应对供水突发公共事件的炭砂滤池应急改造技术研究

依托武汉某水厂开展中试考察不同炭砂配比对水中污染物的去除效果,探究不同冲洗参数对冲洗效果的影响。结果表明,最佳炭层和砂层厚度为800 mm和500 mm,最佳冲洗方式为16 L/(m^(2)·s)气冲3 min、间隔2 min、13 L/(m^(2)·s)水冲9 min。1#炭砂滤柱对氨和高锰酸盐指数的平均去除率分别为46.99%和54.81%,其对有机物的去除效果明显优于砂滤柱,当进水浊度低于2 NTU时,1#炭砂滤柱浊度平均去除率可达85.67%,出水满足厂区滤后水浊度指标的要求。采用最佳炭砂配比和冲洗方式,1#炭砂滤柱滤后水浊度和高锰酸盐指数去除率可达89.56%和66.27%。结合上述中试结果,并通过对实际工程中砂滤池及炭砂滤池进行调研,形成一套完整的炭砂滤池工程改造方案,为应对供水突发事件时砂滤池改造为炭砂滤池提供一定的理论指导。

Numerical investigation of flow over a two-dimensional square cylinder with a synthetic jet generated by a bi-frequency signal

The flow around a square cylinder with a synthetic jet positioned at the rear surface is numerically investigated with the unsteady Reynolds-averaged Navier-Stokes(URANS)method.Instead of the typical sinusoidal wave,a bi-frequency signal is adopted to generate the synthetic jet.The bi-frequency signal consists of a basic sinusoidal wave and a high-frequency wave.Cases with various amplitudes of the high-frequency component are simulated.It is found that synthetic jets actuated by bi-frequency signals can realize better drag reduction with lower energy consumption when appropriate parameter sets are applied.A new quantity,i.e.,the actuation efficiency Ae,is used to evaluate the controlling efficiency.The actuation efficiency Ae reaches its maximum of 0.2668 when the amplitude of the superposed high-frequency signal is 7.5%of the basic signal.The vortex structures and frequency characteristics are subsequently analyzed to investigate the mechanism of the optimization of the bi-frequency signal.When the synthetic jet is actuated by a single-frequency signal with a characteristic velocity of 0.112 m/s,the wake is asymmetrical.The alternative deflection of vortex pairs and the peak at half of the excitation frequency in the power spectral density(PSD)function are detected.In the bi-frequency cases with the same characteristic velocity,the wake gradually turns to be symmetrical with the increase in the amplitude of the high-frequency component.Meanwhile,the deflection of the vortex pairs and the peak at half of the excitation frequency gradually disappear as well.

Titanium particles in peri-implantitis:distribution,pathogenesis and prospects

Peri-implantitis is one of the most important biological complications in the field of oral implantology.Identifying the causative factors of peri-implant inflammation and osteolysis is crucial for the disease’s prevention and treatment.The underlying risk factors and detailed pathogenesis of peri-implantitis remain to be elucidated.Titanium-based implants as the most widely used implant inevitably release titanium particles into the surrounding tissue.Notably,the concentration of titanium particles increases significantly at peri-implantitis sites,suggesting titanium particles as a potential risk factor for the condition.Previous studies have indicated that titanium particles can induce peripheral osteolysis and foster the development of aseptic osteoarthritis in orthopedic joint replacement.However,it remains unconfirmed whether this phenomenon also triggers inflammation and bone resorption in peri-implant tissues.This review summarizes the distribution of titanium particles around the implant,the potential roles in peri-implantitis and the prevalent prevention strategies,which expects to provide new directions for the study of the pathogenesis and treatment of peri-implantitis.

论“双减”的价值逻辑与回归教育原点

“双减”的出场体现出了教育高质量发展的时代精神,是对新时代学校教育以人为本理念的重申。促使学校教育回归育人原点是“双减”的精神实质,对此,需要从教育的生活探究本性、教育关系的丰富和教育行动品格的彰显三方面来阐明其价值逻辑。体现在实践层面,“双减”以促使教师教育观念的变革、教育时空的拓展、家校社育人共同体的建构和教师工作品质的提升推动着学校教育的整体变革。为进一步深化“双减”以促使学校教育回归原点,需要通过激发教育活力、改善教育生态与创新教育方式,协同推动“双减”价值追求的现实化。

