BACKGROUND Breast cancer is a multifaceted and formidable disease with profound public health implications.Cell demise mechanisms play a pivotal role in breast cancer pathogenesis,with ATP-triggered cell death attract...BACKGROUND Breast cancer is a multifaceted and formidable disease with profound public health implications.Cell demise mechanisms play a pivotal role in breast cancer pathogenesis,with ATP-triggered cell death attracting mounting interest for its unique specificity and potential therapeutic pertinence.AIM To investigate the impact of ATP-induced cell death(AICD)on breast cancer,enhancing our understanding of its mechanism.METHODS The foundational genes orchestrating AICD mechanisms were extracted from the literature,underpinning the establishment of a prognostic model.Simultaneously,a microRNA(miRNA)prognostic model was constructed that mirrored the gene-based prognostic model.Distinctions between high-and low-risk cohorts within mRNA and miRNA characteristic models were scrutinized,with the aim of delineating common influence mechanisms,substantiated through enrichment analysis and immune infiltration assessment.RESULTS The mRNA prognostic model in this study encompassed four specific mRNAs:P2X purinoceptor 4,pannexin 1,caspase 7,and cyclin 2.The miRNA prognostic model integrated four pivotal miRNAs:hsa-miR-615-3p,hsa-miR-519b-3p,hsa-miR-342-3p,and hsa-miR-324-3p.B cells,CD4+T cells,CD8+T cells,endothelial cells,and macrophages exhibited inverse correlations with risk scores across all breast cancer subtypes.Furthermore,Kyoto Encyclopedia of Genes and Genomes analysis revealed that genes differentially expressed in response to mRNA risk scores significantly enriched 25 signaling pathways,while miRNA risk scores significantly enriched 29 signaling pathways,with 16 pathways being jointly enriched.CONCLUSION Of paramount significance,distinct mRNA and miRNA signature models were devised tailored to AICD,both potentially autonomous prognostic factors.This study's elucidation of the molecular underpinnings of AICD in breast cancer enhances the arsenal of potential therapeutic tools,offering an unparalleled window for innovative interventions.Essentially,this paper reveals the hitherto enigmatic link between AICD and breast cancer,potentially leading to revolutionary progress in personalized oncology.展开更多
Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors.However,measuring the electrical properties of individual nanowires directly remains challengi...Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors.However,measuring the electrical properties of individual nanowires directly remains challenging because of their small size,thereby hindering the comprehensive understanding of nanowire-based device performance.A crucial factor in achieving reliable electrical characterization is establishing well-determined contact conditions between the nanowire sample and the electrodes,which becomes particularly difficult for soft nanowires.Introduced here is a novel technique for measuring the conductivity of an individual nanowire with the aid of automated nanomanipulation using an atomic force microscope.In this method,two nanowire segments cut from the same silver nanowire are positioned onto a pair of gold electrodes,serving as flexible nanoprobes to establish controllable contact with the sample.By changing the contact points along the nanowire sample,conductivity measurements can be performed on different regions,thereby eliminating the influence of contact resistance by analyzing multiple current–voltage curves.Using this approach,the resistivity of a 100-nm-diameter silver nanowire is determined to be 3.49×10^(−8)Ωm.展开更多
An algorithm, Clustering Algorithm Based On Sparse Feature Vector (CABOSFV), was proposed for the high dimensional clustering of binary sparse data. This algorithm compresses the data effectively by using a tool '...An algorithm, Clustering Algorithm Based On Sparse Feature Vector (CABOSFV), was proposed for the high dimensional clustering of binary sparse data. This algorithm compresses the data effectively by using a tool 'Sparse Feature Vector', thus reduces the data scale enormously, and can get the clustering result with only one data scan. Both theoretical analysis and empirical tests showed that CABOSFV is of low computational complexity. The algorithm finds clusters in high dimensional large datasets efficiently and handles noise effectively.展开更多
