Stearyl coenzyme A desaturase(SCD), also known as delta-9 desaturase, catalyzes the rate-limiting step in the formation of monounsaturated fatty acids.In mammals, depletion or inhibition of SCD activity generally lead...Stearyl coenzyme A desaturase(SCD), also known as delta-9 desaturase, catalyzes the rate-limiting step in the formation of monounsaturated fatty acids.In mammals, depletion or inhibition of SCD activity generally leads to a decrease in triglycerides and cholesteryl esters. However, the endogenous role of scd in teleost fish remains unknown. Here, we generated a zebrafish scd mutant(scd-/-) to elucidate the role of scd in lipid metabolism and sexual development. Gas chromatography-mass spectrometry(GC-MS) showed that the scd-/- mutants had increased levels of saturated fatty acids C16:0 and C18:0, and decreased levels of monounsaturated fatty acids C16:1 and C18:1. The mutant fish displayed a short stature and an enlarged abdomen during development. Unlike Scd-/ -mammals, the scd-/- zebrafish showed significantly increased fat accumulation in the whole body,especially in the liver, leading to hepatic mitochondrial dysfunction and severe cell apoptosis.Mechanistically, srebf1, a gene encoding a transcriptional activator related to adipogenesis,acc1 and acaca, genes involved in fatty acid synthesis, and dgat2, a key gene involved in triglyceride synthesis, were significantly upregulated in mutant livers to activate fatty acid biosynthesis and adipogenesis. The scd-/- males exhibited defective natural mating behavior due to defective genital papillae but possessed functional mature sperm. All defects in the scd-/- mutants could be rescued by ubiquitous transgenic overexpression of scd. In conclusion, our study demonstrates that scd is indispensable for maintaining lipid homeostasis and development of secondary sexual characteristics in zebrafish.展开更多
The significant decrease of acid sites caused by alkali metal poisoning is the major factor in the deactivation of commercial V_(2)O_(5)-WO_(3)/TiO_(2)NH_(3)-SCR catalysts.In this work,the solid superacid SO_(4)^(2-)-...The significant decrease of acid sites caused by alkali metal poisoning is the major factor in the deactivation of commercial V_(2)O_(5)-WO_(3)/TiO_(2)NH_(3)-SCR catalysts.In this work,the solid superacid SO_(4)^(2-)-TiO_(2) modified by sulfate radicals,was selected as the catalyst support,which showed superior potassium resistance.The physicochemical properties and K-poisoning resistance of the V_(2)O_(5)-WO_(3)/SO_(4)^(2-)-TiO_(2)(VWSTi) catalyst were carried out by XRD,BET,H2-TPR,NH3-TPD,XPS,in situ DRIFTS and TG.The results pointed out that the introduction of SO_(4)^(2-)significantly increased the NH3-SCR catalytic activity at high temperatures,with an exceptionally high NO_(x) conversion over 90% between 275℃ and 500℃.When 0.5%(mass) K_(2)O was doped on the catalysts,the catalytic performance of the traditional V_(2)O_(5)-WO_(3)/TiO_(2)(VWTi) catalyst decreased significantly,while the VWSTi catalyst could still maintain a NOxconversion over 90%in the range of 300–500℃.The characterizations suggested that the support of SO_(4)^(2-)-TiO_(2) greatly increased the number of acidic sites,thereby enhancing the adsorption capacity of the reactant NH_(3).The results above demonstrated a potential approach to achieve superior potassium resistance for NH3-SCR catalysts using solid superacid.展开更多
Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaO...Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.展开更多
TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and th...TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.展开更多
CO_(2)capture with a low energy consumption is of important application significance for reducing CO_(2)emission.The phase-change absorbent developed in recent years shows its potential for low-energy CO_(2)capture.Th...CO_(2)capture with a low energy consumption is of important application significance for reducing CO_(2)emission.The phase-change absorbent developed in recent years shows its potential for low-energy CO_(2)capture.The unclear phase-splitting rule hinders the efficient development of CO_(2)phase-change absorbents.To predict phase-splitting behaviors of mono/poly-amine-organic solvent-water system with various concentrations,a quasi-activity coefficient was developed based on Debye&Mc Aulay equation and some Density function theory descriptors.Six models based on Debye&Mc Aulay equation were developed with different ion radius,descriptors or poly-amine-CO_(2)products.The phase-splitting boundary was drawn on the model with the best predictability.This quasi-activity coefficient would provide guidance for the phase-splitting systems development,especially for polyamines.展开更多
