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1.
Eur Rev Med Pharmacol Sci ; 25(7): 2852-2857, 2021 04.
Article in English | MEDLINE | ID: mdl-33877650

ABSTRACT

OBJECTIVE: This study aims to evaluate the clinical application value of flash spiral mode of high-pitch dual source CT in carotid, cardiac and cerebral vessels combined one-stop imaging. PATIENTS AND METHODS: A total of 100 consecutive patients were given carotid, cardiac and cerebral vessels combined one-stop imaging at flash spiral mode of high-pitch dual source CT. 27 patients received DSA examination of carotid and cerebral vessels, and 38 patients received digital subtraction angiography (DSA) examination of the coronary artery at the same time. Carotid, cardiac and cerebral vessels combined one-stop imaging was compared with "golden standard", DSA image. RESULTS: The overall satisfaction rate of coronary arteries, extracranial segment of the carotid artery (CA-E), intracranial segment of the carotid artery (CA-I), and cerebral vessels (anterior, middle, and posterior cerebral artery) were 93%, 99%, 95% and 97% respectively, and the positive rate of hemadostenosis was consistent with DSA. The kappa value indicating consistency of cerebral, carotid and coronary artery vessels was 0.78382, 0.80654, 0.82398, respectively. CONCLUSIONS: The method of carotid, cardiac and cerebral vessels combined one-stop imaging by flash spiral mode of high-pitch dual source CT can provide high image quality. It comprehensively evaluates stenosis of carotid, cardiac and cerebral vessels, which is of great importance for early intervention in harmful events of the cardia and cerebrovascular disorder.


Subject(s)
Angiography, Digital Subtraction , Carotid Arteries/diagnostic imaging , Coronary Vessels/diagnostic imaging , Heart/diagnostic imaging , Tomography, X-Ray Computed , Humans
2.
Zhonghua Gan Zang Bing Za Zhi ; 28(8): 679-685, 2020 Aug 20.
Article in Chinese | MEDLINE | ID: mdl-32911907

ABSTRACT

Objective: To retrospectively analyze the risk factors for the development of liver cancer in patients with hepatitis B-related liver cirrhosis (LC) treated and fully managed with long-term nucleos(t)ide analogues (NAs). Methods: The study subjects were derived from the follow-up cohort of chronic hepatitis B and liver cirrhosis who received antiviral therapy in the Department of Infectious Diseases of the First Affiliated Hospital of Guangxi Medical University from February 2004 to September 2019. LC patients who met the inclusion criteria were enrolled. The life-table method was used to calculate the incidence of liver cancer. Multivariable Cox regression model was used to analyze the risk factors that may affect the development of liver cancer in patients with LC. A subgroup analysis was conducted in liver cirrhotic patients who developed liver cancer to evaluate the effectiveness of antiviral treatment compliance. The (2) test was used for rate comparison. Results: The median follow-up time of 198 LC cases treated with NAs was 6.0 years (1.0-15.3 years). By the end of the visit: (1) 16.2% (32/198) of LC patients had developed liver cancer, and the cumulative incidence of liver cancer in 1, 3, 5, 7, and 9 years were 0, 8.9%, 14.3%, 18.6%, and 23.4%, respectively, with an average annual incidence of 3.1%. Among the 32 cases with liver cancer, 68.7% had developed small liver cancer (22/32). (2) Univariate Cox model analysis showed that the development of liver cancer was related to four factors, i.e., the presence or absence of LC nodules, whether the baseline was first-line medication, the family history of liver cancer, and patient compliance. The results of multivariate Cox model analysis showed that poor patient compliance and baseline non-first-line medication were risk factors for liver cancer. (3) The results of log-rank test subgroup analysis showed that the 5-year cumulative incidence of liver cancer in patients with hardened nodules was significantly higher than that of patients without hardened nodules (21.7% vs. 11.5%, P = 0.029). The 5-year cumulative incidence of liver cancer in patients with non-first-line drugs was significantly higher than that of patients with first-line drugs (22.0% vs.8.2%, P = 0.003). The 5-year cumulative incidence of liver cancer in patients with poor compliance was significantly higher than that of patients with good compliance (21.3% vs. 12.7%, P = 0.014). The 5-year cumulative incidence of liver cancer in patients with a family history of liver cancer was significantly higher than that of patients without a family history of liver cancer (22.3% vs. 8.1%, P = 0.006). (4) Compared with patients with poor compliance, patients with good compliance had higher HBV DNA negative serconversion rate (98.7% vs. 87.8%, P = 0.005), and a lower virological breakthrough rate (12.1% vs. 29.3%, P = 0.007). Conclusion: The long-term NAs antiviral therapy can reduce the risk of liver cancer, but it cannot completely prevent the development of liver cancer, especially in patients with a family history of liver cancer and baseline hardened nodules (high risk of liver cancer). Furthermore, the complete management can improve patient compliance, ensure the efficacy of antiviral therapy, and reduce the risk of liver cancer development, so to achieve secondary prevention of liver cancer, i.e., early detection, diagnosis and treatment.


