Permanent Modification Research Articles

Conservation of endangered species through somatic cell nuclear transfer (SCNT)

Currently, the conservation of biodiversity is a pressing issue due to the extinction and endangerment of many species. There are multiple reasons for the extinction or endangerment of species including anthropogenic (poaching, hunting, and deforestation) and natural causes (forest fire, invasion of non-local species, climate change, and global warming). The somatic cell nuclear transfer (SCNT) is an emerging tactic, which requires the nucleus from a donor somatic cell, which is transferred to the enucleated oocyte in vitro, for the conservation of biodiversity, especially related to the wildlife which is gradually decreasing with the fear of extinction. Somatic cell nuclear transfer has a broad spectrum of potential applications, including the rescue of endangered species, the resurrection of extinct species, the production of transgenic animals, drug production, and regenerative medicine. Reproductive cloning of animals by SCNT can also offer permanent gene editing, genetic modification, and gene derives for the production of species adaptive to their native habitats and the destruction of unwanted invasive species. The overall potential of this technique has not been explored yet, probably due to its limitations. In this review, we discussed cloning through SCNT, the preservation of endangered species through SCNT, and the use of modern genetical concepts in SCNT for the preservation of biodiversity.

The Dawn of Metal-Oxo Clusters as Artificial Proteases: From Discovery to the Present and Beyond.

The selective cleavage of peptide bonds in proteins is of paramount importance in many areas of the biological and medical sciences, playing a key role in protein structure/function/folding analysis, protein engineering, and targeted proteolytic drug design. Current applications that depend on selective protein hydrolysis largely rely on costly proteases such as trypsin, which are sensitive to the pH, ionic strength, and temperature conditions. Moreover, >95% of peptides deposited in databases are generated from trypsin digests, restricting the information within the analyzed proteomes. On the other hand, harsh and toxic chemical reagents such as BrCN are very active but cause permanent modifications of certain amino acid residues. Consequently, transition-metal complexes have emerged as smooth and selective artificial proteases owing to their ability to provide larger fragments and complementary structural information. In the past decade, our group has discovered the unique protease activity of diverse metal-oxo clusters (MOC) and pioneered a distinctive approach to the development of selective artificial proteases. In contrast to classical coordination complexes which often depend on amino acid side chains to control the regioselectivity, the selectivity profile of MOCs is determined by a complex combination of structural factors, such as the protein surface charge, metal coordination to specific side chains, and hydrogen bonding between the protein surface and the MOC scaffold.In this Account, we present a critical overview of our detailed kinetic, spectroscopic, and crystallographic studies in MOC-assisted peptide bond hydrolysis, from its origins to the current rational and detailed mechanistic understanding. To this end, reactivity trends related to the structure and properties of MOCs based on the hydrolysis of small model peptides and key structural aspects governing the selectivity of protein hydrolysis are presented. Finally, our endeavors in seeking the next generation of heterogeneous MOC-based proteases are briefly discussed by embedding MOCs in metal-organic frameworks or using them as discrete nanoclusters in the development of artificial protease-like materials (i.e., nanozymes). The deep and comprehensive understanding sought experimentally and theoretically over the years in aqueous systems with intrinsic polar and charged substrates provides a unique view of the reactivity between inorganic moieties and biomolecules, thereby broadly impacting several different fields (e.g., catalysis in biochemistry, inorganic chemistry, and organic chemistry).

Invariance of the r2-ln(F) relationship and attainable precision in ultrafast laser ablation experiments.

Pursuing ever-smaller feature size in laser-based lithography is a research topic of vital importance to keep this technique competitive with other micro-/nano-fabrication methods. Features smaller than the diffraction-limited spot size can be obtained by "thresholding", which utilizes the deterministic nature of damage threshold with ultrashort laser pulses and is achieved by precisely tuning pulse energies so that only the central portion of the focal spot produces permanent modification. In this paper, we examine the formulation commonly used to describe thresholding and show that the relationship between feature size (r) and laser fluence (F) is invariant with respect to the nature of laser absorption. Verified by our experiments performed on metal, semiconductor, and dielectric samples, such invariance is used to predict the smallest feature size that can be achieved for different materials in a real-world system.

