Nonthermal Destruction Research Articles

Laser-Assisted Design of MOF-Derivative Platforms from Nano- to Centimeter Scales for Photonic and Catalytic Applications.

Laser conversion of metal-organic frameworks (MOFs) has recently emerged as a fast and low-energy consumptive approach to create scalable MOF derivatives for catalysis, energy, and optics. However, due to the virtually unlimited MOF structures and tunable laser parameters, the results of their interaction are unpredictable and poorly controlled. Here, we experimentally base a general approach to create nano- to centimeter-scale MOF derivatives with the desired nonlinear optical and catalytic properties. Five three- and two-dimensional MOFs, differing in chemical composition, topology, and thermal resistance, have been selected as precursors. Tuning the laser parameters (i.e., pulse duration from fs to ns and repetition rate from kHz to MHz), we switch between ultrafast nonthermal destruction and thermal decomposition of MOFs. We have established that regardless of the chemical composition and MOF topology, the tuning of the laser parameters allows obtaining a series of structurally different derivatives, and the transition from femtosecond to nanosecond laser regimes ensures the scaling of the derivatives from nano- to centimeter scales. Herein, the thermal resistance of MOFs affects the structure and chemical composition of the resulting derivatives. Finally, we outline the "laser parameters versus MOF structure" space, in which one can create the desired and scalable platforms with nonlinear optical properties from photoluminescence to light control and enhanced catalytic activity.

Solvent-Free Nonthermal Destruction of PFAS Chemicals and PFAS in Sediment by Piezoelectric Ball Milling.

Studies on the destruction of solid per- and polyfluoroalkyl substances (PFAS) chemicals and PFAS-laden solid wastes significantly lag behind the urgent social demand. There is a great need to develop novel treatment processes that can destroy nonaqueous PFAS at ambient temperatures and pressures. In this study, we develop a piezoelectric-material-assisted ball milling (PZM-BM) process built on the principle that ball collisions during milling can activate PZMs to generate ∼kV potentials for PFAS destruction in the absence of solvents. Using boron nitride (BN), a typical PZM, as an example, we successfully demonstrate the complete destruction and near-quantitative (∼100%) defluorination of solid PFOS and perfluorooctanoic acid (PFOA) after a 2 h treatment. This process was also used to treat PFAS-contaminated sediment. Approximately 80% of 21 targeted PFAS were destroyed after 6 h of treatment. The reaction mechanisms were determined to be a combination of piezo-electrochemical oxidation of PFAS and fluorination of BN. The PZM-BM process demonstrates many potential advantages, as the degradation of diverse PFAS is independent of functional group and chain configurations and does not require caustic chemicals, heating, or pressurization. This pioneering study lays the groundwork for optimizing PZM-BM to treat various PFAS-laden solid wastes.

Combination Irreversible Electroporation And Immunotherapy For Local And Abscopal Control Of Multifocal Hepatic Tumors