Subject(s)
Antiviral Agents , Carcinoma, Hepatocellular , Hepatitis B, Chronic , Hepatitis B , Liver Neoplasms , Antiviral Agents/therapeutic use , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/epidemiology , Carcinoma, Hepatocellular/virology , China/epidemiology , Hepatitis B/complications , Hepatitis B/drug therapy , Hepatitis B virus , Hepatitis B, Chronic/complications , Hepatitis B, Chronic/drug therapy , Humans , Lamivudine/therapeutic use , Liver Cirrhosis/drug therapy , Liver Cirrhosis/epidemiology , Liver Neoplasms/drug therapy , Liver Neoplasms/epidemiology , Liver Neoplasms/virology , Retrospective Studies , Risk Factors
3.
Zhonghua Gan Zang Bing Za Zhi ; 28(12): 1013-1017, 2020 Dec 20.
Article in Chinese | MEDLINE | ID: mdl-34865348

ABSTRACT

Objective: To retrospectively analyze the serological, virological, biochemical, liver histological status and clinical outcomes in HBeAg-negative chronic hepatitis B (CHB) patients with low HBV viral load, and to explore the necessity of antiviral therapy for these patients. Methods: A total of 99 HBeAg-negative CHB patients with HBV DNA level < 4 lg copies/ml who performed liver biopsy at the baseline were enrolled from the follow-up cohort. Among them, 23 cases received the second liver biopsy during follow-up. The relationships among the degree of inflammation and fibrosis of liver tissues, the status of HBsAg and HBcAg, age, gender, family history, HBV DNA load, serological markers and other indicators were analyzed. The pathological differences between two liver biopsy examinations were compared. The effect of nucleos(t)ide analogues (NAs) treatment on patient's clinical outcomes were analyzed. For multivariate analysis, a binary logistic regression model was performed. Log-rank test was used to compare the cumulative incidence of hepatocellular carcinoma (HCC) in NAs-treated and non-NA streated patients. Results: Baseline liver histology status showed that 58.6% (58/99) patients had obvious liver tissue damage in their baseline liver tissue pathology (G≥2 and /or S≥2). Univariate logistic regression analysis showed that a liver cirrhosis (LC) family history, a HBsAg-positive family history, baseline alanine aminotransferase and aspartate aminotransferase levels were positively correlated factors for liver tissue damage. Multivariate logistic regression analysis showed that a LC family history was the main risk factor for liver tissue damage. Twenty-three cases had received a second liver biopsy after an interval of 4.5 years. In 10 untreated cases, the second liver biopsy results showed the rate of obvious liver tissue damage (G≥2 and/ or S≥2) increased from 50.0% to 90.0%. In the other 13 cases who received NAs treatment, the second liver biopsy showed improvement in liver histology, and the rate of obvious liver tissue damage decreased from 61.5% to 46.2%. The 5-year HCC cumulative incidence in non-NAs-treated patients was significantly higher than that of in NAs-treated patients (17.7% vs. 3.8%, P = 0.046). Conclusion: For most HBeAg-negative CHB patients with low viral load, liver tissue pathology result suggests that it meets the indications for antiviral therapy, especially in patients with a LC familial history. Without antiviral therapy, liver tissue damage for these patients will progressively worse with the high incidence of HCC. Therefore, it is suggested that antiviral therapy should be started as soon as possible for the HBeAg-negative CHB patients with low viral load regardless of the alanine aminotransferase level, especially in patients over 30 years-old with a LC or HCC family history.


