分散固相萃取/高效液相色谱法测定鸡蛋中对位红与苏丹红染料残留

建立了一种分散固相萃取结合高效液相色谱法测定鸡蛋样品中对位红及苏丹红Ⅰ~Ⅳ染料残留的分析方法。样品经正己烷超声提取,二醇基(Diol)硅胶吸附富集,乙腈洗脱后在Phenomenex Luna C_(18)色谱柱(50 mm×2.0 mm,5μm)上以乙腈-水为流动相梯度洗脱,在500 nm波长处检测,外标法定量。5种染料在0.1~10.0 mg·L^(-1)范围具有良好的线性,相关系数均大于0.999,在低、中、高3个加标水平的平均回收率为81.2%~94.2%,相对标准偏差为3.4%~5.3%,检出限为0.018~0.030 mg·kg^(-1),定量下限为0.06~0.10 mg·kg^(-1)。建立的方法准确快速,可用于鸡蛋中对位红和苏丹红类染料残留的快速检测。

王阳明“知行合一”说在道德建设中之意义

王阳明不认同程朱"知先行后"的提法,主张"知行合一"说;此说是阳明38岁时,被贬谪到贵州的第二年(正德四年/1510),在贵阳书院讲学期间首度提出的。其中较重要且较完整的文本有两处:一处见于《传习录上·徐爱录》,约九百字的篇幅;一处见于《传习录中·答顾东桥书》,约千余字的篇幅。为求系统理解与诠释,本文依"为何有此说?""何为知?何为行?""何为知行合一?"三部分阐述,并结论出"知行合一"说在道德建设中之意义:第一在于反对任何一丝一毫的不善潜藏于心中,保证了道德实践动机的良善;第二在理论上驳斥"知易行难"和"知先行后"二说对道德笃行实践的可能妨碍,借此强调道德的行动、实践与道德认知的必然结合,深化了儒家重实践的道德理论。

“害怕与专业帮助人员亲近量表”在中美老人研究中的运用

该研究的主要目的是为了探讨不同文化背景下的人们不愿意寻求专业帮助的原因。本研究为中国和美国的社会工作人员、心理咨询师和心理学家提供参考,帮助他们更好地了解服务对象的心理抵触程度,从而根据具体情况采取对策,实施各种有效的干预措施。通过"害怕与专业帮助人员亲近量表"的运用,不仅可以使中国的社会工作者更有效地帮助服务对象,而且可以促进美国的专业人员更好地帮助在美华裔,并将增进中美两国进行跨文化的研究交流与合作。

从心学到心态学：阳明心学的当代转换

传统的复兴是当前一个非常重要的话题,如何从中国传统中找到应对当下各种问题的思想资源,已成为传统研究者面临的重要问题。从文化复兴的角度来说,阳明学在今天具有非常特殊的意义,无论从理论还是现实角度来说都是如此。本文立足于现代性转换的需要,从现代人的心态角度出发,试图从阳明心学中找到适合当代心态学需求的思想资源。如果可以实现从心学到心态学的有效转换,那么就意味着阳明心学所具有的当下的意义的实现。从这个角度来说,阳明心学对于今天,不仅具有理论上的意义,还具有十分重要的纠正现实的作用。

On Tilings of Quadrants and Rectangles and Rectangular Pattern

The problem of tiling rectangles by polyominoes generated large interest. A related one is the problem of tiling parallelograms by twisted polyominoes. Both problems are related with tilings of (skewed) quadrants by polyominoes. Indeed, if all tilings of a (skewed) quadrant by a tile set can be reduced to a tiling by congruent rectangles (parallelograms), this provides information about tilings of rectangles (parallelograms). We consider a class of tile sets in a square lattice appearing from arbitrary dissections of rectangles in two L-shaped polyominoes and from symmetries of these tiles about the first bisector. Only translations of the tiles are allowed in a tiling. If the sides of the dissected rectangle are coprime, we show the existence of tilings of all (skewed) quadrants that do not follow the rectangular (parallelogram) pattern. If one of the sides of the dissected rectangle is 2 and the other is odd, we also show tilings of rectangles by the tile set that do not follow the rectangular pattern. If one of the sides of the dissected rectangle is 2 and the other side is even, we show a new infinite family of tile sets that follows the rectangular pattern when tiling one of the quadrants. For this type of dis-section, we also show a new infinite family that does not follow the rectangular pattern when tiling rectangles. Finally, we investigate more general dissections of rectangles, with. Here we show infinite families of tile sets that follow the rectangular pattern for a quadrant and infinite families that do not follow the rectangular pattern for any quadrant. We also show, for infinite families of tile sets of this type, tilings of rectangles that do not follow the rectangular pattern.

