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摘要： The BST oilfield in the northwestern Taklamakan Desert is a fractured carbonate reservoir,but issues of water breakthrough are becoming increasingly severe with the development of water flooding.Unfortunately,the high-temperature and high-salt conditions(130°C,71695 mg/L)of the BST oilfield pose challenges for the development of plugging agents.In this study,the effects of 2-acrylamido-2-methylpropane sulfonic acid(AMPS)content on AM/AMPS copolymers and gels were studied through viscosity measurements,nuclear magnetic resonance(NMR),and cryo-scanning electron microscope(Cryo-SEM).Moreover,the AMPS stabilization mechanism of the polymers and gels was explained.Heatresistant and salt-tolerant gel systems were developed,and their gelation properties,thermal stability,injection capacity,and plugging ability were evaluated.Experimental results showed inconsistencies between the effects of AMPS content on the polymers and gels.For the polymers,the thermal stability increased with increased AMPS content in the polymer.However,excessive AMPS content resulted in poor gelation and low strength.The developed gel systems with S30 polymer(AMPS content is approximately 26%)exhibited excellent thermal stability,controllable gelation time,good injection capacity,and plugging ability.The field application results indicated that most production wells had a positive response,with reduced water-cut and increased daily oil production.

摘要： ASTM A182 F51 duplex stainless steel with a 50:50 ratio of austenite to ferrite microstructure is a material used in mechanical engineering.Its uses include the manufacturing of equipment and components subject to acidification or acid stimulation for oil and gas industries.During acid stimulation or acidification,hydrochloric acid(HCl)solution with concentrations ranging from 5%to 28%(by volume)is injected into the limestone(CaCO3)and dolomite(CaCO3·MgCO3)reservoir rock to restore permeability and consequently increase oil well productivity.Therefore,it is important to use a corrosion inhibitor,such as propargyl alcohol,to prevent or inhibit the aggressive attack of HCl on duplex stainless steel.The present study evaluates the corrosion resistance of ASTM A182 F51 stainless steel using gravimetric(mass loss)and electrochemical(polarization)tests.Studies were completed with and without the addition of 500 and 1,000 mg/L propargyl alcohol in HCl solutions with concentrations of 10%and 15%(by volume)at temperatures of 25,40 and 55°C.The good protection by propargyl alcohol of duplex steel immersed in HCl is observed.

摘要： The objective of this research was to evaluate the impact of the VIUSID Vet(powder and solution)nutritional supplement on the productive performance of growing-finishing pigs.Two experiments were conducted,each using 210 pigs at an average age of 40 d—70 per treatment—which were distributed into 15 pens(five per group).The experiments lasted 170 d.The treatments consisted in:Experiment 1,Group I control group;Group II received from the start 1.5 g of VIUSID Vet powder per kilogram of feed daily for 90 d;Group III same as the former,but instead given 2.0 g.Experiment 2,Group I control;Group II received from the start 1.5 g of VIUSID Vet powder per kilogram of feed daily for 90 d;Group III same as the former,but instead given 1.5 mL of VIUSID Vet solution per kilogram of feed.VIUSID Vet(powder or solution)significantly improved weight gain and feed conversion as well as reduced deaths when given doses of 2.0 g and 1.5 g or 1.5 mL per kilogram of feed during the first 90 d of the growing-finishing phase,giving rise to financial benefits.

摘要： BACKGROUND Postoperative liver failure is the most severe complication in cirrhotic patients with hepatocellular carcinoma(HCC) after major hepatectomy. Current available clinical indexes predicting postoperative residual liver function are not sufficiently accurate.AIM To determine a radiomics model based on preoperative gadoxetic acid-enhanced magnetic resonance imaging for predicting liver failure in cirrhotic patients with HCC after major hepatectomy.METHODS For this retrospective study, a radiomics-based model was developed based on preoperative hepatobiliary phase gadoxetic acid-enhanced magnetic resonance images in 101 patients with HCC between June 2012 and June 2018. Sixty-one radiomic features were extracted from hepatobiliary phase images and selected by the least absolute shrinkage and selection operator method to construct a radiomics signature. A clinical prediction model, and radiomics-based model incorporating significant clinical indexes and radiomics signature were built using multivariable logistic regression analysis. The integrated radiomics-based model was presented as a radiomics nomogram. The performances of clinical prediction model, radiomics signature, and radiomics-based model for predicting post-operative liver failure were determined using receiver operating characteristics curve, calibration curve, and decision curve analyses.RESULTS Five radiomics features from hepatobiliary phase images were selected to construct the radiomics signature. The clinical prediction model, radiomics signature, and radiomics-based model incorporating indocyanine green clearance rate at 15 min and radiomics signature showed favorable performance for predicting postoperative liver failure(area under the curve: 0.809-0.894). The radiomics-based model achieved the highest performance for predicting liver failure(area under the curve: 0.894;95%CI: 0.823-0.964). The integrated discrimination improvement analysis showed a significant improvement in the accuracy of liver failure prediction when radiomics signature was added to the clinical prediction model(integrated discrimination improvement = 0.117, P =0.002). The calibration curve and an insignificant Hosmer-Lemeshow test statistic(P = 0.841) demonstrated good calibration of the radiomics-based model. The decision curve analysis showed that patients would benefit more from a radiomics-based prediction model than from a clinical prediction model and radiomics signature alone.CONCLUSION A radiomics-based model of preoperative gadoxetic acid–enhanced MRI can be used to predict liver failure in cirrhotic patients with HCC after major hepatectomy.

