AH_(2)O_(2)-induced oxidative stress injury cell model was established to investigate the antioxidant effect of nanoselenium on mouse spermatocyte lines and the regulation mechanism of the expression level and activit...AH_(2)O_(2)-induced oxidative stress injury cell model was established to investigate the antioxidant effect of nanoselenium on mouse spermatocyte lines and the regulation mechanism of the expression level and activity of seleniumcontaining antioxidant enzymes induced by oxidative stress.A safe and effective nano-drug system of functionalized selenium-containing nanoparticles(SeNPs)was developed with lentinan(LNT)(SeNPs@LNT).Mice spermatocyte line GC2-spg cells were treated with SeNPs@LNT(1,2,4,8,16,32μM)for 24-72 h to evaluate the cytotoxicity of selenium.GC2-spg cells were randomly divided into the following groups:control,hydrogen peroxide(H_(2)O_(2)),SeNPs@LNT,and H_(2)O_(2)+SeNPs@LNT groups.H_(2)O_(2)+SeNPs@LNT group was pretreated with SeNPs@LNT 4μM for 12 h,followed by H_(2)O_(2)600μM for 8 h.The cell viability decreased in the H_(2)O_(2) group and increased significantly in the SeNPs@LNT group.Compared with the H_(2)O_(2) group,the SeNPs@LNT+H_(2)O_(2) group exhibited obvious red fluorescence,indicating a higher level of mitochondrial membrane potential.The content of intracellular reactive oxygen species(ROS)in the SeNPs@LNT group reduced significantly,and the intensity of green fluorescence in the SeNPs@LNT+H_(2)O_(2) group decreased significantly compared with the H_(2)O_(2) group,indicating the inhibitory effect of SeNPs@LNT on the generation of ROS-induced oxidative stress.The activity of GPx and SOD increased significantly in the SeNPs@LNT group.The expression of p53 decreased significantly under the intervention of nano-selenium,and GPx1 expression increased.In the oxidative stress group,the expressions of DNA damage-related proteins and apoptosis-related proteins were higher than those in other groups.Thus,SeNPs@LNT can promote GC2-spg cell proliferation,improve GPx and SOD activities,remove intracellular ROS,and reduce mitochondrial damage and functional abnormalities caused by oxidative stress by regulating the ERK and p53 protein levels.SeNPs@LNT has good biological activity and antioxidant effect,which can be used to protect the male reproductive system from oxidative stress.展开更多
Background:Nano-selenium has been widely used in antiviral and anticancer therapy,and has the advantages of good targeting and low toxicity.For the first time,we combined male reproduction with nano-selenium to invest...Background:Nano-selenium has been widely used in antiviral and anticancer therapy,and has the advantages of good targeting and low toxicity.For the first time,we combined male reproduction with nano-selenium to investigate its antioxidant effect.This study investigated the protective effect of lentinan functionalized selenium nanoparticles on oxidative stress injury of the hydrogen peroxide(H_(2)O_(2))-induced Leydig cell line,TM3.Methods:The suitable concentration of nano-selenium treatment to promote cell proliferation was also discussed.The concentration of 4μM could significantly promote the growth of TM3 cells.Oxidative stress damage was caused using an 800μM concentration of hydrogen peroxide.The cells were divided into four groups:normal control group,oxidative stress treatment group,H_(2)O_(2)+SeNPs@LNT group,and SeNPs@LNT group.The H_(2)O_(2)+SeNPs@LNT group was pretreated with 4μM of SeNPs@LNT for 12 h,followed by 800μM of H_(2)O_(2)for 8 h.Results:Nano-selenium could significantly promote the proliferation and viability of TM3 cells.SeNPs@LNT treatment increased the level of mitochondrial membrane potential in normal cells and slowed down the decline in mitochondrial membrane potential level caused by oxidative stress injury.In addition,the increase in reactive oxygen species caused by oxidative stress was inhibited by SeNPs@LNT treatment.The apoptosis of TM3 cells was detected,and SeNPs@LNT alleviated the necrosis and apoptosis of TM3 cells induced by H_(2)O_(2).Nano-selenium plays a protective role against oxidative H_(2)O_(2)-induced stress injury in TM3 cells through the changes in the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway and P53 pathway,and the expression levels of other related proteins,protein kinase B(AKT)and C3.Conclusion:SeNPs@LNT exhibited good biological activity and antioxidant effect and can thus be used to protect the male reproductive system from oxidative stress.展开更多
Liver cancer is the seventh most common malignant tumor in the world and is the second highest cause of death due to cancer.Quercetin,a flavonoid with low toxicity,widely exists in various fruits and vegetables.It has...Liver cancer is the seventh most common malignant tumor in the world and is the second highest cause of death due to cancer.Quercetin,a flavonoid with low toxicity,widely exists in various fruits and vegetables.It has the potential to be a therapeutic agent against various cancers.This study aimed to demonstrate the anti-tumor effect of quercetin on HepG2 cells.Quercetin suppressed the HepG2 cell proliferation in a dose-dependent manner in cell viability assay.Induction of cell apoptosis was confirmed by apoptotic cells population(sub-G1 peak)detected by flow cytometer.A decrease in mitochondrial membrane potential and caspase-3 activation were also demonstrated in this study.Furthermore,quercetin induced HepG2 cell apoptosis through ROS-mediated phosphorylated ataxia-telangiectasia mutated,c-Jun Nterminal kinases,signal transducer,and activator of transcription 3(STAT-3),and Bax signaling pathways.These results suggest that quercetin has the potential to become an effective drug against the tumor.展开更多
BACKGROUND The incidence and mortality of liver cancer are among the highest of all malignant tumors in China.The high recurrence rate after conventional hepatectomy is worrying.There is a lack of effective prognostic...BACKGROUND The incidence and mortality of liver cancer are among the highest of all malignant tumors in China.The high recurrence rate after conventional hepatectomy is worrying.There is a lack of effective prognostic indicators for liver cancer.AIM To explore the clinical significance of preoperative serum oxidative stress and serum uric acid(UA)levels in hepatitis B-related liver cancer.METHODS The medical records of 110 hepatitis B-related liver cancer patients who under-went hepatectomy in Gansu Provincial Hospital were retrospectively analyzed.Recurrence in patients within 3 years after surgery was determined.The logistic regression model and Pearson or Spearman correlation were used to analyze the correlation between oxidative stress level and UA,and the recurrence of hepatitis B-related liver cancer.RESULTS Compared with the non-recurrence group,the levels of superoxide dismutase(SOD)and glutathione(GSH)in the recurrence group were lower and the levels of malondialdehyde(MDA)and UA were higher(all P<0.05).UA,SOD,MDA,and GSH were risk factors for postoperative recurrence in hepatitis B-related liver cancer patients(P<0.05).UA was positively correlated with MDA(r=0.395,P<0.001)and negatively correlated with GSH(r=-0.204,P=0.032).The area under the receiver operating characteristic curve(AUC)of SOD,MDA,GSH,and UA in predicting the prognosis was 0.276,0.910,0.199,and 0.784,respectively(all P<0.001).CONCLUSION The preoperative serum SOD,GSH,MDA,and UA levels had significant predictive effects on postoperative recurrence of hepatitis B-related liver cancer.展开更多
