Quantum Spin Probe of Single Charge Dynamics.

Electronic defects in semiconductors form the basis for emerging quantum technologies, but many defect centers are difficult to access at the single-particle level. A method for probing optically inactive spin defects would reveal semiconductor physics at the atomic scale and advance the study of new quantum systems. We exploit the intrinsic correlation between the charge and spin states of defect centers to measure the charge populations and dynamics of single substitutional nitrogen spin defects in diamond. By probing their steady-state spin population, read out at the single-defect level with a nearby nitrogen vacancy center, we directly measure the defect ionization-corroborated by first-principles calculations-an effect we do not have access to with traditional coherence-based quantum sensing.

CRISPR-Cas9 Mediated AGO2 Knockout inhibits tumorigenesis in human colorectal cancer cells.

AGO2 plays a vital role in small RNA-guided gene silencing, which has been implied in the tumorigenesis of different types of tumors. Fundamentally, increased expression of AGO2 protein is associated with cancer progression and metastasis. This study aims to investigate the molecular mechanism by which AGO2 promotes tumorigenesis in colorectal cancer (CRC). Databases were used to analyze the expression levels of AGO2 in CRC and confirmed by a quantitative reverse transcriptase-PCR (qRT-PCR) assay in CRC tissues and normal adjacent tissues collected from 25 CRC patients. CRISPR/Cas9-mediated genome editing was used to knockout the AGO2 in HCT116 cells as a model system for colorectal cancers. The cell proliferation, migration and invasion ability of HCT116 cells were detected by CCK-8 assay, Wound scratch assay and Transwell assay. Moreover, the quantities of miRNA binding with AGO2 were detected by RNA-Binding Protein Immunoprecipitation (RIP-Assay). We demonstrated that AGO2 was aberrantly high-expressed in 25 matched-tissue pairs of colorectal cancer and para-carcinoma tissue. The following functional experiments verified that knockout of AGO2 suppressed cell proliferation, migration and tumorigenesis to hamper the aggressiveness of CRC. Our study also suggests a possible link between AGO2 and miRNA in RISC. AGO2 was elevated in CRC and knockout of AGO2 suppressed proliferation and tumorigenicity of CRC cells. Moreover, RISC formation and the function of miRNAs are also subject to AGO2. AGO2 may be a meaningful target for CRC therapy.

METTL14 regulates CD8+T-cell activation and immune responses to anti-PD-1 therapy in lung cancer.

BACKGROUND: N6-methyladenosine (m6A) modification plays an important role in lung cancer. However, methyltransferase-like 14 (METTL14), which serves as the main component of the m6A complex, has been less reported to be involved in the immune microenvironment of lung cancer. This study aimed to analyze the relationship between METTL14 and the immune checkpoint inhibitor programmed death receptor 1 (PD-1) in lung cancer. METHODS: CCK-8, colony formation, transwell, wound healing, and flow cytometry assays were performed to explore the role of METTL14 in lung cancer progression in vitro. Furthermore, syngeneic model mice were treated with sh-METTL14 andan anti-PD-1 antibody to observe the effect of METTL14 on immunotherapy. Flow cytometry and immunohistochemical (IHC) staining were used to detect CD8 expression. RIP and MeRIP were performed to assess the relationship between METTL14 and HSD17B6. LLC cells and activated mouse PBMCs were cocultured in vitro to mimic immune cell infiltration in the tumor microenvironment. ELISA was used to detect IFN-γ and TNF-α levels. RESULTS: The online database GEPIA showed that high METTL14 expression indicated a poor prognosis in patients with lung cancer. In vitro assays suggested that METTL14 knockdown suppressed lung cancer progression. In vivo assays revealed that METTL14 knockdown inhibited tumor growth and enhanced the response to PD-1 immunotherapy. Furthermore, METTL14 knockdown enhanced CD8+T-cell activation and infiltration. More importantly, METTL14 knockdown increased the stability of HSD17B6 mRNA by reducing its m6A methylation. In addition, HSD17B6 overexpression promoted the activation of CD8+ T cells. CONCLUSION: The disruption of METTL14 contributed to CD8+T-cell activation and the immunotherapy response to PD-1 via m6A modification of HSD17B6, thereby suppressing lung cancer progression.

