The spatial and temporal changes in aeolian transport over a dune are fundamental factors that control the morphology of the dune. In the present study, we obtained direct field observations of aeolian transport over ...The spatial and temporal changes in aeolian transport over a dune are fundamental factors that control the morphology of the dune. In the present study, we obtained direct field observations of aeolian transport over a developing transverse dune at the Shapotou Aeolian Experiment Site in the southeastern part of China's Tengger Desert. The transport rate versus wind speed relationship relationships over flat surfaces and over dunes that are s complicated over a developing dune compared with the n equilibrium with the wind. We obtained trend lines for transport rate over the transverse dune versus distance. The transport rate generally increased from the toe to the crest above the stoss slope, but the difference in transport rate between the crest and the toe was smaller than those that have been proposed for taller dunes. The crest/toe ratio for transport rates therefore seems to depend greatly on dune height. Flux density profiles for different points above the dune at different wind speeds were well described by the exponential decay law, as has been proposed for saltation flux density profiles. Coefficients in the flux density profile function can be defined in terms of the transport rate and wind speed. However, the dependence of relative decay rate with height and average saltation height on wind speed was weaker than that observed in a wind tunnel and above a fiat surface. The preliminary results obtained in this study require more evidence from field observations to fully describe aeolian transport above developing dunes.展开更多
BACKGROUND Accumulating clinical evidence has shown that diabetes mellitus(DM)is a serious risk factor for cardiovascular disorders and an important factor for adverse cardiovascular events.AIM To explore the value of...BACKGROUND Accumulating clinical evidence has shown that diabetes mellitus(DM)is a serious risk factor for cardiovascular disorders and an important factor for adverse cardiovascular events.AIM To explore the value of the combined determination of the neutrophil-lymphocyte ratio(NLR)and red blood cell distribution width(RDW)in the early diagnosis and prognosis evaluation of DM complicated with heart failure(HF).METHODS We retrospectively analyzed clinical data on 65 patients with type 2 DM(T2DM)complicated with HF(research group,Res)and 60 concurrent patients with uncomplicated T2DM(control group,Con)diagnosed at Zhejiang Provincial People’s Hospital between January 2019 and December 2021.The NLR and RDW values were determined and comparatively analyzed,and their levels in T2DM+HF patients with different cardiac function grades were recorded.The receiver operating characteristic(ROC)curves were plotted to determine the NLR and RDW values(alone and in combination)for the early diagnosis of HF.The correlation between NLR and RDW with the presence or absence of cardiac events was also investigated.RESULTS Higher NLR and RDW levels were identified in the Res vs the Con groups(P<0.05).The NLR and RDW increased gradually and synchronously with the deterioration of cardiac function in the Res group,with marked differences in their levels among patients with grade II,III,and IV HF(P<0.05).ROC curve analysis revealed that NLR combined with RDW detection had an area under the curve of 0.915,a sensitivity of 76.9%,and a specificity of 100%for the early diagnosis of HF.Furthermore,HF patients with cardiac events showed higher NLR and RDW values compared with HF patients without cardiac events.CONCLUSION NLR and RDW were useful laboratory indicators for the early diagnosis of DM complicated with HF,and their joint detection was beneficial for improving diagnostic efficiency.Additionally,NLR and RDW values were directly proportional to patient outcomes.展开更多
Systemic lupus erythematosus (SLE) is a typical autoimmune disease involving multiple systems and organs. Ample evidence suggests that autoreactive T cells play a pivotal role in the development of this autoimmune d...Systemic lupus erythematosus (SLE) is a typical autoimmune disease involving multiple systems and organs. Ample evidence suggests that autoreactive T cells play a pivotal role in the development of this autoimmune disorder. This study was undertaken to investigate the mechanisms of interaction between antigen presenting cells (APCs) and an autoreactive T cell (ATLI) clone obtained from lupus-prone BXSB mice. ATLI cells, either before or after 7-ray irradiation, were able to activate naive B cells, as determined by B cell proliferation assays. Macrophages from BXSB mice were able to stimulate the proliferation of resting ATL 1 cells at a responder/stimulator (R/S) ratio of 1/2.5. Dendritic cells (DCs) were much more powerful stimulators for ATLI cells on a per cell basis. The T cell stimulating ability ofmacrophages and B cells, but not DCs, was sensitive to T-ray irradiation. Monoclonal antibodies against mouse MHC-Ⅱ and CD4 were able to block DC-mediated stimulation of ATL 1 proliferation, indicating cognate recognition between ATL 1 and APCs. Our data suggest that positive feedback loops involving macrophages, B cells and autoreactive T cells may play a pivotal role in keeping the momentum of autoimmune responses leading to autoimmune diseases.展开更多
