Biological electricity generation system based on mitochondria-nanochannel-red blood cells

The high-efficiency energy conversion process in organisms is usually carried out by organelles, proteins and membrane systems. Inspired by the cellular aerobic respiration process, we present an artificial electricity generation device, aimed at sustainable and efficient energy conversion using biological components, to demonstrate the feasibility of bio-inspired energy generation for renewable energy solutions. This approach bridges biological mechanisms and technology, offering a pathway to sustainable, biocompatible energy sources. The device features a mitochondria anode and oxygen-carrying red blood cells (RBCs) cathode, alongside a sandwich-structured sulfonated poly(ether ether ketone) and polyimide composite nanochannel for efficient proton transportation, mimicking cellular respiration. Achieving significant performance with 40 wt% RBCs, it produced a current density of 6.42 mA cm-2 and a maximum power density of 1.21 mW cm-2, maintaining over 50% reactivity after 8 days. This research underscores the potential of bio-inspired systems for advancing sustainable energy technologies.

On-demand engineerable visible spectrum by fine control of electrochemical reactions

Tunability of optical performance is one of the key technologies for adaptive optoelectronic applications, such as camouflage clothing, displays, and infrared shielding. High-precision spectral tunability is of great importance for some special applications with on-demand adaptability but remains challenging. Here we demonstrate a galvanostatic control strategy to achieve this goal, relying on the finding of the quantitative correlation between optical properties and electrochemical reactions within materials. An electrochromic electro-optical efficiency index is established to optically fingerprint and precisely identify electrochemical redox reactions in the electrochromic device. Consequently, the charge-transfer process during galvanostatic electrochemical reaction can be quantitatively regulated, permitting precise control over the final optical performance and on-demand adaptability of electrochromic devices as evidenced by an ultralow deviation of <3.0%. These findings not only provide opportunities for future adaptive optoelectronic applications with strict demand on precise spectral tunability but also will promote in situ quantitative research in a wide range of spectroelectrochemistry, electrochemical energy storage, electrocatalysis, and material chemistry.

Niobium Oxide Anode with Lattice Structure Self-Optimization for High-Power and Nearly Zero-Degeneration Battery Operation

Li+ insertion-induced structure transformation in crystalline electrodes vitally influence the energy density and cycle life of secondary lithium-ion battery. However, the influence mechanism of structure transformation-induced Li+ migration on the electrochemical performance of micro-crystal materials is still unclear and the strategy to profit from such structure transformation remains exploited. Here, an interesting self-optimization of structure evolution during electrochemical cycling in Nb2 O5 micro-crystal with rich domain boundaries is demonstrated, which greatly improves the charge transfer property and mechanical strength. The lattice rearrangement activates the Li+ diffusion kinetics and hinders the particle crack, thus enabling a nearly zero-degeneration operation after 8000 cycles. Full cell paired with lithium cobalt oxides displays an exceptionally high capacity of 176 mA h g-1 at 8000 mA g-1 and excellent long-term durability at 6000 mA g-1 with 63% capacity retention over 2000 cycles. Interestingly, a unique fingerprint based on the intensity ratio of two X-ray diffraction peaks is successfully extracted as a measure of Nb2 O5 electrochemical performance. The structure self-optimization for fast charge transfer and high mechanical strength exemplifies a new battery electrode design concept and opens up a vast space of strategy to develop high-performance lithium-ion batteries with high energy density and ultra-long cycle life.

Flexible Inorganic All-Solid-State Electrochromic Devices toward Visual Energy Storage and Two-Dimensional Color Tunability

Multicolor display has gradually become a sought-after trend for electrochromic devices due to its broadened application scope. Meanwhile, the advantages of inorganic electrochromic devices such as stable electrochemical performance and good energy storage ability also have great attraction in practical production applications. However, there are still huge challenges for inorganic electrochromic materials to achieve multicolor transformation due to their single-color hue change. Herein, we design an inorganic and multicolor electrochromic energy storage device (MEESD) exhibiting flexibility and all-solid-state merits. Prussian blue (PB) and MnO₂, as the asymmetrical electrodes of this MEESD, show good pseudocapacitance property, matching charge capacity, and obvious color change. As a typical electrochromic device, the MEESD shows a fast response of 0.5 s and good coloration efficiency of 144.2 cm²/C. As an energy storage device, the MEESD presents excellent rate capability and volumetric energy/power density (84.2 mWh cm^-3/23.3 W cm^-3). Its energy level can be visually monitored by color contrast and optical modulation. In the charging/discharging process, its color can obviously change to various degrees of yellow, green, and blue along with 40% wide optical modulation at 710 nm. Meanwhile, the stability of the MEESD in a common and humidity environment was analyzed in detail from electrochemical, optical, and energy storage aspects. This work provides feasible thoughts to design multifunctional electrochromic devices integrated with inorganic, flexible, all-solid-state, multicolor, and energy storage properties.

