Ultrahigh Gain Solar Blind Avalanche Photodetector Using an Amorphous Ga2O3-Based Heterojunction

Solar blind photodetectors with a cutoff wavelength within the 200-280 nm region is attracting much attention due to their potential civilian and military applications. The avalanche photodetectors (APDs) formed based on wide-bandgap semiconductor Ga₂O₃ are expected to meet emerging technological demands. These devices, however, suffer from limitations associated with the quality of as-grown Ga₂O₃ or the difficulty in alleviating the defects and dislocations. Herein, high-performance APDs incorporating amorphous Ga₂O₃ (a-Ga₂O₃)/ITO heterojunction as the central element have been reliably fabricated at room temperature. The a-Ga₂O₃-based APDs exhibits an ultrahigh responsivity of 5.9 × 10⁴ A/W, specific detectivity of 1.8 × 10¹⁴ Jones, and an external quantum efficiency up to 2.9 × 10⁷% under 254 nm light irradiation at 40 V reverse bias. Notably, the gain could reach 6.8 × 10⁴, indicating the outstanding capability for ultraweak signals detection. The comprehensive superior capabilities of the a-Ga₂O₃-based APDs can be ascribed to the intrinsic carrier transport manners in a-Ga₂O₃ as well as the modified band alignment at the heterojunctions. The trade-off between low processing temperature and superior characteristics of a-Ga₂O₃ promises greater design freedom for realization of wide applications of emerging semiconductor Ga₂O₃ with even better performance since relieving the burden on the integration progress.

Search for a Higgs Portal Scalar Decaying to Electron-Positron Pairs in the MicroBooNE Detector

We present a search for the decays of a neutral scalar boson produced by kaons decaying at rest, in the context of the Higgs portal model, using the MicroBooNE detector. We analyze data triggered in time with the Fermilab NuMI neutrino beam spill, with an exposure of 1.93×10^{20} protons on target. We look for monoenergetic scalars that come from the direction of the NuMI hadron absorber, at a distance of 100 m from the detector, and decay to electron-positron pairs. We observe one candidate event, with a standard model background prediction of 1.9±0.8. We set an upper limit on the scalar-Higgs mixing angle of θ<(3.3-4.6)×10^{-4} at the 95% confidence level for scalar boson masses in the range (100-200)  MeV/c^{2}. We exclude, at the 95% confidence level, the remaining model parameters required to explain the central value of a possible excess of K_{L}^{0}→π^{0}νν[over ¯] decays reported by the KOTO collaboration. We also provide a model-independent limit on a new boson X produced in K→πX decays and decaying to e^{+}e^{-}.

Emerging polymer electrodes for aqueous energy storage

New generation energy storage devices call for electrodes with high capacity, high cycling performance and environmental benignity. Polymer electrode materials (PEMs) are attractive for their abundant structural diversity and tunability as well as engineered conductivity, desirable processability and electrochemical properties for aqueous batteries. We herein overview the state-of-the-art development of PEMs for aqueous batteries, including conventional doped, redox-backbone, redox-pendant and hydrophilic conducting polymers. The merits and demerits of PEMs, and their structural modification and energy storage performance are discussed in detail. To provide a comprehensive understanding of polymer-based aqueous batteries, we correlate the molecular structures of PEMs with their conductivity, morphology and electrochemical behaviors. The review offers an insight into the rational design of conducting polymer electrodes for safe and cost-effective aqueous batteries.

Cosmic Ray Background Removal With Deep Neural Networks in SBND

In liquid argon time projection chambers exposed to neutrino beams and running on or near surface levels, cosmic muons, and other cosmic particles are incident on the detectors while a single neutrino-induced event is being recorded. In practice, this means that data from surface liquid argon time projection chambers will be dominated by cosmic particles, both as a source of event triggers and as the majority of the particle count in true neutrino-triggered events. In this work, we demonstrate a novel application of deep learning techniques to remove these background particles by applying deep learning on full detector images from the SBND detector, the near detector in the Fermilab Short-Baseline Neutrino Program. We use this technique to identify, on a pixel-by-pixel level, whether recorded activity originated from cosmic particles or neutrino interactions.

Conventional transarterial chemoembolization combined with systemic therapy versus systemic therapy alone as second-line treatment for unresectable colorectal liver metastases: randomized clinical trial

BACKGROUND

The combination of conventional transarterial chemoembolization (cTACE) and systemic therapy has the potential to treat chemotherapy-refractory unresectable colorectal liver metastases (CRLMs). This study aimed to compare survival after this combined treatment versus systemic chemotherapy alone.