Pulsed chemical vapor deposition(P-CVD)is a promising technology for the surface modification of TiO_(2) particles.For the scale-up application of P-CVD,a custom-designed rotary reactor and corresponding coating proce...Pulsed chemical vapor deposition(P-CVD)is a promising technology for the surface modification of TiO_(2) particles.For the scale-up application of P-CVD,a custom-designed rotary reactor and corresponding coating process at room temperature was developed in the present work.The obtained SiO_(2)-coated TiO_(2) particles were characterized by various measures including high-resolution transmission electron microscope,Fourier transform infrared spectroscopy,X-ray diffraction,etc.The results illustrated that the SiO_(2) films with a thickness of(3.7±0.7)nm were successfully deposited onto the surface of TiO_(2) particles.According to the dye degradation tests and acid solubility measurement,the deposited film can effectively inhibit the photocatalytic activity and enhance the weatherability of the TiO_(2) particles.Zeta potential measurements showed that the SiO_(2)-coated TiO_(2) is possible to be stably dispersed in the pH range of 6.9–11.6.The coating process made the whiteness of TiO_(2) particles decreased slightly but still sufficient(97.3±0.1)for application.Furthermore,the properties of the TiO_(2) particles coated by PCVD were compared with the particles coated by traditional wet chemical deposition.It is shown that the P-CVD can produce thinner but denser films with better photoactivity suppression performance.The developed coating process within the rotary reactor was proved practically feasible and convenient for the scale-up production of SiO_(2)-coated TiO_(2) via P-CVD.展开更多
AIM: To investigate the microsatellite alterations in phenotypically normal esophageal squamous epithelium and metaplasia-dysplasia-adenocarcinoma sequence. METHODS: Forty-one specimens were obtained from esophageal c...AIM: To investigate the microsatellite alterations in phenotypically normal esophageal squamous epithelium and metaplasia-dysplasia-adenocarcinoma sequence. METHODS: Forty-one specimens were obtained from esophageal cancer (EC) patients. Histopathological assessment identified 23 squamous cell carcinomas (SCC) and 18 adenocarcinomas (ADC), including only 8 ADC with Barrett esophageal columnar epithelium (metaplasia) and dysplasia adjacent to ADC. Paraffin-embedded normal squamous epithelium, Barrett esophageal columnar epithelium (metaplasia), dysplasia and esophageal tumor tissues were dissected from the surrounding tissues under microscopic guidance. DNA was extracted using proteinase K digestion buffer, and DNA was diluted at 1:100, 1:1000, 1:5000, 1:10 000 and 1:50 000, respectively. Seven microsatellite markers (D2S123, D3S1616, D3S1300, D5S346, D17S787, D18S58 and BATRII loci) were used in this study. Un-dilution and dilution polymerase chainreactions (PCR) were performed, and microsatellite analysis was carried out. RESULTS: No statistically significant difference was found in microsatellite instability (MSI) and loss of heterozygosity (LOH) of un-diluted DNA between SCC and ADC. The levels of MSI and LOH were high in the metaplasia-dysplasia-adenocarcinoma sequence of diluted DNA. The more the diluted DNA was, the higher the rates of MSI and LOH were at the above 7 loci, especially at D3S1616, D5S346, D2S123, D3S1300 and D18S58 loci. CONCLUSION: The sequence of metaplasia-dysplasia-adenocarcinoma is associated with microsatellite alterations, including MSI and LOH. The MSI and LOH may be the early genetic events during esophageal carcinogenesis, and genetic alterations at the D3S1616, D5S346 and D3S123 loci may play a role in the progress of microsatellite alterations.展开更多
A low energy uneven cluster protocol design method is proposed. Aiming at the random choosing for cluster head of traditional Leach protocol, and the defect of the single hop from all the cluster heads to the sink nod...A low energy uneven cluster protocol design method is proposed. Aiming at the random choosing for cluster head of traditional Leach protocol, and the defect of the single hop from all the cluster heads to the sink node, an improved method for Leave protocol is advanced. Firstly, the election model of cluster head is improved, and the node residual energy is considered in the process of threshold and the cluster head election to improve the whole network life circle. In the multi-hop route, choosing the maximum energy and the nearest node as the next hop and a route transferring data among many clusters is formed. The experiment shows the method having great improvement compared with Leach protocol and prolonging the network life cycle.展开更多