Transition metal dichalcogenides(TMDCs) belong to a subgroup of two-dimensional(2 D) materials which usually possess thickness-dependent band structures and semiconducting properties. Therefore, for TMDCs to be widely...Transition metal dichalcogenides(TMDCs) belong to a subgroup of two-dimensional(2 D) materials which usually possess thickness-dependent band structures and semiconducting properties. Therefore, for TMDCs to be widely used in electronic and optoelectronic applications, two critical issues need to be addressed, which are thickness-controllable fabrication and doping modulation of TMDCs. In this work, we successfully obtained monolayer WS2 and achieved its efficient doping by chemical vapor deposition and chemical doping, respectively. The n-and p-type dopings of the monolayer WS2 were achieved by drop coating electron donor and acceptor solutions of triphenylphosphine(PPh3) and gold chloride(AuCl_3), respectively, on the surface, which donates and captures electrons to/from the WS2 surface through charge transfer, respectively. Both doping effects were investigated in terms of the electrical properties of the fabricated field effect transistors. After chemical doping, the calculated mobility and density of electrons/holes are around 74.6/39.5 cm^2 · V^(-1) ·s^(-1)and 1.0 x 10^(12)/4.2 x 10^(11) cm^(-2), respectively. Moreover, we fabricated a lateral WS2 p-n homojunction consisting of nondoped n-type and p-doped p-type regions, which showed great potential for photodetection with a response time of 1.5 s and responsivity of 5.8 A/W at V_G = 0 V and V_D = 1 V under 532 nm light illumination.展开更多
Background:A considerable number of muscle development-related genes were differentially expressed in the early stage of avian adipocyte differentiation.However,the functions of them in adipocyte differentiation remai...Background:A considerable number of muscle development-related genes were differentially expressed in the early stage of avian adipocyte differentiation.However,the functions of them in adipocyte differentiation remain largely known.In this study,the myoblast determination protein 1(MYOD1)was selected as a representative of muscle development.We investigated its expression,function,and regulation in avian adipocyte differentiation.Results:The expression of MYOD1 decreased significantly in the early stage of avian adipocyte differentiation.CRIS PR/Cas9-mediated deletion of MYOD1 induced adipocyte differentiation,whereas over-expression of MYOD1 inhibited adipogenesis.The mRNA-seq data showed that MYOD1 could perturb the lipid biosynthetic process during differentiation.Our results showed that MYOD1 directly up-regulates the miR-206 expression by binding the upstream 1200 bp region of miR-206.Then,over-expression of miR-206 can inhibit the adipogenesis.Furthermore,MYOD1 affected the expression of endogenous miR-206 and its target gene Kruppel-like factor 4(KLF4),which is an important activator of adipogenesis.Accordingly,the inhibition of miR-206 or over-expression of KLF4 could counteract the inhibitory effect of MYOD1 on adipocyte differentiation.Conclusions:Our results establish that MYOD1 inhibits adipocyte differentiation by up-regulating miR-206 to suppress the KLF4 expression.These findings identify a novel function of MYOD1 in adipocyte differentiation,suggesting a potential role in body-fat distribution regulation.展开更多
Blind tip reconstruction(BTR) method is one of the favorable methods to estimate the atomic force microscopy(AFM) probe shape. The exact shape of the characterizer is not required for BTR, while the geometry of the sa...Blind tip reconstruction(BTR) method is one of the favorable methods to estimate the atomic force microscopy(AFM) probe shape. The exact shape of the characterizer is not required for BTR, while the geometry of the sample may affect the reconstruction significantly. A cone-shaped array sample was chosen as a characterizer to be evaluated. The target AFM probe to be reconstructed was a diamond triangular pyramid probe with two feature angles, namely front angle(FA) and back angle(BA). Four conical structures with different semi-angles were dilated by the pyramid probe. Simulation of scanning process demonstrates that it is easy to judge from the images of the isolated rotary structure, cone-shaped, the suitability of the sample to be a tip characterizer for a pyramid probe. The cone-shaped array sample was repeatedly scanned 50 times by the diamond probe using an AFM. The series of scanning images shrank gradually and more information of the probe was exhibited in the images, indicating that the characterizer has been more suitable for BTR. The feature angle FA of the characterizer increasingly reduces during the scanning process. A self-adaptive grinding between the probe and the characterizer contributes to BTR of the diamond pyramid probe.展开更多
