三尖瓣下移畸形合并房间隔缺损20例手术治疗结果分析

目的 分析三尖瓣下移畸形合并房间隔缺损外科手术治疗处理策略及近期随访结果。方法 回顾性分析2017年9月至2021年6月诊治的20例三尖瓣下移畸形合并房间隔缺损患者的临床资料及随访结果,并对该组患者术前及术后超声心动图结果进行统计分析。结果 16例患者选择双心室矫治术,其中采用水平房化心室折叠三尖瓣成形术(Danielsons术式)2例,采用垂直房化心室折叠三尖瓣成形术(Carpentier术式)4例,锥形重建术10例;2例患者选择一个半心室矫正术(三尖瓣成形术加双向Glenn手术);2例患者行双向Glenn术。20例患者合并的房间隔缺损在进行体外循环矫治畸形时均一期闭合。术后1、3、6、12个月,患者右心室大小较术前明显缩小(P <0.05),心功能(左心室射血分数)明显提高(P <0.05)。结论 三尖瓣下移畸形合并房间隔缺损手术治疗应遵循个体化的治疗原则,双心室矫治术仍是首选的治疗方法,一期关闭房间隔缺损,可以获得良好的治疗效果。

维生素D2对老年肱骨近端骨质疏松性骨折术后的疗效分析

目的研究维生素D2对老年肱骨近端骨质疏松性骨折术后的疗效影响。方法纳入老年肱骨近端骨质疏松性骨折患者52例,随机分为实验组(n=27)、对照组(n=25)。实验组行锁定钢板内固定术的同时连续肌肉注射维生素D2 40万单位/日,共七日,对照组仅行锁定钢板内固定术。对比两组术后血清25OHD水平、骨折愈合时间、肩关节Neer功能评分,分析锁定钢板内固定术结合维生素D2在老年肱骨近端骨质疏松性骨折患者中的疗效。结果术后随访6个月时实验组患者肩关节Neer功能评分显著高于对照组(P <0.01),优良率(P <0.05)及并发症发生率均低于对照组,实验组术后骨折愈合时间明显低于对照组(P <0.01),实验组血清25OHD水平在6周、12周、24周时均显著高于对照组(P <0.01)。结论维生素D2能有效缩短老年肱骨近端骨质疏松性骨折患者术后骨折愈合时间,改善患者肩关节功能。

电磁兼容性测试与抑制技术探讨

电路系统中的电磁兼容性非常重要,如何对电磁兼容性进行测试,并抑制各种干扰,使其兼容性得到增强,是相关从业人员应深入思考的问题。为此,文中对电子电器设备的电磁兼容测试工作中存在的问题进行了分析,并提出了优化电路系统、屏蔽干扰、减少导线串扰及滤波等措施,使电路系统中的兼容性得以优化。

K-Rod动态稳定系统治疗腰椎退行性疾病的中期疗效

目的探讨K-Rod动态稳定系统治疗腰椎退行性疾病的中期疗效及其对邻近上位节段的影响。方法回顾性分析昆明市第一人民医院骨科2011年2月至2013年6月65例采用K-Rod动态稳定系统治疗腰椎退行性疾病患者的临床资料。其中,男31例,女34例,年龄21~73岁,平均(53.4±10.8)岁;融合组(n=21),非融合组(n=20),“融合+非融合”组(n=24)。记录术中失血量、手术时间、住院时间及并发症;根据术前及各随访时间腰痛、下肢痛VAS评分,ODI评分评价临床疗效。比较3组病例术前及随访时间腰椎侧位X线片、腰椎MRI手术及邻近上位节段椎间隙高度、椎间盘退变Pfirrmann's分级情况。结果经72~84个月,平均(72.0±8.6)个月随访。3组组内术后3、6个月及末次随访时腰痛、下肢痛VAS评分及ODI评分与术前比较,差异均有统计学意义(P<0.05)。末次随访时,腰痛、下肢痛VAS评分改善率,融合组为66.4%、76.7%,非融合组为84.4%、72.4%,“融合+非融合”组为70.8%、77.8%;邻近上位节段椎间盘退变Pfirrmann's分级:非融合组、“融合+非融合”组与术前比较差异无统计学意义(P>0.05),融合组与术前比较差异有统计学意义(P<0.05)。手术节段椎间高度指数:3组组内术后1周与术前比较,差异有统计学意义(P<0.05),术后3个月、6个月、末次随访时与术后1周比较差异无统计学意义(P>0.05)。邻近节段椎间高度指数:非融合组、“融合+非融合”组术后1周、3个月、6个月、末次随访时与术前比较,差异无统计学意义(P>0.05);融合组末次随访与术前比较,差异有统计学意义(P<0.05)。结论应用K-Rod动态稳定系统对腰椎退行性疾病行非融合及“非融合+融合”术治疗,中期随访疗效良好,一定程度上可延缓邻近节段椎间盘退变,对退变的椎间盘有一定的保护作用。

