Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, s...Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian展开更多
Three novel bicyclic taxane diterpenoids with the rare 6/12-membered rings wereisolated from the need ies of Taxus chinensis var. mairei. The structures were established with the help of 1D and 2D NMR spectral analysis.
We propose a new experimentally verified ghost imaging(GI) mechanism,derivative GI.Our innovation is that we use the derivatives of the intensities of the test light and the reference light for imaging.Experimental re...We propose a new experimentally verified ghost imaging(GI) mechanism,derivative GI.Our innovation is that we use the derivatives of the intensities of the test light and the reference light for imaging.Experimental results show that by combining derivative GI with the standard GI algorithm,multiple independent signals can be obtained in one measurement.This combination greatly reduces the number of measurements and the time required for data acquisition and imaging.Derivative GI intrinsically does not produce the storage-consuming background term of GI,so it is suitable for on-chip implementation and makes practical application of GI easier.展开更多
PURPOSE: This study was designed to investigate whether characteristics, prognostic risk factors, and survival of colorectal cancer of Japanese-Americans in Hawaii are different from those of native Japanese in Japan....PURPOSE: This study was designed to investigate whether characteristics, prognostic risk factors, and survival of colorectal cancer of Japanese-Americans in Hawaii are different from those of native Japanese in Japan. METHODS: A retrospective review of patients with colorectal cancer surgically resected in single institutions in Hawaii and Japan from 1996 to 2002. RESULTS: A total of 410 Japanese-American patients (218 males; median age, 73 years) and 621 native Japanese patients (382 males; median age, 65 years) were included. There were significant differences in age (P < 0.001), age distribution (P < 0.001), gender (P= 0.008), preoperative carcinoembryonic antigen (P < 0.001), and anatomic site distribution (P < 0.001). The tumor characteristics of Japanese- American patients were close to the general American population compared with the Surveillance, Epidemiology, and End Results data. There were no differences in tumor size, histologic grade, each of T, N, M status and TNM stage between the two groups. The overall five-year survival rates (Japanese-Americans, 75.5 percent; native Japanese, 76.2 percent; P = 0.55) and survival rates in each of four stratified stages were similar. Risk factors associated with survival were not different, except for carcinoembryonic antigen (P = 0.036). CONCLUSIONS: In patients with colorectal cancer in Japanese-Americans in Hawaii, some of tumor characteristics have changed from those of native Japanese in Japan. However, there are no remarkable differences in prognostic factors and survival between the two groups. The present study suggests that certain changes of colorectal cancer characteristics that were seen in Japanese-American may occur in native Japanese in Japan in the near future, although the survival-outcome of colorectal cancer may remain the same.展开更多
In the southern part of China, due to the rich rainfalls and favourably topographical landscape, there is abundant hydraulic energy resources contained in the countless small streams and rivers in the mountainous and ...In the southern part of China, due to the rich rainfalls and favourably topographical landscape, there is abundant hydraulic energy resources contained in the countless small streams and rivers in the mountainous and semi-mountainous areas. Besides the small hydro power generation which transfers the potential energy to the electrical power, there is other technology available to utilise the potential energy directly for the water lifting in the irrigation and decentralised do-mestic water supply in the village level. This paper introduces the basic principle of the hydraulic ram op-eration and describes the applicable opportunities for the hydraulic ram.展开更多
Background During the COVID-19 pandemic,decreased volumes of stroke admissions and mechanical thrombectomy were reported.The study’s objective was to examine whether subarachnoid haemorrhage(SAH)hospitalisations and ...Background During the COVID-19 pandemic,decreased volumes of stroke admissions and mechanical thrombectomy were reported.The study’s objective was to examine whether subarachnoid haemorrhage(SAH)hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.Methods We conducted a cross-sectional,retrospective,observational study across 6 continents,37 countries and 140 comprehensive stroke centres.Patients with the diagnosis of SAH,aneurysmal SAH,ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases,10th Revision,codes.The 3-month cumulative volume,monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before(1 year and immediately before)and during the pandemic,defined as 1 March-31 May 2020.The prior 1-year control period(1 March-31 May 2019)was obtained to account for seasonal variation.Findings There was a significant decline in SAH hospitalisations,with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic,representing a relative decline of 22.5%(95%CI−24.3%to−20.7%,p<0.0001).Embolisation of ruptured aneurysms declined with 1170-1035 procedures,respectively,representing an 11.5%(95%CI−13.5%to−9.8%,p=0.002)relative drop.Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations,a 24.9%relative decline(95%CI−28.0%to−22.1%,p<0.0001).A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1%(95%CI 32.3%to 50.6%,p=0.008)despite a decrease in SAH admissions in this tertile.Interpretation There was a relative decrease in the volume of SAH hospitalisations,aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic.These findings in SAH are consistent with a decrease in other emergencies,such as stroke and myocardial infarction.展开更多
Seven types of microcystins,isolated from Microcystis waterbloom in Lake Dalai, were characterized.The major toxins:MCYST-LR,MCYST-RR,[D-Asp^3]MCYST-LR and [Dha^7]MCYST-LR were identified by high performance liquid ch...Seven types of microcystins,isolated from Microcystis waterbloom in Lake Dalai, were characterized.The major toxins:MCYST-LR,MCYST-RR,[D-Asp^3]MCYST-LR and [Dha^7]MCYST-LR were identified by high performance liquid chromatography(HPLC),as com- pared with the authentic microcystins.The minor toxins:MCYST FR,[L-Mser^7]MCYST-LR and an unknown MCYST which was most likely to be MCYST-(H_4)YR were identified with frit- fast atom bombardment liquid chromatography/mass spectrometry(Frit-FAB LC/MS)and amino acid analysis.The toxigenic diversity in blue-green algae(cyanobacteria)was discussed.展开更多
文摘Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian
文摘Three novel bicyclic taxane diterpenoids with the rare 6/12-membered rings wereisolated from the need ies of Taxus chinensis var. mairei. The structures were established with the help of 1D and 2D NMR spectral analysis.