Clothing and body modification in the Hebrew Bible

AbstractDescriptions of clothing and body modification in the Hebrew Bible often communicate information about the wearers' identities, emotions, and changes of status. Dress studies is an interdisciplinary pursuit that has expanded greatly since the 1980s as part of a wider academic recognition that the human body is a primary site of cultural construction. Hebrew Bible scholars have increasingly recognized the value of this approach with regard to biblical texts and continue to explore its multifaceted dimensions. The studies to date include examinations of permanent body modifications in the Hebrew Bible: circumcision, scarification, tattooing, and piercing. Scholars have also analyzed temporary body modifications, such as styling or cutting the hair and applying cosmetics. Additionally, there are studies of the supplements added to the body, most notably clothing and jewelry. When examined in their social context, biblical descriptions of clothing and body modification reveal important information about the figures involved, the development of a narrative, and the ideologies of biblical writers.

Parental exposure to benzo(a)pyrene in the peripubertal period impacts reproductive aspects of the F1 generation in rats

Benzo(a)pyrene (BaP) is an ubiquitous environmental pollutant which can lead to adverse effects on male reproduction. However, the persistence of these changes on a multigenerational scale has not been sufficiently explored. This study evaluated if peripubertal exposure to BaP in male rats can induce reproductive impairment in offspring. Male rats received BaP at environmentally relevant doses (0, 0.1, 1, or 10 μg/kg/day) orally from post-natal (PND) 23–53. On PND 90, treated males were mated with non-treated females for obtaining the next generation (F1). The paternal exposure to BaP decreased the body weight of offspring on PND 1, 13 and 22, as well as it provoked a reduction in the relative anogenital distance of the males. This exposure also brought forward the onset of puberty, evidenced by an earlier vaginal opening and first estrous in females of the lowest dose group and by a delay in the testicular descent and preputial separation ages in males. The males presented a decrease in the daily sperm production and a disrupted sperm morphology. Furthermore, the testicular histology was altered, evidenced by a reduction in the Leydig cell numbers and in the seminiferous tubules diameter, as well as a disrupted seminiferous tubules staging. The estrous cyclicity and some fertility parameters were changed in the females, as well as alterations in the ovary and uterus histology were observed. BaP compromised several reproductive parameters of the F1 generation, suggesting that peripubertal exposure to this compound provokes permanent modifications in male germ line of F0 generation.

Indoor Camping in Fortified Heritage Buildings: A New Way of Sustainable Tourism Valorization

Indoor camping is an innovative, sustainable model of accommodation, the least intrusive one in solid facilities. Its temporary tourism function demands almost no additional construction work, meaning no permanent modification of space is needed for tourism purposes. Fortifications and defence buildings are recognised as valuable cultural attractions and present an anthropogenic resource with potential for touristic valorisation, both as sightseeing facilities as well as accommodation facilities. This paper explores the connection between the requirements of heritage protection of fortifications and the requirements of the application of indoor camping in these fortifications. The purpose of this paper is to help conserve fortifications by providing funding for their maintenance with the application of this innovative accommodation model respecting the principles of sustainability and health and safety standards in post-Covid tourism. The goal is to provide a general framework that could reconcile tourism businesses on one side and conservators on the other. The main scientific contribution is summarised in the framework of adequate implementation of indoor camping in fortified buildings according to conservators’ requirements. The interview technique was used to assess this. The authors found that indoor camping can be a suitable accommodation model in fortified buildings. The key limitation of the model is based on the fact that an individual approach is necessary for every heritage building, as well as fortification, since they are unique. Therefore, each application of an indoor camping model should receive a proper conservators’ permit before the entrepreneurship venture. Furthermore, the opinions of key stakeholders were also investigated.

