Prostate cancer is a common male malignant tumor,and bone metastasis is one of the common complications in the late stage of prostate cancer.The mechanism of prostate cancer bone metastasis is a complex process involv...Prostate cancer is a common male malignant tumor,and bone metastasis is one of the common complications in the late stage of prostate cancer.The mechanism of prostate cancer bone metastasis is a complex process involving multiple factors and steps.In recent years,with in-depth research on the mechanism of prostate cancer bone metastasis and the development of new drugs,important progress has been made in the treatment of prostate cancer bone metastasis.Based on this,this article introduces the mechanism of prostate cancer bone metastasis and the research progress of several bone-targeted drugs to provide reference and inspiration for future research.展开更多
Due to the increasing demand for modified polylactide(PLA)meeting“double green”criteria,the research on sustainable plasticizers for PLA has attracted broad attentions.This study reported an open-ring polymerization...Due to the increasing demand for modified polylactide(PLA)meeting“double green”criteria,the research on sustainable plasticizers for PLA has attracted broad attentions.This study reported an open-ring polymerization method to fabricate cellulose(MCC)-g-PCL(poly(ε-caprolactone))copolymers with a fully sustainable and biodegradable component.MCC-g-PCL copolymers were synthesized,characterized,and used as green plasticizers for the PLA toughening.The results indicated that the MCC-g-PCL derivatives play an important role in the compatibility,crystallization,and toughening of the PLA/MCC-g-PCL composites.The mechanical properties of the fully bio-based PLA/MCC-g-PCL composites were optimized by adding 15 wt%MCC-g-PCL,that is,the elongation at break was 22.6%(~376%higher than that of neat PLA),the tensile strength was 47.3 MPa(comparable to that of neat PLA),and the impact strength was 26 J/m(~130%higher than that of neat PLA).DSC results indicated that MCC-g-PCL reduced the Tg of the PLA blend.When the addition amount was 15 wt%,the Tg of the blend was 58.4°C.Compared with MCC,MCC-g-PCL polyester plasticizer has better thermal stability,T5%(°C)can still be maintained above 300°C.The rheological results showed that MCC-g-PCL acted as a plasticizer,the introduction of PCL flexible chain increased the mobility of PLA molecular chain,and decreased the complex viscosity,storage modulus and loss modulus of PLA blends.The MCC-g-PCL derivatives,as a new green plastic additive,have shown an interesting prospect to prepare fully bio-based composites.展开更多
Achieving highly efficient extrication of the tunnel boring machine(TBM)cutter-head driving system from the collapsed surrounding rock has become a key problem globally,and significant effort has been directed to impr...Achieving highly efficient extrication of the tunnel boring machine(TBM)cutter-head driving system from the collapsed surrounding rock has become a key problem globally,and significant effort has been directed to improve TBM cutter-head extricating ability.In this study,the characteristics of a hydro-viscous device have been investigated to improve extricating performance of the TBM cutter-head.A numerical method based on an explicit pressure-linked equation is presented for computing the film parameters of the HVC,which is then applied to investigate extrication characteristics of a TBM cutter-head with a hydro-viscous clutch(HVC).The explicit pressure-linked equation is derived from the Navier–Stokes equations and the conservation equation,where boundary conditions are involved.The model of a cutter-head driving system with an HVC is established,and the extrication characteristics of the cutterhead driving system are analyzed and compared with three extrication strategies.The variation in extrication torque shows that the linear strategy or positive parabolic strategy are preferred for their relatively high extrication efficiency and low rigid impact,and the effects of throughflow rate on torque transmission are also investigated.The test rig of the TBM cutter-head driving system was set up to validate the numerical method and the model of a cutter-head driving system,and the feasibility of the proposed numerical method for researching the extrication of the TBM cutter-head is verified.展开更多
Phenolation is one of the effective strategies to synthesize lignin-based polyphenols,improve lignin’s properties,and extend its value-added applications in biological,medicinal and cosmetic fields.Herein,by taking t...Phenolation is one of the effective strategies to synthesize lignin-based polyphenols,improve lignin’s properties,and extend its value-added applications in biological,medicinal and cosmetic fields.Herein,by taking the structural feature advantage of lignin,an effective and green strategy was developed to molecularly engineer lignin into a robust lignin-3-(2-hydroxyphenyl)propionate ester(LPPE)derivative via a transesterification reaction between 3,4-dihydrocoumarin(DHC)and the aliphatic hydroxyls in lignin under organocatalysis.The strategy is optimized and the novel derivative was systematically characterized by ^(1)H,^(13)C and ^(31)P nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy.The findings indicated that the successful introduction of 3-(2-hydroxyphenyl)propionate groups using a OH groups/DHC/organic base mo-lar ratio of 1꞉1꞉0.3 at 120℃ for 6 h increased the content of phenolic hydroxyl groups from 1.7931 to 3.0179 mmol/g,and the LPPE exhibited excellent ultraviolet-absorbing and antioxidant per-formance with up to 90%free radical scavenging activity within 20 min using 5 mg/mL of LPPE.In addition,good biocompatibility and a high Sun protection factor(SPF)value of 40.9 were achieved at 5%(w)dosage of LPPE in the cream,indicating its significant application potential in sunscreen.展开更多
