Publications by authors named "S L Peng"

5,256 Publications

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Nanoscale mapping of electric polarizability in a heterogeneous dielectric material with surface irregularities.

Nanotechnology 2021 Sep 15. Epub 2021 Sep 15.

Electrical Engineering, Tsinghua University, State Key Laboratory of Power System, Department of, Electrical Engineering, Beijing, 100084, CHINA.

Nanoscale mapping of electric polarizability in a heterogeneous dielectric material with surface irregularities is of scientific and technical significance, but remains challenging. Here, we present an approach based on intermodulation electrostatic force microscopy (EFM) in conjunction with finite element computation for precise and high-resolution mapping of polarizability in dielectric materials. Instead of using electrostatic force in conventional quantitative EFM approaches, the force gradient is acquired to achieve an unprecedented spatial resolution. In the meantime, the finite element model is applied to eliminate the interference from the heterogeneity and surface irregularity of the sample. This approach directly reveals the high polarization ability of the amorphous region in a ferroelectric, semi-crystalline polymer with significant surface roughness, i.e., poly (vinylidene fluoride-co-chlorotrifluoroethylene), in which the result is consistent with the predicted data in the latest research. This work presenting a quantitative approach to nanoscale mapping of electric polarizability with unprecedented spatial resolution may help to reveal the complex property-structure correlation in heterogeneous dielectric materials.
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http://dx.doi.org/10.1088/1361-6528/ac26ffDOI Listing
September 2021

Anaplastic Thyroid Cancer Successfully Treated With Radiation and Immunotherapy: A Case Report.

AACE Clin Case Rep 2021 Sep-Oct;7(5):299-302. Epub 2021 Mar 13.

Department of Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.

Objective: Anaplastic thyroid cancer (ATC) is a rare thyroid cancer subtype with a devastating prognosis. Novel treatment strategies are under investigation to improve the survival of patients with ATC.

Methods: We present a case of recurrent ATC treated with a combination of radiation therapy (RT) and pembrolizumab, a programmed death-1 inhibitor, with a durable complete response.

Results: A 63-year-old woman underwent total thyroidectomy and left neck lymph node dissection and was diagnosed with papillary carcinoma in December, 2017. She received radioiodine in April, 2018. However, a left neck mass was noted in April, 2018 with biopsy demonstrating ATC with 95% positivity for programmed death-ligand 1 immunostaining. Positron emission tomography showed fluorodeoxyglucose uptake in the left thyroid bed and multiple lymph nodes in the left retropharyngeal, left neck, and right upper paratracheal areas. Hypofractionated RT for the recurrent areas was initiated in August,2018, and concomitant pembrolizumab was given 2 days after RT. A total of 10 cycles of pembrolizumab (2 mg/kg) were given every 3 weeks. The computed tomography scan after completion of RT and 3 cycles of pembrolizumab showed shrinkage of the neck lymph nodes. The serial follow-up computed tomography scans showed further shrinkage of the lymph nodes, and there was no recurrence of ATC as of October, 2020.

Conclusion: We describe an ATC case successfully treated with a combination of RT and pembrolizumab with a durable response of 26 months and acceptable toxicities. This result warrants further investigation of this combination regimen in the treatment of ATC.
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http://dx.doi.org/10.1016/j.aace.2021.03.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8426608PMC
March 2021

Control of Spontaneous HPV16 E6/E7 Expressing Oral Cancer in HLA-A2 (AAD) Transgenic Mice with Therapeutic HPV DNA Vaccine.

J Biomed Sci 2021 Sep 13;28(1):63. Epub 2021 Sep 13.

Department of Pathology, Johns Hopkins University, CRB II, 1550 Orleans St, Baltimore, MD, 21287, USA.

Background: Human Papillomavirus type 16 (HPV16) has been associated with a subset of head and neck cancers. Two HPV encoded oncogenic proteins, E6 and E7, are important for the malignant progression of HPV-associated cancers. A spontaneous HPV16 E6/E7-expressing oral tumor model in human HLA-A2 (AAD) transgenic mice will be important for the development of therapeutic HPV vaccines for the control of HPV-associated head and neck cancers.

Methods: In the current studies, we characterized the HLA-A2 restricted HPV16 E7-specific CD8 + T cell mediated immune responses in the HLA-A2 (AAD) transgenic mice using a therapeutic naked DNA vaccine encoding calreticulin (CRT) linked to a mutated E7(N53S). We also employed oncogenic DNA plasmids that encoded HPV16E6/E7/Luc, NRas, and sleeping beauty transposase for the transfection into the submucosal of oral cavity of the transgenic mice with electroporation to create a spontaneous oral tumor. Furthermore, we characterized the therapeutic antitumor effects of CRT/E7(N53S) DNA vaccine using the spontaneous HPV16 E6/E7-expressing oral tumor model in HLA-A2 (AAD) transgenic mice.