摘要： Salicylic acid(SA) is an important signaling substance that plays an important role in plant growth, development and disease resistance.Inorder to further understand the role of the SA pathway in potato disease resistance and identify SA signaling key genes, gene expression profiling of the late blight resistance genotype SD20 was performed under exogenous SA application. A total of 28 572 unigenes were assembled,of which 4 564 were differentially expressed. Analysis of differentially expressed genes(DEGs) showed that multiple signaling pathways such as SA, jasmonic acid, ethylene, abscisic acid, auxin, and brassinolide were involved in response to exogenous SA. Many plant defense signalrelated genes involved in protein serine/threonine kinase activity and plant-pathogen interaction, were significantly enriched. These were consistent with the interaction results of SD20 and Phytophthora infestans in our previous study, indicating that exogenous SA stimulated the resistance response and initiated a similar defense pathway compared to pathogen infection in SD20, which confirmed crosstalk of the SA signaling pathway with a pathogen-induced disease resistance signal pathway in plant. Moreover, transcriptome analysis revealed that ROS1 was positively regulated by SA in potato for the first time. SA-induced gene expression profiling provides insight into SA signaling and its mechanisms in disease defense systems.

摘要： BACKGROUND Escherichia coli(E.coli)express flagella to ascend human urinary tracts.To survive in the acidic pH of human urine,E.coli uses the glutamate decarboxylase acid response system,which is regulated by the GadE protein.AIM To determine if growth in an acidic pH environment affected fliC transcription and whether GadE regulated that transcription.METHODS A fliC-lacZ reporter fusion was created on a single copy number plasmid to assess the effects of acidic pH on fliC transcription.Further,aΔgadE mutant strain of a uropathogenic E.coli was created and tested for motility compared to the wildtype strain.RESULTS Escherichia coli cells carrying the fliC-lacZ fusion displayed significantly less fliC transcription when grown in an acidic pH medium compared to when grown in a neutral pH medium.Transcription of fliC fell further when the E.coli was grown in an acidic pH/high osmolarity environment.Since GadE is a critical regulator of one acid response system,fliC transcription was tested in a gadE mutant strain grown under acidic conditions.Expression of fliC was derepressed in the E.coli gadE mutant strain grown under acidic conditions compared to that in wild-type bacteria under the same conditions.Furthermore,a gadE mutation in a uropathogenic E.coli background exhibited significantly greater motility than the wild-type strain following growth in an acidic medium.CONCLUSION Together,our results suggest that GadE may down-regulate fliC transcription and motility in E.coli grown under acidic conditions.

摘要： Periodontitis is a type of chronic inflammation in the gingival tissue caused by infectious bacteria colonizing the surface of the teeth,leading to the destruction of tooth-supporting tissues and loss of alveolar bone.Suberoylanilide hydroxamic acid(SAHA),a class of histone deacetylase(HDAC)inhibitor,has the potential to stimulate osteoblast differentiation by acetylating histone proteins,and thus suppressing the expression of adipogenic and chondrogenic genes.However,the effect of SAHA on the differentiation of human periodontal ligament stem cells(hPDLSCs)is yet to be elucidated.Herein,we investigated the effects of SAHA on in vitro proliferation and differentiation of hPDLSCs by MTT assay,Alizarin Red-S,and alkaline phosphatase staining,and real-time PCR.Notably,300 ng/mL SAHA treatment enhanced the proliferation and mineralization of hPDLSCs,indicating their osteogenic potential.Moreover,a significant enhancement of osteogenesis gene markers and proteins was observed.We also demonstrated that ERK is a positive regulator of Runx2 transcription factors during osteoblast differentiation.These results indicate that SAHA may be a useful osteogenic induction agent for periodontal bone regeneration.