One-Step Synthesis of Three-Dimensional Na3V2(PO4)3/Carbon Frameworks as Promising Sodium-Ion Battery Cathode

Sodium-ion batteries (SIBs) are essential for large-scale energy storage attributed to the high abundance of sodium. Polyanion Na₃V₂(PO₄)₃ (NVP) is a dominant cathode candidate for SIBs because of its high-voltage and sodium superionic conductor (NASICON) framework. However, the electrochemical performance of NVP is hindered by the inherently poor electronic conductivity, especially for extreme fast charging and long-duration cycling. Herein, we develop a facile one-step in-situ polycondensation method to synthesize the three-dimensional (3D) Na₃V₂(PO₄)₃/holey-carbon frameworks (NVP@C) by using melamine as carbon source. In this architecture, NVP crystals intergrown with the 3D holey-carbon frameworks provide rapid transport pathways for ion/electron transmission to increase the ultrahigh rate ability and cycle capability. Consequently, the NVP@C cathode possesses a high reversible capacity of 113.9 mAh g^-1 at 100 mA g^-1 and delivers an outstanding high-rate capability of 75.3 mAh g^-1 at 6000 mA g^-1. Moreover, it shows that the NVP@C cathode is able to display a volumetric energy density of 54 Wh L^-1 at 6000 mA g^-1 (31 Wh L^-1 for NVP bulk), as well as excellent cycling performance of 65.4 mAh g^-1 after 1000 cycles at 2000 mA g^-1. Furthermore, the NVP@C exhibits remarkable reversible capabilities of 81.9 mAh g^-1 at a current density of 100 mA g^-1 and 60.2 mAh g^-1 at 1000 mA g^-1 even at a low temperature of -15 °C. The structure of porous carbon frameworks combined with single crystal materials by in-situ polycondensation offers general guidelines for the design of sodium, lithium and potassium energy storage materials.

Novel Prussian White@MnO2-Based Inorganic Electrochromic Energy Storage Devices with Integrated Flexibility, Multicolor, and Long Life

Flexible electrochromic devices have attracted considerable attention in recent years due to their great potential in smart multifunction electrochromic energy storage devices and wearable intelligent electronics. Herein, we present an inorganic flexible Li-based electrochromic energy storage device (EESD) by combining a Prussian white@MnO₂-composited electrode (PWM) and sputtering-made WO₃ electrode. The synergistic effect of Prussian white and MnO₂ plays a positive role both in energy storage and electrochromic property of the EESD. Its energy level can be quantified by the transmittance spectrum and chrominance difference, and its charging-discharging process can be monitored in real time by optical modulation at special wavelength. Specifically, the EESD can endure a 10,000 times cyclic voltammetry cycle without obvious degradation at wide voltage windows (-2 to 2.5 V) and realize a high coloration efficiency (77.6 cm²/C) with 35% optical modulation at 510 nm. In terms of energy storage performance, the EESD demonstrates excellent volumetric energy/power density (1.25 W cm^-3/13.2 mWh cm^-3) and remarkable stability with close to 98.3% capacitance retention and 99.4% coulombic efficiency after more than 4000 cycles. Its charging and discharging degree can be visualized in different spectral regions. There are 40% transmittance change for charging in the blue light region (450-480 nm) and 45% transmittance change for discharging in the red light region (620-750 nm). Based on its multicolor property, a quantitative indicator of charge state is achieved by the linear dependence of real-time chrominance change as stored or released charge. The ∼11 mC/cm² stored charge capacity can cause an ∼11 increase in chrominance difference ΔE value, while ∼7 mC/cm² discharge capacity can cause a ΔE value increase of ∼4. This work provides an efficient strategy to develop portable multicolor-integrated EESDs toward high performance and long stability.