The Relationship Between Microbiology as a Science and the Microbiology Subject

From ancient times to the Renaissance, science constitutes a knowledge that is based on the contemplation of nature. The use of the preceding results, their permanent modification, the crossing of information, models, is what constitutes science, in a cumulative tradition of knowledge and practices. The objective of this work is to contribute to the knowledge of the history of microbiology and its role in the education and preparation of future doctors. Our knowledge of microbes has had a negative side, since they are the causative agents of infectious diseases, contamination and deterioration of food, materials, etc. After the golden age of Bacteriology, inaugurated by great figures such as Pasteur and Koch, Microbiology remained for some time a descriptive and applied discipline, closely interwoven with Medicine, and with a development parallel to that of Chemistry, which it would contribute several fundamental methodological advances. Our knowledge of microbes has had a negative side, fear, since they are the causative agents of infectious diseases, and of contamination and deterioration of food, materials, etc. However, we are beginning to realize that we are completely dependent on microbial life. Life not only began with prokaryotic microorganisms, but the continuity of the very existence of life on Earth rests with them. The Microbiology subject is essential to understand the functioning of ecosystems and the interactions between the atmospheric, aquatic and terrestrial environment. Our objective is that, after taking the course, the student has acquired a global vision about the microbial world, the impact of microorganisms in the environment and their possible use in technological processes associated with the environment. We emphasize the importance of Microbiology in medicine and other related careers.

Efficient Transient Gene Knock-down in Tobacco Plants Using Carbon Nanocarriers.

Gene knock-down in plants is a useful approach to study genotype-phenotype relationships, render disease resistance to crops, and enable efficient biosynthesis of molecules in plants. Small interfering RNA (siRNA)-mediated gene silencing is one of the most common ways to achieve gene knock-down in plants. Traditionally, siRNA is delivered into intact plant cells by coding the siRNA sequences into DNA vectors, which are then delivered through viral and/or bacterial methods. In this protocol, we provide an alternative direct delivery method of siRNA molecules into intact plant cells for efficient transient gene knock-down in model tobacco plant, Nicotiana benthamiana, leaves. Our approach uses one dimensional carbon-based nanomaterials, single-walled carbon nanotubes (SWNTs), to deliver siRNA, and does not rely on viral/bacterial delivery. The distinct advantages of our method are i) there is no need for DNA coding of siRNA sequences, ii) this abiotic method could work in a broader range of plant species than biotic methods, and iii) there are fewer regulatory complications when using abiotic delivery methods, whereby gene silencing is transient without permanent modification of the plant genome. Graphic abstract.

Experienced general practitioners' and practice nurses' views on the older-person health assessment forms.

Objective Health assessments (HAs) are available annually for community-dwelling older people: the 75+HA for non-Indigenous Australians aged ≥75 years and the 55+IHA for Indigenous Australians aged ≥55 years. Medicare requires general practitioners (GPs) to cover the items within the relevant HA form. This study explored the views of experienced GPs and practice nurses (PNs) towards the older-person HA forms. Methods Thirty-nine experienced GPs and PNs responded to an online questionnaire. Results In this study, experienced GPs and PNs suggested that current items within the 75+HA Medicare-provided guideline form need reviewing, such as those relating to psychological function, medication and exercise and falls. There were also recommendations to consider including items consistently across both the 55+IHA and 75+HA and to include new items, such as personal alarms, loneliness, support networks, spiritual health, musculoskeletal diseases, whether other screening is up to date and future planning. Many parts of the HA were deemed irrelevant or condescending to 'well' older Australians, so should be optional. Healthcare professionals also requested reintroducing conducting the HA at the community-dwelling patient's home. User-friendly integrated forms would improve healthcare professionals' time management and provide better communication with patients and carers, and create greater opportunities for multidisciplinary referral processes, as well as provide linkages to MyAgedCare and myHealthRecord. Conclusion Capturing the views of healthcare professionals towards older-person HA forms generated suggested improvements. The adoption of these suggestions would elicit more holistic health information for older Australians. What is known about the topic? Annual HAs are available for older Australians (75+HAs and 55+IHAs). Medicare requires GPs cover items within their prescribed HA form. The 75+HAs and 55+IHAs allow for the monitoring of health problems specific to community-dwelling older people, which may be difficult to address in the time frames of a standard GP consultation; however, there is very little research on the experiences of health professionals regarding the conditions required to be assessed within the HAs. What does this paper add? This study examined the views of experienced GPs and PNs to identify potential changes to the current procedures. Capturing the views of healthcare professionals towards older-person HA forms generated important suggested improvements, such as reviewing psychological function, medication, exercise and falls items. There were recommendations to include items across both the 55+IHA and 75+HA and new items, such as personal alarms, loneliness, support networks, spiritual health, musculoskeletal diseases assessments, future planning and whether the patient's screening is up to date. What are the implications for practitioners? The experienced GPs and PNs in this study suggested significant additions and revisions to the current HA forms. The incorporation of these suggestions should lead to permanent modifications of the current forms to make them more relevant and appropriate for older Australians, but the challenge for implementation is how these additional items would be funded.