Subject(s)
Carcinoma, Hepatocellular , Hepatitis B, Chronic , Liver Neoplasms , Adult , DNA, Viral , Hepatitis B e Antigens , Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , Humans , Retrospective Studies , Viral Load
4.
Poult Sci ; 97(7): 2258-2266, 2018 Jul 01.
Article in English | MEDLINE | ID: mdl-29688456

ABSTRACT

In mammals, fibroblast growth factor 23 (FGF23) regulates phosphate homeostasis in kidney by binding α-Klotho, a coreceptor of FGF23. FGF23 mRNA is highly expressed in bone and slightly expressed in liver, and is regulated by dietary phosphorus. Little is known about distribution and regulation of FGF23 mRNA in avian lineage. The expression of FGF23 and its coreceptor α-Klotho in chicken and embryo were investigated by real-time quantitative PCR. The effect of dietary phosphorus on FGF23 expression was measured. 36 laying hens at 25 wk were randomly assigned to three dietary available phosphorus (AP) treatments for 11 days: 0.15% AP (LP), 0.40% AP (MP), and 0.80% AP (HP). We first cloned the full coding sequence of FGF23 by the reverse transcription PCR from chicken liver and calvaria. Bioinformatics analysis indicated that the deduced amino acid sequence was 57-87% identical to FGF23 of other species. In adult chicken FGF23 mRNA was expressed at unexpected higher level in liver than other tissues evaluated, including calvaria, femur, tibia, medullary bone, brain, spleen, duodenum, jejunum, ileum, heart and kidney (P < 0.0001), and α-Klotho was expressed at highest level in kidney. However, in 18-d chicken embryos, FGF23 mRNA level was much higher in tibia than in liver, heart and jejunum (P < 0.0001). Chickens at 2, 25, 50 and 80 wk had higher FGF23 expression in liver than 18-d chicken embryos, whereas chickens at 25 wk had lower FGF23 expression in tibia than 18-d chicken embryos and 2-wk-old chickens. HP diets significantly increased serum inorganic phosphorus level (P < 0.001) and FGF23 expression (P < 0.05) in bone tissue compared with LP diets, however, FGF23 mRNA abundance in liver was not changed significantly (P > 0.05) by dietary phosphorus treatments. In conclusion, FGF23 mRNA expression pattern in chicken was clearly different from that in mammals and dietary phosphorus regulated the expression of FGF23 in a tissue-specific way.


Subject(s)
Avian Proteins/genetics , Chickens/genetics , Fibroblast Growth Factors/genetics , Gene Expression Regulation , Phosphorus, Dietary/metabolism , Transcriptome , Amino Acid Sequence , Animals , Avian Proteins/chemistry , Avian Proteins/metabolism , Base Sequence , Bone and Bones/metabolism , Chickens/metabolism , Female , Fibroblast Growth Factor-23 , Fibroblast Growth Factors/metabolism , Gene Expression Profiling/veterinary , Liver/metabolism , Mice , RNA, Messenger/genetics , RNA, Messenger/metabolism , Random Allocation , Sequence Alignment/veterinary
6.
Clin Transl Oncol ; 18(6): 576-81, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26527033

