PBL教学法在消化内科双语教学见习中的应用

目的:探讨PBL教学方法在七年制医学生消化内科双语教学见习中的应用效果.方法:选择在我院实习的首都医科大学2007级及2008级七年制临床医学系及儿科系学生,分为实验组和对照组,对两组学生采取不同的教学方法,比较教学效果.结果:实验组学生理论及病例书写成绩均优于对照组学生;并在提高学习兴趣、活跃课堂气氛;提高搜集资料、阅读文献能力;提高互相合作及团队精神方面PBL教学法均优于传统方法.结论:PBL式双语教学可以提高教学效果和学生的素质,值得我们不断探索和研究.     

PBL教学法在肾科临床见习中的应用

目的:探讨以问题为基础的教学法(Problem Based learning,PBL)在肾科临床见习教学中的应用价值。方法:首都医科大学宣武医院63名参加内科学肾脏病临床见习的七年制学生随机分成对照组和观察组,对照组采用传统的基于授课的教学法进行教学,观察组用PBL教学法进行教学,比较2组学习成绩的差异;向学生发放问卷调查,调查学生对2种教学方法的认可程度。结果:2组学生的填空题、选择题及简答题成绩比较无显著性差异(P0.05);观察组病例分析题成绩好于对照组(P=0.001);培养临床思维、激发学习兴趣方面和自主学习能力方面PBL教学法优于传统教学法(P0.01)。结论:PBL教学法有助于学生临床思维和临床技能的培养,从而使教学质量得到提高。     

PBL教学法联合PACS系统在医学影像学教学中的应用

目的:探讨采用PBL和PACS相结合的教学模式在影像学实习教学中的应用效果。方法:对我院2010级临床本科生40人采用传统教学法授课,另40人采用PBL和PACS相结合的教学法授课。课程结束后以考试成绩作为教学效果的评价指标,评价两种教学方法的教学效果;以调查问卷的方法评价学生对两种教学方法的感兴趣程度,并对结果进行统计学分析。结果:我们的研究结果显示,采用PBL和PACS相结合的方法进行教学的学生与传统教学法相比,理论考试成绩有所提高,但缺乏统计学意义(p0.05),病例分析成绩显著提高,差异有统计学意义(P0.05)。问卷调查显示,PBL和PACS结合的教学方法更受同学欢迎,更能培养学生的自学能力和团队合作能力(P0.05)。结论:采用PBL和PACS相结合的教学方法,有助于提高学生的学习兴趣,提高学习成绩,值得在教学中应用。     

情景教学结合CBL教学在七年制急诊医学实习中的应用

目的:研究情景教学结合以案例为基础的教学(Case-Based learning,CBL)在七年制急诊医学实习中的应用效果。方法:七年制见习学生随机分为观察组和对照组,观察组应用情景教学结合CBL教学,对照组应用传统教学,实习结束时进行分别进行理论和技能考核,理论考试题型包括填空、名词解释和病例分析,技能考核为心肺复苏,比较2组成绩的差别。对观察组进行问卷调查,研究观察组对情景教学结合CBL教学的看法。结果:观察组填空、名词解释成绩与对照组无明显差异(P0.05),病例分析和技能成绩显著高于对照组(P0.01);100%的学生喜欢情景教学结合CBL教学法,96.7%认为该教学法可以提高学生的综合能力。结论:情景教学结合CBL教学法可以提高七年制学生的学习成绩和综合能力,增加学习兴趣。     

PBL教学法在肾科临床见习中的应用

目的：探讨以问题为基础的教学法（Problem Based learning,PBL）在肾科临床见习教学中的应用价值。方法：首都医科大学宣武医院63名参加内科学肾脏病临床见习的七年制学生随机分成对照组和观察组,对照组采用传统的基于授课的教学法进行教学,观察组用PBL教学法进行教学,比较2组学习成绩的差异;向学生发放问卷调查,调查学生对2种教学方法的认可程度。结果：2组学生的填空题、选择题及简答题成绩比较无显著性差异（P〉0.05）;观察组病例分析题成绩好于对照组（P=0.001）;培养临床思维、激发学习兴趣方面和自主学习能力方面PBL教学法优于传统教学法（P〈0.01）。结论：PBL教学法有助于学生临床思维和临床技能的培养,从而使教学质量得到提高。     

