55 research outputs found
Naja naja atra
Systemic lupus erythematosus (SLE) is an autoimmune disease and effective therapy for this pathology is currently unavailable. We previously reported that oral administration of Naja naja atra venom (NNAV) had anti-inflammatory and immune regulatory actions. We speculated that NNAV may have therapeutic effects in MRL/lpr SLE mice. Twelve-week-old MRL/lpr mice received oral administration of NNAV (20, 40, and 80 μg/kg) or Tripterygium wilfordii polyglycosidium (10 mg/kg) daily for 16 weeks. The effects of NNAV on SLE manifestations, including skin erythema, proteinuria, and anxiety-like behaviors, were assessed with visual inspection and Multistix 8 SG strips and open field test, respectively. The pathology of spleen and kidney was examined with H&E staining. The changes in autoimmune antibodies and cytokines were determined with ELISA kits. The results showed that NNAV protected against the manifestation of SLE, including skin erythema and proteinuria. In addition, although no apparent histological change was found in liver and heart in MRL/lpr SLE mice, NNAV reduced the levels of glutamate pyruvate transaminase and creatine kinase. Furthermore, NNAV increased serum C3 and reduced concentrations of circulating globulin, anti-dsDNA antibody, and inflammatory cytokines IL-6 and TNF-α. NNAV also reduced lymphadenopathy and renal injury. These results suggest that NNAV may have therapeutic values in the treatment of SLE by inhibiting autoimmune responses
X-ray line spectrometry in experiments with the aluminium Z-pinch
X-ray line spectrometry with temporal resolution was developed for registration of [He]- and [H]-like aluminium ions spectrum. It was chosen a scheme with scintillator converting X-ray spectrum into the visible image, which was transferred through the flexible optical fiber to the entrance slit of the streak camera. In Z-pinch experiment on the high current S-300 generator the aluminium line spectrum was registered with nanosecond time resolution. The simultaneous appearance of [He]- and [H]-like aluminium ions radiation was observed, that is the evidence of high electron temperature existence in the plasma for a long time before the main part of the load mass comes to the axis. The noticeably changing of radiating plasma parameters was found after the computer treatment of line spectra: the electron concentration is varied in five times ((3…14)×10^19 cm^-3), electron temperature in three times (0.3…1 keV), ion temperature in five times (20…100 keV), – during 50 ns. The great difference between the electron and ion temperature holds during all radiation time and demonstrates the ineffective energy transfer from the kinetic energy of ions to electron.Разработана методика для регистрации с временным разрешением рентгеновских линий [He]- и [H]-подобных ионов алюминия. Рентгеновский спектр преобразовывался с помощью сцинтиллятора в видимое изображение, которое переносилось гибким световодом на входную щель электронно-оптического преобразователя. Регистрация спектра проводилась с наносекундным разрешением в экспериментах с Z-пинчем на сильноточном генераторе С-300. Наблюдалось одновременное появление линий [He]- и [H]-подобных ионов алюминия, что является свидетельством наличия высокой электронной температуры в плазме задолго до момента прихода к оси основной массы Z-пинча. Компьютерная обработка спектров выявила значительные изменения параметров плазмы в процессе сжатия: концентрации в пять раз ((3…14)×10^19 см^-3), электронной температуры в три (0.3…1 кэВ), ионной температуры в пять раз (20…100 кэВ) – за 50 нс. Большой разрыв между ионной и электронной температурами демонстрирует неэффективность передачи энергии от ионов к электронам.Розроблено методику для реєстрації з часовим дозволом рентгенівських ліній [He]- і [H]-подібних іонів алюмінію. Рентгенівський спектр перетворювався за допомогою сцинтиллятора у видиме зображення, що переносилося гнучким світловодом на вхідну щілину електронно-оптичного перетворювача. Реєстрація спектра проводилася з наносекундним дозволом в експериментах з Z-пінчем на потужнострумовому генераторі С-300. Спостерігалася одночасна поява ліній [He]- і [H]-подібних іонів алюмінію, що є свідченням наявності високої електронної температури в плазмі задовго до моменту приходу до осі основної маси Z-пінча. Комп'ютерна обробка спектрів виявила значні зміни параметрів плазми в процесі стиску: концентрації в п'ять разів ((3...14)×10^19см^-3), електронної температури в три (0.3...1кеВ), іонної температури в п'ять разів (20...100 кеВ) – за 50 нс. Великий розрив між іонною й електронною температурами демонструє неефективність передачі енергії від іонів до електронів
