A PRIMARY OBSERVATION OF TPA EFFECT ON SSV-NIH3T3 CELLS IN SERUM-FREE MEDIUM

The effect of TPA, a potent tumor promoter, on SSV-NIH3T3 cells in serum-free medium was investigated. TPA stimulated DNA synthesis of SSV-NIH3T3 cells on the third day of culture in SFM. In SDS-PAGF of medium conditioned by TPA-treated SSV-NIH3T3 cells (in SFM+TPA), the amounts of four proteins of 31.0 Kd, 28.5 Kd, 25.5 Kd and 13.5 Kd strikingly increased over that of non-TPA-treated counterpart (in SFM). The PDGF-like activity was also detected in CM of SFM+TPA. When insulin and EGF were drown off the SFM+TPA (SFM-Ins-EGF+TPA), TPA lost its ability to stimulate DNA synthesis of SSV-NIH3T3 cells on the third day and SDS-PAGE of the conditioned medium showed that the amounts of the four proteins noted above grately reduced. However, cells in SFM-Ins-EGF+TPA were in almost the same growth condition as cells in complete SFM+TPA on the third day of culture. Results were discussed in the paper.

Novel sericin-based hepatocyte serum-free medium and sericin's effect on hepatocyte transcriptome

AIM To develop a novel hepatocyte serum-free medium based on sericin,and to explore the effect of sericin on the hepatocyte transcriptome.METHODS A controlled trial comparing novel serum-free medium and other media: C3 A cells were cultured in our novel serum-free medium,Hepato ZYME,complete medium(DMEM/F12 with 100 m L/L FBS),and DMEM/F12,andthen cell attachment,proliferation,and function as well as the biocompatibility of the media were assessed.A comparative study of serum-free media with or without 2 mg/m L sericin: the effect of sericin on C3 A growth was assessed by cell viability and proliferation,the effect of sericin on C3 A cell cycle distribution was determined by flow cytometry,and the effect of sericin on the C3 A transcriptome was assessed by gene-chip array and RT-q PCR.RESULTS More C3 A cells attached to the plate containing our serum-free medium than to those containing Hepato ZYME and DMEM/F12 at 24 h post-seeding.Both the viability and proliferation rate of C3 A cells in sericin-based serum-free medium were superior to those of cells in Hepato ZYME and DMEM/F12(P < 0.001).The content of albumin and urea in our serum-free medium was significantly higher than that in Hepato ZYME and DMEM/F12 throughout the whole culture period(P < 0.001) and was similar to that in complete medium at day 3,4,and 5.In part 2,cell viability and proliferation were greater in the presence of 2 mg/m L sericin(P < 0.001),as was the proportion of cells in S phase(16.21% ± 0.98% vs 12.61% ± 0.90%,P < 0.01).Gene-chip array analysis indicated that the expression of CCR6,EGFR,and FOS were up-regulated by 2 mg/m L sericin,and RT-q PCR revealed that the expression of CCR6,EGFR,FOS,AKT1,JNK1,NFk B1,MMP-9,MEK2,ERK1/2 and MYC was upregulated by 2 mg/m L sericin(P < 0.05).CONCLUSION We developed a novel hepatocyte serum-free medium.Sericin probably enhances cell attachment through the CCR6-Akt-JNK-NF-κB pathway and promotes cell proliferation through CCR6-mediated activation of the ERK1/2-MAPK pathway.

Some biological characteristics of hybridomas and parental myelomas cultivated in serum-free medium for long-term period

It has been developed in this laboratory that a serum-free medium, designated asDMI,is adaptive for long-term culture,freezing and resurgence in liquid nitrogen,and cloningof hybridoma and parental myelomas as well as for cell fusions.In this report,it is describedthat the myeloma cells grown in DMI for more than 3 months maintained their biological charac-teristics such as induction of aseites and subcutaneous somatic tumor in BALB/c mice and toler-ance toward 8-azaguanine,ete..However,the ability of the tumor cells to attach to glass wallwas decreased.The selecting assay of these cells in HAT medium(medium containing hypoxan-thine,aminopterin and thymidine)showed that the death time in DMI was similar to that in theconventional 15％ newborn calf serum-supplemented medium(RPS15).The hybridoma cellsadapted in DMI secrete monoclonal antibodies in quantities comparable to those produced inRPS15.