The control method for SVG is researched in this paper. Based on the working mechanism of SVG, the logic switch function is introduced to establish the dynamic mathematic model. A differential geometry variable contro...The control method for SVG is researched in this paper. Based on the working mechanism of SVG, the logic switch function is introduced to establish the dynamic mathematic model. A differential geometry variable control method is provided and the differential geometry linear theory is used to convert the nonlinear system to a linear system. Then based on the former work the control of SVG is devised. Finally, the control of SVG is simulated and the result shows the differential geometry nonlinear control is robust and stable comparative to the traditional PID control method and it is an effective to control the SVG.展开更多
Ovarian Leydig cell tumor, a sub-type of ovarian steroid cell tumor, accounts for less than 0.1% of all ovarian tumors. It can affect women of any age group but is most common in postmenopausal women. We here report a...Ovarian Leydig cell tumor, a sub-type of ovarian steroid cell tumor, accounts for less than 0.1% of all ovarian tumors. It can affect women of any age group but is most common in postmenopausal women. We here report a case of virilizing ovarian Leydig cell tumor with multiple non-functional endocrine neoplasias (pituitary and adrenal adenomas) in a 48-year-old woman. She first presented with sub-abdominal pain and hirsutism since menopause three years ago. Subsequently, she had slight facial acne, voice deepening, breast atrophy, and a prominent Adam’s apple. Her hormone profile showed an elevated level of testosterone, high free androgen index, low levels of luteinizing hormone and follicle stimulating hormone, and normal levels of random cortisol, androstenedione, 17-hydroxyprogesterone and dehydroepiandrosterone sulfate. A pelvic enhanced magnetic resonance imaging (MRI) scan showed nodules in the right ovary, and a pituitary enhanced MRI revealed a microadenoma. An enhanced computerized tomography scan of the adrenal gland revealed left adrenal nodules, possibly adenomas. After a right cystectomy and right fallopian tube resection, her testosterone level declined to 0.38 nmol/L and the symptoms associated with hyperandrogenism improved. This is a rare case of virilizing ovarian Leydig cell tumor with multiple non-functional endocrine neoplasias. We believe our findings will be helpful in the clinical diagnosis and treatment of hyperandrogenism.展开更多
Aiming at the former formalized methods of robot planning should give the environment state, can not obtain the new knowledge of the environment. In order to improve the reason ability for obtaining new knowledge of t...Aiming at the former formalized methods of robot planning should give the environment state, can not obtain the new knowledge of the environment. In order to improve the reason ability for obtaining new knowledge of the environment state, the actions in the process of planning such as external action and sensing action are formalized. A formalized reasoning method—CPNI (Colored Petri Net for Planning in incomplete environment) based on two kinds of actions is proposed, and the reasoning rule as Fluent Calculus in incomplete environment is applied. Robot planning experiment is modeled and simulated by using the tool CPNTools and the result shows the state knowledge of the door and the action sequence to reach the goal can be generated automatically in the CPNI net system.展开更多
Aiming at the former formalized methods such as Strips, Situation Calculus and Fluent Calculus can not represent the action time and get the action sequence automatically, a novel method based on timed color Petri net...Aiming at the former formalized methods such as Strips, Situation Calculus and Fluent Calculus can not represent the action time and get the action sequence automatically, a novel method based on timed color Petri net—RPBTC was defined. The action time, the precondition and the post-condition of action are formalized in RPBTC based on the Fluent Calculus reasoning rules. An algorism for constructing the RPBTC net system based on bidirectional search strategy is proposed, and through executing the RPBTC net system, the action sequence for reaching the goal can be generated dynamically and the time for the robot reaching the goal also can be obtained. The experiment has proved the method RPBTC as a feasible method for robot planning.展开更多
A low energy consumption clustering algorism based on LEACH is researched. Firstly, A method for obtaining the number of clusters k is given, then using the K-Means algorism to divide all the sensor nodes in WSN to th...A low energy consumption clustering algorism based on LEACH is researched. Firstly, A method for obtaining the number of clusters k is given, then using the K-Means algorism to divide all the sensor nodes in WSN to the k clusters, in the whole network life cycle the cluster will not changed, and when the energy of cluster head is lower than some threshold, it will be changed. The data transmission between cluster heads to sink node use mixed model, namely, the cluster near the sink node using the single hop and the one far from it using the multiple hops. The experiment shows our method has the longer life cycle and more received information. It is an effective clustering protocol.展开更多