Presenter: Conor O'Neill MD | University of Louisville School of Medicine Background: Among patients with advanced hepatocellular carcinoma (HCC), outcomes remain poor. Sorafenib, an oral kinase inhibitor, remains the standard therapy but provides only marginal survival gains with a 10.7-month median overall survival. Recently, data have shown that combination ipilimumab, a CTLA-4 inhibitor, and nivolumab, a programmed cell death protein-1 inhibitor, provide objective response rates observed in 31% of patients and a disease control rate approaching 50%. Non-thermal tumor disruptive therapies are also of interest for advanced HCC for their ability to induce cell death without coagulative necrosis. This provides a theoretical advantage by increasing tumor antigen release for immune recognition and response. Irreversible electroporation (IRE) can be utilized around critical structures for non-thermal destruction of tumors. IRE has also been postulated to have an abscopal effect on lesions not in the tumor-ablative field, possibly through heightened immunologic response. We evaluated whether combination nivolumab (+) ipilimumab and IRE would lead to increased tumor necrosis and T cell recruitment to both the treated tumors and tumors outside the local ablative field. Methods: C57L/J mice (Jackson Laboratory, ME) underwent laparotomy and tumor implantation of 1mmˆ3 sections of Hepa1-6 tumors into the right and left lobes of the liver. Tumors were allowed to mature for 2 weeks. Five groups of mice (n=30) were measured: Group 1 mice were controls with no tumor, Group 2 mice had tumor implantation alone, Group 3 received IRE with 2500 Volts at a pulse length of 100us, pulse interval 100ms and 10 pulses to the left lobe tumor, Group 4 received weekly intraperitoneal injections of ipilimumab (3mg/kg) and nivolumab (10 mg/kg) for 4 weeks and Group 5 received IRE and combination immunotherapy for four weeks. After treatment, the liver was harvested for analysis. Co-culture cell-migration studies were performed. Briefly, hepa1-6 cell cultures either alone or following IRE-treatment were plated into 24-well plates in serum-free medium or medium containing ipilimumab and nivolumab. Co-culture insets were placed in each well containing 1X10ˆ5 mouse lymphoma T cells. Cell migration was analyzed by cell counting at six hours. Results: Mouse tumors treated with IRE (Groups 3&5) had extensive necrosis visible on H&E staining (figure 1). Group 4 mice treated with immunotherapy alone demonstrated minimal tumor necrosis or peritumoral infiltrate. There were significant increases in both tumor necrosis and CD-8(+) T-cell infiltrate for tumors outside the electroporated field for mice treated with both immunotherapy and IRE (p<0.05); tumors treated with IRE directly and immunotherapy had significantly greater necrosis and peritumoral CD-8(+) T cell infiltrate than tumors outside the treated field or for tumors in Groups 1-4 (p<0.05). Similarly, cell migration studies confirmed significantly higher T cell recruitment in cultures containing electroporated Hepa1-6 cells and combination immunotherapies. Conclusion: Murine models of hepatocellular carcinoma demonstrate significant increases in peritumoral T cell recruitment and tumoral necrosis of both primary and abscopal tumors when IRE and combination immunotherapy are utilized. Further research is required to develop mechanistic insight prior to clinical trial initiation.

Degradation and Removal Methods for Perfluoroalkyl and Polyfluoroalkyl Substances in Water

Abstract Several perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been identified as chemicals of concern in the environment due to their persistence, global ubiquity, and classification as reproductive and developmental toxicants, endocrine disrupters, and possible carcinogens. Multiple PFASs are often found together in the environment due to product manufacturing methods and abiotic and biotic transformations. Treatment methods are needed to effectively sequester or destroy a variety of PFASs from groundwater, drinking water, and wastewater. This review presents a comprehensive summary of several categories of treatment approaches: (1) sorption using activated carbon, ion exchange, or other sorbents, (2) advanced oxidation processes, including electrochemical oxidation, photolysis, and photocatalysis, (3) advanced reduction processes using aqueous iodide or dithionite and sulfite, (4) thermal and nonthermal destruction, including incineration, sonochemical degradation, sub- or supercritical tr...

Non-Thermal Destruction of Prostate Cancer by Irreversible Electroporation

Non-Thermal Destruction of Prostate Cancer by Irreversible Electroporation

Mechanisms of nonthermal destruction of the superconducting state and melting of the charge-density-wave state by femtosecond laser pulses

The processes leading to nonthermal condensate vaporization and charge-density wave (CDW) melting with femtosecond laser pulses is systematically investigated in different materials. We find that vaporization is relatively slow (tau_v ~ 1 ps) and inefficient in superconductors, exhibiting a strong systematic dependence of the vaporization energy Uv on Tc. In contrast, melting of CDW order proceeds rapidly (tau_m = 50 ~ 200 fs) and more efficiently. A quantitative model describing the observed systematic behavior in superconductors is proposed based on a phonon-mediated quasi-particle (QP) bottleneck mechanism. In contrast, Fermi surface disruption by hot QPs is proposed to be responsible for CDW state melting.

Nanoscale modification of dielectrics under ultrashort laser pulses action on the nanoparticle-at-the-substrate system

The results of theoretical analysis of the response of solid nanoparticles on the dielectric surface to the intense ultrashort laser pulse (USLP) action are presented. The estimation of the ionization degree of nanoparticles with permanently changing charge on the composition, intensity and laser pulse duration has been carried out using a simple analytical model. The dynamics of non-thermal destruction of nanoparticles and associated changes in the substrate surface due to the implantation of ions emitted from nanoparticles has been studied using numerical simulation.