First-Principles Investigation of Near-Surface Divacancies in Silicon Carbide.

The realization of quantum sensors using spin defects in semiconductors requires a thorough understanding of the physical properties of the defects in the proximity of surfaces. We report a study of the divacancy (VSiVC) in 3C-SiC, a promising material for quantum applications, as a function of surface reconstruction and termination with -H, -OH, -F and oxygen groups. We show that a VSiVC close to hydrogen-terminated (2 × 1) surfaces is a robust spin-defect with a triplet ground state and no surface states in the band gap and with small variations of many of its physical properties relative to the bulk, including the zero-phonon line and zero-field splitting. However, the Debye-Waller factor decreases in the vicinity of the surface and our calculations indicate it may be improved by strain-engineering. Overall our results show that the VSiVC close to SiC surfaces is a promising spin defect for quantum applications, similar to its bulk counterpart.

Hyperthermia promotes exosome secretion by regulating Rab7b while increasing drug sensitivity in adriamycin-resistant breast cancer.

PURPOSE: To investigate the mechanism through which hyperthermia promotes exosome secretion and drug sensitivity in adriamycin-resistant breast cancer. MATERIALS AND METHODS: We first evaluated the effect of hyperthermia on adriamycin-resistant breast cancer viability and used transmission electron microscopy, nanoparticle tracking analysis, and a bicinchoninic acid kit to validate the effect of hyperthermia on exosome secretion. The effective targeting molecules and pathways changed by hyperthermia were explored by RNA microarray and verified in vitro. The adriamycin-resistant MCF-7/ADR cells co-incubated with the exosomes produced by MCF-7/ADR cells after hyperthermia were assessed. The uptake of exosomes by MCF-7/ADR cells after hyperthermia treatment was evaluated by confocal microscopy. Finally, the mechanism through which hyperthermia promotes exosome secretion by hyperthermia was determined. RESULTS: Hyperthermia significantly suppressed the growth of adriamycin-resistant breast cancer cells and increased drug sensitivity by upregulating FOS and CREB5, genes related to longer overall survival in breast cancer patients. Moreover, hyperthermia promoted exosome secretion through Rab7b, a small GTPase that controls endosome transport. The upregulated FOS and CREB5 antioncogenes can be transferred to MCF-7/ADR cells by hyperthermia-treated MCF-7/ADR cell-secreted exosomes. CONCLUSIONS: Our results demonstrated a novel function of hyperthermia in promoting exosome secretion in adriamycin-resistant breast cancer cells and revealed the effects of hyperthermia on tumor cell biology. These hyperthermia-triggered exosomes can carry antitumor genes to the residual tumor and tumor microenvironment, which may be more beneficial to the effects of hyperthermia. These results represent an exploration of the relationship between therapeutic strategies and exosome biology.

Thickness-dependent ultrafast charge-carrier dynamics and coherent acoustic phonon oscillations in mechanically exfoliated PdSe2 flakes.

Recently, palladium diselenide (PdSe2) has emerged as a promising material with potential applications in electronic and optoelectronic devices due to its intriguing electronic and optical properties. The performance of the device is strongly dependent on the charge-carrier dynamics and the related hot phonon behavior. Here, we investigate the photoexcited-carrier dynamics and coherent acoustic phonon (CAP) oscillations in mechanically exfoliated PdSe2 flakes with a thickness ranging from 10.6 nm to 54 nm using time-resolved non-degenerate pump-probe transient reflection (TR) spectroscopy. The results imply that the CAP frequency is thickness-dependent. Polarization-resolved transient reflection (PRTR) measurements reveal the isotropic charge-carrier relaxation dynamics and the CAP frequency in the 10.6 nm region. In addition, the deformation potential (DP) mechanism dominates the generation of the CAP. Moreover, a sound velocity of 6.78 × 103 m s-1 is extracted from the variation of the oscillation period with the flake thickness and the delay time of the acoustic echo. These results provide insight into the ultrafast optical coherent acoustic phonon and optoelectronic properties of PdSe2 and may open new possibilities for PdSe2 applications in THz-frequency mechanical resonators.