In order to solve the uneven node load in the tradition clustering routing protocols, a new clustering algorism based on SOM is proposed. Firstly, the network radio model and the energy consumption model are defined. ...In order to solve the uneven node load in the tradition clustering routing protocols, a new clustering algorism based on SOM is proposed. Firstly, the network radio model and the energy consumption model are defined. A new algorism using SOM to form the cluster and select the cluster head is defined. In the clustering node remain energy and the Euclidean distance from cluster head to the cluster member are considered. The experiment shows our method has the longer life cycle and less total energy consumption. It is an effective clustering protocol.展开更多
Aiming at region connection calculus (RCC) can only roughly represent spatial topological relations, and have difficulty in representing the distance, direction and so on. Therefore, based on RCC theory, Region Extens...Aiming at region connection calculus (RCC) can only roughly represent spatial topological relations, and have difficulty in representing the distance, direction and so on. Therefore, based on RCC theory, Region Extension and Shrinking Calculus are proposed, and then a formalized metrization method using region as a basic unit is introduced. Based on RESC theory, taking the advantage such as application simplicity and easy realization of gird area method. The experiment proves the spatial relations can be easily obtained by Grid-Region method, and it is an effective way to repre- sent spatial relations.展开更多
Microplastics(MPs)have become a significant concern for their potential toxicity.However,the correlation between the size of plastic particles and their toxicity remains inconclusive.Here,we investigate the toxic effe...Microplastics(MPs)have become a significant concern for their potential toxicity.However,the correlation between the size of plastic particles and their toxicity remains inconclusive.Here,we investigate the toxic effects of different sizes(80 nm,800 nm,8μm and 80μm)polystyrene MPs(PS-MPs)on the model organism Nile tilapia(Oreochromis niloticus).The results of bioluminescent imaging indicate that the 80 nm PS-MPs are more likely to invade the body.H&E staining shows severe damage on the intestinal villi and distinct hepatic steatosis in the 80 nm group.Ed U labeling shows that the proliferation activity of intestinal and liver cells reduces significantly in the 80 nm group.The gut microbiome analysis shows a severe imbalance of gut microbiota homeostasis in the 80 nm group.The analysis of liver transcriptomics and metabolomics shows that the liver lipid metabolism is disordered in the 80 nm group.In conclusion,this study confirms that the 80 nm PS-MPs are more likely to induce intestinal and liver toxicity.All the above lay the foundation for further study on the pathological damage of MPs to other organisms.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24010108)National Natural Science Foundation of China(31872554,32172952)Project from the State Key Laboratory of Freshwater Ecology and Biotechnology(2019FBZ05)。
文摘Stearyl coenzyme A desaturase(SCD), also known as delta-9 desaturase, catalyzes the rate-limiting step in the formation of monounsaturated fatty acids.In mammals, depletion or inhibition of SCD activity generally leads to a decrease in triglycerides and cholesteryl esters. However, the endogenous role of scd in teleost fish remains unknown. Here, we generated a zebrafish scd mutant(scd-/-) to elucidate the role of scd in lipid metabolism and sexual development. Gas chromatography-mass spectrometry(GC-MS) showed that the scd-/- mutants had increased levels of saturated fatty acids C16:0 and C18:0, and decreased levels of monounsaturated fatty acids C16:1 and C18:1. The mutant fish displayed a short stature and an enlarged abdomen during development. Unlike Scd-/ -mammals, the scd-/- zebrafish showed significantly increased fat accumulation in the whole body,especially in the liver, leading to hepatic mitochondrial dysfunction and severe cell apoptosis.Mechanistically, srebf1, a gene encoding a transcriptional activator related to adipogenesis,acc1 and acaca, genes involved in fatty acid synthesis, and dgat2, a key gene involved in triglyceride synthesis, were significantly upregulated in mutant livers to activate fatty acid biosynthesis and adipogenesis. The scd-/- males exhibited defective natural mating behavior due to defective genital papillae but possessed functional mature sperm. All defects in the scd-/- mutants could be rescued by ubiquitous transgenic overexpression of scd. In conclusion, our study demonstrates that scd is indispensable for maintaining lipid homeostasis and development of secondary sexual characteristics in zebrafish.
