Interface engineering and passivating contacts are key enablers to reach the highest efficiencies in photovoltaic devices. While printed carbon–graphite back electrodes for hole‐transporting material ...(HTM)‐free perovskite solar cells (PSCs) are appealing for fast commercialization of PSCs due to low processing costs and extraordinary stability, this device architecture so far suffers from severe performance losses at the back electrode interface. Herein, a 2D perovskite passivation layer as an electron blocking layer (EBL) at this interface to substantially reduce interfacial recombination losses is introduced. The formation of the 2D perovskite EBL is confirmed through X‐ray diffraction, photoemission spectroscopy, and an advanced spectrally resolved photoluminescence microscopy mapping technique. Reduced losses that lead to an enhanced fill factor and VOC are quantified by electrochemical impedance spectroscopy and JSC–VOC measurements. This enables reaching one of the highest reported efficiencies of 18.5% for HTM‐free PSCs using 2D perovskite as an EBL with a significantly improved device stability.
A 2D perovskite passivation layer is introduced as an electron blocking layer at the 3D perovskite/carbon interface in hole transporting layer (HTL) free carbon electrode‐based perovskite solar cells. The substantial reduction of recombination losses due to the electron‐blocking 2D perovskite results in a high power conversion efficiency for HTL‐free devices (18.5%) with an improved stability.
A 30.1-dBm quadrature transmitter is implemented based on Class-G IQ-cell-shared switched-capacitor power amplifier (SCPA) and voltage mismatch compensation techniques for dual-supply voltage in a ...Class-G SCPA. For the Class-G operation in the IQ-cell-shared quadrature SCPA, a merged cell switching (MCS) technique comprising vector amplitude switching (VAS) and vector phase switching (VPS) is proposed. The VAS boosts system efficiency (SE) by enabling the Class-G operation with multiple supply voltages and the VPS conserves vector information in the merged cells that process the quadrature vectors. The linearization technique for Class-G SCPA minimizes the distortion that arises from the supply-voltage mismatches in a multiple supply-voltage system. Two SCPAs are coupled with a power combining transformer to achieve a watt-level output power. A time-domain interpolation minimizes the spectral image. The prototype SCPA, fabricated in a 65-nm CMOS, achieves peak output power and SE of 30.1 dBm and 37.0%, respectively. It achieves error vector magnitude (EVM) of -40.7 dB (-40.3 dB) and SE of 14.7% (18.3%) at an average output power of 19.5 dBm (22.5 dBm) with 802.11g 64-QAM OFDM signal with 10.6 dB peak-to-average power ratio (PAPR) (20-MHz single-carrier 256-QAM signal with 7.6-dB PAPR).
This article presents an efficient quadrature digital power amplifier (DPA) based on a complex-domain Doherty (CDD) architecture. The proposed CDD architecture allows a PA to achieve high efficiency ...through Doherty operation in a complex domain using two independent vectors with different amplitudes and phases. It demonstrates high efficiency when two vectors have in-phase components in the complex domain by introducing an additional efficiency peak. The proposed DPA based on a switch-capacitor PA (SCPA) employs the CDD and dual-supply Class-G techniques to enhance system efficiency (SE) and adds three additional efficiency peaks down to 12-dB power back-off (PBO). An additional efficiency peak at 6-dB PBO and two additional efficiency peaks at 2.5- and 12-dB PBOs are associated with CDD and Class-G, respectively. The prototype, fabricated in a 65-nm CMOS process, achieves 27.8-dBm peak output power (<inline-formula> <tex-math notation="LaTeX">P_{\mathrm {OUT}} </tex-math></inline-formula>) with a peak SE of 32.1%. It exhibits an error vector magnitude (EVM) of −42.0 dB (−43.3 dB) at a <inline-formula> <tex-math notation="LaTeX">P_{\mathrm {OUT}} </tex-math></inline-formula> of 14.7 dBm (15.4 dBm) for an 802.11ax 40-MHz (20-MHz) 1024-QAM OFDM signal with 13.1-dB (12.4-dB) peak-to-average power ratio (PAPR) at 2.2 GHz. The average SE measured with a 20-MHz single-carrier 1024-QAM signal with 6.8-dB PAPR at a <inline-formula> <tex-math notation="LaTeX">P_{\mathrm {OUT}} </tex-math></inline-formula> of 21 dBm is 18.4%.