Circadian rhythms are natural rhythms that widely exist in all creatures,and regulate the processes and physiological functions of various biochemical reactions.The circadian clock is critical for cancer occurrence an...Circadian rhythms are natural rhythms that widely exist in all creatures,and regulate the processes and physiological functions of various biochemical reactions.The circadian clock is critical for cancer occurrence and progression.Its function is regulated by metabolic activities,and the expression and transcription of various genes.This review summarizes the composition of the circadian clock;the biological basis for its function;its relationship with,and mechanisms in,cancer;its various functions in different cancers;the effects of anti-tumor treatment;and potential therapeutic targets.Research in this area is expected to advance understanding of circadian locomotor output cycles kaput(CLOCK)and brain and muscle ARNT-like protein 1(BMAL1)in tumor diseases,and contribute to the development of new anti-tumor treatment strategies.展开更多
AIM:To investigate the value of combined detection of circulating cell-free DNA(cfDNA),a-fetal protein(AFP) and a L-fucosidase(AFU) for diagnosis of hepatocellular carcinoma(HCC).METHODS:Serum samples from 39 HCC pati...AIM:To investigate the value of combined detection of circulating cell-free DNA(cfDNA),a-fetal protein(AFP) and a L-fucosidase(AFU) for diagnosis of hepatocellular carcinoma(HCC).METHODS:Serum samples from 39 HCC patients and 45 normal controls were collected.Branched DNA(bDNA) was used to detect the level of cfDNA,and a receiver operating characteristic curve was employed to evaluate the diagnostic sensitivity,specificity,accuracy,positive predictive value,negative predictive value,positive likelihood ratio,negative likelihood ratio and Youden index,and to assess the diagnostic efficiency and their correlations with the clinicopathological features.AFP and AFU were detected by chemiluminescence and colorimetry,respectively.The significance of combined detection of the three biomarkers was discussed.RESULTS:cfDNA level was increased in 22 of the 39 HCC samples and in 2 of the 45 normal controls.cfDNA level in HCC samples was significantly higher than that in normal controls(P < 0.05).There were significant differences in sex and extra-and intrahepatic metastasis(P < 0.05).There was no significant correlation between cfDNA,AFP and AFU in the detection of HCC.The sensitivity of combined detection of cfDNA with one marker(AFP or AFU) and cfDNA with two markers(AFP and AFU) was 71.8%,87.2% and 89.7% vs 56.4%,53.8% and 66.7% for cfDNA,AFP and AFU used alone,respectively,the difference being statistically significant(P < 0.05).CONCLUSION:Quantitative analysis of cfDNA is sensitive and feasible,and the combined detection of cfDNA with AFP or AFU or both could improve the diagnostic sensitivity for HCC.展开更多
Objective To create transgenic rabbits by microinjecting human apolipoprotein A-Ⅱ (apoA-Ⅱ) gene into one-cell embryos, to study apoA-Ⅱ gene function on plasma lipoprotein metabolism and atherosclerosis. Methods S...Objective To create transgenic rabbits by microinjecting human apolipoprotein A-Ⅱ (apoA-Ⅱ) gene into one-cell embryos, to study apoA-Ⅱ gene function on plasma lipoprotein metabolism and atherosclerosis. Methods Superovulation and synchronization of estrus were induced in female Japanese White Rabbits by injecting hormone, then mating with male. After collected the fertilized eggs, the human apoA-Ⅱ gene was microinjected into the male pronucleus of eggs. The injected eggs were transferred into recipient female rabbits. Last, extract DNA from the new borns ear and determine whether the newborns were transgenic by polymerase chain reaction (PCR) or Southern blot analysis. Results A total of 822 embryos with microinjection of human apoAⅡ gene were implanted into 28 recipient rabbits. The number of surviving newborns was 37. 3 transgenic positive surviving founders were found with human apoA-Ⅱ.展开更多
AIM:To determine if blockade of P-selectin in the isolated blood-perfused cold ex vivo rat liver model protects the liver from ischemia-reperfusion injury. METHODS:The effect of P-selectin blockade was assessed by emp...AIM:To determine if blockade of P-selectin in the isolated blood-perfused cold ex vivo rat liver model protects the liver from ischemia-reperfusion injury. METHODS:The effect of P-selectin blockade was assessed by employing an isolated blood-perfused cold ex vivo rat liver with or without P-selectin antibody treatment before and after 6 h of cold storage in University of Wisconsin solution. RESULTS:In our isolated blood-perfused rat liver model,pre-treatment with P-selectin antibody failed to protect the liver from ischemia-reperfusion injury,as judged by the elevated aspartate aminotransferase activity. In addition,P-selectin antibody treatment did not significantly reduced hepatic polymorphonuclear leukocyte accumulation after 120 min of perfusion. Histological evaluation of liver sections obtained at 120 min of perfusion showed significant oncotic necrosis in liver sections of both ischemic control and P-selectin antibody-treated groups. However,total bile production after 120 min of perfusion was signifi cantly greater in P-selectin antibody-treated livers,compared to control livers. No signifi cant difference in P-selectin and ICAM-1 mRNAs and proteins,GSH,GSSG,and nuclear NF-κB was found between control and P-selectin antibody-treated livers. CONCLUSION:In conclusion,we have shown that blockade of P-selectin alone failed to reduced polymorphonuclear leukocyte accumulation in the liver and protect hepatocytes from ischemia-reperfusion injury in the isolated blood-perfused cold-ex vivo rat liver model.展开更多
The Ti substrates of IrO 2 -Ta 2 O 5 coated anodes were treated by solid-solution and aging, stress relieving annealing, and recrystallization annealing, and the coatings were prepared by thermal decomposition of a mi...The Ti substrates of IrO 2 -Ta 2 O 5 coated anodes were treated by solid-solution and aging, stress relieving annealing, and recrystallization annealing, and the coatings were prepared by thermal decomposition of a mixture of H 2 IrCl 6 ·6H 2 O dissolved in hydrochloric acid and TaCl 5 dissolved in alcohol. Scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and accelerated life test (ALT) were employed to study the microstructure and electrochemical properties of the anodes. Compared with the anode without heat treatment, the anodes with heat treatment are of higher electrochemical activity and longer accelerated life; especially, the anode with recrystallization annealing treatment has the best electrochemical properties and the longest accelerated life.展开更多