With the introduction of software defined hardware by DARPA Electronics Resurgence Initiative,software definition will be the basic attribute of information system.Benefiting from boundary certainty and algorithm aggr...With the introduction of software defined hardware by DARPA Electronics Resurgence Initiative,software definition will be the basic attribute of information system.Benefiting from boundary certainty and algorithm aggregation of domain applications,domain-oriented computing architecture has become the technical direction that considers the high flexibility and efficiency of information system.Aiming at the characteristics of data-intensive computing in different scenarios such as Internet of Things(IoT),big data,artificial intelligence(AI),this paper presents a domain-oriented software defined computing architecture,discusses the hierarchical interconnection structure,hybrid granularity computing element and its computational kernel extraction method,finally proves the flexibility and high efficiency of this architecture by experimental comparison.展开更多
Cementing carbonate reservoirs is generally a difficult task.The so-called thixotropic cement slurry has gained considerable attention in this regard as it can help tofix some notable problems.More precisely,it can ea...Cementing carbonate reservoirs is generally a difficult task.The so-called thixotropic cement slurry has gained considerable attention in this regard as it can help tofix some notable problems.More precisely,it can easilyfill the leakage layer;moreover,its gelling strength can grow rapidly when pumping stops,thereby increasing the resistance to gas channeling,effectively preventing this undesired phenomenon in many cases.High-temperature thixotropic cement slurry systems,however,are still in an early stage of development and additional research is needed to make them a viable option.In the present study,using a self-developed composite high-temperature thixotropic additive as a basis,it is shown that the compressive strength can be adjusted by tuning the proportion of silica sand,the high-temperature retarder,fluid loss additive and dispersant(compatible with the thixotropic additive).According to the tests,the developed high-temperature thixotropic cement slurry system has a 14 d compressive strength of 29.73 MPa at 150°C,and a thickening time of 330 min when the dosage of retarder is 2%.At the same time,the rheological property,water loss,permeability,water separation rate,and settlement stability of the cement slurry system meet the requirements of cementing construction.展开更多
We consider harmonic moments of branching processes in general random environments. For a sequence of square integrable random variables, we give some conditions such that there is a positive constant c that every var...We consider harmonic moments of branching processes in general random environments. For a sequence of square integrable random variables, we give some conditions such that there is a positive constant c that every variable in this sequence belong to Ac or A1c uniformly.展开更多
This study was undertaken to investigate whether levels of anti-Saccharomyces cerevisiae mannan antibodies (ASCMA) in human sera, a marker for several autoimmune diseases, correlate with rheumatoid arthritis (RA)....This study was undertaken to investigate whether levels of anti-Saccharomyces cerevisiae mannan antibodies (ASCMA) in human sera, a marker for several autoimmune diseases, correlate with rheumatoid arthritis (RA). ASCMA-IgA, -IgG and -IgM levels were measured with enzyme linked immunosorbent assays (ELISA) in patients with RA (n = 30) and 152 healthy adult controls. ASCMA-IgA prevalence was significantly higher in RA patients (40%) than in healthy subjects (5.3%). A strong correlation between levels of ASCMA-IgA and CRP (r = 0.695; p 〈 0.01) and ESR (r = 0.708; p 〈 0.01) in RA patients was observed. No significant differences in ASCMA-IgG or IgM levels were noted between RA patients and healthy control subjects in the present study. This result differs from previous reports. It remains to be evaluated whether elevated ASCMA-levels are common to all rheumatic disorders.展开更多
Leukocyte differentiation antigens (LDAs) play important roles in the immune system, by serving as surface markers and participating in multiple biological activities, such as recognizing pathogens, mediating membra...Leukocyte differentiation antigens (LDAs) play important roles in the immune system, by serving as surface markers and participating in multiple biological activities, such as recognizing pathogens, mediating membrane signals, interacting with other cells or systems, and regulating cell differentiation and activation. Data mining is a powerful tool used to identify novel LDAs from whole genome. LRRC25 (leucine rich repeat-containing 25) was predicted to have a role in the function of myeloid cells by a large-scale "omics" data analysis. Further experimental validation showed that LRRC25 is highly expressed in primary myeloid cells, such as granulocytes and monocytes, and lowly/intermediately expressed in B cells, but not in T cells and almost all NK cells. It was down-regulated