血浆置换治疗乙肝肝衰竭的疗效及影响因素分析

目的探讨血浆置换治疗乙肝所致肝衰竭的疗效及影响因素。方法回顾性分析73例血浆置换治疗乙肝所致肝衰竭患者的临床资料,根据转归分为有效组和无效组,对可能影响疗效的因素:实验室指标、年龄、性别、肝衰竭分期、HBVDNA、是否有肝硬化及并发症(腹水、腹膜炎、肝性脑病和电解质紊乱)进行Logistic回归分析。结果单因素和多因素Logistic回归分析显示血清总胆红素和肝衰竭分期是影响血浆置换治疗乙肝肝衰竭疗效的危险因素(P<0.05),相对危险度分别为0.995、9.368。结论血清总胆红素浓度和肝衰竭分期是影响血浆置换治疗乙肝肝衰竭疗效的危险因素。

宜昌台三类地倾斜仪观测数据的对比研究

研究采用宜昌地震台水管倾斜仪、VP型垂直摆倾斜仪、VS型垂直摆倾斜仪三类地倾斜仪的观测数据,进行潮汐响应函数和非潮汐参数和地震响应对比。结果显示:(1)三类倾斜仪M 2波潮汐因子NS向普遍小于EW向,NS向容易受局部观测环境的影响;三类倾斜仪EW向潮汐速率略大于NS向,VS仪漂移最大,其次VP仪,而水管仪三者中漂移最小。总的来说,仪器的稳定性和精度方面,水管仪最好,VP倾斜仪次之,垂直摆最低。(2)三类倾斜仪易受观测环境干扰,数据产生不同程度噪声,由于不同仪器的性能差异,造成三类观测数据不同步,为鉴别真实的地壳形变信息,应对观测数据做去干扰处理,将不同观测的物理量互相验证,对数据质量较差的观测系统应进行合理化改造。

Characteristics and advantages of adeno-associated virus vector-mediated gene therapy for neurodegenerative diseases

Common neurodegenerative diseases of the central nervous system are characterized by progressive damage to the function of neurons, even leading to the permanent loss of function. Gene therapy via gene replacement or gene correction provides the potential for transformative therapies to delay or possibly stop further progression of the neurodegenerative disease in affected patients. Adeno-associated virus has been the vector of choice in recent clinical trials of therapies for neurodegenerative diseases due to its safety and efficiency in mediating gene transfer to the central nervous system. This review aims to discuss and summarize the progress and clinical applications of adeno-associated virus in neurodegenerative disease in central nervous system. Results from some clinical trials and successful cases of central neurodegenerative diseases deserve further study and exploration.

Coronary CT Angiography Using Low Iodine Delivery Rate and Tube Voltage Determined by Body Mass Index:Superiority in Clinical Practice

To explore the feasibility and superiority of iodine delivery rate(IDR)and tube voltage determined by patients'body mass index(BMI)in coronary CT angiography(CCTA),a total of 1567 patients undertaking CCTA during Feb.and Dec.2016 were enrolled and divided into two groups.In the control group,the IDR and tube voltage were fixed,while in the experimental group,the IDR and tube voltage were determined by patients,BMI.The volume of iodinated contrast media(ICM),extravasation rate,extravasation volume,extravasation recovery interval,incidence rate of adverse reactions,effective dose(ED)and image quality of the two groups were compared.The experiments demonstrated that the ICM volume,extravasation rate,extravasation volume,extravasation recovery interval,incidence of adverse reactions and ED were lower or shorter in the experimental group than in the control group,and the differences were statistically significant(all P<0.05).However,there were no significant differences in the mean CT value,image noise,signal to noise ratio and contrast to noise ratio between the two groups(all P<0.05),which were consistent with the diagnosticians*subjective evaluation outcomes.Our findings suggested that in CCTA,it is feasible to determine the IDR and tube voltage based on patients'BMI;low tube voltage and IDR are superior to the fixed tube voltage and IDR and are worthy of clinical promotion.