Meiosis is essential for evolution and genetic diversity in almost all sexual eukaryotic organisms.The mechanisms of meiotic recombination,such as synapsis,have been extensively investigated.However,it is still unclea...Meiosis is essential for evolution and genetic diversity in almost all sexual eukaryotic organisms.The mechanisms of meiotic recombination,such as synapsis,have been extensively investigated.However,it is still unclear whether signals from the cytoplasm or even from outside of the cell can regulate the meiosis process.Cilia are microtubule-based structures that protrude from the cell surface and function as signaling hubs to sense extracellular signals.Here,we reported an unexpected and critical role of cilia during meiotic recombination.During gametogenesis of zebrafish,cilia were specifically present in the prophase stages of both primary spermatocytes and primary oocytes.By developing a germ cell-specific CRISPR/Cas9 system,we demonstrated that germ cell-specific depletion of ciliary genes resulted in compromised double-strand break repair,reduced crossover formation,and increased germ cell apoptosis.Our study reveals a previously undiscovered role for cilia during meiosis and suggests that extracellular signals may regulate meiotic recombination via this particular organelle.展开更多
基金Traditional Chinese Medicine and Integrated Traditional Chinese and Western Medicine Research Project of Tianjin Municipal Administration of Traditional Chinese Medicine(2021106)Beijing-Tianjin-Hebei Traditional Chinese Medicine Collaborative Development Specialty Alliance Construction Project(First Teaching Hospital of Tianjin University of Traditional Chinese Medicine,Qingxian County Traditional Chinese Medicine Hospital).
文摘Prostate cancer is a common male malignant tumor,and bone metastasis is one of the common complications in the late stage of prostate cancer.The mechanism of prostate cancer bone metastasis is a complex process involving multiple factors and steps.In recent years,with in-depth research on the mechanism of prostate cancer bone metastasis and the development of new drugs,important progress has been made in the treatment of prostate cancer bone metastasis.Based on this,this article introduces the mechanism of prostate cancer bone metastasis and the research progress of several bone-targeted drugs to provide reference and inspiration for future research.
基金supported by the National Natural Science Foundation of China(21574030,52063007,51863004)Guizhou Province High-Level Innovative Talents Fund([2020]6024)+1 种基金Guizhou Provincial Science and Technology Projects(Grant No.[2022]024)and the Science and Technology Project of Baiyun District,Guiyang City(Grant No.[2020]26)the authors gratefully acknowledge the financial support from the National Engineering Research Center for Compounding and Modification of Polymeric Materials(Guizhou Material Industrial Technology Institute).
文摘Due to the increasing demand for modified polylactide(PLA)meeting“double green”criteria,the research on sustainable plasticizers for PLA has attracted broad attentions.This study reported an open-ring polymerization method to fabricate cellulose(MCC)-g-PCL(poly(ε-caprolactone))copolymers with a fully sustainable and biodegradable component.MCC-g-PCL copolymers were synthesized,characterized,and used as green plasticizers for the PLA toughening.The results indicated that the MCC-g-PCL derivatives play an important role in the compatibility,crystallization,and toughening of the PLA/MCC-g-PCL composites.The mechanical properties of the fully bio-based PLA/MCC-g-PCL composites were optimized by adding 15 wt%MCC-g-PCL,that is,the elongation at break was 22.6%(~376%higher than that of neat PLA),the tensile strength was 47.3 MPa(comparable to that of neat PLA),and the impact strength was 26 J/m(~130%higher than that of neat PLA).DSC results indicated that MCC-g-PCL reduced the Tg of the PLA blend.When the addition amount was 15 wt%,the Tg of the blend was 58.4°C.Compared with MCC,MCC-g-PCL polyester plasticizer has better thermal stability,T5%(°C)can still be maintained above 300°C.The rheological results showed that MCC-g-PCL acted as a plasticizer,the introduction of PCL flexible chain increased the mobility of PLA molecular chain,and decreased the complex viscosity,storage modulus and loss modulus of PLA blends.The MCC-g-PCL derivatives,as a new green plastic additive,have shown an interesting prospect to prepare fully bio-based composites.
