In this study,we have explored the use of water as a non-solvent for tuning the microstructure of poly-benzimidazole(PBI)membranes,which are potential separators for lithium metal batteries(LMBs).The traditional metho...In this study,we have explored the use of water as a non-solvent for tuning the microstructure of poly-benzimidazole(PBI)membranes,which are potential separators for lithium metal batteries(LMBs).The traditional method for membrane synthesis called nonsolvent-induced phase separation(NIPS),usually relies on hazardous and costly organic non-solvents.By dissolving sodium chloride(Nacl)in water,we could adjust the water ionic potency and the exchange speed of the non-solvent with the DMAC solution to change the micropore structure of the PBI membrane.With increasing Nacl concentration,the micro-pores in the PBI membrane transitioned from finger-like to sponge-like morphology.Compared to com-mercial separators like the Celgard separator,the PBI membrane with sponge-like micropores exhibited better regulation of lithium deposition and improved Li^(+) transportation capability due to its good wetta-bility with the electrolyte.Consequently,the PBI membrane-based Li/Li symmetric cell and Li/LiFePO_(4) full cell demonstrated superior performance compared to the Celgard-based ones.This research proposes an eco-friendly and scalable synthetic approach for fabricating commercial separators for LMBs,addressing the issue of lithium dendrite growth and improving overall battery safety and performance.展开更多
Objective:To evaluate the additive action of ginger starch on the antifungal activity of honey against Candida albicans(C.albicans).Methods:C.albicans was used to determine the minimum inhibitory concentration(MIC)of ...Objective:To evaluate the additive action of ginger starch on the antifungal activity of honey against Candida albicans(C.albicans).Methods:C.albicans was used to determine the minimum inhibitory concentration(MIC)of four varieties of Algerian honey.Lower concentrations of honey than the MIC were incubated with a set of concentrations of starch and then added to media to detennine the minimum additive inhibitory concentration(MAIC).Results:The MIC for the four varieties of honey without starch against C.albicans ranged between 38%and 42%(v/v).When starch was incubated with honey and then added to media,a MIC drop was noticed with each variety.MAIC of the four varieties ranged between 32%honey(v/v)with 4%starch and 36%honey(v/v) with 2%starch.Conclusions:The use of ginger starch allows honey benefit and will constitute an alternative way against the resistance to antifungal agents.展开更多
Dimerization is an effective strategy for designing antimicrobial peptides that combine the advantages of different native peptides. In this study, we explored the effects of different linker amino acids, including le...Dimerization is an effective strategy for designing antimicrobial peptides that combine the advantages of different native peptides. In this study, we explored the effects of different linker amino acids, including leucine, proline and aminocaproic acid, on the anticancer, antimicrobial and hemolytic activities of the heteromeric antimicrobial peptides AM-1, AM-2, and AM-3. Proline and aminocaproic acid are ideal linkers for increasing the potency and selectivity of heteromeric antimicrobial peptides. The results of MD simulations provided a rationalization for this observation. Both AM-2, which had a proline linker,and AM-3, which had an aminocaproic acid linker, adopted a compact conformation in water and a bent conformation in membranes. This change in the flexible structures of AM-2 and AM-3 could have resulted in decreased binding of these peptides to zwitterionic lipid bilayers and increased damage to mixed lipid bilayers containing acidic phospholipids. In short, these findings obtained via assessing the effects of linker amino acids will contribute to the design of ideal heteromeric antimicrobial peptides with high selectivity and potency.展开更多
Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use ...Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics.In order to overcome the resistance problem and to safely use antibiotics,the correct measurement of potency and bioactivity of antibiotics is essential.Microbiological assay and high performance liquid chromatography（HPLC） method are used to quantify the potency of antibiotics.HPLC method is commonly used for the quantification of potency of antibiotics,but unable to determine the bioactivity;whereas microbiological assay estimates both potency and bioactivity of antibiotics.Additionally,bioassay is used to estimate the effective dose against antibiotic resistant microbes.Simultaneously,microbiological assay addresses the several parameters such as minimal inhibitory concentration（MIC）,minimum bactericidal concentration（MBC）,mutation prevention concentration（MPC） and critical concentration（Ccr） which are used to describe the potency in a more informative way.Microbiological assay is a simple,sensitive,precise and cost effective method which gives reproducible results similar to HPLC.However,the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.展开更多
Ebola virus infection causes severe hemorrhagic fever in human and non-human primates with high mortality. Viral entry/infection is initiated by binding of glycoprotein GP protein on Ebola virion to host cells, follow...Ebola virus infection causes severe hemorrhagic fever in human and non-human primates with high mortality. Viral entry/infection is initiated by binding of glycoprotein GP protein on Ebola virion to host cells, followed by fusion of virus-cell membrane also mediated by GP. Using an human immunodeficiency virus (HIV)-based pseudotyping system, the roles of 41 Ebola GP1 residues in the receptor-binding domain in viral entry were studied by alanine scanning substitutions. We identified that four residues appear to be involved in protein folding/structure and four residues are important for viral entry. An improved entry interference assay was developed and used to study the role of these residues that are important for viral entry. It was found that R64 and K95 are involved in receptor binding. In contrast, some residues such as I170 are important for viral entry, but do not play a major role in receptor binding as indicated by entry interference assay and/or protein binding data, suggesting that these residues are involved in post-binding steps of viral entry. Furthermore, our results also suggested that Ebola and Marburg viruses share a common cellular molecule for entry.展开更多
AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion ...AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion tags （glutathione S-transferase, GST; thioredoxin, Trx; maltose-binding protein, MBP）, which preferably contributes to increasing solubility and to facilitating the proper folding of heteroprotein, were used to acquire the soluble and functional expression of RBD protein in Escherichia coli （BL21（DE3） and Rosetta-gamiB （DE3） strains）. The receptor binding ability of the purified soluble RBD protein was then detected by ELISA and flow cytometry assay. RESULTS： RBD of SARS-Cov spike protein was expressed as inclusion body when fused as TrxA tag form in both BL21 （DE3） and Rosetta-gamiB （DE3） under many different cultures and induction conditions. And there was no visible expression band on SDS-PAGE when RBD was expressed as MBP tagged form. Only GST tagged RBD was soluble expressed in BL21（DE3）, and the protein was purified by AKTA Prime Chromatography system. The ELISA data showed that GST.RBD antigen had positive reaction with anti-RBD mouse monoclonal antibody 1A5. Further flow cytometry assay demonstrated the high efficiency of RBD＇s binding ability to ACE2 （angiotensin-converting enzyme 2） positive Vero E6 cell. And ACE2 was proved as a cellular receptor that meditated an initial-affinity interaction with SARS-Cov spike protein. The geometrical mean of GST and GST.RBD binding to Vero E6 cells were 77.08 and 352.73 respectively. CONCLUSION： In this paper, we get sufficient soluble N terminal GST tagged RBD protein expressed in EcoliBL21 （DE3）; data from ELISA and flow cytometry assay demonstrate that the recombinant protein is functional and binding to ACE2 positive Vero E6 cell efficiently. And the recombinant RBD derived from E.coli can be used to developing subunit vaccine to block S protein binding with receptor and to neutralizing SARS-Cov infection.展开更多
In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most...In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most effective strategy to solve the pandemic crisis.SARS-CoV-2 infects the host by binding to the cellular receptor angiotensin converting enzyme 2(ACE2)via the receptor-binding domain(RBD)of the surface spike(S)glycoprotein.In this study,a candidate vaccine based on a RBD recombinant subunit was prepared by means of a novel glycoengineered yeast Pichia pastoris expression system with characteristics of glycosylation modification similar to those of mammalian cells.The candidate vaccine effectively stimulated mice to produce high-titer anti-RBD specific antibody.Furthermore,the specific antibody titer and virus-neutralizing antibody(NAb)titer induced by the vaccine were increased significantly by the combination of the double adjuvants Al(OH)_(3) and CpG.Our results showed that the virus-NAb lasted for more than six months in mice.To summarize,we have obtained a SARS-CoV-2 vaccine based on the RBD of the S glycoprotein expressed in glycoengineered Pichia pastoris,which stimulates neutralizing and protective antibody responses.A technical route for fucose-free complex-type N-glycosylation modified recombinant subunit vaccine preparation has been established.展开更多
The aim of the paper was to determine benz(a)-pyrene in the preparations containing humates and study the benz(a)pyrene biological potency for the agricultural plants. The research methodology included the determinati...The aim of the paper was to determine benz(a)-pyrene in the preparations containing humates and study the benz(a)pyrene biological potency for the agricultural plants. The research methodology included the determination of the dependencies in the system “substance concentration (dose)—effect on the plant”. Concentrations of benz(a)pyrene in 12 samples of the humates preparations and fertilizers based on their trademarks “Irkutsk humates”, obtained from brown coal, varied in the range from 0.3 to 50 mcg/kg, which creates no soil contamination in conditions of the use of preparations. Between contents of benz(a)pyrene and humates there is a correlation (rxy = 0.95;α = 0.05). It is ascertained that the effects of stimulation and/or inhibition of the growth and yield of agricultural plants depend on the concentration of benz(a)pyrene and the method of plant processing. Optimal concentrations of benz(a)pyrene were 150-200 ng/dm3 for preplant way of processing of potato tubers, 3-10 ng/dm3—for top dressing (spraying) and 0.1-0.3 ng/dm3—for dressing under the roots (hydroponic). The obtained results allowed us to offer one of the possible mechanisms of biological potency of humates as the plant growth stimulants, and also a way testing of the preparations by screening of their benz(a)pyrene content.展开更多
Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed ...Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed methods".Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.展开更多
Light-emitting diodes (LEDs) can be used as an energy efficient alternative to high-pressure sodium (HPS), which have historically been the standard for supplemental lighting in cannabis cultivation. However, there is...Light-emitting diodes (LEDs) can be used as an energy efficient alternative to high-pressure sodium (HPS), which have historically been the standard for supplemental lighting in cannabis cultivation. However, there is a lack of scientific understanding in the cannabis industry regarding plant physiology, which has resulted in the adoption of cannabis cultivation methods based on hearsay rather than scientific research. The goals of this study were to 1) compare LED lighting options that are commonly used in the cannabis industry and 2) compare the top performing LED light with an industry standard HPS light. Specifically, three LED lights were compared (California Light Works ((SolarSystem 1100), BIOS Lighting (Icarus Gi2), and Fluence Bioengineering (now Fluence by Osram) (SPYDR xPLUS)), based on light distribution, leaf temperature, and photosynthetic performance indices. The LED versus HPS comparison was based on light response curves measured at photosynthetic photon flux densities (PPFD) of (0, 100, 200, 300, 400, 500, 750, 1000, 1250, 1500, 1750 and 2000 μmol<span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>m<sup><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:nowrap;">∙</span>s<sup><span style="white-space:nowrap;">−</span>1</sup>), carbon