Signed Tilings by Ribbon L n-Ominoes, n Even, via Gröbner Bases

Let Tn be the set of ribbon L-shaped n-ominoes for some n≥4 even, and let T+n be Tn with an extra 2 x 2 square. We investigate signed tilings of rectangles by Tn and T+n . We show that a rectangle has a signed tiling by Tn if and only if both sides of the rectangle are even and one of them is divisible by n, or if one of the sides is odd and the other side is divisible by . We also show that a rectangle has a signed tiling by T+n, n≥6 even, if and only if both sides of the rectangle are even, or if one of the sides is odd and the other side is divisible by . Our proofs are based on the exhibition of explicit GrÖbner bases for the ideals generated by polynomials associated to the tiling sets. In particular, we show that some of the regular tiling results in Nitica, V. (2015) Every tiling of the first quadrant by ribbon L n-ominoes follows the rectangular pattern. Open Journal of Discrete Mathematics, 5, 11-25, cannot be obtained from coloring invariants.

Signed Tilings by Ribbon L n-Ominoes, n Odd, via Gröbner Bases

We show that a rectangle can be signed tiled by ribbon L n-ominoes, n odd, if and only if it has a side divisible by n. A consequence of our technique, based on the exhibition of an explicit Gröbner basis, is that any k-inflated copy of the skewed L n-omino has a signed tiling by skewed L n-ominoes. We also discuss regular tilings by ribbon L n-ominoes, n odd, for rectangles and more general regions. We show that in this case obstructions appear that are not detected by signed tilings.

Evaluating Potential Vaccine Antigens in both the <i>Chlamydia trachomatis</i>and <i>Chlamydia muridarum</i>Intravaginal Mouse Challenge Models

Identifying relevant animal challenge models adds to the complexity of human vaccine development. Murine challenge models have been the most utilized animal model for Chlamydia trachomatis vaccine development. The question arises as to whether the C. trachomatis or C. muridarum pre-clinical model is optimal. We compared C. muridarum and C. trachomatis intravaginal challenge models in a combined total of seventy-five studies evaluating potential vaccine candidates. In 100% (42/42) of C. muridarum studies, mice immunized with Chlamydia elementary bodies (EB) demonstrated a significant reduction in urogenital bacterial shedding as measured by qPCR (p C. trachomatis studies. We have evaluated proposed vaccine antigens in both models and observed immunization with Chlamydia major outer membrane protein (MOMP) vaccine formulations to be protective (p C. trachomatis model, and immunization with PmpD p82 translocator domain was not protective in either model. We also observed in both models that depletion of CD4+ T-cells in MOMP-immunized mice resulted in diminished protective immunity but animals were still able to reduce the infection level. In contrast, mice immunized with live EBs by intraperitoneal route did not require CD4+ T-cells to resolve urogenital infection from intravaginal challenge in either model. Overall, we have found the C. muridarum model to be a more robust, reliable, and reproducible model for vaccine antigen discovery.

Tiling Rectangles with Gaps by Ribbon Right Trominoes

We show that the least number of cells (the gap number) one needs to take out from a rectangle with integer sides of length at least 2 in order to be tiled by ribbon right trominoes is less than or equal to 4. If the sides of the rectangle are of length at least 5, then the gap number is less than or equal to 3. We also show that for the family of rectangles that have nontrivial minimal number of gaps, with probability 1, the only obstructions to tiling appear from coloring invariants. This is in contrast to what happens for simply connected regions. For that class of regions Conway and Lagarias found a tiling invariant that does not follow from coloring.

A Small Correction to a Paper of Vandermonde

In this paper using elementary Galois Theory, we give a detailed explanation of the calculation of the radical expression for which was first discussed by Vandermonde decades before Galois and we point out and correct a minor correction in his work which was also observed by Lagrange.