基金supported by the National Natural Science Foundation of China (22108184)China Postdoctoral Science Foundation (2021TQ0221)+1 种基金the Sichuan Science and Technology Program (2021JDRC0117)Chengdu Science and Technology Program (2021-YF05-00378-SN)。
文摘The significant decrease of acid sites caused by alkali metal poisoning is the major factor in the deactivation of commercial V_(2)O_(5)-WO_(3)/TiO_(2)NH_(3)-SCR catalysts.In this work,the solid superacid SO_(4)^(2-)-TiO_(2) modified by sulfate radicals,was selected as the catalyst support,which showed superior potassium resistance.The physicochemical properties and K-poisoning resistance of the V_(2)O_(5)-WO_(3)/SO_(4)^(2-)-TiO_(2)(VWSTi) catalyst were carried out by XRD,BET,H2-TPR,NH3-TPD,XPS,in situ DRIFTS and TG.The results pointed out that the introduction of SO_(4)^(2-)significantly increased the NH3-SCR catalytic activity at high temperatures,with an exceptionally high NO_(x) conversion over 90% between 275℃ and 500℃.When 0.5%(mass) K_(2)O was doped on the catalysts,the catalytic performance of the traditional V_(2)O_(5)-WO_(3)/TiO_(2)(VWTi) catalyst decreased significantly,while the VWSTi catalyst could still maintain a NOxconversion over 90%in the range of 300–500℃.The characterizations suggested that the support of SO_(4)^(2-)-TiO_(2) greatly increased the number of acidic sites,thereby enhancing the adsorption capacity of the reactant NH_(3).The results above demonstrated a potential approach to achieve superior potassium resistance for NH3-SCR catalysts using solid superacid.
基金the support from the National Natural Science Foundation of China (22008157,21978178)。
文摘Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.
基金Supported by the National Key R&D Program of China(2018YFB0605700).
文摘TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.
基金financial support from National Natural Science Foundation of China(21878190)China Petrochemical Corporation(419033-1)the Engineering Experimental Teaching Center,School of Chemical Engineering,Sichuan University for the Nuclear Magnetic Resonance(NMR,JNM-ECZ400S/L1,JEOL Ltd.)support and the compute server support。
文摘CO_(2)capture with a low energy consumption is of important application significance for reducing CO_(2)emission.The phase-change absorbent developed in recent years shows its potential for low-energy CO_(2)capture.The unclear phase-splitting rule hinders the efficient development of CO_(2)phase-change absorbents.To predict phase-splitting behaviors of mono/poly-amine-organic solvent-water system with various concentrations,a quasi-activity coefficient was developed based on Debye&Mc Aulay equation and some Density function theory descriptors.Six models based on Debye&Mc Aulay equation were developed with different ion radius,descriptors or poly-amine-CO_(2)products.The phase-splitting boundary was drawn on the model with the best predictability.This quasi-activity coefficient would provide guidance for the phase-splitting systems development,especially for polyamines.
基金supported by the National Key Research and Development Program of China(2018YFB0605700)National Natural Science Foundation of China(21908150)China Postdoctoral Science Foundation(2019M653404)。
文摘Pulsed chemical vapor deposition(P-CVD)is a promising technology for the surface modification of TiO_(2) particles.For the scale-up application of P-CVD,a custom-designed rotary reactor and corresponding coating process at room temperature was developed in the present work.The obtained SiO_(2)-coated TiO_(2) particles were characterized by various measures including high-resolution transmission electron microscope,Fourier transform infrared spectroscopy,X-ray diffraction,etc.The results illustrated that the SiO_(2) films with a thickness of(3.7±0.7)nm were successfully deposited onto the surface of TiO_(2) particles.According to the dye degradation tests and acid solubility measurement,the deposited film can effectively inhibit the photocatalytic activity and enhance the weatherability of the TiO_(2) particles.Zeta potential measurements showed that the SiO_(2)-coated TiO_(2) is possible to be stably dispersed in the pH range of 6.9–11.6.The coating process made the whiteness of TiO_(2) particles decreased slightly but still sufficient(97.3±0.1)for application.Furthermore,the properties of the TiO_(2) particles coated by PCVD were compared with the particles coated by traditional wet chemical deposition.It is shown that the P-CVD can produce thinner but denser films with better photoactivity suppression performance.The developed coating process within the rotary reactor was proved practically feasible and convenient for the scale-up production of SiO_(2)-coated TiO_(2) via P-CVD.