Atomic force microscope(AFM)-based nanomanipulation has been proved to be a possible method for assembling various nanoparticles into complex patterns and devices.To achieve efficient and fully automated nanomanipulat...Atomic force microscope(AFM)-based nanomanipulation has been proved to be a possible method for assembling various nanoparticles into complex patterns and devices.To achieve efficient and fully automated nanomanipulation,nanoparticles on the substrate must be identified precisely and automatically.This work focuses on an autodetection method for flexible nanowires using a deep learning technique.An instance segmentation network based on You Only Look Once version 3(YOLOv3)and a fully convolutional network(FCN)is applied to segment all movable nanowires in AFM images.Combined with follow-up image morphology and fitting algorithms,this enables detection of postures and positions of nanowires at a high abstraction level.Benefitting from these algorithms,our program is able to automatically detect nanowires of different morphologies with nanometer resolution and has over 90%reliability in the testing dataset.The detection results are less affected by image complexity than the results of existing methods and demonstrate the good robustness of this algorithm.展开更多
Two-dimensional(2 D) transition metal dichalcogenides(TMDCs) such as tungsten diselenide(WSe_(2)) have spead many interesting physical properties, which may become ideal candidates to develop new generation electronic...Two-dimensional(2 D) transition metal dichalcogenides(TMDCs) such as tungsten diselenide(WSe_(2)) have spead many interesting physical properties, which may become ideal candidates to develop new generation electronic and optoelectronic devices. In order to reveal essential features of 2 D TMDCs, it is necessary to fabricate high-quality devices with reliable electrical contact. We systematically analyze the effect of graphene and metal contacts on performance of multilayered WSe_(2) field effect transistors(FETs). The temperature-dependent transport characteristics of both devices are tested.Only graphene-contacted WSe_(2) FETs are observed with the metal-insulator transition phenomenon which mainly attributes to the ultra-clean contact interface and lowered contact barrier. Further characterization on contact barrier demonstrates that graphene contact enables lower contact barrier with WSe_(2) than metal contact, since the Fermi level of graphene can be modulated by the gate bias to match the Fermi level of the channel material. We also analyze the carrier mobility of both devices under different temperatures, revealing that graphene contact can reduce the charge scattering of the device caused by ionized impurities and phonon vibrations in low and room temperature regions, respectively. This work is expected to provide reference for fabricating 2 D material devices with decent performances.展开更多
Animal models of human diseases play a critical role in medical research.Pigs are anatomically and physiologically more like humans than are small rodents such as mice,making pigs an attractive option for modeling hum...Animal models of human diseases play a critical role in medical research.Pigs are anatomically and physiologically more like humans than are small rodents such as mice,making pigs an attractive option for modeling human diseases.Advances in recent years in genetic engineering have facilitated the rapid rise of pig models for use in studies of human disease.In the present review,we summarize the current status of pig models for human cardiovascular,metabolic,neurodegenerative,and various genetic diseases.We also discuss areas that need to be improved.Animal models of human diseases play a critical role in medical research.Advances in recent years in genetic engineering have facilitated the rapid rise of pig models for use in studies of human disease.In the present review,we summarize the current status of pig models for human cardiovascular,metabolic,neurodegenerative,various genetic diseases and xenotransplantation.展开更多
The rapid development of biotechnology has facilitated our understanding of the biological functions of candidate genes for important economic traits in farm animals.Molecular breeding by gene editing has greatly revo...The rapid development of biotechnology has facilitated our understanding of the biological functions of candidate genes for important economic traits in farm animals.Molecular breeding by gene editing has greatly revolutionized the breeding of farm animals.Through gene editing and embryo manipulation,breeds with designed economic or disease-resistant traits can be readily generated.Along with this fast progress,the safety assessment of gene-edited farm animals has attracted public and regulatory attention.This review summarizes the research progress of gene editing in farm animals,focusing on performance improvement,disease resistance,bioreactors,animal welfare,and environmental friendliness.The limitations and future development of gene editing technology in farm animal breeding are also discussed.展开更多