Vertical distributions of wintertime atmospheric nitrogenous compounds and the corresponding OH radicals production in Leshan, southwest China.

Ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) observations were operated from 02 to 21 December 2018 in Leshan, southwest China, to measure HONO, NO2 and aerosol extinction vertical distributions, and these were the first MAX-DOAS measurement results in Sichuan Basin. During the measurement period, characteristic ranges for surface concentration were found to be 0.26-4.58 km-1 and averaged at 0.93 km-1 for aerosol extinction, 0.49 to 35.2 ppb and averaged at 4.57 ppb for NO2 and 0.03 to 7.38 ppb and averaged at 1.05 ppb for HONO. Moreover, vertical profiles of aerosol, NO2 and HONO were retrieved from MAX-DOAS measurements using the Heidelberg Profile (HEIPRO) algorithm. By analysing the vertical gradients of pollutants and meteorological information, we found that aerosol and HONO are strongly localised, while NO2 is mainly transmitted from the north direction (city center direction). Nitrogen oxides such as HONO and NO2 are important for the production of hydroxyl radical (OH) and oxidative capacity in the troposphere. In this study, the averaged value of OH production rate from HONO is about 0.63 ppb/hr and maximum value of ratio between OH production from HONO and from (HONO+O3) is > 93% before12:00 in Leshan. In addition, combustion emission contributes to 26% for the source of HONO in Leshan, and we found that more NO2 being converted to HONO under the conditions with high aerosol extinction coefficient and high relative humidity is also a dominant factor for the secondary produce of HONO.

Significant changes in caecal microbial composition and metabolites of weaned piglets after protein restriction and succedent realimentation.

The present study aimed to investigate the effects of protein restriction and subsequent realimentation on caecal barrier function, caecal microbial composition and metabolites in weaned piglets. Thirty-six 28-day-old weaned piglets were randomly assigned to a control group and a treatment group. The piglets were fed diets containing 18.83% (normal) or 13.05% (low) of crude protein from the 1st to 14th day, after which all piglets were fed diets containing 18.83% of crude protein from the 15th to 28th day. The results showed that protein restriction increased caecal bacterial diversity and richness as well as the abundance of Ruminococcus 2, Faecalibacterium and Lachnospiraceae_uncultured, but reduced the abundance and the gene copies of Lactobacillus in the treatment group compared with the control group on day 14. Protein restriction also decreased the concentrations of isovaleric acid and total branched-chain fatty acids. During the succedent protein realimentation stage, the abundance of Ruminococcaceae UCG-014 and the concentrations of lactic acid, acetic acid, butyric acid and total short-chain fatty acids were increased in the treatment group on day 28. Furthermore, the ammonia concentration was reduced, while the gene mRNA levels of caecal barrier function were increased in the treatment group both on days 14 and 28. In conclusion, dietary protein restriction and realimentation could change caecal microbial composition and metabolites, and eventually influence caecal barrier function. The present study may provide a new insight into protein restriction and realimentation in weaned piglets.

Effects of early commercial milk supplement on the mucosal morphology, bacterial community and bacterial metabolites in jejunum of the pre- and post-weaning piglets.