As people age, their risks of developing degenerative diseases such as cancer, diabetes, Parkinson's Disease (PD), Alzheimer's Disease (AD), rheumatoid arthritis, and osteoporosis are generally ...increasing. Millions of people worldwide suffer from these diseases as they age. In most countries, neurodegenerative diseases are generally recognized as the number one cause afflicting the elderly. Endoplasmic reticulum (ER) stress has been suggested to be associated with some human neurological diseases, such as PD and AD. Melatonin, a neuroendocrine hormone mainly synthesized in the pineal gland, is involved in pleiotropically biological functions, including the control of the circadian rhythm, immune enhancement, and antioxidant, anti-aging, and anti-tumor effects. Although there are many papers on the prevention or suppression of diseases by melatonin, there are very few papers about the effects of melatonin on ER stress in neurons and neurodegenerative diseases. This paper aims to summarize and present the effects of melatonin reported so far, focusing on its effects on neurons and neurodegenerative diseases related to ER stress. Studies have shown that the primary target molecule of ER stress for melatonin is CHOP, and PERK and GRP78/BiP are the secondary target molecules. Therefore, melatonin is crucial in protecting neurons and treating neurodegeneration against ER stress.
Background
Initial experiences with robotic gastrectomy (RG) for gastric cancer have demonstrated favorable short-term outcomes, suggesting that RG is an effective alternative to laparoscopic ...gastrectomy (LG). However, data on long-term survival and recurrence after RG for gastric cancer have yet to be reported. The objective of this study was to assess long-term outcomes after RG compared with LG.
Methods
We retrospectively evaluated 313 and 524 patients who underwent RG or LG, respectively, for gastric cancer between July 2005 and December 2009. We compared long-term outcomes using the entire and a propensity-score matched cohort.
Results
The entire cohort analysis revealed no statistically significant differences in 5-year overall survival(OS) or relapse-free survival(RFS) (
p
= 0.4112 and
p
= 0.8733, respectively): 93.3% 95% confidence interval (CI) 89.9–95.6 and 90.7% (95% CI, 86.9–93.5) after RG and 91.6% (95% CI 88.9–93.7) and 90.5% (95% CI 87.6–92.7) after LG, respectively; hazard ratios for death and recurrence in the robotic group were 0.828 (95% CI, 0.528–1.299;
p
= 0.4119) and 0.968 (95% CI, 0.649–1.445;
p
= 0.8741), respectively. The propensity-matched cohort analysis demonstrated no statistically significant differences for 5-year OS or RFS (
p
= 0.5207 and
p
= 0.2293, respectively): 93.2% and 90.7% after RG and 94.2% and 92.6% after LG, respectively; hazard ratios for death and recurrence in the robotic group were 1.194 (95% CI, 0.695–2.062;
p
= 0.5214) and 1.343 (95% CI, 0.830–2.192;
p
= 0.2321), respectively.
Conclusion
The potential technical superiority of robotic system over laparoscopy did not improve oncological outcomes after gastrectomy. Long-term oncological outcomes were not different between RG and LG. Nevertheless, robotic applications in minimally invasive gastric cancer surgery may be an oncologically safe alternative.
Climate change, particularly drought stress, significantly impacts plant growth and development, necessitating the development of resilient crops. This study investigated physiological and molecular ...modulations to drought stress between diploid parent species and their polyploid progeny in the
species. While no significant phenotypic differences were observed among the six species, drought stress reduced growth parameters by 2.4% and increased oxidative stress markers by 1.4-fold. Drought also triggered the expression of genes related to stress responses and led to the accumulation of specific metabolites. We also conducted the first study of perfluorooctane sulfonic acid (PFOS) levels in leaves as a drought indicator. Lower levels of PFOS accumulation were linked to plants taking in less water under drought conditions. Both diploid and polyploid species responded to drought stress similarly, but there was a wide range of variation in their responses. In particular, responses were less variable in polyploid species than in diploid species. This suggests that their additional genomic components acquired through polyploidy may improve their flexibility to modulate stress responses. Despite the hybrid vigor common in polyploid species,
polyploids demonstrated intermediate responses to drought stress. Overall, this study lays the framework for future omics-level research, including transcriptome and proteomic studies, to deepen our understanding of drought tolerance mechanisms in
species.
