7 results on '"SUN Chen-chen"'
Search Results
2. Pore structure of nano-porous thermal insulating materials and thermal transport via gas phase in their pores
- Author
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YANG Hai-long, HU Zi-jun, SUN Chen-cheng, HU Sheng-bo, and YANG Jing-xing
- Subjects
nano-porous thermal insulating materials ,gas-contributed thermal conductivity ,gaseous thermal conductivity ,pore structure ,equivalent pore diameter ,Mining engineering. Metallurgy ,TN1-997 ,Environmental engineering ,TA170-171 - Abstract
The thermal insulation properties of nano-porous thermal insulating materials largely depend on thermal transport via gas phase within their pores, and this process relies on their pore structures. Therefore, investigating pore structures and thermal transport via gas phase is important to understand the heat transfer mechanism. Current research mainly focuses on the theoretical calculation and analysis from the perspective of heat transfer, and special and systematic studies based on actual materials have not been reported yet. In addition, accurate analysis of pore structures using usual techniques is difficult due to the complex pore network and the poor mechanical properties of their solid skeleton. In this study, nano-porous thermal insulating materials with different pore structures were synthesized via a sol-gel process followed by supercritical drying. The materials were then characterized by thermal conductivity tester, nitrogen adsorption-desorption, and helium pycnometer. The pore structures of the resulting materials were obtained, and the relationship between pore structures and thermal transport via gas phase was studied. Results show that the bimodal distribution of pores in the resulting materials, corresponding to gas-contributed thermal conductivity. All pores within the resulting materials can be equivalent to pores with a single diameter when the equivalent size of large pores is 10 times less than that of small pores. Similar to the pure gaseous thermal conductivity, the intrinsic gas-contributed thermal conductivity including gas-solid coupling effects rises with increasing pore diameter of the materials. The ratio of intrinsic gas-contributed thermal conductivity to pure gaseous thermal conductivity is 2.0, 1.5, and 2.0-1.5 for pores smaller than 200 nm, larger than 500 nm, and with size between 200 and 500 nm, respectively. When the equivalent size of large pores is 10 times less than that of small pores or when the equivalent size of large pores is 100-1000 times that of small pores and the contribution of large pores to the total porosity is less than 10%, the gas-contributed thermal conductivity reduction of the resulting material with decreasing gas pressure can be divided into three stages (steep decreasing stage, slow decreasing stage, and hardly changing stage) according to decreasing rate. When the equivalent size of large pores is 3000 times larger than that of small pores, the gas-contributed thermal conductivity reduction of the resulting material with decreasing gas pressure can be divided into four stages (steep decreasing stage, slow decreasing stage, steep decreasing stage, and hardly changing stage) even if the contribution of large pores to the total porosity is very low (less than 10%).
- Published
- 2019
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3. [Experience of Integrative Palliative Care at Peking Union Medical College Hospital].
- Author
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Geng RX, Zheng Y, Sun CC, Zeng X, Fang HY, Zhan WQ, Yu YF, Yang Q, Dai XY, and Ning XH
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, China, Palliative Care methods
- Abstract
Objective To summarize the experience of integrative palliative care at Peking Union Medical College Hospital and provide a reference for promoting the integrative palliative care model. Methods Twenty cases receiving integrative palliative care at Peking Union Medical College Hospital were collected.The clinical characteristics,reasons for initiating integrative palliative care,the process of integrative palliative care,and feedback from these cases were summarized. Results Insomnia (11 cases,55%) and pain (9 cases,45%) were the most common symptoms requiring control in the 20 cases.The integrative palliative care team assisted in medical decision-making for 17 cases (85%),prepared end-of-life for 9 cases (45%),assisted in the transfer for 3 cases (15%),and provided comfort care for all the 20 cases (100%). Conclusions The integrative palliative care model can help alleviate suffering in end-of-life patients and provide support to patients' families and the original medical teams.This model is worth further promotion within class A tertiary hospitals.
- Published
- 2024
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4. [Effect of Dendrobium officinale superfine powder on stomach Yin deficiency model mice induced by "spicy overeating"].