Brain Wave-Like Signal Modulator by Ionic Nanochannel Rectifier Bridges

Smart modulation of bioelectric signals is of great significance for the development of brain-computer interfaces, bio-computers, and other technologies. The regulation and transmission of bioelectrical signals are realized through the synergistic action of various ion channels in organisms. The bionic nanochannels, which have similar physiological working environment and ion rectification as their biological counterparts, can be used to construct ion rectifier bridges to modulate the bioelectric signals. Here, the artificial smart ionic rectifier bridge with light response is constructed by anodic aluminum oxide (AAO)/poly (spiropyran acrylate) (PSP) nanochannels. The output ion current of the rectifier bridge can be switched between "ON" and "OFF" states by irradiation with UV and visible (Vis) light, and the conversion efficiency (η) of the system in "ON" state is ≈70.5%. The controllable modulation of brain wave-like signal can be realized by ionic rectifier bridge. The ion transport properties and processes of ion rectifier bridges are explained using theoretical calculations based on Poisson-Nernst-Planck (PNP) equations. These findings have significant implications for the understanding of the intelligent ionic circuit and combination of artificial smart ionic channels to organisms, which provide new avenues for development of intelligent ion devices.

Effective catalytic steam reforming of naphthalene over Ni-modified ZSM-5 via one-pot hydrothermal synthesis

Ni-modified ZSM-5 catalysts are prepared by a one-pot hydrothermal synthesis method and applied to the steam reforming of naphthalene as a tar model compound. The effects of the reaction temperature, silica-alumina ratio (Si/Al) and metal content on the catalytic performance for reforming naphthalene are investigated. Characterization results indicate that the Ni-modified ZSM-5 catalysts maintain the original MFI structure of ZSM-5 and a portion of Ni is successfully introduced into the zeolite structure. When the reaction temperature is 800 °C, the conversion efficiency of naphthalene achieves 91.5% with a high yield (6.75%) of hydrogen. Zeolite catalysts with higher Si/Al ratios improve the conversion of naphthalene to syngas, demonstrating their better catalytic activity. An appropriate active metal content (2.4 wt%) contributes to the catalytic performance of the catalyst owing to the strong metal-support interaction, resulting in resistance to sintering and carbon deposition. The reaction mechanism involved in the catalytic reforming of naphthalene is proposed. The application of a novel one-pot hydrothermal synthesis method greatly promoted the catalytic activity of Ni@ZSM-5, which provided an appropriate and universal approach for the improvement and optimization of tar reforming catalysts.

Self-Driven Electrochromic Window System Cu/WOx-Al3+/GR with Dynamic Optical Modulation and Static Graph Display Functions

Electrochromic devices with unique advantages of electrical/optical bistability are highly desired for energy-saving and information storage applications. Here, we put forward a self-driven Al-ion electrochromic system, which utilizes WO_x films, Cu foil, and graphite rod as electrochromic optical modulation and graph display electrodes, coloration potential supplying electrodes, and bleaching potential supplying electrodes, respectively. The inactive Cu electrode can not only realize the effective Al³⁺ cation intercalation into electrochromic WO_x electrodes but also eliminate the problem of metal anode consumption. The electrochromic WO_x electrodes cycled in Al³⁺ aqueous media exhibit a wide potential window (∼1.5 V), high coloration efficiency (36.0 cm²/C), and super-long-term cycle stability (>2000 cycles). The dynamic optical modulation and static graph display function can be achieved independently only by switching the electrode connection mode, thus bringing more features to this electrochromic system. For a large-area electrochromic system (10 × 10 cm²), the absolute transmittance value in its color-neutral state can reach about 41% (27%) at 633 nm (780 nm) by connecting the Cu and WO_x electrodes for 140 s. The original transparent state can be readily recovered by replacing the Cu foil with the graphite rod. This work throws light on next-generation electrochromic applications for optical/thermal modulation, privacy protection, and information display.

