As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a ca...As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.展开更多
In recent decades, biotechnology produced a growth of knowledge on the causes and mechanisms of metabolic diseases that have formed the basis for their study, diagnosis and treatment. Unfortunately, it is well known t...In recent decades, biotechnology produced a growth of knowledge on the causes and mechanisms of metabolic diseases that have formed the basis for their study, diagnosis and treatment. Unfortunately, it is well known that the clinical features of metabolic diseases can manifest themselves with very different characteristics and escape early detection. Also, it is well known that the prognosis of many metabolic diseases is excellent if diagnosed and treated early. In this editorial we briefly summarized two groups of inherited metabolic diseases, the defects of cholesterol biosynthesis and those of bile acids. Both groups show variable clinical manifestations but some clinical signs and symptoms are common in both the defects of cholesterol and bile acids. The differential diagnosis can be made analyzing sterol profiles in blood and/or bile acids in blood and urine by chromatographic techniques(GC-MS and LC-MS/MS). Several defects of both biosynthetic pathways are treatable so early diagnosis is crucial. Unfortunately their diagnosis is made too late, due either to the clinical heterogeneity of the syndromes(severe, mild and very mild) that to the scarcity of scientific dissemination of these rare diseases. Therefore, the delay in diagnosis leads the patient to the medical observation when the disease has produced irreversible damages to the body. Here, we highlighted simple clinical and laboratory descriptions that can potentially make you to suspect a defect in cholesterol biosynthesis and/or bile acids, as well, we suggest appropriate request of the laboratory tests that along with common clinical features can help to diagnose these defects.展开更多
Due to the harmful effect of free radical on physiological and pathological state of our body on one hand, and the increase of the fungal infection on the other hand, drug that can reduce free radical and inhibit fung...Due to the harmful effect of free radical on physiological and pathological state of our body on one hand, and the increase of the fungal infection on the other hand, drug that can reduce free radical and inhibit fungal growth is needed. This work aims to evaluate the antioxidant and antifungal activities of the Ocimum gratissimum L. essential oils from center and west region of Cameroon. Essential oil was analyzed by GC （gas chromatography） and GC coupled with MS （mass spectrometry）. The antioxidant activities of essential oils were studied by the Diphenylpicrylhydrazyl method and the β-carotene bleaching test. The antifungal activities were assessed using micro-dilution technique for yeasts and agar dilution method for Aspergillus. Thymol and γ-terpinene, eugenol and thymol were the major compounds for Yaounde and Dschang, respectively. The scavenging capacity of sample from Dschang was higher than that of Yaounde. Also, the β-carotene bleaching tests of the sample from Dschang were better than that from Yaounde. The antifungal activity of the sample from Yaounde was higher than that from Dschang on yeasts and Aspergillus isolates, respectively. This work presents and compares the chemical composition, antioxidant and antifungal activity of Ocimum gratissimum essential oil from center and west region of Cameroon.展开更多
In this study, seven alkaloids were detected in Wu-tou decoction using ultra performance liquid chromatography coupled with tandem mass spectrometry （UPLC-MSn）. The aim of this study was to investigate the effect of...In this study, seven alkaloids were detected in Wu-tou decoction using ultra performance liquid chromatography coupled with tandem mass spectrometry （UPLC-MSn）. The aim of this study was to investigate the effect of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, Pinelliae Rhizoma in different ratios with Wu-tou decoction （2：1, 1：1, 1：2） by measuring the therapeutic effects in Wu-tou decoction of main seven alkaloids including benzoylaconitine （BA）, benzoylmesaconitine （BM）, benzoylhypaconitine （BH）, hypaconitine （HA）, fuziline （FU）, niaolin （NE） and deoxyaconitine （DA）. The permeability of aconitum alkaloids extract through a Caco-2 cell monolayer was analyzed in the absence and presence of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, and Pinelliae Rhizoma, respectively. The results showed that Pinelliae Rhizoma could reduce the absorption of the alkaloids and increase the excretion of the alkaloids, which would attenuate the therapeutic effects of Wu-tou decoction. Therefore, Pinelliae Rhizoma is an incompatible herb of Wu-tou decoction because of the inhibition of the absorption of alkaloids in the intestine. And that Fritillariae Cirrhosae Bulbus and Fritillariae rhunbergii Bulbus showed the effects to improve the permeability of the alkaloids in Wu-tou decoction. These effects of these two herbs were similar, but the former was stronger than the latter, which most likely is due to the fact that the compositions of these two traditional Chinese medicines are similar. The in vitro data suggests that the compounds such as fritillary presented in alkaloids in the formula maybe improve the therapeutic function caused by the increased bioavailability of alkaloids in intestine.展开更多
Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle s...Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation.In total,110 rats were sacrificed and stored at a constant temperature(25℃).Rat skeletal muscle samples were collected at 0-10‑day postmortem,and then the VOCs were determined using a method of headspace solid‑phase microextraction coupled with gas chromatography‑mass spectrometry.The correlations between the VOCs(species and quantities)and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25℃were established for different PMIs.To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation,ten additional rats with known PMIs were studied.We identified 15 kinds of VOCs and the number of VOC species increased with the PMI.The total peak areas of the VOCs increased significantly with the postmortem day(adjusted R^(2)=0.96-0.97).The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%.We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice.Although the preliminary results are encouraging,further studies in human cadavers under real case conditions are needed.展开更多
基金funded by the Major State Basic Research Development Program of China(973 project,Grant No.2012CB214803)National Science and Technology Major Project of China(Grant No. 2016ZX05003-005)National Natural Science Foundation of China(Grant Nos.41322017 and 41472100)
文摘As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.