后路单椎体内固定治疗寰椎不稳定性骨折

目的观察后路椎弓根螺钉治疗寰椎不稳定性骨折的临床疗效。方法对2011年6月~2016年8月收治的16例寰椎不稳定性骨折患者的资料进行回顾性分析。其中,男10例,女6例;年龄22~46岁,平均(32.9±6.7)岁。患者均存在枕颈部疼痛、活动受限症状,均无脊髓损伤症状。骨折类型:Gehweiler分型Ⅲa型5例、Ⅲb型7例、Ⅳ型4例;Ⅲa型合并下颈椎损伤1例、Ⅲb型合并下颈椎损伤1例;Ⅲb型7例中,横韧带损伤Dickman分型Ⅱa型3例、Ⅱb型4例;Ⅳ型4例中,横韧带损伤Dickman分型Ⅱa型1例、Ⅱb型3例。术前均行颅骨牵引制动稳定骨折块,术前CT测量寰齿前间距(ADI)、记录枕颈部疼痛视觉模拟(VAS)评分,排除手术禁忌证后均行后路单椎体内固定治疗,记录手术时间、术中失血量及并发症情况,末次随访时复查CT寰齿前间距(ADI)、枕颈部VAS评分、颈椎活动范围(ROM),术后影像学检查评估骨折愈合情况。结果 16例患者均完成置钉操作;手术时间为60~90 min,平均(75.9±9.8)min;术中出血量为100~300 m L,平均(180±50.2)m L;未发生脊髓和椎动脉损伤。术后X线片及CT示2例单侧螺钉偏内致椎弓根内侧皮质破裂,但均无血管、神经损伤症状;其余螺钉位置良好。术后随访12~36个月,平均(21.1±6.1)个月。术前枕颈部VAS评分4~7分,平均(5.5±1.2)分;末次随访时枕颈部疼痛VAS评分0~3分,平均(1.3±0.9)分,与术前比较差异有统计学意义(P<0.05)。术前ADI值2.9~5.2mm,平均(4.2±0.7)mm,末次随访ADI值2.0~3.6mm,平均(2.8±0.5)mm,与术前比较差异有统计学意义(P<0.05)。末次随访颈部活动范围(ROM)前屈30°~42°,平均(35.12±3.8)°;后伸29°~38°,平均(33.3±2.8)°;左侧屈31°~46°,平均(37.8±4.0)°;右侧屈33°~48°,平均(38.9±4.8)°;左旋转47°~61°,平均(54.8±4.3)°;右旋转46°~60°,平均(53.3±4.3)°。术后6~9个月,平均(7±0.9)个月复查骨折断端达到骨性愈合,随访期间颈椎序列良好。未见内固定松动、断裂,无C1-2失稳。结论后路椎弓根螺钉固定治疗寰椎Gehweiler分型Ⅲ、Ⅳ型不稳定性骨折的临床疗效满意。