OBJECTIVE: Sow milk (SM) may not be able to meet the piglet's nutritional needs in late lactation. Hence, this study was conducted to investigate the effects of early commercial milk (CM) supplement on the mucosal morphology, bacterial community and bacterial metabolites in jejunum of piglets. METHODS: Ten litters of newborn piglets ([Yorkshire×Landrace]×Duroc) were randomly divided into 2 groups of 5 litters. The piglets in the control group were suckled by the sow (SM), while the piglets in the treatment group (CM supplement) were supplemented with a CM supplement along with suckling from d 4 to d 28 of age. RESULTS: No significant differences were observed about jejunal mucosal morphology on d 28 and d 35 between two groups. On d 28, the activity of lactase in the jejunum was significantly decreased in the CM group, while the activity of sucrase and the ratio of maltase to lactase were significantly increased (p<0.05). On d 35, the activity of maltase in the jejunum was significantly increased in the CM group (p<0.05), and maltase to lactase ratio tended to increase in the CM group (p = 0.065). In addition, piglets in the CM group had a higher abundance of Clostridium XI, Tuicibater, and Moraxella in the jejunum on d 28, while the abundance of Lactobacillus was significantly increased on d 35 (p<0.05). CONCLUSION: The early CM supplement improved the maturation of the jejunum to some extent by enhancing the maltase and sucrase activities. Moreover, the early CM supplement could help maintain the homeostasis of internal environment in jejunum by increasing the microbial-derived metabolites.

The Changes of Colonic Bacterial Composition and Bacterial Metabolism Induced by an Early Food Introduction in a Neonatal Porcine Model.

The impact of an early food introduction on the microbiota composition and microbial metabolism in colon was investigated using a new-born piglet model. At day 4 after birth, 10 litters of piglets were randomly allocated to a sow-rearing group (SR group) and a milk-replacer supplementing group (MRS group) (n = 5). A commercial milk replacer was given to the suckling piglets in the MRS group from the 4th day to the 28th day. Pyrosequencing of the V3-V4 region of the 16S rRNA genes showed that the milk replacer supplementation significantly decreased the relative abundance of Lactobacillus, Clostridium XI, Blautia, Clostridium sensustricto and Escherichia (p = 0.08) in the colon of the piglets, but significantly increased the relative abundance of Paraprevotella on the 28th day. In addition, the abundance of Rumminococcus, Clostridium XlVa, Succiniclasticum, Clostridium IV tended to increase in the MRS group. The concentrations of acetate, propionate, butyrate, valerate and branch-chain fatty acids (BCFAs) in the colonic digesta increased with the milk replacer supplementary in the MRS group. In addition, the milk replacer supplementary increased the expression level of Toll-like receptor 4 (TLR4), but decreased the expression level of interleukin-6 (IL-6) in the colonic mucosa of the piglets. In conclusion, an early food introduction can influence the gut bacterial composition and metabolism, and may further affect the intestinal health by modifying the gene transcription related to the colonic function. These findings may provide some guidelines for the early nutrition supplementation for infants during the lactation period.

The long noncoding RNA urothelial carcinoma-associated 1 overexpression as a poor prognostic biomarker in clear cell renal cell carcinoma.

Long noncoding RNA urothelial carcinoma-associated 1 has previously played important roles in cancer. However, its role is still unknown in clear cell renal cell carcinoma. We utilized the most recent molecular and clinical data of clear cell renal cell carcinoma from The Cancer Genome Atlas project, and the relationship between urothelial carcinoma-associated 1 expression and the clinicopathological features was analyzed. Our results indicated that urothelial carcinoma-associated 1 overexpression was associated with male ( p = 0.003), wild-type PBRM1 ( p = 0.021), and BAP1 mutation ( p = 0.022) in clear cell renal cell carcinoma, although lower expression was found in tumors compared with normal controls, validated in tumor tissues from The Cancer Genome Atlas and 21 clear cell renal cell carcinoma patients at our hospital. Moreover, urothelial carcinoma-associated 1 overexpression indicated poor prognosis independently (Hazard Ratio [HR]: 1.92, p = 0.000) in clear cell renal cell carcinoma; it might be a potential detrimental gene considered as a predictive biomarker involved in clear cell renal cell carcinoma.

Investigating vertical distributions and photochemical indications of formaldehyde, glyoxal, and NO2 from MAX-DOAS observations in four typical cities of China.

