This study introduces the direct electrodeposition of Cu on Ru-Al2O3 layers, which is a promising... more This study introduces the direct electrodeposition of Cu on Ru-Al2O3 layers, which is a promising material to replace Cu seed, and Ta diffusion barrier layers at once. Ru-Al2O3 layers are deposited by atomic layer deposition (ALD), and their compositions are manipulated by varying the cycle numbers of Ru and Al2O3 ALD. The addition of Al2O3 induces the development of nanocrystalline Ru, instead of columnar structure, enhancing the characteristics as a diffusion barrier without losing a role of the seed layer for Cu electrodeposition. The native oxide of Ru is electrochemically eliminated by the coulometric reduction method (CRM) prior to Cu electrodeposition. The influences of both applied potential and the composition of Ru-Al2O3 layer on Cu film properties are clarified. Furthermore, the ability of Ru-Al2O3 layer to inhibit Cu diffusion is assessed, and it is confirmed that Ru-Al2O3 layer perfectly inhibits Cu diffusion during the annealing carried out at the temperature of 550◦C ...
GroupRight is a comprehensive group decision-making platform for simplifying the organization of ... more GroupRight is a comprehensive group decision-making platform for simplifying the organization of event scheduling, task management, and mass communication. Consisting of a website, iOS application and an Android application, GroupRight provides convenient tools for groups of all sizes to improve productivity. Users can quickly create and manage dynamic groups so that each member of the group can contribute to the overall system. Likewise, updates from individuals using GroupRight’s core tools are provided to the entire group to increase each member’s situational awareness.
Introduction: More that 10% of human proteins can be S-palmitoylated, a post-translational modifi... more Introduction: More that 10% of human proteins can be S-palmitoylated, a post-translational modification (PTM) whereby palmitoyl chains are covalently linked to cysteine thiol groups. S-palmitoylation influences protein trafficking, distribution and function. There is no information on the scope of protein S-palmitoylation in the heart, or how this enzyme-mediated reversible PTM is regulated. Hypothesis: S-palmitoylation occurs to a wide spectrum of proteins in cardiomyocytes, and is coordinated by membrane-embedded palmitoylating (DHHC) enzymes. DHHC enzymes are subject to remodeling during chronic hypertension. Methods: We used resin-assisted capture to purify S-palmitoylated proteins from ventricular myocardium of 3 species: human, dog, and rat. We used global unbiased proteomic search to identify S-palmitoylated proteins. We validated DHHC antibodies and used them to monitor protein level and subcellular distribution of native DHHC enzymes in ventricular myocytes. Results: We bui...
Abstract Fused filament fabrication three-dimensional (FFF 3-D) printing is thought to be environ... more Abstract Fused filament fabrication three-dimensional (FFF 3-D) printing is thought to be environmentally sustainable; however, significant amounts of waste can be generated from this technology. One way to improve its sustainability is via distributed recycling of plastics in homes, schools, and libraries to create feedstock filament for printing. Risks from exposures incurred during recycling and reuse of plastics has not been incorporated into life cycle assessments. This study characterized contaminant releases from virgin (unextruded) and recycled plastics from filament production through FFF 3-D printing. Waste polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) plastics were recycled to create filament; virgin PLA, ABS, high and low density polyethylenes, high impact polystyrene, and polypropylene pellets were also extruded into filament. The release of particles and chemicals into school classrooms was evaluated using standard industrial hygiene methodologies. All tasks released particles that contained hazardous metals (e.g., manganese) and with size capable of depositing in the gas exchange region of the lung, i.e., granulation of waste PLA and ABS (667 to 714 nm) and filament making (608 to 711 nm) and FFF 3-D printing (616 to 731 nm) with waste and virgin plastics. All tasks released vapors, including respiratory irritants and potential carcinogens (benzene and formaldehyde), mucus membrane irritants (acetone, xylenes, ethylbenzene, and methyl methacrylate), and asthmagens (styrene, multiple carbonyl compounds). These data are useful for incorporating risks of exposure to hazardous contaminants in future life cycle evaluations to demonstrate the sustainability and circular economy potential of FFF 3-D printing in distributed spaces.
