Integrated satellite unmanned aerial vehicle relay networks(ISUAVRNs)have become a prominent topic in recent years.This paper investigates the average secrecy capacity(ASC)for reconfigurable intelligent surface(RIS)-e...Integrated satellite unmanned aerial vehicle relay networks(ISUAVRNs)have become a prominent topic in recent years.This paper investigates the average secrecy capacity(ASC)for reconfigurable intelligent surface(RIS)-enabled ISUAVRNs.Especially,an eve is considered to intercept the legitimate information from the considered secrecy system.Besides,we get detailed expressions for the ASC of the regarded secrecy system with the aid of the reconfigurable intelligent.Furthermore,to gain insightful results of the major parameters on the ASC in high signalto-noise ratio regime,the approximate investigations are further gotten,which give an efficient method to value the secrecy analysis.At last,some representative computer results are obtained to prove the theoretical findings.展开更多
We investigated the anti-tumor effects of dual cancer specific-oncolytic adenovirus Ad-VP on esophageal cancer(EC).The anti-tumor activity of Ad-VP was compared with that of the control recombinant adenoviruses(Ad-GP,...We investigated the anti-tumor effects of dual cancer specific-oncolytic adenovirus Ad-VP on esophageal cancer(EC).The anti-tumor activity of Ad-VP was compared with that of the control recombinant adenoviruses(Ad-GP,Ad-Apoptin,Ad-EGFP) in human esophageal cancer cell EC-109 and human normal liver cell L02 in vitro.In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assays,the growth of EC-109 cells was slightly inhibited by Ad-GP,Ad-Apoptin and Ad-EGFP.However,Ad-VP induced a significant cytotoxic effect.Infection of EC-109 cells with Ad-VP resulted in a significant induction of apoptosis of them in vitro,detected by 4',6-diamidino-2-phenylindole(DAPI) or acridine orange and ethidium bromide staining.The results of Western blot and flow cytometric assay indicate the loss of mitochondrial membrane potential(ΔΨ m),the release of cytochrome c and the activation of caspase-3,6 and 7 in Ad-VP infected EC-109 cells.In contrast,all these assays show almost no effects of the recombinant adenoviruses on L02 cells.These results demonstrate that the treatment of tumors with Ad-VP selectively inhibits tumor growth and induces apoptosis of esophageal cancer cells.Ad-VP may provide a novel and powerful strategy for cancer gene therapy.展开更多
Previous studies have shown that the ATP-P2 X4 receptor signaling pathway mediates the activation of the Nod-like receptor family protein 3(NLRP3)inflammasome.The NLRP3 inflammasome may promote renal interstitial infl...Previous studies have shown that the ATP-P2 X4 receptor signaling pathway mediates the activation of the Nod-like receptor family protein 3(NLRP3)inflammasome.The NLRP3 inflammasome may promote renal interstitial inflammation in diabetic nephropathy.As inflammation also plays an important role in the pathogenesis of Parkinson's disease,we hypothesized that the ATP-P2 X4 receptor signaling pathway may activate the NLRP3 inflammasome in Parkinson's disease.A male rat model of Parkinson's disease was induced by stereotactic injection of 6-hydroxydopamine into the pars compacta of the substantia nigra.The P2 X4 receptor and the NLRP3 inflammasome(interleukin-1βand interleukin-18)were activated.Intracerebroventricular injection of the selective P2 X4 receptor antagonist 5-(3-bromophenyl)-1,3-dihydro-2 H-benzofuro[3,2-e]-1,4-diazepin-2-one(5-BDBD)or knockdown of P2 X4 receptor expression by si RNA inhibited the activation of the NLRP3 inflammasome and alleviated dopaminergic neurodegeneration and neuroinflammation.Our results suggest that the ATP-P2 X4 receptor signaling pathway mediates NLRP3 inflammasome activation,dopaminergic neurodegeneration,and dopamine levels.These findings reveal a novel role of the ATP-P2 X4 axis in the molecular mechanisms underlying Parkinson's disease,thus providing a new target for treatment.This study was approved by the Animal Ethics Committee of Qingdao University,China,on March 5,2015(approval No.QYFYWZLL 26119).展开更多