Formaldehyde (HCHO), glyoxal (CHOCHO), and nitrogen dioxide (NO2) are crucial in atmospheric photochemical processes at both surface and elevated altitudes. This study presents synchronous multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements of the vertical distributions of summertime HCHO, CHOCHO and NO2 in four representative megacities within the Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), Sichuan Basin (SB), and Pearl River Delta (PRD) regions of China. The vertical distributions of HCHO and CHOCHO tended to occur at higher altitudes compared to NO2, influenced by both primary emissions near the ground and photochemical oxidation processes at elevated altitudes. Source separation regression analysis using the CO-CHOCHO trace pair identified secondary formation as the predominant source of ambient HCHO. In urban areas, the ratio of CHOCHO to secondary HCHO (RGFsec) serves as a more reliable metric at ground level for diagnosing VOC precursor sources, excluding the interference of primary and background HCHO. The increase in RGF values at higher altitudes highlights the relative contribution of VOCs favoring CHOCHO production. Moreover, four indicators (e.g. FNR, FNRsec, GNR, and MNR) were utilized to characterize O3 formation sensitivity at different altitudes. The range of FNR, FNRsec, GNR, and MNR marking the O3 formation sensitivity regime varies regionally, highlighting the need for localized assessments. The VOC-limited regime dominated at the ground level, whereas the contribution of the NOx-limited regime increased with altitude. Therefore, a comprehensive control strategy addressing both VOC and NOx emissions across different altitudes is essential for effectively mitigating photochemical pollution in urban areas of China.

TROPOMI unravels transboundary transport pathways of atmospheric carbon monoxide in Tibetan Plateau.

Numerous studies have reported in situ monitoring and source analysis in the Tibetan Plateau (TP), a region crucial for climate systems. However, a gap remains in understanding the comprehensive distribution of atmospheric pollutants in the TP and their transboundary pollution transport. Here, we analyzed the high-resolution satellite TROPOMI observations from 2018 to 2023 in Tibet and its surrounding areas. Our result reveals that, contrary to the results from in situ surface CO monitoring, Tibet exhibits a distinct seasonality in atmospheric carbon monoxide total column average mixing ratio (XCO), with higher levels in summer and lower levels in winter. This distinctive seasonal pattern may be related to the TP's 'air pump' effect and the Asia summer monsoon. Before 2022, the annual growth rate of XCO in Tibet was 1.63 %·year-1; however, it declined by 6.88 % in 2022. Source analysis and satellite observations suggest that CO from South Asia may enter Tibet either by crossing the Himalayas or through the Yarlung Zangbo Grand Canyon. We discovered that spring outbreaks of open biomass burning (OBB) in South and Southeast Asia led to an 11.57-27.98 % increase in XCO over Tibet. Favorable wind pattern and unique topography of the canyon promote the high concentrations CO transport to Tibet. Our greater concern is whether the TP will experience more severe transboundary pollution in the future.

Impact of elevated CO2 on microbial communities and functions in riparian sediments: Role of pollution levels in modulating effects.

The impact of elevated CO2 levels on microorganisms is a focal point in studying the environmental effects of global climate change. A growing number of studies have demonstrated the importance of the direct effects of elevated CO2 on microorganisms, which are confounded by indirect effects that are not easily identified. Riparian zones have become key factor in identifying the environmental effects of global climate change because of their special location. However, the direct effects of elevated CO2 levels on microbial activity and function in riparian zone sediments remain unclear. In this study, three riparian sediments with different pollution risk levels of heavy metals and nutrients were selected to explore the direct response of microbial communities and functions to elevated CO2 excluding plants. The results showed that the short-term effects of elevated CO2 did not change the diversity of the bacterial and fungal communities, but altered the composition of their communities. Additionally, differences were observed in the responses of microbial functions to elevated CO2 levels among the three regions. Elevated CO2 promoted the activities of nitrification and denitrification enzymes and led to significant increases in N2O release in the three sediments, with the greatest increase of 76.09 % observed in the Yuyangshan Bay (YYS). Microbial carbon metabolism was promoted by elevated CO2 in YYS but was significantly inhibited by elevated CO2 in Gonghu Bay and Meiliang Bay. Moreover, TOC, TN, and Pb contents were identified as key factors contributing to the different microbial responses to elevated CO2 in sediments with different heavy metal and nutrient pollution. In conclusion, this study provides in-depth insights into the responses of bacteria and fungi in polluted riparian sediments to elevated CO2, which helps elucidate the complex interactions between microbial activity and environmental stressors.