Atsttrin reduces lipopolysaccharide-induced neuroinflammation by inhibiting the nuclear factor kappa B signaling pathway

Progranulin is closely related to neuronal survival in a neuroinflammatory mouse model and attenuates inflammatory reactions. Atsttrin is an engineered protein composed of three progranulin fragments and has been shown to have an effect similar to that of progranulin. Atsttrin has anti-inflammatory actions in multiple arthritis mouse models, and it protects against further arthritis development. However, whether Atsttrin has a role in neuroinflammation remains to be elucidated. In this study, we produced a neuroinflammatory mouse model by intracerebroventricular injection of 1 μL lipopolysaccharide(10 μg/μL). Atsttrin(2.5 mg/kg) was administered via intraperitoneal injection every 3 days over a period of 7 days before intracerebroventricular injection of 1 μL lipopolysaccharide(10 μg/μL). In addition, astrocyte cultures were treated with 0, 100 or 300 ng/mL lipopolysaccharide, with 200 ng/mL Atsttrin simultaneously. Immunohistochemistry, enzyme-linked immunosorbent assay and real-time reverse transcription-polymerase chain reaction were performed to examine the protein and mRNA levels of inflammatory mediators and to assess activation of the nuclear factor kappa B signaling pathway. Progranulin expression in the brain of wild-type mice and in astrocyte cultures was increased after lipopolysaccharide administration. The protein and mRNA expression levels of tumor necrosis factor-α, interleukin-1β and inducible nitric oxide synthase were increased in the brain of progranulin knockout mice after lipopolysaccharide administration. Atsttrin treatment reduced the lipopolysaccharide-induced increase in the protein and mRNA levels of tumor necrosis factor-α, interleukin-1β, matrix metalloproteinase-3 and inducible nitric oxide synthase in the brain of progranulin knockout mice. Atsttrin also reduced the expression of cyclooxygenase-2, inducible nitric oxide synthase and matrix metalloproteinase 3 mRNA in lipopolysaccharide-treated astrocytes in vitro, and decreased the concentration of tumor necrosis factor α and interleukin-1β in the supernatant. Furthermore, Atsttrin significantly reduced the levels of phospho-nuclear factor kappa B inhibitor α in the brain of lipopolysaccharide-treated progranulin knockout mice and astrocytes, and it decreased the expression of nuclear factor kappa B2 in astrocytes. Collectively, our findings show that the anti-neuroinflammatory effect of Atsttrin involves inhibiton of the nuclear factor kappa B signaling pathway, and they suggest that Atsttrin may have clinical potential in neuroinflammatory therapy.

Rno_circ_0005139 regulates apoptosis by targeting Wnt5a in rat anorectal malformations

BACKGROUND The molecular mechanisms underlying anorectal malformations(ARM)are not fully established.Circular RNAs(circRNAs)are new born non-coding RNAs,and their role in ARM is unclear.We assumed that rno_circ_0005139 influences apoptosis and proliferation by acting as a miR-324-3p sponge,and downregulating Wnt5a in ARM.AIM To identify the differential expression of circRNAs and mRNAs in a rat ARM model.METHODS Sixty-six pregnant Wistar rats were randomly divided into two groups:ARM group(2-imidazolidinethione-induced)and control groups.Embryos were harvested by cesarean delivery,and anorectal tissue was taken on embryonic days 16(E16),17(E17),19(E19),and 21(E21).RNA sequencing and gene microarray analysis was used to identify differentially expressed circRNAs and mRNAs in the ARM in a rat model.We selected 6 circRNAs and 3 mRNAs in the Wnt signal pathway from the result of the RNA sequencing and gene microarray analysis,and quantitative reverse transcription polymerase chain reaction was performed to evaluate their tissue expression.According to bioinformatics prediction,rno_circ_0005139 acted as a miR-324-3p sponge to regulate the expression of Wnt5a.We chose rno_circ_0005139 and Wnt5a as the final candidates.We tested the function of rno_circ_0005139 and the binding sites between rno_circ_0005139 and miR-324-3p,miR-324-3p and Wnt5a by luciferase assays.Co-transfection of rno_circ_0005139 and miR-324-3p was to verify their functional consistency.RESULTS We identified 38 upregulated and 42 downregulated circRNAs on E17(P<0.05),and 301 mRNAs were upregulated and 256 downregulated in the ARM on E17(P<0.05,fold-change>2.0).We found that rno_circ_0006880 and rno_circ_0011386 were upregulated,whereas rno_circ_0000436,rno_circ_0005139,rno_circ_0009285,rno_circ_0014367,Wnt5a,Wnt10b,and Wnt2b were downregulated in ARM tissues.According to bioinformatics prediction,rno_circ_0005139 acted as a miR-324-3p sponge to regulate the expression of Wnt5a.We chose rno_circ_0005139 and Wnt5a as the final candidates.Because the role and molecular mechanism of rno_circ_0005139 are poorly understood,its effect on apoptosis and proliferation was investigated by in vitro plasmid transfection.A luciferase experiment showed that rno_circ_0005139 could bind with miR-324-3p,which negatively regulated Wnt5a expression.The expression of miR-324-3p was significantly higher in ARM anorectal tissues than that in control group on E17 and E19;Wnt5a expression showed the opposite trend.In addition,a miR-324-3p inhibitor attenuated the effects of rno_circ_0005139 knockdown on ARM development.CONCLUSION Rno_circ_0005139 influences cell proliferation and apoptosis by acting as a miR-324-3p sponge,thereby downregulating Wnt5a in ARM.Accordingly,rno_circ_0005139,miR-324-3p,and Wnt5a could be targeted therapeutic factors for ARM.