Low-cost optical particle counters effectively measure particulate matter (PM) mass concentrations once calibrated. Sensor calibration can be established by deriving a linear regression model by ...performing side-by-side measurements with a reference instrument. However, calibration differences between environmental and occupational settings have not been demonstrated. This study evaluated four commercially available, low-cost PM sensors (OPC-N3, SPS30, AirBeam2, and PMS A003) in both settings. The mass concentrations of three aerosols (salt, Arizona road dust, and Poly-alpha-olefin-4 oil) were measured and compared with a reference instrument. OPC-N3 and SPS30 were highly correlated (r = 0.99) with the reference instrument for all aerosol types in environmental settings. In occupational settings, SPS30, AirBeam2, and PMS A003 exhibited high correlation (>0.96), but the OPC-N3 correlation varied (r = 0.88–1.00). Response significantly (p < 0.001) varied between environmental and occupational settings for most particle sizes and aerosol types. Biases varied by particle size and aerosol type. SPS30 and OPC-N3 exhibited low bias for environmental settings, but all of the sensors showed a high bias for occupational settings. For intra-instrumental precision, SPS30 exhibited high precision for salt for both settings compared to the other low-cost sensors and aerosol types. These findings suggest that SPS30 and OPC-N3 can provide a reasonable estimate of PM mass concentrations if calibrated differently for environmental and occupational settings using site-specific calibration factors.
A 30.0-dBm polar digital power amplifier (PA) is implemented based on a switched-capacitor PA (SCPA) and multiple efficiency-enhancement techniques, such as Class-G, Doherty, and time interleaving ...(TI). The PA demonstrates six efficiency peaks and seamless efficiency curves between the peaks in the power back-off (PBO) region with the three efficiency-enhancement techniques. For the implementation of the efficient and linear Class-G technique, a linear single-supply current-reuse Class-G switch is proposed. It realizes a Class-G operation without any additional dedicated supply voltages, resulting in enhanced efficiency and reduced cost for an external power management unit (PMU). A local oscillator (LO) signal restoration technique is proposed to reduce the area and power consumption for the LO signal distribution. The prototype SCPA, fabricated in a 65-nm CMOS, generates 30-dBm peak output power (<inline-formula> <tex-math notation="LaTeX">P_{\mathrm {OUT}} </tex-math></inline-formula>) at 2.4 GHz and achieves drain efficiency (DE) (normalized DE) of 40.2% (100%), 37.9% (94.3%), 38.8% (96.3%), 36.3% (90.2%), 29.4% (73.0%), and 19.7% (48.9%) at 0-, 2.5-, 6-, 8.5-, 12-, and 18-dB PBOs, respectively. It achieves less than ±1° amplitude modulation (AM)-phase modulation (PM) distortion with a continuous-wave (CW) signal. It also demonstrates error vector magnitude (EVM) of −41.7 dB (−44.5 dB) and DE of 30.3% (36.2%) at an average output power of 19.1 dBm (23.2 dBm) for a 10-MHz 64-quadrature AM (QAM) orthogonal frequency-division multiplexing (OFDM) signal with a 10.9-dB peak-to-average power ratio (PAPR) (10-MHz single-carrier 1024-QAM signal with 6.8-dB PAPR).
Autophagy has been implicated in the ageing process, but whether autophagy activation extends lifespan in mammals is unknown. Here we show that ubiquitous overexpression of Atg5, a protein essential ...for autophagosome formation, extends median lifespan of mice by 17.2%. We demonstrate that moderate overexpression of Atg5 in mice enhances autophagy, and that Atg5 transgenic mice showed anti-ageing phenotypes, including leanness, increased insulin sensitivity and improved motor function. Furthermore, mouse embryonic fibroblasts cultured from Atg5 transgenic mice are more tolerant to oxidative damage and cell death induced by oxidative stress, and this tolerance was reversible by treatment with an autophagy inhibitor. Our observations suggest that the leanness and lifespan extension in Atg5 transgenic mice may be the result of increased autophagic activity.
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