A summer-autumn (1994) molecular epidemiological study of enteric adenoviruses (EAds) in stool specimens collected in Wuhan area was conducted by using Digoxigenin-labelled DNA probes specific to EAd40, and EAd41, res...A summer-autumn (1994) molecular epidemiological study of enteric adenoviruses (EAds) in stool specimens collected in Wuhan area was conducted by using Digoxigenin-labelled DNA probes specific to EAd40, and EAd41, respectively.44 of 602 specimens were positive, among which 23 cases were identified as EAd40, 14 were EAd41, infection and 7 were dual infection. The ratio of males to females for the positive specimens was 1. 44. The infection rate of EAd40 and EAd41 each displayed no marked difference in seasons (summer and autumn) and similar age distribution was found between them. All of the two types of EAds in-fections predominated in patients with diarrhea under 3 years old- The results indicated that the Digoxigenin probe could detect DNA quantities as low as 1 pgwith satis factory specificity and the technique can be used for both clinical and ex-perimental purposes.展开更多
New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specif...New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specific molecular species in such systems. In the present study, a molecular probe strategy in combination with tandem electrospray ionization mass spectrometry has been examined using synthetic deuterium-labeled phosphatidylcholine hydroperoxide (PC-OOH/D3) and ethyl-labeled phosphatidylcholine having docosahexaenoic acid side chain (DHA-PC/Et). Administration of a mixture of PC-OOH/D3 and DHA-PC/Et to human blood and human skin surface, followed by extraction and analysis with collision-induced tandem electrospray ionization mass spectrometry demonstrated that metabolites of both molecular probes can be detected simultaneously with strict selectivity. The present method is also found to be useful in tracing chemical changes of the unstable docosahexaenoyl group on the surface of processed fish. The activity of phospholipase A2 can also be assessed using a phospholipid molecular probe with a linoleoyl and a deuteriomethyl group via selective detection of the lyso-phospholipid product by mass spectrometry. The advantage of the present method is that no chromatographic separation is required and analysis can be performed under strictly the same condition for different molecular probes, affording multiple data by one experiment. The present strategy may be useful for tracing time-dependent phenomena in dynamic phospholipid biochemistry, and can be widely used for any biological and food systems.展开更多
The properties of one-photon absorption（OPA）, emission and two-photon absorption（TPA） of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with res...The properties of one-photon absorption（OPA）, emission and two-photon absorption（TPA） of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with response functions.The responsive mechanism is explored. It is found that the calculated OPA and TPA properties are quite consistent with experimental data. Because the intra-molecular charge transfer（ICT） increases upon zinc ion binding, the TPA intensity is enhanced dramatically. According to the model sensor, we design a series of zinc ion probes which differ by conjugation center, acceptor and donor moieties. The properties of OPA, emission and TPA of the designed molecules are calculated at the same computational level. Our results demonstrate that the OPA and emission wavelengths of the designed probes have large red-shifts after zinc ions have been bound. Comparing with the model sensor, the TPA intensities of the designed probes are enhanced significantly and the absorption positions are red-shifted to longer wavelength range. Furthermore, the TPA intensity can be improved greatly upon zinc ion binding due to the increased ICT mechanism. These compounds are potential excellent candidates for two-photon fluorescent zinc ion probes.展开更多
During the past several decades,positron emission tomography（PET） has been one of the rapidly growing areas of medical imaging;particularly,its applications in routine oncological practice have been widely recognize...During the past several decades,positron emission tomography（PET） has been one of the rapidly growing areas of medical imaging;particularly,its applications in routine oncological practice have been widely recognized.At present,^18F-fluorodeoxyglucose（^18F-FDG） is the most broadly used PET probe.However,^18F-FDG also suffers many limitations.Thus,scientists and clinicians are greatly interested in exploring and developing new PET imaging probes with high affinity and specificity.In this review,we briefly summarize the representative PET probes beyond ^18F-FDG that are available for patients imaging in three major clinical areas（oncology,neurology and cardiology）,and we also discuss the feasibility and trends in developing new PET probes for personalized medicine.展开更多
In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cere...In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.展开更多
Precision medicine and personalized therapy are receiving increased attention, and molecular-subtype classification has become crucial in planning therapeutic schedules in clinical practice for patients with breast ca...Precision medicine and personalized therapy are receiving increased attention, and molecular-subtype classification has become crucial in planning therapeutic schedules in clinical practice for patients with breast cancer. Human epidermal growth factor receptor 2(HER2) is associated with high-grade breast tumors, high rates of lymph-node involvement, high risk of recurrence, and high resistance to general chemotherapy. Analysis of HER2 expression is highly important for doctors to identify patients who can benefit from trastuzumab therapy and monitor the response and efficacy of treatment. In recent years, significant efforts have been devoted to achieving specific and noninvasive HER2-positive breast cancer imaging in vivo. In this work, we reviewed existing literature on HER2 imaging in the past decade and summarized the studies from different points of view, such as imaging modalities and HER2-specific probes. We aimed to improve the understanding on the translational process in molecular imaging for HER2 breast cancer.展开更多