To investigate the stimulated activity of T cells and the anti-tumor properties of hemagglutinin-neuraminidase(HN) of Newcastle disease virus(NDV) strain Changchun(NDVcc), the expression of HN gene in hepatoma cells(h...To investigate the stimulated activity of T cells and the anti-tumor properties of hemagglutinin-neuraminidase(HN) of Newcastle disease virus(NDV) strain Changchun(NDVcc), the expression of HN gene in hepatoma cells(human HepG-2 and mouse H22 cells) infected with the recombinant adenovirus(Ad-HN) was identified by Western blot analysis and flow cytometry. Sialidase activity of NDVcc HN expressed by Ad-HN was assayed by the periodate-resorcinol method. The in vivo anti-tumor effects of NDVcc HN were evaluated in the H22 solid tumor model. Regional lymph nodes of the mouse model treated with Ad-HN were removed to harvest T lymphocytes and evaluating the specific cytotoxicity of cytotoxic T lymphocyte(CTL) and natural killer(NK) cells by an L-lactate dehydrogenase(LDH) assay, in the mean time, the secretion of cytokines was analyzed by enzyme linked immunosorbent assays(ELISA). The results show that NDVcc HN was effectively expressed by Ad-HN in HepG-2 and H22 cells. The sialidase activity assay showed that Ad-HN significantly reduced sialic acid level of the hepatoma cells compared with the cells infected the empty adenovirus vector(Ad-mock). When treated with Ad-HN, the growth of subcutaneous H22 primary tumors in C57BL/6 mice was suppressed, and the mean mice survival increased. In addition, the treatment of Ad-HN elicited strong NK and CTL responses, and high levels of Th1 cytokines, such as IL-2 and IFN-γ. In conclusion, NDVcc HN effectively elicits T cell-mediate anti-tumor cytotoxicity via sialidase activity and may be a novel strategy for cancer immunotherapy.展开更多
BACKGROUND: With developments of tissue engineering and genetic engineering, we aim to culture myoblasts, which are characterized by high purity, high quality and high production, for wide application in neural regene...BACKGROUND: With developments of tissue engineering and genetic engineering, we aim to culture myoblasts, which are characterized by high purity, high quality and high production, for wide application in neural regeneration researches. OBJECTIVE: To modify traditional dissociation method in order to obtain myoblasts, which are characterized by high purity, high quality and high production, and explore the biological properties under in vitro culture. DESIGN: Observational study. SETTING: Basic Institute of Academy of Military Medical Sciences of Chinese PLA. MATERIALS: Four neonatal Wistar rats of 5 days old, both genders and mean body mass of 10 g were selected in this study. The main reagents and devices were detailed as follows: DMEM medium (Gibco Company), fetus bovine serum (FBS, Hycolne Company), collagenase Ⅱ(Sigma Company), trypsin (Sigma Company), dispase Ⅱ (Sigma Company), desmin antibody (Fuzhou Maixin Company), antibody Ⅱ and ABC kit (Wuhan Boster Biotechnology Company), desk centrifuge (KUBATO, Japan), and inverted phase contrast microscope (LEICA DMIRB, Germany). METHODS: The experiment was carried out in the Basic Institute of Academy of Military Medical Sciences of Chinese PLA from June to October 2006. Neonatal rats were sacrificed under sterile condition to obtain skeletal muscles of limbs, which were washed with cold PBS (containing benzylpenicillin and estreptomicina), and muscular tissue was sheared into pieces. Then, those muscular pieces were added with mixed digestive enzyme (containing 2 g/L collagenase Ⅱ + 5 g/L dispase Ⅱ + 0.28 g/L CaCl2) as twice volume as pieces, dealt with mechanical pipetting for 5 minutes and cultured in CO2 incubator for 10 minutes. The operation was done for three times and the muscular pieces were digested for 45 minutes in total. Moreover, cells were suspended again in order to obtain myoblasts from skeletal muscle of neonatal rats. In addition, myoblasts were purified with differential attachment technique and enzyme digestion so as to observe morphological characteristics and growth, draw growth curve, analyze surface structure under scanning electron microscope, and evaluate with Desmin immunohistochemical staining. MAIN OUTCOME MEASURES: Morphological characteristics and growth of myoblasts cultured in vitro. RESULTS: ① Growth of myoblasts of skeletal muscle: Primary cells had well growth, mature and differentiation. The positive rate of Desmin was 94% and purification of cells was ideal. Growth curve of cells demonstrated that myoblasts which were characterized by high purification started proliferation plentiful through transient growth lag phase (about at one or two days after inoculation). If myoblasts were not dealt with any interventions, they might become sarcotubule gradually at 3–5 days after proliferative phase. During this period, myoblasts maintained a monocaryon-bipolarity state under inverted phase contrast microscope. Furthermore, the growth of cells was the strongest and reproductive activity was the most powerful. This suggested that myotube started to form; in addition, muscle fiber of contractility might form under a well culturing condition. ② Immunocytochemical stain with desmin antibody: Interzonal fiber of desmin from myoblasts showed strongly positive reaction. Positive staining existed in cytoplasm had a high nucleus-cytoplasm ratio. However, myoblasts showed negative or mildly positive reaction. CONCLUSION: It is ideal for modified multi-enzymatic digestion and double purification method to dissociate and purify myoblasts of skeletal muscle; meanwhile, these two methods are both the effective ways to provide convenient conditions to obtain seed cells for neural regeneration researches.展开更多
Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using a...Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.展开更多
In this paper,physical layer security techniques are investigated for cooperative multi-input multi-output(C-MIMO),which operates as an underlaid cognitive radio system that coexists with a primary user(PU).The underl...In this paper,physical layer security techniques are investigated for cooperative multi-input multi-output(C-MIMO),which operates as an underlaid cognitive radio system that coexists with a primary user(PU).The underlaid secrecy paradigm is enabled by improving the secrecy rate towards the C-MIMO receiver and reducing the interference towards the PU.Such a communication model is especially suitable for implementing Industrial Internet of Things(IIoT)systems in the unlicensed spectrum,which can trade off spectral efficiency and information secrecy.To this end,we propose an eigenspace-adaptive precoding(EAP)method and formulate the secrecy rate optimization problem,which is subject to both the single device power constraint and the interference power constraint.This precoder design is enabled by decomposing the original optimization problem into eigenspace selection and power allocation sub-problems.Herein,the eigenvectors are adaptively selected by the transmitter according to the channel conditions of the underlaid users and the PUs.In addition,a simplified EAP method is proposed for large-dimensional C-MIMO transmission,exploiting the additional spatial degree of freedom for a low-complexity secrecy precoder design.Numerical results show that by transmitting signal and artificial noise in the properly selected eigenspace,C-MIMO can eliminate the secrecy outage and outperforms the fixed eigenspace precoding methods.Moreover,the proposed simplified EAP method for the large-dimensional C-MIMO can significantly improve the secrecy rate.展开更多
In this paper,we investigate the feasibility and performance of the covert communication with a spectrum sharing relay in the finite blocklength regime.Specifically,the relay opportunistically forwards the source'...In this paper,we investigate the feasibility and performance of the covert communication with a spectrum sharing relay in the finite blocklength regime.Specifically,the relay opportunistically forwards the source's messages to the primary receiver or conveys the covert messages to its own receiver via the sharing spectrum,while the warden attempts to detect the transmission.First,we derive a lower bound on the covertness constraint,and the analytical expressions of both the primary average effective covert throughput(AECT)and sum AECT are presented by considering the overall decoding error performance.Then,we formulate two optimization problems to maximize the primary and sum AECT respectively by optimizing the blocklength and the transmit power at the source and the relay.Our examinations show that there exists an optimal blocklength to maximize the primary and sum AECT.Besides,it is revealed that,to maximize the primary AECT,the optimal transmit power of each hop increases as its channel quality deteriorates.Furthermore,in the optimization for maximizing the sum AECT,the optimal transmit power at the source equals to zero when the channel quality from relay to the secondary receiver is not weaker than that from relay to the primary receiver.展开更多
