•Methanol-soluble OC represents the vast majority of total OC mass.•Brown coating on BC cores reduces the lensing effect relative to clear coating.•The reduction in lensing is overwhelmed by BrC ...shell absorption.•EC mass is underestimated by up to 50% due to charring-induced uncertainties.•Methanol extraction improves EC measurements by reducing char-OC formation.
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Brown carbon (BrC) is increasingly included in climate models as an emerging category of particulate organic compounds that can absorb solar radiation efficiently at specific wavelengths. Water-soluble organic carbon (WSOC) has been commonly used as a surrogate for BrC; however, it only represents a limited fraction of total organic carbon (OC) mass, which could be as low as about 20% in urban atmosphere. Using methanol as the extraction solvent, up to approximately 90% of the OC in Beijing aerosol was isolated and measured for absorption spectra over the ultraviolet-to-visible wavelength range. Compared to methanol-soluble OC (MSOC), WSOC underestimated BrC absorption by about 50% at 365nm. The mass absorption efficiencies measured for BrC in Beijing aerosol were converted to the imaginary refractive indices of BrC and subsequently used to compute BrC coating-induced enhancement of light absorption (Eabs) by black carbon. Eabs attributed to lensing was reduced in the case of BrC coating relative to that caused by purely-scattering coating. However, this reduction was overwhelmed by the effect of BrC shell absorption, indicating that the overall effect of BrC coating was an increase in Eabs. Methanol extraction significantly reduced charring of OC during thermal-optical analysis, leading to a large increase in the measured elemental carbon (EC) mass and an apparent improvement in the consistency of EC measurements by different thermal-optical methods.
The electrical and optical measurements, in combination with density functional theory calculations, show distinct layer‐dependent semiconductor‐to‐semimetal evolution of 2D layered PtSe2. The high ...room‐temperature electron mobility and near‐infrared photoresponse, together with much better air‐stability, make PtSe2 a versatile electronic 2D layered material.
•Obtain an important theorem about discordance indices for any two alternatives.•Some desirable properties of outranking relations for ELECTRE I and II are discussed.•Analyzes the sensitivity of the ...criteria weights in classical ELECTRE I and II.
In this study, the ranges of criteria weights based on the outranking relations in ELECTRE I and II methods are analyzed, which is considered as the sensitivity analysis regarding criteria weights. First, an important theorem is proved, in which the maximum value of discordance indices for any two alternatives is shown to be equal to 1. Using this theorem, four situations of outranking relations for any two alternatives are simplified to two situations when sensitivity analysis of criteria weights is performed for ELECTRE I. Subsequently, some inequalities are obtained to calculate the ranges of criteria weights when keeping the outranking relations between any two alternatives unchanged. For ELECTRE II, nine situations of strong and weak outranking relations are simplified into three situations of relations according to this theorem. The ranges of criteria weights are also derived when the strong and weak outranking relations remain unchanged. Finally, two examples are presented to test and verify the effectiveness of the sensitivity analysis of criteria weights for ELECTRE I. Two analogous examples are also presented in ELECTRE II.
Material that can emit broad spectral wavelengths covering deep ultraviolet, visible, and near-infrared is highly desirable. It can lead to important applications such as broadband modulators, ...photodetectors, solar cells, bioimaging, and fiber communications. However, there is currently no material that meets such desirable requirement. Here, we report the layered structure of nitrogen-doped graphene quantum dots (N-GQDs) which possess broadband emission ranging from 300 to >1000 nm. The broadband emission is attributed to the layered structure of the N-GQDs that contains a large conjugated system and provides extensive delocalized π electrons. In addition, a broadband photodetector with responsivity as high as 325 V/W is demonstrated by coating N-GQDs onto interdigital gold electrodes. The unusual negative photocurrent is observed which is attributed to the trapping sites induced by the self-passivated surface states in the N-GQDs.
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Ischemia-reperfusion (I/R) injury is accompanied with high morbidity and mortality and has seriously negative social and economic influences. Unfortunately, few effective therapeutic ...strategies are available to improve its outcome. Berberine is a natural medicine possessing multiple beneficial biological activities. Emerging evidence indicates that berberine has potential protective effects against I/R injury in brain, heart, kidney, liver, intestine and testis. However, up-to-date review focusing on the beneficial role of berberine against I/R injury is not yet available. In this paper, results from animal models and clinical studies are concisely presented and its mechanisms are discussed. We found that berberine ameliorates I/R injury in animal models via its anti-oxidant, anti-apoptotic and anti-inflammatory effects. Moreover, berberine also attenuates I/R injury by suppressing endoplasmic reticulum stress and promoting autophagy. Additionally, regulation of periphery immune system may also contributes to the beneficial effect of berberine against I/R injury. Although clinical evidence is limited, the current studies indicate that berberine may attenuate I/R injury via inhibiting excessive inflammatory response in patients. Collectively, berberine might be used as an alternative therapeutic strategy for the management of I/R injury.