特殊时期水厂安全运行保障应急预案研究

通过分析新冠肺炎疫情期间武汉市水厂供水特点、制水风险及应急预案的体系,总结了出水水质达标和安全保供等方面的运行管理经验和技术保障措施,构建了疫情防控期间水厂安全运行保障专项应急预案体系,以提升水厂应对重大突发公共卫生事件的应急能力和保障水平,也为在发生类似突发事件时有效保障水厂安全运行和优质供水提供宝贵的实践经验.

后冬奥时代我国冰雪竞技体育发展的SWOT分析

通过运用文献资料、数理统计等方法,本文对北京冬奥会赛事和世界冰雪体育强国竞技优势进行了分析比对,结合我国冰雪竞技体育实力现状、发展历史机遇以及现实挑战,探索出中国冰雪竞技体育的可持续性发展途径,即:大力推广冰雪体育,扩大冰雪体育人口;注重冰雪体育后备人才培育,推进冰雪竞技体育均衡发展;加强冰雪文化产业发展,建设特色冰雪运动产品。

清水池观察级水下机器人巡检装置设计与实践

针对清水池巡检作业中存在需要停产、作业环境差、劳动强度大和成本高等问题,提出了清水池水下机器人巡检的技术方案。在对清水池水下巡检作业进行功能需求、性能需求分析的基础上,给出了装置的具体设计方案,并集成了一套清水池观察级水下机器人巡检装置。在4座清水池进行了水下视频检查、水样采集、泥砂沉积测量和杂物拾取等实验验证,结果表明该技术方案经济、可行,装置实现了清水池不停产水下巡检作业的目标。

Full-polarization angular spectrum modeling of scattered light modulation

The exact physical modeling for scattered light modulation is critical in phototherapy,biomedical imaging,and free-space optical communications.In particular,the angular spectrum modeling of scattered light has attracted considerable attention,but the existing angular spectrum models neglect the polarization of photons,degrading their performance.Here,we propose a full-polarization angular spectrum model(fpASM)to take the polarization into account.This model involves a combination of the optical field changes and free-space angular spectrum diffraction,and enables an investigation of the influence of polarization-related factors on the performance of scattered light modulation.By establishing the relationship between various model parameters and macroscopic scattering properties,our model can effectively characterize various depolarization conditions.As a demonstration,we apply the model in the time-reversal data transmission and anti-scattering light focusing.Our method allows the analysis of various depolarization scattering events and benefits applications related to scattered light modulation.

Complex transmission matrix retrieval for a highly scattering medium via regional phase differentiation

Accurately measuring the complex transmission matrix(CTM) of the scattering medium(SM) holds critical significance for applications in anti-scattering optical imaging, phototherapy, and optical neural networks. Noninterferometric approaches, utilizing phase retrieval algorithms, can robustly extract the CTM from the speckle patterns formed by multiple probing fields traversing the SM. However, in cases where an amplitude-type spatial light modulator is employed for probing field modulation, the absence of phase control frequently results in the convergence towards a local optimum, undermining the measurement accuracy. Here, we propose a high-accuracy CTM retrieval(CTMR) approach based on regional phase differentiation(RPD). It incorporates a sequence of additional phase masks into the probing fields, imposing a priori constraints on the phase retrieval algorithms. By distinguishing the variance of speckle patterns produced by different phase masks, the RPD-CTMR can effectively direct the algorithm towards a solution that closely approximates the CTM of the SM. We built a prototype of a digital micromirror device modulated RPD-CTMR. By accurately measuring the CTM of diffusers, we achieved an enhancement in the peak-to-background ratio of anti-scattering focusing by a factor of 3.6, alongside a reduction in the bit error rate of anti-scattering image transmission by a factor of 24. Our proposed approach aims to facilitate precise modulation of scattered optical fields, thereby fostering advancements in diverse fields including high-resolution microscopy, biomedical optical imaging, and optical communications.