- Author
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Chen QQ, Su J, DU YZ, Sun CC, Chen SH, and Lyu GY
- Subjects
- Animals, Hyperphagia, Male, Mice, Mice, Inbred ICR, Powders, Stomach, Dendrobium, Yin Deficiency
- Abstract
Dendrobium officinale is a traditional Chinese medicine for nourishing Yin and benefiting stomach. Its superfine powder has many advantages, such as good dissolution, high utilization rate, strong integrity and easy to use. However, the researches on effect of D. officinale superfine powder on stomach Yin deficiency model are still not sufficient. In this experiment, we explored the effect of D. officinale superfine powder in mice model with stomach Yin deficiency caused by "spicy overeating", and provided certain reference value for its application in gastrointestinal diseases. Male ICR mice were randomly divided into normal group, model group, Yiweitang group, omeprazole group, and D. officinale superfine powder high, medium and low dose groups. The mixture of wine and pepper liquid was given by gavage administration for 30 d, and the corresponding drug was given for 60 d while the model was conti-nued. The body weight, food intake, water intake, fecal moisture content and particle number, foot temperature of mice were measured. The levels of serum gastrin(Gas), motilin(MTL) and somatostatin(SS) were measured by ELISA. Gastric histomorpho-logy was observed by HE staining. The expression levels of nuclear factor kappa B(NF-κB) and cyclooxygenase-2(COX-2) were determined by immunohistochemistry. The expression levels of B-cell lymphoma-2(Bcl-2) and Bcl-2 associated X protein(Bax) in gastric tissues were detected by Western blot. The results showed that D. officinale superfine powder could increase the food intake, water intake, fecal moisture content and particle number, reduce the foot temperature, improve the pathological changes of gastric mucosa, reduce the expression of NF-κB, COX-2 protein in gastric tissues, and increase the ratio of Bax/Bcl-2. D. officinale superfine powder can "nourish Yin and benefit the stomach", improve the syndrome of stomach Yin deficiency, such as "hunger but not want to eat, dry mouth but not want to drink, hand and feet hot, constipation", and reduce the damage of gastric mucosa. The mechanism may be related to regulating the secretion of gastrointestinal hormones, inhibiting the inflammation of gastric tissues and promoting the apoptosis of abnormal cells in gastric tissues.
- Published
- 2021
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5. [Effect of Dendrobium officinale on Yin deficiency constipation induced by warm-drying medicine in mice].
- Author
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Sun CC, Su J, Yan MQ, Chen QQ, Chen SH, and Lyu GY
- Subjects
- Animals, Colon, Constipation drug therapy, Female, Male, Mice, Mice, Inbred ICR, Dendrobium, Yin Deficiency drug therapy, Yin Deficiency genetics
- Abstract
Dendrobium officinale is a sacred product for nourishing Yin and has a clear "thick gastrointestinal" effect. Modern pharmacological studies had found that it could improve gastrointestinal function. This study observed the improvement effect of D. officinale on constipation model mice with Yin deficiency caused by warm-drying medicine. It provided experimental basis for the treatment of Yin deficiency constipation. The male and female ICR mice were randomly divided into normal group, model group, D. officinale high, medium and low dose groups(0.6, 0.4, 0.2 g·kg~(-1)), and phenolphthalein tablets group. The model mice of Yin deficiency constipation were established by gavage with warm-drying medicine. The overall state and body temperature of the mice were observed and recorded. The number of feces, feces weight, fecal moisture content and intestinal propulsion were measured. The morphological damage of colon tissue was observed by hematoxylin-eosin(HE) staining. The expression of inducible nitric oxide synthase(iNOS) in the colon was detected by Western blot and immunohistochemical method. The expression of iNOS mRNA in the colon was detected by Real-time fluorescence quantitative PCR, and the serum cyclic guanosine phosphate(cGMP) level was detected the enzyme-linked immunosorbent assay(ELISA). The results showed that D. candidum could reduce the body temperature of mice with Yin deficiency constipation, increase the number of feces, wet feces, dry feces and intestinal propulsion ability, reduce the expression of iNOS protein and mRNA in the colon, and reduce the content of cGMP in the serum. It showed that D. candidum could improve the symptoms of Yin deficiency constipation mice caused by warm-drying medicine, and the mechanism may be related to reducing the expression of iNOS in the colon and increasing intestinal motility.
- Published
- 2021
- Full Text
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6. [Effect of Wubi Shanyao Pills on sexual dysfunction in rats with adenine-induced kidney-Yang deficiency].