assimilation rates (<em>A</em>) μmol CO<sub>2</sub> m<sup><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>s<sup><span style="white-space:nowrap;">−</span>1</sup> using a LiCor-6800 and resulting cannabinoid potency (THCA). The SPYDR xPLUS-Fluence by Osram had the highest performing LED light used in the LED comparison. At the suggested distance from bulb to canopy in the HPS versus LED comparison (6 inches for LEDs and 4 ft for HPS), carbon assimilation rates displayed a 142% percent increase in plants grown under LED vs. HPS with average photon flux densities of 795 and 298 μmol<span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>m<sup><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>s<sup><span style="white-space:nowrap;">−</span>1</sup> for LED and HPS, respectively. All cultivars of<em> Cannabis sativa </em>L. showed increased cannabinoid potency when grown under LED illumination. The results of this study provide further insight regarding the selection of supplemental light to achieve maximum productivity of <em>Cannabis sativa</em> L.展开更多
Surface plasmon resonance(SPR) systems are widely used for detailed characterization of antibody activities including antigen and Fc-receptor binding. During the later stages of development, where the focus is to ensu...Surface plasmon resonance(SPR) systems are widely used for detailed characterization of antibody activities including antigen and Fc-receptor binding. During the later stages of development, where the focus is to ensure that established critical quality attributes(CQAs) are maintained during cell culture,purification and formulation processes, analysis is simplified, and relative potencies are often determined. Here, simulation of binding data revealed that relative potency values, determined via parallel line analysis(PLA) and half maximal effective concentration(EC50) analysis accurately reflect changes in active concentration only if binding kinetics remain unchanged. Changes in the association rate constant shifted dose response curves, and therefore relative potencies, in the same way as changes in analyte concentration do. However, for interactions characterized by stable binding, changes in the dissociation rate constant did not result in any shift, suggesting that this type of change may go unnoticed in the dose response curve. Thus, EC50 and PLA analyses of dose response curves obtained with an anti-TNF-α antibody were complemented with the Biacore functionality for sensorgram comparison analysis, whereby changes in antigen and Fc-receptor binding profiles could be detected. Next, analysis of temperature stressed TNF-α antibody revealed that calibration free concentration analysis(CFCA) data correlated perfectly with relative potency values. Together, these results demonstrate that combinations of SPR based dose response curves, sensorgram comparison and CFCA can be used to strengthen the confidence in relative potency assessments, and suggest that SPR can potentially be used as a surrogate potency assay in the quality control of biotherapeutic medicines.展开更多
Cardiovascular complications of patients with type 2 diabetes mellitus(T2DM)threaten the health and life of numerous individuals.Recently,growth factor receptor-binding protein 10(GRB10)was found to play a pivotal rol...Cardiovascular complications of patients with type 2 diabetes mellitus(T2DM)threaten the health and life of numerous individuals.Recently,growth factor receptor-binding protein 10(GRB10)was found to play a pivotal role in vascular complications of T2DM,which participates in the regulation of lipid metabolism of T2DM patients.The genetic variation of GRB10 rs1800504 is closely related to the risk of coronary heart disease in patients with T2DM.The development of GRB10 as a key mediator in the association of lipid metabolism with cardiovascular complications in T2DM is detailed in and may provide new potential concerns for the study of cardiovascular complications in T2DM patients.展开更多
Gastric parietal cells are important in acid secretion, but it is unclear which cells throughout the gastric gland have the highest secretion potency. Here, we used immunohistochemical methods with anti-H+, K+-ATPase,...Gastric parietal cells are important in acid secretion, but it is unclear which cells throughout the gastric gland have the highest secretion potency. Here, we used immunohistochemical methods with anti-H+, K+-ATPase, phosphoryl ezrin and CD44 antibodies to study the distribution of gastric acid secretion activity. Stomach tissues from freely fed and starved rats were cryofixed for light microscopy or fixed by high-pressure freezing for electron microscopy. Parietal cells from freely fed animals corresponded to the active secretion phase and to the inactive resting phase from starved rats. Anti-H+, K+-ATPase and anti-phosphoryl ezrin labeling were observed on the membrane of the intracellular canaliculi and the tubulovesicle from freely fed rats, while cells from starved animals showed weak labeling with anti-phosphoryl ezrin antibody staining. Morphometrical analysis at the electron microscopic level was performed on active and inactive acid secretory phases between the upper and base regions of the gland. H+, K+-ATPase and CD44 were distributed on both sites of the microvillous and tubulovesicle membrane in the same cells, but phosphoryl ezrin localized predominantly on the microvillous membrane in active cells of the glandular neck and upper base. Therefore, the highest secreting potency appeared to be in cells of the glandular neck and upper base.展开更多
The treatment of type 1 diabetes is mainly dependent on insulin therapy and current formulated insulin formulations are used for its control all over the world. The presented study was designed to evaluate the potency...The treatment of type 1 diabetes is mainly dependent on insulin therapy and current formulated insulin formulations are used for its control all over the world. The presented study was designed to evaluate the potency of extracted, purified and formulated insulin from the pancreatic organs of the Sudanese beef cattle. Twenty healthy rabbits were used to conduct the study following subcutaneous administration of the sample insulin, to determine the hypoglycemic effect and to analyze the potency of the testing insulin by the hypoglycemic seizure method, blood sugar method and glucose enzymatic colorimetric test (GOD-PAP) respectively. The potency of the injected insulin samples was estimated by comparing the variation in blood glucose levels produced in the treated animals with that produced by a standard insulin preparation under the suitable conditions of the blood sugar method. The results revealed that the potency of the testing beef insulin samples was slightly higher (i.e., 2.2 USP units/ml, 9%) compared to the standard and assumed potency of the prepared insulin preparations (i.e., 1-2 USP units/ml) which indicated that the solvents and diluents used to prepare the assay dilution might be of higher potency and must be diluted to such an extent that the testing insulin potency must be compatible with the standard dilutions. Furthermore, to determine the choice of an assay to analyze the potency of insulin preparations, not only the accuracy of the result but also the purpose for which the test is to be used and the time limit must be taken into consideration.展开更多