Cholesterol requirement for growth of rodent parental myeloma cells in serum-free medium

Cholesterol,a major lipid component of plasma membrane,is thoughtto have profound effects on the structure and function of cells.Mostanimal tis-sues are capable of synthesizing cholesterol de novo from acetate;however,thereare relatively few mammalian cells in vitro expressing an absolute requirement foran exogenous source of cholesterol.In this paper,it was shown that IR983F(983)rat myeloma cells and P3X63-AgS-U1(P3U1)and P3X63-Ag8.653(653)mousemy eloma cells which had been cultivated in serum-free medium for more than 6months required cholesterol in vitro for growth in serum-free medium.Optimalgrowth of P3U1,653 and 983 occurred in cholesterol concentration of 5,10 and15μg/ml,respectively.Moreover,it was demonstrated that the cholesterol couldbe replaced by human low density lipoprotein in a concentration of 10μg/ml butnot by mevalonic acid lactone.In contrast to the parental myeloma cells,hybridoma cells derived from the mouse myeloma cells which had been cultivatedin serum-free medium for more than 6 months did not require cholesterol.

Enrichment of breast cancer stem cells using a keratinocyte serum-free medium

Background Keratinoyte serum-free medium （K-SFM） is a defined medium used to support the growth of primary keratinocytes and embryonic stem cell. The aim of this research was to optimize enrichment of breast cancer stem cells （CSCs） using K-SFM. Methods＇ A K-SFM was used to enrich CSCs from two breast cancer cell lines and a primary culture of breast cancer. RPMI-1640 supplemented with 10% fetal calf serum （FCS） was used as a control. CSCs were identified with flow cytometry using CD44＋/CD24-as molecular markers. The expression of a variety of CSC markers （Oct-4, ABCG2, Nanog, N-cadherin, and E-cadherin） was analyzed with real-time PCR. Results Much higher percentage of CSCs was achieved with K-SFM： 17.3% for MCF-7 cells, 17.4% for SKBR-3, and 20.0% for primary breast cancer culture. Less than 1% CSC was achieved using RPMI-1640 supplemented with 10% FCS. In comparison to the CSCs obtained with RPMI-1640, CSCs in the K-SFM expressed higher levels of Oct-4, ABCG2, Nanog and N-cadherin, and lower level of E-cadherin. Conclusion K-SFM is an optimal culture medium to maintain and to enrich breast CSCs.

Review on the plastic instability of medium -Mn steels for identifying the formation mechanisms of Lüders and Portevin -Le Chatelier bands

Plastic instability,including both the discontinuous yielding and stress serrations,has been frequently observed during the tensile deformation of medium-Mn steels(MMnS)and has been intensively studied in recent years.Unfortunately,research results are controversial,and no consensus has been achieved regarding the topic.Here,we first summarize all the possible factors that affect the yielding and flow stress serrations in MMnS,including the morphology and stability of austenite,the feature of the phase interface,and the deformation parameters.Then,we propose a universal mechanism to explain the conflicting experimental results.We conclude that the discontinuous yielding can be attributed to the lack of mobile dislocation before deformation and the rapid dislocation multiplication at the beginning of plastic deformation.Meanwhile,the results show that the stress serrations are formed due to the pinning and depinning between dislocations and interstitial atoms in austenite.Strain-induced martensitic transformation,influenced by the mechanical stability of austenite grain and deformation parameters,should not be the intrinsic cause of plastic instability.However,it can intensify or weaken the discontinuous yielding and the stress serrations by affecting the mobility and density of dislocations,as well as the interaction between the interstitial atoms and dislocations in austenite grains.

A Dual-Cluster-Head Based Medium Access Control for Large-Scale UAV Ad-Hoc Networks

Unmanned Aerial Vehicle(UAV)ad hoc network has achieved significant growth for its flexibility,extensibility,and high deployability in recent years.The application of clustering scheme for UAV ad hoc network is imperative to enhance the performance of throughput and energy efficiency.In conventional clustering scheme,a single cluster head(CH)is always assigned in each cluster.However,this method has some weaknesses such as overload and premature death of CH when the number of UAVs increased.In order to solve this problem,we propose a dual-cluster-head based medium access control(DCHMAC)scheme for large-scale UAV networks.In DCHMAC,two CHs are elected to manage resource allocation and data forwarding cooperatively.Specifically,two CHs work on different channels.One of CH is used for intra-cluster communication and the other one is for inter-cluster communication.A Markov chain model is developed to analyse the throughput of the network.Simulation result shows that compared with FM-MAC(flying ad hoc networks multi-channel MAC,FM-MAC),DCHMAC improves the throughput by approximately 20%~50%and prolongs the network lifetime by approximately 40%.

