Parthenogenesis is self-destructive for scaled reptiles.

Parthenogenesis is rare in nature. With 39 described true parthenogens, scaled reptiles (Squamata) are the only vertebrates that evolved this reproductive strategy. Parthenogenesis is ecologically advantageous in the short term, but the young age and rarity of parthenogenetic species indicate it is less advantageous in the long term. This suggests parthenogenesis is self-destructive: it arises often but is lost due to increased extinction rates, high rates of reversal or both. However, this role of parthenogenesis as a self-destructive trait remains unknown. We used a phylogeny of Squamata (5388 species), tree metrics, null simulations and macroevolutionary scenarios of trait diversification to address the factors that best explain the rarity of parthenogenetic species. We show that parthenogenesis can be considered as self-destructive, with high extinction rates mainly responsible for its rarity in nature. Since these parthenogenetic species occur, this trait should be ecologically relevant in the short term.

Advancing DNA Steganography with Incorporation of Randomness.

DNA has become a promising candidate as a future data storage medium; this makes DNA steganography indispensable in DNA data security. PCR primers are conventional secret keys in DNA steganography. Brute force testing of different primers will be extremely time consuming, and practically unaffordable when high-throughput sequencing is used. However, the encrypted information can be sequenced and read once the primers are intercepted. A new steganography approach is needed to make the DNA-encoded information safer, if not unhackable. Mixing information-carrying DNA with a partially degenerated DNA library containing single or multiple restriction sites, we have built an additional protective layer that can be removed by desired restriction enzymes as secondary secret keys. As PCR is inevitable for reading DNA-encrypted information, heating will cause reshuffling and generate endonuclease-resistant mismatched duplexes, especially for DNA with high sequence diversity. Consequently, with the incorporation of randomness, DNA steganography possesses both quantum key distribution (QKD)-like function for detecting PCR by an interceptor and a self-destructive property. It is noteworthy that the background noise generated through the protective layer is independent from any sequencing technology including Sanger and high-throughput sequencing. With a DNA ink incorporating the steganography, we have shown that the authenticity of a piece of writing can be confirmed only by authorized persons with knowledge of all embedded keys.

Self-Destruction of Cancer Induced by Ag2 S Amorphous Nanodots.

Studies on distinctive performances and novel applications of amorphous inorganic nanomaterials are becoming attractive. Herein, Ag2 S amorphous and crystalline nanodots (ANDs and CNDs) are prepared via facile methods. In vitro and in vivo studies indicate that Ag2 S ANDs, rather than CNDs, can induce the self-destruction of tumors, which can be attributed to their distinctive chemical properties, e.g., the higher electrochemical active surface area and lower redox potential well matching with the redox reaction requirement in the tumor microenvironment. Ag2 S ANDs can be oxidized by intracellular reactive oxygen species (ROS) to release Ag+ , which further stimulates high generation of intracellular ROS. This mutual stimulation damages the mitochondria, induces apoptosis, and leads to the self-destruction of the tumor. Moreover, Ag2 S ANDs do not show observable in vitro and in vivo side effects. These findings provide a promising self-destructive strategy for cancer therapy by utilizing distinctive chemical properties of inorganic nanomaterials, while avoiding complicated external assistance.

Self-Destructive Structural Color Liquids for Time-Temperature Indicating.

Vaccines are undoubtedly a powerful weapon in our fight against global pandemics, as demonstrated in the recent COVID-19 case, yet they often face significant challenges in reliable cold chain transport. Despite extensive efforts to monitor their time-temperature history, current time-temperature indicators (TTIs) suffer from limited reliability and stability, such as difficulty in avoiding human intervention, inapplicable to subzero temperatures, narrow tracking temperature ranges, or susceptibility to photobleaching. Herein, we develop a class of structural color materials that harnesses dual merits of fluidic nature and structural color, enabling thermal-triggered visible color destruction based on triggering agent-diffusion-induced irreversible disassembly of liquid colloidal photonic crystals for indicating the time-temperature history of the cold chain transport. These self-destructive structural color liquids (SCLs) exhibit inherent irreversibility, superior sensitivity, tunable self-destructive time (minutes to days), and a wide tracking temperature range (-70 to +37 °C). Such self-destructive SCLs can be conveniently packaged into flexible TTIs for monitoring the storage and exposure status of diverse vaccines via naked-eye inspection or mobile phone scanning. By overcoming the shortcomings inherent in conventional TTIs and responsive photonic crystals, these self-destructive SCLs can increase their compatibility with cold chain transport and hold promise for the development and application of the next-generation intelligent TTIs and photonic crystals.

Information self-destruction module design based on micro thermoelectric power generation and energetic materials.