An Easy-to-Use Socket-Suspension System Monitor for Lower Limb Amputees

Prosthetic sockets and the related suspension systems play key roles in functional restoration for individuals with limb loss; a good fit of the socket-suspension systems (SSSs) is critical to avoid unexpected skin breakdown. However, maintaining a good fit between the limb and SSS is challenging due to daily volume changes in the residual limb. In clinical practice, the fit of the SSS is monitored only through haptic feedback from the user. While important, this subjective feedback is often unreliable and inaccurate. Several automatic SSS monitoring approaches have been proposed, but widespread adoption has been limited by related high costs and difficulty of use. To address these issues, we designed a wearable SSS monitor that can be adopted for any SSS using liners without requiring permanent modifications of the SSS. Using a tiny magnetic disk as a marker, we were able to monitor the relative displacement between the residual limb (represented by the liner) and the prosthetic socket along the proximal-distal direction using field orientation measurement sensors. We conducted bench tests to validate the high accuracy of the wearable SSS monitor and demonstrated the capability of tracking SSS fit changes during locomotion without permanent modification of the SSS.

Using Genericity and Reflection to Create a Declarative Elaboration Logger for Large Scale Real-time Embedded Ada Systems

Large complex Ada real-time embedded software systems typically contain critical order-dependent unit elaboration sequences executed during system startup. However, software enhancements and maintenance activities can inadvertently alter unit dependencies and produce grammatically legal yet semantically illegal elaboration sequence orders. Location of failure during system boot-up is traditionally difficult to diagnose, as large legacy systems typically do not contain trace logging capabilities in unit elaboration regions. Additionally, the Ada language does not provide constructs for executing non-declarative expressions in package specifications, making unit specification elaboration trace logging impossible. Typical system boot failure diagnosis is a combination of educated guesswork, ad-hoc insertions of trace logging code at suspicious locations, and/or the creation of large quantities of temporary trace logging code, resulting in time-consuming iterations of altered builds, system execution, and subsequent analysis. This paper describes a Generic Reflective Declarative Elaboration Logger (GRDEL) which can be used in non-traditional source code locations anywhere declarations are grammatically legal. The tool provides previously unavailable Ada package Specification elaboration trace logging, formal run-time discovery of arbitrarily deeply nested unit name usage locations, implicit generation of trace information during separate logging instance creations, and facilitation of electronic code augmentation via identically formed logging usage expressions, which can automate a repeatable and deterministic instrumentation of extremely large and complex systems with or without permanent source code modifications.

TREAT Early Arthralgia to Reverse or Limit Impending Exacerbation to Rheumatoid arthritis (TREAT EARLIER): a randomized, double-blind, placebo-controlled clinical trial protocol

