Revisiting the Role of Label Smoothing in Enhanced Text Sentiment Classification

Label smoothing is a widely used technique in various domains, such as text classification, image classification and speech recognition, known for effectively combating model overfitting. However, there is little fine-grained analysis on how label smoothing enhances text sentiment classification. To fill in the gap, this article performs a set of in-depth analyses on eight datasets for text sentiment classification and three deep learning architectures: TextCNN, BERT, and RoBERTa, under two learning schemes: training from scratch and fine-tuning. By tuning the smoothing parameters, we can achieve improved performance on almost all datasets for each model architecture. We further investigate the benefits of label smoothing, finding that label smoothing can accelerate the convergence of deep models and make samples of different labels easily distinguishable.Comment: Technical Repor

CO2 dissociation activated through electron attachment on reduced rutile TiO2(110)-1x1 surface

Converting CO$_2$ to useful compounds through the solar photocatalytic reduction has been one of the most promising strategies for artificial carbon recycling. The highly relevant photocatalytic substrate for CO$_2$ conversion has been the popular TiO$_2$ surfaces. However, the lack of accurate fundamental parameters that determine the CO$_2$ reduction on TiO$_2$ has limited our ability to control these complicated photocatalysis processes. We have systematically studied the reduction of CO2 at specific sites of the rutile TiO$_2$(110)-1x1 surface using scanning tunneling microscopy at 80 K. The dissociation of CO2 molecules is found to be activated by one electron attachment process and its energy threshold, corresponding to the CO$_2^{\dot-}$/CO$_2$ redox potential, is unambiguously determined to be 2.3 eV higher than the onset of the TiO$_2$ conduction band. The dissociation rate as a function of electron injection energy is also provided. Such information can be used as practical guidelines for the design of effective catalysts for CO$_2$ photoreduction

Protective Role of Nuclear Factor-Erythroid 2-Related Factor 2 Against Radiation-Induced Lung Injury and Inflammation

Radiation-induced lung injury (RILI) is one of the most common and fatal complications of thoracic radiotherapy. Inflammatory cell infiltration, imbalance of inflammatory cytokines, and oxidative damage were reported to be involved during RILI pathogenesis, especially in the early phase of RILI. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key transcriptional regulator of antioxidative cascades, and regulates life span of mice after administration of thoracic irradiation. We investigated the effects of Nrf2 on RILI and inflammation using Nrf2-knockout, Nrf2-overexpression and wild-type mice with or without 15 Gy ionizing radiation to thorax. Our results showed that Nrf2 deficiency aggravated radiation-induced histopathological changes, macrophage and neutrophil infiltration, serum levels of pro-inflammatory cytokines (IL-6, MCP-1, IFN-γ, TNF, and IL-12p70), and the levels of peroxidation products in the mouse lung. Moreover, loss of Nrf2 reduced radiation-induced serum levels of anti-inflammatory cytokine, IL-10, and antioxidative proteins. Nrf2 overexpression significantly alleviated radiation-induced histopathological changes, macrophages and neutrophils infiltration, serum levels of pro-inflammatory cytokines, and the levels of peroxidation products in lung tissues. Nrf2 overexpression also increased the serum levels of IL-10 and antioxidative proteins. These results indicated that Nrf2 had a protective role against radiation-induced acute lung injury and inflammation, and that antioxidative therapy might be a promising treatment for RILI

N-of-1 Trial of Jianpiqingrehuashi Granular Decoction with Mesalamine in the Treatment of Ulcerative Colitis in Remission with Spleen Deficiency-induced Damp-heat Syndrome

BackgroundThe patient with ulcerative colitis (UC) in remission has a long course of disease, and needs a long-term maintenance treatment. Traditional Chinese medicine (TCM) has proved to be partially effective in treating UC in remission, but the efficacy of Jianpiqingrehuashi granular decoction (JPQRHSGD) against UC in remission is not yet clear.ObjectiveTo evaluate the efficacy and safety of JPQRHSGD with mesalamine versus mesalamine in the treatment of UC in remission using an N-of-1 trial.MethodsAn N-of-1 trial was conducted between June 2020 and March 2021. Participant was an outpatient with UC in remission with spleen deficiency-induced dampness-heat syndrome who was selected from the First Affiliated Hospital, Guangzhou University of Chinese Medicine. The patient received a treatment program, namely four rounds of treatment without washout consisting of eight cycles〔each round includes two cycles, that was, one-month intervention treatment (use of JPQRHSGD with mesalamine) alternating with one-month control treatment (taking mesalamine only) 〕. Efficaciesof two types of treatment were evaluated by of the TCM Syndrome Score (TCMSS) , Bristol Stool Form Scale (BSFS) , visual analogue scale (VAS) for abdominal pain and diarrhea, and Short Health Scale (SHS) . Safety was also compared between the two treatments.ResultsThe total TCMSS in intervention period was significantly lower than that in control period (P<0.05) . In particular, the symptoms of diarrhea, abdominal distension and fatigue of the limbs were improved more obviouslyin intervention period (P<0.05) . The improvements of total BSFS score, and diarrhea VAS score in intervention period were better than those in control period (P<0.05) . However, abdominal pain VAS score in intervention period was worse than that in control period (P<0.05) . The improvement of SHS score in intervention period was better than those in control period (P<0.05) . No treatment-related adverse events were reported.ConclusionThe JPQRHSGD with mesalamine improved the clinical symptoms of the UC patient in remission with spleen deficiency-induced dampness-heat syndrome, with relatively high safety

Homogenization of Halide Distribution and Carrier Dynamics in Alloyed Organic-Inorganic Perovskites