On saturation of betatron acceleration of dust particles behind shock fronts

Possible saturation of betatron acceleration of dust particles behind strong shock fronts from supernovae is considered. It is argued that the efficiency of the nonthermal dust destruction should be substantially lower than the value estimated from a traditional description of betatron acceleration of dust grains behind radiative shock waves. The inhibition of the nonthermal destruction can be connected with the mirror instability developed in the dust component behind strong shocks with the velocity 3 times exceeding the Alfv\'en speed. The instability develops on characteristic time scales much shorter the age of a supernova remnant, thus its influence on the efficiency of dust destruction can be substantial: in the range of shock velocities 100 km s$^{-1}<v_s<300$ km s$^{-1}$ the destruction efficiency can be an order of magnitude lower that normally estimated.

Comparison of quality attributes of shell eggs subjected to directional microwave technology

Microwaves have been shown to cause thermal as well as nonthermal destruction of pathogens such as Salmonella, which can be found in shell eggs. The objective of this study was to determine if using microwave technology would cause detrimental quality effects in shell eggs. Treatments included control (no treatment) and microwave-treated (20 s) shell eggs. There were no differences in mineral content, fatty acid profile, Haugh units, broken-out score, yolk index, emulsion stability, pH of whole egg, and foaming capacity between 2 treatments (P >or= 0.05). At 0 and 30 d, there were no noticeable differences in H(2)O activity between 2 treatments. The foaming stability and albumen thermocoagulation of microwave-treated eggs were significantly higher than control eggs (P <or= 0.05). The control eggs had significantly higher emulsion capacity and lower vitelline membrane strength than the microwave-treated eggs (P <or= 0.05). Poached eggs were evaluated by sensory testing for hardness, yolk color, and albumen color, and there are no noticeable differences at 0, 15, or 30 d. At 0 d, the color of control albumen was more yellow than the microwave-treated albumen, and the chalazae of the microwave-treated eggs was more attached than the control eggs (P <or= 0.05). The TBA reactive substances were similar for 2 treatments at 0, 15, and 30 d. Peroxide values were significantly higher in the microwave-treated eggs at d 0 (P <or= 0.05), but at 15 and 30 d, no prominent differences in peroxide values were noted (P >or= 0.05). Therefore, microwave technology can be applied to shell eggs without causing detrimental effects to quality.

Reduction of Salmonella Enteritidis in Shell Eggs Using Directional Microwave Technology

Microwaves have been shown to cause thermal as well as nonthermal destruction of pathogens such as Salmonella Enteritidis, which is commonly found in shell eggs. The objective of this study was to examine the use of new directional microwave technology to reduce Salmonella Enteritidis without causing any detrimental effects on quality in white and brown eggs. Treatments were control and microwaved white and brown eggs. Applying directional microwave technology resulted in a 2-log reduction of Salmonella Enteritidis in both the high (10(5) cfu/g) and low (10(2) cfu/g) inoculum. At d 0, there were no differences in water activities, albumen pH, and combined pH between treatments; however, there were significant changes in yolk pH. Collectively, these results indicate that applying directional microwave technology can reduce Salmonella Enteritidis in shell eggs without causing any detrimental effects to quality.

Pulsed Cavitational Ultrasound: A Noninvasive Technology for Controlled Tissue Ablation (Histotripsy) in the Rabbit Kidney

The optimal minimally invasive treatment for small renal masses continues to evolve. Current ablative technologies rely on thermal mechanisms for tissue destruction. However, the creation of precise lesions is limited by inhomogeneous heating/cooling due to tissue variability, perfusion effects and tissue charring. We hypothesized that nonthermal mechanical effects of ultrasound (cavitation) can be used to progressively homogenize tissue in controlled fashion with predictable results. We developed a focused annular array ultrasound system capable of delivering high intensity (greater than 20 kW/cm) short pulses (20 microseconds) of energy to a target volume. This system operates at a repetition frequency of 100 Hz, resulting in a low time averaged power output (approximately 5 W total acoustic output). Following approval from the institutional animal care committee a series of transcutaneous ablations were performed in the normal kidneys of 10 rabbits. Lesions created with a small number of pulses (10 or 100) produced scattered areas of damage characterized by focal hemorrhage and small areas of cellular injury in the targeted volume. Lesions created with greater numbers of pulses (1,000 or 10,000) demonstrated complete destruction of the targeted volume. Gross examination revealed that lesions contained a liquefied core with smooth walls and sharply demarcated boundaries. Histological examination demonstrated extensive areas of acellular debris surrounded by a narrow margin of cellular injury. This pulsed cavitational ultrasound system is capable of transcutaneous nonthermal destruction of renal tissue. Refinement of this technology for noninvasive ablation of small renal masses is currently under way.

