether exercise-induced hyperthermia of the superficial digital flexor tendon (SDFT) affects tenocyte viability and pre-disposes to injury. Cold-therapy is commonly used as a preventative measure and treatment for acute tendon injuries, but only a few studies have evaluated the effect of cold-therapy on metacarpal temperatures in the horse. For this reason, this study has measured skin surface temperatures after moderate exercise and after application of cold-therapy, and additionally monitored the duration of any effects. Four horses were recruited into a semi blinded controlled study with repeated measurements that involved lunged exercise for 16 minutes at moderate intensity. Skin surface temperature was measured using a thermographic camera before and after lunging, and every 40 minutes for two hours post cold-therapy. Cold-therapy was applied using a Jacks Whirlpool Boot with ice-water immersion at a level just distal to the carpus for 20 minutes. The right leg was treated, and the left leg was used as an untreated control. The experiment was conducted twice on all four horses. Moderate exercise resulted in an increase in skin surface temperature of 10<sup>°</sup>C. Application of cold-therapy for 20 minutes resulted in a reduction in skin surface temperature by 14<sup>°</sup>C. The effect of cold-therapy persisted for at least 40 minutes post treatment. It is concluded that exercise leads to an increase in skin surface temperature which is counteracted by the application of cold-therapy. These findings would seem to indicate that cold-therapy can be used after exercise to counteract hyperthermia within the metacarpal region of the horse’s leg.
基金supported by the National Natural Science Foundation of China(No.81673693)the National Key R&D Program of China(No.2017YFD0201402)for financial support.
文摘Objective: Rosa odorata var. gigantea is a popular medicinal plant. Some studies have demonstrated that ethanolic extract of the fruits of R. odorata var. gigantea(FOE) has gastroprotective properties. The aim of this study was to investigate the gastroprotective activity of FOE on water immersion restrained stress(WIRS)-induced gastric mucosal injury in a rat model and elucidate the possible molecular mechanisms involved.Methods: A rat stress ulcer model was established in this study using WIRS. After rats were treated with FOE orally for 7 d, the effect of FOE treatment was analyzed by hematoxylin and eosin(H&E) staining, and the changes of inflammatory factors, oxidative stress factors, and gastric-specific regulatory factors and pepsin in the blood and gastric tissues of rats were examined by ELISA assay. Molecular mechanism of FOE was investigated by immunohistochemical assay and Western blot.Results: Compared with the WIRS group, FOE could diminish both the macroscopic and microscopic pathological morphology of gastric mucosa. FOE significantly preserved the antioxidants glutathione peroxidase(GSH-PX), superoxide dismutase(SOD) and catalase(CAT) contents;anti-inflammatory cytokines interleukin-10(IL-10) and prostaglandin E2(PGE2) levels as well as regulatory factors tumor necrosis factor-a(TGF-a) and somatostatin(SS) contents, while decreasing malondialdehyde(MDA), nitric oxide synthase(i NOS), tumor necrosis factor(TNF-a), interleukin-1β(IL-1β), interleukin-6(IL-6), gastrin(GAS)and endothelin(ET) levels. Moreover, FOE distinctly upregulated the expression of Nrf2, HO-1, Bcl2 and proliferating cell nuclear antigen(PCNA). In addition, FOE activated the expression of p-EGFR and downregulated the expression of NF-ΚB, Bax, Cleaved-caspase-3, Cyto-C and Cleaved-PARP1, thus promoting gastric mucosal cell survival.Conclusion: The current work demonstrated that FOE exerted a gastroprotective activity against gastric mucosal injury induced by WIRS. The underlying mechanism might be associated with the improvement of anti-inflammatory, anti-oxidation and anti-apoptosis systems.
基金the support received from the National Key R&D Project from the Minister of Science and Technology(Nos.2021YFA1201601 and 2021YFA1201604)the Natural Science Foundation of Beijing Municipality(No.3222023)。
文摘The hydrokinetic energy of river current,as one of the essential and widespread renewable energies,is difficult to be harvested in low flow velocity and shallow water areas.In this work,a three-dimensional(3D)fully-enclosed triboelectric nanogenerator(FETENG)with bionic fish-like structure for harvesting hydrokinetic energy is reported,which is comprised of the triboelectric powergeneration unit,bionic fish-like structure and connection unit.Through the bionic structure,the FE-TENG realizes zero head power generation in shallow water with low flow velocity.What’s more,the effect of external excitations and bionic structures on the electrical performance are systematically studied in this work.The FE-TENG can generate peak power density of 7 and 0.36 W/m^(3)respectively under the simulated swing state with frequency of 1.25 Hz and simulated river current with flow velocity of 0.81 m/s.In practical applications,due to the 3D fully-enclosed design,the FE-TENG immersed in water for 35 days demonstrates excellent immersion durability with undiminished electrical performance.Therefore,the work proposes an efficient method realizing zero head power generation,and provides a good candidate for long-term service in the river current.