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1.
Proc Natl Acad Sci U S A ; 120(40): e2304096120, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37748052

RESUMO

Eight extant species of pangolins are currently recognized. Recent studies found that two mitochondrial haplotypes identified in confiscations in Hong Kong could not be assigned to any known pangolin species, implying the existence of a species. Here, we report that two additional mitochondrial haplotypes identified in independent confiscations from Yunnan align with the putative species haplotypes supporting the existence of this mysterious species/population. To verify the new species scenario we performed a comprehensive analysis of scale characteristics and 138 whole genomes representing all recognized pangolin species and the cryptic new species, 98 of which were generated here. Our morphometric results clearly attributed this cryptic species to Asian pangolins (Manis sp.) and the genomic data provide robust and compelling evidence that it is a pangolin species distinct from those recognized previously, which separated from the Philippine pangolin and Malayan pangolin over 5 Mya. Our study provides a solid genomic basis for its formal recognition as the ninth pangolin species or the fifth Asian one, supporting a new taxonomic classification of pangolins. The effects of glacial climate changes and recent anthropogenic activities driven by illegal trade are inferred to have caused its population decline with the genomic signatures showing low genetic diversity, a high level of inbreeding, and high genetic load. Our finding greatly expands current knowledge of pangolin diversity and evolution and has vital implications for conservation efforts to prevent the extinction of this enigmatic and endangered species from the wild.


Assuntos
Genômica , Pangolins , Animais , Efeitos Antropogênicos , Ásia , China , Pangolins/genética , Crescimento Demográfico
2.
Liver Int ; 44(4): 979-995, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38293784

RESUMO

BACKGROUND & AIMS: Accumulating evidences suggest tumour microenvironment (TME) profoundly influence clinical outcome in hepatocellular carcinoma (HCC). Existing immune subtypes are susceptible to batch effects, and integrative analysis of bulk and single-cell transcriptome is helpful to recognize immune subtypes and TME in HCC. METHODS: Based on the relative expression ordering (REO) of 1259 immune-related genes, an immuno-prognostic signature was developed and validated in 907 HCC samples from five bulk transcriptomic cohorts, including 72 in-house samples. The machine learning models based on subtype-specific gene pairs with stable REOs were constructed to jointly predict immuno-prognostic subtypes in single-cell RNA-seq data and validated in another single-cell data. Then, cancer characteristics, immune landscape, underlying mechanism and therapeutic benefits between subtypes were analysed. RESULTS: An immune-related signature with 29 gene pairs stratified HCC samples individually into two risk subgroups (C1 and C2), which was an independent prognostic factor for overall survival. The machine learning models verified the immune subtypes from five bulk cohorts to two single-cell transcriptomic data. Integrative analysis revealed that C1 had poorer outcomes, higher CNV burden and malignant scores, higher sensitivity to sorafenib, and exhibited an immunosuppressive phenotype with more regulators, e.g., myeloid-derived suppressor cells (MDSCs), Mø_SPP1, while C2 was characterized with better outcomes, higher metabolism, more benefit from immunotherapy, and displayed active immune with more effectors, e.g., tumour infiltrating lymphocyte and dendritic cell. Moreover, both two single-cell data revealed the crosstalk of SPP1-related L-R pairs between cancer and immune cells, especially SPP1-CD44, might lead to immunosuppression in C1. CONCLUSIONS: The REO-based immuno-prognostic subtypes were conducive to individualized prognosis prediction and treatment options for HCC. This study paved the way for understanding TME heterogeneity between immuno-prognostic subtypes of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Transcriptoma , Microambiente Tumoral/genética , Neoplasias Hepáticas/genética , Prognóstico
3.
Opt Express ; 31(2): 2602-2620, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36785270

RESUMO

This paper investigates a method for measuring SO2 concentration using Fabry-Perot interferometer correlation spectroscopy. In this method, the experimental system is designed as a separated beam, with the beam entering the F-P cavity at two incidence angles simultaneously to match the peak and valley positions of the SO2 absorption cross-section. The system achieves a 2σ detection limit of 28.2 ppm·m(15 cm) at a sampling frequency of 10 Hz. An outfield comparison experiment with the differential optical absorption spectroscopy method shows good agreement for the simultaneous measurement of SO2 concentration from sulfur combustion, with a correlation coefficient of R2 = 0.93. This study introduces a non-dispersive, highly accurate, and fast gas detection technique.