Surface Energy-Assisted Patterning of Vapor Deposited All-Inorganic Perovskite Arrays for Wearable Optoelectronics.

Solution-based methods for fabricating all-inorganic perovskite film arrays often suffer from limited control over nucleation and crystallization, resulting in poor homogeneity and coverage. To improve film quality, advanced vapor deposition techniques are employed for continuous film. Here, the vapor deposition strategy to the all-inorganic perovskite films array, enabling area-selective deposition of perovskite through substrate modulation is expanded. It can yield a high-quality perovskite film array with different pixel shapes, various perovskite compositions, and a high resolution of 423 dpi. The resulting photodetector arrays exhibit remarkable optoelectronic performance with an on/off ratio of 13 887 and responsivity of 47.5 A W-1. The device also displays long-term stability in a damp condition for up to 12 h. Moreover, a pulse monitoring sensor based on the perovskite films array demonstrates stable monitoring for pulse signals after being worn for 12 h and with a low illumination of 0.055 mW cm-2, highlighting the potential application in wearable optoelectronic devices.

Evaluating the performance of carbon dioxide and methane observations from carbon-monitoring satellite products over China.

As the primary greenhouse gases contributing to climate change, carbon dioxide (CO2) and methane (CH4) play a critical role in the Earth's radiative balance and temperature regulation. Continuous and accurate satellite monitoring of CO2 and CH4 is essential for developing effective policies and strategies to mitigate their impacts. This study utilizes ground-based Fourier-transform infrared measurements from the Total Carbon Column Observing Network (TCCON) to evaluate the performance of current mainstream carbon-monitoring satellites over China, the world's largest carbon emitter. Our findings show that TanSat performs excellently for CO2 observations at both Hefei and Xianghe sites, achieving a standard deviation (SD) of about 2 ppm and a maximum bias of 0.25 ppm, dropping to 0.02 ppm at Xianghe. In contrast, Orbiting Carbon Observatory (OCO)-3 and Greenhouse Gases Observing Satellite (GOSAT)-2 CO2 measurements are slightly less reliable. For CH4 monitoring, GOSAT outperforms GOSAT-2, with a SD of around 14 ppb and bias within 2 ppb, compared to GOSAT-2's 17.58 ppb SD and 2.15 ppb bias at Hefei. These results indicate that the latest carbon-monitoring satellites are less precise and accurate than their predecessors. Additionally, we provide detailed assessments of the data products based on different spatial matching criteria. We also discuss the variation in satellite accuracy over time, revealing periodic bias variations and the instability in satellite performance. Furthermore, while the spatial distribution trends of satellite acquisitions are generally consistent on an annual scale, we observe non-negligible differences in the annual averages across specific land surfaces. Our study presents a meticulous evaluation of the reliability of satellite-based carbon-monitoring products over the Chinese region and provides scientific evidence for analyzing uncertainty in carbon source-sink studies.

Quantification and evaluation of atmospheric emissions from crop residue burning constrained by satellite observations in China during 2016-2020.

In rural regions of China, crop residue burning (CRB) is the major biomass burning activity, which can result in massive emissions of atmospheric particulate, greenhouse gas, and trace gas pollutants. Based on Himawari-8 satellite fire radiative power and agricultural statistics data, we implemented a daily inventory of agricultural fire emissions in 2016-2020 with a 2-km spatial resolution, including atmospheric pollutants such as CO2, CH4, CO, N2O, NOX, NH3, SO2, PM10, PM2.5, Hg, OC, EC, and NMVOCs. Our inventory constrained by geostationary satellite monitoring is more consistent with the actual CRB emissions in China, as many flaring events occur surreptitiously in the early morning and late evening to avoid regulation, which may be overlooked by polar-orbiting satellites. The spatiotemporal characterizations of various CRB emissions are found to be consistent with multiple satellite trace gas retrievals. We also assessed the effectiveness of field burning bans in China. Combined with other relevant datasets, it was found that although China has been advocating for a long time not to burn straw in the open field, CRB emissions was not successfully controlled nationwide until 2016. We estimated that the cumulative reduction of CO2 CRB emissions alone amounts to 809 ± 651 (2σ) teragram (Tg) during the 13th Five-Year Plan period (2016-2020), with an average value equivalent to 1.2 times the total annual territorial CO2 emissions by fossil fuels from Germany in 2021 (675 Tg, ranked 1st in EU27 and 7th in the world). Our inventory also suggests that continuous, long-term controls are necessary. Otherwise, CRB emissions may only be delayed on a seasonal scale, rather than reduced.