PBL与LBL结合在血管外科临床见习教学中的应用

目的:为提高临床血管外科的教学质量,我们在临床见习中尝试将PBL教学模式与LBL传统教学模式相结合,研究PBL与LBL教学法相结合新的教学方法在临床血管外科教学中的作用。方法:选取在我院参加实习活动的临床医学系学生60名,随机分为LBL组与LBL+PBL组。其中LBL组采用传统教学模式,而LBL+PBL组则采用传统教学与问题导向型教学模式相结合的双轨教学法。课程结束后,对比两组学生的专业知识笔试成绩和临床操作技能测试成绩,评价两种教学模式的作用及意义。结果:PBL+LBL组学生的专业知识笔试成绩和临床操作技能成绩均显著优于LBL组,差异有统计学意义(P0.05)。结论:PBL与LBL教学法相结合的双规教学模式对血管外科的临床见习教学具有积极的意义,不但可以锻炼学生的临床思维能力,培养学生的综合素质,而且有利于提高临床教学的质量,该教学模式值得在医学院校实习教学中推广应用。     

PBL联合LBL双轨教学模式在医学留学生生物化学教学中的实践应用

为了满足医学院校生物化学教学国际化的需求,提高医学留学生生物化学教学水平,探讨PBL(problem-based learning)联合LBL(lecture-based learning)双轨教学模式的优越性,我们将本科层次的医学留学生按自然分配班级分为传统LBL教学对照组和PBL联合LBL双轨教学实验组;采用期末考试成绩量化和问卷调查相结合的方式,综合评价PBL联合LBL双轨教学法的教学效果。经统计分析,实验组学生成绩显著高于对照组学生成绩,90%以上的学生认为PBL联合LBL双轨教学模式能激发学习兴趣,提高自身多重能力。结果表明,PBL联合LBL双轨教学模式对医学留学生的生物化学的教学效果明显优于传统LBL教学。     

临床专升本急救医学临床见习方法的研究

目的:探讨PBL(以问题为中心的教学法)结合计算机模拟教学在临床专升本急救医学临床见习中的教学效果.方法:对我院80名临床专升本学生急救医学临床见习采用PBL结合计算机模拟教学的方法,设计急救医学中常见的多发伤、急性脑血管病与心肺复苏病例,比较见习前后的教学效果;发放调查问卷,调查学生对教学方法的态度.结果:应用PBL结合计算机模拟教学见习前后的多发伤分别为68.4±8.1和85.7±7.6;急性脑血管病71.4±8.2和83.2±7.6;心肺复苏理论72.6±8.7和87.3±9.2;和心肺复苏技能成绩70.2±8.6和89.5±9.4,(P<0.05);98.7%的学生喜欢PBL结合计算机模拟教学法.97.5%认为PBL结合计算机模拟教学法加深了学习能力和实践能力.结论:在临床专升本急救医学临床见习中采用PBL结合计算机模拟教学可以提高学生的学习成绩,促进实践能力和团队精神的培养.     

LBL结合PBL在物理诊断教学过程中的初步探索

目的:比较传统教学模式和问题教学法及二者结合教学法的不同优劣势,找出物理诊断学最佳教学方法。传统教学模式采用授课为主的教学法(lecture based learning,LBL),单单强调了教师的重要性,而忽视学生的主观能动性,不利于调动和培养学生自学和灵活运用所学知识的能力。问题教学法(Problem-based learning,PBL),其强调学生自身的主观能动性,弱化了教师在教学中的主体地位,学生有偏离教学主线的风险。因而如果将LBL与PBL有机结合在一起,将可能有利于提高学生的学习效率和学习效果。方法:选取97名全科医学本科学员,在物理诊断课程教学过程中,采用完全随机的方法分为2组,采用LBL教学方法组48人,采用LBL结合PBL教学方法组49人,通过分别对理论、实践分层打分,确定优秀、合格、不合格的比率,采用Mann-Whitney U检验最终评定2组教学方法的授课效果。结果:在理论考试中,2组学员在优秀、合格、不合格的分层评定上均无明显差异(P0.05),而在实践考核中,LBL+PBL组学员成绩在优秀这一分层评定中,优于LBL组,差异具有统计学意义(P0.05)。结论:LBL和PBL教学方法结合应用于物理诊断教学中,符合物理诊断教学的特点,更容易被学生接受,对于知识的识记和应用更有好处,从而更利于培养高素质医学人才,值得在物理诊断教学中进一步推广。     