THE INTERIOR TRANSMISSION EIGENVALUE PROBLEM FOR AN ANISOTROPIC MEDIUM BY A PARTIALLY COATED BOUNDARY

We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and possesses different transmission conditions.Using the variational method,we obtain the well posedness of the interior transmission problem,which plays an important role in the proof of the discreteness of eigenvalues.Then we achieve the existence of an infinite discrete set of transmission eigenvalues provided that n≡1,where a fourth order differential operator is applied.In the case of n■1,we show the discreteness of the transmission eigenvalues under restrictive assumptions by the analytic Fredholm theory and the T-coercive method.

Conditioned medium from human dental pulp stem cells treats spinal cord injury by inhibiting microglial pyroptosis

Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.

Simultaneously realizing thermal andelectromagnetic cloaking by multi-physicalnull medium

Simultaneously manipulating multiple physical fields plays an important role in the increasingly complex integrated systems,aerospace equipment,biochemical productions,etc.For on-chip systems with high integration level,the precise and efficient control of the propagation of electromagnetic waves and heat fluxes simultaneously is particularly important.In this study,we propose a graphical designing method(i.e.,thermal-electromagnetic surface transformation)based on thermal-electromagnetic null medium to simultaneously control the propagation of electromagnetic waves and thermal fields according to the pre-designed paths.A thermal-electromagnetic cloak,which can create a cloaking effect on both electromagnetic waves and thermal fields simultaneously,is designed by thermal-electromagnetic surface transformation and verified by both numerical simulations and experimental measurements.The thermal-electromagnetic surface transformation proposed in this study provides a new methodology for simultaneous controlling on electromagnetic and temperature fields,and may have significant applications in improving thermal-electromagnetic compatibility problem,protecting of thermal-electromagnetic sensitive components,and improving efficiency of energy usage for complex onchip systems.

Adenosine A_(2A)receptor blockade attenuates excitotoxicity in rat striatal medium spiny neurons during an ischemic-like insult

During brain ischemia,excitotoxicity and peri-infarct depolarization injuries occur and cause cerebral tissue damage.Indeed,anoxic depolarization,consisting of massive neuronal depolarization due to the loss of membrane ion gradients,occurs in vivo or in vitro during an energy failure.The neuromodulator adenosine is released in huge amounts during cerebral ischemia and exerts its effects by activating specific metabotropic receptors,namely:A_(1),A_(2A),A_(2B),and A_(3).The A_(2A)receptor subtype is highly expressed in striatal medium spiny neurons,which are particularly susceptible to ischemic damage.Evidence indicates that the A2Areceptors are upregulated in the rat striatum after stroke and the selective antagonist SCH58261 protects from exaggerated glutamate release within the first 4 hours from the insult and alleviates neurological impairment and histological injury in the following 24 hours.We recently added new knowledge to the mechanisms by which the adenosine A2Areceptor subtype participates in ischemia-induced neuronal death by performing patch-clamp recordings from medium spiny neurons in rat striatal brain slices exposed to oxygen and glucose deprivation.We demonstrated that the selective block of A2Areceptors by SCH58261 significantly reduced ionic imbalance and delayed the anoxic depolarization in medium spiny neurons during oxygen and glucose deprivation and that the mechanism involves voltage-gated K+channel modulation and a presynaptic inhibition of glutamate release by the A2Areceptor antagonist.The present review summarizes the latest findings in the literature about the possibility of developing selective ligands of A2Areceptors as advantageous therapeutic tools that may contribute to counteracting neurodegeneration after brain ischemia.

Improvement of Temperature Drop Model Parameters for 4200mm/3500mm Rolling of Baosteel Medium and Thick Plate

Based on the temperature situation during the rolling process of 4200 mm/3500 mm medium and thick plates at Baosteel,this article analyzes the influencing factors of temperature changes during the rolling process from the perspective of heat transfer theory and the temperature change law during the rolling process.The temperature loss during the four rolling processes is tracked on site,and the temperature drop model parameters during the rolling process of 4200mm/3500mm medium and thick plates at Baosteel are quantitatively provided.It is applied to actual rolling production and has achieved good results.