Dear Editor, CRISPR/Cas9 has revolutionized genome editing technology due to its simplicity and robustness (Mali et al., 2013). Several inducible CRISPR/Cas9 systems recently developed make spatiotemporal genome editi...Dear Editor, CRISPR/Cas9 has revolutionized genome editing technology due to its simplicity and robustness (Mali et al., 2013). Several inducible CRISPR/Cas9 systems recently developed make spatiotemporal genome editing possible (Kon ermann et al., 2013;Balboa et al., 2015;Dow et al., 2015;Zetsche et al., 2015;Liu et al., 2016;Kleinjan et al., 2017;Maji et al.. 2017;Senturk et al., 2017;Lu et al., 2018).展开更多
Atomically thin two-dimensional(2D)materials are promising candidates to develop flash memories with premium performances as compared to conventional bulk materials,because of their ultra-thin thickness and highly tun...Atomically thin two-dimensional(2D)materials are promising candidates to develop flash memories with premium performances as compared to conventional bulk materials,because of their ultra-thin thickness and highly tunable electrical properties.So far,most of the reported 2D material based flash memories work in the uni-polar mode,which usually further integrate additional local gate to achieve bi-polar function.However,such approach is volatile,meaning that the gate bias has to be applied persistently to maintain the polarity change and thus increases the power consumption.Here,we report a bi-polar memory based on MoTe_(2)/h-BN/graphene semi-floating gate(SFG)heterostructure,which has non-volatile and dynamically tunable polarity.The SFG configuration has the channel layer of MoTe_(2) and dielectric layer of h-BN half-stacked on the floating gate layer of graphene.The off-graphene half of the MoTe_(2) channel can be tuned between n-type and p-type by simultaneously applying ultraviolet(UV)illumination and electrical field through the back gate,which maintains this polarity after the removal of both stimuli.As a result,the SFG memory can work in the non-volatile bi-polar mode,with a on/off ratio of~100 and switching speed of 1 ms.On the other hand,the on-graphene half of the MoTe_(2) channel remains n-type under UV illumination and electrical bias,so that the MoTe_(2) full floating gate memory maintains n-type,which implements the integration of both n-and p-type memories in a single 2D heterostructure.This capability provides great flexibility for memory devices adapting in various emerging applications.展开更多
The recent development of genome editing technologies has given researchers unprecedented power to alter DNA sequences at chosen genomic loci,thereby generating various genetically edited animal models.This mini-revie...The recent development of genome editing technologies has given researchers unprecedented power to alter DNA sequences at chosen genomic loci,thereby generating various genetically edited animal models.This mini-review briefly summarizes the development of major genome editing tools,focusing on the application of these tools to generate animal models in multiple species.展开更多
Development of a green and sustainable agriculture is one of the greatest challenges for the globe to feed the increasingly growing human population.Among the multiplicity of factors that contribute to highly efficien...Development of a green and sustainable agriculture is one of the greatest challenges for the globe to feed the increasingly growing human population.Among the multiplicity of factors that contribute to highly efficient agriculture,animal and crop breeding have always been regarded as a top priority in the agricultural practice of all agriculturally developed nations.Modern animal and crop breeding,following the theories of Mendel and Darwin.展开更多
基金Supported by National Natural Science Foundation of China,No.81960877University Innovation Fund of Gansu Province,No.2021A-076+5 种基金Gansu Province Science and Technology Plan(Innovation Base and Talent Plan),No.21JR7RA561Natural Science Foundation of Gansu Province,No.21JR1RA267 and No.22JR5RA582Education Technology Innovation Project of Gansu Province,No.2022A-067Innovation Fund of Higher Education of Gansu Province,No.2023A-088Gansu Province Science and Technology Plan International Cooperation Field Project,No.23YFWA0005and Open Project of Key Laboratory of Dunhuang Medicine and Transformation of Ministry of Education,No.DHYX21-07,No.DHYX22-05,and No.DHYX21-01.