Ag3O was synthesized by jet-milling magnetron-sputtered Ag–Ag2O thin films. Heating the jet-mille... more Ag3O was synthesized by jet-milling magnetron-sputtered Ag–Ag2O thin films. Heating the jet-milled powders in air and N2 from 40 to 148 °C at ambient pressure produced Ag3O-rich powders. The phase composition and unit-cell parameters of the jet-milled powders were measured as a function of temperature with in situ X-ray powder diffraction experiments from −186 to 293 °C. Ag3O was also produced by ball milling and sonicating jet-milled films at ambient conditions. The phase composition, unit-cell parameters, and thermal-reaction rates indicate nonstoichiometric Ag3O was produced from the reaction of metastable, nonstoichiometric Ag2O (cuprite structure) and ccp Ag. The thermal expansion of Ag3O is anisotropic; below 25 °C, the a-axis expansion is about twice the c-axis expansion resulting in a negative slope of c/a(T). The reversal of the sign of c/a(T) near 25 °C is dramatic. The thermal reaction is arrested when the temperature is rapidly increased from ambient to 130 °C. Ag3O is m...
I Ks plays a key role in ventricular-repolarization during high b-adrenergic tone, and is compose... more I Ks plays a key role in ventricular-repolarization during high b-adrenergic tone, and is composed of KCNQ1 (channel component) and KCNE1 (regulatory subunit). Although KCNQ1 and KCNE1 are obligate partners, we showed that they are largely segregated in AVMs: KCNQ1 mostly in cytosolic compartment while KCNE1 on lateral cell surface (LCS). Only a small portion of KCNQ1 appears to overlap with KCNE1 on LCS. To address the above question, we conduct proof-of-principle experiments by expressing fluorescent protein (FP)-tagged KCNQ1 and KCNE1 in COS-7 cells, and track their movements using confocal, TIRF and structured-illumination microscopies. We use a strategy called 'retention-using-selective-hooks' to differentiate how KCNQ1 and KCNE1 traffic after they exit the endoplasmic reticulum (ER). We use proximity-ligation-amplification (PLA) to locate KCNQ1/KCNE1 assemblies in cells. We conduct physiological experiments by in vitro or in vivo expression of FP-tagged KCNQ1 and KCNE1 in AVMs, using adenovirus or AAV9 respectively. We observe bright spots of KCNQ1-GFP moves within the ER network. When reaching cell edge, KCNQ1-GFP appears to bud off ER in vesicles and disappears presumably by fusing with the plasma membrane (PM). Vesicles of KCNE1-dsRed move in the cytoplasm, and often appear to drag KCNQ1-GFP/ER along tracks or carry bright spot of KCNQ1-GFP transiently. When expressed in AVMs, KCNQ1-GFP clusters to the nuclear envelope and along the z-lines and KCNE1-dsRed is detected in vesicles and LCS. KCNQ1-GFP/KCNE1-dsRed assemblies are present on the LCS and in the sub-sarcolemma compartment beneath LCS. We conclude that KCNQ1 and KCNE1 traffic by different routes to PM and assemble once there: KCNQ1 via an ER/SR route while KCNE1 via a vesicular route. KCNE1 appears capable of guiding KCNQ1 to exit ER/SR, facilitating the formation of I Ks channels on cell surface.
A multicore fiber (MCF) based temperature sensor was fabricated and packaged into a stainless-ste... more A multicore fiber (MCF) based temperature sensor was fabricated and packaged into a stainless-steel tube to protect the bare-fiber, and it offers a commercial friendly form factor. The sensor displayed a periodic supermode interference pattern that red-shifts with increasing temperature, which was used to calibrate the sensor. Additionally, an economical photodiode-based interrogator was fabricated from off-the-shelf parts and used to calibrate the sensor in both liquid and gas mediums. The response time to changes in temperature for the MCF sensor was found to be an order of magnitude faster than a thermocouple of identical diameter, 0.09 s compared to >1.0 s, respectively.
Journal of immunology (Baltimore, Md. : 1950), 2018
Indirect acute respiratory distress syndrome (iARDS) is caused by a nonpulmonary inflammatory pro... more Indirect acute respiratory distress syndrome (iARDS) is caused by a nonpulmonary inflammatory process resulting from insults such as nonpulmonary sepsis. Neutrophils are thought to play a significant role in mediating ARDS, with the development of iARDS being characterized by dysregulation and recruitment of activated neutrophils into the lung. Recently, a novel mechanism of microbial killing by neutrophils was identified through the formation of neutrophil extracellular traps (NETs). NETs are composed of large webs of decondensed chromatin released from activated neutrophils into the extracellular space; they are regulated by the enzyme peptidylarginine deiminase 4 (PAD4) through mediation of chromatin decondensation via citrullination of target histones. Components of NETs have been implicated in ARDS. However, it is unknown whether there is any pathological significance of NET formation in ARDS caused indirectly by nonpulmonary insult. We subjectedmice and wild-type mice to a &qu...