There is a growing realization that cell-to-cell variations in gene expression have importantbiological consequences underlying phenotype diversity and cell fate. Although analytical toolsfor measuring gene expression...There is a growing realization that cell-to-cell variations in gene expression have importantbiological consequences underlying phenotype diversity and cell fate. Although analytical toolsfor measuring gene expression, such as DNA microarrays, reverse-transcriptase PCR and in situhybridization have been widely utilized to discover the role of genetic variations in governingcellular behavior, these methods are performed in cell lysates and/or on fixed cells, and thereforelack the ability to provide comprehensive spatial-dynamic information on gene expression. Thishas invoked the recent development of molecular imaging strategies capable of illuminatingthe distribution and dynamics of RNA molecules in living cells. In this review, we describe aclass of molecular imaging probes known as molecular beacons (MBs), which have increasinglybecome the probe of choice for imaging RNA in living cells. In addition, we present the majorchallenges that can limit the ability of MBs to provide accurate measurements of RNA, anddiscuss efforts that have been made to overcome these challenges. It is envisioned that withcontinued refinement of the MB design, MBs will eventually become an indispensable tool foranalyzing gene expression in biology and medicine.展开更多
Cost effective patterning based on scanning probe nanolithography(SPL)has the potential for electronic and optical nano-device manufacturing and other nanotechnological applications.One of the fundamental advantages o...Cost effective patterning based on scanning probe nanolithography(SPL)has the potential for electronic and optical nano-device manufacturing and other nanotechnological applications.One of the fundamental advantages of SPL is its capability for patterning and imaging employing the same probe.This is achieved with self-sensing and self-actuating cantilevers,also known as‘active'cantilevers.Here we used active cantilevers to demonstrate a novel path towards single digit nanoscale patterning by employing a low energy(<100 eV)electron exposure to thin films of molecular resist.By tuning the electron energies to the lithographically relevant chemical resist transformations,the interaction volumes can be highly localized.This method allows for greater control over spatially confined lithography and enhances sensitivity.We found that at low electron energies,the exposure in ambient conditions required approximately 10 electrons per single calixarene molecule to induce a crosslinking event.The sensitivity was 80-times greater than a classical electron beam exposure at 30 keV.By operating the electro-exposure process in ambient conditions a novel lithographic reaction scheme based on a direct ablation of resist material(positive tone)is presented.展开更多
Protein folding involves the aminoacid sequence to come forth and form an energy minimized structure.Recently molecular crowding leading to increase in viscosity is said to be one of the major concerns affecting prote...Protein folding involves the aminoacid sequence to come forth and form an energy minimized structure.Recently molecular crowding leading to increase in viscosity is said to be one of the major concerns affecting protein folding.Many external fluorescent probes are used to detect such increases in viscosity.Since most of the protein sequences contain L-Phe and L-Trp,in this study we have used these aminoacids as probes to detect changes in viscosity.This study will help to advance the knowledge on molecular crowding effects in protein folding.展开更多
In this paper the results of dynamic NMR studies on ethylmethylamino-tertiary-butyl-phenylborane (EMABPB) with or without light are reported. The NMR data were recorded on a Bruker 400 MHz NMR equipped with our custom...In this paper the results of dynamic NMR studies on ethylmethylamino-tertiary-butyl-phenylborane (EMABPB) with or without light are reported. The NMR data were recorded on a Bruker 400 MHz NMR equipped with our custom-made optical probe and with our custom-made 450 watts (W) monochromatic light sources. The molecular photochemistry including twisted intramolecular charge-transfer-excited-state (TICT) of the EMABPB in several solvents has been investigated. These results indicate that the aminoborane demonstrates multiple configurations in CD3Cl and CD2Cl2 resulting in the shifts of the signals of the alkyl groups on the nitrogen and boron. This indicates that there are some time-dependent changes at constant temperature over the irradiation interval. At ﹣60°C and the presence of light (λ = 265 nm), we observed a large change in the populations of the two sites, and this by itself indicates a modification in the rotation around the boron nitrogen bond in the excited state. By considering the existence of the TICT state, many important energy technologies may be developed with higher efficiency by controlling the back-electron transfer processes.展开更多
文摘A summer-autumn (1994) molecular epidemiological study of enteric adenoviruses (EAds) in stool specimens collected in Wuhan area was conducted by using Digoxigenin-labelled DNA probes specific to EAd40, and EAd41, respectively.44 of 602 specimens were positive, among which 23 cases were identified as EAd40, 14 were EAd41, infection and 7 were dual infection. The ratio of males to females for the positive specimens was 1. 44. The infection rate of EAd40 and EAd41 each displayed no marked difference in seasons (summer and autumn) and similar age distribution was found between them. All of the two types of EAds in-fections predominated in patients with diarrhea under 3 years old- The results indicated that the Digoxigenin probe could detect DNA quantities as low as 1 pgwith satis factory specificity and the technique can be used for both clinical and ex-perimental purposes.
