Correlation of gut microorganisms and non-volatile flavor substances provides new insights for breeding Scylla paramamosain

The farming of Scylla paramamosain with specific flavors has a higher commercial value,and the flavors are related to the integrated farming environment and non-volatile flavor substances,while the survival environment is one of the important ways to source gut microorganisms in the organism.In this study,the levels of dominant taxa in the gut flora of S.paramamosain from Mong Cai,Vietnam(VN),Taishan City,Guangdong Province(TS)of China,and Ninghai County,Ningbo City(NB)Zhejiang Province of China converged with those of S.paramamosain from Sanmen County,Ningbo City(CK 1,CK 2,and CK 3)at 28 d of domestication.The top 15 genera with the highest abundance of VN,TS,and NB gut flora were the same as CK 1,CK 2,and CK 3,but with different percentages,and gradually converged to CK 1,CK 2,and CK 3,respectively,at 28 d of domestication.Correlation between intestinal flora and non-volatile flavor substances in the hepatopancreas at the percentage level of relative abundance of bacterial genera found that above 28 d of domestication,Muribaculaceae,Psychrilyobacter,Clostridia_vadinBB 60_group,Halarcobacter Carboxylicivirga,Sediminispirochaeta may be the most important genera affecting flavor amino acids of VN.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Psychrilyobacter,and Pseudomonas may be the most important genera affecting flavor amino acids of NB.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Vibrio,and Sphingomonas may be the most important genera affecting flavor amino acids of TS.These results show that the intestinal flora structure of crabs from different areas were domesticated in the same area for at least 28 d before they converged to that of the domesticated crab,and the most important genera affecting the flavor amino acids of TS,VN,and NB were also identified.The results of this study provide a reference and basis for the technique of directional cultivation of the flavor quality of the crab.

Occurrence,Spatial Distribution,Sources and Risk Assessment of Per-and Polyfluoroalkyl Substances in Surface Sediments of the Yellow River Delta Wetland

Per-and polyfluoroalkyl substances(PFASs)are emerging persistent organic pollutants(POPs).In this study,47 surface sediment samples were collected from the Yellow River Delta wetland(YRDW)to investigate the occurrence,spatial distribution,potential sources,and ecological risks of PFASs.Twenty-three out of 26 targeted PFASs were detected in surface sediment samples from the YRDW,with totalΣ23PFASs concentrations ranging from 0.23 to 16.30 ng g^(-1) dw and a median value of 2.27 ng g^(-1) dw.Perfluorooctanoic acid(PFOA),perfluorobutanoic acid(PFBA)and perfluorooctanesulfonic acid(PFOS)were the main contaminants.The detection frequency and concentration of perfluoroalkyl carboxylic acids(PFCAs)were higher than those of perfluoroal-kanesulfonic acids(PFSAs),while those of long-chain PFASs were higher than those of short-chain PFASs.The emerging PFASs substitutes were dominated by 6:2 chlorinated polyfluoroalkyl ether sulfonic acid(6:2 Cl-PFESA).The distribution of PFASs is significantly influenced by the total organic carbon content in the sediments.The concentration of PFASs seems to be related to human activities,with high concentration levels of PFASs near locations such as beaches and villages.By using a positive matrix factorization model,the potential sources of PFASs in the region were identified as metal plating mist inhibitor and fluoropolymer manufacturing sources,metal plating industry and firefighting foam and textile treatment sources,and food packaging material sources.The risk assessment indicated that PFASs in YRDW sediments do not pose a significant ecological risk to benthic organisms in the region overall,but PFOA and PFOS exert a low to moderate risk at individual stations.