基金The Xiamen Science and Technology Founda-tion (No. 3502Z20052018)Xiamen Healthy Bureau Research Foundation (No. WSK0301)
文摘AIM: To investigate the microsatellite alterations in phenotypically normal esophageal squamous epithelium and metaplasia-dysplasia-adenocarcinoma sequence. METHODS: Forty-one specimens were obtained from esophageal cancer (EC) patients. Histopathological assessment identified 23 squamous cell carcinomas (SCC) and 18 adenocarcinomas (ADC), including only 8 ADC with Barrett esophageal columnar epithelium (metaplasia) and dysplasia adjacent to ADC. Paraffin-embedded normal squamous epithelium, Barrett esophageal columnar epithelium (metaplasia), dysplasia and esophageal tumor tissues were dissected from the surrounding tissues under microscopic guidance. DNA was extracted using proteinase K digestion buffer, and DNA was diluted at 1:100, 1:1000, 1:5000, 1:10 000 and 1:50 000, respectively. Seven microsatellite markers (D2S123, D3S1616, D3S1300, D5S346, D17S787, D18S58 and BATRII loci) were used in this study. Un-dilution and dilution polymerase chainreactions (PCR) were performed, and microsatellite analysis was carried out. RESULTS: No statistically significant difference was found in microsatellite instability (MSI) and loss of heterozygosity (LOH) of un-diluted DNA between SCC and ADC. The levels of MSI and LOH were high in the metaplasia-dysplasia-adenocarcinoma sequence of diluted DNA. The more the diluted DNA was, the higher the rates of MSI and LOH were at the above 7 loci, especially at D3S1616, D5S346, D2S123, D3S1300 and D18S58 loci. CONCLUSION: The sequence of metaplasia-dysplasia-adenocarcinoma is associated with microsatellite alterations, including MSI and LOH. The MSI and LOH may be the early genetic events during esophageal carcinogenesis, and genetic alterations at the D3S1616, D5S346 and D3S123 loci may play a role in the progress of microsatellite alterations.
文摘A low energy uneven cluster protocol design method is proposed. Aiming at the random choosing for cluster head of traditional Leach protocol, and the defect of the single hop from all the cluster heads to the sink node, an improved method for Leave protocol is advanced. Firstly, the election model of cluster head is improved, and the node residual energy is considered in the process of threshold and the cluster head election to improve the whole network life circle. In the multi-hop route, choosing the maximum energy and the nearest node as the next hop and a route transferring data among many clusters is formed. The experiment shows the method having great improvement compared with Leach protocol and prolonging the network life cycle.
文摘The control method for SVG is researched in this paper. Based on the working mechanism of SVG, the logic switch function is introduced to establish the dynamic mathematic model. A differential geometry variable control method is provided and the differential geometry linear theory is used to convert the nonlinear system to a linear system. Then based on the former work the control of SVG is devised. Finally, the control of SVG is simulated and the result shows the differential geometry nonlinear control is robust and stable comparative to the traditional PID control method and it is an effective to control the SVG.
文摘Ovarian Leydig cell tumor, a sub-type of ovarian steroid cell tumor, accounts for less than 0.1% of all ovarian tumors. It can affect women of any age group but is most common in postmenopausal women. We here report a case of virilizing ovarian Leydig cell tumor with multiple non-functional endocrine neoplasias (pituitary and adrenal adenomas) in a 48-year-old woman. She first presented with sub-abdominal pain and hirsutism since menopause three years ago. Subsequently, she had slight facial acne, voice deepening, breast atrophy, and a prominent Adam’s apple. Her hormone profile showed an elevated level of testosterone, high free androgen index, low levels of luteinizing hormone and follicle stimulating hormone, and normal levels of random cortisol, androstenedione, 17-hydroxyprogesterone and dehydroepiandrosterone sulfate. A pelvic enhanced magnetic resonance imaging (MRI) scan showed nodules in the right ovary, and a pituitary enhanced MRI revealed a microadenoma. An enhanced computerized tomography scan of the adrenal gland revealed left adrenal nodules, possibly adenomas. After a right cystectomy and right fallopian tube resection, her testosterone level declined to 0.38 nmol/L and the symptoms associated with hyperandrogenism improved. This is a rare case of virilizing ovarian Leydig cell tumor with multiple non-functional endocrine neoplasias. We believe our findings will be helpful in the clinical diagnosis and treatment of hyperandrogenism.