Energy storage electrochromic devices in the era of intelligent automation

The current intelligent automation society faces increasingly severe challenges in achieving efficient storage and utilization of energy. In the field of energy applications, various energy technologies need to be more intelligent and efficient to produce, store, transform and save energy. In addition, many smart electronic devices facing the future also require newer, lighter, thinner and even transparent multi-functional power supplies. The unique properties of electrochromic energy storage devices (ECESDs) have attracted widespread attention. In the field of energy applications, they have high potential value and competitiveness. This review focuses on the electrochromic basic principles, and the latest technological examples of ECESDs, which are related to materials and device structures. Simultaneously, this review makes a detailed comparison and summary of example performances. Moreover, the review compares the current mainstream energy storage devices: lithium batteries and supercapacitors, and the main challenges of ECESDs are discussed. Finally, the future development directions in the field of electrochromic energy storage are predicted.

Kinetic Process of an Alkaline Earth Metal Ion Transmembrane through ZIF-8

The confinement effect of biological ion channels regulates the transport of molecules and ions due to angstrom-sized pores. The structure of the potassium channel has a selection region (3-4 Å), a cavity (10 Å), and a gated region, while ZIF-8 has intrinsic pores with a 3.4 Å aperture and an 11.6 Å cavity similar to those of the potassium channel. Inspired by this, we constructed the glass/ZIF-8 hybrid membrane through an electrochemical growth process to explore the kinetics of the ion transmembrane by I-V curves and electrochemical impedance spectroscopy. These complementary approaches yield highly correlated results that show that ion transportation of the ZIF-8 membrane follows Arrhenius behavior. The rates of ions are controlled by the transmembrane activation energy, in which the ionic charge and radius play an important role.

Unprecedented Electrochromic Stability of a-WO3-x Thin Films Achieved by Using a Hybrid-Cationic Electrolyte

With large interstitial space volumes and fast ion diffusion pathways, amorphous metal oxides as cathodic intercalation materials for electrochromic devices have attracted attention. However, these incompact thin films normally suffer from two inevitable imperfections: self-deintercalation of guest ions and poor stability of the structure, which constitute a big obstacle toward the development of high-stable commercial applications. Here, we present a low-cost, eco-friendly hybrid cation 1,2-PG-AlCl₃·6H₂O electrolyte, in which the sputter-deposited a-WO_3-x thin film can exhibit both the long-desired excellent open-circuit memory (>100 h, with zero optical loss) and super-long cycling lifetime (∼20,000 cycles, with 80% optical modulation), benefiting from the formation of unique Al-hydroxide-based solid electrolyte interphase during electrochromic operations. In addition, the optical absorption behaviors in a-WO_3-x caused by host-guest interactions were elaborated. We demonstrated that the intervalence transfers are primarily via the "corner-sharing" related path (W⁵⁺ ↔ W⁶⁺) but not the "edge-sharing" related paths (W⁴⁺ ↔ W⁶⁺ and/or W⁴⁺ ↔ W⁵⁺), and the small polaron/electron transfers taking place at the W-O bond-breaking positions are not allowed. Our findings might provide in-depth insights into the nature of electrochromism and provide a significant step in the realization of more stable, more excellent electrochromic applications based on amorphous metal oxides.

Removal of tar derived from biomass gasification via synergy of non-thermal plasma and catalysis

In this study, the reforming of toluene, as a surrogate for tar, was investigated in plasma-alone (PA) and plasma-catalytic (PC) systems. The effects of feed gas oxygen content (O₂/(O₂ + N₂) = 0, 3, 12, 21, or 30 vol%) and the discharge power (30, 75, or 90 W) on toluene conversion, the selectivity of syngas (H₂ + CO), and undesirable liquid by-products were evaluated using the PA system. A maximum toluene conversion of 87.9% and a minimum selectivity of undesirable liquid by-products of 0.53% for ethylbenzene, and 1.24% for benzene, were obtained when the discharge power was 90 W and the oxygen content in the carrier gas was 3 vol%. However, a maximum gas selectivity of 48.4% for H₂ and 19.4% for CO was attained when the discharge power was 75 W and the oxygen content was 3 vol% and 12 vol%, respectively. The effect of the steam/carbon molar ratio (S/C) on toluene reforming was investigated using the PC system with Ni/ZSM-5 catalyst under a discharge power of 75 W. The addition of steam to the feed gas significantly enhanced the conversion of toluene to syngas. A maximum toluene conversion of 88.5% was reached with a minimum selectivity of liquid by-products (1.9% for ethylbenzene and 5.2% for benzene) when S/C was 2. However, the highest selectivity of syngas (69.8% for H₂ and 21.2% for CO) was achieved when S/C was 2.5. The catalyst employed in the plasma reforming of toluene exhibited excellent anti-carbon deposition performance. A possible reaction mechanism and pathway of toluene destruction was proposed based on analysis of both gaseous and liquid products.