In this paper,we investigate covert communications in data collected IoT with NOMA,where the paired sensor nodes S_(m) and S_(n) transmit covert messages to a legitimate receiver(Bob)in the presence of a Warden(Willie...In this paper,we investigate covert communications in data collected IoT with NOMA,where the paired sensor nodes S_(m) and S_(n) transmit covert messages to a legitimate receiver(Bob)in the presence of a Warden(Willie).To confuse the detection at Willie,an extra multi-antenna friendly jammer(Jammer)has been employed to transmit artificial noise(AN)with random power.Based on the CSI of Willie is available or not at Jammer,three AN transmission schemes,including null-space artificial noise(NAN),transmit antenna selection(TAS),and zeroforcing beamforming(ZFB),are proposed.Furthermore,the closed-form expressions of expected minimum detection error probability(EMDEP)and joint connection outage probability(JCOP)are derived to measure covertness and reliability,respectively.Finally,the maximum effective covert rate(ECR)is obtained with a given covertness constraint.The numerical results show that ZFB scheme has the best maximum ECR in the case of the number of antennas satisfies N>2,and the same maximum ECR can be achieved in ZFB and NAN schemes with N=2.Moreover,TAS scheme also can improve the maximum ECR compared with the benchmark scheme(i.e.,signal-antenna jammer).In addition,a proper NOMA node pairing can further improve the maximum ECR.展开更多
Prophylactic DNA vaccines against the influenza virus are promising alternatives to conventional vaccines.In this study,we generated two candidate gene-based influenza vaccines encoding either the seasonal or pandemic...Prophylactic DNA vaccines against the influenza virus are promising alternatives to conventional vaccines.In this study,we generated two candidate gene-based influenza vaccines encoding either the seasonal or pandemic hemagglutinin antigen(HA) from the strains A/New Caledonia/20/99(H1N1)(pV1A5) and A/California/04/2009(H1N1)(pVEH1) ,respectively.After verifying antigen expression,the immunogenicity of the vaccines delivered intramuscularly with electroporation was tested in a mouse model.Sera of immunized animals were tested in hemagglutination inhibition assays and by ELISA for the presence of HA-specific antibodies.HA-specific T-cells were also measured in IFN-γELISpot assays.The protective efficacy of the candidate influenza vaccines was evaluated by measuring mortality rates and body weight after a challenge with 100 LD50 of mouse-adapted A/New Caledonia/20/99(H1N1) .Mice immunized with either one of the two vaccines showed significantly higher T cell and humoral immune responses(P<0.05) than the pVAX1 control group.Additionally,the pV1A5 vaccine effectively protected the mice against a lethal homologous mouse-adapted virus challenge with a survival rate of 100%compared with a 40%survival rate in the pVEH1 vaccinated group(P<0.05) .Our study indicates that the seasonal influenza DNA vaccine completely protects against the homologous A/New Caledonia/20/99 virus(H1N1) ,while the pandemic influenza DNA vaccine only partially protects against this virus.展开更多
Hemagglutinin-neuramidinase(HN) is one of the most important surface structure proteins of the Newcastle disease virus(NDV). HN not only mediates receptor recognition but also possesses neuraminidase(NA) activity, whi...Hemagglutinin-neuramidinase(HN) is one of the most important surface structure proteins of the Newcastle disease virus(NDV). HN not only mediates receptor recognition but also possesses neuraminidase(NA) activity, which gives it the ability to cleave a component of those receptors, NAcneu. Previous studies have demonstrated that HN has interesting anti-neoplastic and immune-stimulating properties in mammalian species, including humans. To explore the application of the HN gene in cancer gene therapy, we constructed a Lewis lung carcinoma(LLC) solid tumor model using C57BL/6 mice. Mice were injected intratumorally with the recombinant adenovirus expressing HN gene(Ad-HN), and the effect of HN was explored by natural killer cell activity assay, cytotoxic lymphocyte activity assay, T cell subtype evaluation, and Th1/Th2 cytokines analysis. The results demonstrate that HN not only can elicit clonal expansion of both CD4+ and CD8+ T cell populations and cytotoxic T lymphocyte(CTL) and killer cell response, but also skews the immune response toward Th1. Thus, vaccination with Ad-HN may be a potential strategy for cancer gene therapy.展开更多
To the Editor:The current coronavirus disease-19(COVID-19)pandemic spurs the development of antiviral drugs for SARS-CoV-2,as the number of patients with viral infections continues to rise globally in the context of w...To the Editor:The current coronavirus disease-19(COVID-19)pandemic spurs the development of antiviral drugs for SARS-CoV-2,as the number of patients with viral infections continues to rise globally in the context of widespread vaccination.Targeting the interaction between the receptor binding domain(RBD)of SARS-CoV-2 spike protein and the host cell ACE2 is a promising therapeutic strategy to effectively inhibit viral entry.展开更多
基金the National Natural Science Foundation of China under Grants 62001517 and 61971474the Beijing Nova Program under Grant Z201100006820121.