Research Progress of Volatile Substances Analysis and Sensory Evaluation of Soymilk

Soybean is one of the important crops in China. Soymilk, a traditional neutral plant-based protein drink, is rich in high quality proteins. Although soybean milk is rich in nutrients, its marketing among consumers, especially those in Western countries who are used to peaceful flavor, has been limited due to the adverse flavor impact brought by its special composition. In recent years, with the increasing attention to the nutritional value of soymilk, the flavor of soymilk has become a popular research object for scholars at home and abroad. The flavor components of soymilk are mainly volatile small molecular compounds produced by enzymatic reactions catalyzed by lipoxygenase(LOX). After formation, they interact with protein macromolecules to form the overall flavor of soymilk. At present, there are many methods to control the off-odor of soymilk at home and abroad, including physical heating methods, chemical methods, biological enzymatic digestion methods, mask methods, and a variety of breeding methods. These methods effectively reduce the off-odor of soymilk, but all of them have shortcomings. Currently, the sensory characteristics of the beany odor in soymilk are evaluated mainly by traditional human sensory scoring along with the assistance of modern instrument analysis of volatile flavor substances using headspace solid phase microextraction(SPME) gas chromatography coupled with-mass spectrometry(GC-MS). This paper summarized the research results of volatile flavor substances in soymilk in recent years and the sensory evaluation methods of soymilk at home and abroad, and looked forward to the future development direction, hoping to provide some theoretical bases and reference detection methods for solving the problem of soymilk flavor in the future.

Could school programs based on social-emotional learning prevent substance abuse among adolescents?

In this editorial,we comment on the article Adolescent suicide risk factors and the integration of social-emotional skills in school-based prevention programs by Liu et al.While the article focused on the issue of suicide and social-emotional learning programs as a possible intervention,we here discuss evidence of other reported outcomes and if it could be an effective way to prevent substance abuse among adolescents.

Evaluation of Rhizobium tropici-Derived Extracellular Polymeric Substances on Selected Soil Properties, Seed Germination, and Growth of Black-Eyed Peas (Vigna unguiculata)

Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.

Contemporary strategies and approaches for characterizing composition and enhancing biofilm penetration targeting bacterial extracellular polymeric substances

Extracellular polymeric substances(EPS)constitutes crucial elements within bacterial biofilms,facili-tating accelerated antimicrobial resistance and conferring defense against the host's immune cells.Developing precise and effective antibiofilm approaches and strategies,tailored to the specific charac-teristics of EPS composition,can offer valuable insights for the creation of novel antimicrobial drugs.This,in turn,holds the potential to mitigate the alarming issue of bacterial drug resistance.Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias,which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds.Considering the pivotal role of EPS in biofilm functionality,it is imperative for EPS research to delve deeper into the analysis of intricate compositions,moving beyond the current focus on polymeric materials.This ne-cessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches.In this study,we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions.Additionally,novel strategies aimed at targeting EPS to enhance biofilm penetration were explored,with a specific focus on high-lighting the limitations associated with colorimetric methods.Furthermore,we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges.This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS,thereby inhibiting biofilm formation.This insight opens up a new avenue for exploration within this research domain.

Preserving the Ozone Layers: Battling Illegal Trade in Ozone-Depleting Substances

The depletion of the ozone layer, a vital shield protecting the Earth from harmful ultraviolet (UV) radiation, is now a worldwide environmental concern. Human activities, particularly the release of ozone depleting substances (ODS), have led to the thinning of this protective layer over recent decades. Simultaneously, illegal trade has emerged as a global challenge, giving rise to economic issues, losses of tax revenue, heightened criminal activities, health risks, and environmental hazards. The depletion of the ozone layer, a critical shield protecting the Earth from harmful ultraviolet (UV) radiation, has become a global environmental concern. This paper delves into the legal dimensions surrounding ozone-depleting substances (ODS), their impact on the ozone layer, and the subsequent risk of skin cancer. As countries navigate international agreements, domestic regulations, and enforcement mechanisms, the intricate interplay between legal frameworks and the health implications of ozone layer depletion comes to the forefront. The paper highlights particular instances of illegal trade in ozone depleting substances, drawing from data reported by the parties to the Montreal Protocol. Notably, China stands out as a significant source of contraband ODS, with other countries such as Bulgaria, Lithuania, Poland, and France reporting numerous cases. Analyzing these case instances offers insights into the efficacy of legal frameworks and enforcement measures. The paper offers a comprehensive set of recommendations to strengthen global control and enforcement against the illegal trade of ozone depleting substances. These recommendations span diverse aspects such as production monitoring, customs collaboration, mutual verification, cross-border agreements, public-private partnerships, international cooperation, detection equipment, global regulatory standards, resource allocation, public awareness campaigns, alternative substance development, and controlling the trade at its source. By applying these recommendations and enhancing enforcement measures, we aim to protect the ozone layer and create a healthier and safer world for future generations and achieve sustainable development goals.