Correlation of Vascular Endothelial Growth Factor Production with Photochemical Reaction-induced Retinal Edema

Background： Retinal edema is the major complication of retinal vein occlusion and diabetic retinopathy; it can damage visual function by influencing macular region. This study was to establish a rat retinal edema model and explore the related VEGF expression and observe the responses to anti-VEGF drugs in this model. Methods： A rat retinal edema model was established by inducing photochemical reaction using a 532 nm laser after the intravenous injection of Erythrosin B. Immediately after the laser treatment, models were given intravitreal injections of Ranibizumab or Conbercept to inhibit VEGF expression, and the changes of retinal thickness were measured. Retinal edema was observed using fundus photography （FP）, optical coherence tomography （OCT）, and fluoresce in fundus angiography （FFA） at 0, 1, 2, 4, 7 and 14 days after intervention. The retinal VEGF expression was measured using enzyme-linked immunosorbent assay （ELISA） and western blotting at each time point. The rat retinal edema model was also used to verify the function of anti-VEGF polypeptide ZY1. Results： Both retinal edema and vascular leakage were clearly observed at 1, 2 and 4 days after photochemical induction and the retinal thickness increased notably over the same period. The retinal VEGF expression peaked at day 1 and retina became thickening simultaneously. After the interventions, the VEGF expression of the Ranibizumab and Conbercept groups decreased at each time point compared to the edema group （26.90 ± 3.57 vs. 40.29 ± 6.68, F = 31.269 on day 1 and 22.36 ± 1.12 vs. 29.92 ± 0.93 F = 163.789 on day 2, both P 〈 0.01）; the mean RT （278 ± 4 vs. 288 ± 3, F = 134.190 on day 1 and 274 ± 7 vs. 284 ± 6, F = 64.367 on day 2, both P 〈 0.05） and vascular leakage in these groups also decreased. The same results were observed in the ZY1 group, particularly at day 2 （P 〈 0.05）. Conclusions： This retinal edema model induced by a photochemical reaction is reliable and repeatable. Induced edema increases expression of VEGF. This model can be used to test new drugs.

Anti-scattering light focusing by fast wavefront shaping based on multi-pixel encoded digital-micromirror device

Speed and enhancement are the two most important metrics for anti-scattering light focusing by wavefront shaping(WS),which requires a spatial light modulator with a large number of modulation modes and a fast speed of response.Among the commercial modulators,the digital-micromirror device(DMD)is the sole solution providing millions of modulation modes and a pattern rate higher than 20 kHz.Thus,it has the potential to accelerate the process of anti-scattering light focusing with a high enhancement.Nevertheless,modulating light in a binary mode by the DMD restricts both the speed and enhancement seriously.Here,we propose a multi-pixel encoded DMD-based WS method by combining multiple micromirrors into a single modulation unit to overcome the drawbacks of binary modulation.In addition,to efficiently optimize the wavefront,we adopted separable natural evolution strategies(SNES),which could carry out a global search against a noisy environment.Compared with the state-of-the-art DMD-based WS method,the proposed method increased the speed of optimization and enhancement of focus by a factor of 179 and 16,respectively.In our demonstration,we achieved 10 foci with homogeneous brightness at a high speed and formed W-and S-shape patterns against the scattering medium.The experimental results suggest that the proposed method will pave a new avenue for WS in the applications of biomedical imaging,photon therapy,optogenetics,dynamic holographic display,etc.

Near-wall topological patterns and flow structures over a simplified Danaus plexippus model

Studies on the high-lift mechanisms of butterfly gliding flights shed light on the design of the micro air vehicles.The flow field around a simplified Danaus plexippus model is investigated using the hydrogen bubble visualization and the Particle Image Velocimetry(PIV)techniques.There are three near-wall topological patterns with different Angles of Attack(AoAs):the separation bubble,the Leading-Edge Vortex(LEV)and the high Ao As flow.For the separation bubble pattern,two saddles and two foci form in the middle of the model.The features of the LEV pattern are the leading-edge separation lines.The topological characteristics of the separation lines are changed by the interaction between the LEV and the Wing-Tip Vortex(WTV).For the high Ao As flow pattern,four unstable foci are found at the forewing and the hindwing respectively.The angle between the trajectory of the WTV and the model increases with increasing Ao A even though the slope of the WTV angle versus Ao A curve declines at the moderate AoAs.