摘要： While phthalate acid esters(PAEs)cannot fluoresce alone,they can be detected by fluorescence spectroscopy after chelation with bovine serum albumin(BSA).In this study,the types of amino acid residues at the active site of PAEs chelated with BSA were determined using molecular docking technology.A modification scheme of BSA with higher detection sensitivity fluorescence spectroscopy for PAEs was proposed based on the docking results and constructed for a novel BSA structure with a higher detection sensitivity of fluorescence spectroscopy using a homologous modeling method.Density functional theory(DFT)was employed to explore the influence before and after BSA modification on PAEs’detection through fluorescence spectroscopy.The results showed that the docking scores between BSAs and dimethyl phthalate(DMP),dibutyl phthalate(DBP)and di-n-octyl phthalate(DNOP)were increased up to 26.45%,16.82%and 16.30%,respectively,indicating that the active site modification of BSA could enhance the binding affinity between BSA and PAEs.The fluorescence intensity of PAEs chelated with modified BSAs were calculated.The fluorescence intensity of fluorescence spectroscopy for DMP,DBP and DNOP chelated with BSAs after modification was increased up to 2.8-,104.51-and 62.43-fold,respectively,which achieved the purpose of theoretically modifying BSA to improve the detection sensitivity of fluorescence spectroscopy for PAEs.

摘要： The current study investigated the comparative oxidative damage in twomaize seedlings induced by saline,drought,and combined stress and the ameliorative role of two different doses(20 and 80μM)of 5-aminolevulinic acid(ALA)against the above-mentioned stresses.Hydroponically grown 10-day-old maize(Zea mays,var.BARI Hybrid Maize-7(BHM-7)and BARI Hybrid Maize-9(BHM-9))seedlings were exposed to 12 dS/m of saline solution,200 mM mannitol-induced drought stress alone and their combined stress for 7 days.Result revealed that individual stresses retard the plant growth to some degrees,however,their combined stress has more detrimental effects,which might be correlated with lipid peroxidation(MDA)-induced oxidative stress in seedlings,enhanced Na+/K+ratio,and augmented generation of superoxide(O_(2)•^(−))and hydrogen peroxide(H_(2)O_(2)).In contrast,exogenous ALA supplementation at 20μM concentration markedly recovered from chlorosis and growth inhibition,substantially scavenged reactive oxygen species(ROS)and MDA by preserving ionhomeostasis and relaxing oxidative stress,also,by boosting catalase(CAT)and glutathione S-transferase(GST),and exclusively via depressing the activity of lipoxygenase(LOX)antioxidant enzyme.On the contrary,80μM ALA made things worse,nevertheless,higher activities shown by other antioxidant enzymes,like,superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POD),and glutathione peroxidase(GPX),which were related to lessen the oxidative damage by highly produced O_(2)•^(−)and H_(2)O_(2) under combined stress.Non-denaturing gel electrophoresis was done for further confirmation.However,ALA importantly increased the photosynthetic pigment contents in both genotypes irrespective of doses.Nevertheless,GST might have assisted the plants to escape from the herbicidal effect by detoxification.However,in the combined stress condition,high ALA concentration may have some positive role to play.Our findings also showed that BHM-9 performed better than BHM-7.Therefore,ALA at lower concentration was effective for single stress of saline and drought,while higher concentration can improve plant survival under combined stress.

摘要： Clubroot of Chinese cabbage(Brassica rapa L.ssp.pekinensis),caused by the obligate parasite Plasmodiophora brassicae,accounts for serious yield losses.The aim of our study was to explore the phytohormone levels and metabolome changes in the roots of resistant and susceptible B.rapa genotypes at a late stage of infection,i.e.,28 days post-infection.Both genotypes showed decreased auxin levels after P.brassicae infection except for indole-3-acetic acid.Overall,the susceptible genotype had higher auxin and cytokinin levels after infection,with the exception of trans-zeatin and 3-indolebutyric acid as compared to the resistant genotype.Jasmonic acid levels declined after infection regardless of the genotype.Resistance against clubroot was evident with the increased levels of salicylic acid in the resistant genotype.The susceptible genotype had a higher number of differentially accumulated metabolites(DAMs)(262)than the resistant genotype(238)after infection.Interestingly,132 DAMs were commonly detected in both genotypes when infected with the pathogen,belonging to metabolite classes such as phenolic acids,amino acids,and derivatives,glucosinolates,organic acids,flavonoids,nucleotides and derivatives,and fatty acids.The differential metabolite analysis revealed that metabolites related to amino acid biosynthesis,fatty acid biosynthesis and elongation,glutathione metabolism,and glucosinolate metabolism were highly accumulated in the resistant genotype,suggesting their essential roles in resistance against P.brassicae infection.