个人所得税改革主要影响及政策建议

长期以来,个人所得税一直是我国主体税种之一,2018年,我国个人所得税改革影响广泛、倍受关注。本次个人所得税改革主要内容为提高基本减除费用标准,新增多项专项附加扣除,扩大低档税率级距等内容,对我国税收结构和管理体制产生影响;同时,个人所得税与社会公众切身利益紧密相关,也受到社会各界广泛关注和热议。文章全面分析个税改革对税收收入、个人收入分配机制、消费、央行国库部门履职产生的影响,并提出政策建议。

基于包络信号的轴频电场深度换算方法

在仅利用水平时谐电偶极子对舰船轴频电场信号进行换算时,存在近场深度误差较大的问题。文中首先在仿真数据的基础上,明确了船体表面不同位置电流密度与轴地电阻值波动时的变化规律;其次,提出了基于包络信号的轴频电场深度换算方法,该方法在希尔伯特(Hilbert)变换计算轴频电场信号包络的基础上,将轴频电场近场的深度换算问题转化为包络信号等效静电场的近场换算问题,并利用点电荷模型建立了轴频电场信号包络在"空气—海水—海床"3层介质条件下的正演及反演模型。最后,分别利用4种阴极防腐状态下的船模试验数据对所提方法的有效性进行了检验,结果表明,所提方法能够较好地实现对轴频电场信号包络值的准确换算,以相对均方根误差作为评价准则,水深为1倍船模宽度的换算误差小于15%。文中方法可为舰船近场的轴频电场反演提供新的途径。

Design of a Three-Dimensional Centrifugal Fan with Controlled Blade Loading Approach

The high flow-rate centrifugal fan needs a three-dimensional impeller to achieve a high efficiency. In this paper, the design procedure of a high-efficiency three-dimensional centrifugal fan is presented. First, the main dimensions of the fan were calculated by using the conventional one-dimensional method. Then, the blade loading or the angular momentum distribution along the meridional streamline on the blade surfaces is prescribed. After that, the three-dimensional blade is determined by using the streamline curvature method. With the aid of numerical simulations, the performance of the three-dimensional fan was improved and some of the key influence factors were investigated. The analyses indicate that, as to the high flow-rate centrifugal fan, the Stanitz modified formula is recommended to calculate the separation radius, rb. A proper increase in the separation radius is beneficial for the fan’s performance. It is also indicated that a decrease in the angular momentum on the hub leads to an increase in total pressure efficiency, under the condition of a given constant mean angular momentum at the outlet of the blade. In addition, the installation of a fairing on the hub plate can improve the fan’s efficiency evidently when the streamline curvature method is adopted to design the three-dimensional impeller.

Development of a new field-deployable RT-qPCR workflow for COVID-19 detection

Background:Outbreaks of coronavirus disease 2019(COVID-19)have been recorded in different countries across the globe.The virus is highly contagious,hence early detection,isolation,and quarantine of infected patients will play an important role in containing the viral spread.Diagnosis in a mobile lab can aid to find infected patients in time.Methods:Here,we develop a field-deployable diagnostic workflow that can reliably detect COVID-19.Instruments used in this workflow can easily fit in a mobile cabin hospital and also be installed in the community.Different steps from sample inactivation to detection were optimized to find the fastest steps and portable instruments in the detection of COVID-19.Each step was compared to that of the normal laboratory diagnosis setup.Results:From the results,our proposed workflow(80 min)was two times faster compared to that of the normal laboratory workflow(183 min)and a maximum of 32 samples could be detected at each run.Additionally,we showed that using 1%Rewocid WK-30 could inactivate the novel coronavirus directly without affecting the overall detection results.Comparison of our workflow using an in-house assay to that of a commercially acquired assay produced highly reliable results.From the 250 hospital samples tested,there was a high concordance 247/250(98.8%)between the two assays.The in-house assay sensitivity and specificity were 116/116(100%)and 131/134(97.8%)compared to that of the commercial assay.Conclusion:Based on these results,we believe that our workflow is fast,reliable,adaptable and most importantly,field-deployable.

