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Proteins are the carriers of biological structure and function, which are involved in almost all the physiological processes in organisms. The qualitative and quantitative analysis of proteins can not only help us understand the mechanisms of life activities, but also screen for the proteins with abnormal expression compared to healthy controls as biomarkers of diseases as well as environmental exposure to harmful substances, thus facilitating to unravel the mechanisms of disease generation and development. Tandem mass spectrometry (MS/MS) is currently the main tool for high-throughput proteomics analysis. It can characterize the proteins by determining the molecular mass of digestion products, locating modification sites, and obtaining sequence information. However, acidic amino acid residues often have a significant impact on the cleavage process of peptides, limiting the performance of MS/MS. For example, for the phosphopeptides containing abundance of negatively charged carboxyl and phosphoryl groups, their ionization is not efficient in the positive mode, and neutral loss is easy to occur during the cleavage process, resulting in a low coverage of product ions in the MS/MS spectra. In this paper, the carboxyl groups from the R group of aspartic acid and glutamic acid as well as the C-terminus of peptide were neutralized using dimethylamine derivatization under mild condition. Accordingly, the fragmentation features of peptides with altered charge properties were studied in collision-induced dissociation (CID) mode. Further, the peptides were labeled using light and heavy isotopic dimethylamine, respectively, thus enabling to verify the features based on the same ion with different labels. The results showed that the precursor ion signal from the derivatized peptide was significantly enhanced compared to that of the native peptide. And, the derived peptides could yield a variety of a, b, y, and z ions, and some reported ions in MS/MS analysis, such as the ion at m/z 129.10/135.14 produced by the peptides with glutamic acid or lysine residue at C-terminus, which facilitating to determine the C-terminal amino acid of protein. While, the peptides proned to lose the derivative groups located at the C-terminus, yielding a series of ions at m/z ［yn-45.06］ or ［yn-73.05］. In addition, the neutralization of carboxyl groups could suppress the loss of phosphoryl groups in phosphopeptides to a certain extent, thus improving the resolution efficiency of the MS/MS spectra. Overall, the derivatization method based on carboxy-amidation can provide abundant information for the sequence determination and quantitative analysis of peptides due to the altered fragmentation features in CID mode.

The international food trade is beneficial for enhancing global food security but also raises issues such as global cropland redistribution, land use efficiency, and environmental problems. While current studies have examined the impacts of the international food trade on these issues, its long-term effects on global cropland use efficiency remain unclear, especially when considering different crops and countries. Utilizing the international trade theory and the principle of virtual cropland, this study explores the relationship between international food trade and global cropland use efficiency from 2000 to 2022. The results illustrate that the global crop trade surged by 142%, outpacing the 102% increase in virtual cropland trade, which was attributed to crop yield enhancements. By 2022, the global virtual cropland trade encompassed 10.7% of the total croplands, with China emerging as the foremost importer, particularly due to soybean imports. Notably, the global crop trade led to substantial cropland savings and higher cropland use efficiency, totaling 1244.9 million hectares (Mha) between 2000 and 2020. These gains were largely attributed to the superior yields of major crop-exporting countries. Despite these gains, socio-economically vulnerable countries face significant challenges, potentially compromising their food security amidst the complexities of the global trade dynamics. [ABSTRACT FROM AUTHOR]

Sporotrichosis is a subacute or chronic infectious disease caused by sporothrix. It is mainly caused by Sporothrix inoculation after accidental skin injury during human labor. The clinical manifestations of sporotrichosis are variable, ranging from nodules, plaques, ulcers, verrucous lesions, and subcutaneous masses. Some reports indicate that sporotrichosis can mimic psoriasis-like lesions. We herein report a case of sporotrichosis mimicking rosacea lesions. In addition, the patient had a history of nasal trauma, and we believe that the patient was inoculated with Sporothrix after the nasal skin was damaged during labor activities. The patient was given itraconazole 200 mg orally daily for 3 months, which effectively resolved the rash. [ABSTRACT FROM AUTHOR]

As an irreplaceable ecological barrier, an ecological conservation developing area (ECDA) is vital for the integrated construction of urban and rural areas and the optimization and adjustment of industrial structures. However, few empirical studies have been conducted on the spatiotemporal variations of agricultural green development (AGD) in the ECDAs of large cities. Based on the green agricultural traits of Beijing and the accessible data, we evaluated the AGD and analyzed its spatial and temporal heterogeneity in Beijing's ECDAs by constructing a framework with 13 indicators. The results stated that energy consumption is a vital factor in green agriculture production and that the agricultural output value per unit of arable land area is the key to green agricultural revenue. From 2006 to 2016, the AGD index of the ECDA had an increasing trend, until 2012 when it followed a decreasing tendency. The AGD index of the northern region was higher than in the southern ECDA. The obstacle degree model was used to verify the AGD limiting factors, where poor infrastructure, slow agritourism, low labor productivity, and low resource use efficiency varied by districts in the ECDA. Given these findings, our study is conducive to AGD evaluation at the district (county) level for the ECDAs of large cities and provides important policy implications. [ABSTRACT FROM AUTHOR]

Psoriasis is a T-cell mediated disease that involves IL-23/Th17 and IL-12/Th1 axes. Ustekinumab, a fully human monoclonal antibody targeting the p40 subunit of both IL-12 and IL-23, has proven to be efficient and safe for treating patients with psoriasis. Yet, there have been no reports with human skin/blood samples that would elucidate the molecular mechanisms by which ustekinumab calms psoriasis skin lesions. To investigate the efficacy and molecular pathway (RORC, t-BOX and GATA) of ustekinumab in treating patients with psoriasis skin lesions. A total of 30 patients with psoriasis were randomized into placebo group and treatment group. PASI of each patient was calculated at 0, 12 and 24 weeks post-treatment. The mRNA levels of RORC, t-BOX and GATA in peripheral blood mononuclear cells separated from patients’ whole blood were analyzed using qPCR. Decreased mRNA of RORC, t-BOX and GATA were observed after continuous injections, indicating that ustekinumab exerts its effect by interacting with these molecules; while no significant difference in foxp3 mRNA levels were found between placebo group and treatment group.