The cause analysis of benign uretero-ileal anastomotic stricture after radical cystectomy and urinary diversion
BackgroundBenign uretero-ileal anastomotic stricture (UIAS) is a major complication following radical cystectomy (RC) and ileal orthotopic bladder substitution, and it can occur in combination with other complications. But risk factors for patients with UIAS have not been well described.Material and methodsWe retrospectively reviewed 198 patients treated with RC for bladder cancer from 2014 to 2019 at the Zhejiang Provincial People’s Hospital. Patient demographic and clinical variables were examined to determine the risk factors associated with UIAS by univariate and multivariate logistic regression analysis.ResultsA total of 180 patients into the group standards and in all 360 uretero-ileal anastomoses. Among the above cases, 22 patients developed UIAS, including 10 cases of left UIAS, nine cases of right UIAS, and three cases of bilateral UIAS. There was no difference in demographic, operative, or perioperative variables between patients with and without UIAS. In a multivariate analysis, after adjusting for gender, age, surgical methods, and underlying diseases, intraoperative or postoperative blood transfusion (HR = 0.144, P <0.01), postoperative urinary tract infection (HR = 3.624, P <0.01), and extracorporeal bladder anastomosis (HR = 3.395, P = 0.02) significantly increased the risk of UIAS.ConclusionsIn our experience, intraoperative or postoperative blood transfusion, postoperative urinary tract infection, and extracorporeal neobladder anastomoses increased the risk of UIAS after radical cystectomy and ileal orthotopic bladder substitution surgery. Further studies with larger samples are necessary to validate this result
Intrinsically Tuning the Electromechanical Properties of Elastomeric Dielectrics:A Chemistry Perspective
Dielectric elastomers have the capability to be used as transducers for actuation and energy harvesting applications due to their excellent combination of large strain capability (100–400%), rapid response (10−3 s), high energy density (10–150 kJ m−3), low noise, and lightweight nature. However, the dielectric properties of non‐polar elastomers such as dielectric permittivity ε r , breakdown strength E b , and dielectric loss ε ″, need to be enhanced for real world applications. The introduction of polar groups or structures into dielectric elastomers through covalently bonding is an attractive approach to ‘intrinsically’ induce a permanent polarity to the elastomers, and can eliminate the poor post‐processing issues and breakdown strength of extrinsically modified materials, which have often been prepared by incorporation of fillers. This review discusses the chemical methods for modification of dielectric elastomers, such as hydrosilylation, thiol‐ene click chemistry, azide click chemistry, and atom transfer radical polymerization. The effects of the type and concentration of polar groups on the dielectric and mechanical properties of the elastomers and their performance in actuation and harvesting systems are discussed. State‐of‐the‐art developments and perspectives of modified dielectric elastomers for deformable energy generators and transducers are provided
The prosurvival role of autophagy in Resveratrol-induced cytotoxicity in human U251 glioma cells