Isolation and Identification of Cancer Stem Cells from Human Osteosarcom by Serum-free Three-dimensional Culture Combined with Anticancer Drugs

The cancer stem cells(CSCs)from human osteosarcoma by serum-free three-dimensional culture combined with anticancer drugs were isolated and identified.The primary cells derived from human osteosarcoma were digested by trypsin to prepare a single-cell suspension,and mixed homogeneously into 1.2% alginate gel.Single-cell alginate gel was cultured with serum-free DMEM/F12 medium.Epirubicin(0.8μg/mL)was added to the medium to enrich CSCs.After cultured conventionally for 7 to 10 days,most of cells suspended in ...

INFLUENCE OF MIXING DEVICE ON SERUM-FREE CULTIVATION OF INSECT CELLS IN SPINNER FLASKS

A culture system was developed and successfully employed for the serum-free cultivation of Tn-5B1-4 (Tn5 ) insect cells. With our adaptation procedure, it was possible to obtain cells fully adapted to serum-free media in stationary T-flasks and then enable these adapted cells to grow well in spinner flasks immediately. The spinner "ask with special stirring design proved tO provide favorable culture environment that made it desirable for use in the serum-free cultivation of Tn5 cells even at low seeding density.

Comparative studies of serum-free media and detection techniques for <i>in vitro</i>drug sensitivity assessment of <i>Plasmodium falciparum</i>

Malaria continues to be a devastating disease. In a previous study, we formulated a chemically defined culture medium that is able to sustain the complete intraerythrocytic growth of Plasmodium falciparum. We tested the feasibility of using the medium (CDRPMI) as well as human serum-free media enriched with commercially available human-serum substitutes (GFSRPMI and ALBRPMI) to assess the drug sensitivity of P. falciparum, using chloroquine diphosphate (CQ) and dihydroartemisinin (DHART) as conventional antimalarial drugs. Growth inhibition was measured by four different methods: flow cytometry with SYBR Green I (FCM), microscopy (Giemsa method), enzymatic estimation of parasite lactate dehydrogenase (pLDH), and histidine-rich protein 2 (HRPII) determination. In drug sensitivity tests on asynchronous parasites cultured for 96 h in the presence of drugs, the dose-response curves were similar and differences in the 50% growth inhibition concentrations for the drugs, which were estimated by the four methods, were not statistically significant for the three culture media. The effect of the drugs on the growth of synchronous parasites at the ring stage was also assessed in micro-volume tests by three different methods of FCM: tracking fluorescent erythrocytes, schizont test, and merozoite test. Dose-response curves for the drugs were similar, and differences in the 50% growth inhibition concentrations were not statistically significant for CDRPMI and GFSRPMI. Thus CDRPMI as well as GFSRPMI and ALBRPMI can be similarly useful media for drug sensitivity testing of P. falciparum. The FCM, pLDH and HRPII estimations were fast and reliable detection methods, with FCM allowing schizont and merozoite tests to be performed with shorter periods of culture.

A novel binary effective medium model to describe the prepeak stressstrain relationship of combined bodies of rock-like material and rock

Combined bodies of rock-like material and rock are widely encountered in geotechnical engineering,such as tunnels and mines.The existing theoretical models describing the stress-strain relationship of a combined body lack a binary feature.Based on effective medium theory,this paper presents the governing equation of the“elastic modulus”for combined and single bodies under triaxial compressive tests.A binary effective medium model is then established.Based on the compressive experiment of concretegranite combined bodies,the feasibility of determining the stress threshold based on crack axial strain is discussed,and the model is verified.The model is further extended to coal-rock combined bodies of more diverse types,and the variation laws of the compressive mechanical parameters are then discussed.The results show that the fitting accuracy of the model with the experimental curves of the concretegranite combined bodies and various types of coal-rock combined bodies are over 95%.The crack axial strain method can replace the crack volumetric strain method,which clarifies the physical meanings of the model parameters.The variation laws of matrix parameters and crack parameters are discussed in depth and are expected to be more widely used in geotechnical engineering.