PBL+LBL教学模式在留学生医学微生物学教学中的实践

由于留学生的特殊性导致他们对传统教学模式的不适应,医学微生物学的课程特点使留学生学习掌握相关知识较困难,有必要探索好的教学方法,提高教学质量。我国传统的LBL教学模式和国际上流行的PBL教学模式各有优缺点,我们融合PBL和LBL的优点,互补其缺点,对留学生医学微生物学课程采取PBL+LBL教学模式,既发挥PBL教学法打破学科界限,容易调动学生学习积极性,注重培养学生自主学习和团结协作能力的特点,又结合LBL教学法传授知识系统、完整,培养学生基础理论扎实等优势。教学实践证明,PBL+LBL教学法运用于留学生医学微生物学教学,能激发留学生学习兴趣,在增强留学生对医学微生物学基础理论和基本技能掌握的同时,培养留学生知识整合的能力及创新思维的医学综合能力,提高教学质量。     

Role of tfdC(I)D(I)E(I)F(I) and tfdD(II)C(II)E(II)F(II) gene modules in catabolism of 3-chlorobenzoate by Ralstonia eutropha JMP134(pJP4)

The enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow Ralstonia eutropha JMP134(pJP4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-CB). There are two gene modules located in plasmid pJP4, tfdC(I)D(I)E(I)F(I) (module I) and tfdD(II)C(II)E(II)F(II) (module II), putatively encoding these enzymes. To assess the role of both tfd modules in the degradation of chloroaromatics, each module was cloned into the medium-copy-number plasmid vector pBBR1MCS-2 under the control of the tfdR regulatory gene. These constructs were introduced into R. eutropha JMP222 (a JMP134 derivative lacking pJP4) and Pseudomonas putida KT2442, two strains able to transform 3-CB into chlorocatechols. Specific activities in cell extracts of chlorocatechol-1,2-dioxygenase (tfdC), chloromuconate cycloisomerase (tfdD), and dienelactone hydrolase (tfdE) were 2 to 50 times higher for microorganisms containing module I compared to those containing module II. In contrast, a significantly (50-fold) higher activity of maleylacetate reductase (tfdF) was observed in cell extracts of microorganisms containing module II compared to module I. The R. eutropha JMP222 derivative containing tfdR-tfdC(I)D(I)E(I)F(I) grew four times faster in liquid cultures with 3-CB as a sole carbon and energy source than in cultures containing tfdR-tfdD(II)C(II)E(II)F(II). In the case of P. putida KT2442, only the derivative containing module I was able to grow in liquid cultures of 3-CB. These results indicate that efficient degradation of 3-CB by R. eutropha JMP134(pJP4) requires the two tfd modules such that TfdCDE is likely supplied primarily by module I, while TfdF is likely supplied by module II.     

Synthesis and luminescence properties of a blue-emitting Sr(3.5) Y(6.5) O(2) (PO(4) )(1.5) (SiO(4) )(4.5) :Eu(2+) phosphor

A novel blue‐emitting Sr_3.5Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5:Eu²⁺ phosphor was synthesized via a solid‐state reaction. Powder X‐ray diffraction (XRD) analysis demonstrated that the Sr_3.5Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5 host had a hexagonal crystal structure in the space group P6₃/m and unit cell parameters a = 9.418 Å, c = 6.900 Å. The as‐prepared phosphor showed a blue emission and all the main emission peaks were located at around 466 nm for different excitation wavelengths of 297, 333 and 391 nm. The temperature dependence of the photoluminescence property was investigated in the range 20–250 °C, and the emission intensity decreased to 71% of the initial value at room temperature on increasing the temperature to 150 °C. According to the classical theory of fluorescent thermal quenching, the activation energy (ΔE) for the thermal quenching luminescence of the as‐prepared Sr_3.45Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5:0.05Eu²⁺ phosphor was determined to be 0.20 eV. Copyright © 2011 John Wiley & Sons, Ltd.     

