Browsing by Author "Lu, Wei"

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    A Comprehensive Study of Black Phosphorus-Graphite Composite Anodes and HEMM Synthesis Conditions for Improved Cycle Stability
    (IOP, 2019) Shin, Hosop; Zhang, Jianyu; Lu, Wei; Mechanical and Energy Engineering, School of Engineering and Technology
    Black phosphorus (BP) is a high capacity anode material and has been synthesized with different carbon materials to mitigate volume changes during lithiation/delithiation. There is a large discrepancy in cycle stability of phosphorus-carbon materials in the literature, and factors affecting cycle performance are not well elucidated. In this study, the electrochemical performance of a black phosphorus-graphite (BP-G) composite anode material with regards to (1) material composition, (2) electrolyte additive, (3) ballmilling synthesis conditions, and (4) electrode loading is thoroughly investigated. In particular, this study reveals how ballmilling synthesis conditions correlate to electrochemical performance. Results show that the main contributors to cycle stability of BP-G composites are material composition and electrode loading, while first cycle efficiency and reversible capacity are strongly dependent on ballmilling synthetic conditions. Composition control is the most effective way to mitigate the volume change-induced mechanical degradation of BP-G composites, while ballmilling processing optimization is the main contributor to BP activation in BP-G composites, improving reversible capacity and first cycle efficiency. We thereby propose an optimized, HEMM-based synthetic route for improved BP-G materials. This study provides a comprehensive understanding of BP-G electrochemical performance and the correlation to HEMM synthesis conditions.
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    Diminished Immune Surveillance during Histologic Progression of Intraductal Papillary Mucinous Neoplasms Offers a Therapeutic Opportunity for Cancer Interception
    (American Association for Cancer Research, 2022) Hernandez, Sharia; Parra, Edwin Roger; Uraoka, Naohiro; Tang, Ximing; Shen, Yu; Qiao, Wei; Jiang, Mei; Zhang, Shanyu; Mino, Barbara; Lu, Wei; Pandurengan, Renganayaki; Haymaker, Cara; Affolter, Kajsa; Scaife, Courtney L.; Yip-Schneider, Michele; Schmidt, C. Max; Firpo, Matthew A.; Mulvihill, Sean J.; Koay, Eugene J.; Wang, Huamin; Wistuba, Ignacio I.; Maitra, Anirban; Solis, Luisa M.; Sen, Subrata; Surgery, School of Medicine
    Purpose: Intraductal papillary mucinous neoplasms (IPMN) are bona fide precursors to pancreatic ductal adenocarcinoma (PDAC). While genomic alterations during multistep IPMN progression have been well cataloged, the accompanying changes within the tumor immune microenvironment (TIME) have not been comprehensively studied. Herein, we investigated TIME-related alterations during IPMN progression, using multiplex immunofluorescence (mIF) coupled with high-resolution image analyses. Experimental design: Two sets of formalin-fixed, paraffin-embedded tissue samples from surgically resected IPMNs were analyzed. The training set of 30 samples consisted of 11 low-grade IPMN (LG-IPMN), 17 high-grade IPMN (HG-IPMN), and 2 IPMN with PDAC, while a validation set of 93 samples comprised of 55 LG-IPMN and 38 HG-IPMN. The training set was analyzed with two panels of immuno-oncology-related biomarkers, while the validation set was analyzed with a subset of markers found significantly altered in the training set. Results: Cell types indicative of enhanced immune surveillance, including cytotoxic and memory T cells, and antigen-experienced T cells and B cells, were all found at higher densities within isolated LG-IPMNs compared with HG-IPMNs. Notably, the TIME of LG-IPMNs that had progressed at the time of surgical resection (progressor LGD) resembled that of the synchronous HG-IPMNs, underscoring that attenuated immune surveillance occurs even in LG-IPMNs destined for progression. Conclusions: Our findings provide a basis for interception of cystic neoplasia to PDAC, through maintenance of sustained immune surveillance using vaccines and other prevention approaches.
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    Focused Ultrasonic Propulsion of Kidney Stones
    (Mary Ann Liebert, Inc., 2013-12-09) Sorensen, Mathew D.; Bailey, Michael R.; Hsi, Ryan S.; Cunitz, Bryan W.; Simon, Julianna; Wang, Yak-Nam; Dunmire, Barbrina L.; Paun, Marla; Starr, Frank; Lu, Wei; Evan, Andrew P.; Harper, Jonathan D.; Anatomy and Cell Biology, School of Medicine
    Introduction: Our research group is studying a noninvasive transcutaneous ultrasound device to expel small kidney stones or residual post-treatment stone fragments from the kidney.1-3 The purpose of this study was to evaluate the efficacy and safety of ultrasonic propulsion in a live porcine model. Materials and Methods: In domestic female swine (50-60 kg), human stones (calcium oxalate monohydrate) and metalized glass beads (2-8 mm) were ureteroscopically implanted.4 Target stones and beads were placed in the lower half of the kidney and a reference bead was placed in the upper pole. Ultrasonic propulsion was achieved through a single ultrasound system that allowed targeting, stone propulsion, and ultrasound imaging using a Philips HDI C5-2 commercial imaging transducer and a Verasonics diagnostic ultrasound platform. Stone propulsion was achieved through the delivery of 1-second bursts of focused, ultrasound pulses, which consist of 250 finely focused pulses 0.1 milliseconds in duration. Stone propulsion was then observed using fluoroscopy, ultrasound, and visually with the ureteroscope. The kidneys were then perfusion-fixed with glutaraldehyde, embedded in paraffin, sectioned, and stained. Samples were histologically scored for injury by a blinded independent expert. Using the same pulsing scheme, while varying acoustic intensities, an injury threshold and patterns of injury were determined in additional pigs.5,6 Results: Stones were successfully implanted in 14 kidneys. Overall, 17 of 26 (65)% stones/beads were moved the entire distance to the renal pelvis, ureteropelvic junction (UPJ), or proximal ureter. The average procedure time for successfully repositioned stones was 14.2±7.9 minutes with 23±16 push bursts. No gross or histologic damage was identified from the ultrasound propulsion procedure. Under this pulsing scheme, a maximum exposure of 2400 W/cm2 was delivered during each treatment. An intensity threshold of 16,620 W/cm2 was determined at which, above this level, tissue injury consistent with emulsification, necrosis, and hemorrhage appeared to be dose dependent. Conclusions: Ultrasonic propulsion is effective with most stones being relocated to the renal pelvis, UPJ, or proximal ureter in a timely fashion. The procedure appears safe with no evidence of injury. The acoustic intensities delivered at maximum treatment settings are well below the threshold at which injury is observed. The angle and alignment of directional force are the most critical factors determining the efficacy of stone propulsion. We are now pursuing FDA approval for a human feasibility study. No competing financial interests exist. Runtime of video: 5 mins 44 secs.
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