Vast ecosystem disturbance in a warming climate may jeopardize our climate goal of reducing CO2: a case study for megafires in the Australian 'black summer'.

A warming climate is one of the most important driving forces of intensified wildfires globally. The unprecedented wildfires broke out in the Australian 'Black Summer' (November 2019-February 2020), which released massive heat, gases, and particles into the atmosphere. The total carbon dioxide (CO2) emissions from wildfires were estimated at ∼963 million tons by using a top-down approach based on direct satellite measurements of CO2 and fire radiative power. The fire emissions have led to an approximately 50-80 folds increase in total CO2 emission in Australia compared with the similar seasons of 2014-2019. The excess CO2 from wildfires has offset almost half of the global anthropogenic CO2 emission reductions due to the Corona Virus Disease 2019 in 2020. When the wildfires were intense in December 2019, they caused a 1.48 watts per square meter additional positive radiative forcing above the monthly average in Australia and the vicinity. Our findings demonstrate that vast ecosystem disturbance in a warming climate can strongly influence the global carbon cycle and hamper our climate goal of reducing CO2.

A Universal Fabrication Strategy for High-Resolution Perovskite-Based Photodetector Arrays.

Metal halide perovskite photodetector arrays have demonstrated great potential applications in the field of integrated systems, optical communications, and health monitoring. However, the fabrication of large-scale and high-resolution device is still challenging due to their incompatibility with the polar solvents. Here, a universal fabrication strategy that utilizes ultrathin encapsulation-assisted photolithography and etching to create high-resolution photodetectors array with vertical crossbar structure is reported. This approach yields a 48 × 48 photodetector array with a resolution of 317 ppi. The device shows good imaging capability with a high on/off ratio of 3.3 × 105 and long-term working stability over 12 h. Furthermore, this strategy can be applied to five different material systems, and is fully compatible with the existing photolithography and etching techniques, which are expected to have potential applications in the other high-density and solvent-sensitive devices array, including perovskite- or organic semiconductor-based memristor, light emitting diode displays, and transistors.

Atomic-level chemical reaction promoting external quantum efficiency of organic photomultiplication photodetector exceeding 108% for weak-light detection.

Low-cost, solution-processed photomultiplication organic photodetectors (PM-OPDs) with external quantum efficiency (EQE) above unity have attracted enormous attention. However, their weak-light detection is unpleasant because the anode Ohmic contact causes exacerbation in dark current. Here, we introduce atomic-level chemical reaction in PM-OPDs which can simultaneously suppress dark current and increase EQE via depositing a 0.8 nm thick Al2O3 by the atomic layer deposition. Suppression in dark current mainly originates from the built-in anode Schottky junction as a result of work function decrease of hole-transporting layer of which the chemical groups can react chemically with the bottom surface of Al2O3 layer at the atomic-level. Such strategy of suppressing dark current is not adverse to charge injection under illumination; instead, responsivity enhancement is realized because charge injection can shift from cathode to anode, of which the neighborhood possesses increased photogenerated carriers. Consequently, weak-light detection limit of the forwardly-biased PM-OPD with Al2O3 treatment reaches a remarkable level of 2.5 nW cm-2, while that of the reversely-biased control is 25 times inferior. Meanwhile, the PM-OPD yields a record high EQE and responsivity of 4.31 × 108% and 1.85 × 106 A W-1, respectively, outperforming all other polymer-based PM-OPDs.