文摘Integrated satellite unmanned aerial vehicle relay networks(ISUAVRNs)have become a prominent topic in recent years.This paper investigates the average secrecy capacity(ASC)for reconfigurable intelligent surface(RIS)-enabled ISUAVRNs.Especially,an eve is considered to intercept the legitimate information from the considered secrecy system.Besides,we get detailed expressions for the ASC of the regarded secrecy system with the aid of the reconfigurable intelligent.Furthermore,to gain insightful results of the major parameters on the ASC in high signalto-noise ratio regime,the approximate investigations are further gotten,which give an efficient method to value the secrecy analysis.At last,some representative computer results are obtained to prove the theoretical findings.
基金Supported by the Genetically Modified Organisms Breeding Major Project of China(No.2009ZX08006-002B)the National Natural Science Foundation of China(Nos.81101140,81072210)+1 种基金the Key Technologies Research and Development Program of Jilin Province,China(Nos.10ZDGG007,201015166)the China Postdoctoral Science Foundation Funded Project(No.20100481057)
文摘We investigated the anti-tumor effects of dual cancer specific-oncolytic adenovirus Ad-VP on esophageal cancer(EC).The anti-tumor activity of Ad-VP was compared with that of the control recombinant adenoviruses(Ad-GP,Ad-Apoptin,Ad-EGFP) in human esophageal cancer cell EC-109 and human normal liver cell L02 in vitro.In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assays,the growth of EC-109 cells was slightly inhibited by Ad-GP,Ad-Apoptin and Ad-EGFP.However,Ad-VP induced a significant cytotoxic effect.Infection of EC-109 cells with Ad-VP resulted in a significant induction of apoptosis of them in vitro,detected by 4',6-diamidino-2-phenylindole(DAPI) or acridine orange and ethidium bromide staining.The results of Western blot and flow cytometric assay indicate the loss of mitochondrial membrane potential(ΔΨ m),the release of cytochrome c and the activation of caspase-3,6 and 7 in Ad-VP infected EC-109 cells.In contrast,all these assays show almost no effects of the recombinant adenoviruses on L02 cells.These results demonstrate that the treatment of tumors with Ad-VP selectively inhibits tumor growth and induces apoptosis of esophageal cancer cells.Ad-VP may provide a novel and powerful strategy for cancer gene therapy.
基金supported by the National Natural Science Foundation of China,No.81971192(to AMX)。
文摘Previous studies have shown that the ATP-P2 X4 receptor signaling pathway mediates the activation of the Nod-like receptor family protein 3(NLRP3)inflammasome.The NLRP3 inflammasome may promote renal interstitial inflammation in diabetic nephropathy.As inflammation also plays an important role in the pathogenesis of Parkinson's disease,we hypothesized that the ATP-P2 X4 receptor signaling pathway may activate the NLRP3 inflammasome in Parkinson's disease.A male rat model of Parkinson's disease was induced by stereotactic injection of 6-hydroxydopamine into the pars compacta of the substantia nigra.The P2 X4 receptor and the NLRP3 inflammasome(interleukin-1βand interleukin-18)were activated.Intracerebroventricular injection of the selective P2 X4 receptor antagonist 5-(3-bromophenyl)-1,3-dihydro-2 H-benzofuro[3,2-e]-1,4-diazepin-2-one(5-BDBD)or knockdown of P2 X4 receptor expression by si RNA inhibited the activation of the NLRP3 inflammasome and alleviated dopaminergic neurodegeneration and neuroinflammation.Our results suggest that the ATP-P2 X4 receptor signaling pathway mediates NLRP3 inflammasome activation,dopaminergic neurodegeneration,and dopamine levels.These findings reveal a novel role of the ATP-P2 X4 axis in the molecular mechanisms underlying Parkinson's disease,thus providing a new target for treatment.This study was approved by the Animal Ethics Committee of Qingdao University,China,on March 5,2015(approval No.QYFYWZLL 26119).