摘要： 以紫外光(λ=254nm)为光源,研究了氰氟草酯及其活性代谢产物ACID在不同介质水溶液中的光化学降解.在紫外光下,氰氟草酯及ACID在pH5.0的缓冲溶液和去离子水中易发生光解,半衰期约4~6min,丙酮的存在对氰氟草酯及ACID的光解有延缓作用.通过GC-MS和标样法鉴定了氰氟草酯及ACID光解后的部分光解产物,从而推测了可能的光解途径.

摘要： 以紫外光(λ=254nm)为光源,研究了氰氟草酯及其活性代谢产物ACID在不同介质水溶液中的光化学降解.在紫外光下,氰氟草酯及ACID在pH5.0的缓冲溶液和去离子水中易发生光解,半衰期约4~6min,丙酮的存在对氰氟草酯及ACID的光解有延缓作用.通过GC-MS和标样法鉴定了氰氟草酯及ACID光解后的部分光解产物,从而推测了可能的光解途径.

摘要： 以紫外光(λ=254nm)为光源,研究了氰氟草酯及其活性代谢产物ACID在不同介质水溶液中的光化学降解.在紫外光下,氰氟草酯及ACID在pH5.0的缓冲溶液和去离子水中易发生光解,半衰期约4~6min,丙酮的存在对氰氟草酯及ACID的光解有延缓作用.通过GC-MS和标样法鉴定了氰氟草酯及ACID光解后的部分光解产物,从而推测了可能的光解途径.

摘要： 以紫外光(λ=254nm)为光源,研究了氰氟草酯及其活性代谢产物ACID在不同介质水溶液中的光化学降解.在紫外光下,氰氟草酯及ACID在pH5.0的缓冲溶液和去离子水中易发生光解,半衰期约4~6min,丙酮的存在对氰氟草酯及ACID的光解有延缓作用.通过GC-MS和标样法鉴定了氰氟草酯及ACID光解后的部分光解产物,从而推测了可能的光解途径.

摘要： 本发明涉及一种源于草酸青霉的黑麦酮酸类化合物Secalonic acid K及制备方法。该化合物具有抑制人癌细胞增殖作用。其结构式为：

摘要： 本发明提供一种源于草酸青霉的黑麦酮酸类化合物Secalonic acid J及制备方法。该化合物具有抑制人癌细胞增殖作用，其结构式为：。通过发酵培养草酸青霉(Penicillium oxalicum)IBPT‑6，获取发酵物，然后从发酵物中分离纯化出该化合物。经实验证实，该化合物对人癌细胞具有较好的活性，可用于制备人癌细胞增殖抑制药物或抗肿瘤药物。

摘要： 本发明公开了Zaragozic acid A在产气荚膜梭菌Epsilon毒素中毒救治中的应用。本发明提供了Zaragozic acid A在如下任一中的应用：1)作为ETX毒素抑制剂；2)预防或治疗由ETX毒素引发的动物疾病；3)治疗由ETX毒素引发的疾病；4)抑制ETX毒素的毒性；5)中和ETX毒素。本发明的实验证明了，ZA对ETX毒素毒性中和效果很好。在细胞水平，ZA对ETX毒素的毒性有较好的抑制效果，在动物实验中，ZA显示出对ETX毒素攻毒后动物的强效保护效果。因此，ZA有望成为ETX毒素预防和治疗ETX毒素引起感染的重要试剂和药物。

摘要： 本发明公开了降解甾体化合物Phomopsic acid及其用途。本发明的化合物Phomopsic acid是从金线莲Anoectochilus roxburghii(Wall.)Lindl.叶片内生真菌Phomopsis sp.中分离得到的新的降解甾体类化合物。本发明采用光谱法、HRMS和计算方法确定了它们的结构。Phomopsic acid通过诱导Brd4降解，能够高效、低细胞毒性的激活潜伏期HIV，且Phomopsic acid能够使Brd4‑P‑TEFb复合物解离，降低Brd4对Tat的拮抗作用。这为逆转HIV潜伏期提供了一种新的先导化合物。