基金Supported by Major State Basic Research Development Program of China(973 Program,Grant No.2013CB035400)National Natural Science Foundation of China(Grant Nos.51275451,51575476)Science Fund for Creative Research Groups of National Natural Science Foundation of China(Grant No.51221004)
文摘Achieving highly efficient extrication of the tunnel boring machine(TBM)cutter-head driving system from the collapsed surrounding rock has become a key problem globally,and significant effort has been directed to improve TBM cutter-head extricating ability.In this study,the characteristics of a hydro-viscous device have been investigated to improve extricating performance of the TBM cutter-head.A numerical method based on an explicit pressure-linked equation is presented for computing the film parameters of the HVC,which is then applied to investigate extrication characteristics of a TBM cutter-head with a hydro-viscous clutch(HVC).The explicit pressure-linked equation is derived from the Navier–Stokes equations and the conservation equation,where boundary conditions are involved.The model of a cutter-head driving system with an HVC is established,and the extrication characteristics of the cutterhead driving system are analyzed and compared with three extrication strategies.The variation in extrication torque shows that the linear strategy or positive parabolic strategy are preferred for their relatively high extrication efficiency and low rigid impact,and the effects of throughflow rate on torque transmission are also investigated.The test rig of the TBM cutter-head driving system was set up to validate the numerical method and the model of a cutter-head driving system,and the feasibility of the proposed numerical method for researching the extrication of the TBM cutter-head is verified.
基金supported by National Natural Science Foundation of China(No.22275041No.21774028,No.21574030)+4 种基金Science and Technology Department of Guizhou Province&Guizhou University Joint FundScience and Technology Department of Guizhou Province(Natural Science Key Fund ZK[2021]023Platform&Talents[2016]5652,[2017]5788,[2018]5781,and[2019]5607)Introduced Talent Research Project of Guizhou University([2022]16)LETSGrp2020042402 and Basic research project of Guizhou University([2023]01).
文摘Phenolation is one of the effective strategies to synthesize lignin-based polyphenols,improve lignin’s properties,and extend its value-added applications in biological,medicinal and cosmetic fields.Herein,by taking the structural feature advantage of lignin,an effective and green strategy was developed to molecularly engineer lignin into a robust lignin-3-(2-hydroxyphenyl)propionate ester(LPPE)derivative via a transesterification reaction between 3,4-dihydrocoumarin(DHC)and the aliphatic hydroxyls in lignin under organocatalysis.The strategy is optimized and the novel derivative was systematically characterized by ^(1)H,^(13)C and ^(31)P nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy.The findings indicated that the successful introduction of 3-(2-hydroxyphenyl)propionate groups using a OH groups/DHC/organic base mo-lar ratio of 1꞉1꞉0.3 at 120℃ for 6 h increased the content of phenolic hydroxyl groups from 1.7931 to 3.0179 mmol/g,and the LPPE exhibited excellent ultraviolet-absorbing and antioxidant per-formance with up to 90%free radical scavenging activity within 20 min using 5 mg/mL of LPPE.In addition,good biocompatibility and a high Sun protection factor(SPF)value of 40.9 were achieved at 5%(w)dosage of LPPE in the cream,indicating its significant application potential in sunscreen.
基金National Natural Science Foundation of China(31991194,32025037,and 32125015)Fundamental Research Funds for Central Universities(201941004)State Key Laboratory of Freshwater Ecology and Biotechnology(2019FBZ05).
文摘Meiosis is essential for evolution and genetic diversity in almost all sexual eukaryotic organisms.The mechanisms of meiotic recombination,such as synapsis,have been extensively investigated.However,it is still unclear whether signals from the cytoplasm or even from outside of the cell can regulate the meiosis process.Cilia are microtubule-based structures that protrude from the cell surface and function as signaling hubs to sense extracellular signals.Here,we reported an unexpected and critical role of cilia during meiotic recombination.During gametogenesis of zebrafish,cilia were specifically present in the prophase stages of both primary spermatocytes and primary oocytes.By developing a germ cell-specific CRISPR/Cas9 system,we demonstrated that germ cell-specific depletion of ciliary genes resulted in compromised double-strand break repair,reduced crossover formation,and increased germ cell apoptosis.Our study reveals a previously undiscovered role for cilia during meiosis and suggests that extracellular signals may regulate meiotic recombination via this particular organelle.