Study on the effect of aeration system on the mass transfer performance of supersaturated total dissolved gas.

ABSTRACTThe release of supersaturated total dissolved gas (STDG) from dams has been linked to the development of gas bubble disease, which can ultimately result in the death of fish. In order to minimize the impact of STDG on aquatic ecology, the effect of aeration on mass transfer at the air-liquid interface is taken into account. This paper selects four commonly used aerators to carry out indoor aeration tower experiments under different aeration conditions (aeration aperture, aeration water depth, and aeration volume), exploring aerators that can efficiently promote STDG release. The results indicated that the diaphragm aerator was found to have the greatest effect on STDG release, followed by corundum and spin mix aerator. In contrast, a pinhole aerator was found to have the least beneficial impact on STDG release. The increase in the release coefficient for the diaphragm aerator in comparison to the pinhole aerator is 32%. A prediction model for the aeration system was developed based on the mass transfer mechanism at the gas-liquid interface. The parameters in the model were determined using experimental data, which effectively improved the model's prediction accuracy. The findings of this study may serve as a reference point for the selection of the most suitable aerator in the actual engineering of STDG mitigation by aeration technology.

Secondhand smoke exposure can increase the risk of first ischemic stroke: A 10.7-year prospective cohort study in China.

INTRODUCTION: Passive smoking is considered a major public health issue in China. Prospective evidence regarding the link between secondhand smoke (SHS) and ischemic stroke in China is scarce. METHODS: The China Kadoorie Biobank (CKB) study in Liuzhou City recruited 50,174 participants during 2004-2008. Of these 30,456 never-smokers were included in our study. The median follow-up period was 10.7 years. The incidence of ischemic stroke was obtained through the China Disease Surveillance Points (DSP) system and the Health Insurance (HI) database. Cox proportional risk models were used to evaluate the association between SHS exposure and ischemic stroke. RESULTS: During 320,678 person-years of follow-up, there were 2059 patients with ischemic stroke observed and the incidence of ischemic stroke was 6.42 per thousand person-years. Participants exposed to SHS daily faced a 21 % higher risk of ischemic stroke (HR = 1.21, 95 %CI: 1.09-1.34) compared to those exposed to SHS less than once a week. Subgroup analyses revealed that daily SHS exposure was linked to heightened risk of ischemic stroke among women, non-employed, and non-weekly tea drinkers. CONCLUSIONS: Daily SHS exposure was associated with higher risks of ischemic stroke. Proactive tobacco control strategies are necessary to decrease the risk of ischemic stroke in never smokers.

Spicy food consumption reduces the risk of ischaemic stroke: a prospective study.

Previous studies revealed that consuming spicy food reduced mortality from CVD and lowered stroke risk. However, no studies reported the relationship between spicy food consumption, stroke types and dose­response. This study aimed to further explore the association between the frequency of spicy food intake and the risk of stroke in a large prospective cohort study. In this study, 50 174 participants aged 30­79 years were recruited. Spicy food consumption data were collected via a baseline survey questionnaire. Outcomes were incidence of any stroke, ischaemic stroke (IS) and haemorrhagic stroke (HS). Multivariable-adjusted Cox proportional hazard models estimated the association between the consumption of spicy food and incident stroke. Restricted cubic spline analysis was used to examine the dose­response relationship. During the median 10·7-year follow-up, 3967 strokes were recorded, including 3494 IS and 516 HS. Compared with those who never/rarely consumed spicy food, those who consumed spicy food monthly, 1­2 d/week and 3­5 d/week had hazard ratio (HR) of 0·914 (95 % CI 0·841, 0·995), 0·869 (95 % CI 0·758, 0·995) and 0·826 (95 % CI 0·714, 0·956) for overall stroke, respectively. For IS, the corresponding HR) were 0·909 (95 % CI 0·832, 0·994), 0·831 (95 % CI 0·718, 0·962) and 0·813 (95 % CI 0·696, 0·951), respectively. This protective effect showed a U-shaped dose­response relationship. For obese participants, consuming spicy food ≥ 3 d/week was negatively associated with the risk of IS. We found the consumption of spicy food was negatively associated with the risk of IS and had a U-shaped dose­response relationship with risk of IS. Individuals who consumed spicy food 3­5 d/week had a significantly lowest risk of IS.

Extreme detectable vibration frequency limited by rolling shutter camera imaging of laser speckles.

The row scanning mechanism of a rolling shutter camera can be used to infer high-frequency information from a low-frame-rate video. Combining the high intensity of laser speckle and high row-sampling rate of a rolling shutter, extreme detectable vibration frequency limited by rolling shutter camera imaging is experimentally demonstrated. Using a commercially available industrial camera at a frame rate of 70 fps, a vibration signal with a frequency of 14.285 kHz is extracted that corresponds to an inter-row sampling period of 35 µs and a sampling frequency of 28.57 kHz. Connected component and centroid alignment algorithms are used to extract the inter-row vibration displacement. The parameters that limit the highest and lowest detectable frequencies are discussed.

Tuber flours improve intestinal health and modulate gut microbiota composition.