Information self-destruction modules (ISDMs) play a vital role in the information security area. In this paper, an ISDM based on the integration of a micro-thermoelectric generation mechanism (M-TEGM) with energetic materials (EMs) is proposed. On the basis of energy conversion relationship, an open-loop electromotive force is induced, and this energy will drive the EMs to release the detonation wave and realize information storage module self-destruction. During the tests, under the temperature difference (100 K), the open-loop electromotive force (3.86 V) is induced by the M-TEGM and can drive the EMs (0.37 mg copper azide) to generate a detonation wave (GPa) in 3.4 µs, which can physically destroy the information storage modules. This ISDM has advantages that include rapid response times, low drive energy compared with traditional information security technology.

A High-Functional-Density Integrated Inertial Switch for Super-Quick Initiation and Reliable Self-Destruction of a Small-Caliber Projectile Fuze.

With the aim of achieving the combat technical requirements of super-quick (SQ) initiation and reliable self-destruction (SD) of a small-caliber projectile fuze, this paper describes a high-functional-density integrated (HFDI) inertial switch based on the "ON-OFF" state transition (i.e., almost no terminal ballistic motion). The reliable state switching of the HFDI inertial switch is studied via elastic-plastic mechanics and verified via both simulations and experiments. The theoretical and simulation results indicate that the designed switch can achieve the "OFF-ON" state transition in the internal ballistic system, and the switch can achieve the "ON-OFF" state transition in the simulated terminal ballistic system within 8 µs or complete the "ON-OFF" state transition as the rotary speed sharply decreases. The experimental results based on the anti-target method show the switch achieves the "ON-OFF" state transition on the µs scale, which is consistent with the simulation results. Compared with the switches currently used in small-caliber projectile fuzes, the HFDI inertial switch integrates more functions and reduces the height by about 44%.

Research on Energetic Micro-Self-Destruction Devices with Fast Responses.

Information self-destruction devices represent the last protective net available to realize information security. The self-destruction device proposed here can generate GPa-level detonation waves through the explosion of energetic materials and these waves can cause irreversible damage to information storage chips. A self-destruction model consisting of three types of nichrome (Ni-Cr) bridge initiators with copper azide explosive elements was first established. The output energy of the self-destruction device and the electrical explosion delay time were obtained using an electrical explosion test system. The relationships between the different copper azide dosages and the assembly gap between the explosive and the target chip with the detonation wave pressure were obtained using LS-DYNA software. The detonation wave pressure can reach 3.4 GPa when the dosage is 0.4 mg and the assembly gap is 0.1 mm, and this pressure can cause damage to the target chip. The response time of the energetic micro self-destruction device was subsequently measured to be 23.65 µs using an optical probe. In summary, the micro-self-destruction device proposed in this paper offers advantages that include low structural size, fast self-destruction response times, and high energy-conversion ability, and it has strong application prospects in the information security protection field.

Research on Insurance Method for Energetic Materials on Information Self-Destruction Chips.

Detonation waves released by energetic materials provide an important means of physical self-destruction (Psd) for information storage chips (ISCs) in the information insurance field and offer advantages that include a rapid response and low driving energy. The high electrical sensitivity of energetic materials means that they are easily triggered by leakage currents and electrostatic forces. Therefore, a Psd module based on a graphene-based insurance actuator heterogeneously integrated with energetic materials is proposed. First, the force-balance relation between the electrostatic van der Waals force and the elastic recovery force of the insurance actuator's graphene electrode is established to realize physical isolation and an electrical interconnection between the energetic materials and the peripheral electrical systems. Second, a numerical analysis of the detonation wave stress of the energetic materials in the air domain is performed, and the copper azide dosage required to achieve reliable ISC Psd is obtained. Third, the insurance actuator is prepared via graphene thin film processing and copper azide is prepared via an in situ reaction. The experimental results show that the energetic materials proposed can release physical isolation within 14 µs and can achieve ISC Psd under the application of a voltage signal (4.4-4.65 V). Copper azide (0.45-0.52 mg) can achieve physical damage over an ISC area (23.37-35.84 mm2) within an assembly gap (0.05-0.25 mm) between copper azide and ISC. The proposed method has high applicability for information insurance.

Psychopathological and Neurobiological Overlap Between Anorexia Nervosa and Self-Injurious Behavior: A Narrative Review and Conceptual Hypotheses.