4.
J Magn Reson Imaging ; 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37840197

RESUMO

BACKGROUND: Macrotrabecular-massive hepatocellular carcinoma (MTM-HCC) is highly aggressive. Comparing the diagnosis ability of CT and gadoxetate disodium (Gd-EOB-DTPA) MRI for MTM-HCC are lacking. PURPOSE: To compare the performance of Gd-EOB-DTPA MRI and CT for differentiating MTM-HCC from non-MTM-HCC, and determine the prognostic indicator. STUDY TYPE: Retrospective. SUBJECTS: Post-surgery HCC patients, divided into the training (N = 272) and external validation (N = 44) cohorts. FIELD STRENGTH/SEQUENCE: 3.0 T, T1-weighted imaging, in-opp phase, and T1-weighted volumetric interpolated breath-hold examination/liver acquisition with volume acceleration; enhanced CT. ASSESSMENT: Three radiologists evaluated clinical characteristics (sex, age, liver disease, liver function, blood routine, alpha-fetoprotein [AFP] and prothrombin time international normalization ratio [PT-INR]) and imaging features (tumor length, intratumor fat, hemorrhage, arterial phase peritumoral enhancement, intratumor necrosis or ischemia, capsule, and peritumoral hepatobiliary phase [HBP] hypointensity). Compared the performance of CT and MRI for diagnosing MTM-HCC. Follow-up occurred every 3-6 months, and nomogram demonstrated the probability of MTM-HCC. STATISTICAL TESTS: Fisher test, t-test or Wilcoxon rank-sum test, area under the curve (AUC), 95% confidence interval (CI), multivariable logistic regression, Kaplan-Meier curve, and Cox proportional hazards. Significance level: P < 0.05. RESULTS: Gd-EOB-DTPA MRI (AUC: 0.793; 95% CI, 0.740-0.839) outperformed CT (AUC: 0.747; 95% CI, 0.691-0.797) in the training cohort. The nomogram, incorporating AFP, PT-INR, and MRI features (non-intratumor fat, incomplete capsule, intratumor necrosis or ischemia, and peritumoral HBP hypointensity) demonstrated powerful performance for diagnosing MTM-HCC with an AUC of 0.826 (95% CI, 0.631-1.000) in the external validation cohort. Median follow-up was 347 days (interquartile range [IQR], 606 days) for the training cohort and 222 days (IQR, 441 days) for external validation cohort. Intratumor necrosis or ischemia was an independent indicator for poor prognosis. DATA CONCLUSION: Gd-EOB-DTPA MRI might assist in preoperative diagnosis of MTM-HCC, and intratumor necrosis or ischemia was associated with poor prognosis. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.

5.
Neuropathol Appl Neurobiol ; 48(4): e12795, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35156226

RESUMO

AIMS: CD47 is overexpressed in multiple tumours and plays an important role in immune escape and other biological processes of tumours. However, its role in adamantinomatous craniopharyngioma (ACP) remains unclear. Therefore, we explored the functions of CD47 in ACP. METHODS: In this study, the expression of CD47 and the infiltration of immune cells in ACP was determined by immunohistochemistry (IHC) or immunofluorescence. Microglia-mediated phagocytosis was analysed using an in vitro phagocytosis assay. Using lentivirus transfection, CD47 was either silenced or overexpressed in primary ACP cells and the biological effects of CD47 on these cells were evaluated in vitro using cell viability, flow cytometry, wound healing, Transwell migration and 3D hydrogel assays. The protein expression levels were analysed by western blotting. RESULTS: Finger-like protrusions, which may be the key factor in the recurrence of ACP, were primarily found in the region of hypothalamic involvement. The expression of CD47 was higher in palisading epithelium compared with stellate reticulum and epithelial whorls. An in vitro phagocytosis assay showed that CD47 blockade could promote microglia-mediated phagocytosis. Functional assays revealed that CD47 promoted the growth, migration and invasion of ACP cells in vitro. Our mechanistic investigations showed that CD47 activated the MAPK/ERK pathway, thereby facilitating the biological behaviour of ACP cells. CONCLUSIONS: Here, we demonstrated that CD47 plays an important role in ACP cells, suggesting that CD47 could be a new potential therapeutic target for ACP, and adding to the body of literature a role for the inhibition of MAPK/ERK in ACP.