Carotenoids, which generate yellow, orange, and red colors, are crucial pigments in avian plumage. Investigations into genes associated with carotenoid- based coloration in avian species are important; however, such r...Carotenoids, which generate yellow, orange, and red colors, are crucial pigments in avian plumage. Investigations into genes associated with carotenoid- based coloration in avian species are important; however, such research is difficult because carotenoids cannot be synthetized in vertebrates as they are only derived from dietary sources. Here, the golden pheasant (Chrysolophus pictus) was used as a model in analysis of candidate gene expression profiles implicated in carotenoid binding and deposition. Using mass and Raman spectrometry to confirm the presence of carotenoids in golden pheasant feathers, we found C40H540 and C40H5602 in feathers with yellow to red colors, and in the rachis of iridescent feathers. The global gene expression profiles in golden pheasant skins were analyzed by RNA-seq and all six carotenoid binding candidate genes sequenced were studied by real- time PCR. STAR4, GSTA2, Scarbl, and APOD in feather follicles showed different expressions in red breast and orange nape feathers compared with that of iridescent mantle feathers. Further comparison of golden pheasant yellow rump and Lady Amherst's pheasant (Chrysolophus amherstiae) white nape feathers suggested that GSTA2 and APOD played a potential role in carotenoid-based coloration in golden pheasant.展开更多
Aim: To investigate the expression of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) and the possible mechanism in the development in androgen independent prostate cancer (AIPC). Methods:...Aim: To investigate the expression of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) and the possible mechanism in the development in androgen independent prostate cancer (AIPC). Methods: Immunohistochemistry was performed on paraffin-embedded sections with goat polyclonal against COX-2 and mouse monoclonal antibody against EGFR in 30 AIPC and 18 androgen dependent prostate cancer (ADPC) specimens. The effect of epidermal growth factor (EGF) treatments on the expression of COX-2 and signal pathway in PC-3 and DU-145 cells was studied using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. ELISA was used to measure prostaglandin E2 (PGE2) levels in the media of PC-3 and DU-145 incubated with EGF for 24 h. Results: COX-2 was positively expressed in AIPC and ADPC, which were predominantly in endochylema of prostate cancer (PCa) cells. Intense staining was seen in AIPC (80%) and in ADPC (55.5%), but there was no significant association between the two groups. EGFR expression was also positive in the two groups (61.8% in ADPC and 90% in AIPC, P 〈 0.01). A significant association was found between EGFR expression and a higher Gleason score (P 〈 0.05) or tumor stage (P 〈 0.05). The expression of PGE2 was increased in PC-3 and DU-145 cells after being incubated with EGF. Both p38MAPK and PI-3K pathway were involved in the PC-3 cell COX-2 upregulation course. In DU- 145, only p38MAPK pathway was associated with COX-2 upregulation. Conclusion: EGFR activation induces COX-2 expression through PI-3K and/or p38MAPK pathways. COX-2 and EGFR inhibitors might have a cooperative anti-tumor effect in PCa.展开更多
The Jingbaoshan platinum-palladium deposit is China’s largest independent PGM (platinum-group met- als) deposit so far discovered. There are eleven kinds of useful components in the ore: Pt, Pd, Os, Ir, Ru, Rh, Au, A...The Jingbaoshan platinum-palladium deposit is China’s largest independent PGM (platinum-group met- als) deposit so far discovered. There are eleven kinds of useful components in the ore: Pt, Pd, Os, Ir, Ru, Rh, Au, Ag, Cu, Ni, and Co. The platinum-group elements, gold and silver occur in the form of minerals in ores. twenty-five kinds of precious metal minerals have been found, of which twenty one belong to the platinum-group minerals. The minerals are very small in grain size. Copper occurs mainly as copper sulfide with a small amount of free copper oxide, and the beneficiated copper accounts for 95.21%. Nickel occurs mainly as nickel sulfide, and some nickel silicate and nickel oxide occur in the ore. The beneficiated nickel accounts for 72.03%. Cobalt occurs mainly as co- balt sulfide, and there are some cobalt oxide and other kinds of cobalt. The beneficiated cobalt accounts for 77.58%.展开更多
AIM: To evaluate the receptor protein which can specifically bind to β2GPⅠon the membrane of hepatocellular carcinoma (HCC) cell line SMMC-7721, and to study the biological function of the receptor.METHODS: Through ...AIM: To evaluate the receptor protein which can specifically bind to β2GPⅠon the membrane of hepatocellular carcinoma (HCC) cell line SMMC-7721, and to study the biological function of the receptor.METHODS: Through β2GPⅠ-affinity chromatography column, the peptid-polysome-mRNA complex, which can specially bind to β2GPⅠ, stayed with the column and was separated from the whole polysome of liver cells, and then eluted and collected. Using cDNA synthesis kit and cDNA PCR kit, the corresponding cDNA was obtained and sequenced. RT-PCR was used to amplify annexinⅡ, and flow cytometry was used to study the competitive binding of annexinⅡ with β2GPⅠto SMMC-7721.RESULTS: A total of 1.1 kb of the cDNA fragment of the specific binding protein of β2GPⅠon liver cell membrane was obtained. The sequence of cDNA shared high homology with human annexinⅡ (98%). AnnexinⅡ was expressed on the membrane of SMMC-7721, and could compete with β2GPⅠfor combining with SMMC-7721.CONCLUSION: The receptor for β2GPⅠon membrane of SMMC-7721 cells is annexinⅡ, which might bridge HBV to infect hepatocytes.展开更多
In order to improve the anti-oxidation property of carbon/carbon (C/C) composites, a novel SiC-Si-ZrSiO4 multiphase oxidation protective coating was produced on the surface of C/SiC coated carbon/carbon compo ites b...In order to improve the anti-oxidation property of carbon/carbon (C/C) composites, a novel SiC-Si-ZrSiO4 multiphase oxidation protective coating was produced on the surface of C/SiC coated carbon/carbon compo ites by a pack cementation technique. The phase composition and microstructure of the as-prepared coatings were characterized by XRD (X-ray diffraction), SEM (scanning electron microscopy) and EDS (energy dispersive spectroscopy). Oxidation behavior of the multiphase coated C/C composites was also investigated. It showed that the as-prepared coating characterized by excellent oxidation resistance and thermal shock re- sistance could effectively protect C/C composites from oxidation at 1773 K for 57 h in air and endure the thermal cycle between 1773 K and room temperature for 12 times, whereas the corresponding weight loss is only 1.47%. The excellent oxidation protective ability of the SiC-Si-ZrSiO4 coating could be attributed to the C/SiC gradient inner layer and the multiphase microstructure of the coating.展开更多
The CRISPR/Cas9 mediates efficient gene editing but has off-target effects inconducive to animal breeding. In this study, the efficacy of CRISPR/Cas9 vectors containing different lengths of g RNA in reduction of the o...The CRISPR/Cas9 mediates efficient gene editing but has off-target effects inconducive to animal breeding. In this study, the efficacy of CRISPR/Cas9 vectors containing different lengths of g RNA in reduction of the off-target phenomenon in the bovine MSTN gene knockout fibroblast cell lines was assessed, providing insight into improved methods for livestock breeding. A 20-bp g RNA was designed for the second exon of the bovine MSTN gene, and CRISPR/Cas9-B was constructed to guide the Cas9 protein to the AGAACCAGGAGAAGATGGACTGG site. The alternative CRISPR/Cas9-19, CRISPR/Cas9-18, CRISPR/Cas9-17 and CRISPR/Cas9-15 vectors were constructed using g RNAs truncated by 1, 2, 3 and 5 bp, respectively. These vectors were then introduced into bovine fetal fibroblasts by the electroporation method, and single cells were obtained by flow cytometry sorting. PCR was performed for each off-target site. All samples were sequenced and analyzed, and finally the efficiency of each vector in target and off-target sites was compared. The CRISPR/Cas9-B vector successfully knocked out the MSTN gene, but the off-target phenomenon was observed. The efficiencies of CRISPR/Cas-B, CRISPR/Cas9-19, CRISPR/Cas9-18, CRISPR/Cas9-17 and CRISPR/Cas9-15 in triggering gene mutations at MSTN targeting sites were 62.16, 17.39, 7.69, 74.29 and 3.85%, respectively;rates of each at the Off-MSTN-1 locus were 52.86, 0, 0, 8.82 and 0%, respectively;all were 0% at the Off-MSTN-2 locus;rates at the Off-MSTN-3 site were 44.87, 51.72, 86.36, 0 and 50%, respectively. The efficiency of the CRISPR/Cas9-17 plasmid in the MSTN site was higher than that in the CRISPR/Cas9-B plasmid, and the effect at the three off-target sites was significantly lower. This study demonstrated that the CRISPR/Cas9-17 plasmid constructed by truncating 3 bp g RNA can effectively reduce the off-target effect without reducing the efficiency of bovine MSTN gene targeting. This finding will provide more effective gene editing strategy for use of CRISPR/Cas9 technology.展开更多