BackgroundWe present a study protocol for a randomized, double-blind, placebo-controlled trial that investigates the hypothesis if intervention in the symptomatic phase preceding clinical arthritis (clinically suspect arthralgia (CSA)) is effective in preventing progression from subclinical inflammation to clinically apparent persistent arthritis. Currently, rheumatoid arthritis (RA) can be recognized and diagnosed when arthritis (joint swelling) has become detectable at physical examination. Importantly, at this time, the immune processes have already matured, chronicity is established, and patients require long-standing treatment with disease-modifying anti-rheumatic drugs. The TREAT EARLIER trial studies the hypothesis that intervention in the symptomatic phase preceding clinical arthritis is more often successful in permanent disease modification because of less matured underlying disease processes.MethodsA two-level definition to identify patients that are prone to develop RA is used. First, patients should have CSA and recent-onset arthralgia (< 1 year) that is suspect to progress to RA according to the expertise of the treating rheumatologist. Second, patients need to have subclinical inflammation of the hand or foot joints at 1.5 T MRI. The trial aims to recruit 230 participants from secondary care hospital settings across the south-west region of The Netherlands. Intervention will be randomly assigned and includes a single-dose of intramuscular 120 mg methylprednisolon followed by methotrexate (increasing dose to 25 mg/week orally) or placebo (both; injection and tablets) over the course of 1 year. Thereafter, participants are followed for another year. The primary endpoint is the development of clinically detectable arthritis, either fulfilling the 2010 criteria for RA or unclassified clinical arthritis of ≥ 2 joints, which persists for at least 2 weeks. DMARD-free status is a co-primary endpoint. The patient-reported outcomes functioning, along with workability and symptoms, are key secondary endpoints. Participants, caregivers (including those assessing the endpoints), and scientific staff are all blinded to the group assignment.DiscussionThis proof-of-concept study is the logical consequence of pre-work on the identification of patients with CSA with MRI-detected subclinical joint inflammation. It will test the hypothesis whether intervention in patients in this early phase with the cornerstone treatment of classified RA (methotrexate) hampers the development of persistent RA and reduce the disease burden of RA.Trial registrationDutch Trial Register NL4599 (NTR4853). Registered on 20 October 2014

3153 – IMPACT OF SEPSIS ON EPIGENETIC REGULATION OF HEMATOPOIETIC STEM CELLS (HSC)

Sepsis is a systemic inflammatory over-response to microbial infection associated with high mortality rates. In addition, survivors of sepsis exhibit long-lasting effects of the disease, remaining immunosuppressed and at high risk for infections for the rest of their life. Hence, new therapies for sepsis are an unmet clinical need and novel ideas and approaches are needed. Using a murine model of severe sepsis induced by P. aeruginosa (P. aer.) bacteria or LPS, our group has previously reported that bone marrow (BM) responds to infections with a significant expansion of HSC associated with a blockage in their differentiation and inability to continuously generate mature neutrophils. As a result, the most critical defense against bacterial pathogens is suppressed, leading to profound neutropenia. Furthermore, when transplanted into healthy mice, HSC that have been exposed to a septic environment showed reduced ability to contribute to the myeloid lineage and to engraft at long-term, suggesting that they retain memory of the septic injury and maintain long-lasting changes. We hypothesize that the latters are due to sepsis-induced rapid and permanent epigenetic modifications in HSC, reshaping their transcriptional programs and affecting cell fate decisions and differentiation. To address our hypothesis, we challenged wild-type mice with P.aer. LPS and performed ATAC-seq on sorted HSC at 24 hrs or 108 hrs after challenge. Immunophenotypic analysis showed that HSC levels renormalized after 108 hr following their rapid expansion and differentiation arrest in response to LPS. However, alterations in the abundance and cell-cycle of myeloid progenitors and mature cells still persevered at long-term. Interestingly, ATAC-seq analysis revealed the persistence of euchromatic regions at 108 hrs from challenge in genomic regions involved in cell fate decisions and cell-cycle, suggesting that inflammation has long-lasting effects on epigenetic regulation, despite apparent HSC phenotypic normalization. Differently from previous works, our studies focus on epigenetic changes at HSC level, during the initial stages of the disease, when opportunity for effective therapeutic intervention may still be available. Our ultimate goal is to identify strategies to re-direct "septic" HSC to a normal differentiation program, thus allowing an efficient innate host response.

Modern specific of Japanese urbanism as a result of the country’s cultural mentality distinctiveness

The article analyzes the urbanistic experience of modern Japan in terms of the country’s architectural history. The following features of Japanese modern urbanistic are highlighted: dynamism and mobility – the ability of permanent development and modification (so called architectural metabolism); communicativeness of city space; the cohesion of the concepts of interior and exterior; freedom and novelty of architectural forms; humane and psychological comfort of urban environment. Based on the analysis of the unique climatic and seismological conditions of Japan, its geographical, ethnic and historical characteristics, it is revealed that all indicated above modern urbanistic features originate in the prerequisites of Japanese mentality formation directly related to architectural traditions. Since ancient times, Japanese culture has easily adapted to new circumstances modifying both obsolete traditional phenomena and foreign influences to a fundamentally different level. During the industrial revolution, thanks to the active borrowing of European and American engineering experience, such an approach leads in Japan to a qualitative leap of urbanism and design, forming an imaginary gap between the historical and modern architecture. In reality, urban planning and architecture of modern Japan demonstrate a deep genetic connection with historical tradition, which is present here as a permanent global evolutionary vector of ideas.