ABSTRACT

BACKGROUND: The strategy of dual inhibiting epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) pathways has been extensively investigated in advanced non-small-cell lung cancer (NSCLC), but the benefit-to-risk ratio of dual-targeted regimen versus EGFR-tyrosine kinase inhibitors (TKIs) alone is still unclear. We thus perform this meta-analysis to assess the efficacy and safety of this regimen versus EGFR-TKIs alone in those patients. METHODS: Databases from PubMed, Web of Science and the Cochrane Library up to March 31, 2015 were searched to identify relevant studies. Eligible studies included prospective randomized controlled trials (RCTs) evaluating dual inhibiting EGFR and VEGF pathways versus EGFR-TKIs alone in advanced NSCLC. The endpoints were overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and grade 3 or 4 adverse events. Statistical analyses were conducted by using either random effects or fixed effect models according to the heterogeneity of included studies. RESULTS: A total of 1918 patients with advanced NSCLC from 4 RCTs were identified for the analysis. The pooled results demonstrated that dual inhibiting EGFR and VEGF pathways significantly improved the PFS (HR 0.71, 95 % CI 0.58-0.86, p < 0.001) and ORR (OR 1.54, 95 % CI 1.14-2.08, p = 0.005) in unselected NSCLC when compared to EGFR-TKIs alone, but it did not translate into OS benefit (HR 0.94, 95 % CI 0.84-1.05, p = 0.24). No evidence of publication bias was observed. CONCLUSIONS: Our study suggests that dual inhibition of EGFR and VEGF pathways significantly improves PFS and ORR, but it does not translate into survival benefit in unselected NSCLC patients. Prospective clinical trials investigating the role of this regimen in EGFR mutation-positive NSCLC are still warranted.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , ErbB Receptors/antagonists & inhibitors , Lung Neoplasms/drug therapy , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Humans , Protein Kinase Inhibitors/therapeutic use , Randomized Controlled Trials as Topic
7.
Anim Genet ; 46(3): 272-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25917299

ABSTRACT

Toll-like receptors (TLRs), an important family of pattern-recognition receptors, and antimicrobial peptides (AMPs) contribute to the first line of innate protection of mammals against microbes. To compare characteristics of innate immunity between Tibetan and Yorkshire pigs, we investigated the mRNA abundance of TLR genes (TLR1-TLR9) and two AMP-encoding genes (PBD-1 and PR-39) in thymus, spleen, blood, palatine tonsils, and mesenteric and pulmonary hilar lymph nodes of the two breeds at ages of 6, 12 and 24 weeks using quantitative real-time PCR. Results showed that all mRNAs were detected in all tissues. Transcript levels of the major TLR genes of Tibetan pigs were significantly higher than those of Yorkshires in most tissues of the immune system, with a higher abundance of porcine (PBD-1) (beta-defensin-1) and PR-39 mRNA in lymphoid organs and tissues, especially blood, palatine tonsils, and mesenteric and pulmonary hilar lymph nodes. Our data suggest that Tibetan pigs have stronger innate immunity for triggering local and/or systemic immune responses to eliminate infections with pathogenic microorganisms.


Subject(s)
Antimicrobial Cationic Peptides/genetics , Swine/genetics , Toll-Like Receptors/genetics , Animals , Breeding , Female , Gene Expression , Immunity, Innate , Lymphoid Tissue/metabolism , Male , Swine/immunology
8.
J Nanosci Nanotechnol ; 12(2): 1094-8, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22629901

ABSTRACT

Nickel cobalt oxide alloy nanorings have been synthesized using a wet chemistry method. Standard characterization techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been used to characterize the nanorings. We, however, also examined the nanostructures in the helium ion microscope (HIM) and employed backscattered ion spectroscopy to determine thickness and composition of the nanostructure. The HIM provides complementary information of the nanostructures and the viability of using it as a tool for magnetic nanoparticle characterization was demonstrated by comparing the results from all three microscopes.

