270 research outputs found

    Environmentally Friendly Pervious Concrete for Treating Deicer-Laden Stormwater: Phase I

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    A graphene oxide-modified pervious concrete was developed by using low-reactivity, high-calcium fly ash as sole binder and chemical activators and other admixtures. The density, void ratio, mechanical strength, infiltration rate, Young’s modulus, freeze-deicer salt scaling, and degradation resistance of this pervious concrete were measured against three control groups. The test results indicate that graphene oxide modified fly ash pervious concrete is comparable to Portland cement pervious concrete. While the addition of 0.03% graphene oxide (by weight of fly ash) noticeably increased the compressive strength, split tensile strength, Young’s modulus, freeze-deicer salt scaling, and degradation resistance of fly ash pervious concrete, it reduced the void ratio and infiltration rate. The fly ash pervious concrete also showed unfavorable high initial loss during the freeze-deicer salt scaling test, which may be attributed to the low hydration degree of fly ash at early age. It is recommended that durability tests for fly ash concrete be performed at a later age

    Environmentally Friendly Pervious Concrete for Treating Deicer-Laden Stormwater: Phase II

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    In Phase I of this project, graphene oxide (GO)-modified pervious concrete was developed using coal fly ash as the sole binder. The primary objectives of Phase II of this project were (1) to evaluate the stormwater infiltration capacity of GO-modified fly ash pervious concrete; (2) to evaluate the durability performance of GO-modified fly ash pervious concrete using freeze/thaw and salt resistance testing methods; and (3) to use advanced analytical tools to fully characterize the GO-modified fly ash binder. Test results indicate different degrees of reduction in concentrations of possible pollutants in stormwater—copper, zinc, sulphate, chloride, ammonia, nitrate, and total phosphate. The incorporation of GO significantly improved the resistance of pervious concrete to freeze/thaw cycles and ambient-temperature salt attack. The specimens were examined using X-ray diffraction, which revealed that the mineralogy and the chemical composition of fly ash pastes differ considerably from those of cement pastes. Nuclear magnetic resonance was used to study the chemical structure and ordering of different hydrates, and provided enhanced understanding of the freeze/thaw and salt scaling resistance of fly ash pervious concrete and the role of GO

    Documentation of endangered Cosao “green codes” in Yunnan, China

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    The Cosao people, a small ethnic group living in Yunnan, southwest China, have a population of 149 people, living in 47 households (2013).The local government grouped them together with the Hani nationality in 2004. Cosao has no ISO code yet for it has not been previously reported in the literature. The Cosao peoplespeaking a southern Yi language of the Tibeto-Burman language family in Sino-Tibetan language phylum , do not have a written language. According to their oral history, they moved around in the borderlands between China and Laos and practiced slash-and-burn agriculture in the tropical forest. They practice traditional religion. They observe certain plant traits, and use these traits to encode and decode meanings and feelings to communicate with each other. The locals call this phenomenon “green codes” because they use plants to deliver messages and communicate within the tribe. The indigenous elders indicate that they used to utilize approximately 400 plants to express meanings and feelings covering love, ethics, prayer, number, birth, offering sacrifices to gods and ancestors, etc. This paper describes the Cosao people’s unique green codes: the plant messages, natural and cultural traits, highlighting linguistic encoding and decoding, and their domains of usage. Data discussed in this paper were collected by digital recording equipment, interviews, observation and description. The findings will provide evidence that biodiversity is decreasing at an alarming rate with the destruction of the local forests. Facing an economic transition, cultural shift and increased mobile phone usage, the majority of the Cosao have become bilingual or multi-lingual, giving up their mother tongue and their unique green codes. The stories, culture and traditional knowledge about the plants are disappearing due to the development of rubber plantations and the deterioration of their ecology. Therefore, only a few Cosao elders can still recall some of the names of plants in their mother tongue. Some plants can only be found within a few dozen kilometers because of the loss of forests. Hence, it is extremely urgent that the endangered language and green codes of the Cosao people be documented

    Factors in Gestational Diabetes Mellitus Predicting the Needs for Insulin Therapy

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    Objective. To identify factors predicting the need for insulin therapy in pregnancies complicated by gestational diabetes mellitus (GDM). Methods. A total of 1352 patients with GDM diagnosed by the 75-g/2-h oral glucose tolerance test (OGTT) were enrolled in this study. Univariate and multivariate analysis were performed; receiver operating characteristics (ROC) were also drawn. Results. There was a significant difference in factors such as maternal age, pregestational BMI, first visit SBP, first visit DBP, FBG of first visit, FBG at time of OGTT, 75-g OGTT glucose value (fasting, after 1 h and 2 h), and serum HbA1c level at diagnosis between patients with insulin therapy and patients with medical nutrition therapy (MNT) alone. Multivariate analysis showed that higher FBG at time of OGTT, first 75 g OGTT 2 h plasma glucose, and HbA1c concentration at diagnosis lead to more likely need of insulin therapy. Conclusion. The probability of insulin therapy can be estimated in pregnant women with GDM based on fasting and 2 h glucose values during OGTT and HbA1c value at diagnosis of GDM

    Effects of oil-in-water based nanolubricant containing TiO2 nanoparticles in hot rolling of 304 stainless steel

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    Energy saving and improvement of product quality are of crucial importance in hot rolling of 304 stainless steel. In this paper, oil-in-water (O/W) based nanolubricants containing TiO2 nanoparticles were developed to reduce the rolling force and improve the surface quality of rolled 304 stainless steel product. Practical hot rolling tests with and without application of lubricant were conducted to systematically investigate the effects of the developed O/W based nanolubricants on the rolling force, surface roughness, oxide scale thickness and tribological behaviour. The obtained results indicate that the nanoparticles can enter the deform zone with oil droplets to take a lubrication effect. The optimal lubrication effect can be achieved when the O/W (1% oil mass fraction) based nanolubricant with a TiO2 mass fraction of 1.5% was applied. The novel nanolubricant has a great potential to be applied in the hot steel rolling, to realise the cost-effective and environmental-friendly manufacturing process