Peace missions as an element of international security

Peace missions in the modern world are inextricably linked to the political and social processes taking place in specific regions of the globe. When looking closer to the more than fifty-year history of international peacekeeping operations, it should be noted that as time passes, they undergo constant transformations. Their types, goals, and ways of implementation are changing. That is because the environment in which such operations are carried out is changing. They are also transforming the goals and priorities of local and international communities. Permanent modification is also subject to threats in the modern world. Peace missions are conducted under ever-changing social, economic, and political conditions. They must be flexible so that they can adapt to new challenges. Success is never guaranteed because the tasks related to maintaining peace are carried out in challenging conditions. The success of the peace mission depends on many factors, such as the composition of the peacekeeping mission (military personnel, police, civilian employees), logistical support, entrusted tasks and the environment in which the peace mission operates.

A two-objective design optimisation approach for blending repairs of damaged compressor blisks

The blending of compressor blades leads to a permanent modification of the blade geometry. According to these geometric changes, the modal properties of refurbished blades will generally differ from the nominal blade design. Currently, the structural integrity of refurbished blades is maintained by only allowing blends within predefined geometric limits, where the final geometry of the blend is based on a case-by-case decision made by the technician.This work contributes to repair decisions by utilising multi-objective optimisation methods to find structurally optimised blend designs. A parameterised blending model is introduced to uniquely specify the repair design for any blade geometry. Blend designs are analysed systematically by linking the blending model with the Finite Element model of a bladed sector. The influence of the blending shape is evaluated by means of blade-alone frequencies and vibration mode shapes. A two-objective optimisation problem is derived from the frequency tuning of blended blades. The first objective results from the deviation of natural frequencies from the nominal ones, the second objective considers the proximity of natural frequencies to resonance frequencies. Moreover, the approach is applied to one bladed sector of a compressor blisk. The sensitivities of the blend geometry regarding the first six vibration modes are studied. Two damage patterns at different positions at the leading edge of the blade are chosen to exemplarily demonstrate the capability of the proposed approach. For both damage patterns, the set of Pareto optimal solutions is found using Global Pattern Search. The courses of the Pareto frontiers clearly differ and are identified to be specific for each damage pattern. Depending on the damage pattern, discontinuous as well as continuous Pareto frontiers are determined. Providing Pareto optimal solutions for repair designs, the developed approach can be understood as a valuable complement to purely experience-based design decisions.

Effect analysis on energy efficiency enhancement of controlled cylinder liner temperatures in marine diesel engines with model based approach

In recent years, growing interest in engine efficiency, because of international regulations in the maritime sector, necessitates studies about new operational techniques. Ships have been operating at reduced speeds in recent years and, the liner temperatures of marine diesel engines vary significantly at reduced loads, which increase the heat loss from main engine. The research focuses on revealing the energy efficiency enhancement potential by decreasing heat loss through jacket water during reduced loads without any permanent modification. The heat loss reduction is achieved by means of higher coolant (glycol–water mixture) temperatures, to keep the liner temperatures at their maximum permissible temperatures. The methodology is calculating the energy balance and efficiency increment at reduced loads of main engine by modelling. The model have been validated with the digital twin of a two-stroke Sulzer-12RTA84C marine diesel engine. The simulated results comprise in-cylinder pressures, exhaust gas temperature and pressure, scavenge pressure, engine speed, turbo-charger, indicated power and heat transfer rate. Liner temperatures, affecting the heat transfer rate, are investigated in variable operating loads of the main engine. The study shows that keeping the liner temperature of the engine at the maximum continuous rating’s temperature, has respectable efficiency advantages under different operating loads. 0.5% reduction in fuel consumption could be achieved, coming with 127.8 tons fuel and 398 tons CO2 reduction in a year. Additionally, waste heat recovery system calculations were carried out and additional 48.8 tons of fuel could be saved in the generation of electricity. In total 176.6 tons of fuel and 550 tons of CO2 emission reduction could be achieved. As a result, the controlled cylinder wall temperatures can be considered as one of the methods to solve the efficiency and emission problems in ships in the near future.