AIM:To describe confidence interval calculation for antidotal potency ratios using bootstrap method.METHODS:We can easily adapt the nonparametric bootstrap method which was invented by Efron to construct confidence in...AIM:To describe confidence interval calculation for antidotal potency ratios using bootstrap method.METHODS:We can easily adapt the nonparametric bootstrap method which was invented by Efron to construct confidence intervals in such situations like this.The bootstrap method is a resampling method in which the bootstrap samples are obtained by resampling from the original sample.RESULTS:The described confidence interval calculation using bootstrap method does not require the sampling distribution antidotal potency ratio.This can serve as a substantial help for toxicologists,who are directed to employ the Dixon up-and-down method with the application of lower number of animals to determine lethal dose 50 values for characterizing the investigated toxic molecules and eventually for characterizing the antidotal protections by the test antidotal systems.CONCLUSION:The described method can serve as a useful tool in various other applications.Simplicity ofthe method makes it easier to do the calculation using most of the programming software packages.展开更多
Objective Both the 2, 6 linkage and its topology on target cells are critical for the recognition by human influenza virus. The binding preference of avian flu virus H5N1 HA to the 2, 3-1inked sialylated glycans is co...Objective Both the 2, 6 linkage and its topology on target cells are critical for the recognition by human influenza virus. The binding preference of avian flu virus H5N1 HA to the 2, 3-1inked sialylated glycans is considered the major factor limiting its efficient infection and transmission in humans. To monitor potential adaptation of H5N1 virus in human population, the surveillance of receptor-binding specificity was undertaken in China. Methods The binding specificity of 32 human H5N1 virus strains isolated from 2003 to 2009 was tested by 2, 3-specific sialidase-treated chicken red blood cell （CRBC） agglutination assay and a solid-phase direct binding assay with synthetic sialylglycopolymers. Results Dual binding preference to 2, 3 and 2, 6-glycans were found in two strains： A/Guangdong/1/06 （A/GD/1/06） and A/Guangxi/1/08 （A/GX/1/08）. Though minor effect of short-2, 6-binding was detected in A/GX/1/08 at a low virus titer, both showed high affinity to the oligosaccharide at a high load. Notably both are of the long-2, 6-recognition, with the same topology as that of human H1N1 and H3N2 viruses. Conclusion The findings suggest that human H5N1 virus in China likely acquired the potential human-adaptation ability. Further research and surveillance on receptor-binding specificity of H5N1 viruses are required.展开更多
Effects of different enucleation methods on developmental potency of pig handmade clone（HMC）reconstructed embryo was investigated in the paper.We compared enucleation efficiency of blind cut method,first polar body...Effects of different enucleation methods on developmental potency of pig handmade clone（HMC）reconstructed embryo was investigated in the paper.We compared enucleation efficiency of blind cut method,first polar body（Pb1）positioning method and demecolcine（DM）assisted enucleation,as well as their effects on development of HMC reconstructed embryos.The results showed that overall enucleation efficiency of Pb1 positioning method was significantly higher than that of blind cut method（P〈0.05）.The protuberance rate and overall enucleation efficiency of 0.4μg/mL DM treated group for 60 min was significantly higher than that of other concentrations and time treatment groups（P〈0.05）.For effects on development of HMC reconstructed embryos,there was no significant difference between DM-assisted enucleation and Pb1 positioning method.In conclusion,appropriate addition of DM could enhance enucleation efficiency of HMC,which had no significant influence on developmental potency of reconstructed embryos.展开更多
Developmental potency of primitive and embryonic ectoderm cells from 4.50-day to 6.25-day post-coitum (p.c.) mouse embryos and primordial germ cells from 12.50-day p.c.male genital ridges of fetal mice were studied by...Developmental potency of primitive and embryonic ectoderm cells from 4.50-day to 6.25-day post-coitum (p.c.) mouse embryos and primordial germ cells from 12.50-day p.c.male genital ridges of fetal mice were studied by direct introducing them into 3.50-day p.c.blastocysts.Sixteen (61.5) overt chimaeras out of 26(50%) offsprings were obtained after transfer of 52 blastocysts injected with 4.50-day primitive ectoderm cells;four (16.0%) overt chimaeras were obtained out of 25 (51.0%) offsprings with 4.75-day primitive ectoderm cells from 49 transferred blastocysts.However,no overt chimaera was obtained with either 5.25-day or 6.25-day embryonic ectoderm cells or 12.50-day male primordial germ cells.GPI analysis of mid-gestation conceptuses developed from injected blastocysts showedthat 5.25-day embryonic ectoderm cells could only contributed to yolk sac of conceptus.Results suggested that implantation acts as a trigger for the determination of primitive ectoderm cells,and their developmental potency becomes limited within a short period of time in normal development.展开更多
