A practical 2.45-GHz microwave-driven Cs-free H^- source was improved based on the experimental H^- source at Peking University（PKU）. Several structural improvements were implemented to meet the practical requiremen...A practical 2.45-GHz microwave-driven Cs-free H^- source was improved based on the experimental H^- source at Peking University（PKU）. Several structural improvements were implemented to meet the practical requirements of Xi＇an Proton Application Facility（XiPaf）. Firstly, the plasma chamber size was optimized to enhance the plasma intensity and stability. Secondly, the filter magnetic field and electron deflecting magnetic field were enhanced to reduce co-extracted electrons. Thirdly, a new two-electrode extraction system with farther electrode gap and enhanced water cooling ability to diminish spark and sputter during beam extraction was applied. At last, the direct H^- current measuring method was adopted by the arrangement of a new pair of bending magnets before Faraday cup（FC） to remove residual electrons. With these improvements, electron cyclotron resonance（ECR） magnetic field optimization experiments and operation parameter variation experiments were carried out on the H^- ion source and a maximum 8.5-mA pure H^- beam was extracted at 50 kV with the time structure of 100 Hz/0.3 ms. The root-mean-square（RMS） emittance of the beam is 0.25 Π·mm·mrad. This improved H^- source and extraction system were maintenance-free for more than 200 hours in operation.展开更多
AIM: To investigate the expression of TWIK-related arachidonic acid-stimulated K+ channel(TRAAK) in retinal degeneration mice(rd1) and further evaluate how TRAAK affect photoreceptor cell apoptosis.METHODS: The rd1 mi...AIM: To investigate the expression of TWIK-related arachidonic acid-stimulated K+ channel(TRAAK) in retinal degeneration mice(rd1) and further evaluate how TRAAK affect photoreceptor cell apoptosis.METHODS: The rd1 mice were distributed into blank(no treatment), control(1.4% DMSO, intraperitoneal injection) and riluzole groups(4 mg/kg·d, intraperitoneal injection) from postnatal 7 d to 10, 14 and 18 d;C57 group(no treatment), as age-matched wild-type control. The thickness of the outer nuclear layer(ONL) of retina was detected by paraffin section hematoxylin and eosin staining. The expression of TRAAK and the apoptosis of the ONL cells were detected by immunostaining, Western blotting, and real-time polymerase chain reaction. RESULTS: The channel agonist riluzole activated TRAAK and delayed the apoptosis of photoreceptor cells in ONL layer of rd1 mice. Both at mRNA and protein levels, after riluzole treatment, TRAAK expression was significantly upregulated, when compared with the control and blank group. Then we detected a series of apoptosis related mRNA and protein. The anti-apoptotic factor Bcl-2 downregulated and the pro-apoptotic factors Bax and cleaved-caspase-3 upregulated significantly. CONCLUSION: Riluzole elevates the expression of TRAAK and inhibits the development of apoptosis. Activation of TRAAK may have some potential effects to put off photoreceptor apoptosis.展开更多
A miniaturized 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion source, which has the ability of producing a tens-m A H＋beam, has been built and tested at Peking University（PKU）. Its plasma chamb...A miniaturized 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion source, which has the ability of producing a tens-m A H＋beam, has been built and tested at Peking University（PKU）. Its plasma chamber dimension is Φ30 mm×40 mm and the whole size of the ion source is Φ180 mm×130 mm. This source has a unique structure with the whole source body embedded into the extraction system. It can be operated in both continuous wave（CW） mode and pulse mode. In the CW mode, more than 20 m A hydrogen ion beam at 40 k V can be obtained with the microwave power of 180 W and about 1 m A hydrogen ion beam is produced with a microwave power of 10 W. In the pulse mode, more than50 m A hydrogen ion beam with a duty factor of 10% can be extracted when the peak microwave power is 1800 W.展开更多
Two new apotirucallane triterpenoids,namely chisiamols G(1)and H(2),featuring a 21,23-lactone,together with five known triterpenoids,were isolated from the twigs of Chisocheton paniculatus.The structures of the new co...Two new apotirucallane triterpenoids,namely chisiamols G(1)and H(2),featuring a 21,23-lactone,together with five known triterpenoids,were isolated from the twigs of Chisocheton paniculatus.The structures of the new compounds were elucidated on the basis of spectroscopic and chemical methods.展开更多
1.Objective The Bainaimiao Arc Belt(BAB),one of the most important units of the southeastern Central Asian Orogenic Belt(CAOB),locates along the northern margin of the North China Craton(NCC).There is a lack of unders...1.Objective The Bainaimiao Arc Belt(BAB),one of the most important units of the southeastern Central Asian Orogenic Belt(CAOB),locates along the northern margin of the North China Craton(NCC).There is a lack of understanding on the existence,scale,and affinity of the crystalline basement of the BAB.Based on the recent geochronologic studies.展开更多
Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene ...Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775007 and 11575013)
文摘A practical 2.45-GHz microwave-driven Cs-free H^- source was improved based on the experimental H^- source at Peking University（PKU）. Several structural improvements were implemented to meet the practical requirements of Xi＇an Proton Application Facility（XiPaf）. Firstly, the plasma chamber size was optimized to enhance the plasma intensity and stability. Secondly, the filter magnetic field and electron deflecting magnetic field were enhanced to reduce co-extracted electrons. Thirdly, a new two-electrode extraction system with farther electrode gap and enhanced water cooling ability to diminish spark and sputter during beam extraction was applied. At last, the direct H^- current measuring method was adopted by the arrangement of a new pair of bending magnets before Faraday cup（FC） to remove residual electrons. With these improvements, electron cyclotron resonance（ECR） magnetic field optimization experiments and operation parameter variation experiments were carried out on the H^- ion source and a maximum 8.5-mA pure H^- beam was extracted at 50 kV with the time structure of 100 Hz/0.3 ms. The root-mean-square（RMS） emittance of the beam is 0.25 Π·mm·mrad. This improved H^- source and extraction system were maintenance-free for more than 200 hours in operation.