In this study, the electroless deposition of copper and silver was investigated on epoxy and sili... more In this study, the electroless deposition of copper and silver was investigated on epoxy and silicon dioxide-based substrates. A cost-efficient, Sn/Ag catalyst was investigated as a replacement for the Sn/Pd catalyst currently used in board technology. The surface of the epoxy based polyhedral oligomeric silsesquioxane (POSS) films was modified by plasma and chemical etching for electroless activation without the creation of a roughened surface. The electroless copper deposited on the modified POSS surface exhibited excellent adhesion when annealed at 180 • C in nitrogen for 90 min or at room temperature for 24 hr. Electroless copper deposition was also demonstrated on oxidized silicon wafers for through silicon via sidewall deposition.
Electroless copper deposition was investigated on epoxy laminate substrates (Isola 185HR) using a... more Electroless copper deposition was investigated on epoxy laminate substrates (Isola 185HR) using a silver-based catalyst, and a nonroughening surface treatment method based on sulfuric acid. The current challenges in electroless copper deposition include (i) high cost of Pd-based catalysts, (ii) deterioration of electrical performance of deposited metal at high frequency due to electron scattering at the roughened surface, and (iii) limited adhesion strength of electroless layers to substrates. We investigated an electroless copper deposition procedure composed of a H 2 SO 4 surface pretreatment, two-step Sn/Ag nano-colloidal catalyst seeding, and immersion in a traditional formaldehyde-containing electroless copper bath. The H 2 SO 4 pretreatment activated the epoxy surface for electroless deposition. Other strong acids did not lead to deposition. The H 2 SO 4 treatment cleaned the substrate and provided the adhesion of the catalyst and electroless copper without increasing the surface roughness. XPS results showed a decrease in the carbonyl groups (C=O), and acid/ester functionalities (O-C=O) at the surface. Adsorbed sulfate on the substrate from the H 2 SO 4 treatment led to Sn(II) sensitization. The tin-silver activation step resulted in Sn(IV) and Ag(0) products in the form of a Sn/Ag nano-colloidal catalyst. The Sn/Ag colloid acted as a catalyst for electroless copper deposition on the epoxy laminate substrates.
This study introduces the direct electrodeposition of Cu on Ru-Al2O3 layers, which is a promising... more This study introduces the direct electrodeposition of Cu on Ru-Al2O3 layers, which is a promising material to replace Cu seed, and Ta diffusion barrier layers at once. Ru-Al2O3 layers are deposited by atomic layer deposition (ALD), and their compositions are manipulated by varying the cycle numbers of Ru and Al2O3 ALD. The addition of Al2O3 induces the development of nanocrystalline Ru, instead of columnar structure, enhancing the characteristics as a diffusion barrier without losing a role of the seed layer for Cu electrodeposition. The native oxide of Ru is electrochemically eliminated by the coulometric reduction method (CRM) prior to Cu electrodeposition. The influences of both applied potential and the composition of Ru-Al2O3 layer on Cu film properties are clarified. Furthermore, the ability of Ru-Al2O3 layer to inhibit Cu diffusion is assessed, and it is confirmed that Ru-Al2O3 layer perfectly inhibits Cu diffusion during the annealing carried out at the temperature of 550◦C ...
GroupRight is a comprehensive group decision-making platform for simplifying the organization of ... more GroupRight is a comprehensive group decision-making platform for simplifying the organization of event scheduling, task management, and mass communication. Consisting of a website, iOS application and an Android application, GroupRight provides convenient tools for groups of all sizes to improve productivity. Users can quickly create and manage dynamic groups so that each member of the group can contribute to the overall system. Likewise, updates from individuals using GroupRight’s core tools are provided to the entire group to increase each member’s situational awareness.
Introduction: More that 10% of human proteins can be S-palmitoylated, a post-translational modifi... more Introduction: More that 10% of human proteins can be S-palmitoylated, a post-translational modification (PTM) whereby palmitoyl chains are covalently linked to cysteine thiol groups. S-palmitoylation influences protein trafficking, distribution and function. There is no information on the scope of protein S-palmitoylation in the heart, or how this enzyme-mediated reversible PTM is regulated. Hypothesis: S-palmitoylation occurs to a wide spectrum of proteins in cardiomyocytes, and is coordinated by membrane-embedded palmitoylating (DHHC) enzymes. DHHC enzymes are subject to remodeling during chronic hypertension. Methods: We used resin-assisted capture to purify S-palmitoylated proteins from ventricular myocardium of 3 species: human, dog, and rat. We used global unbiased proteomic search to identify S-palmitoylated proteins. We validated DHHC antibodies and used them to monitor protein level and subcellular distribution of native DHHC enzymes in ventricular myocytes. Results: We bui...