Cholate-CoA ligase(CCL) and bile acid-CoA:amino acid N-acyltransferase(BAAT) sequentially mediate bile-acid amidation.Defects can cause intrahepatic cholestasis.Distinction has required gene sequencing.We assessed pot...Cholate-CoA ligase(CCL) and bile acid-CoA:amino acid N-acyltransferase(BAAT) sequentially mediate bile-acid amidation.Defects can cause intrahepatic cholestasis.Distinction has required gene sequencing.We assessed potential clinical utility of immunostaining of liver for CCL and BAAT.Using commercially available antibodies against BAAT and CCL,we immunostained liver from an infant with jaundice,deficiency of amidated bile acids,and transcription-terminating mutation in BAAT.CCL was normally expressed.BAAT expression was not detected.Immunostaining may facilitate diagnosis in bileacid amidation defects.展开更多
The coupling of local surface plasmon (LSP) of nanoparticle and surface plasmon (SP) mode produced by metal film can lead to the enhanced electromagnetic field, which has an important application in enhancing the ...The coupling of local surface plasmon (LSP) of nanoparticle and surface plasmon (SP) mode produced by metal film can lead to the enhanced electromagnetic field, which has an important application in enhancing the fluorescence of quantum dots (QDs). Herein, the Ag nanocube and Ag film are used to enhance the fluorescence of CdSe QDs. The enhancement is found to relate to the sizes of the Ag nanocube and the thickness of the Ag film. Moreover, we also present the fluorescence enhancement caused by only SP. The result shows that the coupling between metal nanoparticles and metal film can realize larger field enhancement. Numerical simulation verifies that a nanocube can localize a strong electric field around its comer. All the results indicate that the fluorescence of QDs can be efficiently improved by optimizing the parameters of Ag film and Ag cubes.展开更多
BACKGROUND Biliary diseases are common digestive system disorders which may combine with biliary tract infection such as cholecystitis or cholangitis.Thus,rapid identification of the bacteria and their antibiotic susc...BACKGROUND Biliary diseases are common digestive system disorders which may combine with biliary tract infection such as cholecystitis or cholangitis.Thus,rapid identification of the bacteria and their antibiotic susceptibility profiles are crucial for reducing the mortality of patients with biliary tract infection.AIM To identify bacterial species and antibiotic susceptibility for antibacterial therapy and analyze bile cultivation risk factors for increasing detection rates.METHODS This retrospective study was conducted from July 2008 to July 2017.In total,1339 bile samples which were collected during therapeutic endoscopic retrograde cholangiopan-creatography or percutaneous transhepatic cholangiodrainage or other biliary surgeries or biliary drainage were obtained to characterize pathogen spectra,antibiotic susceptibility,and clinical features.Clinical data including age,sex,comorbidities,clinical symptoms,protopathies,and history of biliary tract diseases and surgeries were collated from hospital medical records.Species identification and initial drug susceptibility were further identified by biochemical characterization using the VITEK 2 Compact test.RESULTS Positive microbiological findings were observed in 738 samples.The most frequently encountered strains were gram-negative bacteria(74.94%),including Escherichia coli(37.78%),Pseudomonas aeruginosa(8.96%),and Klebsiella pneumoniae(10.29%).Bile bacteria were largely sensitive to carbapenems,piperacillin/tazobactam,and gentamicin.Gram-negative strains had low susceptibility to ceftriaxone,quinolones and ampicillin.Almost the same microorganisms were present in patients with malignant and benign diseases.The number of samples with Klebsiella pneumoniae in the bile culture were significantly different between patients with malignant and benign diseases(55 vs 30;P=0.019).Age(P<0.001),fever(P<0.001),history of biliary tract diseases and surgeries(both P<0.001),benign disease(P=0.002),and the comorbidity chronic renal insufficiency(P=0.007)affected the positive rates of the bile samples.CONCLUSION Gram-negative bacteria were the most commonly isolated biliary bacteria.We determined the major factors associated with positive detection rates.Microbiological analysis of bile samples allowed accurate antibiotic treatments.展开更多
There is a consensus in the aerospace field that the development of reusable liquid rockets can effectively reduce the launch expense.The pursuit of a long service life and reutilization highly depends on the bearing ...There is a consensus in the aerospace field that the development of reusable liquid rockets can effectively reduce the launch expense.The pursuit of a long service life and reutilization highly depends on the bearing components.However,the rolling element bearings(REBs)used in the existing rocket turbopumps present obvious and increasing limitations due to their mechanical contacting mode.For REBs,high rotational speed and long service life are two performance indexes that mutually restrict each other.To go beyond the DN value(the product of the bearing bore and rotational speed)limit of REBs,the major space powers have conducted substantial explorations on the use of new types of bearings to replace the REB.This review discusses,first,the crucial role of bearings in rocket turbopumps and the related structural improvements of REBs.Then,with the prospect of application to the next generation of reusable liquid rocket turbopumps,the bearing candidates investigated by major space powers are summarized comprehensively.These promising alternatives to REBs include fluid-film,foil,and magnetic bearings,together with the novel superconducting compound bearings recently proposed by our team.Our more than ten years of relevant research on fluid-film and magnetic bearings are also introduced.This review is meaningful for the development of long-life and highly reliable bearings to be used in future reusable rocket turbopumps.展开更多
基金funded by the open Project of Guangdong Key Laboratory of Marine Materia(LMM2020-7)the science and technology projects in Guangzhou(202201020632,202201020638,202206010100,202201020655 and 202102010202)+2 种基金the Guangdong Natural Science Foundation(2020A1515110648)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(2020A03)The Guangzhou Medical University Students’Science and Technology Innovation Project(02-408-2203-2079,2021AEK119).