METHODS

This single-centre RCT included patients with unresectable CRLMs that progressed after first-line treatment. Patients were randomized on a 1 : 1 basis to either systemic chemotherapy with or without cTACE, without further stratification. The primary outcome was progression-free survival (PFS). Secondary outcomes were overall response rate, disease control rate, conversion rate to liver resection, overall survival, and adverse events.

RESULTS

Of 180 patients recruited, 168 were randomized. Eighty-five patients in arm A received systemic chemotherapy plus cTACE and 83 in arm B received systemic chemotherapy alone. Median PFS was longer in arm A than B (6.7 versus 3.8 months; hazard ratio (HR) 0.67, 95 per cent c.i. 0.49 to 0.91; P = 0.009), but did not translate into prolonged median overall survival (18.4 versus 14.8 months; HR = 0.92, 0.62 to 1.36; P = 0.669). Overall response rates (20 versus 22 per cent; P = 0.788) and conversion rate to liver resection (18 versus 16 per cent; P = 0.730) were no different between arms A and B. The disease control rate was higher in arm A than arm B (67 versus 51 per cent; P = 0.030). No adverse event higher than grade 3 according to the Common Terminology Criteria for Adverse Events was observed during treatment.

CONCLUSION

Systemic chemotherapy plus cTACE is a safe option as second-line treatment for unresectable colorectal liver metastases, with a modest effect on PFS. Registration number: NCT03783559 (http://www.clinicaltrials.gov).

Characterization of a carboxyl methyltransferase in Fusarium graminearum provides insights into the biosynthesis of fusarin A

Fusarium graminearum is a major fungal pathogen that causes a series of devastating crop diseases by producing a variety of mycotoxins. Fusarins are a class of polyketide-nonribosomal peptide hybrids. In Fusarium mycotoxins, a variable 2-pyrrolidone ring conjugates with a polyene chain substituted with a methyl ester moiety. The enzymatic route through which fusarin A, a major member of the fusarin family with a characteristic tetrohydrofuran-coupled pyrrolidone ring, is formed in F. graminearum has not been established. By targeting the final step in the biosynthesis of fusarin A, we report here an S-adenosyl methionine-dependent carboxyl methyltransferase responsible for the formation of the methyl ester moiety by in vivo gene inactivation, isolation and characterization of a key fusarin intermediate, and in vitro biochemical characterization. Related findings provide insights into the poorly understood biosynthetic pathway of fusarin A. Additionally, bioactivity assays demonstrate that the methyl ester is necessary for fusarin cytotoxicity.

Correction: Characterization of a carboxyl methyltransferase in Fusarium graminearum provides insights into the biosynthesis of fusarin A

Correction for 'Characterization of a carboxyl methyltransferase in Fusarium graminearum provides insights into the biosynthesis of fusarin A' by Qian Yang et al., Org. Biomol. Chem., 2021, DOI: 10.1039/d1ob01010g.

Sodium Danshensu inhibits the progression of lung cancer by regulating PI3K/Akt signaling pathway

Sodium Danshensu, extracted from the root of the Salvia miltiorrhiza, has pleiotropic effects including anti-oxidation, anti-inflammation and anti-tumor. However, whether Sodium Danshensu has an anti-cancer effect in lung cancer remains to be elucidated. The present study aimed to illustrate the effects of Sodium Danshensu on lung cancer cells and the potential molecular mechanisms. BEAS-2B, A549, and NCI-H1299 cells were stimulated with 25, 50, and 100 μM Sodium Danshensu for 24, 48, and 72 h, and then cell viability, apoptosis, migration and invasion were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry and Transwell assays, respectively. Moreover, the levels of Proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 9 (MMP9), B-cell lymphoma-2 (Bcl-2) associated X (Bax), Bcl-2, phosphorylated (p)-phosphoinositide 3-kinase (PI3K), and p-Protein kinase B (AKT) in lung cancer cells were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) and/or Western blot assays. We observed that Sodium Danshensu suppressed cells viability, migration, and invasion, as well as promoted cells apoptosis in A549 and NCI-H1299 cells in a dose-dependent manner, while Sodium Danshensu had no cytotoxic effect on the proliferation activity of BEAS-2B cells. Moreover, the expression of PCNA, MMP9, Bcl-2 were decreased, but Bax was up-regulated in Sodium Danshensu-treated A549 and NCI-H1299 cells. Our findings also revealed that Sodium Danshensu inhibited PI3K/AKT pathway in A549 and NCI-H1299 cells. In conclusion, our study provided the first evidence that Sodium Danshensu suppressed the malignant biological behaviors of lung cancer cells, indicating that Sodium Danshensu might be a latent candidate for lung cancer therapy.