Abstract Fused filament fabrication three-dimensional (FFF 3-D) printing is thought to be environ... more Abstract Fused filament fabrication three-dimensional (FFF 3-D) printing is thought to be environmentally sustainable; however, significant amounts of waste can be generated from this technology. One way to improve its sustainability is via distributed recycling of plastics in homes, schools, and libraries to create feedstock filament for printing. Risks from exposures incurred during recycling and reuse of plastics has not been incorporated into life cycle assessments. This study characterized contaminant releases from virgin (unextruded) and recycled plastics from filament production through FFF 3-D printing. Waste polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) plastics were recycled to create filament; virgin PLA, ABS, high and low density polyethylenes, high impact polystyrene, and polypropylene pellets were also extruded into filament. The release of particles and chemicals into school classrooms was evaluated using standard industrial hygiene methodologies. All tasks released particles that contained hazardous metals (e.g., manganese) and with size capable of depositing in the gas exchange region of the lung, i.e., granulation of waste PLA and ABS (667 to 714 nm) and filament making (608 to 711 nm) and FFF 3-D printing (616 to 731 nm) with waste and virgin plastics. All tasks released vapors, including respiratory irritants and potential carcinogens (benzene and formaldehyde), mucus membrane irritants (acetone, xylenes, ethylbenzene, and methyl methacrylate), and asthmagens (styrene, multiple carbonyl compounds). These data are useful for incorporating risks of exposure to hazardous contaminants in future life cycle evaluations to demonstrate the sustainability and circular economy potential of FFF 3-D printing in distributed spaces.
Ag3O was synthesized by jet-milling magnetron-sputtered Ag–Ag2O thin films. Heating the jet-mille... more Ag3O was synthesized by jet-milling magnetron-sputtered Ag–Ag2O thin films. Heating the jet-milled powders in air and N2 from 40 to 148 °C at ambient pressure produced Ag3O-rich powders. The phase composition and unit-cell parameters of the jet-milled powders were measured as a function of temperature with in situ X-ray powder diffraction experiments from −186 to 293 °C. Ag3O was also produced by ball milling and sonicating jet-milled films at ambient conditions. The phase composition, unit-cell parameters, and thermal-reaction rates indicate nonstoichiometric Ag3O was produced from the reaction of metastable, nonstoichiometric Ag2O (cuprite structure) and ccp Ag. The thermal expansion of Ag3O is anisotropic; below 25 °C, the a-axis expansion is about twice the c-axis expansion resulting in a negative slope of c/a(T). The reversal of the sign of c/a(T) near 25 °C is dramatic. The thermal reaction is arrested when the temperature is rapidly increased from ambient to 130 °C. Ag3O is m...
I Ks plays a key role in ventricular-repolarization during high b-adrenergic tone, and is compose... more I Ks plays a key role in ventricular-repolarization during high b-adrenergic tone, and is composed of KCNQ1 (channel component) and KCNE1 (regulatory subunit). Although KCNQ1 and KCNE1 are obligate partners, we showed that they are largely segregated in AVMs: KCNQ1 mostly in cytosolic compartment while KCNE1 on lateral cell surface (LCS). Only a small portion of KCNQ1 appears to overlap with KCNE1 on LCS. To address the above question, we conduct proof-of-principle experiments by expressing fluorescent protein (FP)-tagged KCNQ1 and KCNE1 in COS-7 cells, and track their movements using confocal, TIRF and structured-illumination microscopies. We use a strategy called 'retention-using-selective-hooks' to differentiate how KCNQ1 and KCNE1 traffic after they exit the endoplasmic reticulum (ER). We use proximity-ligation-amplification (PLA) to locate KCNQ1/KCNE1 assemblies in cells. We conduct physiological experiments by in vitro or in vivo expression of FP-tagged KCNQ1 and KCNE1 in AVMs, using adenovirus or AAV9 respectively. We observe bright spots of KCNQ1-GFP moves within the ER network. When reaching cell edge, KCNQ1-GFP appears to bud off ER in vesicles and disappears presumably by fusing with the plasma membrane (PM). Vesicles of KCNE1-dsRed move in the cytoplasm, and often appear to drag KCNQ1-GFP/ER along tracks or carry bright spot of KCNQ1-GFP transiently. When expressed in AVMs, KCNQ1-GFP clusters to the nuclear envelope and along the z-lines and KCNE1-dsRed is detected in vesicles and LCS. KCNQ1-GFP/KCNE1-dsRed assemblies are present on the LCS and in the sub-sarcolemma compartment beneath LCS. We conclude that KCNQ1 and KCNE1 traffic by different routes to PM and assemble once there: KCNQ1 via an ER/SR route while KCNE1 via a vesicular route. KCNE1 appears capable of guiding KCNQ1 to exit ER/SR, facilitating the formation of I Ks channels on cell surface.
