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Aroma compounds are important flavor components in pear fruit. Among cultivated pears, fruits from (hereafter referred to as ) cultivars are famous for their abundant aroma, while the fruits of most (hereafter referred to as ) cultivars lack aroma compounds. A comparative study on the formation of differential aroma compounds between the two species could provide a theoretical foundation for improving the aroma quality of cultivars. However, there is a lack of systematic research on this subject. An analysis of volatile and non-volatile metabolites was combined with transcriptome analysis to explore the formation mechanism of differential aroma compounds between three and three cultivars. In this study, a total of 510 volatile compounds were identified in the six cultivars. Of these, sixteen ester and alcohol compounds, including butyl acetate, hexyl acetate, ethyl-2-methylbutyrate, ethanol, butanol, propanol, and 2-methylbutanol, with higher contents in the cultivars than in the cultivars were identified as the primary differential aroma compounds. Among the possible synthesis pathways for these 16 aroma compounds, certain amino acid degradation processes, including isoleucine, valine, and alanine oxidation and threonine dehydration, were found to provide important intermediate substances for synthesis. Within the key enzyme genes in the synthesis pathway, several critical enzyme genes, including monoacylglycerol lipase (PcMAGL, pycom08g09340), threonine dehydrase (PcTD, pycom12g10020), and acyl CoA dehydrogenase (PcACD, pycom16g13880), might be important factors contributing to the disparity in aromatic compounds between and cultivars. The aforementioned results provide valuable information into the formation mechanisms of differential aroma compounds and offer novel target sites for enhancing pear aroma quality through gene editing.

In the past decade, two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted increasing attention because of their striking physical properties and extensive applicability. Meanwhile, Raman spectroscopy has been demonstrated to be a feasible tool and is extensively employed in research on 2D TMDs. In recent years, the deployment of Raman spectroscopy under extreme conditions has elucidated the physical properties of TMDs. In this review, we focus on the extreme-condition Raman spectroscopy of typical group-VI TMDs, which are classified and discussed under the three extreme conditions of low temperature, high pressure and high magnetic field. The conclusion presents the most pressing challenges and attractive future opportunities in this rapidly developing research field.

Lymph nodes are crucial for perioperative immunotherapy but have to be completely resected in surgery. Trials evaluating the safety and necessity of omitting systemic mediastinal lymph node (mLN) dissection in non-small cell lung cancer (NSCLC) are still absent. cN0/N1 NSCLC patients who received neoadjuvant immunotherapy and radical surgery were retrospectively collected from three institutions. Restricted cubic spline regression and receiver operating characteristic curve were used to analyze the association between mLN dissection number and survival outcomes. Confounding factors between selective and systemic mLN dissection groups were adjusted by inverse probability of treatment weighting (IPTW). The characteristics of memory CD8 T cells in immunotherapy-treated mLN were identified by single-cell RNA and T-cell receptor sequencing (scRNA/TCR-seq) data retrieved from GSE185206. From 2019 to 2021, 131 neoadjuvant-treated cN0/N1 NSCLC patients were collected. The mLN clearance rate was 98.5% in the whole cohort and 100% in patients with radiologically confirmed complete response. Resected lymph node counts were irrelevant with local recurrence, distant metastasis, or death. Compared with selective mLN dissection, systemic mLN dissection did not show any survival benefit but showed slightly higher postoperative recurrence risk in both unadjusted and IPTW-adjusted cohorts. scRNA/TCR-seq showed that stem-like exhausted CD8 memory T cells were the progenitors of tumor-specific CD8 T lymphocytes in primary tumors and were abundantly enriched in resected mLN. Omitting systemic mLN dissection was safe in cN0/N1 NSCLC patients who received neoadjuvant immunotherapy. Excessive mLN dissection may disrupt the repertoire of stem-like exhausted CD8 memory T cells and consequently impair the efficacy of adjuvant immunotherapy.

