Manipulating Surface Band Bending of III-Nitride Nanowires with Ambipolar Charge-Transfer Characteristics: A Pathway Toward Advanced Photoswitching Logic Gates and Encrypted Optical Communication.

The operational principle of semiconductor devices critically relies on the band structures that ultimately govern their charge-transfer characteristics. Indeed, the precise orchestration of band structure within semiconductor devices, notably at the semiconductor surface and corresponding interface, continues to pose a perennial conundrum. Herein, for the first time, this work reports a novel postepitaxy method: thickness-tunable carbon layer decoration to continuously manipulate the surface band bending of III-nitride semiconductors. Specifically, the surface band bending of p-type aluminum-gallium-nitride (p-AlGaN) nanowires grown on n-Si can be precisely controlled by depositing different carbon layers as guided by theoretical calculations, which eventually regulate the ambipolar charge-transfer behavior between the p-AlGaN/electrolyte and p-AlGaN/n-Si interface in an electrolyte environment. Enabled by the accurate modulation of the thickness of carbon layers, a spectrally distinctive bipolar photoresponse with a controllable polarity-switching-point over a wide spectrum range can be achieved, further demonstrating reprogrammable photoswitching logic gates "XOR", "NAND", "OR", and "NOT" in a single device. Finally, this work constructs a secured image transmission system where the optical signals are encrypted through the "XOR" logic operations. The proposed continuous surface band tuning strategy provides an effective avenue for the development of multifunctional integrated-photonics systems implemented with nanophotonics.

Lycium barbarum glycopeptide targets PER2 to inhibit lipogenesis in glioblastoma by downregulating SREBP1c.

Lycium barbarum polysaccharide (LBP) is a substance with various biological activities extracted from Lycium barbarum. LbGPs are peptidoglycans with a short peptide backbone and a complex, branched glycan moiety, which is further extracted and isolated from LBPs. Previous studies have shown that LbGP can inhibit cancer cell growth, but its specific mechanism is not completely clear. In this study, we found that LbGP could inhibit the proliferation of glioma cells and promote the expression of period 2 (PER2) through the PKA-CREB pathway. In addition, LbGP could inhibit the de novo synthesis of lipids by downregulating SREBP1c and its target genes, which depended on the expression of PER2. Moreover, PER2 negatively regulated the expression of SREBP1c via suppressing PI3K/AKT/mTOR pathway. In summary, LbGP may upregulate the expression of PER2 to reduce the expression of SREBP1c, inhibit lipid synthesis in glioblastoma, and inhibit glioblastoma cell proliferation. This study provides an alternative drug for the treatment of glioma and elucidates its potential mechanism.

Achieving Record-High Photoelectrochemical Photoresponse Characteristics by Employing Co3O4 Nanoclusters as Hole Charging Layer for Underwater Optical Communication.

The physicochemical properties of a semiconductor surface, especially in low-dimensional nanostructures, determine the electrical and optical behavior of the devices. Thereby, the precise control of surface properties is a prerequisite for not only preserving the intrinsic material quality but also manipulating carrier transport behavior for promoting device characteristics. Here, we report a facile approach to suppress the photocorrosion effect while boosting the photoresponse performance of n-GaN nanowires in a constructed photoelectrochemical-type photodetector by employing Co3O4 nanoclusters as a hole charging layer. Essentially, the Co3O4 nanoclusters not only alleviate nanowires from corrosion by optimizing the oxygen evolution reaction kinetics at the nanowire/electrolyte interface but also facilitate an efficient photogenerated carrier separation, migration, and collection process, leading to a significant ease of photocurrent attenuation (improved by nearly 867% after Co3O4 decoration). Strikingly, a record-high responsivity of 217.2 mA W-1 with an ultrafast response/recovery time of 0.03/0.02 ms can also be achieved, demonstrating one of the best performances among the reported photoelectrochemical-type photodetectors, that ultimately allowed us to build an underwater optical communication system based on the proposed nanowire array for practical applications. This work provides a perspective for the rational design of stable nanostructures for various applications in photo- and biosensing or energy-harvesting nanosystems.

Anisotropic photoresponse behavior of a LaAlO3 single-crystal-based vacuum-ultraviolet photodetector.

Nowadays, vacuum-ultraviolet (VUV) photodetectors (PDs) have attracted extensive attention owing to their potential applications in space exploration, radiation monitoring, and the semiconductor industry. Benefiting from its intrinsic ultra-wide band-gap, chemical robustness, and low-cost features, LaAlO3 shows great promise in developing next-generation compact, cheap, and easy-to-fabricate VUV PDs. In this work, we report the unique anisotropic photoresponse behavior of LaAlO3 single crystals for VUV photodetection applications. First of all, with the guidance of density functional theory (DFT) calculations along with the comprehensive material characterization, the anisotropic carrier transport behavior of LaAlO3 single crystals was confirmed. Thereafter, after exploring the metal-semiconductor-metal (MSM) device configuration along different substrate orientations, including (100), (110), and (111)-LaAlO3 single crystals, we found that the (110)-LaAlO3 VUV PD exhibits the best device performance under VUV illumination, with a responsivity of 2.23 mA W-1, a high detectivity of 3.72 × 1011 Jones, and a photo-to-dark-current ratio of 5.48 × 103. This work not only provides a feasible avenue to explore the anisotropic optoelectronic behavior of ultra-wide band-gap semiconductors but also expands the application of the low-cost oxide perovskite family in the field of VUV photodetection.