Dioxin mass balance in a municipal waste incinerator

A dioxin mass balance in an Spanish municipal waste incinerator (MWI) is presented. Input and output inventories from two sampling collection episodes including the analysis of PCDD/PCDF in urban solid waste (USW), stack gas emissions, fly ash and slag are reported. In one collection the levels of USW were around 8 pg I-TEQ/g and non-thermal destruction was observed overall. In the other collection the levels of USW were higher (around 64 pg I-TEQ/g) and the dioxin balance revealed a thermal destruction. Analysis of the different waste materials (textile, organic, plastic, wood and paper) was performed separately and the textile samples presented the highest levels.

Application of the SOLVTM Process: A Total Systems Approach to Environmental Remediation

AbstractCommodore Solution Technologies, Inc. has developed an innovative total systems approach to environmental remediation that utilizes a patented chemistry called Solvated Electron Technology (SETTM). Solvated electron solutions are some of the most powerful reducing agents know. Formed by dissolving alkali and alkaline‐earth metals in anhydrous liquid ammonia to produce a solution of metal cations and free electrons, solvated electron solutions are capable of providing reductants of great activity and uniqueness. They provide a highly useful mechanism for the reductive destruction of many organic molecules and are extremely effective in the dehalogenation of halogenated organic compounds. Commodore has received a nation‐wide EPA operating permit for the nonthermal destruction of PCBs using this process. The SoLVTM process is a total solution approach that incorporates SETTM with pre‐and post‐treatments, when necessary, for environmental cleanup. It is applicable to a broad range of substrates including liquids, solids, soils, and job materials. This article presents results from several pilot, field, and commercial validation studies utilizing the SoLVTM process.

Kinetic Analogies Between Decomposition of 1,2-Dichloroethane and Chloroform Under Non-Thermal Reducing RF Plasma Conditions

The decomposition of 1,2-dichloroethane (1,2-C2H4Cl2) has been studied under non-equilibrium plasma conditions in a low pressure (20 mbar) capacitively coupled rf hydrogen plasma (CCP) operating at low power levels of 1-10 W/cm3 and residence times of 0.03-0.1 s. The qualitative and quantitative distribution of the products analyzed by a GC/MS system has been compared with the product spectrum of the chloroform (CHCl3) conversion under the same plasma conditions. The observed similarities between the two product spectra are interpreted by kinetic analogies of the non-thermal destruction processes of these two chlorinated hydrocarbons. A corresponding qualitative reaction mechanism basing on elementary radical reactions is discussed.

Effect of Microwaves on Microorganisms in Foods

Microwave cooking has increased in popularity in recent years. Since the time to process food is much shorter than with conventional methods, questions have been raised as to the microbial safety of foods cooked with microwaves. The first part of this review includes discussions on the importance of intrinsic and extrinsic characteristics of foods in relation to destruction of microorganisms in microwave-cooked foods, the mechanism of microwave destruction of microorganisms and viewpoints on the thermal and nonthermal destruction of microorganisms. The second part includes data on the effect of time and temperature on microorganisms in microwave-cooked foods, the effect of microwave destruction of microorganisms in different food systems and the effect of microwaves on different bacteria. The last section includes discussions of destruction of microorganisms by microwave cooking of meats, poultry and egg products, dairy products, cereal products, fruit products, vegetables and miscellaneous foods. We observed that (a) microwave heating of food is more “food dependent” than conventional heating, (b) the manufacturer-recommended microwave treatment time for some foods may not destroy high levels of bacteria, (c) use of microwaves in combination with other conventional heating methods results in more uniform heating in foods and destruction of bacteria, (d) heat generated by microwaves kills naturally-occurring microorganisms as long as the size and type of food are carefully correlated with exposure time, (e) microwaves exert different killing effects on individual bacterial species and (f) the question of thermal versus nonthermal effects of microwaves on microorganisms has not been settled. We believe microwave heating is an important method for processing of foods at home, in institutions and in commercial operations. The process is acceptable from the standpoint of food spoilage and food safety as long as the users understand the limitations and possibilities of microwave heating and are aware of some of the major points presented in this review.