Background Brain metastasis (BM) remains a major therapeutic challenge in non-small cell lung cancer (NSCLC) without actionable driver mutations. Radiotherapy combined with immune checkpoint inhibitors (ICIs) may enhance intracranial control through synergistic immune activation. This study evaluated the efficacy of radiotherapy plus ICI and explored prognostic factors influencing outcomes in patients with NSCLC-BM. Methods We retrospectively analyzed 116 patients with measurable, driver-negative NSCLC-BM treated between June 2019 and December 2024. Patients were divided into two groups: Radiotherapy combined with ICI plus chemotherapy (RT + ICI, n  = 56) and ICI plus chemotherapy (ICI, n  = 60). Intracranial and systemic objective response rates (iORR, sORR) and progression-free survival (iPFS, sPFS) were analyzed. Prognostic factors, including the prognostic nutritional index (PNI), were assessed using Cox regression analyses. Results Compared with the ICI group, the RT + ICI group demonstrated a significantly higher iORR (78.6% vs 40.0%, P  < 0.001) and significantly longer median iPFS (11.8 vs 7.9 months; hazard ratio [HR] = 0.48, 95% confidence intervals [CI] 0.30–0.77, P  = 0.002), and sPFS (8.9 vs 5.9 months; HR = 0.58, 95% CI 0.38–0.89, P  = 0.014). High PNI (≥ 42.15) was independently associated with prolonged iPFS (HR = 8.77, 95% CI 2.91–26.47, P  < 0.001) and sPFS (HR = 8.46, 95% CI 3.39–21.10, P  < 0.001). Conclusion Radiotherapy combined with immunochemotherapy was associated with improved intracranial and systemic outcomes compared to immunochemotherapy alone in patients with driver-negative NSCLC-BM. Additionally, PNI shows potential as a useful biomarker for predicting therapeutic outcomes.

Ultra-high-performance concrete with coarse aggregates (UHPC-CA) has the advantages of high strength, strong shrinkage resistance and a lower production cost, presenting a broad application prospect in civil engineering construction. In view of the difficulty in establishing a mathematical model to accurately predict the mechanical properties of UHPC-CA, the back-propagation artificial neural network (BP-ANN) method is used to fully consider the various influential factors of the compressive strength (CS) and flexural strength (FS) of UHPC-CA in this paper. By taking the content of cement (C), silica fume (SF), slag, fly ash (FA), coarse aggregate (CA), steel fiber, the water–binder ratio (w/b), the sand rate (SR), the cement type (CT), and the curing method (CM) as input variables, and the CS and FS of UHPC-CA as output objectives, the BP-ANN model with three layers has been well-trained, validated and tested with 220 experimental data in the studies published in the literature. Four evaluating indicators including the determination coefficient (R2), the root mean square error (RMSE), the mean absolute percentage error (MAPE), and the integral absolute error (IAE) were used to evaluate the prediction accuracy of the BP-ANN model. A parametric study for the various influential factors on the CS and FS of UHPC-CA was conducted using the BP-ANN model and the corresponding influential mechanisms were analyzed. Finally, the inclusion levels for the CA, steel fiber, and the dimensionless parameters of the W/B and sand rate were recommended to obtain the optimal strength of UHPC-CA.

The quaternized of N-aryl chitosan (CTS) derivatives containing different aromatic moieties were synthesized by two steps, N-aromatic Schiff and the quaternization. The chemical structures of all chitosan derivatives, N-vanillin Schiff’s base chitosan (NVCh), N-cinnamaldehyde Schiff’s base chitosan (NCCh), N-benzaldehyde Schiff’s base CTS (NBCh), and their quaternized of N-aromatic CTS derivatives were characterized by ATR-FTIR. The water solubility of the N-aromatic Schiff’s base CTS derivatives had very poor water solubility. But after quaternized, the water solubility of CTS derivatives was obviously improved. The antibacterial studies of these CTS derivatives were carried out by the inhibition zone diameters methods against E.coli (Gram-negative), S.aurueus and P.aeruginosa (Gram-positive) bacteria, and against V.Aspergillus niger (fungal). It was found that the quaternized NVSCTS showed higher antibacterial activity than quaternized NCCh and quaternized NVBCh at the almost same DQ and ES level. In comparison to each of the chemical structure, it was found that the phenol hydroxyl group effect on antibacterial activity was even higher than that of positive charge density of CTS.

The wastewater from electronics industry is different from urban sewage and most industrial wastewater, with less organic matter and worse degradability. [...]Si, Ca, Mg , Sr and AI contents are high, with complex form. Various organic matters and colloidal particles in effluent of MBR may adhere to RO membrane surface, forming gel layer pollution , while various inorganic ions which could not be effectively intercepted by MBR may form deposit on RO membrane surface. [...]the key of design and long-term stable operation of MBR + RO whole treatment system is clearing pollution characteristics of MBR effluent. According to research results of Uu Zheng et at. [sJ , it was characteristic peak of fulvic acid in visible region with hydrophobicity and stable structure at A.,. =280 nrniA.,. =410 nm (Peak 2) . EDTA belongs to anionic organic chelating detergent and could form stable complex compound with two-valence and trivalent metal ions. [...]it has strong cleaning effect on metal compound.