A multicore fiber (MCF) based temperature sensor was fabricated and packaged into a stainless-ste... more A multicore fiber (MCF) based temperature sensor was fabricated and packaged into a stainless-steel tube to protect the bare-fiber, and it offers a commercial friendly form factor. The sensor displayed a periodic supermode interference pattern that red-shifts with increasing temperature, which was used to calibrate the sensor. Additionally, an economical photodiode-based interrogator was fabricated from off-the-shelf parts and used to calibrate the sensor in both liquid and gas mediums. The response time to changes in temperature for the MCF sensor was found to be an order of magnitude faster than a thermocouple of identical diameter, 0.09 s compared to >1.0 s, respectively.
Journal of immunology (Baltimore, Md. : 1950), 2018
Indirect acute respiratory distress syndrome (iARDS) is caused by a nonpulmonary inflammatory pro... more Indirect acute respiratory distress syndrome (iARDS) is caused by a nonpulmonary inflammatory process resulting from insults such as nonpulmonary sepsis. Neutrophils are thought to play a significant role in mediating ARDS, with the development of iARDS being characterized by dysregulation and recruitment of activated neutrophils into the lung. Recently, a novel mechanism of microbial killing by neutrophils was identified through the formation of neutrophil extracellular traps (NETs). NETs are composed of large webs of decondensed chromatin released from activated neutrophils into the extracellular space; they are regulated by the enzyme peptidylarginine deiminase 4 (PAD4) through mediation of chromatin decondensation via citrullination of target histones. Components of NETs have been implicated in ARDS. However, it is unknown whether there is any pathological significance of NET formation in ARDS caused indirectly by nonpulmonary insult. We subjectedmice and wild-type mice to a &qu...
In this study, the electroless deposition of copper and silver was investigated on epoxy and sili... more In this study, the electroless deposition of copper and silver was investigated on epoxy and silicon dioxide-based substrates. A cost-efficient, Sn/Ag catalyst was investigated as a replacement for the Sn/Pd catalyst currently used in board technology. The surface of the epoxy based polyhedral oligomeric silsesquioxane (POSS) films was modified by plasma and chemical etching for electroless activation without the creation of a roughened surface. The electroless copper deposited on the modified POSS surface exhibited excellent adhesion when annealed at 180 • C in nitrogen for 90 min or at room temperature for 24 hr. Electroless copper deposition was also demonstrated on oxidized silicon wafers for through silicon via sidewall deposition.
Electroless copper deposition was investigated on epoxy laminate substrates (Isola 185HR) using a... more Electroless copper deposition was investigated on epoxy laminate substrates (Isola 185HR) using a silver-based catalyst, and a nonroughening surface treatment method based on sulfuric acid. The current challenges in electroless copper deposition include (i) high cost of Pd-based catalysts, (ii) deterioration of electrical performance of deposited metal at high frequency due to electron scattering at the roughened surface, and (iii) limited adhesion strength of electroless layers to substrates. We investigated an electroless copper deposition procedure composed of a H 2 SO 4 surface pretreatment, two-step Sn/Ag nano-colloidal catalyst seeding, and immersion in a traditional formaldehyde-containing electroless copper bath. The H 2 SO 4 pretreatment activated the epoxy surface for electroless deposition. Other strong acids did not lead to deposition. The H 2 SO 4 treatment cleaned the substrate and provided the adhesion of the catalyst and electroless copper without increasing the surface roughness. XPS results showed a decrease in the carbonyl groups (C=O), and acid/ester functionalities (O-C=O) at the surface. Adsorbed sulfate on the substrate from the H 2 SO 4 treatment led to Sn(II) sensitization. The tin-silver activation step resulted in Sn(IV) and Ag(0) products in the form of a Sn/Ag nano-colloidal catalyst. The Sn/Ag colloid acted as a catalyst for electroless copper deposition on the epoxy laminate substrates.
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Papers by Zachary Wilson