电子化模式下国库监督问题研究

随着国家金库电子工程不断推进,国库依靠“3T”系统作为信息处理系统的核心,收入和支出已基本实现了电子化、自动化、无纸化,提高了缴税业务效率和质量,国库资金拨付服务得到了显着改善,国库集中收付改革不断取得进展。国库业务电子化作为现代管理理念与信息技术发展的融合产品,有效提高了国库资金管理水平和运用效率,满足社会发展需求,突出了显著的应用优势。同时,国库业务电子化发展过程中也暴露出一些国库监督问题,亟待关注。

Structures and magnetic relaxation properties of cyclopentadienyl/β-diketonate/trispyrazolylborate hybridized dysprosium single-molecule magnets

The combination of cyclopentadiene,β-diketonate and tripyrazoylborate ligands with dysprosium ion afforded five mononuclear compounds:[(Cp)2Dy(Tp∗)](1Dy),[(Cp)Dy(Tp∗)Cl(THF)](2Dy),[(Cp)Dy(Tp)Cl(THF)](3Dy),[(DBM)Dy(Tp)Cl(THF)](4Dy),[{(Tp)Dy(DBM)_(2)(H_(2)O)}·THF](5Dy)(Cp=cyclopentadiene;Tp∗=hydrotris(3,5-dimethyl-1-pyrazolyl)borate;Tp=hydrotris(1-pyrazolyl)borate;DBM=dibenzoylmethanoate).Magnetic study revealed that 1Dy and 3Dy exhibited typical butterfly-type hysteresis.AC susceptibility study combined with ab initio calculations indicated that the magnetic relaxation behaviors of 1Dy–4Dy were governed by the Orbach and Raman processes under applied DC field.Moreover,3Dy showed two-step magnetic relaxation,which was attributed to the static disordering of the coordinated THF molecule.Magnetic anisotropy analysis indicated that it was the relative strength of the interactions between DyIII and surrounding ligands that determined the orientation of the magnetic easy axis.

Dalea:A Persistent Multi-Level Extendible Hashing with Improved Tail Performance

Persistent memory(PM)promises byte-addressability,large capacity,and durability.Main memory systems,such as key-value stores and in-memory databases,benefit from such features of PM.Due to the great popularity of hash-ing index in main memory systems,a number of research efforts are made to provide high average performance persistent hashing.However,suboptimal tail performance in terms of tail throughput and tail latency is still observed for existing persistent hashing.In this paper,we analyze major sources of suboptimal tail performance from key design issues of persis-tent hashing.We identify the global hash structure and concurrency control as remaining explorable design spaces for im-proving tail performance.We propose Directory-sharing Multi-level Extendible Hashing(Dalea)for PM.Dalea designs an-cestor link-based extendible hashing as well as fine-grained transient lock to address the two main sources(rehashing and locking)affecting tail performance.The evaluation results show that,compared with state-of-the-art persistent hashing Dash,Dalea achieves increased tail throughput by 4.1x and reduced tail latency by 5.4x.Moreover,in order to provide de-sign guidelines for improving tail performance,we adopt Dalea as a testbed to identify different impacts of four factors on tail performance,including fine-grained rehashing,transient locking,memory pre-allocation,and fingerprinting.

Design and application of new storage systems

A storage system is the core of a computer,and plays an important role in the sustainable development of emerging strategic industries,such as artificial intelligence,big data,cloud computing,and the Internet of Things.Storage stack access is a major factor restricting the performance of data-intensive systems because of the increasing performance of processors and network devices.