文摘BACKGROUND Breast cancer is a multifaceted and formidable disease with profound public health implications.Cell demise mechanisms play a pivotal role in breast cancer pathogenesis,with ATP-triggered cell death attracting mounting interest for its unique specificity and potential therapeutic pertinence.AIM To investigate the impact of ATP-induced cell death(AICD)on breast cancer,enhancing our understanding of its mechanism.METHODS The foundational genes orchestrating AICD mechanisms were extracted from the literature,underpinning the establishment of a prognostic model.Simultaneously,a microRNA(miRNA)prognostic model was constructed that mirrored the gene-based prognostic model.Distinctions between high-and low-risk cohorts within mRNA and miRNA characteristic models were scrutinized,with the aim of delineating common influence mechanisms,substantiated through enrichment analysis and immune infiltration assessment.RESULTS The mRNA prognostic model in this study encompassed four specific mRNAs:P2X purinoceptor 4,pannexin 1,caspase 7,and cyclin 2.The miRNA prognostic model integrated four pivotal miRNAs:hsa-miR-615-3p,hsa-miR-519b-3p,hsa-miR-342-3p,and hsa-miR-324-3p.B cells,CD4+T cells,CD8+T cells,endothelial cells,and macrophages exhibited inverse correlations with risk scores across all breast cancer subtypes.Furthermore,Kyoto Encyclopedia of Genes and Genomes analysis revealed that genes differentially expressed in response to mRNA risk scores significantly enriched 25 signaling pathways,while miRNA risk scores significantly enriched 29 signaling pathways,with 16 pathways being jointly enriched.CONCLUSION Of paramount significance,distinct mRNA and miRNA signature models were devised tailored to AICD,both potentially autonomous prognostic factors.This study's elucidation of the molecular underpinnings of AICD in breast cancer enhances the arsenal of potential therapeutic tools,offering an unparalleled window for innovative interventions.Essentially,this paper reveals the hitherto enigmatic link between AICD and breast cancer,potentially leading to revolutionary progress in personalized oncology.
基金supported by the National Natural Science Foundation of China(Grant No.61973233).
文摘Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors.However,measuring the electrical properties of individual nanowires directly remains challenging because of their small size,thereby hindering the comprehensive understanding of nanowire-based device performance.A crucial factor in achieving reliable electrical characterization is establishing well-determined contact conditions between the nanowire sample and the electrodes,which becomes particularly difficult for soft nanowires.Introduced here is a novel technique for measuring the conductivity of an individual nanowire with the aid of automated nanomanipulation using an atomic force microscope.In this method,two nanowire segments cut from the same silver nanowire are positioned onto a pair of gold electrodes,serving as flexible nanoprobes to establish controllable contact with the sample.By changing the contact points along the nanowire sample,conductivity measurements can be performed on different regions,thereby eliminating the influence of contact resistance by analyzing multiple current–voltage curves.Using this approach,the resistivity of a 100-nm-diameter silver nanowire is determined to be 3.49×10^(−8)Ωm.