基金Supported by the Genetically Modified Organisms Breeding Major Project of China(No.2009ZX08006-002B)the Key Technologies Research and Development Programme of Jilin Province, China(No.10ZDGG007)
文摘To investigate the stimulated activity of T cells and the anti-tumor properties of hemagglutinin-neuraminidase(HN) of Newcastle disease virus(NDV) strain Changchun(NDVcc), the expression of HN gene in hepatoma cells(human HepG-2 and mouse H22 cells) infected with the recombinant adenovirus(Ad-HN) was identified by Western blot analysis and flow cytometry. Sialidase activity of NDVcc HN expressed by Ad-HN was assayed by the periodate-resorcinol method. The in vivo anti-tumor effects of NDVcc HN were evaluated in the H22 solid tumor model. Regional lymph nodes of the mouse model treated with Ad-HN were removed to harvest T lymphocytes and evaluating the specific cytotoxicity of cytotoxic T lymphocyte(CTL) and natural killer(NK) cells by an L-lactate dehydrogenase(LDH) assay, in the mean time, the secretion of cytokines was analyzed by enzyme linked immunosorbent assays(ELISA). The results show that NDVcc HN was effectively expressed by Ad-HN in HepG-2 and H22 cells. The sialidase activity assay showed that Ad-HN significantly reduced sialic acid level of the hepatoma cells compared with the cells infected the empty adenovirus vector(Ad-mock). When treated with Ad-HN, the growth of subcutaneous H22 primary tumors in C57BL/6 mice was suppressed, and the mean mice survival increased. In addition, the treatment of Ad-HN elicited strong NK and CTL responses, and high levels of Th1 cytokines, such as IL-2 and IFN-γ. In conclusion, NDVcc HN effectively elicits T cell-mediate anti-tumor cytotoxicity via sialidase activity and may be a novel strategy for cancer immunotherapy.
基金the 38th China Postdoctoral Science Foundation, No. 2005038055 the Scientific and Technological Research Projects of Liaoning Province, No. 2005225003-14the Natural Science Foundation of Liaoning Province, No. 20052204
文摘BACKGROUND: With developments of tissue engineering and genetic engineering, we aim to culture myoblasts, which are characterized by high purity, high quality and high production, for wide application in neural regeneration researches. OBJECTIVE: To modify traditional dissociation method in order to obtain myoblasts, which are characterized by high purity, high quality and high production, and explore the biological properties under in vitro culture. DESIGN: Observational study. SETTING: Basic Institute of Academy of Military Medical Sciences of Chinese PLA. MATERIALS: Four neonatal Wistar rats of 5 days old, both genders and mean body mass of 10 g were selected in this study. The main reagents and devices were detailed as follows: DMEM medium (Gibco Company), fetus bovine serum (FBS, Hycolne Company), collagenase Ⅱ(Sigma Company), trypsin (Sigma Company), dispase Ⅱ (Sigma Company), desmin antibody (Fuzhou Maixin Company), antibody Ⅱ and ABC kit (Wuhan Boster Biotechnology Company), desk centrifuge (KUBATO, Japan), and inverted phase contrast microscope (LEICA DMIRB, Germany). METHODS: The experiment was carried out in the Basic Institute of Academy of Military Medical Sciences of Chinese PLA from June to October 2006. Neonatal rats were sacrificed under sterile condition to obtain skeletal muscles of limbs, which were washed with cold PBS (containing benzylpenicillin and estreptomicina), and muscular tissue was sheared into pieces. Then, those muscular pieces were added with mixed digestive enzyme (containing 2 g/L collagenase Ⅱ + 5 g/L dispase Ⅱ + 0.28 g/L CaCl2) as twice volume as pieces, dealt with mechanical pipetting for 5 minutes and cultured in CO2 incubator for 10 minutes. The operation was done for three times and the muscular pieces were digested for 45 minutes in total. Moreover, cells were suspended again in order to obtain myoblasts from skeletal muscle of neonatal rats. In addition, myoblasts were purified with differential attachment technique and enzyme digestion so as to observe morphological characteristics and growth, draw growth curve, analyze surface structure under scanning electron microscope, and evaluate with Desmin immunohistochemical staining. MAIN OUTCOME MEASURES: Morphological characteristics and growth of myoblasts cultured in vitro. RESULTS: ① Growth of myoblasts of skeletal muscle: Primary cells had well growth, mature and differentiation. The positive rate of Desmin was 94% and purification of cells was ideal. Growth curve of cells demonstrated that myoblasts which were characterized by high purification started proliferation plentiful through transient growth lag phase (about at one or two days after inoculation). If myoblasts were not dealt with any interventions, they might become sarcotubule gradually at 3–5 days after proliferative phase. During this period, myoblasts maintained a monocaryon-bipolarity state under inverted phase contrast microscope. Furthermore, the growth of cells was the strongest and reproductive activity was the most powerful. This suggested that myotube started to form; in addition, muscle fiber of contractility might form under a well culturing condition. ② Immunocytochemical stain with desmin antibody: Interzonal fiber of desmin from myoblasts showed strongly positive reaction. Positive staining existed in cytoplasm had a high nucleus-cytoplasm ratio. However, myoblasts showed negative or mildly positive reaction. CONCLUSION: It is ideal for modified multi-enzymatic digestion and double purification method to dissociate and purify myoblasts of skeletal muscle; meanwhile, these two methods are both the effective ways to provide convenient conditions to obtain seed cells for neural regeneration researches.
