A Well-Balanced Positivity-Preserving Quasi-Lagrange Moving Mesh DG Method for the Shallow Water Equations

A high-order, well-balanced, positivity-preserving quasi-Lagrange moving mesh DG method is presented for the shallow water equations with non-flat bottom topography. The well-balance property is crucial to the ability of a scheme to simulate perturbation waves over the lake-at-rest steady state such as waves on a lake or tsunami waves in the deep ocean. The method combines a quasi-Lagrange moving mesh DG method, a hydrostatic reconstruction technique, and a change of unknown variables. The strategies in the use of slope limiting, positivity-preservation limiting, and change of variables to ensure the well-balance and positivity-preserving properties are discussed. Compared to rezoning-type methods, the current method treats mesh movement continuously in time and has the advantages that it does not need to interpolate flow variables from the old mesh to the new one and places no constraint for the choice of a update scheme for the bottom topography on the new mesh. A selection of one- and two-dimensional examples are presented to demonstrate the well-balance property, positivity preservation, and high-order accuracy of the method and its ability to adapt the mesh according to features in the flow and bottom topography.     

Synthesis of 13C-labeled parabens from isotopically enriched phenols using the Houben–Hoesch reaction

Parabens are antimicrobial additives found in a wide array of consumer products. However, the halogenated compounds formed from parabens during wastewater disinfection are a potential environmental concern. In order to identify these transformation products and investigate their mechanism of formation, a synthetic route to ethyl parabens labeled with the stable isotope carbon-13 at specific positions within the benzene ring was developed. This efficient two-step procedure starts from commercially available ¹³C-labeled phenols and involves (1) initial acylation of the phenol via a Houben–Hoesch reaction with trichloroacetonitrile followed by (2) a modified haloform reaction of the resulting trichloromethyl ketone to afford the corresponding ¹³C-labeled ethyl parabens in 65%–80% overall yield. The scope of the modified haloform reaction was also investigated, allowing for the synthesis of other parabens derived from primary or secondary alcohols, including ¹³C- and deuterium-labeled esters. In addition, 4-hydroxybenzoic acid can be formed directly from the common trichloromethyl ketone intermediate upon treatment with lithium hydroxide. This protocol complements existing methods for preparing ¹³C-labeled paraben derivatives and offers the specific advantages of exhibiting complete regioselectivity in the Houben–Hoesch reaction (to form the para-disubstituted product) and avoiding the need for protecting groups in the modified haloform reaction that forms the paraben esters.     

《邵氏医案》从血辨治痛经浅析

[目的]分析总结浙江近代著名临床医家邵兰荪治疗痛经的经验,以期为临床治疗提供借鉴。[方法]通过研读裘吉生编《邵氏医案》,筛选出其中治疗痛经的医案十余则,并结合邵氏在妇科方面的学术思想,进一步分析其辨证立法遣方特色,从而总结邵氏治疗痛经的临证经验。[结果]邵氏治疗痛经多从血辨治,且分虚实两端,其中属虚者血虚内热用益母胜金丹养血清热、活血止痛,血虚肝风治以养血柔肝、息风止痛;属实者水结血瘀用五苓散利水散瘀、行气止痛,气阻血滞治从行气活血、调经止痛。[结论]在治疗妇人痛经方面,邵氏辨治遣方确有独特经验,这些经验可为中医药治疗此类疾病拓宽诊治思路,有助于提高临床疗效。     

Tuberculosis and other chronic morbidity profile of sewage workers of Delhi

Background

Sewage management is hazardous due to chronic exposure to chemical gases, bioaerosols and micro-organisms through inhalation; accidental oral intake and penetration through skin or mucous membranes through injuries or breech in personal protective equipment. While there has been some research on isolated infections and multisystem symptom profiling of sewage workers, there is little research on the burden of chronic illnesses like Tuberculosis and Non Communicable Diseases (NCDs).

针刺咽部腧穴治疗脑梗死后真性延髓麻痹:随机对照研究

目的:比较针刺患侧与针刺双侧咽部腧穴治疗脑梗死后真性延髓麻痹的临床疗效。方法:将66例脑梗死后真性延髓麻痹患者随机分为单侧组和双侧组,每组33例,最后每组各有1例脱落。两组患者在常规药物和电项针治疗的基础上,单侧组针刺患侧的吞咽、发音和治反流穴,双侧组针刺双侧吞咽、发音和治反流穴。每天1次,每周连续针刺6 d,休息1 d,治疗21 d后评定临床疗效。采用吞咽困难分级量表、洼田饮水试验和GRBAS分级评价两组患者治疗前后的吞咽和构音情况。结果:治疗21 d后,两组患者吞咽困难分级量表评分均提高(均P<0.01),且单侧组改善程度大于双侧组(P<0.01);两组患者GRBAS分级、洼田饮水试验情况均改善(均P<0.01),且单侧组改善程度大于双侧组(P<0.05,P<0.01)。结论:针刺患侧咽部腧穴治疗脑梗死后真性延髓麻痹较针刺双侧咽部腧穴疗效更优。