The Role of Jasmonates as Antibulbing Substances in the Bulb Formation of Onion

Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation.

Analyzing the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells

Background:Xuefu Zhuyu decoction(XFZY)could significantly improve the function of hypertensive vascular endothelial cells,but the targets and mechanism are not clear.This study is to analyze the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells.Methods:This study used Xuefu Zhuyu decoction to intervene human umbilical vein endothelial cells incubated by hypertensive patients’serum,then detected the function of vascular endothelial cells.The aqueous extract of XFZY was analyzed and validated by liquid chromatography-mass spectrometry technology;Finally,macromolecular docking technology was used to analyze the potential active substances and targets of XFZY in the prevention and treatment of hypertension.Results:Compared with the model group,the XFZY group showed a significant increase in NO expression(P<0.01)and a significant decrease in ET-1 expression(P<0.001);and the expression of BIP,P-JNK,CHOP,and BAX in XFZY group cells was significantly decreased(P<0.001),while the expression of JNK and BCL2 was significantly increased(P<0.001).19 main compounds were identified in XFZY and there were 3 pairs of molecular complexes with high affinity for markers of the endoplasmic reticulum stress,including BIP-Hesperidin complex,BIP-HSYA complex and JNK-Naringin complex.Conclusion:This study analyzed the potential pharmacodynamic substance and targets of Xuefu Zhuyu decoction in improving the function of hypertensive vascular endothelial cells,which could provide a scientific basis for the future molecular mechanism of XFZY in treating hypertension.

Advances in Research Methods of Pharmacodynamic Substances in Traditional Chinese Medicines and Their Application in the Teaching of Traditional Chinese Medicine Analysi

With the continuous progress of science and technology,the research methods of pharmacodynamic substances in traditional Chinese medicine are developing,and the application of these methods in teaching is becoming more and more extensive.By introducing these research methods into the classroom,teachers can help students to deeply understand the nature and mechanism of action of pharmacodynamic substances in traditional Chinese medicine,and improve their interest in and knowledge of traditional Chinese medicine.This paper introduces the definition of pharmacodynamic substances in traditional Chinese medicine,research methods,and their application in the teaching of traditional Chinese medicine analysis.

Relationship and effect of redox potential,jarosites and extracellular polymeric substances in bioleaching chalcopyrite by acidithiobacillus ferrooxidans

The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2＋ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different conditions of initial total-iron amount as well as mole ratio of Fe（III） to Fe（II） in the solutions containing synthetic extracellular polymeric substances （EPS）.When the solution potential is lower than 650 mV （vs SHE）,the inhibition of jarosites to bioleaching chalcopyrite is not vital as EPS produced by bacteria can retard the contamination through flocculating jarosites even if concentration of Fe（III） ions is up to 20 g/L but increases with increasing the concentration of Fe（III） ions;jarosites formed by bio-oxidized Fe3＋ ions are more easy to adhere to outside surface of EPS space on chalcopyrite;the EPS layer with jarosites acts as a weak diffusion barrier to further rapidly create a high redox potential of more than 650 mV by bio-oxidizing Fe^2＋ ions inside and outside EPS space into Fe^3＋ ions,resulting in a rapid deterioration of ion diffusion performance of the EPS layer to inhibit bioleaching chalcopyrite severely and irreversibly.