- Author
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Fang P, Su J, Chen W, Zhu JM, Yu JJ, Yan MQ, Sun CC, Huang QD, Liu T, Chen SH, and Lyu GY
- Subjects
- Animals, Follicle Stimulating Hormone, Gonadotropin-Releasing Hormone, Luteinizing Hormone, Male, Rats, Rats, Sprague-Dawley, Testis, Testosterone, Adenine, Yang Deficiency
- Abstract
The aim of this paper was to study the effect of Wubi Shanyao Pills on sexual dysfunction in rats with kidney-Yang deficiency and to investigate its possible mechanism. Adenine(100 mg·kg~(-1)) was administered to male SD rats for 8 weeks to establish kidney-Yang deficiency model, and at the same time, Wubi Shanyao Pills(2, 1, 0.5 g·kg~(-1)) were administered to rats for 8 weeks. The syndrome manifestation of kidney-Yang deficiency was observed in rats and the scores of symptoms were evaluated. Sexual behavior indexes(incubation period and times of capture, straddle and ejaculation) were measured by mating experiment. The levels of serum testosterone(T), estradiol(E_2), follicle stimulating hormone(FSH), luteinizing hormone(LH), and gonadotropin releasing hormone(GnRH) were measured by radioimmunoassay. The wet weights of testis and seminal vesicle were measured. The content of fructose in seminal plasma was detected by UV spectrophotometry. The pathological changes of testis and epididymis were observed by HE staining. The expression levels of transforming growth factor(TGF-β1) and cytochrome P450 aromatase(CYP19) in testis were detected by immunohistochemistry and Western blot. The results showed that Wubi Shanyao Pills could significantly reduce the score of kidney-Yang deficiency syndrome, improve the symptoms of kidney-Yang deficiency syndrome, shorten capture, straddle and ejaculation latency, increase capture and straddle times, increase serum T, LH, FSH, E_2 and GnRH levels, increase the wet weight of testis and seminal vesicle and fructose content in seminal plasma, improve the pathological structure of testis and epididymis, and inhibit the expression of TGF-β1 and increase CYP19 in testis of the model rats. Therefore, Wubi Shanyao Pills can significantly improve sexual dysfunction in rats with kidney-Yang deficiency, and its mechanism may be related to regulating the low function of hypothalamus pituitary gonad(HPG) axis and improving the disorder of sex hormone secretion. In addition, it may be also related to inhibiting the expression of testicular TGF-β1, increasing the expression of CYP19 protein, and then regulating the amount of T converted to E_2.
- Published
- 2020
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7. [Response and adaptation of photosynthesis of cucumber seedlings to high temperature stress].
- Author
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Sun SN, Wang Q, Sun CC, Liu FJ, Bi HG, and Ai XZ
- Subjects
- Light, Plant Leaves, Seedlings, Temperature, Cucumis sativus, Photosynthesis
- Abstract
Cucumber seedlings (Cucumis sativus Jinyou 35) were used to study the effects of high temperature (HT: 42 ℃/32 ℃) and sub-high temperature (SHT: 35 ℃/25 ℃) on its photosynthesis and growth. The results showed that the growth of cucumber seedlings was dramatically inhibited by the high and sub-high temperature stresses. The photosynthetic rate (P
n ) was gradually reduced, while intercellular CO2 concentration (Ci ) was increased as heat stress lasted. Under heat stress, stomatal conductance (gs ), transpiration rate (Tr ), photorespiration rate (Pr ) and dark respiration rate (Dr ) showed a trend from rise to decline in cucumber seedlings, which implied that heat-induced decline of photosynthesis was mainly due to non-stomatal limitation. Maximal photochemical efficiency of PS2 in darkness (Fv /Fm ), actual photochemical efficiency (χPS 2 ), photochemical quenching (qP ) and electron transport rate (ETR) were severely hampered, while initial fluorescence (Fo ) and non-chemical quenching (NPQ) were increased as a result of high and sub-high temperature stresses. Under extended high temperature stress, the activities of RuBP carboxylase (RuBPCase) and Rubisco activase (RCA) as well as the mRNA abundance of Rubisco and RCA were in the trend of decrease, while they were reduced 3 days following the sub-high temperature treatment. The activities and mRNA expressions of sedoheptulose-1,7-bisphosphatase (SBPase) and fructose 1,6-bisphosphate aldolase (FBA) increased initially, but decreased afterwards under heat stress. Taken together, our data suggested that short-term sub-high temperature did not cause photoinhibition under optimal light conditions, however, high temperature led to severe damage to PS2 reaction center in cucumber seedlings. The photosynthetic enzymes were induced by high temperature stress and the induction was affected by temperature and stress duration.- Published
- 2017
- Full Text
- View/download PDF
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