Host metabolism dysregulation and cell tropism identification in human airway and alveolar organoids upon SARS-CoV-2 infection

The coronavirus disease 2019(COVID-19)pandemic is caused by infection with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which is spread primary via respiratory droplets and infects the lungs.Currently widely used cell lines and animals are unable to accurately mimic human physiological conditions because of the abnormal status of cell lines(transformed or cancer cells)and species differences between animals and humans.Organoids are stem cell-derived selforganized three-dimensional culture in vitro and model the physiological conditions of natural organs.Here we showed that SARS-CoV-2 infected and extensively replicated in human embryonic stem cells(hESCs)-derived lung organoids,including airway and alveolar organoids which covered the complete infection and spread route for SARS-CoV-2 within lungs.The infected ceils were ciliated,club,and alveolar type 2(AT2)cells,which were sequentially located from the proximal to the distal airway and terminal alveoli,respectively.Additionally,RNA-seq revealed early cell response to virus infection including an unexpected downregulation of the metabolic processes,especially lipid metabolism,in addition to the well-known upregulation of immune response.Further,Remdesivir and a human neutralizing antibody potently inhibited SARS-CoV-2 replication in lung organoids.Therefore,human lung organoids can serve as a pathophysiological model to investigate the underlying mechanism of SARS-CoV-2 infection and to discover and test therapeutic drugs for COVID-19.

Evaluation of sulfur trioxide detection with online isopropanol absorption method

Measurement of the SO3 concentration in flue gas is important to estimate the acid dew point and to control corrosion of downstream equipment. SO3 measurement is a difficult question since SO3 is a highly reactive gas, and its concentration is generally two orders of magnitude lower than the SO2 concentration. The SO3 concentration can be measured online by the isopropanol absorption method; however, the reliability of the test results is relatively low. This work aims to find the error sources and to evaluate the extent of influence of each factor on the measurement results. The test results from a SO3 analyzer showed that the measuring errors are mainly caused by the gas–liquid flow ratio, SO2 oxidation, and the side reactions of SO3. The error in the gas sampling rate is generally less than 13%. The isopropanol solution flow rate decreases 3% to 30% due to the volatilization of isopropanol, and accordingly, this will increase the apparent SO3 concentration. The amount of SO2 oxidation is linearly related to the SO2 concentration. The side reactions of SO3 reduce the selectivity of SO42- to nearly 73%. As sampling temperature increases from180 to 300°C, the selectivity of SO42- decreases from 73% to 50%. The presence of H2 O in the sample gas helps to reduce the measurement error by inhibiting the volatilization of the isopropanol and weakening side reactions. A formula was established to modify the displayed value, and the measurement error was reduced from 25%–54% to less than 15%.

Enriched Opportunistic Pathogens Revealed by Metagenomic Sequencing Hint Potential Linkages between Pharyngeal Microbiota and COVID-19

As a respiratory tract virus,SARS-CoV-2 infected people through contacting with the upper respiratory tract first.Previous studies indicated that microbiota could modulate immune response against pathogen infection.In the present study,we performed metagenomic sequencing of pharyngeal swabs from eleven patients with COVID-19 and eleven Non-COVID-19 patients who had similar symptoms such as fever and cough.Through metagenomic analysis of the above two groups and a healthy group from the public data,there are 6502 species identified in the samples.Specifically,the Pielou index indicated a lower evenness of the microbiota in the COVID-19 group than that in the Non-COVID-19 group.Combined with the linear discriminant analysis(LDA)and the generalized linear model,eighty-one bacterial species were found with increased abundance in the COVID-19 group,where 51 species were enriched more than 8 folds.The top three enriched genera were Streptococcus,Prevotella and Campylobacter containing some opportunistic pathogens.More interestingly,through experiments,we found that two Streptococcus strains,S.suis and S.agalactiae,could stimulate the expression of ACE2 of Vero cells in vitro,which may promote SARS-CoV-2 infection.Therefore,these enriched pathogens in the pharynxes of COVID-19 patients may involve in the virus-host interactions to affect SARS-CoV-2 infection and cause potential secondary bacterial infections through changing the expression of the viral receptor ACE2 and/or modulate the host’s immune system.

