130 research outputs found

    Development of whole-body tissue clearing methods facilitates the cellular mapping of organisms

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    Chemotherapy-induced functional brain abnormality in colorectal cancer patients: a resting‐state functional magnetic resonance imaging study

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    IntroductionChemotherapy-induced cognitive impairment (i.e., “chemobrain”) is a common neurotoxic side-effect experienced by many cancer survivors who undergone chemotherapy. However, the central mechanism underlying chemotherapy-related cognitive impairment is still unclear. The purpose of this study was to investigate the changes of intrinsic brain activity and their associations with cognitive impairment in colorectal cancer (CRC) patients after chemotherapy.MethodsResting‐state functional magnetic resonance imaging data of 29 CRC patients following chemotherapy and 29 matched healthy controls (HCs) were collected in this study, as well as cognitive test data including Mini Mental State Exam (MMSE), Montreal Cognitive Assessment (MoCA) and Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog). The measure of fractional amplitude of low-frequency fluctuation (fALFF) was calculated and compared between groups. The correlations between the fALFF of impaired brain region and cognitive performance were also analyzed.ResultsCompared with HCs, CRC patients following chemotherapy showed decreased fALFF values in the left anterior cingulate gyrus (ACG) and middle frontal gyrus, as well as increased fALFF values in the left superior frontal gyrus (orbital part) and middle occipital gyrus. Moreover, positive associations were identified between fALFF values of the left ACG and the total scores of MMSE, MoCA and FACT-Cog in the patient group.ConclusionThese findings indicated that CRC patients after chemotherapy had decreased intrinsic brain activity in the left ACG, which might be vulnerable to the neurotoxic side-effect of chemotherapeutic drugs and related to chemotherapy-induced cognitive impairment

    PSR J1926-0652: A Pulsar with Interesting Emission Properties Discovered at FAST

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    We describe PSR J1926-0652, a pulsar recently discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Using sensitive single-pulse detections from FAST and long-term timing observations from the Parkes 64-m radio telescope, we probed phenomena on both long and short time scales. The FAST observations covered a wide frequency range from 270 to 800 MHz, enabling individual pulses to be studied in detail. The pulsar exhibits at least four profile components, short-term nulling lasting from 4 to 450 pulses, complex subpulse drifting behaviours and intermittency on scales of tens of minutes. While the average band spacing P3 is relatively constant across different bursts and components, significant variations in the separation of adjacent bands are seen, especially near the beginning and end of a burst. Band shapes and slopes are quite variable, especially for the trailing components and for the shorter bursts. We show that for each burst the last detectable pulse prior to emission ceasing has different properties compared to other pulses. These complexities pose challenges for the classic carousel-type models.Comment: 13pages with 12 figure

    CRAFTS for Fast Radio Bursts : extending the dispersion-fluence relation with new FRBs detected by FAST

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    We report three new FRBs discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST), namely FRB 181017.J0036+11, FRB 181118, and FRB 181130, through the Commensal Radio Astronomy FAST Survey (CRAFTS). Together with FRB 181123, which was reported earlier, all four FAST-discovered FRBs share the same characteristics of low fluence (1000 pc cm(-3)), consistent with the anticorrelation between DM and fluence of the entire FRB population. FRB 181118 and FRB 181130 exhibit band-limited features. FRB 181130 is prominently scattered (tau(s) 8 ms) at 1.25 GHz. FRB 181017.J0036+11 has full-bandwidth emission with a fluence of 0.042 Jy ms, which is one of the faintest FRB sources detected so far. CRAFTS has started to build a new sample of FRBs that fills the region for more distant and fainter FRBs in the fluence-DME diagram, previously out of reach of other surveys. The implied all-sky event rate of FRBs is 1.24(-0.90)(+1.94) x 5 sky(-1) day(-1) at the 95% confidence interval above 0.0146 Jy ms. We also demonstrate here that the probability density function of CRAFTS FRB detections is sensitive to the assumed intrinsic FRB luminosity function and cosmological evolution, which may be further constrained with more discoveries

