Design and construction of a 110 W green laser for medical application

In this paper, the design and the construction of a high-power side-diode-pumped Nd:YAG solid-state laser at repetition rates of 6 and 10 kHz has been presented. Second harmonic of the Nd:YAG laser with green light at 532 nm, with an average power of 111.5 W at 10 kHz repetition rate, and with 90 ns pulse duration, has been obtained by the nonlinear crystal of KTP with 59% conversion efficiency and 12% diode-to-green optical–optical efficiency in the linear resonator. Beam spot size and divergence is 4 mm and 8 mrad, respectively. The laser stability is about 97%. As a medical application of this laser, investigation of degree of effectiveness and penetration depth of laser on adenomas of resected prostate after open prostatectomy has been done.     

不同月经周期乳腺增生的超声图像分析

本文对不同月经周期乳腺增生的超声图像特征进行了分析.研究对象为选取2017年6月～2019年6月本院乳腺增生患者102例,所有患者均于不同月经周期(月经期、增殖期、分泌期)给予彩色多普勒超声检查,并检测性激素[雌二醇(E2)、孕酮(P)],分析不同月经周期乳腺增生的超声图像特征.结果 显示,102例乳腺增生患者中,彩色...     

l-Proline as an efficicent catalyst for the multi-component synthesis of 6-amino-4-alkyl/aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles in water

An efficient four-component synthesis of 6-amino-4-alkyl/aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles involving ethyl acetoacetate, hydrazine hydrate, malononitrile, and various aldehydes using l-proline (10 mol %) in water under mild reaction condition in excellent yields is established. A comparative study of l-proline with γ-alumina, basic alumina, and KF-alumina was also carried out. The generality and functional tolerance of this convergent and environmentally benign method is demonstrated.     

Expeditious synthesis of indolizine derivatives via iodine mediated 5-endo-dig cyclization

Iodine-mediated 5-endo-dig cyclization of propargylic esters 2 at room temperature proceeded smoothly to give highly functionalized indolizines 3 in excellent yields. A pyridine group was employed as a nucleophilic partner in this facile process for the first time.     

对改革开放中多样价值取向的思考

多样价值取向的产生是全球一体化所引起的剧烈碰撞中的必然现象,它代表着社会不同阶层、集团的经济利益、政治诉求和意识形态倾向。尽管多样价值取向会给社会带来一定的消极影响,但是也有其存在的合理性。总结历史经验教训,探求出一条以核心价值体系引领多样价值取向的道路,可以有效实现良性共存,共创和谐社会。     

Lithium heptadecafluorooctanesulfonate catalyzed Mannich-type and aza-Diels-Alder reactions in supercritical carbon dioxide

The Mannich-type reaction of imines with (1-methoxy-2-methylpropenyloxy)trimethylsilane and aza-Diels-Alder reaction of imines with Danishefsky's diene can be carried out in scCO₂ in the presence of lithium heptadecafluorooctanesulfonate which offer a way to synthesize β-amino carbonyl compounds and nitrogen-containing six-membered ring compounds under environmentally benign conditions.     

A novel and efficient approach to highly substituted indolizines via 5-endo-trig iodocyclization

A new approach to indolizines has been developed using a 5-endo-trig iodocyclization of allylic esters followed by isomerization and dehydroiodination facilitated by triethylamine at rt. This mild procedure enabled us to synthesize a number of highly substituted indolizines in good yields.     

Microwave-induced reactions: an alternative route for chemical synthesis

In an effort to study the scope of microwave radiation for organic bromination reactions, some reactions were studied using a domestic microwave oven. Results reveal that these radiation-induced reactions are unique in their high yields and that they require extremely short reaction times compared with conventional room-temperature reactions. In these reactions tetrabutyl ammonium tribromide was used as an alternative brominating reagent in order to avoid the chemical hazards associated with liquid bromine (Br₂). As all the reactions were successfully carried out in solid state under microwave conditions, the use of solvent was not required. All these aspects make the bromination protocol quite environment friendly.     

治疗良性前列腺增生药物的研究进展

良性前列腺增生是一种以前列腺增生并伴随下尿路症状为特点的常见疾病。目前治疗良性前列腺增生的药物有α-肾上腺素受体阻断剂、5α-还原酶抑制剂、植物花粉制剂以及民族医药等。现综述良性前列腺增生治疗药物的研究进展。     

One-pot tandem Barbier-Prins synthesis of tetrahydropyrans in aqueous media

Tetrahydropyran is an important structural core ofmany carbohydrates and their polymers. Its structure ispresent in numerous natural compounds such as poly-ether antibiotics, marine toxins and pheromones[1,2].Thus many reactions have been developed toward…