Empirical evidence and clinical observations suggest a strong -yet under acknowledged-link between anorexia nervosa (AN) and non-suicidal self-injurious behavior (NSSI). By reviewing the literature on the psychopathology and neurobiology of AN and NSSI, we shed light on their relationship. Both AN and NSSI are characterized by disturbances in affect regulation, dysregulation of the reward circuitry and the opioid system. By formulating a reward-centered hypothesis, we explain the overlap between AN and NSSI. We propose three approaches understanding the relationship between AN and NSSI, which integrate psychopathology and neurobiology from the perspective of self-destructiveness: (1) a nosographical approach, (2) a research domain (RDoC) approach and (3) a network analysis approach. These approaches will enhance our knowledge of the underlying neurobiological substrates and may provide groundwork for the development of new treatment options for disorders of self-destructiveness, like AN and NSSI. In conclusion, we hypothesize that self-destructiveness is a new, DSM-5-transcending concept or psychopathological entity that is reward-driven, and that both AN and NSSI could be conceptualized as disorders of self-destructiveness.

Biologically Safe, Degradable Self-Destruction System for On-Demand, Programmable Transient Electronics.

The lifetime of transient electronic components can be programmed via the use of encapsulation/passivation layers or of on-demand, stimuli-responsive polymers (heat, light, or chemicals), but yet most research is limited to slow dissolution rate, hazardous constituents, or byproducts, or complicated synthesis of reactants. Here we present a physicochemical destruction system with dissolvable, nontoxic materials as an efficient, multipurpose platform, where chemically produced bubbles rapidly collapse device structures and acidic molecules accelerate dissolution of functional traces. Extensive studies of composites based on biodegradable polymers (gelatin and poly(lactic-co-glycolic acid)) and harmless blowing agents (organic acid and bicarbonate salt) validate the capability for the desired system. Integration with wearable/recyclable electronic components, fast-degradable device layouts, and wireless microfluidic devices highlights potential applicability toward versatile/multifunctional transient systems. In vivo toxicity tests demonstrate biological safety of the proposed system.

Suicide by crashing into a heavy vehicle: a focus group study of professional drivers.

Professional heavy vehicle drivers can experience a traumatic event at work when suicidal drivers deliberately crash into their vehicles or a pedestrian jumps in front of them. This study adopts a qualitative approach, aiming to gain an understanding about the psychological and other consequences that these crashes have for this occupational group. We organized a semi-structured focus group meeting with six drivers who reported experiencing a deliberate crash into their vehicle. The meeting was moderated by two psychologists. The participants reported that avoiding the crash was difficult. These events can have long-lasting effects on drivers' well-being although individual differences in the response to the event and coping strategies do exist. Participation in our meeting was regarded as a positive experience. This encourages us to believe that organizing similar meetings that allow drivers under the supervision of professionals to share their own experiences with those who experienced similar events, could perhaps be one way of providing support to such drivers who experienced a traumatic event at work.

Burnout syndrome among southern region orthopedic surgeons, Saudi Arabia.

BACKGROUND: Burnout is known as result of long term exposing to stress. There are some factors that may cause stress in physicians: nature of work, their training, their public image, their families and themselves. The person who has burnout syndrome (BOS) seems like to have tiredness, low energy, nervousness, and mentally unstable. The aim of the study is to assess the pattern and magnitude of burnout among orthopedic surgeons in southern region, Saudi Arabia. METHODOLOGY: A descriptive cross-sectional survey was applied targeting all orthopedic surgeons in 12 hospitals all southern region, Saudi Arabia during the period from December 2018 to April 2019. Data were collected using self-administered questionnaire that was developed by the researchers. The questionnaire included personal data. Burnout was assessed using Maslach Burnout Inventory Scale. RESULTS: A total sample of 107 orthopedic surgeons were included with their ages ranged from 25 to 65 years old with mean age of 38.1 ± 8.9 years. About 94% of the surgeons were males and 43.9% were Saudi. Generally, the surgeons recorded mean score for emotional exhaustion of 18.9 points out of 54 with mean score% of 35.1%. Regarding depersonalization, the surgeons had mean score % of 30.7% and had a score of 39.6% for personal accomplishment. CONCLUSIONS: The study revealed that all included physicians had moderate levels of burnout. Personal accomplishment was the highest level of burnout recorded. Health education sessions and periodic training is required to improve surgeons coping strategies to overcome burnout.

A Smart Nanoparticle-Laden and Remote-Controlled Self-Destructive Macrophage for Enhanced Chemo/Chemodynamic Synergistic Therapy.