文摘Aiming at the former formalized methods of robot planning should give the environment state, can not obtain the new knowledge of the environment. In order to improve the reason ability for obtaining new knowledge of the environment state, the actions in the process of planning such as external action and sensing action are formalized. A formalized reasoning method—CPNI (Colored Petri Net for Planning in incomplete environment) based on two kinds of actions is proposed, and the reasoning rule as Fluent Calculus in incomplete environment is applied. Robot planning experiment is modeled and simulated by using the tool CPNTools and the result shows the state knowledge of the door and the action sequence to reach the goal can be generated automatically in the CPNI net system.
文摘Aiming at the former formalized methods such as Strips, Situation Calculus and Fluent Calculus can not represent the action time and get the action sequence automatically, a novel method based on timed color Petri net—RPBTC was defined. The action time, the precondition and the post-condition of action are formalized in RPBTC based on the Fluent Calculus reasoning rules. An algorism for constructing the RPBTC net system based on bidirectional search strategy is proposed, and through executing the RPBTC net system, the action sequence for reaching the goal can be generated dynamically and the time for the robot reaching the goal also can be obtained. The experiment has proved the method RPBTC as a feasible method for robot planning.
文摘A low energy consumption clustering algorism based on LEACH is researched. Firstly, A method for obtaining the number of clusters k is given, then using the K-Means algorism to divide all the sensor nodes in WSN to the k clusters, in the whole network life cycle the cluster will not changed, and when the energy of cluster head is lower than some threshold, it will be changed. The data transmission between cluster heads to sink node use mixed model, namely, the cluster near the sink node using the single hop and the one far from it using the multiple hops. The experiment shows our method has the longer life cycle and more received information. It is an effective clustering protocol.
文摘In order to solve the uneven node load in the tradition clustering routing protocols, a new clustering algorism based on SOM is proposed. Firstly, the network radio model and the energy consumption model are defined. A new algorism using SOM to form the cluster and select the cluster head is defined. In the clustering node remain energy and the Euclidean distance from cluster head to the cluster member are considered. The experiment shows our method has the longer life cycle and less total energy consumption. It is an effective clustering protocol.
文摘Aiming at region connection calculus (RCC) can only roughly represent spatial topological relations, and have difficulty in representing the distance, direction and so on. Therefore, based on RCC theory, Region Extension and Shrinking Calculus are proposed, and then a formalized metrization method using region as a basic unit is introduced. Based on RESC theory, taking the advantage such as application simplicity and easy realization of gird area method. The experiment proves the spatial relations can be easily obtained by Grid-Region method, and it is an effective way to repre- sent spatial relations.
基金supported by China Agriculture Research System (No.CARS-46)the Central Public-interest Scienti?c Institution Basal Research Fund,CAFS (No.YFI202208)the National Natural Science Foundation of China (Nos.31872554and 32172952)
文摘Microplastics(MPs)have become a significant concern for their potential toxicity.However,the correlation between the size of plastic particles and their toxicity remains inconclusive.Here,we investigate the toxic effects of different sizes(80 nm,800 nm,8μm and 80μm)polystyrene MPs(PS-MPs)on the model organism Nile tilapia(Oreochromis niloticus).The results of bioluminescent imaging indicate that the 80 nm PS-MPs are more likely to invade the body.H&E staining shows severe damage on the intestinal villi and distinct hepatic steatosis in the 80 nm group.Ed U labeling shows that the proliferation activity of intestinal and liver cells reduces significantly in the 80 nm group.The gut microbiome analysis shows a severe imbalance of gut microbiota homeostasis in the 80 nm group.The analysis of liver transcriptomics and metabolomics shows that the liver lipid metabolism is disordered in the 80 nm group.In conclusion,this study confirms that the 80 nm PS-MPs are more likely to induce intestinal and liver toxicity.All the above lay the foundation for further study on the pathological damage of MPs to other organisms.