9.
Water Sci Technol ; 65(8): 1383-91, 2012.
Article in English | MEDLINE | ID: mdl-22466583

ABSTRACT

In this paper, a new kind of poly(acrylic acid) modified clay adsorbent, the poly(acrylic acid)/bentonite composite (PAA/HB) was prepared by in-situ polymerization, and utilized to remove lead(II) ions from solutions. The maximum adsorption of adsorbent is at pH 5 for metal ions, whereas the adsorption starts at pH 2. The effects of contact time (5-60 min), initial concentration of metal ions (200-1,000 mg/L) and adsorbent dosage (0.04-0.12 g/100 mL) have been reported in this article. The experimental data were investigated by means of kinetic and equilibrium adsorption isotherms. The kinetic data were analyzed by the pseudo-first-order and pseudo-second-order equation. The experimental data fitted the pseudo-second-order kinetic model very well. Langmuir and Freundlich isotherms were tried for the system to better understand the adsorption isotherm process. The maximal adsorption capacity of the lead(II) ions on the PAA/HB, as calculated from the Langmuir model, was 769.2 mg/g. The results in this study indicated that PAA/HB was an attractive candidate for removing lead(II) (99%).


Subject(s)
Acrylic Resins/chemistry , Bentonite/chemistry , Lead/isolation & purification , Water Pollutants, Chemical/isolation & purification , Adsorption , Hydrogen-Ion Concentration , Kinetics , Microscopy, Electron, Scanning , Polymerization , Spectroscopy, Fourier Transform Infrared , Thermodynamics , X-Ray Diffraction
10.
Water Sci Technol ; 61(11): 2749-57, 2010.
Article in English | MEDLINE | ID: mdl-20489247

ABSTRACT

A new kind of inorganic polymer flocculant, the solid composite polyferric sulfate (SPFS) was prepared using ferrous sulfate and Na-Bentonite. The obtained SPFS was characterized by FT-IR spectra, thermogravimetric analysis (TG), scanning electron microscope (SEM) and X-ray Diffraction (XRD). It showed that SPFS was a kind of composite inorganic polymer, which was the complex of PFS and Na-Bent, not only a simple mixture of raw materials. The synthetic mechanism and surface structure of SPFS were also discussed. Acting as a kind of environment-friendly flocculating agent, the solid composite polyferric sulfate (SPFS) was applied in pretreatment of potato starch industry wastewater, a typical wastewater containing high concentration organic compounds, which COD was above 6,000 mg/L. The results showed that the COD removal value reached 4,070 mg/L with COD removal rates being 46.6%. Based on these results, it is suggested that the SPFS can be attractive pretreatment agent for the starch industry wastewater.


Subject(s)
Ferric Compounds/chemistry , Flocculation , Organic Chemicals/chemistry , Waste Disposal, Fluid/methods , Industrial Waste , Microscopy, Acoustic , Spectroscopy, Fourier Transform Infrared
11.
Water Sci Technol ; 61(5): 1235-43, 2010.
Article in English | MEDLINE | ID: mdl-20220246

ABSTRACT

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb(2+)] = 500 mg L(-1), [XBent] = 2 g L(-1), pH = 5.0; oscillating 60 min under 200 rpm at 25 degrees C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions-XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.


Subject(s)
Bentonite/chemistry , Electrodes , Ions , Lead/isolation & purification , Xanthones/chemistry , Adsorption , Chelating Agents/pharmacology , Hydrogen-Ion Concentration , Lead/chemistry , Microscopy, Electron, Scanning/methods , Spectroscopy, Fourier Transform Infrared , Temperature , Thermogravimetry/methods , Time Factors , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , X-Ray Diffraction/methods
12.
J Mater Sci Mater Med ; 20(1): 223-8, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18758918

ABSTRACT

A dense titania film is fabricated in situ on NiTi shape memory alloy (SMA) by anodic oxidation in a Na(2)SO(4) electrolyte. The microstructure of the titania film and its influence on the biocompatibility of NiTi SMA are investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICPMS), hemolysis analysis, and platelet adhesion test. The results indicate that the titania film has a Ni-free zone near the surface and can effectively block the release of harmful Ni ions from the NiTi substrate in simulated body fluids. Moreover, the wettability, hemolysis resistance, and thromboresistance of the NiTi sample are improved by this anodic oxidation method.


