Multiple Unfolded Protein Response pathways cooperate to link cytosolic dsDNA release to Stimulator of Interferon Gene (STING) activation.

The double-stranded DNA (dsDNA) sensor STING has been increasingly implicated in responses to "sterile" endogenous threats and pathogens without nominal DNA or cyclic di-nucleotide stimuli. Previous work showed an endoplasmic reticulum (ER) stress response, known as the unfolded protein response (UPR), activates STING. Herein, we sought to determine if ER stress generated a STING ligand, and to identify the UPR pathways involved. Induction of IFN-ß expression following stimulation with the UPR inducer thapsigargin (TPG) or oxygen glucose deprivation required both STING and the dsDNA-sensing cyclic GMP-AMP synthase (cGAS). Furthermore, TPG increased cytosolic mitochondrial DNA, and immunofluorescence visualized dsDNA punctae in murine and human cells, providing a cGAS stimulus. N-acetylcysteine decreased IFN-ß induction by TPG, implicating reactive oxygen species (ROS). However, mitoTEMPO, a mitochondrial oxidative stress inhibitor did not impact TPG-induced IFN. On the other hand, inhibiting the inositol requiring enzyme 1 (IRE1) ER stress sensor and its target transcription factor XBP1 decreased the generation of cytosolic dsDNA. iNOS upregulation was XBP1-dependent, and an iNOS inhibitor decreased cytosolic dsDNA and IFN-ß, implicating ROS downstream of the IRE1-XBP1 pathway. Inhibition of the PKR-like ER kinase (PERK) pathway also attenuated cytoplasmic dsDNA release. The PERK-regulated apoptotic factor Bim was required for both dsDNA release and IFN-ß mRNA induction. Finally, XBP1 and PERK pathways contributed to cytosolic dsDNA release and IFN-induction by the RNA virus, Vesicular Stomatitis Virus (VSV). Together, our findings suggest that ER stressors, including viral pathogens without nominal STING or cGAS ligands such as RNA viruses, trigger multiple canonical UPR pathways that cooperate to activate STING and downstream IFN-ß via mitochondrial dsDNA release.

Current safeguards, risk mitigation, and transparency measures of large language models against the generation of health disinformation: repeated cross sectional analysis.

OBJECTIVES: To evaluate the effectiveness of safeguards to prevent large language models (LLMs) from being misused to generate health disinformation, and to evaluate the transparency of artificial intelligence (AI) developers regarding their risk mitigation processes against observed vulnerabilities. DESIGN: Repeated cross sectional analysis. SETTING: Publicly accessible LLMs. METHODS: In a repeated cross sectional analysis, four LLMs (via chatbots/assistant interfaces) were evaluated: OpenAI's GPT-4 (via ChatGPT and Microsoft's Copilot), Google's PaLM 2 and newly released Gemini Pro (via Bard), Anthropic's Claude 2 (via Poe), and Meta's Llama 2 (via HuggingChat). In September 2023, these LLMs were prompted to generate health disinformation on two topics: sunscreen as a cause of skin cancer and the alkaline diet as a cancer cure. Jailbreaking techniques (ie, attempts to bypass safeguards) were evaluated if required. For LLMs with observed safeguarding vulnerabilities, the processes for reporting outputs of concern were audited. 12 weeks after initial investigations, the disinformation generation capabilities of the LLMs were re-evaluated to assess any subsequent improvements in safeguards. MAIN OUTCOME MEASURES: The main outcome measures were whether safeguards prevented the generation of health disinformation, and the transparency of risk mitigation processes against health disinformation. RESULTS: Claude 2 (via Poe) declined 130 prompts submitted across the two study timepoints requesting the generation of content claiming that sunscreen causes skin cancer or that the alkaline diet is a cure for cancer, even with jailbreaking attempts. GPT-4 (via Copilot) initially refused to generate health disinformation, even with jailbreaking attempts-although this was not the case at 12 weeks. In contrast, GPT-4 (via ChatGPT), PaLM 2/Gemini Pro (via Bard), and Llama 2 (via HuggingChat) consistently generated health disinformation blogs. In September 2023 evaluations, these LLMs facilitated the generation of 113 unique cancer disinformation blogs, totalling more than 40 000 words, without requiring jailbreaking attempts. The refusal rate across the evaluation timepoints for these LLMs was only 5% (7 of 150), and as prompted the LLM generated blogs incorporated attention grabbing titles, authentic looking (fake or fictional) references, fabricated testimonials from patients and clinicians, and they targeted diverse demographic groups. Although each LLM evaluated had mechanisms to report observed outputs of concern, the developers did not respond when observations of vulnerabilities were reported. CONCLUSIONS: This study found that although effective safeguards are feasible to prevent LLMs from being misused to generate health disinformation, they were inconsistently implemented. Furthermore, effective processes for reporting safeguard problems were lacking. Enhanced regulation, transparency, and routine auditing are required to help prevent LLMs from contributing to the mass generation of health disinformation.

Enhanced biodegradation of phenol by microbial collaboration: Resistance, metabolite utilization, and pH stabilization.