Effect of ‘water-in-salt’ electrolytes in the electrochemical hydrogen evolution reaction of carbon nanotubes

Super-concentrated electrolytes based electrochemistry is an emerging trend in electrochemical processes (Borodin et al 2020 Joule 4 69–100), where unprecedented properties were reported recently. Such an ‘electrolyte engineered approach’ can find applicabilities in modern batteries and catalysis. Here we report the use of such high concentration lithium ions (Li+) containing electrolytes for enhancing the electrocatalytic hydrogen evolution (HER) performance of carbon nanotubes (CNTs), contrary to that observed with platinum. Different types of CNTs, namely metallic multi-wall (MWCNTs) and semiconducting single wall (SWCNTs), are tested towards the Li+ effect in the HER performance and similar trends are obtained. Further, different lithium salts having counter ions such as TFSI−, OTf−, ClO4−, Cl−, and OH− are also tested to verify the mechanism, and the role of Li+ in the HER augmentation of CNTs is established. The studies are conducted in different electrolytes having a range of pH values too (0–13), and the cation induced CNT’s HER enhancement is generalized. This study shows that even the sluggish HER kinetics of CNTs in alkaline medium can be augmented by such an electrolyte engineering approach where catalyst’s surface do not undergo any permanent modification. Further, such electrodes are found to be highly stable towards the long term HER performance.

Does Temporary Mortgage Assistance for Unemployed Homeowners Reduce Longer Term Mortgage Default? An Analysis of the Hardest Hit Fund Program

Economic crisis like the Great Recession and the COVID pandemic prompt government intervention to stabilize homeowners and housing markets. During the Great Recession, the primary intervention was permanent loan modifications, with mixed evidence of success. The COVID pandemic spurred a more targeted but temporary intervention--mortgage payment relief for unemployed homeowners. Little is known about the long term effectiveness of temporary mortgage assistance on homeowner outcomes. This paper leverages data on the U.S. Department of Treasury’s Hardest Hit Fund (HHF) program to analyze the longer term effects of temporary mortgage payment subsidies on mortgage default. Our primary empirical strategy exploits the fact that some states were not eligible to offer an HHF program and that certain Metropolitan Statistical Areas (MSAs) encompass jurisdictions in both HHF and non-HHF states. In an alternative specification, we model selection into HHF directly, exploiting lender variation in program participation as an instrument. Our results indicate that receipt of HHF leads to a 40 percent reduction in the probability of mortgage default and foreclosure through four years post assistance. We estimate heterogeneous effects for different at risk populations and discuss implications for policy.

High-Temperature Oxidation of Heavy Boron-Doped Diamond Electrodes: Microstructural and Electrochemical Performance Modification.

In this work, we reveal in detail the effects of high-temperature treatment in air at 600 °C on the microstructure as well as the physico-chemical and electrochemical properties of boron-doped diamond (BDD) electrodes. The thermal treatment of freshly grown BDD electrodes was applied, resulting in permanent structural modifications of surface depending on the exposure time. High temperature affects material corrosion, inducing crystal defects. The oxidized BDD surfaces were studied by means of cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM), revealing a significant decrease in the electrode activity and local heterogeneity of areas owing to various standard rate constants. This effect was correlated with a resultant increase of surface resistance heterogeneity by scanning spreading resistance microscopy (SSRM). The X-ray photoelectron spectroscopy (XPS) confirmed the rate and heterogeneity of the oxidation process, revealing hydroxyl species to be dominant on the electrode surface. Morphological tests using scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that prolonged durations of high-temperature treatment lead not only to surface oxidation but also to irreversible structural defects in the form of etch pits. Our results show that even subsequent electrode rehydrogenation in plasma is not sufficient to reverse this surface oxidation in terms of electrochemical and physico-chemical properties, and the nature of high-temperature corrosion of BDD electrodes should be considered irreversible.