文摘An algorithm, Clustering Algorithm Based On Sparse Feature Vector (CABOSFV), was proposed for the high dimensional clustering of binary sparse data. This algorithm compresses the data effectively by using a tool 'Sparse Feature Vector', thus reduces the data scale enormously, and can get the clustering result with only one data scan. Both theoretical analysis and empirical tests showed that CABOSFV is of low computational complexity. The algorithm finds clusters in high dimensional large datasets efficiently and handles noise effectively.
基金Project supported by the National Natural Science Foundation of China(Grant No.21405109)Seed Foundation of State Key Laboratory of Precision Measurement Technology and Instruments,China(Grant No.1710)
文摘Transition metal dichalcogenides(TMDCs) belong to a subgroup of two-dimensional(2 D) materials which usually possess thickness-dependent band structures and semiconducting properties. Therefore, for TMDCs to be widely used in electronic and optoelectronic applications, two critical issues need to be addressed, which are thickness-controllable fabrication and doping modulation of TMDCs. In this work, we successfully obtained monolayer WS2 and achieved its efficient doping by chemical vapor deposition and chemical doping, respectively. The n-and p-type dopings of the monolayer WS2 were achieved by drop coating electron donor and acceptor solutions of triphenylphosphine(PPh3) and gold chloride(AuCl_3), respectively, on the surface, which donates and captures electrons to/from the WS2 surface through charge transfer, respectively. Both doping effects were investigated in terms of the electrical properties of the fabricated field effect transistors. After chemical doping, the calculated mobility and density of electrons/holes are around 74.6/39.5 cm^2 · V^(-1) ·s^(-1)and 1.0 x 10^(12)/4.2 x 10^(11) cm^(-2), respectively. Moreover, we fabricated a lateral WS2 p-n homojunction consisting of nondoped n-type and p-doped p-type regions, which showed great potential for photodetection with a response time of 1.5 s and responsivity of 5.8 A/W at V_G = 0 V and V_D = 1 V under 532 nm light illumination.
基金supported by the National Waterfowl-Industry Technology Research System(CARS-42)National Nature Science Foundation of China(31972525,31572388)+1 种基金Beijing Municipal Science&Technology Commission(Z181100002418008)Key-Area Research and Development Program of Guangdong Province(2020B020222003).
文摘Background:A considerable number of muscle development-related genes were differentially expressed in the early stage of avian adipocyte differentiation.However,the functions of them in adipocyte differentiation remain largely known.In this study,the myoblast determination protein 1(MYOD1)was selected as a representative of muscle development.We investigated its expression,function,and regulation in avian adipocyte differentiation.Results:The expression of MYOD1 decreased significantly in the early stage of avian adipocyte differentiation.CRIS PR/Cas9-mediated deletion of MYOD1 induced adipocyte differentiation,whereas over-expression of MYOD1 inhibited adipogenesis.The mRNA-seq data showed that MYOD1 could perturb the lipid biosynthetic process during differentiation.Our results showed that MYOD1 directly up-regulates the miR-206 expression by binding the upstream 1200 bp region of miR-206.Then,over-expression of miR-206 can inhibit the adipogenesis.Furthermore,MYOD1 affected the expression of endogenous miR-206 and its target gene Kruppel-like factor 4(KLF4),which is an important activator of adipogenesis.Accordingly,the inhibition of miR-206 or over-expression of KLF4 could counteract the inhibitory effect of MYOD1 on adipocyte differentiation.Conclusions:Our results establish that MYOD1 inhibits adipocyte differentiation by up-regulating miR-206 to suppress the KLF4 expression.These findings identify a novel function of MYOD1 in adipocyte differentiation,suggesting a potential role in body-fat distribution regulation.