摘要： 本发明公开了降解甾体化合物Phomopsic acid及其用途。本发明的化合物Phomopsic acid是从金线莲Anoectochilus roxburghii(Wall.)Lindl.叶片内生真菌Phomopsis sp.中分离得到的新的降解甾体类化合物。本发明采用光谱法、HRMS和计算方法确定了它们的结构。Phomopsic acid通过诱导Brd4降解，能够高效、低细胞毒性的激活潜伏期HIV，且Phomopsic acid能够使Brd4‑P‑TEFb复合物解离，降低Brd4对Tat的拮抗作用。这为逆转HIV潜伏期提供了一种新的先导化合物。

摘要： 本发明涉及中药提取、分离领域，尤其涉及从马齿苋中提取、分离和鉴别出的新生物碱Oleraze（1）和Oleraoxazine acid（2）及其提取分离方法。所述的新化合物，分子式分别为C4H4N4O2、C6H5NO5，分别命名为Oleraze（1）和Oleraoxazine acid（2）。还提供上述新化合物的提取分离方法，水煎煮提取、硅胶柱层析、聚酰胺柱层析，硅胶柱层析，Sephadex LH‑20及HPLC进行分离纯化与制备，成功的分离得到新化合物。其结构采用1H‑NMR、13C‑NMR及二维核磁波谱解析的方法确定为新化合物。该两种化合物均具有潜在的抗炎活性，并提供制备方法，为开发新药和开发新成分提供先导物和理论依据。

摘要： 本发明公开了Zaragozic acid A在产气荚膜梭菌Epsilon毒素中毒救治中的应用。本发明提供了Zaragozic acid A在如下任一中的应用：1)作为ETX毒素抑制剂；2)预防或治疗由ETX毒素引发的动物疾病；3)治疗由ETX毒素引发的疾病；4)抑制ETX毒素的毒性；5)中和ETX毒素。本发明的实验证明了，ZA对ETX毒素毒性中和效果很好。在细胞水平，ZA对ETX毒素的毒性有较好的抑制效果，在动物实验中，ZA显示出对ETX毒素攻毒后动物的强效保护效果。因此，ZA有望成为ETX毒素预防和治疗ETX毒素引起感染的重要试剂和药物。

摘要： 本发明公开了Sorbic acid在制备抗冠状病毒感染药物中的应用，以及在制备冠状病毒3C样蛋白酶3Clpro抑制剂药物中的应用，Sorbic acid对冠状病毒的靶点3C样蛋白酶3Clpro的酶活性有较强抑制作用，具有发展为治疗和预防冠状病毒尤其是抗新冠病毒的药物的潜力。

摘要： 本发明公开了一种harzianic acid高产木霉菌株的构建方法，（1）以野生型木霉菌株基因组DNA为模板进行PCR扩增，获取hacI编码序列上游片段和hacI编码区部分片段，分别命名为UF和DF；（2）以质粒pUC19‑hph‑Ptef1为模板进行PCR扩增，获取包含潮霉素B磷酸转移酶元件hph和里氏木霉QM6a中tef1基因启动子序列的片段Ptef1，命名为hph‑Ptef1；（3）利用重叠PCR方法将上述3个片段按以下顺序连接，UF、hph‑Ptef1、DF获得超表达元件，命名为UF‑hph‑Ptef1‑DF；（4）将步骤（3）中超表达元件转入木霉菌的原生质体中，经潮霉素B筛选、PCR验证和HPLC检测后，获得高产harzianic acid的木霉菌株OEhacI。本发明的方法构建的harzianic acid高产菌株，在发酵4天即可在常规培养基PDB中摇瓶产生大量harzianic acid，从而为规模化生产harzianic acid提供有效开发技术和相应工程生产菌。

摘要： 本发明涉及体外诊断技术领域，具体涉及一种检测尿液中Calcitroic acid的方法及其应用。所述的检测方法包括：待测样本预处理；样本处理；绘制校准曲线：结果分析。本发明提供的优点：填补了Calcitroic acid定量方法的空白。检测时间短，具有特异性高、高通量、灵敏度高、抗干扰能力强、重现性好。试剂廉价易得；方法简单，利于推广。为Calcitroic acid在尿液中产生的机理研究奠定了方法学上的基础，并且为不同疾病模型当中生物标志物的研究提供了可靠的技术支撑。