Abstract Background Previous study reported that resveratrol has anti-tumor activity. In this study, we investigated the involvement of autophagy in the resveratrol-induced apoptotic death of human U251 glioma cells. Methods The growth inhibition of U251 cells induced by resveratrol was assessed with methyl thiazolyl tetrazolium (MTT). The activation of autophagy and proapoptotic effect were characterized by monodansylcadaverine labeling and Hoechst stain, respectively. Mitochondrialtransmembrane potential (ΔΨm) was measured as a function of drug treatment using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1). The role of autophagy and apoptosis in the resveratrol-induced death of U251 cells was assessed using autophagic and caspase inhibitors. Immunofluorescence, flow cytometry, and Western blot analysis were used to study the apoptotic and autophagic mechanisms. Results Methyl thiazolyl tetrazolium (MTT) assays indicated that resveratrol decreased the viability of U251 cells in a dose- and time-dependent manner. Flow cytometry analysis indicated that resveratrol increased cell population at sub-G1 phase, an index of apoptosis. Furthermore, resveratrol-induced cell death was associated with a collapse of the mitochondrial membrane potential. The pan-caspase inhibitor Z-VAD-fmk suppressed resveratrol-induced U251 cell death. Resveratrol stimulated autophagy was evidenced by punctuate monodansylcadaverine(MDC) staining and microtubule-associated protein light chain 3 (LC3) immunoreactivty. Resveratrol also increased protein levels of beclin 1 and membrane form LC3 (LC3-II). Autophagy inhibitors 3-methylademine (3-MA) and bafilomycin A1 sensitized the cytotoxicity of resveratrol. Conclusion Together, these findings indicate that resveratrol induces autophagy in human U251 glioma cells and autophagy suppressed resveratrol-induced apoptosis. This study thus suggests that autophagy inhibitors can increase the cytotoxicity of resveratrol to glioma cells.</p
Over-expression of NAD kinase in Corynebacterium crenatum and its Impact on L-Arginine Biosynthesis
Purpose: To improve the biosynthesis of L-arginine by overexpressing
homologous NAD kinase (ppnk) in Corynebacterium crenatum SYPA5-5 and
to study its impact in presence of high (HOS) and low oxygen supply
(LOS). Methods: A recombinant plasmid (pJC1-tac-ppnK) harboring
homologous NAD kinase (ppnk) was constructed in a shuttle vector pJC1
and transferred in L-arginine producing strain Corynebacterium crenatum
SYPA5-5. Furthermore, fermentation was performed by shake flask method
with consecutive determination of cell growth and glucose
concentration. NAD+ kinase activity was studied by stop method and
NADP(H) concentrations were determined by spectrophotometric enzymatic
cycling method. To check the biosynthesis of amino acids, HPLC method
was used to determine extracellular amino acid concentrations. Results:
In HOS condition, NAD+ kinase activity increased by 116 %, while
intracellular concentrations of NADP+ and NADPH increased by 7.3 and
36.8 %, respectively. Whereas, in LOS condition , NAD+ kinase activity
increased 49 % , with intracellular 14.67 and 15 % increases in NADP+
and NADPH respectively. More importantly, recombinant strain could
produce 26.47 and 11.36 g/L L-arginine in HOS and LOS respectively,
which is higher than control strain value of 24.29 and 7.58 g/L
respectively. Conclusion: These results suggest that altering the
concentration of co-enzymes by NAD kinase in Corynebacterium crenatum
is an effective way to increase NADP+ with concurrent production of
NADPH for further enhanced L-arginine biosynthesis in Corynebacterium
crenatum in both conditions of high and low oxygen supply
Image classification using HTM cortical learning algorithms
Recently the improved bag of features (BoF) model with locality-constrained linear coding (LLC) and spatial pyramid matching (SPM) achieved state-of-the-art performance in image classification. However, only adopting SPM to exploit spatial information is not enough for satisfactory performance. In this paper, we use hierarchical temporal memory (HTM) cortical learning algorithms to extend this LLC & SPM based model. HTM regions consist of HTM cells are constructed to spatial pool the LLC codes. Each cell receives a subset of LLC codes, and adjacent subsets are overlapped so that more spatial information can be captured. Additionally, HTM cortical learning algorithms have two processes: learning phase which make the HTM cell only receive most frequent LLC codes, and inhibition phase which ensure that the output of HTM regions is sparse. The experimental results on Caltech 101 and UIUC-Sport dataset show the improvement on the original LLC & SPM based model
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