文摘AH_(2)O_(2)-induced oxidative stress injury cell model was established to investigate the antioxidant effect of nanoselenium on mouse spermatocyte lines and the regulation mechanism of the expression level and activity of seleniumcontaining antioxidant enzymes induced by oxidative stress.A safe and effective nano-drug system of functionalized selenium-containing nanoparticles(SeNPs)was developed with lentinan(LNT)(SeNPs@LNT).Mice spermatocyte line GC2-spg cells were treated with SeNPs@LNT(1,2,4,8,16,32μM)for 24-72 h to evaluate the cytotoxicity of selenium.GC2-spg cells were randomly divided into the following groups:control,hydrogen peroxide(H_(2)O_(2)),SeNPs@LNT,and H_(2)O_(2)+SeNPs@LNT groups.H_(2)O_(2)+SeNPs@LNT group was pretreated with SeNPs@LNT 4μM for 12 h,followed by H_(2)O_(2)600μM for 8 h.The cell viability decreased in the H_(2)O_(2) group and increased significantly in the SeNPs@LNT group.Compared with the H_(2)O_(2) group,the SeNPs@LNT+H_(2)O_(2) group exhibited obvious red fluorescence,indicating a higher level of mitochondrial membrane potential.The content of intracellular reactive oxygen species(ROS)in the SeNPs@LNT group reduced significantly,and the intensity of green fluorescence in the SeNPs@LNT+H_(2)O_(2) group decreased significantly compared with the H_(2)O_(2) group,indicating the inhibitory effect of SeNPs@LNT on the generation of ROS-induced oxidative stress.The activity of GPx and SOD increased significantly in the SeNPs@LNT group.The expression of p53 decreased significantly under the intervention of nano-selenium,and GPx1 expression increased.In the oxidative stress group,the expressions of DNA damage-related proteins and apoptosis-related proteins were higher than those in other groups.Thus,SeNPs@LNT can promote GC2-spg cell proliferation,improve GPx and SOD activities,remove intracellular ROS,and reduce mitochondrial damage and functional abnormalities caused by oxidative stress by regulating the ERK and p53 protein levels.SeNPs@LNT has good biological activity and antioxidant effect,which can be used to protect the male reproductive system from oxidative stress.
基金Science and Technology Projects in Guangzhou(202201020632,202201020638,202206010100,202201020655,and 202102010202)the Guangdong Natural Science Foundation(2020A1515110648)+2 种基金the Open Project of Guangdong Key Laboratory of Marine Materia(LMM2020-7)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(2020A03)the Guangzhou Medical University Students’Science and Technology Innovation Project(2021AEK119 and 02-408-2203-2079).
文摘Background:Nano-selenium has been widely used in antiviral and anticancer therapy,and has the advantages of good targeting and low toxicity.For the first time,we combined male reproduction with nano-selenium to investigate its antioxidant effect.This study investigated the protective effect of lentinan functionalized selenium nanoparticles on oxidative stress injury of the hydrogen peroxide(H_(2)O_(2))-induced Leydig cell line,TM3.Methods:The suitable concentration of nano-selenium treatment to promote cell proliferation was also discussed.The concentration of 4μM could significantly promote the growth of TM3 cells.Oxidative stress damage was caused using an 800μM concentration of hydrogen peroxide.The cells were divided into four groups:normal control group,oxidative stress treatment group,H_(2)O_(2)+SeNPs@LNT group,and SeNPs@LNT group.The H_(2)O_(2)+SeNPs@LNT group was pretreated with 4μM of SeNPs@LNT for 12 h,followed by 800μM of H_(2)O_(2)for 8 h.Results:Nano-selenium could significantly promote the proliferation and viability of TM3 cells.SeNPs@LNT treatment increased the level of mitochondrial membrane potential in normal cells and slowed down the decline in mitochondrial membrane potential level caused by oxidative stress injury.In addition,the increase in reactive oxygen species caused by oxidative stress was inhibited by SeNPs@LNT treatment.The apoptosis of TM3 cells was detected,and SeNPs@LNT alleviated the necrosis and apoptosis of TM3 cells induced by H_(2)O_(2).Nano-selenium plays a protective role against oxidative H_(2)O_(2)-induced stress injury in TM3 cells through the changes in the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway and P53 pathway,and the expression levels of other related proteins,protein kinase B(AKT)and C3.Conclusion:SeNPs@LNT exhibited good biological activity and antioxidant effect and can thus be used to protect the male reproductive system from oxidative stress.
基金This work was supported by theGuangdong Natural Science Foundation(2020A1515110648)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(2020A03)+2 种基金the Technology Planning Project of Guangzhou(202102010202 and 202201020655)the Open Project of Guangdong Key Laboratory of Marine Materia Medica(LMM2020-7)the Guangzhou Medical University Students’Science and Technology Innovation Project(02-408-2203-2079,2021AEK119,2021AEK122,2021AEK125 and 2021AEK128).
文摘Liver cancer is the seventh most common malignant tumor in the world and is the second highest cause of death due to cancer.Quercetin,a flavonoid with low toxicity,widely exists in various fruits and vegetables.It has the potential to be a therapeutic agent against various cancers.This study aimed to demonstrate the anti-tumor effect of quercetin on HepG2 cells.Quercetin suppressed the HepG2 cell proliferation in a dose-dependent manner in cell viability assay.Induction of cell apoptosis was confirmed by apoptotic cells population(sub-G1 peak)detected by flow cytometer.A decrease in mitochondrial membrane potential and caspase-3 activation were also demonstrated in this study.Furthermore,quercetin induced HepG2 cell apoptosis through ROS-mediated phosphorylated ataxia-telangiectasia mutated,c-Jun Nterminal kinases,signal transducer,and activator of transcription 3(STAT-3),and Bax signaling pathways.These results suggest that quercetin has the potential to become an effective drug against the tumor.
基金Supported by the Gansu Health Industry Research Plan Project,No.GSWSKY-2019-16Lanzhou Science and Technology Development Plan Project,No.2019-ZD-101.