During the last decades the development of the transistor and its continuous down-scaling allowed the appearance of cost effective wireless communication systems. New generation wideband wireless mobile systems demand high linearity, low power consumption and the low cost devices. Traditional RF systems are mainly analog-based circuitry. Contrary to digital circuits, the technology scaling results in reduction on the maximum voltage swing which makes RF design very challenging. Pushing the interface between the digital and analog boundary of the RF systems closer to the antenna becomes an attractive trend for modern RF devices. In order to take full advantages of the deep submicron CMOS technologies and digital signal processing (DSP), there is a strong trend towards the development of digital transmitter where the RF up-conversion is part of the digital-to-analog conversion (DAC). This thesis presents a new digital intermediate frequency (IF) to RF transmitter for 2GHz wideband code division multiple access (W-CDMA). The proposed transmitter integrates a 3-level digital IF current-steering cell, an up-conversion mixer with a tuned load and an RF variable gain amplifier (RF VGA) with an embedded finite impulse response (FIR) reconstruction filter in the up-conversion path. A 4th-order 1.5-bit IF bandpass sigma delta modulator (BP ΣΔM) is designed to support in-band SNR while the out-of-band quantization noise due to the noise shaping is suppressed by the embedded reconstruction filter to meet spectrum emission mask and ACPR requirements. The RF VGA provides 50dB power scaling in 10-dB steps with less than 1dB gain error. The design is fabricated in a 0.18µm CMOS technology with a total core area of 0.8 x 1.6 mm2. The IC delivers 0dBm output power at 2GHz and it draws approximately 120mA from a 1.8V DC supply at the maximum output power. The measurement results proved that a digital-intensive digital IF to RF converter architecture can be successfully employed for W-CDMA transmitter application.

Experiments were performed in a simulated combustion chamber with non-combustible and combustible mixtures to study the feasibility of spark plug based diagnostics for fuel-air ratio determination in the spark plug gap of a Spark Ignition (SI) engine at ignition. During the experiments, the breakdown voltage (V $\\rm\\sb{s}$ ) as well as the spark light emission were measured to correlate to the characteristics of the gas mixture. A simulated combustion chamber was used rather than an actual engine to obtain better control of mixture composition and other experimental parameters. The dependence of V $\\rm\\sb{s}$on the pressure, the temperature, the gas composition and the gap size was tested in non-combustible mixtures by measuring the true values of V $\\rm\\sb{s}$and the agreement between the experimental results and Paschen's Law was studied. In addition, the correlation between V $\\rm\\sb{s}$and the fuel-air equivalence ratio ( $\\phi$ ), as well as the residual gas fraction (RGF) was tested in combustible mixtures. In the measurements of spark light intensities, relative intensity (the spectral intensity of a particular molecule normalized by the shot or broadband intensity) was studied to reduce the effect of the variations of orientation of the spark initiation. The relative intensity of the CN radical, centered at 385 nm, was tested to have the strongest intensity 5$\\mu$ s after the spark ignition compared to those of the other radicals, such as CH and NH. It has also been found that the relative intensity of CN has great dependence on$\\phi$as well as RGF. The study of this spark plug based diagnostics provides a feasible method for determination of mixture composition in the spark plug gap at ignition.

Certain low pathogenic avian influenza viruses can mutate to highly pathogenic viruses when they circulate in domestic poultry, at which point they can cause devastating poultry diseases and severe economic damage. The H7N9 influenza viruses that emerged in 2013 in China had caused severe human infections and deaths. However, these viruses were nonlethal in poultry. It is unknown whether the H7N9 viruses can acquire additional mutations during their circulation in nature and become lethal to poultry and more dangerous for humans. Here, we evaluated the evolution of H7N9 viruses isolated from avian species between 2013 and 2017 in China and found 23 different genotypes, 7 of which were detected only in ducks and were genetically distinct from the other 16 genotypes that evolved from the 2013 H7N9 viruses. Importantly, some H7N9 viruses obtained an insertion of four amino acids in their hemagglutinin （HA） cleavage site and were lethal in chickens. The index strain was not lethal in mice or ferrets, but readily obtained the 627K or 701N mutation in its PB2 segment upon replication in ferrets, causing it to become highly lethal in mice and ferrets and to be transmitted efficiently in ferrets by respiratory droplet. H7N9 viruses bearing the HA insertion and PB2 627K mutation have been detected in humans in China. Our study indicates that the new H7N9 mutants are lethal to chickens and pose an increased threat to human health, and thus highlights the need to control and eradicate the H7N9 viruses to prevent a possible pandemic.