Interaction mechanism of Cu^(2+),Fe^(3+) ions and extracellular polymeric substances during bioleaching chalcopyrite by Acidithiobacillus ferrooxidans ATCC2370

The extracellular polymeric substances（EPS） of Acidithiobacillus ferrooxidans ATCC 23270,and iron and copper enclosed in EPS were extracted by ultrasonication and centrifugation methods to determine the interaction mechanism of Cu2＋,Fe3＋ and EPS during bioleaching chalcopyrite.Generally,Cu2＋ ions can stimulate bacteria to produce more EPS than Fe3＋ ions.The mass ratio of Fe3＋/Cu2＋ enclosed in EPS decreased gradually from about 4：1 to about 2：1 when the concentration of Cu2＋ ions increased from 0.01 to 0.04 mol/L.The amount of iron and copper bound together by EPS in ferrous-free 9K medium containing 1% chalcopyrite was about 2 times of that in 9K medium containing 0.04 mol/L Cu2＋ ions.It was inferred that the EPS with jarosites on the surface of chalcopyrite gradually acted as a weak diffusion barrier for Cu2＋,Fe3＋ ions transference during bioleaching chalcopyrite.

Study on the Effect of Osmosis-regulating Substances and Organic Appendices on Somatic Embryogenesis in Wheat

[Objective] The study aimed to reveal the effect of osmosis-regulating substances and organic appendices on somatic embryogenesis in wheat. [Method] The suitable concentration combination of appendices was optimized by adding different concentrations of osmosis-regulating substances including mannitol, sorbitol and organic appendices such as Gln, CH and LH, into the somatic embryogenesis in wheat. [Result] The mannitol or sorbitol lower than 40 g/L was helpful for improving somatic embryogenesis; there was no significant difference in the induction rate of somatic embryogenesis when 300-500 mg/L Gln、CH or LH was respectively added into the induced medium, while somatic embryogenesis could be enhanced dramatically in the presence of 500 mg/L Gln together with 300 mg/L CH. [Conclusion] Somatic embryogenesis could be improved to some extent by different concentrations of osmosis-regulating substances and organic appendices, which laid foundation for establishing a more perfect system of somatic embryogenesis in wheat.

Study on Purification and Properties of Antibacterial Substance from Antagonistic Bacteria P72 against Wheat Scab

[Objective] The study aimed to explore the antibacterial activity and stability of antagonistic bacteria P72 against wheat scab.[Method] The Bacillus subtilis P72 was inoculated into fermentation media with the inoculation amount 5%,then cultured on shaking table at 28 ℃ for 48 h and centrifuged at 8 000 r/min for 10 min.The supernatant of fermentation broth was purified and then the genetic stability,thermal stability and pH stability were detected.[Result] By DEAE-52 ion exchange chromatography,the protein eluted by 0.5 mol/L NaCl solution possessed the strongest antagonistic ability against wheat scab pathogen.The SDS-PAGE electrophoresis showed that the molecular weight of the purified protein with antibacterial effect was 40 kD.By stability test,the antibacterial substance produced by P72 strain showed heritable antagonistic activity,high stability below 60 ℃,stability to acid and unstability to alkali.[Conclusion] The antagonistic bacteria P72 had strong antagonistic ability to wheat scab pathogen,stable antibacterial activity and thermal stability,so it would possess a wide development prospect.

Effects of Drought Stress on Osmotic Regulation Substances of Five Catalpa bungei Clones