The different health effects between starch and whole flour from tubers are rarely studied. Here, we investigated the effects of cassava flour (CF), cassava starch (CS), potato flour (PF), and potato starch (PS) on gut health and gut microbiota of normal rats. Feed analysis showed that CF and PF diet provided significantly more slowly digestible and resistant starch, less rapidly digestible starch. Compared with rats fed with PS and CS diets, rats fed with PF and CF diets gained less body weight and have tighter intestinal barrier. Butyric acid contents were increased by tuber flours. CF and PF selectively promoted the relative abundance of Akkermansia and Eubacterium ruminantium in cecal and colonic content. In conclusion, tuber flour has intestinal protection, body weight control, and gut microbiota improving ability compared with starch. The different composition of starch might be the basis for these effects.

SPECT Imaging of Treatment-Related Tumor Necrosis Using Technetium-99m-Labeled Rhein.

PURPOSE: Noninvasive imaging of treatment-induced necrosis is important to distinguish early responders from patients resistant to the treatment plan, enabling the tailored-made therapeutic intervention. The purpose of this study was to explore the feasibility of [99mTc]EDDA-HYNIC-2C-rhein for early assessment of tumor response to treatment. PROCEDURES: In vitro necrosis avidity of [99mTc]EDDA-HYNIC-2C-rhein was evaluated in human lung cancer A549 cells treated with hyperthermia. Single photon emission-computed tomography/X-ray-computed tomography (SPECT/CT) imaging was performed in rats bearing subcutaneous W256 tumor treated with combretastatin A-4 disodium phosphate (CA4P) and rats bearing orthotopic liver W256 tumor treated with a single microwave ablation. All rats were euthanized immediately after the imaging session for biodistribution and histology studies. The mechanism of necrosis avidity for the tracer was further explored by in vivo blocking experiment and in vitro histochemistry and fluorescence staining. RESULTS: The uptake of [99mTc]EDDA-HYNIC-2C-rhein in necrotic cells was significantly higher than that in viable cells (p < 0.05). SPECT/CT imaging showed that an obvious "hot spot" was observed in the CA4P-treated tumor while not in the control tumor at 5 h after tracer injection. Ex vivo γ-counting revealed that the uptake of [99mTc]EDDA-HYNIC-2C-rhein in tumor was increased 3.5-fold in rats treated with CA4P compared with rats treated with vehicle. Autoradiography and corresponding H&E staining suggested that the higher overall radiotracer uptake in the treated tumors was attributed to the increased necrosis. Blocking with unlabeled HYNIC-2C-rhein demonstrated the specific binding of the radiotracer to necrotic tissues. The perfect match of autoradiograph and histochemistry staining and PI fluorescence staining revealed that necrosis avidity of the tracer may be attributable to intercalation with exposed DNA in necrotic tissues. CONCLUSION: [99mTc]EDDA-HYNIC-2C-rhein can image necrosis induced by anticancer therapy and holds potential for early assessment of treatment response.

First Evaluation of Radioiodinated Flavonoids as Necrosis-Avid Agents and Application in Early Assessment of Tumor Necrosis.

A rapid and accurate identification of necrotic tissues is of great importance to define disease severity, predict prognosis, and monitor responses to therapies. To seek necrosis-avid agents with clinically translational potential, we first evaluated the necrosis avidity of flavonoids in rodent models of muscular, myocardial, and tumoral necrosis. In this study, the necrosis avidity of eight radioiodinated 5,7-dihydroxyflavones was tested by ex vivo gamma counting, histochemical staining, and autoradiography in mouse models of ethanol-induced muscular necrosis. The necrosis avidity of a lead tracer, 131I-5, was further assessed in rat models of myocardial infarction and reperfusion. Therapy response was evaluated by 131I-5 single photon emission computed tomography/computed tomography imaging 24 h after combretastatin A-4 disodium phosphate (CA4P) therapy on rats bearing W256 breast carcinomas. The necrosis avidity mechanism for the tracers was studied by in vitro DNA binding experiments of 12 5,7-dihydroxyflavones and in vivo blocking experiments of 131I-5. In the results, all 131I-5,7-dihydroxyflavones showed intense uptake to necrotic muscles, and 131I-5 emerged as the most potential tracer among them. 131I-5 obtained a necrotic-viable myocardium ratio of 5.0 ± 0.9 in post-mortem biodistribution on reperfused myocardial infarction models and achieved necrosis imaging on CA4P-treated W256 tumors 4 h after tracer injection. DNA binding studies suggested that necrosis avidity was related to DNA binding to a certain extent. The uptake of 131I-5 in necrotic muscle was markedly blocked by excessive ethidium bromide and cold 5 with a 51.95% and 64.29% decline at 1 h after coinjection, respectively. In conclusion, flavonoids are necrosis-avid agents. Furthermore, 131I-5 can serve as a promising necrosis-avid diagnostic tracer for the rapid imaging of necrotic tissues, supporting the further molecular design of radiotracer based on 5.

Chemical UPLC-ESI-MS/MS profiling of aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Aconitum carmichaelii Debx. Root extract.