基金This work is supported by Demonstration of Scientific and Technology Achievements Transform in Sichuan Province under Grant 2022ZHCG0036National Natural Science Foundation of China(62002047).
文摘Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.
基金Z.ZHENG is supported by the National Natural Science Foundation of China(No.61901033)the Natural Science Foundation of Beijing(No.L212031)+1 种基金X.Y.BAO is supported by the China Academy of Information and Communications Technology,Y.Z.HUANG is supported by the National Natural Science Foundation of China(No.61971474)the Beijing Nova Program(No.Z201100006820121)。
文摘In this paper,physical layer security techniques are investigated for cooperative multi-input multi-output(C-MIMO),which operates as an underlaid cognitive radio system that coexists with a primary user(PU).The underlaid secrecy paradigm is enabled by improving the secrecy rate towards the C-MIMO receiver and reducing the interference towards the PU.Such a communication model is especially suitable for implementing Industrial Internet of Things(IIoT)systems in the unlicensed spectrum,which can trade off spectral efficiency and information secrecy.To this end,we propose an eigenspace-adaptive precoding(EAP)method and formulate the secrecy rate optimization problem,which is subject to both the single device power constraint and the interference power constraint.This precoder design is enabled by decomposing the original optimization problem into eigenspace selection and power allocation sub-problems.Herein,the eigenvectors are adaptively selected by the transmitter according to the channel conditions of the underlaid users and the PUs.In addition,a simplified EAP method is proposed for large-dimensional C-MIMO transmission,exploiting the additional spatial degree of freedom for a low-complexity secrecy precoder design.Numerical results show that by transmitting signal and artificial noise in the properly selected eigenspace,C-MIMO can eliminate the secrecy outage and outperforms the fixed eigenspace precoding methods.Moreover,the proposed simplified EAP method for the large-dimensional C-MIMO can significantly improve the secrecy rate.
基金supported by National Natural Science Foundation of China(No.62071486)Natural Science Foundation on Frontier Leading Technology Basic Research Project of Jiangsu Province,China(BK20212001)Key Research and Development Program of Jiangsu Province Key Project and Topics,China(2019B010157001)。
文摘In this paper,we investigate the feasibility and performance of the covert communication with a spectrum sharing relay in the finite blocklength regime.Specifically,the relay opportunistically forwards the source's messages to the primary receiver or conveys the covert messages to its own receiver via the sharing spectrum,while the warden attempts to detect the transmission.First,we derive a lower bound on the covertness constraint,and the analytical expressions of both the primary average effective covert throughput(AECT)and sum AECT are presented by considering the overall decoding error performance.Then,we formulate two optimization problems to maximize the primary and sum AECT respectively by optimizing the blocklength and the transmit power at the source and the relay.Our examinations show that there exists an optimal blocklength to maximize the primary and sum AECT.Besides,it is revealed that,to maximize the primary AECT,the optimal transmit power of each hop increases as its channel quality deteriorates.Furthermore,in the optimization for maximizing the sum AECT,the optimal transmit power at the source equals to zero when the channel quality from relay to the secondary receiver is not weaker than that from relay to the primary receiver.
基金supported by the National Natural Science Foundation of China under Grant(no.62071486,no.61771487,no.62171464).
文摘In this paper,we investigate covert communications in data collected IoT with NOMA,where the paired sensor nodes S_(m) and S_(n) transmit covert messages to a legitimate receiver(Bob)in the presence of a Warden(Willie).To confuse the detection at Willie,an extra multi-antenna friendly jammer(Jammer)has been employed to transmit artificial noise(AN)with random power.Based on the CSI of Willie is available or not at Jammer,three AN transmission schemes,including null-space artificial noise(NAN),transmit antenna selection(TAS),and zeroforcing beamforming(ZFB),are proposed.Furthermore,the closed-form expressions of expected minimum detection error probability(EMDEP)and joint connection outage probability(JCOP)are derived to measure covertness and reliability,respectively.Finally,the maximum effective covert rate(ECR)is obtained with a given covertness constraint.The numerical results show that ZFB scheme has the best maximum ECR in the case of the number of antennas satisfies N>2,and the same maximum ECR can be achieved in ZFB and NAN schemes with N=2.Moreover,TAS scheme also can improve the maximum ECR compared with the benchmark scheme(i.e.,signal-antenna jammer).In addition,a proper NOMA node pairing can further improve the maximum ECR.