A tunable floating-base bipolar transistor based on a 2D material homojunction realized using a solid ionic dielectric material

Floating-base bipolar transistors are widely used semiconductor devices because they could both amplify signal current and suppress noise. Employing two-dimensional (2D) materials of ultrahigh photoelectric properties could further improve the device performance. Due to the difficulty in doping, homojunctions are usually not realizable for many 2D materials. Instead, a heterojunction of various 2D materials of different Fermi levels is usually needed. However, the material interface of a heterojunction deteriorates device performance and makes the fabrication process difficult. Here, the doping difficulties have been solved by utilizing a solid ionic dielectric material (LiTaO3) and a floating-base bipolar transistor based on a 2D material (monolayer MoS2 here) homojunction is realized. The transistor shows tunable ambipolar transport characteristics. Particularly, under illumination, the amplification coefficient of a phototransistor can be optimized by changing the gate voltage. The optimized photoresponsivity of the device could reach up to 7.9 A W-1 with an ultrahigh detectivity of 3.39 × 1011 Jones. The overall fabrication processing is compatible to conventional processing. This design can effectively extend the application of 2D materials.

Insight into the low-temperature decomposition of Aroclor 1254 over activated carbon-supported bimetallic catalysts obtained with XANES and DFT calculations

Novel bimetallic catalysts supported on activated carbon (AC) with high metal loadings were synthesized by carbonizing an ion-exchange resin. AC-supported Ni-Cu (Ni-Cu/C) and Ni-Zn (Ni-Zn/C) bimetallic catalysts with different Ni:Cu(Zn) ratios were used to decompose Aroclor 1254, which is a commonly used commercial mixture of polychlorinated biphenyls. Characterization with scanning electron microscopy and energydispersive X-ray spectroscopy showed that the metals were uniformly distributed on the surfaces and inside the catalysts. After 30 min reaction over the Ni-Cu/C catalyst at a low temperature of 250 °C, the efficiencies of Hexa-CBs decomposition present in Aroclor 1254 exceeded 97%, which were higher than those achieved over Ni-Zn/C. These efficiencies increased with Cu content in Ni-Cu/C, and decreased with the amount of Zn in Ni-Zn/C. X-ray photoelectron spectra and X-ray absorption near-edge structure spectra of Ni-Cu/C and Ni-Zn/C before and after the reaction indicated that Ni and Cu were oxidized during the reaction. However, Zn showed no significant change, suggesting that Ni and Cu are the active components to promote reaction with Aroclor 1254, whereas Zn is only a spectator. The efficiencies of Aroclor 1254 decomposition over bimetallic catalysts were greater than those over monometallic catalysts, which was confirmed by density functional theory calculations.

Life-cycling and uncovering cation-trapping evidence of a monolithic inorganic electrochromic device: glass/ITO/WO3/LiTaO3/NiO/ITO

The visualization of the microstructure change and of the depth of lithium transport inside a monolithic ElectroChromic Device (ECD) is realized using an innovative combined approach of Focused Ion Beam (FIB), Secondary Ion Mass Spectrometry (SIMS) and Glow Discharge Optical Emission Spectroscopy (GDOES). The electrochemical and optical properties of the all-thin-film inorganic ECD glass/ITO/WO3/LiTaO3/NiO/ITO, deposited by magnetron sputtering, are measured by cycling voltammetry and in situ transmittance analysis up to 11 270 cycles. A significant degradation corresponding to a decrease in the capacity of 71% after 2500 cycles and of 94% after 11 270 cycles is reported. The depth resolved microstructure evolution within the device, investigated by cross-sectional cutting with FIB, points out a progressive densification of the NiO layer upon cycling. The existence of irreversible Li ion trapping in NiO is illustrated through the comparison of the compositional distribution of the device after various cycles 0, 100, 1000, 5000 and 11 270. SIMS and GDOES depth profiles confirm an increase in the trapped Li content in NiO as the number of cycles increases. Therefore, the combination of lithium trapping and apparent morphological densification evolution in NiO is believed to account for the degradation of the ECD properties upon long term cycling of the ECD.