文摘BACKGROUND The incidence and mortality of liver cancer are among the highest of all malignant tumors in China.The high recurrence rate after conventional hepatectomy is worrying.There is a lack of effective prognostic indicators for liver cancer.AIM To explore the clinical significance of preoperative serum oxidative stress and serum uric acid(UA)levels in hepatitis B-related liver cancer.METHODS The medical records of 110 hepatitis B-related liver cancer patients who under-went hepatectomy in Gansu Provincial Hospital were retrospectively analyzed.Recurrence in patients within 3 years after surgery was determined.The logistic regression model and Pearson or Spearman correlation were used to analyze the correlation between oxidative stress level and UA,and the recurrence of hepatitis B-related liver cancer.RESULTS Compared with the non-recurrence group,the levels of superoxide dismutase(SOD)and glutathione(GSH)in the recurrence group were lower and the levels of malondialdehyde(MDA)and UA were higher(all P<0.05).UA,SOD,MDA,and GSH were risk factors for postoperative recurrence in hepatitis B-related liver cancer patients(P<0.05).UA was positively correlated with MDA(r=0.395,P<0.001)and negatively correlated with GSH(r=-0.204,P=0.032).The area under the receiver operating characteristic curve(AUC)of SOD,MDA,GSH,and UA in predicting the prognosis was 0.276,0.910,0.199,and 0.784,respectively(all P<0.001).CONCLUSION The preoperative serum SOD,GSH,MDA,and UA levels had significant predictive effects on postoperative recurrence of hepatitis B-related liver cancer.
基金supported by the National Science Foundation of China[grant number 42025503]the National Key R&D Program of China[grant number 2018YFA0605604]the Key Innovation Team of the China Meteorological Administration[grant number CMA2022ZD03].
基金supported by the National Natural Science Foundation of China(Grant Nos.81621003,32000533,82073059,and 81872020)。
文摘Circadian rhythms are natural rhythms that widely exist in all creatures,and regulate the processes and physiological functions of various biochemical reactions.The circadian clock is critical for cancer occurrence and progression.Its function is regulated by metabolic activities,and the expression and transcription of various genes.This review summarizes the composition of the circadian clock;the biological basis for its function;its relationship with,and mechanisms in,cancer;its various functions in different cancers;the effects of anti-tumor treatment;and potential therapeutic targets.Research in this area is expected to advance understanding of circadian locomotor output cycles kaput(CLOCK)and brain and muscle ARNT-like protein 1(BMAL1)in tumor diseases,and contribute to the development of new anti-tumor treatment strategies.
文摘AIM:To investigate the value of combined detection of circulating cell-free DNA(cfDNA),a-fetal protein(AFP) and a L-fucosidase(AFU) for diagnosis of hepatocellular carcinoma(HCC).METHODS:Serum samples from 39 HCC patients and 45 normal controls were collected.Branched DNA(bDNA) was used to detect the level of cfDNA,and a receiver operating characteristic curve was employed to evaluate the diagnostic sensitivity,specificity,accuracy,positive predictive value,negative predictive value,positive likelihood ratio,negative likelihood ratio and Youden index,and to assess the diagnostic efficiency and their correlations with the clinicopathological features.AFP and AFU were detected by chemiluminescence and colorimetry,respectively.The significance of combined detection of the three biomarkers was discussed.RESULTS:cfDNA level was increased in 22 of the 39 HCC samples and in 2 of the 45 normal controls.cfDNA level in HCC samples was significantly higher than that in normal controls(P < 0.05).There were significant differences in sex and extra-and intrahepatic metastasis(P < 0.05).There was no significant correlation between cfDNA,AFP and AFU in the detection of HCC.The sensitivity of combined detection of cfDNA with one marker(AFP or AFU) and cfDNA with two markers(AFP and AFU) was 71.8%,87.2% and 89.7% vs 56.4%,53.8% and 66.7% for cfDNA,AFP and AFU used alone,respectively,the difference being statistically significant(P < 0.05).CONCLUSION:Quantitative analysis of cfDNA is sensitive and feasible,and the combined detection of cfDNA with AFP or AFU or both could improve the diagnostic sensitivity for HCC.
文摘Objective To create transgenic rabbits by microinjecting human apolipoprotein A-Ⅱ (apoA-Ⅱ) gene into one-cell embryos, to study apoA-Ⅱ gene function on plasma lipoprotein metabolism and atherosclerosis. Methods Superovulation and synchronization of estrus were induced in female Japanese White Rabbits by injecting hormone, then mating with male. After collected the fertilized eggs, the human apoA-Ⅱ gene was microinjected into the male pronucleus of eggs. The injected eggs were transferred into recipient female rabbits. Last, extract DNA from the new borns ear and determine whether the newborns were transgenic by polymerase chain reaction (PCR) or Southern blot analysis. Results A total of 822 embryos with microinjection of human apoAⅡ gene were implanted into 28 recipient rabbits. The number of surviving newborns was 37. 3 transgenic positive surviving founders were found with human apoA-Ⅱ.
基金Supported by Grants from the American Liver Foundation, Naomi Judd Liver Scholar Award, The American Surgical Association Career Development Fellowship, and National Ⅰ
文摘AIM:To determine if blockade of P-selectin in the isolated blood-perfused cold ex vivo rat liver model protects the liver from ischemia-reperfusion injury. METHODS:The effect of P-selectin blockade was assessed by employing an isolated blood-perfused cold ex vivo rat liver with or without P-selectin antibody treatment before and after 6 h of cold storage in University of Wisconsin solution. RESULTS:In our isolated blood-perfused rat liver model,pre-treatment with P-selectin antibody failed to protect the liver from ischemia-reperfusion injury,as judged by the elevated aspartate aminotransferase activity. In addition,P-selectin antibody treatment did not significantly reduced hepatic polymorphonuclear leukocyte accumulation after 120 min of perfusion. Histological evaluation of liver sections obtained at 120 min of perfusion showed significant oncotic necrosis in liver sections of both ischemic control and P-selectin antibody-treated groups. However,total bile production after 120 min of perfusion was signifi cantly greater in P-selectin antibody-treated livers,compared to control livers. No signifi cant difference in P-selectin and ICAM-1 mRNAs and proteins,GSH,GSSG,and nuclear NF-κB was found between control and P-selectin antibody-treated livers. CONCLUSION:In conclusion,we have shown that blockade of P-selectin alone failed to reduced polymorphonuclear leukocyte accumulation in the liver and protect hepatocytes from ischemia-reperfusion injury in the isolated blood-perfused cold-ex vivo rat liver model.
文摘The Ti substrates of IrO 2 -Ta 2 O 5 coated anodes were treated by solid-solution and aging, stress relieving annealing, and recrystallization annealing, and the coatings were prepared by thermal decomposition of a mixture of H 2 IrCl 6 ·6H 2 O dissolved in hydrochloric acid and TaCl 5 dissolved in alcohol. Scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and accelerated life test (ALT) were employed to study the microstructure and electrochemical properties of the anodes. Compared with the anode without heat treatment, the anodes with heat treatment are of higher electrochemical activity and longer accelerated life; especially, the anode with recrystallization annealing treatment has the best electrochemical properties and the longest accelerated life.