基金supported by the National High Technology Research and Development Program of China(Grant No.2006AA10A205)the National Key Technology Research and Development Program(Grant No. 2006BAD06A05)the National Key Program for Infectious Diseases of China(Grant No.2009ZX10004-103)
文摘Prophylactic DNA vaccines against the influenza virus are promising alternatives to conventional vaccines.In this study,we generated two candidate gene-based influenza vaccines encoding either the seasonal or pandemic hemagglutinin antigen(HA) from the strains A/New Caledonia/20/99(H1N1)(pV1A5) and A/California/04/2009(H1N1)(pVEH1) ,respectively.After verifying antigen expression,the immunogenicity of the vaccines delivered intramuscularly with electroporation was tested in a mouse model.Sera of immunized animals were tested in hemagglutination inhibition assays and by ELISA for the presence of HA-specific antibodies.HA-specific T-cells were also measured in IFN-γELISpot assays.The protective efficacy of the candidate influenza vaccines was evaluated by measuring mortality rates and body weight after a challenge with 100 LD50 of mouse-adapted A/New Caledonia/20/99(H1N1) .Mice immunized with either one of the two vaccines showed significantly higher T cell and humoral immune responses(P<0.05) than the pVAX1 control group.Additionally,the pV1A5 vaccine effectively protected the mice against a lethal homologous mouse-adapted virus challenge with a survival rate of 100%compared with a 40%survival rate in the pVEH1 vaccinated group(P<0.05) .Our study indicates that the seasonal influenza DNA vaccine completely protects against the homologous A/New Caledonia/20/99 virus(H1N1) ,while the pandemic influenza DNA vaccine only partially protects against this virus.
基金Supported by the National Science and Technology Major Projects for Major New Drugs Innovation and Development of China（No.2010ZX09401-305-14）, the National Natural Science Foundation of China（Nos.81072210, 81101140） and the Key Technologies R＆D Program of Jilin Province of China（Nos. 10ZDGG007, 201015166, 201101066）.
基金Supported by National High-Tech Research and Development Program of China(No.2007AA021004)the National Basic Research Program of China(No.2005CB523005)+2 种基金the National Natural Science Foundation of China(No.30771609)the National Science and Technology Major Project of China(Nos.2008ZX10004-015 2009ZX08006-002B)
文摘Hemagglutinin-neuramidinase(HN) is one of the most important surface structure proteins of the Newcastle disease virus(NDV). HN not only mediates receptor recognition but also possesses neuraminidase(NA) activity, which gives it the ability to cleave a component of those receptors, NAcneu. Previous studies have demonstrated that HN has interesting anti-neoplastic and immune-stimulating properties in mammalian species, including humans. To explore the application of the HN gene in cancer gene therapy, we constructed a Lewis lung carcinoma(LLC) solid tumor model using C57BL/6 mice. Mice were injected intratumorally with the recombinant adenovirus expressing HN gene(Ad-HN), and the effect of HN was explored by natural killer cell activity assay, cytotoxic lymphocyte activity assay, T cell subtype evaluation, and Th1/Th2 cytokines analysis. The results demonstrate that HN not only can elicit clonal expansion of both CD4+ and CD8+ T cell populations and cytotoxic T lymphocyte(CTL) and killer cell response, but also skews the immune response toward Th1. Thus, vaccination with Ad-HN may be a potential strategy for cancer gene therapy.
基金supported by the National Natural Science Foundation of China (22078314, 21878286, 21908216)Dalian Institute of Chemical Physics (DICPI202142, DICPI202006, DICPI201938, DICPZZBS201805, China)
文摘To the Editor:The current coronavirus disease-19(COVID-19)pandemic spurs the development of antiviral drugs for SARS-CoV-2,as the number of patients with viral infections continues to rise globally in the context of widespread vaccination.Targeting the interaction between the receptor binding domain(RBD)of SARS-CoV-2 spike protein and the host cell ACE2 is a promising therapeutic strategy to effectively inhibit viral entry.