Robust Sandwich-Structured Nanofluidic Diodes Modulating Ionic Transport for an Enhanced Electrochromic Performance

Biomimetic solid-state nanofluidic diodes have attracted extensive research interest due to the possible applications in various fields, such as biosensing, energy conversion, and nanofluidic circuits. However, contributions of exterior surface to the transmembrane ionic transport are often ignored, which can be a crucial factor for ion rectification behavior. Herein, a rational design of robust sandwich-structured nanofluidic diode is shown by creating opposite charges on the exterior surfaces of a nanoporous membrane using inorganic oxides with distinct isoelectric points. Potential-induced changes in ion concentration within the nanopores lead to a current rectification; the results are subsequently supported by a theoretical simulation. Except for providing surface charges, functional inorganic oxides used in this work are complementary electrochromic materials. Hence, the sandwich-structured nanofluidic diode is further developed into an electrochromic membrane exhibiting a visual color change in response to redox potentials. The results show that the surface-charge-governed ionic transport and the nanoporous structure facilitate the migration of Li+ ions, which in turn enhance the electrochromic performance. It is envisioned that this work will create new avenues to design and optimize nanofluidic diodes and electrochromic devices.

Highly Efficient Gating of Electrically Actuated Nanochannels for Pulsatile Drug Delivery Stemming from a Reversible Wettability Switch

Many ion channels in the cell membrane are believed to function as gates that control the water and ion flow through the transitions between an inherent hydrophobic state and a stimuli-induced hydration state. The construction of nanofluidic gating systems with high gating efficiency and reversibility is inspired by this hydrophobic gating behavior. A kind of electrically actuated nanochannel is developed by integrating a polypyrrole (PPy) micro/nanoporous film doped with perfluorooctanesulfonate ions onto an anodic aluminum oxide nanoporous membrane. Stemming from the reversible wettability switch of the doped PPy film in response to the applied redox potentials, the nanochannels exhibit highly efficient and reversible gating behaviors. The optimized gating ratio is over 10⁵ , which is an ultrahigh value when compared with that of the existing reversibly gated nanochannels with comparable pore diameters. Furthermore, the gating behavior of the electrically actuated nanochannels shows excellent repeatability and stability. Based on this highly efficient and reversible gating function, the electrically actuated nanochannels are further applied for drug delivery, which achieves the pulsatile release of two water-soluble drug models. The electrically actuated nanochannels may find potential applications in accurate and on-demand drug therapy.

Improved performance of co-sputtered Ni–Ti oxide films for all-solid-state electrochromic devices

Thin films of Ni–Ti oxide were co-sputtered by reactive direct current magnetron sputtering and their structures, morphologies, and compositions were investigated by X-ray diffraction, atomic force microscopy and X-ray photo-electron spectroscopy.

Myeloid Sarcoma Presenting With Multiple Skin and Subcutaneous Mass Without Leukemic Manifestations After Renal Transplantation

BACKGROUND

Myeloid sarcoma is well described and known in clinical practice, however, it is a rare condition after receiving renal transplantation. Immunosuppressive therapy is thought to be the main cause in these cases.

CASE REPORT

A 45-year-old woman accepted a right kidney transplantation because of her chronic renal insufficiency and uremia in May 2011. She had to receive a left kidney transplantation again in February 2012 because she had renal failure again after receiving the right kidney transplantation. She received immune inhibitors treatment. After the latter operation, her renal function was normal. The third operation was done to remove the right transplanted kidney in July 2012. The diagnosis of the kidney was myeloid sarcoma. The blood and bone marrow biopsy had no evidence of leukemia. She then received chemotherapy. There was a small skin nodule on the left arm of approximately 0.5 cm in August 2012; after that its diameter enlarged progressively to about 5 cm and more nodules and masses gradually appeared on her face, arms, trunk, lower limbs, and feet over the course of 1 year. The skin biopsy specimen obtained from her left arm showed myeloid sarcoma too. She was admitted to the Orthopedics Department for severe pain and swelling in the left foot in September 2014 and underwent an operation for resecting the mass in the left foot. Pain was apparently alleviated and the incision healed well.