基金supported by the 2014 Fundamental Research Program from Science and Technology of the Inner Mongolia Autonomous Region of China
文摘Carotenoids, which generate yellow, orange, and red colors, are crucial pigments in avian plumage. Investigations into genes associated with carotenoid- based coloration in avian species are important; however, such research is difficult because carotenoids cannot be synthetized in vertebrates as they are only derived from dietary sources. Here, the golden pheasant (Chrysolophus pictus) was used as a model in analysis of candidate gene expression profiles implicated in carotenoid binding and deposition. Using mass and Raman spectrometry to confirm the presence of carotenoids in golden pheasant feathers, we found C40H540 and C40H5602 in feathers with yellow to red colors, and in the rachis of iridescent feathers. The global gene expression profiles in golden pheasant skins were analyzed by RNA-seq and all six carotenoid binding candidate genes sequenced were studied by real- time PCR. STAR4, GSTA2, Scarbl, and APOD in feather follicles showed different expressions in red breast and orange nape feathers compared with that of iridescent mantle feathers. Further comparison of golden pheasant yellow rump and Lady Amherst's pheasant (Chrysolophus amherstiae) white nape feathers suggested that GSTA2 and APOD played a potential role in carotenoid-based coloration in golden pheasant.
文摘Aim: To investigate the expression of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) and the possible mechanism in the development in androgen independent prostate cancer (AIPC). Methods: Immunohistochemistry was performed on paraffin-embedded sections with goat polyclonal against COX-2 and mouse monoclonal antibody against EGFR in 30 AIPC and 18 androgen dependent prostate cancer (ADPC) specimens. The effect of epidermal growth factor (EGF) treatments on the expression of COX-2 and signal pathway in PC-3 and DU-145 cells was studied using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. ELISA was used to measure prostaglandin E2 (PGE2) levels in the media of PC-3 and DU-145 incubated with EGF for 24 h. Results: COX-2 was positively expressed in AIPC and ADPC, which were predominantly in endochylema of prostate cancer (PCa) cells. Intense staining was seen in AIPC (80%) and in ADPC (55.5%), but there was no significant association between the two groups. EGFR expression was also positive in the two groups (61.8% in ADPC and 90% in AIPC, P 〈 0.01). A significant association was found between EGFR expression and a higher Gleason score (P 〈 0.05) or tumor stage (P 〈 0.05). The expression of PGE2 was increased in PC-3 and DU-145 cells after being incubated with EGF. Both p38MAPK and PI-3K pathway were involved in the PC-3 cell COX-2 upregulation course. In DU- 145, only p38MAPK pathway was associated with COX-2 upregulation. Conclusion: EGFR activation induces COX-2 expression through PI-3K and/or p38MAPK pathways. COX-2 and EGFR inhibitors might have a cooperative anti-tumor effect in PCa.
文摘The Jingbaoshan platinum-palladium deposit is China’s largest independent PGM (platinum-group met- als) deposit so far discovered. There are eleven kinds of useful components in the ore: Pt, Pd, Os, Ir, Ru, Rh, Au, Ag, Cu, Ni, and Co. The platinum-group elements, gold and silver occur in the form of minerals in ores. twenty-five kinds of precious metal minerals have been found, of which twenty one belong to the platinum-group minerals. The minerals are very small in grain size. Copper occurs mainly as copper sulfide with a small amount of free copper oxide, and the beneficiated copper accounts for 95.21%. Nickel occurs mainly as nickel sulfide, and some nickel silicate and nickel oxide occur in the ore. The beneficiated nickel accounts for 72.03%. Cobalt occurs mainly as co- balt sulfide, and there are some cobalt oxide and other kinds of cobalt. The beneficiated cobalt accounts for 77.58%.
基金Supported by The National Nature Science Foundation of China,No. 30070338
文摘AIM: To evaluate the receptor protein which can specifically bind to β2GPⅠon the membrane of hepatocellular carcinoma (HCC) cell line SMMC-7721, and to study the biological function of the receptor.METHODS: Through β2GPⅠ-affinity chromatography column, the peptid-polysome-mRNA complex, which can specially bind to β2GPⅠ, stayed with the column and was separated from the whole polysome of liver cells, and then eluted and collected. Using cDNA synthesis kit and cDNA PCR kit, the corresponding cDNA was obtained and sequenced. RT-PCR was used to amplify annexinⅡ, and flow cytometry was used to study the competitive binding of annexinⅡ with β2GPⅠto SMMC-7721.RESULTS: A total of 1.1 kb of the cDNA fragment of the specific binding protein of β2GPⅠon liver cell membrane was obtained. The sequence of cDNA shared high homology with human annexinⅡ (98%). AnnexinⅡ was expressed on the membrane of SMMC-7721, and could compete with β2GPⅠfor combining with SMMC-7721.CONCLUSION: The receptor for β2GPⅠon membrane of SMMC-7721 cells is annexinⅡ, which might bridge HBV to infect hepatocytes.
基金supported by the National Natural Science Foundation of China under Grant No.90716024the"111"Introducing Intelligence Project under Grant No.08040.
文摘In order to improve the anti-oxidation property of carbon/carbon (C/C) composites, a novel SiC-Si-ZrSiO4 multiphase oxidation protective coating was produced on the surface of C/SiC coated carbon/carbon compo ites by a pack cementation technique. The phase composition and microstructure of the as-prepared coatings were characterized by XRD (X-ray diffraction), SEM (scanning electron microscopy) and EDS (energy dispersive spectroscopy). Oxidation behavior of the multiphase coated C/C composites was also investigated. It showed that the as-prepared coating characterized by excellent oxidation resistance and thermal shock re- sistance could effectively protect C/C composites from oxidation at 1773 K for 57 h in air and endure the thermal cycle between 1773 K and room temperature for 12 times, whereas the corresponding weight loss is only 1.47%. The excellent oxidation protective ability of the SiC-Si-ZrSiO4 coating could be attributed to the C/SiC gradient inner layer and the multiphase microstructure of the coating.