[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to differentiate the degrees of drought stress based on changes in soil water content and leaf water potential and investigate variations in contents of osmotic regulation substances（free proline,soluble sugar and soluble protein） in leaves of five Catalpa bungei clones under different degrees of drought stresses. [Result] According to changes in soil water content and leaf water potential, the whole process of drought stress was divided into normal level（CK, with soil water content of 97.49% and leaf water potential of-0.54MPa）, light drought（LD with soil water content of 59.96% and leaf water potential of-1.28 MPa）, mediate drought（MD with soil water content of 34.19% and leaf water potential of-2.32 MPa） and severe drought（SD with soil water content of 14.52%and leaf water potential of-2.99 MPa）. The soil water content and leaf water potential of five Catalpa bungei clones reached the highest correlation in exponential fitting, with an average R2of 0.989 3（P0.001）. The free proline content in leaves of five Catalpa bungei clones increased rapidly with the increasing degree of drought stress（P 0.001）. To be specific, free proline contents of Catalpa bungei clones015-1 and 7080 were 34.39 and 33.41 times of the normal level under severe drought conditions, which reached an extremely significant level（P0.001）; the free proline content of Catalpa bungei clone 1-3 rapidly increased to（855.46±227.52） μg/g Fw under light drought conditions. The soluble protein content in leaves showed different variation trends. To be specific, the soluble protein content of Catalpa bungei clone 7080 was the lowest at various drought stages and reached（1.644 ±0.137）mg/g Fw under normal conditions; the soluble protein content of Catalpa bungei clone 1-3 was relatively high under normal conditions and was reduced rapidly under light drought conditions, showing different response patterns. [Conclusion] Osmotic regulation substances in leaves of five Catalpa bungei clones all have certain response to drought stress. Free proline is the most important osmotic regulation substance, followed by soluble protein, while soluble sugar makes no significant contribution. According to changes in content of osmotic regulation substances, Catalpa bungei clone 7080 has relatively high capacity and good drought resistance, while Catalpa bungei clone 1-3 has the rapidest response to drought stress.

Effects of Balanced Fertilization on Mulberry Leaf Quality and Its Active Substance Content

This paper study the effect of nitrogen （N, X1）, phosphorus （P, X2） and potassium （K, X3） in different amounts on crude protein, soluble sugar, total flavonoid and 1-deoxynojirimycin contents in mulberry leaves, with mulberry trees in spring and autumn as the material and as per ＂3414＂ experimental design. The results showed that the qualities and active substance content of mulberry leaves changed from increasing to decreasing with its development; crude protein and solu-ble sugar achieved the peak on August 20; total flavonoid and 1-deoxynojirimycin was the highest on May 15. Fertilizations with N, P and K fertilizers at different amounts had significant effects on quality of mulberry leaf and content of active substances. Specifically, as fertilizer amount increased, the content of active sub- stances grew dramatically and achieved the highest at level 2 （X^2X=X~_）. Based on fertilizer effect functions of objective yield, the recommended amounts of N, P and K fertilizers based on crude protein, soluble sugar, flavonoid content and DNJ in test sites were 718.46, 220.11 and 305.23 kg/hm2, when the highest of crude protein in mulberry leaf was 1 813.83 kg/hm2. When N, P and K fertilizers were recommended at 666.54, 204.41 and 243.18 kg/hm2, soluble sugar in mulberry leaf achieved the peak at 1 042.65 kg/hm2. When N, P and K fertilizers were at 675.96, 326.49 and 462.90 kg/hm2, flavonoid content achieved the maximum at 147.90 kg/hm2. When N, P and K fertilizers were at 720.9, 225.11 and 323.63 kg/hm2, DNJ content was the highest at 13.55 kg/hm2.

Development and Validation of Liquid Chromatographic Method for the Determination of the Related Substances of Rifampicin

A number of HPLC methods have been approved for the determination of rifampicin, but no references involved the assay of related substances of rifampicin. In the present paper, a reversed-phase liquid chromatographic method for the determination of related substances of rifampicin is developed and validated. Rifampicin and its related substances, including rifamycin SV, rifampicin N-oxide and 3-formylrifamycin SV were separated using a Zorbax Eclipse C8, 250×4.6 mm(i.d), 5 μm column by isocratic elution at a flow rate of 1 mL·min -1. The detector was set at 254 nm. The mobile phase is a mixture of methanol-acetonitrile -0.075 mol·L -1 monopotassium phosphate -1.0 mol·L -1 citric acid (31:31:35:3, v/v). The method validation included accuracy, precision, linearity, sensitivity and stability. All results are shown to be acceptable.