in multiple acute myeloid leukemia (AML) cell lines and bone marrow cells of AML patients and up-regulated after all-trans retinoic acid (ATRA)-mediated granulocytic differentiation in AML cell lines and acute promyelocytic leukemia (APL; AML-M3, FAB classification) cells. Localization analysis showed that LRRC25 is a type I transmembrane molecule. Although ectopic LRRC25 did not promote spontaneous differentiation of NB4 cells, knockdown of LRRC25 by siRNA or shRNA and knockout of LRRC25 by the CRISPR-Cas9 system attenuated ATRA-induced termi- nal granulocytic differentiation, and restoration of LRRC25 in knockout cells could rescue ATRA-induced granulocytic differentiation. Therefore, LRRC25, a potential leukocyte differentiation antigen, is a key regulator of ATRA-induced granulocytic differentiation.展开更多
Constitutionally adaptive chemistry of selenium-containing crown ethers(CEs) offers a new platform for controlling/switching the hydration of bolaamphiphile skeletons in water in an effective and simple manner by the ...Constitutionally adaptive chemistry of selenium-containing crown ethers(CEs) offers a new platform for controlling/switching the hydration of bolaamphiphile skeletons in water in an effective and simple manner by the virtue of covalent bonding. The adaptive behaviour of the macrocyclic bolaamphiphiles(transformations between C7SeBola and C7SeOBola) in response to redox environment was found to be a decisive factor.展开更多
Inbred strains of mice and rats are widely used in preclinical investigations evaluating the effectiveness of glycan-based biomecines,however,the glycan specificity repertoires of serum Abs in rodents have not been fu...Inbred strains of mice and rats are widely used in preclinical investigations evaluating the effectiveness of glycan-based biomecines,however,the glycan specificity repertoires of serum Abs in rodents have not been fully characterized.In the present study,serum antibodies in naïve mice and rats of different inbred strains were analyzed for specificity against 4 representative carbohydrate structures including PGA(1,4-linkeda-D-galactopyranosyluronic acids),b-glucan,mannan anda-glucan(dextran).Mannan was not recognized by serum Abs from any of the mouse and rat strains.Serum IgM in naïve F344,BN and Lewis rats recognized PGA andb-glucan and,less strongly,dextran.High titer circulating IgM against PGA were found in mice of BALB/c,C57BL/6,C3H/NeH and BXSB strains.C3H/NeH was the only strain which also produced low titer IgM against β-glucan and dextran.Age-related production of high titer IgM,IgA and IgG Abs against β-glucan was observed in BXSB mice.Intraperitoneal immunization of BALB/c and C57BL/6 mice with β-glucan elicited strong IgM responses,while immunization with PGA also led to an increase of anti-PGA IgM Ab titers.These results provide useful information on the characteristics of glycan-specific natural antibody repertoires in rodents.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
A novel diselenide-containing crown ether(BC7Se_(2))was fabricated,which can polymerize to form cyclic oligomers through intermolecular dynamic covalent reaction by irradiation of visible light.The size and distributi...A novel diselenide-containing crown ether(BC7Se_(2))was fabricated,which can polymerize to form cyclic oligomers through intermolecular dynamic covalent reaction by irradiation of visible light.The size and distribution of oligomers are related to the monomer concentration.The decomposition reaction of oligomers is controlled by topology and solvents.Furthermore,potassium cation can inhibit the polymerization of BC7Se_(2)and accelerate the decomposition of oligomers.展开更多
基金funding from the National Natural Science Foundation of China (41130533, 41171010)
文摘The spatial and temporal changes in aeolian transport over a dune are fundamental factors that control the morphology of the dune. In the present study, we obtained direct field observations of aeolian transport over a developing transverse dune at the Shapotou Aeolian Experiment Site in the southeastern part of China's Tengger Desert. The transport rate versus wind speed relationship relationships over flat surfaces and over dunes that are s complicated over a developing dune compared with the n equilibrium with the wind. We obtained trend lines for transport rate over the transverse dune versus distance. The transport rate generally increased from the toe to the crest above the stoss slope, but the difference in transport rate between the crest and the toe was smaller than those that have been proposed for taller dunes. The crest/toe ratio for transport rates therefore seems to depend greatly on dune height. Flux density profiles for different points above the dune at different wind speeds were well described by the exponential decay law, as has been proposed for saltation flux density profiles. Coefficients in the flux density profile function can be defined in terms of the transport rate and wind speed. However, the dependence of relative decay rate with height and average saltation height on wind speed was weaker than that observed in a wind tunnel and above a fiat surface. The preliminary results obtained in this study require more evidence from field observations to fully describe aeolian transport above developing dunes.