Every Tiling of the First Quadrant by Ribbon <i>L n</i>-Ominoes Follows the Rectangular Pattern

Let and let be the set of four ribbon L-shaped n-ominoes. We study tiling problems for regions in a square lattice by . Our main result shows a remarkable property of this set of tiles: any tiling of the first quadrant by , n even, reduces to a tiling by and rectangles, each rectangle being covered by two ribbon L-shaped n-ominoes. An application of our result is the characterization of all rectangles that can be tiled by , n even: a rectangle can be tiled by , n even, if and only if both of its sides are even and at least one side is divisible by n. Another application is the existence of the local move property for an infinite family of sets of tiles: , n even, has the local move property for the class of rectangular regions with respect to the local moves that interchange a tiling of an square by n/2 vertical rectangles, with a tiling by n/2 horizontal rectangles, each vertical/horizontal rectangle being covered by two ribbon L-shaped n-ominoes. We show that none of these results are valid for any odd n. The rectangular pattern of a tiling of the first quadrant persists if we add an extra tile to , n even. A rectangle can be tiled by the larger set of tiles if and only if it has both sides even. We also show that our main result implies that a skewed L-shaped n-omino, n even, is not a replicating tile of order k2 for any odd k.

Selection of Reference Genes in Equine White Blood Cells for Real Time PCR Normalization Following Extracorporeal Shock Wave Therapy

Selection of proper reference genes (RGs) is an essential step needed for accurate normalization of results from genomic studies. Expression of RGs is regulated by many factors such as species, age, gender, type of tissue, the presence of disease, and the administration of therapeutic treatment. The aim of the present study was to identify optimal RGs in a set of blood samples collected at different time points (0, 24, 48, 72 h) from horses following administration of extracorporeal shock wave therapy (ESWT). The mRNA expression of twelve RGs: HPRT1, ACTB, HSP90A, SDHA, GUSB, B2M, UBC, NONO, TBP, H6PD, RPL32, GAPDH was determined using real time quantitative polymerase chain reaction (qPCR). An SAS program developed on the algorithm of geNorm, SASqPCR, was used to determine stability of the expression and the number of optimal RGs. The results showed that the range of quantification cycle (Cq) values of the evaluated genes varied between 17 and 26 cycles, and that one optimal RG, ACTB, was sufficient for normalization of gene expression. Results of stability of expression demonstrated that ACTB was the optimal choice for all the samples studied. Notably, in samples collected at 72 h post ESWT, TBP showed a significant change in the expression level, and was not suitable for use as a RG. These results substantiate the importance of validating and selecting an appropriate RG.

Revisiting a Tiling Hierarchy (II)

In a recent paper, we revisited Golomb’s hierarchy for tiling capabilities of finite sets of polyominoes. We considered the case when only translations are allowed for the tiles. In this classification, for several levels in Golomb’s hierarchy, more types appear. We showed that there is no general relationship among tiling capabilities for types corresponding to same level. Then we found the relationships from Golomb’s hierarchy that remain valid in this setup and found those that fail. As a consequence we discovered two alternative tiling hierarchies. The goal of this note is to study the validity of all implications in these new tiling hierarchies if one replaces the simply connected regions by deficient ones. We show that almost all of them fail. If one refines the hierarchy for tile sets that tile rectangles and for deficient regions then most of the implications of tiling capabilities can be recovered.

Infinite Parametric Families of Irreducible Polynomials with a Prescribed Number of Complex Roots

In this note, for any pair of natural numbers (n,k), n&#8805;3, k&#8805;1, and 2k&#60;n, we construct an infinite family of irreducible polynomials of degree n, with integer coefficients, that has exactly n-2k?complex non-real roots if n is even and has exactly n-2k-1?complex non-real roots if n is odd. Our work generalizes a technical result of R. Bauer, presented in the classical monograph “Basic Algebra” of N. Jacobson. It is used there to construct polynomials with Galois groups, the symmetric group. Bauer’s result covers the case k=1?and n odd prime.

Irreducible Polynomials in &#918;[x] That Are Reducible Modulo All Primes

The polynomial x4+1 is irreducible in &#918;[x] but is locally reducible, that is, it factors modulo p for all primes p. In this paper we investigate this phenomenon and prove that for any composite natural number N there are monic irreducible polynomials in &#918;[x] which are reducible modulo every prime.