Macrophages are known to penetrate tumor central hypoxic areas and hold great potential in cancer drug delivery. However, it remains a big challenge for current macrophage-based drug delivery systems (MDDSs) to prevent premature drug leakage and sufficiently release the therapeutics in tumor sites. Moreover, these MDDSs would encounter drug resistance and a hypoxic microenvironment in solid tumors, which further compromised their therapeutic efficacy. Herein, by internalizing a smart nanoparticle (doxorubicin (DOX)-loaded mesoporous carbon nanosphere wrapped with MnO2 shell) into macrophages, a macrophage vehicle (MMDM) is developed for enhanced chemo/chemodynamic synergistic therapy. The resulting MMDM could avoid premature drug leakage-induced cell dysfunction and maximally maintain cell viability. After accumulating in tumor tissues, the MMDM could be destroyed under a near-infrared laser to sufficiently release the nanoparticle out of the carrier macrophages. The released nanoparticle could then decompose H2O2 to generate O2 in the tumor microenvironment to relieve tumor hypoxia. Meanwhile, the MnO2 shell of the nanoparticle is reduced to Mn2+ by intracellular glutathione, triggering the release of DOX and subsequently resulting in an enhanced Mn2+-mediated Fenton-like reaction. This study provides an intriguing strategy to macrophage-based delivery systems for enhanced chemo/chemodynamic synergistic therapy.

Suicide by crashing into a heavy vehicle: Focus on professional drivers using in-depth crash data.

Objective: Road traffic suicides typically involve a passenger car driver crashing his or her vehicle into a heavy vehicle, because death is almost certain due to the large mass difference between these vehicles. For the same reason, heavy-vehicle drivers typically suffer minor injuries, if any, and have thus received little attention in the research literature. In this study, we focused on heavy-vehicle drivers who were involved as the second party in road suicides in Finland. Methods: We analyzed 138 road suicides (2011-2016) involving a passenger car crashing into a heavy vehicle. We used in-depth road crash investigation data from the Finnish Crash Data Institute. Results: The results showed that all but 2 crashes were head-on collisions. Almost 30% of truck drivers were injured, but only a few suffered serious injuries. More than a quarter reported sick leave following their crash. Injury insurance compensation to heavy-vehicle drivers was just above €9,000 on average. Material damage to heavy vehicles was significant, with average insurance compensation paid being €70,500. Three out of 4 truck drivers reported that drivers committing suicide acted abruptly and left them little opportunity for preventive action. Conclusions: Suicides by crashing into heavy vehicles can have an impact on drivers' well-being; however, it is difficult to see how heavy-vehicle drivers could avoid a suicide attempt involving their vehicle.

Suicide by crashing into a heavy vehicle: Professional drivers' views.

Objective: Every profession has its own safety and health risks. In addition to the risk of being involved in a "normal" road crash, professional heavy vehicle drivers are at risk of becoming victims of people attempting suicide by crashing into their vehicles. Road suicides are not that rare, at least not in Finland, where they represent about 12% of all fatal road crashes. The purpose of this study was to survey professional heavy vehicle drivers about their experiences, views and opinions regarding road suicides.Methods: The sample included heavy vehicle drivers (N = 863) randomly recruited from a transport workers' union.Results: About 18% of the respondents reported a suspected suicide attempt of a motor vehicle driver crashing into their vehicle, with 15% of these (i.e.2.8% of the whole sample) also reporting a resulting crash. More than half of the respondents reported personally knowing another professional driver who had experienced a crash caused by a suicidal driver. Almost 80% of the drivers reported being afraid that someone would attempt suicide by crashing into their vehicle; however, thinking about such a possibility produces a level of anxiety in less than half of all respondents. Most respondents agreed about the challenges of avoiding a crash if somebody deliberately drives their car towards their vehicle.Conclusion: Heavy vehicle drivers perceive road suicides as an occupational risk in their profession. We discuss possible preventive measures against suicide attempts by crashing into a heavy vehicle.

The Transcription Factor Tcf1 Contributes to Normal NK Cell Development and Function by Limiting the Expression of Granzymes.

The transcription factor Tcf1 is essential for the development of natural killer (NK) cells. However, its precise role has not been clarified. Our combined analysis of Tcf1-deficient and transgenic mice indicated that Tcf1 guides NK cells through three stages of development. Tcf1 expression directed bone marrow progenitors toward the NK cell lineage and ensured the survival of NK-committed cells, and its downregulation was needed for terminal maturation. Impaired survival of NK-committed cells was due to excessive expression of granzyme B (GzmB) and other granzyme family members, which induced NK cell self-destruction during maturation and following activation with cytokines or target cells. Mechanistically, Tcf1 binding reduced the activity of a Gzmb-associated regulatory element, and this accounted for the reduced Gzmb expression in Tcf1-expressing NK cells. These data identify an unexpected requirement to limit the expression of cytotoxic effector molecules for the normal expansion and function of NK cells.