文摘New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specific molecular species in such systems. In the present study, a molecular probe strategy in combination with tandem electrospray ionization mass spectrometry has been examined using synthetic deuterium-labeled phosphatidylcholine hydroperoxide (PC-OOH/D3) and ethyl-labeled phosphatidylcholine having docosahexaenoic acid side chain (DHA-PC/Et). Administration of a mixture of PC-OOH/D3 and DHA-PC/Et to human blood and human skin surface, followed by extraction and analysis with collision-induced tandem electrospray ionization mass spectrometry demonstrated that metabolites of both molecular probes can be detected simultaneously with strict selectivity. The present method is also found to be useful in tracing chemical changes of the unstable docosahexaenoyl group on the surface of processed fish. The activity of phospholipase A2 can also be assessed using a phospholipid molecular probe with a linoleoyl and a deuteriomethyl group via selective detection of the lyso-phospholipid product by mass spectrometry. The advantage of the present method is that no chromatographic separation is required and analysis can be performed under strictly the same condition for different molecular probes, affording multiple data by one experiment. The present strategy may be useful for tracing time-dependent phenomena in dynamic phospholipid biochemistry, and can be widely used for any biological and food systems.
基金Project supported by the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2014AM026)the National Natural Science Foundation of China(Grant Nos.11374195 and 11404193)the Taishan Scholar Project of Shandong Province,China
文摘The properties of one-photon absorption（OPA）, emission and two-photon absorption（TPA） of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with response functions.The responsive mechanism is explored. It is found that the calculated OPA and TPA properties are quite consistent with experimental data. Because the intra-molecular charge transfer（ICT） increases upon zinc ion binding, the TPA intensity is enhanced dramatically. According to the model sensor, we design a series of zinc ion probes which differ by conjugation center, acceptor and donor moieties. The properties of OPA, emission and TPA of the designed molecules are calculated at the same computational level. Our results demonstrate that the OPA and emission wavelengths of the designed probes have large red-shifts after zinc ions have been bound. Comparing with the model sensor, the TPA intensities of the designed probes are enhanced significantly and the absorption positions are red-shifted to longer wavelength range. Furthermore, the TPA intensity can be improved greatly upon zinc ion binding due to the increased ICT mechanism. These compounds are potential excellent candidates for two-photon fluorescent zinc ion probes.
文摘During the past several decades,positron emission tomography（PET） has been one of the rapidly growing areas of medical imaging;particularly,its applications in routine oncological practice have been widely recognized.At present,^18F-fluorodeoxyglucose（^18F-FDG） is the most broadly used PET probe.However,^18F-FDG also suffers many limitations.Thus,scientists and clinicians are greatly interested in exploring and developing new PET imaging probes with high affinity and specificity.In this review,we briefly summarize the representative PET probes beyond ^18F-FDG that are available for patients imaging in three major clinical areas（oncology,neurology and cardiology）,and we also discuss the feasibility and trends in developing new PET probes for personalized medicine.
基金supported by the National Natural Science Foundation of China,No.81730050(to WH).
文摘In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.