The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evalu...The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evaluation. Mice were divided into groups for being immunized with corresponding serially diluted experimental SARS virus inactivated vaccine. And the rabbits were immunized with undiluted vaccine. Challenge assay was conducted with a heterologous SARS virus. And the neutralization antibody was determined with plaque reduction neutralization test (PRNT), to which the neutralization antibody in the convalescent serum of SARS patients was compared. The experimental vaccine viral strains were proved to be suitable for manufacturing the vaccine. Mice immunized by vaccines of serial dilutions were able to elicit neutralizing antibody. The antibody titer from mice immunized with the undiluted vaccine could reach up to 1∶495.2, while those of rabbits immunized with the undiluted vaccine could reach a GMT of 55.0-79.9. The capability of the antibody to neutralize the virus from Guangdong is more efficient than that from Beijing. The GMT of neutralizing antibody in SARS convalescents living in south and north China ranged from 50.12 to 54.95, and the titers of convalescents from north China were higher than those from south China. Mice and rabbits used as the model for evaluation of potency are of sensitivity, and the test is of reproducibility. The candidate challenge viral strains showed a relatively consistent effect on evaluating antibodies produced by various batches and different vaccine-source strains, hence they can be used to evaluate potency of the vaccine. The method for testing the vaccine potency and the evaluation standard was established preliminarily.展开更多
基金supported by the funding from the Natural Science Foundation of China (22105129)the Guangdong Basic and Applied Basic Research Foundation (2022A1515011048,2022A1515010670)the Science and Technology Innovation Commission of Shenzhen (JCYJ20200109105618137,20200812112006001)
文摘In this study,we have explored the use of water as a non-solvent for tuning the microstructure of poly-benzimidazole(PBI)membranes,which are potential separators for lithium metal batteries(LMBs).The traditional method for membrane synthesis called nonsolvent-induced phase separation(NIPS),usually relies on hazardous and costly organic non-solvents.By dissolving sodium chloride(Nacl)in water,we could adjust the water ionic potency and the exchange speed of the non-solvent with the DMAC solution to change the micropore structure of the PBI membrane.With increasing Nacl concentration,the micro-pores in the PBI membrane transitioned from finger-like to sponge-like morphology.Compared to com-mercial separators like the Celgard separator,the PBI membrane with sponge-like micropores exhibited better regulation of lithium deposition and improved Li^(+) transportation capability due to its good wetta-bility with the electrolyte.Consequently,the PBI membrane-based Li/Li symmetric cell and Li/LiFePO_(4) full cell demonstrated superior performance compared to the Celgard-based ones.This research proposes an eco-friendly and scalable synthetic approach for fabricating commercial separators for LMBs,addressing the issue of lithium dendrite growth and improving overall battery safety and performance.
基金financially supported by project CNEPRU,Institute of Veterinary Sciences.University Ibn-Khaldoun(TIARET).Algeria(grant No.F0232009/0009)
文摘Objective:To evaluate the additive action of ginger starch on the antifungal activity of honey against Candida albicans(C.albicans).Methods:C.albicans was used to determine the minimum inhibitory concentration(MIC)of four varieties of Algerian honey.Lower concentrations of honey than the MIC were incubated with a set of concentrations of starch and then added to media to detennine the minimum additive inhibitory concentration(MAIC).Results:The MIC for the four varieties of honey without starch against C.albicans ranged between 38%and 42%(v/v).When starch was incubated with honey and then added to media,a MIC drop was noticed with each variety.MAIC of the four varieties ranged between 32%honey(v/v)with 4%starch and 36%honey(v/v) with 2%starch.Conclusions:The use of ginger starch allows honey benefit and will constitute an alternative way against the resistance to antifungal agents.
基金the National Natural Science Foundation of China(Nos. 81773566, 21602092, 81473095)the Fundamental Research Funds for the Central Universities(Nos. lzujbky-2017-134, lzujbky-2017-120, lzujbky-2016-21)
文摘Dimerization is an effective strategy for designing antimicrobial peptides that combine the advantages of different native peptides. In this study, we explored the effects of different linker amino acids, including leucine, proline and aminocaproic acid, on the anticancer, antimicrobial and hemolytic activities of the heteromeric antimicrobial peptides AM-1, AM-2, and AM-3. Proline and aminocaproic acid are ideal linkers for increasing the potency and selectivity of heteromeric antimicrobial peptides. The results of MD simulations provided a rationalization for this observation. Both AM-2, which had a proline linker,and AM-3, which had an aminocaproic acid linker, adopted a compact conformation in water and a bent conformation in membranes. This change in the flexible structures of AM-2 and AM-3 could have resulted in decreased binding of these peptides to zwitterionic lipid bilayers and increased damage to mixed lipid bilayers containing acidic phospholipids. In short, these findings obtained via assessing the effects of linker amino acids will contribute to the design of ideal heteromeric antimicrobial peptides with high selectivity and potency.
文摘Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics.In order to overcome the resistance problem and to safely use antibiotics,the correct measurement of potency and bioactivity of antibiotics is essential.Microbiological assay and high performance liquid chromatography（HPLC） method are used to quantify the potency of antibiotics.HPLC method is commonly used for the quantification of potency of antibiotics,but unable to determine the bioactivity;whereas microbiological assay estimates both potency and bioactivity of antibiotics.Additionally,bioassay is used to estimate the effective dose against antibiotic resistant microbes.Simultaneously,microbiological assay addresses the several parameters such as minimal inhibitory concentration（MIC）,minimum bactericidal concentration（MBC）,mutation prevention concentration（MPC） and critical concentration（Ccr） which are used to describe the potency in a more informative way.Microbiological assay is a simple,sensitive,precise and cost effective method which gives reproducible results similar to HPLC.However,the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.