基金Supported by National Natural Science Foundation of China (No.81271012)
文摘AIM: To investigate the expression of TWIK-related arachidonic acid-stimulated K+ channel(TRAAK) in retinal degeneration mice(rd1) and further evaluate how TRAAK affect photoreceptor cell apoptosis.METHODS: The rd1 mice were distributed into blank(no treatment), control(1.4% DMSO, intraperitoneal injection) and riluzole groups(4 mg/kg·d, intraperitoneal injection) from postnatal 7 d to 10, 14 and 18 d;C57 group(no treatment), as age-matched wild-type control. The thickness of the outer nuclear layer(ONL) of retina was detected by paraffin section hematoxylin and eosin staining. The expression of TRAAK and the apoptosis of the ONL cells were detected by immunostaining, Western blotting, and real-time polymerase chain reaction. RESULTS: The channel agonist riluzole activated TRAAK and delayed the apoptosis of photoreceptor cells in ONL layer of rd1 mice. Both at mRNA and protein levels, after riluzole treatment, TRAAK expression was significantly upregulated, when compared with the control and blank group. Then we detected a series of apoptosis related mRNA and protein. The anti-apoptotic factor Bcl-2 downregulated and the pro-apoptotic factors Bax and cleaved-caspase-3 upregulated significantly. CONCLUSION: Riluzole elevates the expression of TRAAK and inhibits the development of apoptosis. Activation of TRAAK may have some potential effects to put off photoreceptor apoptosis.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB845502)the National Natural Science Foundation of China(Grant No.11575013)
文摘A miniaturized 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion source, which has the ability of producing a tens-m A H＋beam, has been built and tested at Peking University（PKU）. Its plasma chamber dimension is Φ30 mm×40 mm and the whole size of the ion source is Φ180 mm×130 mm. This source has a unique structure with the whole source body embedded into the extraction system. It can be operated in both continuous wave（CW） mode and pulse mode. In the CW mode, more than 20 m A hydrogen ion beam at 40 k V can be obtained with the microwave power of 180 W and about 1 m A hydrogen ion beam is produced with a microwave power of 10 W. In the pulse mode, more than50 m A hydrogen ion beam with a duty factor of 10% can be extracted when the peak microwave power is 1800 W.
基金Financial support of the National Natural Science Foundation(Grant No.21072203)National Science and Technology Major Project“Key New Drug Creation and Manufacturing Program”(No.2011ZX09307-002-03)of China is gratefully acknowledged.
文摘Two new apotirucallane triterpenoids,namely chisiamols G(1)and H(2),featuring a 21,23-lactone,together with five known triterpenoids,were isolated from the twigs of Chisocheton paniculatus.The structures of the new compounds were elucidated on the basis of spectroscopic and chemical methods.
基金Supported by the projects of China Geological Survey(DD20230004,DD20190039-06,DD20190360-2,DD20190360,DD20221632-01)the National Natural Science Foundation of China(42002227).
文摘1.Objective The Bainaimiao Arc Belt(BAB),one of the most important units of the southeastern Central Asian Orogenic Belt(CAOB),locates along the northern margin of the North China Craton(NCC).There is a lack of understanding on the existence,scale,and affinity of the crystalline basement of the BAB.Based on the recent geochronologic studies.
基金the National Natural Science Foundation of China(31671088 and 31730041)the Natural Science Foundation of Shaanxi Province,China(2017ZDJC-01)。
文摘Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.