基金supported by the National Natural Science Foundation of China(Grant No.51305298,No.51675379)Tianjin Research Program of Application Foundation and Advanced Technology(Grant No.13JCQNJC04700)
文摘Blind tip reconstruction(BTR) method is one of the favorable methods to estimate the atomic force microscopy(AFM) probe shape. The exact shape of the characterizer is not required for BTR, while the geometry of the sample may affect the reconstruction significantly. A cone-shaped array sample was chosen as a characterizer to be evaluated. The target AFM probe to be reconstructed was a diamond triangular pyramid probe with two feature angles, namely front angle(FA) and back angle(BA). Four conical structures with different semi-angles were dilated by the pyramid probe. Simulation of scanning process demonstrates that it is easy to judge from the images of the isolated rotary structure, cone-shaped, the suitability of the sample to be a tip characterizer for a pyramid probe. The cone-shaped array sample was repeatedly scanned 50 times by the diamond probe using an AFM. The series of scanning images shrank gradually and more information of the probe was exhibited in the images, indicating that the characterizer has been more suitable for BTR. The feature angle FA of the characterizer increasingly reduces during the scanning process. A self-adaptive grinding between the probe and the characterizer contributes to BTR of the diamond pyramid probe.
基金supported by the National Nature Science Foundation of China(Grant No.61973233).
文摘Atomic force microscope(AFM)-based nanomanipulation has been proved to be a possible method for assembling various nanoparticles into complex patterns and devices.To achieve efficient and fully automated nanomanipulation,nanoparticles on the substrate must be identified precisely and automatically.This work focuses on an autodetection method for flexible nanowires using a deep learning technique.An instance segmentation network based on You Only Look Once version 3(YOLOv3)and a fully convolutional network(FCN)is applied to segment all movable nanowires in AFM images.Combined with follow-up image morphology and fitting algorithms,this enables detection of postures and positions of nanowires at a high abstraction level.Benefitting from these algorithms,our program is able to automatically detect nanowires of different morphologies with nanometer resolution and has over 90%reliability in the testing dataset.The detection results are less affected by image complexity than the results of existing methods and demonstrate the good robustness of this algorithm.
基金supported by the National Natural Science Foundation of China (Grant No. 52075385)the National Key R&D Program of China (2018YFA0307200)the 111 Project (Grant No. B07014)。
文摘Two-dimensional(2 D) transition metal dichalcogenides(TMDCs) such as tungsten diselenide(WSe_(2)) have spead many interesting physical properties, which may become ideal candidates to develop new generation electronic and optoelectronic devices. In order to reveal essential features of 2 D TMDCs, it is necessary to fabricate high-quality devices with reliable electrical contact. We systematically analyze the effect of graphene and metal contacts on performance of multilayered WSe_(2) field effect transistors(FETs). The temperature-dependent transport characteristics of both devices are tested.Only graphene-contacted WSe_(2) FETs are observed with the metal-insulator transition phenomenon which mainly attributes to the ultra-clean contact interface and lowered contact barrier. Further characterization on contact barrier demonstrates that graphene contact enables lower contact barrier with WSe_(2) than metal contact, since the Fermi level of graphene can be modulated by the gate bias to match the Fermi level of the channel material. We also analyze the carrier mobility of both devices under different temperatures, revealing that graphene contact can reduce the charge scattering of the device caused by ionized impurities and phonon vibrations in low and room temperature regions, respectively. This work is expected to provide reference for fabricating 2 D material devices with decent performances.
基金The National Key Research and Development Program of China(Grant No.2021YFA0805900)the 2020 Research Program of Sanya Yazhou Bay Science and Technology City(Grant No.202002011)+1 种基金the National Natural Science Foundation of China(Grant No.32002180)the Key Research and Development Program of Hainan Province,China(Grant No.ZDYF2021SHFZ230)。
文摘Animal models of human diseases play a critical role in medical research.Pigs are anatomically and physiologically more like humans than are small rodents such as mice,making pigs an attractive option for modeling human diseases.Advances in recent years in genetic engineering have facilitated the rapid rise of pig models for use in studies of human disease.In the present review,we summarize the current status of pig models for human cardiovascular,metabolic,neurodegenerative,and various genetic diseases.We also discuss areas that need to be improved.Animal models of human diseases play a critical role in medical research.Advances in recent years in genetic engineering have facilitated the rapid rise of pig models for use in studies of human disease.In the present review,we summarize the current status of pig models for human cardiovascular,metabolic,neurodegenerative,various genetic diseases and xenotransplantation.