    Construction and Characterization of a Bacterial Artificial Chromosome Library for the Hexaploid Wheat Line 92R137

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    For map-based cloning of genes conferring important traits in the hexaploid wheat line 92R137, a bacterial artificial chromosome (BAC) library, including two sublibraries, was constructed using the genomic DNA of 92R137 digested with restriction enzymes HindIII and BamHI. The BAC library was composed of total 765,696 clones, of which 390,144 were from the HindIII digestion and 375,552 from the BamHI digestion. Through pulsed-field gel electrophoresis (PFGE) analysis of 453 clones randomly selected from the HindIII sublibrary and 573 clones from the BamHI sublibrary, the average insert sizes were estimated as 129 and 113 kb, respectively. Thus, the HindIII sublibrary was estimated to have a 3.01-fold coverage and the BamHI sublibrary a 2.53-fold coverage based on the estimated hexaploid wheat genome size of 16,700 Mb. The 765,696 clones were arrayed in 1,994 384-well plates. All clones were also arranged into plate pools and further arranged into 5-dimensional (5D) pools. The probability of identifying a clone corresponding to any wheat DNA sequence (such as gene Yr26 for stripe rust resistance) from the library was estimated to be more than 99.6%. Through polymerase chain reaction screening the 5D pools with Xwe173, a marker tightly linked to Yr26, six BAC clones were successfully obtained. These results demonstrate that the BAC library is a valuable genomic resource for positional cloning of Yr26 and other genes of interest

    Association of gestational hypertriglyceridemia, diabetes with serum ferritin levels in early pregnancy: a retrospective cohort study

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    AimsPrevious studies showed conflicting results linking body iron stores to the risk of gestational diabetes mellitus (GDM) and dyslipidemia. We aim to investigate the relationship between serum ferritin, and the prevalence of GDM, insulin resistance (IR) and hypertriglyceridemia.MethodsA total of 781 singleton pregnant women of gestation in Shanghai General Hospital took part in the retrospective cohort study conducted. The participants were divided into four groups by quartiles of serum ferritin levels (Q1–4). Binary logistic regressions were used to examine the strength of association between the different traits and the serum ferritin (sFer) quartiles separately, where Q1 (lowest ferritin quartile) was taken as the base reference. One-way ANOVA was adopted to compare the averages of the different variables across Sfer quartiles.ResultsCompared with the lowest serum ferritin quartile (Q1), the ORs for Q3, and Q4 in our population were 1.79 (1.01–2.646), and 2.07 (1.089-2.562) respectively and this trend persisted even after adjusted for age and pre-BMI. Women with higher serum ferritin quartile including Q3 (OR=2.182, 95%CI=1.729-5.527, P=0.003) and Q4(OR=3.137, 95%CI=3.137-8.523, P<0.01)are prone to develop insulin resistance disorders. No significant difference was observed between sFer concentrations and gestational hypertriglyceridemia(GTG) in the comparison among these 4 groups across logistic regressions but TG was found positively correlated with increased ferritin values in the second trimester.ConclusionsIncreased concentrations of plasma ferritin in early pregnancy are significantly and positively associated with insulin resistance and incidence of GDM but not gestational dyslipidemia. Further clinical studies are warranted to determine whether it is necessary to encourage pregnant women to take iron supplement as a part of routine antenatal care

    Effect of continuous glucose monitoring compared with self-monitoring of blood glucose in gestational diabetes patients with HbA1c<6%: a randomized controlled trial

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    ObjectiveThis study evaluated the effect of continuous glucose monitoring (CGM) versus self-monitored blood glucose (SMGB) in gestational diabetes mellitus (GDM) with hemoglobin A1c (HbA1c) &lt;6%.MethodsFrom January 2019 to February 2021, 154 GDM patients with HbA1c&lt;6% at 24–28 gestational weeks were recruited and assigned randomly to either SMBG only or CGM in addition to SMBG, with 77 participants in each group. CGM was used in combination with fingertip blood glucose monitoring every four weeks until antepartum in the CGM group, while in the SMBG group, fingertip blood glucose monitoring was applied. The CGM metrics were evaluated after 8 weeks, HbA1c levels before delivery, gestational weight gain (GWG), adverse pregnancy outcomes and CGM medical costs were compared between the two groups.ResultsCompared with patients in the SMBG group, the CGM group patients had similar times in range (TIRs) after 8 weeks (100.00% (93.75-100.00%) versus 99.14% (90.97-100.00%), p=0.183) and HbA1c levels before delivery (5.31 ± 0.06% versus 5.35 ± 0.06%, p=0.599). The proportion with GWG within recommendations was higher in the CGM group (59.7% versus 40.3%, p=0.046), and the newborn birth weight was lower (3123.79 ± 369.58 g versus 3291.56 ± 386.59 g, p=0.015). There were no significant differences in prenatal or obstetric outcomes, e.g., cesarean delivery rate, hypertensive disorders, preterm births, macrosomia, hyperbilirubinemia, neonatal hypoglycemia, respiratory distress, and neonatal intensive care unit admission &gt;24 h, between the two groups. Considering glucose monitoring, SMBG group patients showed a lower cost than CGM group patients.ConclusionsFor GDM patients with HbA1c&lt;6%, regular SMBG is a more economical blood glucose monitoring method and can achieve a similar performance in glycemic control as CGM, while CGM is beneficial for ideal GWG
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