文摘In recent decades, biotechnology produced a growth of knowledge on the causes and mechanisms of metabolic diseases that have formed the basis for their study, diagnosis and treatment. Unfortunately, it is well known that the clinical features of metabolic diseases can manifest themselves with very different characteristics and escape early detection. Also, it is well known that the prognosis of many metabolic diseases is excellent if diagnosed and treated early. In this editorial we briefly summarized two groups of inherited metabolic diseases, the defects of cholesterol biosynthesis and those of bile acids. Both groups show variable clinical manifestations but some clinical signs and symptoms are common in both the defects of cholesterol and bile acids. The differential diagnosis can be made analyzing sterol profiles in blood and/or bile acids in blood and urine by chromatographic techniques(GC-MS and LC-MS/MS). Several defects of both biosynthetic pathways are treatable so early diagnosis is crucial. Unfortunately their diagnosis is made too late, due either to the clinical heterogeneity of the syndromes(severe, mild and very mild) that to the scarcity of scientific dissemination of these rare diseases. Therefore, the delay in diagnosis leads the patient to the medical observation when the disease has produced irreversible damages to the body. Here, we highlighted simple clinical and laboratory descriptions that can potentially make you to suspect a defect in cholesterol biosynthesis and/or bile acids, as well, we suggest appropriate request of the laboratory tests that along with common clinical features can help to diagnose these defects.
文摘Due to the harmful effect of free radical on physiological and pathological state of our body on one hand, and the increase of the fungal infection on the other hand, drug that can reduce free radical and inhibit fungal growth is needed. This work aims to evaluate the antioxidant and antifungal activities of the Ocimum gratissimum L. essential oils from center and west region of Cameroon. Essential oil was analyzed by GC （gas chromatography） and GC coupled with MS （mass spectrometry）. The antioxidant activities of essential oils were studied by the Diphenylpicrylhydrazyl method and the β-carotene bleaching test. The antifungal activities were assessed using micro-dilution technique for yeasts and agar dilution method for Aspergillus. Thymol and γ-terpinene, eugenol and thymol were the major compounds for Yaounde and Dschang, respectively. The scavenging capacity of sample from Dschang was higher than that of Yaounde. Also, the β-carotene bleaching tests of the sample from Dschang were better than that from Yaounde. The antifungal activity of the sample from Yaounde was higher than that from Dschang on yeasts and Aspergillus isolates, respectively. This work presents and compares the chemical composition, antioxidant and antifungal activity of Ocimum gratissimum essential oil from center and west region of Cameroon.
基金supported by the National Natural Sciences Foundation of China(No.81274046)National Basic Research Program of China("973 Program")(Nos.2011CB505300, 2011CB505305)
文摘In this study, seven alkaloids were detected in Wu-tou decoction using ultra performance liquid chromatography coupled with tandem mass spectrometry （UPLC-MSn）. The aim of this study was to investigate the effect of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, Pinelliae Rhizoma in different ratios with Wu-tou decoction （2：1, 1：1, 1：2） by measuring the therapeutic effects in Wu-tou decoction of main seven alkaloids including benzoylaconitine （BA）, benzoylmesaconitine （BM）, benzoylhypaconitine （BH）, hypaconitine （HA）, fuziline （FU）, niaolin （NE） and deoxyaconitine （DA）. The permeability of aconitum alkaloids extract through a Caco-2 cell monolayer was analyzed in the absence and presence of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, and Pinelliae Rhizoma, respectively. The results showed that Pinelliae Rhizoma could reduce the absorption of the alkaloids and increase the excretion of the alkaloids, which would attenuate the therapeutic effects of Wu-tou decoction. Therefore, Pinelliae Rhizoma is an incompatible herb of Wu-tou decoction because of the inhibition of the absorption of alkaloids in the intestine. And that Fritillariae Cirrhosae Bulbus and Fritillariae rhunbergii Bulbus showed the effects to improve the permeability of the alkaloids in Wu-tou decoction. These effects of these two herbs were similar, but the former was stronger than the latter, which most likely is due to the fact that the compositions of these two traditional Chinese medicines are similar. The in vitro data suggests that the compounds such as fritillary presented in alkaloids in the formula maybe improve the therapeutic function caused by the increased bioavailability of alkaloids in intestine.
基金This research was partially supported by China Scholarship Council(CSC 201707070113).
文摘Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation.In total,110 rats were sacrificed and stored at a constant temperature(25℃).Rat skeletal muscle samples were collected at 0-10‑day postmortem,and then the VOCs were determined using a method of headspace solid‑phase microextraction coupled with gas chromatography‑mass spectrometry.The correlations between the VOCs(species and quantities)and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25℃were established for different PMIs.To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation,ten additional rats with known PMIs were studied.We identified 15 kinds of VOCs and the number of VOC species increased with the PMI.The total peak areas of the VOCs increased significantly with the postmortem day(adjusted R^(2)=0.96-0.97).The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%.We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice.Although the preliminary results are encouraging,further studies in human cadavers under real case conditions are needed.