基金National Institutes of Health Grant (AI059570 and AI077767)
文摘Ebola virus infection causes severe hemorrhagic fever in human and non-human primates with high mortality. Viral entry/infection is initiated by binding of glycoprotein GP protein on Ebola virion to host cells, followed by fusion of virus-cell membrane also mediated by GP. Using an human immunodeficiency virus (HIV)-based pseudotyping system, the roles of 41 Ebola GP1 residues in the receptor-binding domain in viral entry were studied by alanine scanning substitutions. We identified that four residues appear to be involved in protein folding/structure and four residues are important for viral entry. An improved entry interference assay was developed and used to study the role of these residues that are important for viral entry. It was found that R64 and K95 are involved in receptor binding. In contrast, some residues such as I170 are important for viral entry, but do not play a major role in receptor binding as indicated by entry interference assay and/or protein binding data, suggesting that these residues are involved in post-binding steps of viral entry. Furthermore, our results also suggested that Ebola and Marburg viruses share a common cellular molecule for entry.
文摘AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion tags （glutathione S-transferase, GST; thioredoxin, Trx; maltose-binding protein, MBP）, which preferably contributes to increasing solubility and to facilitating the proper folding of heteroprotein, were used to acquire the soluble and functional expression of RBD protein in Escherichia coli （BL21（DE3） and Rosetta-gamiB （DE3） strains）. The receptor binding ability of the purified soluble RBD protein was then detected by ELISA and flow cytometry assay. RESULTS： RBD of SARS-Cov spike protein was expressed as inclusion body when fused as TrxA tag form in both BL21 （DE3） and Rosetta-gamiB （DE3） under many different cultures and induction conditions. And there was no visible expression band on SDS-PAGE when RBD was expressed as MBP tagged form. Only GST tagged RBD was soluble expressed in BL21（DE3）, and the protein was purified by AKTA Prime Chromatography system. The ELISA data showed that GST.RBD antigen had positive reaction with anti-RBD mouse monoclonal antibody 1A5. Further flow cytometry assay demonstrated the high efficiency of RBD＇s binding ability to ACE2 （angiotensin-converting enzyme 2） positive Vero E6 cell. And ACE2 was proved as a cellular receptor that meditated an initial-affinity interaction with SARS-Cov spike protein. The geometrical mean of GST and GST.RBD binding to Vero E6 cells were 77.08 and 352.73 respectively. CONCLUSION： In this paper, we get sufficient soluble N terminal GST tagged RBD protein expressed in EcoliBL21 （DE3）; data from ELISA and flow cytometry assay demonstrate that the recombinant protein is functional and binding to ACE2 positive Vero E6 cell efficiently. And the recombinant RBD derived from E.coli can be used to developing subunit vaccine to block S protein binding with receptor and to neutralizing SARS-Cov infection.
基金supported by the National Key Research and Development Program of China (2020YFC0841400-008)the National Science and Technology Major Projects(2018ZX09711003-013-002)the National Natural Science Foundation of China (81673339 and 81773619)
文摘In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most effective strategy to solve the pandemic crisis.SARS-CoV-2 infects the host by binding to the cellular receptor angiotensin converting enzyme 2(ACE2)via the receptor-binding domain(RBD)of the surface spike(S)glycoprotein.In this study,a candidate vaccine based on a RBD recombinant subunit was prepared by means of a novel glycoengineered yeast Pichia pastoris expression system with characteristics of glycosylation modification similar to those of mammalian cells.The candidate vaccine effectively stimulated mice to produce high-titer anti-RBD specific antibody.Furthermore,the specific antibody titer and virus-neutralizing antibody(NAb)titer induced by the vaccine were increased significantly by the combination of the double adjuvants Al(OH)_(3) and CpG.Our results showed that the virus-NAb lasted for more than six months in mice.To summarize,we have obtained a SARS-CoV-2 vaccine based on the RBD of the S glycoprotein expressed in glycoengineered Pichia pastoris,which stimulates neutralizing and protective antibody responses.A technical route for fucose-free complex-type N-glycosylation modified recombinant subunit vaccine preparation has been established.
文摘The aim of the paper was to determine benz(a)-pyrene in the preparations containing humates and study the benz(a)pyrene biological potency for the agricultural plants. The research methodology included the determination of the dependencies in the system “substance concentration (dose)—effect on the plant”. Concentrations of benz(a)pyrene in 12 samples of the humates preparations and fertilizers based on their trademarks “Irkutsk humates”, obtained from brown coal, varied in the range from 0.3 to 50 mcg/kg, which creates no soil contamination in conditions of the use of preparations. Between contents of benz(a)pyrene and humates there is a correlation (rxy = 0.95;α = 0.05). It is ascertained that the effects of stimulation and/or inhibition of the growth and yield of agricultural plants depend on the concentration of benz(a)pyrene and the method of plant processing. Optimal concentrations of benz(a)pyrene were 150-200 ng/dm3 for preplant way of processing of potato tubers, 3-10 ng/dm3—for top dressing (spraying) and 0.1-0.3 ng/dm3—for dressing under the roots (hydroponic). The obtained results allowed us to offer one of the possible mechanisms of biological potency of humates as the plant growth stimulants, and also a way testing of the preparations by screening of their benz(a)pyrene content.
基金the China National"863"Program(Approval No.2011AA10A212)Special Fund for Agro-Scientific Research in the Public Interest(ApprovalNo.201203056)
文摘Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed methods".Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.