CLONAL PROLIFERATION AND LONG-TERM CULTURE OF MALIGNANT LYMPHOMA CELLS UNDER SERUM-FREE CULTURE CONDITIONS

We developed a serum-free culture system that promoted the growth of B cell colonies in peripheral blood, bone marrow, lymph nodes and cerebrospinal fluid (CSF) from 7 out of 8 patients with non-Hodgkin's lymphomas of B cell type. The culture cells were pretreated with or without galactose oxi-dase (GO) prior to plating. Colony growth was best supported with BCGF. A moderate increment was observed with rIL-3, as well as rIL-1β and even to a lesser degree, by rlL-2, while B cell stimulating factor-2 (rBCSF-2) and rlL-1β did not show significant activity. rGM-CSF and rG-CSF had little effect, while rM-CSF enhanced the formation of lymphoma colonies. The cells from different patients had different requirements for Staphylococcus aureus protein A and GO pretreatment. It reflected the differences in activation and differentiation status and surface properties of lymphoma cells from different patients. The cells from CSF of one patient were successfully maintained in serum-free culture medium supplemented with 10% BCGF or 5% PHA-LCM for more than 4 months. The long-term culture cells were EBV negative, phenotypically consistent with B cells and gene rearrangements for JH, Kappa and myc. This serum-free culture system allowed extensive analysis of the growth requirements for clonogenic precursors.

A Comparison Study on the δD Value of Polycyclic Aromatic Hydrocarbons in Hydrous Pyrolysate of Herbaceous Peat with Different Water Medium

To investigate the influence of diagenetic water media on the hydrogen isotopes of individual sedimentary aromatic compounds,a series of hydrous pyrolyses were conducted on herbaceous peat.Polycyclic aromatic hydrocarbons(PAHs)in hydrous pyrolysed samples and their hydrogen isotopic composition characteristics were studied.The aqueous medium demonstrated a significant influence on the hydrogen isotopic composition of the individual PAHs generated during pyrolysis.The results showed that the PAHs formed after pyrolysis in the presence of a saltwater medium with high δD value from a salt lake had a heavy hydrogen isotopic composition.The PAHs formed after pyrolysis in the presence of a fresh water medium with low δD value from a swamp had a light hydrogen isotopic composition.The difference in the average PAHδD value between the two hydrous experiments varied from -174‰ to -109‰,suggesting that the hydrogen isotopic composition of individual sedimentary PAHs can reflect the source of the diagenetic water medium.In addition,a comparative study found that the hydrogen isotopes of PAHs were superior to those of n-alkanes in the same sample for diagenetic water indications.The results indicated that the exchange of water-derived inorganic hydrogen and organic hydrogen was more intensive in freshwater experiments than in saltwater experiments.With an increase in the simulation temperature,the average δD value of PAHs generated in the hydrous simulation experiments showed an increasing trend,reflecting that the δD value of sedimentary PAHs formed with the participation of diagenetic water media was still closely related to the thermal maturity of organic matter.Comparative studies showed that theδD values of different types of organic compounds produced by hydrous pyrolysis of peat were in the order,PAHs>n-alkanes>methane.

Principle of subtraction ghost imaging in scattering medium

Scattering medium in light path will cause distortion of the light field,resulting in poor signal-to-noise ratio(SNR)of ghost imaging.The disturbance is usually eliminated by the method of pre-compensation.We deduce the intensity fluctuation correlation function of the ghost imaging with the disturbance of the scattering medium,which proves that the ghost image consists of two correlated results:the image of scattering medium and the target object.The effect of the scattering medium can be eliminated by subtracting the correlated result between the light field after the scattering medium and the reference light from ghost image,which verifies the theoretical results.Our research may provide a new idea of ghost imaging in harsh environment.

Flow and heat transfer of a nanofluid through a porous medium due to stretching/shrinking sheet with suction,magnetic field and thermal radiation

This study investigates the suction and magnetic field effects on the two-dimensional nanofluid flow through a stretching/shrinking sheet at the stagnation point in the porous medium with thermal radiation.The governing partial differential equations(PDEs)are converted into ordinary differential equations(ODEs)using the similarity transformation.The resulting ODEs are then solved numerically by using the bvp4c solver in MATLAB software.It was found that dual solutions exist for the shrinking parameter values up to a certain range.The numerical results obtained are compared,and the comparison showed a good agreement with the existing results in the literature.The governing parameters’effect on the velocity,temperature and nanoparticle fraction fields as well as the skin friction coefficient,the local Nusselt number and the Sherwood number are represented graphically and analyzed.The variation of the velocity,temperature and concentration increase with the increase in the suction and magnetic field parameters.It seems that the thermal radiation effect has increased the local Sherwood number while the local Nusselt number is reduced with it.