基金Supported by Zhejiang Province Traditional Chinese Medicine Science and 158 Technology Project,No.2023ZL008.
文摘BACKGROUND Accumulating clinical evidence has shown that diabetes mellitus(DM)is a serious risk factor for cardiovascular disorders and an important factor for adverse cardiovascular events.AIM To explore the value of the combined determination of the neutrophil-lymphocyte ratio(NLR)and red blood cell distribution width(RDW)in the early diagnosis and prognosis evaluation of DM complicated with heart failure(HF).METHODS We retrospectively analyzed clinical data on 65 patients with type 2 DM(T2DM)complicated with HF(research group,Res)and 60 concurrent patients with uncomplicated T2DM(control group,Con)diagnosed at Zhejiang Provincial People’s Hospital between January 2019 and December 2021.The NLR and RDW values were determined and comparatively analyzed,and their levels in T2DM+HF patients with different cardiac function grades were recorded.The receiver operating characteristic(ROC)curves were plotted to determine the NLR and RDW values(alone and in combination)for the early diagnosis of HF.The correlation between NLR and RDW with the presence or absence of cardiac events was also investigated.RESULTS Higher NLR and RDW levels were identified in the Res vs the Con groups(P<0.05).The NLR and RDW increased gradually and synchronously with the deterioration of cardiac function in the Res group,with marked differences in their levels among patients with grade II,III,and IV HF(P<0.05).ROC curve analysis revealed that NLR combined with RDW detection had an area under the curve of 0.915,a sensitivity of 76.9%,and a specificity of 100%for the early diagnosis of HF.Furthermore,HF patients with cardiac events showed higher NLR and RDW values compared with HF patients without cardiac events.CONCLUSION NLR and RDW were useful laboratory indicators for the early diagnosis of DM complicated with HF,and their joint detection was beneficial for improving diagnostic efficiency.Additionally,NLR and RDW values were directly proportional to patient outcomes.
基金supported by grants from the National Key Basic Research Programs(2001CB510007)National Natural Science Foundation of China(30371303).
文摘Systemic lupus erythematosus (SLE) is a typical autoimmune disease involving multiple systems and organs. Ample evidence suggests that autoreactive T cells play a pivotal role in the development of this autoimmune disorder. This study was undertaken to investigate the mechanisms of interaction between antigen presenting cells (APCs) and an autoreactive T cell (ATLI) clone obtained from lupus-prone BXSB mice. ATLI cells, either before or after 7-ray irradiation, were able to activate naive B cells, as determined by B cell proliferation assays. Macrophages from BXSB mice were able to stimulate the proliferation of resting ATL 1 cells at a responder/stimulator (R/S) ratio of 1/2.5. Dendritic cells (DCs) were much more powerful stimulators for ATLI cells on a per cell basis. The T cell stimulating ability ofmacrophages and B cells, but not DCs, was sensitive to T-ray irradiation. Monoclonal antibodies against mouse MHC-Ⅱ and CD4 were able to block DC-mediated stimulation of ATL 1 proliferation, indicating cognate recognition between ATL 1 and APCs. Our data suggest that positive feedback loops involving macrophages, B cells and autoreactive T cells may play a pivotal role in keeping the momentum of autoimmune responses leading to autoimmune diseases.