基金supported by the National Key Research and Development Program of China(2021YFA0805900)the 2020 Research Program of Sanya Yazhou Bay Science and Technology City(202002011)+1 种基金the National Natural Science Foundation of China(32002180)the Key Research and Development Program of Hainan Province,China(ZDYF2021SHFZ230)
文摘The rapid development of biotechnology has facilitated our understanding of the biological functions of candidate genes for important economic traits in farm animals.Molecular breeding by gene editing has greatly revolutionized the breeding of farm animals.Through gene editing and embryo manipulation,breeds with designed economic or disease-resistant traits can be readily generated.Along with this fast progress,the safety assessment of gene-edited farm animals has attracted public and regulatory attention.This review summarizes the research progress of gene editing in farm animals,focusing on performance improvement,disease resistance,bioreactors,animal welfare,and environmental friendliness.The limitations and future development of gene editing technology in farm animal breeding are also discussed.
文摘Dear Editor, CRISPR/Cas9 has revolutionized genome editing technology due to its simplicity and robustness (Mali et al., 2013). Several inducible CRISPR/Cas9 systems recently developed make spatiotemporal genome editing possible (Kon ermann et al., 2013;Balboa et al., 2015;Dow et al., 2015;Zetsche et al., 2015;Liu et al., 2016;Kleinjan et al., 2017;Maji et al.. 2017;Senturk et al., 2017;Lu et al., 2018).
基金supported by the National Key R&D Program(No.2018YFA0307200)the National Science Foundation of China(NSFC,No.52075385 and 12034001)the 111 Project(No.B07014).
文摘Atomically thin two-dimensional(2D)materials are promising candidates to develop flash memories with premium performances as compared to conventional bulk materials,because of their ultra-thin thickness and highly tunable electrical properties.So far,most of the reported 2D material based flash memories work in the uni-polar mode,which usually further integrate additional local gate to achieve bi-polar function.However,such approach is volatile,meaning that the gate bias has to be applied persistently to maintain the polarity change and thus increases the power consumption.Here,we report a bi-polar memory based on MoTe_(2)/h-BN/graphene semi-floating gate(SFG)heterostructure,which has non-volatile and dynamically tunable polarity.The SFG configuration has the channel layer of MoTe_(2) and dielectric layer of h-BN half-stacked on the floating gate layer of graphene.The off-graphene half of the MoTe_(2) channel can be tuned between n-type and p-type by simultaneously applying ultraviolet(UV)illumination and electrical field through the back gate,which maintains this polarity after the removal of both stimuli.As a result,the SFG memory can work in the non-volatile bi-polar mode,with a on/off ratio of~100 and switching speed of 1 ms.On the other hand,the on-graphene half of the MoTe_(2) channel remains n-type under UV illumination and electrical bias,so that the MoTe_(2) full floating gate memory maintains n-type,which implements the integration of both n-and p-type memories in a single 2D heterostructure.This capability provides great flexibility for memory devices adapting in various emerging applications.
文摘The recent development of genome editing technologies has given researchers unprecedented power to alter DNA sequences at chosen genomic loci,thereby generating various genetically edited animal models.This mini-review briefly summarizes the development of major genome editing tools,focusing on the application of these tools to generate animal models in multiple species.
文摘Development of a green and sustainable agriculture is one of the greatest challenges for the globe to feed the increasingly growing human population.Among the multiplicity of factors that contribute to highly efficient agriculture,animal and crop breeding have always been regarded as a top priority in the agricultural practice of all agriculturally developed nations.Modern animal and crop breeding,following the theories of Mendel and Darwin.