Intraluminal Diverticular Duodenal Duplication With Recurrent Abdominal Pain: A Case Report.

Duodenal duplication is a rare congenital anomaly and may manifest as pancreatitis, gastrointestinal bleeding, abdominal pain, perforation, and obstruction. Here, we present a case of intraluminal diverticular duodenal duplication (IDDD) in a child with recurrent abdominal pain caused by a large hole-like structure in the duodenal bulb. This condition has rarely been reported. An 11-year-old boy presented with recurrent attacks of abdominal pain. Upper endoscopy examination and barium swallowing led to an initial diagnosis of IDDD; this diagnosis was confirmed by operative findings and histopathological signs. He underwent a subtotal excision and duodenal anastomosis. No serious complications occurred following treatment. The patient was followed up for 8 months, and his condition improved without symptoms.

Is percutaneous access superior to cutdown access for endovascular abdominal aortic aneurysm repair? A meta-analysis.

OBJECTIVE: The objective is to investigate whether percutaneous access (pEVAR) is superior to cutdown access (cEVAR) in terms of safety and efficacy during endovascular repair of abdominal aortic aneurysms (AAAs). METHODS: We searched PubMed, Embase, and Cochrane Library from January 1999 to December 2020 for studies reporting on the comparison between percutaneous and cutdown techniques for endovascular repair of AAAs. Outcomes evaluated were technical success rates, access site-related complications and operative time, and hospital stay. RESULTS: Four randomized controlled trials and nine observational studies with a total of 1683 patients comprising 2715 groin accesses were eligible for the meta-analysis. pEVAR was associated with a lower risk of overall complications (odds ratio (OR) = 0.63; p = .005) and seroma/lymphorrhea (OR, 0.18; p = .0001) and shortened operation time (MD = -39.04; p = .002) and the length of hospital stay (MD = -0.75; p < .00001) compared with cEVAR. The technical success rate for pEVAR was 95.1% (694/729), with an overall OR of 0.27 (95% CI 0.14-0.55, p = .0003) comparing pEVAR with cEVAR. Furthermore, pEVAR did not increase the risk of site infection, femoral artery thrombosis, postoperative hematoma, nerve injury, dissection, and bleeding. CONCLUSION: Percutaneous endovascular aneurysm repair is a safe and effective method for the treatment of AAA. It reduces the risk of overall complications and shortens the operation time and hospital stay. The technical success rate of pEVAR is lower than that of cEVAR, which may be linked to the selection of patients, operator experience, and the use of ultrasound. Large definitive trials are required to draw robust conclusions.

Endovascular Repair of an Aneurysm Arising from a Celiomesenteric Trunk.

Celiac axis (CA) aneurysm is a rare vascular condition, consisting of only 3.6-4% of visceral artery aneurysms but is frequently life threatening and can result in death. A celiomesenteric trunk (CMT) is an anatomic anomaly in which the celiac and superior mesenteric arteries arise from a common trunk. This structure accounts for only 1% of visceral artery variation, and a celiac artery aneurysm at a CMT is exceptionally rare. Here, we report the case of a 62-year-old woman with a celiac artery aneurysm at a CMT. Endovascular repair was completed using a bare metal stent-assisted coil. Satisfactory results were observed at the 10-month follow-up. To our knowledge, this is the first case reported of bare metal stent-assisted coil repair of a CA aneurysm at a CMT.

Multiple domains of bacterial and human Lon proteases define substrate selectivity.

The Lon protease selectively degrades abnormal proteins or certain normal proteins in response to environmental and cellular conditions in many prokaryotic and eukaryotic organisms. However, the mechanism(s) behind the substrate selection of normal proteins remains largely unknown. In this study, we identified 10 new substrates of F. tularensis Lon from a total of 21 candidate substrates identified in our previous work, the largest number of novel Lon substrates from a single study. Cross-species degradation of these and other known Lon substrates revealed that human Lon is unable to degrade many bacterial Lon substrates, suggestive of a "organism-adapted" substrate selection mechanism for the natural Lon variants. However, individually replacing the N, A, and P domains of human Lon with the counterparts of bacterial Lon did not enable the human protease to degrade the same bacterial Lon substrates. This result showed that the "organism-adapted" substrate selection depends on multiple domains of the Lon proteases. Further in vitro proteolysis and mass spectrometry analysis revealed a similar substrate cleavage pattern between the bacterial and human Lon variants, which was exemplified by predominant representation of leucine, alanine, and other hydrophobic amino acids at the P(-1) site within the substrates. These observations suggest that the Lon proteases select their substrates at least in part by fine structural matching with the proteins in the same organisms.