dCompaction： Speeding up Compaction of the LSM-Tree via Delayed Compaction

Key-value （KV） stores have become a backbone of large-scale applications in today＇s data centers. Write- optimized data structures like the Log-Structured Merge-tree （LSM-tree） and their variants are widely used in KV storage systems like BigTable and RocksDB. Conventional LSM-tree organizes KV items into multiple, successively larger components, and uses compaction to push KV items from one smaller component to another adjacent larger component until the KV items reach the largest component. Unfortunately, current compaction scheme incurs significant write amplification due to repeated KV item reads and writes, and then results in poor throughput. We propose a new compaction scheme, delayed compaction （dCompaction） that decreases write amplification, dCompaction postpones some compactions and gathers them into the following compaction. In this way, it avoids KV item reads and writes during compaction, and consequently improves the throughput of LSM-tree based KV stores. We implement dCompaction on RocksDB, and conduct extensive experiments. Validation using YCSB framework shows that compared with RocksDB, dCompaction has about 40% write performance improvements and also comparable read performance.

Coupling mechanism of activated carbon mixed with dust for flue gas desulfurization and denitrification

To clarify the effect of coking dust, sintering dust and fly ash on the activity of activated carbon for various industrial flue gas desulfurization and denitrification, the coupling mechanism of the mixed activated carbon and dust was investigated to provide theoretical reference for the stable operation. The results show that coking dust had 34% desulfurization efficiency and 10% denitrification efficiency;correspondingly, sintering dust and fly ash had no obvious desulfurization and denitrification activities. For the mixture of activated carbon and dust, the coking dust reduced the desulfurization and denitrification efficiencies by blocking the pores of activated carbon, and its inhibiting effect on activated carbon was larger than its own desulfurization and denitrification activity. The sintering dust also reduced the desulfurization efficiency on the activated carbon while enhancing the denitrification efficiency. Fly ash blocked the pores of activated carbon and reduced its reaction activity. The reaction activity of coking dust mainly came from the surface functional groups, similar to that of activated carbon. The reaction activity of sintering dust mainly came from the oxidative property of Fe_2O _3, which oxidized NO to NO_2 and promoted the fast selectively catalytic reduction(SCR) of NO to form N_2. Sintering dust was activated by the joint action of activated carbon, and both had a coupling function. Sintering dust enhanced the adsorption and oxidation of NO, and activated carbon further promoted the reduction of NO_x by NH_3;thus, the denitrification efficiency increased by 5%-7% on the activated carbon.

Luminescent single-molecule magnet of metallofullerene DyErScN@Ih-C80

Magneto-luminescent molecules have significant applications in data storage and quantum computing.However,design of these bi-functional molecules coupled with magnetic behavior and photoluminescence is still challenging.In this work,we report a metallofullerene DyErScN @In-C80 exhibiting single-molecule magnet (SMM) behavior and near-infrared emission.For DyErScN @Ih-C80,two functional lanthanide metal ions of Dy^3+(SMM function) and Er^3+(luminescent function) are integrated inside a fullerene cage using a trimetallic nitride template,and its structure has been unambiguously characterized by single-crystal X-ray diffraction.Magnetic measurements revealed that DyErScN @Ih-C80 behaves as a SMM with a blocking temperature up to 9 K resulting from the intramolecular magnetic interaction between Dy^3+ and Er^3+ ions.Moreover,DyErScN @In-C80 exhibits temperature-dependent near-infrared emission around 1.5 pm with multiple splitting peaks from Er^3+,which arises from the influence of Dy^3+ ion.This study provides a new strategy to synthesize new magneto-luminescent molecule materials.

SARS-CoV-2 Does Not Replicate in Aedes Mosquito Cells nor Present in Field-Caught Mosquitoes from Wuhan

Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARSCoV-2), the etiologic agent of COVID-19, is an enveloped,positive-sense single-stranded RNA virus that first discovered in December 2019 from a seafood market in Wuhan, China(Zhou et al. 2020).