    Tissue Clearing and Deep Imaging of the Kidney Using Confocal and Two-Photon Microscopy

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    Microscopic and macroscopic evaluation of biological tissues in three dimensions is becoming increasingly popular. This trend is coincident with the emergence of numerous tissue clearing strategies, and advancements in confocal and two-photon microscopy, enabling the study of intact organs and systems down to cellular and sub-cellular resolution. In this chapter, we describe a wholemount immunofluorescence technique for labeling structures in renal tissue. This technique combined with solvent-based tissue clearing and confocal imaging, with or without two-photon excitation, provides greater structural information than traditional sectioning and staining alone. Given the addition of paraffin embedding to our method, this hybrid protocol offers a powerful approach to combine confocal or two-photon findings with histological and further immunofluorescent analysis within the same tissue

    CRAFTS for Fast Radio Bursts Extending the dispersion-fluence relation with new FRBs detected by FAST

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    We report three new FRBs discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST), namely FRB 181017.J0036+11, FRB 181118 and FRB 181130, through the Commensal Radio Astronomy FAST Survey (CRAFTS). Together with FRB 181123 that was reported earlier, all four FAST-discovered FRBs share the same characteristics of low fluence (\leq0.2 Jy ms) and high dispersion measure (DM, >1000>1000 \dmu), consistent with the anti-correlation between DM and fluence of the entire FRB population. FRB 181118 and FRB 181130 exhibit band-limited features. FRB 181130 is prominently scattered (τs8\tau_s\simeq8 ms) at 1.25 GHz. FRB 181017.J0036+11 has full-bandwidth emission with a fluence of 0.042 Jy ms, which is one of the faintest FRB sources detected so far. CRAFTS starts to built a new sample of FRBs that fills the region for more distant and fainter FRBs in the fluence-DME\rm DM_E diagram, previously out of reach of other surveys. The implied all sky event rate of FRBs is 1.240.90+1.94×1051.24^{+1.94}_{-0.90} \times 10^5 sky1^{-1} day1^{-1} at the 95%95\% confidence interval above 0.0146 Jy ms. We also demonstrate here that the probability density function of CRAFTS FRB detections is sensitive to the assumed intrinsic FRB luminosity function and cosmological evolution, which may be further constrained with more discoveries.Comment: 9 Pages, 4 Plots and 1 Table. The Astrophysical Journal Letter Accepte

    Gold nanoprisms as a hybrid in vivo cancer theranostic platform for in situ photoacoustic imaging, angiography, and localized hyperthermia

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    The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody (breast cancer-associated antigen 1 (Brcaa1) monoclonal antibody)- and peptide (RGD)-functionalized gold nanoprisms (AuNprs) were used as a combinatorial methodology for in situ photoacoustic imaging, angiography, and localized hyperthermia using orthotopic and subcutaneous murine gastric carcinoma models. RGD-conjugated PEGylated AuNprs are available for tumor angiography, and Brcaa1 monoclonal antibody-conjugated PEGylated AuNprs are used for targeting and for in situ imaging of gastric carcinoma in orthotopic tumor models. In situ photoacoustic imaging allowed for anatomical and functional imaging at the tumor site. In vivo tumor angiography imaging showed enhancement of the photoacoustic signal in a time-dependent manner. Furthermore, photoacoustic imaging demonstrated that tumor vessels were clearly damaged after localized hyperthermia. This is the first proof-of-concept using two AuNprs probes as highly sensitive contrasts and therapeutic agents for in situ tumor detection and inhibition. These smart antibody/peptide AuNprs can be used as an efficient nanotheranostic platform for in vivo tumor detection with high sensitivity, as well as for tumor targeting therapy, which, with a single-dose injection, results in tumor size reduction and increases mice survival after localized hyperthermia treatment.National Basic Research Program of China (No. 2015CB931802)National Natural Science Foundation (China) (Nos. 81225010, 81327002, 31170961, 20771075, and 20803040)National High-Tech R&D Plan of China (No. 2014AA020700)Shanghai Science and Technology Fund (Nos. 13NM1401500 and 15DZ2252000
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