A Simple Dithieno[3,2-b:2',3'-d]pyrrol-Rhodanine Molecular Third Component Enables Over 16.7% Efficiency and Stable Organic Solar Cells

Organic solar cells (OSCs) can achieve greatly improved power conversion efficiency (PCE) by incorporating suitable additives in active layers. Their structure design often faces the challenge of operation generality for more binary blends. Herein, a simple dithieno[3,2-b:2',3'-d]pyrrole-rhodanine molecule (DR8) featuring high compatibility with polymer donor PM6 is developed as a cost-effective third component. By employing classic ITIC-like ITC6-4Cl and Y6 as model nonfullerene acceptors (NFAs) in PM6-based binary blends, DR8 added PM6:ITC6-4Cl blends exhibit significantly promoted energy transfer and exciton dissociation. The PM6:ITC6-4Cl:DR8 (1:1:0.1, weight ratio) OSCs contribute an exciting PCE of 14.94% in comparison to host binary devices (13.52%), while PM6:Y6:DR8 (1:1.2:0.1) blends enable 16.73% PCE with all simultaneously improved photovoltaic parameters. To the best of the knowledge, this performance is among the best for ternary OSCs with simple small molecular third components in the literature. More importantly, DR8-added ternary OSCs exhibit much improved device stability against thermal aging and light soaking over binary ones. This work provides new insight on the design of efficient third components for OSCs.

System-on-chip upgrade of millimeter-wave imaging diagnostics for fusion plasma

Monolithic, millimeter wave "system-on-chip" technology has been employed in chip heterodyne radiometers in a newly developed Electron Cyclotron Emission Imaging (ECEI) system on the DIII-D tokamak for 2D electron temperature and fluctuation diagnostics. The system employs 20 horn-waveguide receiver modules each with customized W-band (75-110 GHz) monolithic microwave integrated circuit chips comprising a W-band low noise amplifier, a balanced mixer, a ×2 local oscillator (LO) frequency doubler, and two intermediate frequency amplifier stages in each module. Compared to previous quasi-optical ECEI arrays with Schottky mixer diodes mounted on planar antennas, the upgraded W-band array exhibits >30 dB additional gain and 20× improvement in noise temperature; an internal eight times multiplier chain is used to provide LO coupling, thereby eliminating the need for quasi-optical coupling. The horn-waveguide shielding housing avoids out-of-band noise interference on each module. The upgraded ECEI system plays an important role for absolute electron temperature and fluctuation measurements for edge and core region transport physics studies. An F-band receiver chip (up to 140 GHz) is under development for additional fusion facilities with a higher toroidal magnetic field. Visualization diagnostics provide multi-scale and multi-dimensional data in plasma profile evolution. A significant aspect of imaging measurement is focusing on artificial intelligence for science applications.

A plasma membrane transporter coordinates phosphate reallocation and grain filling in cereals

Phosphate (Pi) is essential to plant growth and crop yield. However, it remains unknown how Pi homeostasis is maintained during cereal grain filling. Here, we identified a rice grain-filling-controlling PHO1-type Pi transporter, OsPHO1;2, through map-based cloning. Pi efflux activity and its localization to the plasma membrane of seed tissues implicated a specific role for OsPHO1;2 in Pi reallocation during grain filling. Indeed, Pi over-accumulated in developing seeds of the Ospho1;2 mutant, which inhibited the activity of ADP-glucose pyrophosphorylase (AGPase), important for starch synthesis, and the grain-filling defect was alleviated by overexpression of AGPase in Ospho1;2-mutant plants. A conserved function was recognized for the maize transporter ZmPHO1;2. Importantly, ectopic overexpression of OsPHO1;2 enhanced grain yield, especially under low-Pi conditions. Collectively, we discovered a mechanism underlying Pi transport, grain filling and P-use efficiency, providing an efficient strategy for improving grain yield with minimal P-fertilizer input in cereals.

Carbonyl-enriched hierarchical carbon synergizes redox electrolyte for highly-efficient and stable supercapacitors

Carbonyl-functionalized carbon porous leaves modifying carbon channels have been reported via single-step wood carbonization. A redox reaction between carbonyl and cupric chloride endows the freestanding electrode with an ultrahigh area specific capacitance of 13.1 F cm^-2 (30 mA cm^-2) and over 99.6% retention after 45 000 cycles in supercapacitors.