Biology of Bactrocera (Zeugodacus) tau (Walker) (Diptera: Tephritidae)

The biology of the fruit fly Bactrocera tau, an important horticultural pest, was studied under laboratory conditions at 25°C and 60–70% relative humidity on Cucurbita maxima. The duration of mating averaged 408.03 ± 235.93 min. After mating, the female fly had a preoviposition period of 11.7 ± 4.49 days. The oviposition rate was 9.9 ± 8.50 eggs and fecundity was 464.6 ± 67.98 eggs/female. Eggs were elliptical, smooth and shiny white, turning darker as hatching approached, and measured 1.30 ± 0.07 mm × 0.24 ± 0.04 mm. The chorion has polygonal microsculpturing and is species-specific with polygonal walls. The egg period lasts for 1.3 ± 0.41 days. The duration of the larval period is 1.2 ± 0.42, 1.7 ± 0.48 and 4.0 ± 0.94 days for first, second and third instars, respectively. Pupation occurs in the sand or soil and pupal periods are 7.0 ± 0.47 days. The life cycle from egg to adult was completed in 14.2 ± 1.69 days; the longevity of mated females and males was 130.33 ± 14.18 and 104.66 ± 31.21 days, respectively. At least two to three generations were observed from June 2008 to June 2009.     

Collagen-like triple helix formation of synthetic (Pro-Pro-Gly)10 analogues: (4(S)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10, (4(R)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10 and (4(S)-fluoroprolyl-4(R)-fluoroprolyl-Gly)10.

For the rational design of a stable collagen triple helix according to the conventional rule that the pyrrolidine puckerings of Pro, 4-hydroxyproline (Hyp) and 4-fluoroproline (fPro) should be down at the X-position and up at the Y-position in the X-Y-Gly repeated sequence for enhancing the triple helix propensities of collagen model peptides, a series of peptides were prepared in which X- and Y-positions were altogether occupied by Hyp(R), Hyp(S), fPro(R) or fPro(S). Contrary to our presumption that inducing the X-Y residues to adopt a down-up conformation would result in an increase in the thermal stability of peptides, the triple helices of (Hyp(S)-Hyp(R)-Gly)(10) and (fPro(S)-fPro(R)-Gly)(10) were less stable than those of (Pro-Hyp(R)-Gly)(10) and (Pro-fPro(R)-Gly)(10), respectively. As reported by B?chinger's and Zagari's groups, (Hyp(R)-Hyp(R)-Gly)(10) which could have an up-up conformation unfavorable for the triple helix, formed a triple helix that has a high thermal stability close to that of (Pro-Hyp(R)-Gly)(10). These results clearly show that the empirical rule based on the conformational preference of pyrrolidine ring at each of X and Y residues should not be regarded as still valid, at least for predicting the stability of collagen models in which both X and Y residues have electronegative groups at the 4-position.     

Archaeobotany of capers (Capparis) (Capparaceae)

The origins of capers, their use and cultivation are discussed. Capers seeds and charcoal are often recovered from archaeological sites of the Mediterranean and West Asia. These are referred to as C. Spinosa L. This is mostly a group of cultivars restricted to localities surrounding the Western Mediterranean and some places in the Eastern Mediterranean. Identification of the findings is discussed in terms of seed morphology, present distribution and ancient uses of C. aegyptia Lam., C. sicula Veill., C. cartilaginea Decne, C. orientalis Veill., C. decidua (Forssk.) Edgew. and other species. Citations of Capparis in early Rabbinic, Mesopotamian and Greco-Roman texts are presented. Received June 3, 2002 / Accepted October 8, 2002 Correspondence to: D. Rivera     

The helix-coil transitions of poly (dA)-poly (dT) and poly (dA-dT)-poly (dA-dT)

Helix–coil transition curves are calculated for poly (dA) poly(dT) and poly (dA-dT) poly (dA-dT) using the integral equation approach of Goel and Montroll.⁵ The transitions are described by the loop entropy model with the exponent of the loop entropy factor, k, remaining an arbitrary constant. The theoretical calculations are compared with experimental transition curves of the two polymers. Results indicate that the stacking energies for these two polymers differ by about 1 kcal/mole of base pairs. Also, a fit between theory and experiment was not possible for k > 1.70.     