Effect of Different Flue-curing Techniques on the Taste and Aroma Substances of Tobacco Leaves

[Objective]This study aimed to optimize the conditions for curing tobacco leaf, so as to improve its flavor and quality. [Method] Leaves of Yuanyan 87 were col ected and cured by three different techniques （moderate-intensity conditions throughout the curing course; high-intensity conditions at leaf yel owing and wilting stages, moderate-intensity conditions at leaf drying and vein drying stages; high-in-tensity conditions throughout the curing course）, and then the contents of 48 aroma substances and taste indices of the finished tobacco leaves were measured. [Result] The contents of 28 aroma substances in the tobacco leaves cured under high-inten-sity conditions throughout the course were higher and the taste indices of these to-bacco leaves were better, compared with those flue-cured by the other two tech-niques. The contents of the other 20 aroma substances were not significantly af-fected by the curing techniques. The second best technique was high-intensity con-ditions at leaf yel owing and wilting stages and moderate-intensity conditions at leaf drying and vein drying stages. Curing tobacco leaves at moderate-intensity condi-tions throughout the course was the worst one. [Conclusion] Compared with the oth-er two methods, the contents of aroma substances and taste indices of the tobacco leaves cured under high-intensive conditions throughout the course were the best.

神经肽类似物DOTA-Substance P的^(177)Lu标记及其生物分布

为探讨神经肽类药物177 Lu-DOTA-Substance P(以下简称为177 Lu-DOTA-SP)用于人胰腺癌PANC-1的肿瘤显像及治疗的可能性,研究了DOTA-SP的177 Lu标记;考察了177 Lu-DOTA-SP在室温下生理盐水中与在37℃小牛血清中的稳定性;评价了177 Lu-DOTA-SP在正常昆明小鼠与人胰腺癌PANC-1模型裸鼠体内的生物分布特点,并对人胰腺癌PANC-1模型裸鼠进行了SPECT显像研究。结果表明,在优化条件下,DOTA-SP的177 Lu标记率>90%,纯化后,177 Lu-DOTA-SP的放化纯度>98%。177 Lu-DOTA-SP在生理盐水与5%小牛血清中显示了良好的稳定性,与浓度较高的血清(10%)竞争反应时,其降解稍快。177 Lu-DOTA-SP在正常昆明小白鼠体内的生物分布特点为:血清除快,肾放射性摄取高且滞留时间长;骨中有一定放射性摄取,且滞留长。177 Lu-DOTA-SP在人胰腺癌PANC-1模型裸鼠中的体内分布结果表明,肿瘤细胞中放射性摄取在给药后不同时间点均高于正常胰腺细胞中的放射性摄取,提示在PANC-1肿瘤细胞中有NK-1受体存在。SPECT显像结果显示,177 Lu-DOTA-SP在肿瘤细胞中放射性浓集并不明显。177 Lu-DOTA-SP应用于胰腺癌肿瘤显像与治疗的价值尚需进一步研究。

Preliminary Study on Algae-lysing Active Substances of Algae-lysing Bacteria

Algae-lysing bacteria A1 has good control effect on the moss through its extracellular secretion. In order to further study its control mechanism, the sin- gle-factor tests of temperature and pH value, the activated carbon adsorption test, the organic solvent extraction test and the crude extract of active substance test were carried out to explore the characteristics of active substances. The results showed that the algae-lysing active ingredient of A1 strain had strong thermal stabili- ty, which still had good algae-lysing effect after being treated at 121 ℃ ; when the pH values of fermentation liquid were adjusted to 2.0 and 4.0 respectively, the active substances lost their activities, but their control ability against moss would be enhanced under the alkaline conditions ; the active substances could not be ad- sorbed by activated carbon; the algae-lysing active substances showed strong hydrophilie ability when they were extracted by ethyl acetate, petroleum ether and chloroform. Therefore, it could be speculated that the active substances belonged to carbohydrates. The crude extract results of algae-lysing active substances showed that the active substances secreted by A1 strain were composed by a variety of algae-lysing active substances.