Subject(s)
Biocompatible Materials/chemistry , Nickel/chemistry , Titanium/chemistry , Animals , Biocompatible Materials/toxicity , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/toxicity , Hemolysis/drug effects , In Vitro Techniques , Materials Testing , Microscopy, Electron, Scanning , Nickel/toxicity , Platelet Adhesiveness , Rabbits , Spectrum Analysis , Surface Properties , Titanium/toxicity , X-Rays
13.
Phys Rev Lett ; 100(1): 017205, 2008 Jan 11.
Article in English | MEDLINE | ID: mdl-18232814

ABSTRACT

The periodic shell structure and surface reconstruction of metallic FePt nanoparticles with icosahedral structure has been quantitatively studied by high-resolution transmission electron microscopy with focal series reconstruction with sub-angstrom resolution. The icosahedral FePt nanoparticles fabricated by the gas phase condensation technique in vacuum have been found to be surprisingly oxidation resistant and stable under electron beam irradiation. We find the lattice spacing of (111) planes in the surface region to be size dependent and to expand by as much as 9% with respect to the bulk value of Fe52Pt48. Controlled removal of the (111) surface layers in situ results in a similar outward relaxation of the new surface layer. This unusually large layerwise outward relaxation is discussed in terms of preferential Pt segregation to the surface forming a Pt enriched shell around a Fe-rich Fe/Pt core.

14.
Micron ; 35(6): 447-53, 2004.
Article in English | MEDLINE | ID: mdl-15120129

ABSTRACT

Large-scale micro/nanosized Ga(2)O(3) structures were synthesized via a simple vapor p9hase growth method. The morphology of the as-grown structures varied from aligned arrays of smooth nano/microscale wires to composite and complex microdendrites. We present evidence that the formation of the observed structure depends strongly on its position relative to the source materials (the concentration distribution) and on the growth temperature. A growth model is proposed, based on the vapor-solid (VS) mechanism, which can explain the observed morphologies.

15.
Micron ; 35(6): 475-80, 2004.
Article in English | MEDLINE | ID: mdl-15120133

ABSTRACT

Polycrystalline GaN thin films have been deposited epitaxially on a ZnO-buffered (111)-oriented Si substrate by molecular beam epitaxy. The microstructural and compositional characteristics of the films were studied by analytical transmission electron microscopy (TEM). A SiO(2) amorphous layer about 3.5 nm in thickness between the Si/ZnO interface has been identified by means of spatially resolved electron energy loss spectroscopy. Cross-sectional and plan-view TEM investigations reveal (GaN/ZnO/SiO(2)/Si) layers exhibiting definite a crystallographic relationship: [111](Si)//[111](ZnO)//[0001](GaN) along the epitaxy direction. GaN films are polycrystalline with nanoscale grains ( approximately 100 nm in size) grown along [0001] direction with about 20 degrees between the (1l00) planes of adjacent grains. A three-dimensional growth mode for the buffer layer and the film is proposed to explain the formation of the as-grown polycrystalline GaN films and the functionality of the buffer layer.

16.
Micron ; 35(6): 481-7, 2004.
Article in English | MEDLINE | ID: mdl-15120134

ABSTRACT

Unusual ZnO nanostructures have been successfully synthesized via selenium-controlled chemical vapor phase growth on Si (111) substrates at about 500 degrees C. The microstructure and chemical compositional characteristics of the ZnO nanomaterials have been systematically investigated by means of analytical transmission electron microscopy (TEM), including energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy. Most of the nanostructures have a belt-like morphology with typical widths of approximately 150 nm and lengths up to several micrometers. All the investigated materials are found to be stoichiometric ZnO with a hexagonal crystal structure. The growth directions for the nanobelts are found to be [1010] and [2110] respectively. Regular-triangle and needle-like heads with diameters only approximately 25-35 nm have been found in the straight nanobelts. High-resolution TEM images indicate that all the nanostructures are single crystals and free of defects. The growth mechanisms of such interesting and unique morphologies are briefly discussed.