文摘Light-emitting diodes (LEDs) can be used as an energy efficient alternative to high-pressure sodium (HPS), which have historically been the standard for supplemental lighting in cannabis cultivation. However, there is a lack of scientific understanding in the cannabis industry regarding plant physiology, which has resulted in the adoption of cannabis cultivation methods based on hearsay rather than scientific research. The goals of this study were to 1) compare LED lighting options that are commonly used in the cannabis industry and 2) compare the top performing LED light with an industry standard HPS light. Specifically, three LED lights were compared (California Light Works ((SolarSystem 1100), BIOS Lighting (Icarus Gi2), and Fluence Bioengineering (now Fluence by Osram) (SPYDR xPLUS)), based on light distribution, leaf temperature, and photosynthetic performance indices. The LED versus HPS comparison was based on light response curves measured at photosynthetic photon flux densities (PPFD) of (0, 100, 200, 300, 400, 500, 750, 1000, 1250, 1500, 1750 and 2000 μmol<span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>m<sup><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:nowrap;">∙</span>s<sup><span style="white-space:nowrap;">−</span>1</sup>), carbon assimilation rates (<em>A</em>) μmol CO<sub>2</sub> m<sup><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>s<sup><span style="white-space:nowrap;">−</span>1</sup> using a LiCor-6800 and resulting cannabinoid potency (THCA). The SPYDR xPLUS-Fluence by Osram had the highest performing LED light used in the LED comparison. At the suggested distance from bulb to canopy in the HPS versus LED comparison (6 inches for LEDs and 4 ft for HPS), carbon assimilation rates displayed a 142% percent increase in plants grown under LED vs. HPS with average photon flux densities of 795 and 298 μmol<span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>m<sup><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span>s<sup><span style="white-space:nowrap;">−</span>1</sup> for LED and HPS, respectively. All cultivars of<em> Cannabis sativa </em>L. showed increased cannabinoid potency when grown under LED illumination. The results of this study provide further insight regarding the selection of supplemental light to achieve maximum productivity of <em>Cannabis sativa</em> L.
文摘Surface plasmon resonance(SPR) systems are widely used for detailed characterization of antibody activities including antigen and Fc-receptor binding. During the later stages of development, where the focus is to ensure that established critical quality attributes(CQAs) are maintained during cell culture,purification and formulation processes, analysis is simplified, and relative potencies are often determined. Here, simulation of binding data revealed that relative potency values, determined via parallel line analysis(PLA) and half maximal effective concentration(EC50) analysis accurately reflect changes in active concentration only if binding kinetics remain unchanged. Changes in the association rate constant shifted dose response curves, and therefore relative potencies, in the same way as changes in analyte concentration do. However, for interactions characterized by stable binding, changes in the dissociation rate constant did not result in any shift, suggesting that this type of change may go unnoticed in the dose response curve. Thus, EC50 and PLA analyses of dose response curves obtained with an anti-TNF-α antibody were complemented with the Biacore functionality for sensorgram comparison analysis, whereby changes in antigen and Fc-receptor binding profiles could be detected. Next, analysis of temperature stressed TNF-α antibody revealed that calibration free concentration analysis(CFCA) data correlated perfectly with relative potency values. Together, these results demonstrate that combinations of SPR based dose response curves, sensorgram comparison and CFCA can be used to strengthen the confidence in relative potency assessments, and suggest that SPR can potentially be used as a surrogate potency assay in the quality control of biotherapeutic medicines.
文摘Cardiovascular complications of patients with type 2 diabetes mellitus(T2DM)threaten the health and life of numerous individuals.Recently,growth factor receptor-binding protein 10(GRB10)was found to play a pivotal role in vascular complications of T2DM,which participates in the regulation of lipid metabolism of T2DM patients.The genetic variation of GRB10 rs1800504 is closely related to the risk of coronary heart disease in patients with T2DM.The development of GRB10 as a key mediator in the association of lipid metabolism with cardiovascular complications in T2DM is detailed in and may provide new potential concerns for the study of cardiovascular complications in T2DM patients.
文摘Gastric parietal cells are important in acid secretion, but it is unclear which cells throughout the gastric gland have the highest secretion potency. Here, we used immunohistochemical methods with anti-H+, K+-ATPase, phosphoryl ezrin and CD44 antibodies to study the distribution of gastric acid secretion activity. Stomach tissues from freely fed and starved rats were cryofixed for light microscopy or fixed by high-pressure freezing for electron microscopy. Parietal cells from freely fed animals corresponded to the active secretion phase and to the inactive resting phase from starved rats. Anti-H+, K+-ATPase and anti-phosphoryl ezrin labeling were observed on the membrane of the intracellular canaliculi and the tubulovesicle from freely fed rats, while cells from starved animals showed weak labeling with anti-phosphoryl ezrin antibody staining. Morphometrical analysis at the electron microscopic level was performed on active and inactive acid secretory phases between the upper and base regions of the gland. H+, K+-ATPase and CD44 were distributed on both sites of the microvillous and tubulovesicle membrane in the same cells, but phosphoryl ezrin localized predominantly on the microvillous membrane in active cells of the glandular neck and upper base. Therefore, the highest secreting potency appeared to be in cells of the glandular neck and upper base.
文摘The treatment of type 1 diabetes is mainly dependent on insulin therapy and current formulated insulin formulations are used for its control all over the world. The presented study was designed to evaluate the potency of extracted, purified and formulated insulin from the pancreatic organs of the Sudanese beef cattle. Twenty healthy rabbits were used to conduct the study following subcutaneous administration of the sample insulin, to determine the hypoglycemic effect and to analyze the potency of the testing insulin by the hypoglycemic seizure method, blood sugar method and glucose enzymatic colorimetric test (GOD-PAP) respectively. The potency of the injected insulin samples was estimated by comparing the variation in blood glucose levels produced in the treated animals with that produced by a standard insulin preparation under the suitable conditions of the blood sugar method. The results revealed that the potency of the testing beef insulin samples was slightly higher (i.e., 2.2 USP units/ml, 9%) compared to the standard and assumed potency of the prepared insulin preparations (i.e., 1-2 USP units/ml) which indicated that the solvents and diluents used to prepare the assay dilution might be of higher potency and must be diluted to such an extent that the testing insulin potency must be compatible with the standard dilutions. Furthermore, to determine the choice of an assay to analyze the potency of insulin preparations, not only the accuracy of the result but also the purpose for which the test is to be used and the time limit must be taken into consideration.