Assuntos
Craniofaringioma , Neoplasias Hipofisárias , Antígeno CD47/metabolismo , Proliferação de Células , Humanos , Sistema de Sinalização das MAP Quinases , Microglia/patologia , Fagocitose , Neoplasias Hipofisárias/patologia
6.
Neuroendocrinology ; 112(9): 917-926, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34915523

RESUMO

INTRODUCTION: Insulin-like growth factor type 1 receptor (IGF1R) is overexpressed in various malignant tumors, which relates to their transformation and recurrence. Craniopharyngioma is a benign tumor with malignant results, often accompanied by a severe inflammatory reaction. However, the relationship between IGF1R expression and the inflammatory response of craniopharyngioma is unclear. METHODS: We enrolled 85 patients with adamantinomatous craniopharyngioma (ACP) in a study to explore the relationship between IGF1R expression and clinical features of this disease. RESULTS: Patients in the IGF1R high-expression group had a significantly higher incidence of hypopituitarism, higher recurrence rate, and lower progression-free survival. ß-Catenin can further regulate expression of the stem cell marker, CD44, by regulating IGF1R. Using immunofluorescence, we found that tumor stem cell-like cells did not express phosphorylated (p)-ERK, although p-ERK activation was evident in the surrounding cells. Picropodophyllin, a specific inhibitor of IGF1R, increased the expression of p-ERK protein and decreased the transcription level of interleukin-6. CONCLUSIONS: High expression of IGF1R might promote inflammation of ACP, which might be an unfavorable factor for pituitary function and prognosis. The high expression of IGF1R in tumor stem cell-like cells might inhibit the expression of p-ERK and promote the generation of inflammatory factors. IGF1R plays a stemness maintenance role in ACP and regulates the production of inflammatory factors through a p-ERK pathway, which suggests that targeting IGF1R and p-ERK might provide a new direction for alleviating tumor inflammation.


Assuntos
Craniofaringioma , Neoplasias Hipofisárias , Receptor IGF Tipo 1 , Craniofaringioma/patologia , Humanos , Inflamação/metabolismo , Hipófise/metabolismo , Neoplasias Hipofisárias/patologia , Receptor IGF Tipo 1/metabolismo
7.
Phys Chem Chem Phys ; 24(9): 5690-5699, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35187550

RESUMO

To combine both electride and alkalide characteristics in one molecular switch, it is shown herein that the phenalenyl radical and the M3 ring (M3-PHY, M = Li, Na, and K) stacked with parallel and vertical geometries are good candidates. The former geometry is the superalkali electride e-⋯M3+-PHY while the latter geometry is the superalkalide Mδ--M2(1-δ)+-PHY-. The superalkalide Mδ--M2(1-δ)+-PHY- may isomerize to the superalkali electride e-⋯M3+-PHY (M = Li, Na, and K) using suitable long-wavelength irradiation, while the latter may isomerize to the former with suitable short-wavelength irradiation. Also, applying suitable oriented external electric fields can drive the superalkalide Mδ-M2(1-δ)+-PHY- to change into the superalkali electride e-⋯M3+-PHY (M = Li, Na, and K). The differences in the static and dynamic first hyperpolarizability (ß0) values between them were also studied.