17.
Biochem Biophys Res Commun ; 295(2): 475-81, 2002 Jul 12.
Article in English | MEDLINE | ID: mdl-12150974

ABSTRACT

Plasma osteocalcin, a marker of osteoblastic activity, is reduced in starvation, malnutrition, and anorexia nervosa, resulting in low bone turnover osteoporosis. Contradictory findings about the role of leptin as a link between nutritional status and bone physiology have been reported. We demonstrate that leptin-deficient ob/ob and leptin-resistant db/db male mice have increased plasma osteocalcin, and that in male ob/ob mice osteocalcin is not decreased by starvation, unlike control mice. Intraperitoneal leptin administration increased plasma osteocalcin in male ob/ob mice, and prevented its fall during 24h fasting and 5 days of food restriction in normal male mice. This effect may be mediated via actions on the hypothalamic-pituitary-testicular or -growth hormone axes, or a direct action on osteoblasts. These studies support the hypothesis that the fall in leptin during starvation and weight loss is responsible for the associated reduction in osteoblast activity, and suggest a role for leptin in regulating bone turnover.


Subject(s)
Leptin/pharmacology , Osteocalcin/blood , Starvation , Animals , Leptin/genetics , Leptin/physiology , Male , Mice , Mice, Inbred BALB C , Obesity/genetics , Pituitary Hormones/blood
18.
Micron ; 33(6): 575-80, 2002.
Article in English | MEDLINE | ID: mdl-12020705

ABSTRACT

A new Fe-Ni-Co-Nb-Ti-Si superalloy containing trace additions of selective rare earths and having good combination of very low thermal expansion coefficient, high-resistance to stress accelerated grain boundary oxygen embrittlement and fairly good notch-bar rupture strength has been successfully developed. The resistance to oxidation for long time exposure at high-temperatures and the stress rupture life has been improved significantly with trace yttrium addition. The microstructures of the alloys have been studied by means of analytical electron microscopy, chemical and X-ray analysis techniques. The results reveal that the trace yttrium segregates in the strengthening phase with platelet morphology, and helps in transforming A(3)B type epsilon phase into A(5)B type H. The morphology and crystal structures of the grain boundary phases also change with selective additions of rare earth elements. Compared with those in the conventional alloy, the platelet precipitates in the yttrium-containing alloy densely segregate within the grains and along the grain boundaries with smaller size. The segregation of the platelet precipitates within the grains is helpful in improving the strength of the alloy. In addition, its precipitation along the grain boundaries can improve the resistance to stress accelerated grain boundary oxidation and stress rupture property of the alloy and thereby contribute to its temperature stability.

19.
J Med Chem ; 44(22): 3692-9, 2001 Oct 25.
Article in English | MEDLINE | ID: mdl-11606134

ABSTRACT

Bengamide B, a novel sponge-derived marine natural product with broad spectrum antitumor activity, was not suitable for further preclinical development because of its difficult synthesis and very poor water solubility. Bengamide B produced a 31% T/C at its solubility-limited maximum intravenous dose of 33 micromol/kg in MDA-MB-435 breast carcinoma implanted subcutaneously as a xenograft in nude mice. Compound 8a, a bengamide B analogue with three structural changes (t-Bu alkene substituent, unsubstituted lactam nitrogen, and inverted lactam 5'-myristoyloxy group), was as potent as bengamide B in vitro and more efficacious than bengamide B in vivo. A series of ester-modified analogues based on 8a were synthesized and tested in vitro and in vivo (MDA-MB-435). The cyclohexyl- and phenethyl-substituted esters, 8c and 8g, respectively, had in vitro and in vivo activities similar to that of 8a and enhanced water solubility (ca. 1 mg/mL). Consequently, 8c and 8g were tested in the MDA-MB-435 xenograft model at 100 micromol/kg and produced 29% and 57% tumor regression, respectively.


Subject(s)
Antineoplastic Agents/chemical synthesis , Azepines/chemistry , Azepines/chemical synthesis , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Azepines/pharmacology , Drug Screening Assays, Antitumor , Humans , Mice , Mice, Nude , Solubility , Structure-Activity Relationship , Transplantation, Heterologous , Tumor Cells, Cultured
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