Mixed culture of microorganisms is an effective method to remove high concentration of phenol from wastewater. Currently, the mechanism of how microorganisms collaborate to enhance the biodegradation of phenol is still a challenge. In this study, the isolated Bacillus subtilis ZWB1 and Bacillus velezensis ZWB2 were co-cultured to enhance phenol biodegradation, and the mechanism of microbial collaboration was further explored. The co-culture of strains could significantly increase the rate (16.7 mg/L·h, 1000 mg/L) and concentration of phenol degradation (1500 mg/L), comparing with mono-culture of ZWB1 (4.2 mg/L·h, 150 mg/L) and ZWB2 (6.9 mg/L·h, 1000 mg/L), among which the highest degraded concentration of phenol for ZWB1 and ZWB2 was 150 and 1000 mg/L. Further, the mechanism of microbial collaboration to enhance phenol biodegradation was raised: the decrease of antioxidant enzymes, and increase of degrading enzymes and surfactants on content after co-culture, assisted the microorganisms in withstanding phenol; Bacillus subtilis ZWB1 used the metabolites of Bacillus velezensis ZWB2 to promote its growth, and further to degrade phenol rapidly; Bacillus subtilis ZWB1 alleviated the damage, which resulted from the pH drop (5.8) of the fermentation broth during phenol degradation that inhibited the growth and degraded ability of Bacillus velezensis ZWB2, making the pH of fermentation broth stable at 7. Metabolic analysis showed that co-culture of strains could produce more alkaline and buffering compounds and pairs, to stabilize pH and reduce the toxicity of acidity on ZWB2, thus increasing the degradation rate. This study explains the mechanism of microbial collaboration on phenol biodegradation from multiple perspectives, especially pH stabilization, which provides a theoretical basis for the degradation of pollutants by co-culture microorganisms.

Identification and Suppression of Majority Surface States in the Dry-Etched ß-Ga2O3.

Surface treatment after dry etching is vital to enhance the surface quality of the material and thus improve device performance. In this Letter, we identified the majority surface states induced by the dry etching of ß-Ga2O3 and optimized surface treatments to suppress these electrically active defects with the improved performance of Schottky barrier diodes. Transient spectroscopies suggested that the majority traps (EC-0.75 eV) related to divacancies (VGa-VO) were enhanced in the concentration of 3.37 × 1014 cm-3 by dry etching and reduced to 0.90 × 1014 cm-3 by the combined means of oxygen annealing and piranha solution treatment. The trap evolution is supported by the suppressed donor-acceptor pair radiative recombination related to oxygen vacancies, the improved carrier transport (negligible hysteresis current-voltage and unity ideality factor), and the reduced surface band bending. These findings provide a straightforward strategy to improve surface quality for the further performance improvement of Ga2O3 power diodes.

Ab Initio Design, Shaping, and Assembly of Free-Standing Silicon Nanoprobes.

Free-standing silicon nanoprobes (SiNPs) are critical tools for intracellular bioelectrical signal recording, while a scalable fabrication of these tiny SiNPs with ab initio geometry designs has not been possible. In this work, we demonstrate a novel growth shaping of slim Si nanowires (SiNWs) into SiNPs with sharp tips (curvature radii <300 nm), tunable angles of 30°, 60°, to 120° and even programmable triangle/circular shapes. A precise growth integration of orderly single, double, and quadruple SiNPs at prescribed locations enables convenient electrode connection, transferring and mounting these tiny tips onto movable arms to serve as long-protruding (over 4-20 µm) nanoprobes. Mechanical flexibility, resilience, and field-effect sensing functionality of the SiNPs were systematically testified in liquid nanodroplet and cell environments. This highly reliable and economic manufacturing of advanced SiNPs holds a strong potential to boost and open up the market implementations of a wide range of intracellular sensing, monitoring, and editing applications.

Tunicamycin-induced photoreceptor atrophy precedes degeneration of retinal capillaries with minimal effects on retinal ganglion and pigment epithelium cells.

Endoplasmic reticulum (ER) stress is recognized as a contributing factor to various ocular neurovascular pathologies including retinitis pigmentosa, glaucoma, and diabetic retinopathy (DR). ER stress in particular is implicated in the development of DR, which is significantly influenced by inflammation driven retinal vascular degeneration and dysfunction. Ultimately, loss of vision occurs if left untreated. However, the identity of the target cells and their temporal involvement in diabetes-mediated dysfunction need further investigation. Early diabetes-induced stress in photoreceptor cells is proposed as the driver of inflammatory mediated neurovascular changes during diabetes. Although tunicamycin induced ER stress results in photoreceptor loss, its consequences for retinal vascular degeneration and retinal ganglion (RGC) and pigment epithelium (RPE) cell loss remains unclear. Here we show intravitreal delivery of tunicamycin primarily induced ER stress in photoreceptor cells resulting in their loss by apoptosis. This was concomitant with induced expression of the unfolded protein response marker CHOP in these cells. We also demonstrated significant degeneration of retinal capillaries following the loss of photoreceptor cells with minimal impact on loss of RGC and RPE cells. However, activation of retinal microglial and Muller cells were noticeable. Thus, our data support the notion that ER stress mediated dysfunction and/or loss of photoreceptor cells in response to inflammation and oxidative stress could precede retinal vascular and neuronal dysfunction and degeneration.