Induction of in vitro flowering in Dendrobium Madame Thong-In (Orchidaceae) seedlings is associated with increase in endogenous N(6)-(Delta (2)-isopentenyl)-adenine (iP) and N (6)-(Delta (2)-isopentenyl)-adenosine (iPA) levels

We analysed the endogenous cytokinin levels of Dendrobium Madame Thong-In seedlings grown in vitro during vegetative and flowering-inductive periods. HPLC was used to fractionate the extracts and radioimmunoassay (RIA) was used for assay of zeatin (Z), dihydrozeatin (DZ), N(6)-(Delta(2)-isopentenyl)-adenine (iP) and their derivatives. Coconut water used in experiments was found to contain high level (>136 pmol ml(-1)) of zeatin riboside (ZR). Protocorms and seedlings cultured in medium with coconut water were found to contain 0.5-3.9 pmol g(-1) FW of the cytokinins analysed. Seedlings (1.0-1.5 cm) cultured in flowering-inductive liquid medium containing 6-benzyladenine (BA, 4.4 muM) and coconut water (CW, 15%) contained up to 200 and 133 pmol g(-1) FW of iP and iPA, respectively. These levels were significantly higher than all other cytokinins analysed in seedlings of the same stage and were about 80- to 150-folds higher than seedlings cultured in non-inductive medium. During the transitional (vegetative to reproductive) stage, the endogenous levels of iP (178 pmol g(-1) FW) and iPA (63 pmol g(-1) FW) were also significantly higher than cytokinins in the zeatine (Z) and dihydrozeatin (DZ) families in the same seedlings. Seedlings that grew on inductive medium but remained vegetative contained lower levels of iPA. The importance of the profiles of iP and its derivatives in induction of in vitro flowering of D. Madame Thong-In is discussed.     

Spectroscopic investigations of Er(3+) :CdO-Bi(2) O(3) -B(2) O(3) glasses

This article reports on the optical properties of Er³⁺ ions doped CdO–Bi₂O₃–B₂O₃ (CdBiB) glasses. The materials were characterized by optical absorption and emission spectra. By using Judd–Ofelt theory, the intensity parameters Ω_λ (λ = 2, 4, 6) and also oscillatory strengths were calculated from the absorption spectra. The results were used to compute the radiative properties of Er³⁺:CdBiB glasses. The concentration quenching and energy transfer from Yb³⁺–Er³⁺ were explained. The stimulated emission cross‐section, full width at half maximum (FWHM) and FWHM × values are also calculated for all the Er³⁺:CdBiB glasses. Copyright © 2011 John Wiley & Sons, Ltd.     

Copper (II) and cobalt (II) complexes of chiral tetrathiafulvalene-oxazoline (TTF-OX) and tetrathiafulvalene-thiomethyl-oxazoline (TTF-SMe-OX) derivatives

Synthesis and single crystal X-ray structures of the first paramagnetic transition metal complexes containing chiral ethylenedithio-tetrathiafulvalene-oxazoline (EDT-TTF-OX) 1a-c and ethylenedithio-tetrathiafulvalene-thiomethyloxazoline 2 (EDT-TTF-(SMe)OX) ligands based on copper (II) and cobalt (II) are described. The racemic [EDT-TTF-OX][Cu(hfac)₂] complex 3a crystallizes in the triclinic centrosymmetric space group , whereas the enantiopure counterparts 3b-c crystallize in the triclinic non-centrosymmetric space group P1. Cu(II) adopts a distorted square pyramidal coordination geometry, a much weaker Cu?S_TTF interaction also being identified. The same coordination pattern around Cu(II) is observed in the complex [(rac)-EDT-TTF-(SMe)OX][Cu(hfac)₂] (4) in spite of the bidentate nature of the redox active ligand. DFT theoretical calculations afforded two equilibrium configurations for a corresponding model complex, in which the metal centre establishes secondary coordination either with one S_TTF or with the SMe group. The same ligand coordinates the cobalt (II) to afford the octahedral complex [(rac)-EDT-TTF-(SMe)OX][Co(hfac)₂] (5). In all these novel complexes, the paramagnetic centres are structurally and magnetically isolated. Cyclic voltammetry measurements show the stability of the radical cation species.