The Tilings of Deficient Squares by Ribbon <i>L</i>-Tetrominoes Are Diagonally Cracked

We consider tilings of deficient rectangles by the set T4 of ribbon L-tetro-minoes. A tiling exists if and only if the rectangle is a square of odd side. The missing cell has to be on the main NW-SE diagonal, in an odd position if the square is (4m+1)×(4m+1) and in an even position if the square is (4m+3)×(4m+3). The majority of the tiles in a tiling follow the rectangular pattern, that is, are paired and each pair tiles a 2×4 rectangle. The tiles in an irregular position together with the missing cell form a NW-SE diagonal crack. The crack is located in a thin region symmetric about the diagonal, made out of a sequence of 3×3 squares that overlap over one of the corner cells. The crack divides the square in two parts of equal area. The number of tilings of a (4m+1)×(4m+1) deficient square by T4? is equal to the number of tilings by dominoes of a 2m×2m square. The number of tilings of a (4m+3)×(4m+3) deficient square by T4? is twice the number of tilings by dominoes of a (2m+1)×(2m+1)?deficient square, with the missing cell placed on the main diagonal. In both cases the counting is realized by an explicit function which is a bijection in the first case and a double cover in the second. If an extra 2×2 tile is added to T4 , we call the new tile set?T+<sub style="margin-left:-6px;">4. A tiling of a deficient rectangle by T+4 exists if and only if the rectangle is a square of odd side. The missing cell has to be on the main NW-SE diagonal, in an odd position if the square is (4m+1)×(4m+1) and in an even position if the square is (4m+3)×(4m+3). The majority of the tiles in a tiling follow the rectangular pattern, that is, are either paired tetrominoes and each pair tiles a 2×4 rectangle, or are 2×2 squares. The tiles in an irregular position together with the missing cell form a NW-SE diagonal crack. The crack is located in a thin region symmetric about the diagonal, made out of a sequence of 3×3 squares that overlap over one of the corner cells. The number of tilings of a (4m+1)×(4m+1) deficient square by T+4 is greater than the number of tilings by dominoes and monomers of a 2m×2m square. The number of tilings of a (4m+3)×(4m+3) deficient square by T+4 is greater than twice the number of tilings by dominoes and monomers of a (2m+1)×(2m+1) deficient square, with the missing cell placed on the main diagonal. We also consider tilings by T4? and T+4 of other significant deficient regions. In particular we show that a deficient first quadrant, a deficient half strip, a deficient strip or a deficient bent strip cannot be tiled by T+4. Therefore T4? and T+4 give examples of tile sets that tile deficient rectangles but do not tile any deficient first quadrant, any deficient half strip, any deficient bent strip or any deficient strip.

On Tate’s Proof of a Theorem of Dedekind

In this note we give a complete proof of a theorem of Dedekind.

Doping Control Analysis of 16 Non-Steroidal Anti-Inflammatory Drugs in Equine Plasma Using Liquid Chromatography-Tandem Mass Spectrometry

Non-steroidal anti-inflammatory drugs (NSAIDs) are classified as Class 4 agents by the Association of Racing Commissioners International and are banned in racehorses during competition in Pennsylvania (PA). To control the abuse of these agents in racehorses competing in PA, a forensic method for screening and confirmation of the presence of these agents is needed. Equine plasma (0.5 mL) was acidified with 75 μL 1M H3PO4 to increase recovery of the analytes by liquid-liquid extraction using methyl tert-butyl ether (MTBE). Extracted analytes were separated by reversed-phase liquid chromatography using a C8 column under gradient condition. All 16 analytes were detected, quantified and confirmed using a triple quadrupole tandem mass spectrometry with selected reaction monitoring (SRM) in both negative and positive electrospray ionization modes. The limit of detection, quantification and confirmation of the analytes were 1.0 - 5.0 ng/mL, 1.0 - 5.0 ng/mL and 1.0 - 20 ng/mL, respectively. The linear dynamic range of quantification was 5.0 - 200 ng/mL. The method is routinely used in anti-doping analysis to control the abuse of NSAIDs in racehorses competing in PA.

Infinite Sets of Solutions and Almost Solutions of the Equation <i>N</i>&sdot;<i>M</i>= reversal(<i>N</i>&sdot;<i>M</i>)

Motivated by their intrinsic interest and by applications to the study of numeric palindromes and other sequences of integers, we discover infinite sets of solutions and almost solutions of the equation N?&sdot;?M=reversal (N?&sdot;M). Most of our results are valid in a general numeration base.

Infinite Sets of Solutions and Almost Solutions of the Equation <i>N</i>⋅<i>M</i>= <i>reversal</i>(<i>N</i>⋅<i>M</i>) II

Motivated by their intrinsic interest and by applications to the study of numeric palindromes and other sequences of integers, we discover a method for producing infinite sets of solutions and almost solutions of the equation N⋅M = reversal (N⋅M), our results are valid in a general numeration base b > 2.