基金supported by National Natural Science Foundation of China(Grant No.81202795)China Postdoctoral Science Foundation(Grant No.2015M571271)
文摘Precision medicine and personalized therapy are receiving increased attention, and molecular-subtype classification has become crucial in planning therapeutic schedules in clinical practice for patients with breast cancer. Human epidermal growth factor receptor 2(HER2) is associated with high-grade breast tumors, high rates of lymph-node involvement, high risk of recurrence, and high resistance to general chemotherapy. Analysis of HER2 expression is highly important for doctors to identify patients who can benefit from trastuzumab therapy and monitor the response and efficacy of treatment. In recent years, significant efforts have been devoted to achieving specific and noninvasive HER2-positive breast cancer imaging in vivo. In this work, we reviewed existing literature on HER2 imaging in the past decade and summarized the studies from different points of view, such as imaging modalities and HER2-specific probes. We aimed to improve the understanding on the translational process in molecular imaging for HER2 breast cancer.
基金the National Institutes of Health(NCI)R21 CA116102 and R21 CA125088the National Science Foundation BES-0616031,and the American Cancer Society RSG-07-005-01.
文摘There is a growing realization that cell-to-cell variations in gene expression have importantbiological consequences underlying phenotype diversity and cell fate. Although analytical toolsfor measuring gene expression, such as DNA microarrays, reverse-transcriptase PCR and in situhybridization have been widely utilized to discover the role of genetic variations in governingcellular behavior, these methods are performed in cell lysates and/or on fixed cells, and thereforelack the ability to provide comprehensive spatial-dynamic information on gene expression. Thishas invoked the recent development of molecular imaging strategies capable of illuminatingthe distribution and dynamics of RNA molecules in living cells. In this review, we describe aclass of molecular imaging probes known as molecular beacons (MBs), which have increasinglybecome the probe of choice for imaging RNA in living cells. In addition, we present the majorchallenges that can limit the ability of MBs to provide accurate measurements of RNA, anddiscuss efforts that have been made to overcome these challenges. It is envisioned that withcontinued refinement of the MB design, MBs will eventually become an indispensable tool foranalyzing gene expression in biology and medicine.
文摘Cost effective patterning based on scanning probe nanolithography(SPL)has the potential for electronic and optical nano-device manufacturing and other nanotechnological applications.One of the fundamental advantages of SPL is its capability for patterning and imaging employing the same probe.This is achieved with self-sensing and self-actuating cantilevers,also known as‘active'cantilevers.Here we used active cantilevers to demonstrate a novel path towards single digit nanoscale patterning by employing a low energy(<100 eV)electron exposure to thin films of molecular resist.By tuning the electron energies to the lithographically relevant chemical resist transformations,the interaction volumes can be highly localized.This method allows for greater control over spatially confined lithography and enhances sensitivity.We found that at low electron energies,the exposure in ambient conditions required approximately 10 electrons per single calixarene molecule to induce a crosslinking event.The sensitivity was 80-times greater than a classical electron beam exposure at 30 keV.By operating the electro-exposure process in ambient conditions a novel lithographic reaction scheme based on a direct ablation of resist material(positive tone)is presented.
文摘Protein folding involves the aminoacid sequence to come forth and form an energy minimized structure.Recently molecular crowding leading to increase in viscosity is said to be one of the major concerns affecting protein folding.Many external fluorescent probes are used to detect such increases in viscosity.Since most of the protein sequences contain L-Phe and L-Trp,in this study we have used these aminoacids as probes to detect changes in viscosity.This study will help to advance the knowledge on molecular crowding effects in protein folding.
文摘In this paper the results of dynamic NMR studies on ethylmethylamino-tertiary-butyl-phenylborane (EMABPB) with or without light are reported. The NMR data were recorded on a Bruker 400 MHz NMR equipped with our custom-made optical probe and with our custom-made 450 watts (W) monochromatic light sources. The molecular photochemistry including twisted intramolecular charge-transfer-excited-state (TICT) of the EMABPB in several solvents has been investigated. These results indicate that the aminoborane demonstrates multiple configurations in CD3Cl and CD2Cl2 resulting in the shifts of the signals of the alkyl groups on the nitrogen and boron. This indicates that there are some time-dependent changes at constant temperature over the irradiation interval. At ﹣60°C and the presence of light (λ = 265 nm), we observed a large change in the populations of the two sites, and this by itself indicates a modification in the rotation around the boron nitrogen bond in the excited state. By considering the existence of the TICT state, many important energy technologies may be developed with higher efficiency by controlling the back-electron transfer processes.