基金supported by the National Transgenic Project of China (2016ZX08010001-002 and 2016ZX08010005-001)the National Natural Science Foundation of China (81471001)the Inner Mongolia Science and Technology Program, China (201502073)
文摘The CRISPR/Cas9 mediates efficient gene editing but has off-target effects inconducive to animal breeding. In this study, the efficacy of CRISPR/Cas9 vectors containing different lengths of g RNA in reduction of the off-target phenomenon in the bovine MSTN gene knockout fibroblast cell lines was assessed, providing insight into improved methods for livestock breeding. A 20-bp g RNA was designed for the second exon of the bovine MSTN gene, and CRISPR/Cas9-B was constructed to guide the Cas9 protein to the AGAACCAGGAGAAGATGGACTGG site. The alternative CRISPR/Cas9-19, CRISPR/Cas9-18, CRISPR/Cas9-17 and CRISPR/Cas9-15 vectors were constructed using g RNAs truncated by 1, 2, 3 and 5 bp, respectively. These vectors were then introduced into bovine fetal fibroblasts by the electroporation method, and single cells were obtained by flow cytometry sorting. PCR was performed for each off-target site. All samples were sequenced and analyzed, and finally the efficiency of each vector in target and off-target sites was compared. The CRISPR/Cas9-B vector successfully knocked out the MSTN gene, but the off-target phenomenon was observed. The efficiencies of CRISPR/Cas-B, CRISPR/Cas9-19, CRISPR/Cas9-18, CRISPR/Cas9-17 and CRISPR/Cas9-15 in triggering gene mutations at MSTN targeting sites were 62.16, 17.39, 7.69, 74.29 and 3.85%, respectively;rates of each at the Off-MSTN-1 locus were 52.86, 0, 0, 8.82 and 0%, respectively;all were 0% at the Off-MSTN-2 locus;rates at the Off-MSTN-3 site were 44.87, 51.72, 86.36, 0 and 50%, respectively. The efficiency of the CRISPR/Cas9-17 plasmid in the MSTN site was higher than that in the CRISPR/Cas9-B plasmid, and the effect at the three off-target sites was significantly lower. This study demonstrated that the CRISPR/Cas9-17 plasmid constructed by truncating 3 bp g RNA can effectively reduce the off-target effect without reducing the efficiency of bovine MSTN gene targeting. This finding will provide more effective gene editing strategy for use of CRISPR/Cas9 technology.
基金Supported by Great Ormond Street Hospital Children’s Charity, to Clayton PTNational Institutes of HealthGrant R01 DK58214, to Bull LN
文摘Cholate-CoA ligase(CCL) and bile acid-CoA:amino acid N-acyltransferase(BAAT) sequentially mediate bile-acid amidation.Defects can cause intrahepatic cholestasis.Distinction has required gene sequencing.We assessed potential clinical utility of immunostaining of liver for CCL and BAAT.Using commercially available antibodies against BAAT and CCL,we immunostained liver from an infant with jaundice,deficiency of amidated bile acids,and transcription-terminating mutation in BAAT.CCL was normally expressed.BAAT expression was not detected.Immunostaining may facilitate diagnosis in bileacid amidation defects.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51272246 and 81172082)the Fundamental Research Funds for the Central Universities,China(Grant No.2030000001)
文摘The coupling of local surface plasmon (LSP) of nanoparticle and surface plasmon (SP) mode produced by metal film can lead to the enhanced electromagnetic field, which has an important application in enhancing the fluorescence of quantum dots (QDs). Herein, the Ag nanocube and Ag film are used to enhance the fluorescence of CdSe QDs. The enhancement is found to relate to the sizes of the Ag nanocube and the thickness of the Ag film. Moreover, we also present the fluorescence enhancement caused by only SP. The result shows that the coupling between metal nanoparticles and metal film can realize larger field enhancement. Numerical simulation verifies that a nanocube can localize a strong electric field around its comer. All the results indicate that the fluorescence of QDs can be efficiently improved by optimizing the parameters of Ag film and Ag cubes.
基金National Natural Science Foundation of China,No.81802071.
文摘BACKGROUND Biliary diseases are common digestive system disorders which may combine with biliary tract infection such as cholecystitis or cholangitis.Thus,rapid identification of the bacteria and their antibiotic susceptibility profiles are crucial for reducing the mortality of patients with biliary tract infection.AIM To identify bacterial species and antibiotic susceptibility for antibacterial therapy and analyze bile cultivation risk factors for increasing detection rates.METHODS This retrospective study was conducted from July 2008 to July 2017.In total,1339 bile samples which were collected during therapeutic endoscopic retrograde cholangiopan-creatography or percutaneous transhepatic cholangiodrainage or other biliary surgeries or biliary drainage were obtained to characterize pathogen spectra,antibiotic susceptibility,and clinical features.Clinical data including age,sex,comorbidities,clinical symptoms,protopathies,and history of biliary tract diseases and surgeries were collated from hospital medical records.Species identification and initial drug susceptibility were further identified by biochemical characterization using the VITEK 2 Compact test.RESULTS Positive microbiological findings were observed in 738 samples.The most frequently encountered strains were gram-negative bacteria(74.94%),including Escherichia coli(37.78%),Pseudomonas aeruginosa(8.96%),and Klebsiella pneumoniae(10.29%).Bile bacteria were largely sensitive to carbapenems,piperacillin/tazobactam,and gentamicin.Gram-negative strains had low susceptibility to ceftriaxone,quinolones and ampicillin.Almost the same microorganisms were present in patients with malignant and benign diseases.The number of samples with Klebsiella pneumoniae in the bile culture were significantly different between patients with malignant and benign diseases(55 vs 30;P=0.019).Age(P<0.001),fever(P<0.001),history of biliary tract diseases and surgeries(both P<0.001),benign disease(P=0.002),and the comorbidity chronic renal insufficiency(P=0.007)affected the positive rates of the bile samples.CONCLUSION Gram-negative bacteria were the most commonly isolated biliary bacteria.We determined the major factors associated with positive detection rates.Microbiological analysis of bile samples allowed accurate antibiotic treatments.
基金Supported by National Natural Science Foundation of China(Grant No.51805131)Postdoctoral Research Foundation of China(Grant No.2018M640580)Fundamental Research Funds for the Central Universities(CN)Fundamental Research Funds for the Central Universities of China(Grant No.JZ2018HGBZ0155).
文摘There is a consensus in the aerospace field that the development of reusable liquid rockets can effectively reduce the launch expense.The pursuit of a long service life and reutilization highly depends on the bearing components.However,the rolling element bearings(REBs)used in the existing rocket turbopumps present obvious and increasing limitations due to their mechanical contacting mode.For REBs,high rotational speed and long service life are two performance indexes that mutually restrict each other.To go beyond the DN value(the product of the bearing bore and rotational speed)limit of REBs,the major space powers have conducted substantial explorations on the use of new types of bearings to replace the REB.This review discusses,first,the crucial role of bearings in rocket turbopumps and the related structural improvements of REBs.Then,with the prospect of application to the next generation of reusable liquid rocket turbopumps,the bearing candidates investigated by major space powers are summarized comprehensively.These promising alternatives to REBs include fluid-film,foil,and magnetic bearings,together with the novel superconducting compound bearings recently proposed by our team.Our more than ten years of relevant research on fluid-film and magnetic bearings are also introduced.This review is meaningful for the development of long-life and highly reliable bearings to be used in future reusable rocket turbopumps.