Results: We found that CRT/E7(N53S) DNA vaccine primarily generated human HPV16 E7 peptide (aa11-20) specific CD8 + T cells, as compared to the wild-type CRT/E7 vaccine, which primarily generated murine H-2D restricted E7 peptide (aa49-57) specific CD8 + T cell responses. We also observed transfection of the oncogenic DNA plasmids with electroporation generated spontaneous oral tumor in all of the injected mice. Additionally, treatment with CRT/E7(N53S) DNA vaccine intramuscularly followed by electroporation resulted in significant antitumor effects against the spontaneous HPV16 E6/E7-expressing oral tumors in HLA-A2 (AAD) transgenic mice.

Conclusions: Taken together, the data indicated that the combination of HPV16 E6/E7-expressing DNA, NRas DNA and DNA encoding sleeping beauty transposase is able to generate spontaneous oral tumor in HLA-A2 (AAD) transgenic mice, which can be successfully controlled by treatment with CRT/E7(N53S) DNA vaccine. The translational potential of our studies are discussed.
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http://dx.doi.org/10.1186/s12929-021-00759-xDOI Listing
September 2021

Enhanced bone regeneration via spatiotemporal and controlled delivery of a genetically engineered BMP-2 in a composite Hydrogel.

Biomaterials 2021 Sep 2;277:121117. Epub 2021 Sep 2.

Department of Spine Surgery and Institute for Orthopaedic Research, Shenzhen People's Hospital, The First Affiliated Hospital of Southern University of Science and Technology, Jinan University Second College of Medicine, Shenzhen Key Laboratory of Musculoskeletal Tissue Reconstruction and Function Restoration, Shenzhen, 518001, China. Electronic address:

Scaffolds functionalized with bone morphogenetic protein-2 (BMP-2) have shown great potential for bone regeneration. However, structural instability and the necessity for supra-physiological dose have thus far limited practical applications for BMP-2. Protein modification and site-specific covalent immobilization of BMP-2 to carrier materials might be optimal strategies to overcome these problems. Here, we report a broadly applicable strategy where the polyhistidine tag-T4 Lysozyme (His6-T4L) was genetically fused at the N-terminus of BMP-2 and used as a protein spacer, which on one hand enhanced protein solubility and stability, and on the other hand mediated site-specific covalent anchoring of BMP-2 upon binding to nickel-chelated nitrilotriacetic acid (Ni-NTA) microparticles (denoted as MPs-His6-T4L-BMP2) to further maximize its rescued activity. We also constructed a novel gelatin-based hydrogel that was crosslinked by transglutaminase (TG) and tannic acid (TA). This hydrogel, when incorporated with MPs-His6-T4L-BMP2, displayed excellent in-situ injectability, thermosensitivity, adhesiveness and improved mechanical properties. The effective loading mode led to a controlled and long-term sustained release of His6-T4L-BMP2, thereby resulting in enhancement of bone regeneration in a critical-sized bone defect. We believe that the protein modification strategy proposed here opens up new route not only for BMP-2 applications, but can be used to inform novel uses for other macromolecules.
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http://dx.doi.org/10.1016/j.biomaterials.2021.121117DOI Listing
September 2021

Multimorbidity, depressive symptoms and disability in activities of daily living amongst middle-aged and older Chinese: Evidence from the China Health and Retirement Longitudinal Study.

J Affect Disord 2021 Aug 31;295:703-710. Epub 2021 Aug 31.

Department of Health Policy and Management, School of Public Health, Peking University, Beijing, 100191, China.. Electronic address:

Background: Given that multimorbidity is strongly associated with disability in activities of daily living (ADL) and the mechanism still remains unclear, this study sought to investigate the mediating effect of depressive symptoms on such association.

Methods: A longitudinal dataset was drawn from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2015), including 3951 adults aged 45 years and above. By sex, logistic regression and mediation analysis (the Karlson, Holm, and Breen Method) were employed.

Results: The presence of multimorbidity was associated with increased odds of having depressive symptoms and developing ADL disability, and depressive symptoms was significantly associated with ADL disability among middle-aged and older women. Mediation analysis illustrated that depressive symptoms accounted for 6.36% of the effect of multimorbidity on ADL disability in women.

Limitations: Results might not generalize to all middle-aged and older Chinese due to missing data on depressive symptoms and ADL.

Conclusions: Multimorbidity increased the likelihood of ADL disability onset partially through depressive symptoms in middle-aged and older women, suggesting that emphasizing mental wellness of females with multimorbidity are necessary to prevent impairments in physical function.
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http://dx.doi.org/10.1016/j.jad.2021.08.072DOI Listing
August 2021
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