Perovskite solar cells have shown remarkable efficiencies beyond 22%, through organic and inorganic cation alloying. However, the role of alkali-metal cations is not well-understood. By using synchrotron-based nano-X-ray fluorescence and complementary measurements, we show that when adding RbI and/or CsI the halide distribution becomes homogenous. This homogenization translates into long-lived charge carrier decays, spatially homogenous carrier dynamics visualized by ultrafast microscopy, as well as improved photovoltaic device performance. We find that Rb and K phase-segregate in highly concentrated aggregates. Synchrotron-based X-ray-beam-induced current and electron-beam-induced current of solar cells show that Rb clusters do not contribute to the current and are recombination active. Our findings bring light to the beneficial effects of alkali metal halides in perovskites, and point at areas of weakness in the elemental composition of these complex perovskites, paving the way to improved performance in this rapidly growing family of materials for solar cell applications.Comment: updated author metadat

TGF-ß Sma/Mab Signaling Mutations Uncouple Reproductive Aging from Somatic Aging

Female reproductive cessation is one of the earliest age-related declines humans experience, occurring in mid-adulthood. Similarly, Caenorhabditis elegans' reproductive span is short relative to its total life span, with reproduction ceasing about a third into its 15–20 day adulthood. All of the known mutations and treatments that extend C. elegans' reproductive period also regulate longevity, suggesting that reproductive span is normally linked to life span. C. elegans has two canonical TGF-ß signaling pathways. We recently found that the TGF-ß Dauer pathway regulates longevity through the Insulin/IGF-1 Signaling (IIS) pathway; here we show that this pathway has a moderate effect on reproductive span. By contrast, TGF-ß Sma/Mab signaling mutants exhibit a substantially extended reproductive period, more than doubling reproductive span in some cases. Sma/Mab mutations extend reproductive span disproportionately to life span and act independently of known regulators of somatic aging, such as Insulin/IGF-1 Signaling and Dietary Restriction. This is the first discovery of a pathway that regulates reproductive span independently of longevity and the first identification of the TGF-ß Sma/Mab pathway as a regulator of reproductive aging. Our results suggest that longevity and reproductive span regulation can be uncoupled, although they appear to normally be linked through regulatory pathways

Understanding reproductive aging regulation and mechanisms using a Caenorhabditis elegans model

Human female reproductive capacity declines early in adulthood due to decreased oocyte quality, with higher rates of infertility, miscarriage, and birth defects especially after mid-30s. Recently, due to the work from our lab , the Kornfeld lab and the Ellis lab , C. elegans has emerged as a model to study reproductive aging. My thesis work focuses on (1) studying the genetic regulation of C. elegans reproductive cessation; (2) developing a systematic approach to analyze different steps involved in C. elegans reproductive aging; and (3) studying the underlying molecular mechanisms of reproductive aging. Insulin/IGF-1 signaling (IIS) is known to regulate reproductive span in C. elegans. We found that TGF-ß Sma/Mab signaling is a novel reproductive span regulator that acts independently of known somatic aging regulators. To discover the cause of C. elegans reproductive decline, we took a systematic approach and found that C. elegans reproductive span is also limited by oocyte quality, rather than ovulation rate, progeny number, or body size. Reduced TGF-ß Sma/Mab and IIS signaling delay reproductive aging through modulating multiple aspects of the reproductive process, including embryonic viability, oocyte fertilizability, chromosome segregation, DNA damage resistance, and morphology of the oocytes and germline. Furthermore, TGF-ß Sma/Mab and IIS pathways both act non-autonomously in the soma to regulate reproductive aging, and their activities are required at least partially in adulthood. To find the mechanisms of how the two pathways regulate oocyte quality, we performed microarrays comparing wild-type with TGF-ß Sma/Mab or IIS mutant oocytes, and comparing young with old wild-type oocytes. We found that several molecular functions are critical for C. elegans oocyte quality maintenance, such as chromosome segregation, cell cycle, and DNA damage response. These transcriptional analyses revealed that the TGF-ß Sma/Mab regulation of reproductive aging is separable from its control of body size, and that IIS regulates reproductive and somatic aging through distinct mechanisms. Additionally, the gene effectors associated with oocyte quality are conserved between C. elegans and humans, suggesting that the molecular mechanisms underlying their oocyte quality control are similar. Therefore our study may also provide insights into understanding the fundamental mechanisms of oocyte quality maintenance in humans

Graphene-Polyimide Nanocomposite Piezoresistive Thin Film Device for Strain and Pressure Measurement

In this thesis, piezoresistive thin film strain/pressure sensors made of graphene-polyimide (PI) nanocomposites with graphene concentration varies from 1.0wt% to 1.8wt% were fabricated, and their piezoresistive properties were characterized. The range of the graphene concentration is determined by percolation threshold theory, so the nanocomposites remain as semiconductors. The graphene-PI nanocomposites suspension were fabricated by blending method and was put into an ultrasonic water bath for a few hours to fully disperse the solution and avoid agglomeration of graphene nano-fillers. The graphene-PI nanocomposite thin film strain sensors were fabricated by depositing the suspensions on the polyimide substrate through a drop-on-demand piezoelectric inkjet printer, and electrodes were coated by sputter coater. The electrical impedance with respect to the strain that the nanocomposite thin films suffered under uniaxial tension and uniform pressure were monitored, and the gauge factor of these sensors under two experimental circumstances were calculated and compared. The respond of these strain sensor to pressure was also directly related. The temperature effect was evaluated, and the temperature coefficients of these graphene-PI nanocomposites devices were determined, and a feasible method to eliminate the temperature effect by temperature compensation was proposed. Finally, the most sensitive strain gauge represented by the largest gauge factor was found, proving that graphene-PI nanocomposites are superior materials than metals to fabricate high sensitive strain sensors, and inkjet printing technique is a desirable method to achieve this