In this paper, an ultra high performance liquid chromatography tandem mass spectrometric (UPLC-ESI-MS/MS) method in positive ion mode was established to systematically identify and to compare the major aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Fuzi extract. A total twenty-nine components including twenty-five C19-diterpenoid alkaloids and four C20-diterpenoid alkaloids were identified in Fuzi extract. Thirteen of the parent components and five metabolites were detected in rat plasma and sixteen parent compounds and six metabolites in urine. These parent components found in rat plasma and urine were mainly C19-diterpenoid alkaloids. All of the metabolites in vivo were demethylated metabolites (phase I metabolites), which suggested that demethylation was the major metabolic pathway of aconitum alkaloids in vivo. A comparison of the parent components in rat plasma and urine revealed that 3-deoxyacontine was found in plasma but not in urine, while kalacolidine, senbusine and 16-ß-hydroxycardiopetaline existed in urine but not in plasma, which indicated that most alkaloids components were disposed and excreted in prototype form. This research provides some important information for further metabolic investigations of Fuzi in vivo.

[Metabonomic study on the anti-liver injury effect of Si-Ni-San on rats by using UPLC-MS/MS].

A UPLC-MS/MS method based on metabonomic skills was developed to study the serum metabolic changes of rats after acute liver injury induced by CCl4 and to evaluate the action mechanism of Si-Ni-San. The integrated data were exported for principal components analysis (PCA) by using SIMCA-P software, in order to find the potential biomarkers. It showed that clear separation of healthy control group, model group, silymarin group, Si-Ni-San group was achieved by using the PCA method. Nine significantly changed metabolites were identified as potential biomarkers of acute liver injury. Compared with the health control group, the model group rats showed higher levels of phenylalanine, tryptophan and GCDCA together with lower levels of LPC 16 : 0, LPC 18 : 0, LPC 18 : 1, LPC 16 : 1, LPC 20 : 4 and LPC 22 : 6. These changes of serum metabolites suggested that the disorders of amino acid metabolism, lipid metabolism, bile acid biosynthesis and anti-oxidative damage were related to acute liver injury induced by CCl4. Si-Ni-San might have the anti-liver injury effect on all these four metabolic pathways.

[Expression of DNA-dependent protein kinase catalytic subunit in adult acute leukemia and its significance].

This study was aimed to explore the expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in adult acute leukemia and its correlation with clinical characteristics, karyotype and prognosis. Indirect immunofluorescent cytometry was used to detect the expression of DNA-PKcs in bone marrow mononuclear cells of 105 patients with acute leukemia before chemotherapy and 41 of them after 2 cycles of chemotherapy. Cytogenetic data were obtained from 26 of them by R band karyotypic analysis. The results showed that the expression of DNA-PKcs was correlated with higher WBC count level in peripheral blood (p < 0.05), but was not obviously associated with median age, gender, percentage of bone marrow blasts, clinical classification, median hemoglobin level and median platelet count (p > 0.05). The middle and strong positive expression of DNA-Pkcs in non-remission group was significantly higher than that in remission group (p < 0.05). The positive rate of DNA-PKcs in abnormal chromosome group was significantly higher than that in chromosome normal group (p < 0.05). It is concluded that the DNA-PKcs expression level is closely related with the increased WBC count, and the expression of DNA-PKcs is correlated also with karyotype and clinical prognosis in adult acute leukemia.

[Screening and structure analysis of nucleic acid aptamers binding to surface of CD33(+)/CD34(+) cells from patients with acute myeloid leukemia subtype M2].

A little is known about the specific marker on the surface of acute leukemia cells, leading to the lack of the specific diagnosis method for acute leukemia. Therefore, in this study, cell-systematic evolution of ligands by exponential enrichment (cSELEX) was performed to screen the aptamers binding to CD33(+)/CD34(+) cells from the patients with acute myeloblastic leukemia (AML) of M(2) subtype (AML-M2) so as to provide the basis for finding the specific marker on the surface of AML-M(2) CD33(+)/CD34(+) cells. Firstly, AML-M2 CD33(+)/CD34(+) cells were sorted and used as targeted cells, and normal CD33(+)/CD34(+)cells were used as counter-targeted cells; the aptamers binding to CD33(+)/CD34(+) cells from patients with AML-M2 were screened from the single strand deoxyribonucleic acid (ssDNA) library by cSELEX. Subsequently, each aptamer structure was analyzed after cloning and sequencing. The results indicated that after 13 round of screenings, the enrichment of aptamers in the ssDNA library was ranged from 0.7% to 52.9%, and reached steady state at 13th round screening. Sequence analysis for 30 aptamers showed that most of the aptamers born one of the three conserved sequences of CCCCT, CTCTC, and CTCAC. Secondary structure analysis indicated that three different secondary structures existed in these aptamers. It is concluded that the aptamers binding to the AML-M(2) CD33(+)/CD34(+) cells are successfully screened, which lay the basis for further looking for the specific marker on the surface of AML-M2 CD33(+)/CD34(+) cells, and the molecular diagnosis of the AML-M2 leukemia.