基金supported by National Science and Technology Major Project granted No.2016ZX01012101
文摘With the introduction of software defined hardware by DARPA Electronics Resurgence Initiative,software definition will be the basic attribute of information system.Benefiting from boundary certainty and algorithm aggregation of domain applications,domain-oriented computing architecture has become the technical direction that considers the high flexibility and efficiency of information system.Aiming at the characteristics of data-intensive computing in different scenarios such as Internet of Things(IoT),big data,artificial intelligence(AI),this paper presents a domain-oriented software defined computing architecture,discusses the hierarchical interconnection structure,hybrid granularity computing element and its computational kernel extraction method,finally proves the flexibility and high efficiency of this architecture by experimental comparison.
基金funded by the National Natural Science Foundation of China(51974355).
文摘Cementing carbonate reservoirs is generally a difficult task.The so-called thixotropic cement slurry has gained considerable attention in this regard as it can help tofix some notable problems.More precisely,it can easilyfill the leakage layer;moreover,its gelling strength can grow rapidly when pumping stops,thereby increasing the resistance to gas channeling,effectively preventing this undesired phenomenon in many cases.High-temperature thixotropic cement slurry systems,however,are still in an early stage of development and additional research is needed to make them a viable option.In the present study,using a self-developed composite high-temperature thixotropic additive as a basis,it is shown that the compressive strength can be adjusted by tuning the proportion of silica sand,the high-temperature retarder,fluid loss additive and dispersant(compatible with the thixotropic additive).According to the tests,the developed high-temperature thixotropic cement slurry system has a 14 d compressive strength of 29.73 MPa at 150°C,and a thickening time of 330 min when the dosage of retarder is 2%.At the same time,the rheological property,water loss,permeability,water separation rate,and settlement stability of the cement slurry system meet the requirements of cementing construction.
基金Supported by National Natural Science Foundtation of China (Grant No. 10771185)
文摘We consider harmonic moments of branching processes in general random environments. For a sequence of square integrable random variables, we give some conditions such that there is a positive constant c that every variable in this sequence belong to Ac or A1c uniformly.
基金Acknowledgements We thank Dr Peter Delves, University College London, for useful comments on the manuscript. The design of the work was approved by local ethical committees of Peking University Health Science Center. The subject's written consent was obtained according to the Declaration of Helsinki. This study was supported by grants from the National Key Basic Research Programs (2007CB512406), "863" Program (2006AA02Z495) and also Natural Science Foundation of China (30371303).
文摘This study was undertaken to investigate whether levels of anti-Saccharomyces cerevisiae mannan antibodies (ASCMA) in human sera, a marker for several autoimmune diseases, correlate with rheumatoid arthritis (RA). ASCMA-IgA, -IgG and -IgM levels were measured with enzyme linked immunosorbent assays (ELISA) in patients with RA (n = 30) and 152 healthy adult controls. ASCMA-IgA prevalence was significantly higher in RA patients (40%) than in healthy subjects (5.3%). A strong correlation between levels of ASCMA-IgA and CRP (r = 0.695; p 〈 0.01) and ESR (r = 0.708; p 〈 0.01) in RA patients was observed. No significant differences in ASCMA-IgG or IgM levels were noted between RA patients and healthy control subjects in the present study. This result differs from previous reports. It remains to be evaluated whether elevated ASCMA-levels are common to all rheumatic disorders.
基金We appreciate the assistance and advice from Professor Dalong Ma from the Department of Immunology, Peking University Health Science Center and thank Hounan Wu, a technician in the Analytic Center of Peking University Health Science Center, for her professional and skilled help in micro-well single cell sorting. This work was supported by the National Natural Science Foundation of China (Grant Nos. 31400736 and 31670947).