Paclitaxel-induced neuropathic pain (PINP) is refractory to currently used analgesics. Previous studies show a pivotal role of oxidative stress in PINP. Because the nuclear factor erythroid-2-related ...factor 2 (Nrf2) has been considered as the critical regulator of endogenous antioxidant defense, we here explored whether activation of Nrf2 could attenuate PINP. A rat model of PINP was established by intraperitoneal injection of paclitaxel (2 mg/kg) every other day with a final cumulative dose of 8 mg/kg. Hind paw withdrawal thresholds (PWTs) in response to von Frey filament stimuli were used to assess mechanical allodynia. We showed that a single dose of Nrf2 activator, oltipraz (10, 50, and 100 mg/kg), dose-dependently attenuated established mechanical allodynia, whereas repeated injection of oltipraz (100 mg· kg
· d
, i.p. from d 14 to d 18) almost abolished the mechanical allodynia in PINP rats. The antinociceptive effect of oltipraz was blocked by pre-injection of Nrf2 inhibitor trigonelline (20 mg/kg, i.p.). Early treatment with oltipraz (100 mg· kg
· d
, i.p. from d 0 to d 6) failed to prevent the development of the PINP, but delayed its onset. Western blot and immunofluorescence analysis revealed that the expression levels of Nrf2 and HO-1 were significantly upregulated in the spinal cord of PINP rats. Repeated injection of oltipraz caused further elevation of the expression levels of Nrf2 and HO-1 in the spinal cord of PINP rats, which was reversed by pre-injection of trigonelline. These results demonstrate that oltipraz ameliorates PINP via activating Nrf2/HO-1-signaling pathway in the spinal cord.
Molybdenum disulphide (MoS2), which is a typical semiconductor from the family of layered transition metal dichalcogenides (TMDs), is an attractive material for optoelectronic and photodetection ...applications because of its tunable bandgap and high quantum luminescence efficiency. Although a high photoresponsivity of 880-2000 AW(-1) and photogain up to 5000 have been demonstrated in MoS2-based photodetectors, the light absorption and gain mechanisms are two fundamental issues preventing these materials from further improvement. In addition, it is still debated whether monolayer or multilayer MoS2 could deliver better performance. Here, we demonstrate a photoresponsivity of approximately 10(4) AW(-1) and a photogain of approximately 10(7) electrons per photon in an n-n heterostructure photodetector that consists of a multilayer MoS2 thin film covered with a thin layer of graphene quantum dots (GQDs). The enhanced light-matter interaction results from effective charge transfer and the re-absorption of photons, leading to enhanced light absorption and the creation of electron-hole pairs. It is feasible to scale up the device and obtain a fast response, thus making it one step closer to practical applications.
Non‐small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer. Cisplatin is commonly used in the treatment of many malignant tumours including NSCLC. The innate drug sensitivity ...greatly affects the clinical efficacy of cisplatin‐based chemotherapy. As a plasma membrane adhesion molecule, amphoterin‐induced gene and ORF‐2 (AMIGO2) initially identified as a neurite outgrowth factor has been recently found to play a crucial role in cancer occurrence and progression. However, it is still unclear whether AMIGO2 is involved in innate cisplatin sensitivity. In the present study, we provided the in vitro and in vivo evidences indicating that the alteration of AMIGO2 expression triggered changes of innate cisplatin sensitivity as well as cisplatin‐induced pyroptosis in NSCLC. Further results revealed that AMIGO2 might inhibit cisplatin‐induced activation of (caspase‐8 and caspase‐9)/caspase‐3 via stimulating PDK1/Akt (T308) signalling axis, resulting in suppression of GSDME cleavage and the subsequent cell pyroptosis, thereby decreasing the sensitivity of NSCLC cells to cisplatin treatment. The results provided a new insight that AMIGO2 regulated the innate cisplatin sensitivity of NSCLC through GSDME‐mediated pyroptosis.
Inducing homologous-recombination (HR) deficiency is an effective strategy to broaden the indications of PARP inhibitors in the treatment of triple-negative breast cancer (TNBC). Herein, we find that ...repression of the oncogenic transcription factor FOXM1 using FOXM1 shRNA or FOXM1 inhibitor FDI-6 can sensitize BRCA-proficient TNBC to PARP inhibitor Olaparib in vitro and in vivo. Mechanistic studies show that Olaparib causes adaptive resistance by arresting the cell cycle at S and G
/M phases for HR repair, increasing the expression of CDK6, CCND1, CDK1, CCNA1, CCNB1, and CDC25B to promote cell cycle progression, and inducing the overexpression of FOXM1, PARP1/2, BRCA1/2, and Rad51 to activate precise repair of damaged DNA. FDI-6 inhibits the expression of FOXM1, PARP1/2, and genes involved in cell cycle control and DNA damage repair to sensitize TNBC cells to Olaparib by blocking cell cycle progression and DNA damage repair. Simultaneously targeting FOXM1 and PARP1/2 is an innovative therapy for more patients with TNBC.
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