文摘AIM:To describe confidence interval calculation for antidotal potency ratios using bootstrap method.METHODS:We can easily adapt the nonparametric bootstrap method which was invented by Efron to construct confidence intervals in such situations like this.The bootstrap method is a resampling method in which the bootstrap samples are obtained by resampling from the original sample.RESULTS:The described confidence interval calculation using bootstrap method does not require the sampling distribution antidotal potency ratio.This can serve as a substantial help for toxicologists,who are directed to employ the Dixon up-and-down method with the application of lower number of animals to determine lethal dose 50 values for characterizing the investigated toxic molecules and eventually for characterizing the antidotal protections by the test antidotal systems.CONCLUSION:The described method can serve as a useful tool in various other applications.Simplicity ofthe method makes it easier to do the calculation using most of the programming software packages.
基金supported by the Ministry of Science and Technology (project No.2007AA02Z417)
文摘Objective Both the 2, 6 linkage and its topology on target cells are critical for the recognition by human influenza virus. The binding preference of avian flu virus H5N1 HA to the 2, 3-1inked sialylated glycans is considered the major factor limiting its efficient infection and transmission in humans. To monitor potential adaptation of H5N1 virus in human population, the surveillance of receptor-binding specificity was undertaken in China. Methods The binding specificity of 32 human H5N1 virus strains isolated from 2003 to 2009 was tested by 2, 3-specific sialidase-treated chicken red blood cell （CRBC） agglutination assay and a solid-phase direct binding assay with synthetic sialylglycopolymers. Results Dual binding preference to 2, 3 and 2, 6-glycans were found in two strains： A/Guangdong/1/06 （A/GD/1/06） and A/Guangxi/1/08 （A/GX/1/08）. Though minor effect of short-2, 6-binding was detected in A/GX/1/08 at a low virus titer, both showed high affinity to the oligosaccharide at a high load. Notably both are of the long-2, 6-recognition, with the same topology as that of human H1N1 and H3N2 viruses. Conclusion The findings suggest that human H5N1 virus in China likely acquired the potential human-adaptation ability. Further research and surveillance on receptor-binding specificity of H5N1 viruses are required.
基金Supported by National Natural Science Foundation of China(31360544)
文摘Effects of different enucleation methods on developmental potency of pig handmade clone（HMC）reconstructed embryo was investigated in the paper.We compared enucleation efficiency of blind cut method,first polar body（Pb1）positioning method and demecolcine（DM）assisted enucleation,as well as their effects on development of HMC reconstructed embryos.The results showed that overall enucleation efficiency of Pb1 positioning method was significantly higher than that of blind cut method（P〈0.05）.The protuberance rate and overall enucleation efficiency of 0.4μg/mL DM treated group for 60 min was significantly higher than that of other concentrations and time treatment groups（P〈0.05）.For effects on development of HMC reconstructed embryos,there was no significant difference between DM-assisted enucleation and Pb1 positioning method.In conclusion,appropriate addition of DM could enhance enucleation efficiency of HMC,which had no significant influence on developmental potency of reconstructed embryos.
文摘Developmental potency of primitive and embryonic ectoderm cells from 4.50-day to 6.25-day post-coitum (p.c.) mouse embryos and primordial germ cells from 12.50-day p.c.male genital ridges of fetal mice were studied by direct introducing them into 3.50-day p.c.blastocysts.Sixteen (61.5) overt chimaeras out of 26(50%) offsprings were obtained after transfer of 52 blastocysts injected with 4.50-day primitive ectoderm cells;four (16.0%) overt chimaeras were obtained out of 25 (51.0%) offsprings with 4.75-day primitive ectoderm cells from 49 transferred blastocysts.However,no overt chimaera was obtained with either 5.25-day or 6.25-day embryonic ectoderm cells or 12.50-day male primordial germ cells.GPI analysis of mid-gestation conceptuses developed from injected blastocysts showedthat 5.25-day embryonic ectoderm cells could only contributed to yolk sac of conceptus.Results suggested that implantation acts as a trigger for the determination of primitive ectoderm cells,and their developmental potency becomes limited within a short period of time in normal development.
文摘The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evaluation. Mice were divided into groups for being immunized with corresponding serially diluted experimental SARS virus inactivated vaccine. And the rabbits were immunized with undiluted vaccine. Challenge assay was conducted with a heterologous SARS virus. And the neutralization antibody was determined with plaque reduction neutralization test (PRNT), to which the neutralization antibody in the convalescent serum of SARS patients was compared. The experimental vaccine viral strains were proved to be suitable for manufacturing the vaccine. Mice immunized by vaccines of serial dilutions were able to elicit neutralizing antibody. The antibody titer from mice immunized with the undiluted vaccine could reach up to 1∶495.2, while those of rabbits immunized with the undiluted vaccine could reach a GMT of 55.0-79.9. The capability of the antibody to neutralize the virus from Guangdong is more efficient than that from Beijing. The GMT of neutralizing antibody in SARS convalescents living in south and north China ranged from 50.12 to 54.95, and the titers of convalescents from north China were higher than those from south China. Mice and rabbits used as the model for evaluation of potency are of sensitivity, and the test is of reproducibility. The candidate challenge viral strains showed a relatively consistent effect on evaluating antibodies produced by various batches and different vaccine-source strains, hence they can be used to evaluate potency of the vaccine. The method for testing the vaccine potency and the evaluation standard was established preliminarily.