CONCLUSIONS

The patient is still alive with no evidence of leukemia after a 30-month follow-up.

Monitoring oxidation of chlorinated ethenes by permanganate in groundwater using stable isotopes: laboratory and field studies

Permanganate injection is increasingly applied for in situ destruction of chlorinated ethenes in groundwater. This laboratory and field study demonstrates the roles that carbon isotope analysis can play in the assessment of oxidation of trichloroethene (TCE) by permanganate. In laboratory experiments a strong carbon isotope fractionation was observed during oxidation of TCE with similar isotopic enrichment factors (-25.1 to -26.8 per thousand) for initial KMnO4 concentrations between 67 and 1,250 mg/L. At the field site, a single permanganate injection episode was conducted in a sandy aquifer contaminated with TCE as dense nonaqueous liquid (DNAPL). After injection, enriched delta13C values of up to +204% and elevated Cl- concentrations were observed at distances of up to 4 m from the injection point. Farther away, the Cl- increased without any change in delta13C of TCE suggesting that Cl- was not produced locally but migrated to the sampling point Except for the closest sampling location to the injection point, the delta13C rebounded to the initial 613C again, likely due to dissolution of DNAPL Isotope mass balance calculations made it possible to identify zones where TCE oxidation continued to occur during the rebound phase. The study indicates that delta13C values can be used to assess the dynamics between TCE oxidation and dissolution and to locate zones of oxidation of chlorinated ethenes that cannot be identified from the Cl- distribution alone.

Evaluation of poly(styrene-4-sulfonate) as a preventive agent for conception and sexually transmitted diseases

A commercial preparation of a sodium polystyrene sulfonate (designated as N-PSS; its molecular weight is 500000 daltons) was tested as an inhibitor of sperm function and as a preventive agent for conception and the transmission of sexually transmitted diseases. The polymer is an irreversible inhibitor of hyaluronidase and acrosin; its IC50 values are 5.7 microg/mL and 0.5 microg/mL, for hyaluronidase and acrosin, respectively. N-PSS is also a stimulus of human sperm acrosomal loss. It produces maximal acrosomal loss at 2.5 microg/mL. Contraception in rabbits is nearly complete when rabbit spermatozoa are pretreated with 0.5 mg/mL of N-PSS before artificial insemination; however, N-PSS does not immobilize spermatozoa at concentrations as high as 50 mg/mL. N-PSS has broad spectrum antiviral and antibacterial activities. Infection by human immunodeficiency virus and herpes simplex virus are inhibited by N-PSS; 3-log reductions are produced by 7 microg/mL and 3 microg/mL, respectively. N-PSS is active against Chlamydia trachomatis and Neisseria gonorrhoeae. At 1 mg/mL, N-PSS inhibits chlamydial infectivity by more than 90%. N-PSS produces a 3-log reduction in gonococcal growth at 15 microg/mL. In contrast, N-PSS (5 mg/mL) does not affect the growth of Lactobacillus (normal component of the vaginal flora). N-PSS can be classified as a noncytotoxic contraceptive antimicrobial agent. These properties justify bringing a polystyrene sulfonate into clinical trials for its evaluation as a preventive agent for conception and several sexually transmitted diseases.

Determination of carcinogenic potency of alkytoxynol-741 (AP-741) by rat peritoneal cell cultures

The carcinogenic potency of AP-741 was tested in rats using the Nashed method of rat peritoneal cell short-term carcinogenic test. N-methyl-N-nitro-N'-nitrosoguanidian (MNNG) was used as positive control; saline and nonoxynol-9 (NP-9) were used as negative control. Two doses of AP-741 (4 mg/kg and 40 mg/kg equivalent to 4 and 40 times human doses) were tested. The result showed that no colonies of more than 9 cells were seen in the saline and NP-9 groups, and the two dose groups of AP-741. However, 12 +/- 8.3 colonies (9-29 cell/colony) and 4.5 +/- 4.2 colonies (30-300 cell/colony) were seen in the MNNG group. According to the Nashed criterion, we can say MNNG has potential carcinogenesis, while AP-741 does not have any potential carcinogenesis and its use as a vaginal contraceptive drug is safe.