Electrical Characterizations of Planar Ga2O3 Schottky Barrier Diodes

In this work, a Schottky barrier diode (SBD) is fabricated and demonstrated based on the edge-defined film-fed grown (EFG) Ga₂O₃ crystal substrate. At the current stage, for high resistance un-doped Ga₂O₃ films and/or bulk substrates, the carrier concentration (and other electrical parameters) is difficult to be obtained by using the conventional Hall measurement. Therefore, we extracted the electrical parameters such as on-state resistance (R_on), Schottky barrier height (ϕB), the ideal factor (n), series resistance (R_s) and the carrier concentration (N_d) by analyzing the current density–voltage (J–V) and capacitance–voltage (C–V) curves of the Ga₂O₃-based SBD, systematically. The detailed measurements and theoretical analysis are displayed in this paper.

A novel homozygous mutation (p.N958K) of SLC12A3 in Gitelman syndrome is associated with endoplasmic reticulum stress

PURPOSE

Gitelman syndrome (GS) is an autosomal recessive renal tubular disease that arises as a consequence of mutations in the SLC12A3 gene, which codes for an Na-Cl cotransporter (NCC) in distal renal tubules. This study was designed to explore the mutations associated with GS in an effort to more fully understand the molecular mechanisms governing GS.

METHODS

We analyzed SLC12A3 mutations in a pedigree including a 42-year-old male with GS as well as four related family members over three generations using Sanger and next generation sequencing approaches. We additionally explored the functional ramifications of identified mutations using both Xenopus oocytes and the HEK293T cell line.

RESULTS

We found that the subject with GS exhibited characteristic symptoms including sporadic thirst, fatigue, excess urination, and substantial hypokalemia and hypocalciuria, although magnesium levels were normal. Other analyzed subjects in this pedigree had normal laboratory findings and did not exhibit clear signs of GS. Sequencing analyses revealed that the GS subject exhibited a homozygous missense mutation (c.2874C > G, p.N958K) in exon 24 of SLC12A3. Both parents of this GS subject, as well as his older brother and daughter all exhibited heterozygous mutations at this same site. Functional analyses in Xenopus oocytes indicated that this mutated SLC12A3 gene encodes a protein which fails to mediate normal sodium transport, and when this mutant gene was expressed in HEK293T cells, we observed significant increases in endoplasmic reticulum (ER)-stress pathway activation.

CONCLUSION

The p.N958K mutation in exon 24 of SLC12A3 can trigger GS at least in part via enhancing ER stress responses.

An unfused-ring acceptor with high side-chain economy enabling 11.17% as-cast organic solar cells

Side-chain engineering on nonfullerene acceptors (NFAs) is crucial for modulating their solubility and crystallinity as well as packing behaviours in active layers to pursue high-performance organic solar cells (OSCs). High weight ratios of side chains are generally used by NFAs for the desired device efficiencies. Side-chain economy has seldom been discussed despite increased cost and difficulties in synthesis when optimizing the molecular design. Herein, we introduce 7H-dibenzo[c,g]carbazole (DCB) as an electron-donating core to design unfused-ring acceptors (UFAs) with a dramatically low weight ratio of side chains. DCB-4F has thus been designed and compared with the carbazole cored analogue (CB-4F). The unique conformation of the DCB core endows DCB-4F with higher solubility (8.2 mg mL^-1 in chloroform) compared to CB-4F (2.2 mg mL^-1) when using the same side chains. Featuring a lowest unoccupied molecular orbital (LUMO) level of -3.86 eV and an optical bandgap of 1.55 eV, the DCB-4F film exhibits an absorption profile (maximum 667 nm) complementary to polymer donor PM6. The PM6:DCB-4F as-cast OSCs deliver a power conversion efficiency (PCE) of 9.56% with a high open-circuit voltage (V_OC) of 1.00 V. By adding 10 wt% PC₇₁BM into the casting solutions, a greatly improved PCE of 11.17% is readily achieved, which is one of the highest PCEs for as-cast single-junction UFA-based devices. The PM6:DCB-4F based blends show homogeneous nano-fiberous morphology and higher hydrophobicity. The design of conformation-tuned NFAs using sterically hindered DCB-like cores is promising to achieve highly efficient as-cast OSCs.