文摘Leukocyte differentiation antigens (LDAs) play important roles in the immune system, by serving as surface markers and participating in multiple biological activities, such as recognizing pathogens, mediating membrane signals, interacting with other cells or systems, and regulating cell differentiation and activation. Data mining is a powerful tool used to identify novel LDAs from whole genome. LRRC25 (leucine rich repeat-containing 25) was predicted to have a role in the function of myeloid cells by a large-scale "omics" data analysis. Further experimental validation showed that LRRC25 is highly expressed in primary myeloid cells, such as granulocytes and monocytes, and lowly/intermediately expressed in B cells, but not in T cells and almost all NK cells. It was down-regulated in multiple acute myeloid leukemia (AML) cell lines and bone marrow cells of AML patients and up-regulated after all-trans retinoic acid (ATRA)-mediated granulocytic differentiation in AML cell lines and acute promyelocytic leukemia (APL; AML-M3, FAB classification) cells. Localization analysis showed that LRRC25 is a type I transmembrane molecule. Although ectopic LRRC25 did not promote spontaneous differentiation of NB4 cells, knockdown of LRRC25 by siRNA or shRNA and knockout of LRRC25 by the CRISPR-Cas9 system attenuated ATRA-induced termi- nal granulocytic differentiation, and restoration of LRRC25 in knockout cells could rescue ATRA-induced granulocytic differentiation. Therefore, LRRC25, a potential leukocyte differentiation antigen, is a key regulator of ATRA-induced granulocytic differentiation.
基金the financial support from the National Natural Science Foundation of China (Nos. 52001255, 21901209, 21901210, 22071196, 22007078)Key R&D Program of Shaanxi Province (No. 2021KWZ-18)+2 种基金Aeronautical Science Foundation of China (No. ASFC-2020Z061053001)Fundamental Research Funds for the Central Universities (Nos. 3102019smxy001, 3102019ghxm005)Fellowship from CSC Innovative Team Program (No. CXXM20190099)。
文摘Constitutionally adaptive chemistry of selenium-containing crown ethers(CEs) offers a new platform for controlling/switching the hydration of bolaamphiphile skeletons in water in an effective and simple manner by the virtue of covalent bonding. The adaptive behaviour of the macrocyclic bolaamphiphiles(transformations between C7SeBola and C7SeOBola) in response to redox environment was found to be a decisive factor.
基金This study was supported by grants from the National Key Basic Research Programs(2007CB5124062009)+1 种基金“863”Program(2006AA02Z495)also Natural Science Foundation of China(30371303).
文摘Inbred strains of mice and rats are widely used in preclinical investigations evaluating the effectiveness of glycan-based biomecines,however,the glycan specificity repertoires of serum Abs in rodents have not been fully characterized.In the present study,serum antibodies in naïve mice and rats of different inbred strains were analyzed for specificity against 4 representative carbohydrate structures including PGA(1,4-linkeda-D-galactopyranosyluronic acids),b-glucan,mannan anda-glucan(dextran).Mannan was not recognized by serum Abs from any of the mouse and rat strains.Serum IgM in naïve F344,BN and Lewis rats recognized PGA andb-glucan and,less strongly,dextran.High titer circulating IgM against PGA were found in mice of BALB/c,C57BL/6,C3H/NeH and BXSB strains.C3H/NeH was the only strain which also produced low titer IgM against β-glucan and dextran.Age-related production of high titer IgM,IgA and IgG Abs against β-glucan was observed in BXSB mice.Intraperitoneal immunization of BALB/c and C57BL/6 mice with β-glucan elicited strong IgM responses,while immunization with PGA also led to an increase of anti-PGA IgM Ab titers.These results provide useful information on the characteristics of glycan-specific natural antibody repertoires in rodents.
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.
基金financial support from the National Natural Science Foundation of China(Nos.21901210,21901209,22071196,22007078)Natural Science Foundation of Shaanxi Province of China(No.2019JQ-626)+3 种基金Postdoctoral Innovative Talents Supporting Project of China(No.BX20180255)Key R&D Program of Shaanxi Province(Nos.2019KW-031,2019KW-038)Fundamental Research Funds for the Central Universities(Nos.3102019smxy001,3102018zy051,3102018jcc007,3102017OQD045,3102017OQD040,3102017OQD115,3102019ghxm005)State Key Laboratory of Solidification Processing in NPU(No.SKLSP201817)。
文摘A novel diselenide-containing crown ether(BC7Se_(2))was fabricated,which can polymerize to form cyclic oligomers through intermolecular dynamic covalent reaction by irradiation of visible light.The size and distribution of oligomers are related to the monomer concentration.The decomposition reaction of oligomers is controlled by topology and solvents.Furthermore,potassium cation can inhibit the polymerization of BC7Se_(2)and accelerate the decomposition of oligomers.