基金supported by the National Natural Science Foundation of China (No. 51727805)the support from the National Natural Science Foundation of China (No. 12104251)
文摘We propose a new experimentally verified ghost imaging(GI) mechanism,derivative GI.Our innovation is that we use the derivatives of the intensities of the test light and the reference light for imaging.Experimental results show that by combining derivative GI with the standard GI algorithm,multiple independent signals can be obtained in one measurement.This combination greatly reduces the number of measurements and the time required for data acquisition and imaging.Derivative GI intrinsically does not produce the storage-consuming background term of GI,so it is suitable for on-chip implementation and makes practical application of GI easier.
文摘PURPOSE: This study was designed to investigate whether characteristics, prognostic risk factors, and survival of colorectal cancer of Japanese-Americans in Hawaii are different from those of native Japanese in Japan. METHODS: A retrospective review of patients with colorectal cancer surgically resected in single institutions in Hawaii and Japan from 1996 to 2002. RESULTS: A total of 410 Japanese-American patients (218 males; median age, 73 years) and 621 native Japanese patients (382 males; median age, 65 years) were included. There were significant differences in age (P < 0.001), age distribution (P < 0.001), gender (P= 0.008), preoperative carcinoembryonic antigen (P < 0.001), and anatomic site distribution (P < 0.001). The tumor characteristics of Japanese- American patients were close to the general American population compared with the Surveillance, Epidemiology, and End Results data. There were no differences in tumor size, histologic grade, each of T, N, M status and TNM stage between the two groups. The overall five-year survival rates (Japanese-Americans, 75.5 percent; native Japanese, 76.2 percent; P = 0.55) and survival rates in each of four stratified stages were similar. Risk factors associated with survival were not different, except for carcinoembryonic antigen (P = 0.036). CONCLUSIONS: In patients with colorectal cancer in Japanese-Americans in Hawaii, some of tumor characteristics have changed from those of native Japanese in Japan. However, there are no remarkable differences in prognostic factors and survival between the two groups. The present study suggests that certain changes of colorectal cancer characteristics that were seen in Japanese-American may occur in native Japanese in Japan in the near future, although the survival-outcome of colorectal cancer may remain the same.
文摘In the southern part of China, due to the rich rainfalls and favourably topographical landscape, there is abundant hydraulic energy resources contained in the countless small streams and rivers in the mountainous and semi-mountainous areas. Besides the small hydro power generation which transfers the potential energy to the electrical power, there is other technology available to utilise the potential energy directly for the water lifting in the irrigation and decentralised do-mestic water supply in the village level. This paper introduces the basic principle of the hydraulic ram op-eration and describes the applicable opportunities for the hydraulic ram.
文摘Background During the COVID-19 pandemic,decreased volumes of stroke admissions and mechanical thrombectomy were reported.The study’s objective was to examine whether subarachnoid haemorrhage(SAH)hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.Methods We conducted a cross-sectional,retrospective,observational study across 6 continents,37 countries and 140 comprehensive stroke centres.Patients with the diagnosis of SAH,aneurysmal SAH,ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases,10th Revision,codes.The 3-month cumulative volume,monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before(1 year and immediately before)and during the pandemic,defined as 1 March-31 May 2020.The prior 1-year control period(1 March-31 May 2019)was obtained to account for seasonal variation.Findings There was a significant decline in SAH hospitalisations,with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic,representing a relative decline of 22.5%(95%CI−24.3%to−20.7%,p<0.0001).Embolisation of ruptured aneurysms declined with 1170-1035 procedures,respectively,representing an 11.5%(95%CI−13.5%to−9.8%,p=0.002)relative drop.Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations,a 24.9%relative decline(95%CI−28.0%to−22.1%,p<0.0001).A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1%(95%CI 32.3%to 50.6%,p=0.008)despite a decrease in SAH admissions in this tertile.Interpretation There was a relative decrease in the volume of SAH hospitalisations,aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic.These findings in SAH are consistent with a decrease in other emergencies,such as stroke and myocardial infarction.
文摘Seven types of microcystins,isolated from Microcystis waterbloom in Lake Dalai, were characterized.The major toxins:MCYST-LR,MCYST-RR,[D-Asp^3]MCYST-LR and [Dha^7]MCYST-LR were identified by high performance liquid chromatography(HPLC),as com- pared with the authentic microcystins.The minor toxins:MCYST FR,[L-Mser^7]MCYST-LR and an unknown MCYST which was most likely to be MCYST-(H_4)YR were identified with frit- fast atom bombardment liquid chromatography/mass spectrometry(Frit-FAB LC/MS)and amino acid analysis.The toxigenic diversity in blue-green algae(cyanobacteria)was discussed.