8.
Rapid Commun Mass Spectrom ; 35(11): e9089, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33759246

RESUMO

RATIONALE: Due to the ubiquity of fluorides and the small gap between a safe dose and a harmful one, it is necessary to develop a robust analytical method for determination of fluoride ions in various water samples with complex matrices. METHODS: Silylation of the fluoride ion was carried out by treatment with hydrochloric acid and phenyldimethylchlorosilane at room temperature. The formed phenyldimethylfluorosilane was detected by gas chromatography/mass spectrometry (GC/MS). RESULTS: Under the optimized conditions, linearity in the analytical method ranged from 0.050 to 5.0 µg/mL for the fluoride ion with R2 >0.9999. Reasonable reproducibility was obtained with the intraday relative standard deviation (RSD) (N = 5) of 2.04% and interday RSD (N = 5) of 3.75% at the concentration of 0.10 µg/mL. The developed method has been successfully applied to determine the fluoride ion in real water samples, including waste water samples, with the recovery between 81.12% and 113.04%. CONCLUSIONS: A robust method for the determination of the fluoride ion has been developed by silylation with phenyldimethylchlorosilane and GC/MS analysis. The established method showed good anti-interference and precision, and it has been applied for determination of the fluoride ion in various water samples.

9.
J Gastroenterol Hepatol ; 36(6): 1714-1720, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33150986

RESUMO

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) accounts for about 90% of pancreatic cancer, which is one of the most aggressive malignant neoplasms with a 9.3% five-year survival rate. The pathological biopsy is the current golden standard for confirming suspicious lesions of PDAC, but it is not entirely reliable because of the insufficient sampling amount and inaccurate sampling location. Therefore, developing a robust signature to aid the accurate diagnosis of PDAC is critical. METHODS: Based on the within-sample relative expression orderings of gene pairs, we identified a qualitative signature to discriminate both PDAC and adjacent samples from both chronic pancreatitis and normal samples in the training datasets and validated it in other independent datasets produced by different laboratories with different measuring platforms. RESULTS: A six-gene-pair signature was identified in the training data and validated in eight independent datasets. For surgical samples, 96.63% of 356 PDAC tissues, 100% of 11 pancreatitis tissues of non-cancer patients, and 23 of 24 normal pancreatic tissues were correctly classified. Especially, 59 of 60 cancer-adjacent normal tissues of PDAC patients were correctly identified as PDAC. For biopsy samples, all of 11 PDAC biopsy tissues were correctly classified as PDAC. CONCLUSION: The signature can distinguish both PDAC and PDAC-adjacent normal tissues from both chronic pancreatitis and normal tissues of non-cancer patients even when the sampling locations are inaccurate, which can aid the diagnosis of PDAC.


Assuntos
Biópsia/métodos , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/genética , Técnicas de Diagnóstico do Sistema Digestório , Perfilação da Expressão Gênica/métodos , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Manejo de Espécimes/métodos , Transcriptoma , Carcinoma Ductal Pancreático/patologia , Conjuntos de Dados como Assunto , Diagnóstico Diferencial , Humanos , Neoplasias Pancreáticas/patologia
10.
J Gastroenterol Hepatol ; 36(9): 2501-2512, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33565610

RESUMO

BACKGROUND AND AIM: Metastasis is the leading cause of recurrence in gastric cancer. However, the imaging techniques and pathological examinations for tumor metastasis have a high false-positive rate or a high false-negative rate, and many proposed that metastasis-related molecular biomarkers can hardly be validated in independent datasets. METHODS: We propose to use significantly stable gene pairs with reversal relative expression orderings (REOs) between non-metastasis and metastasis gastric cancer samples as the metastasis-related gene pairs. Based on the REOs of these gene pairs, we developed a qualitative transcriptional signature for predicting the recurrence risk of stages II-III gastric cancer patients after surgical resection. RESULTS: A REOs-based signature, consisting of 19 gene pairs (19-GPS), was selected from 77 stages II-III gastric cancer patients and validated in two independent datasets. Samples in the high-risk group had shorter disease-free survival time and overall survival time than those in the low-risk group. Differentially expressed genes (DEGs) between the high- and low-risk groups classified by 19-GPS were highly reproducible comparing with those between lymph node metastasis and lymph node non-metastasis groups. Functional enrichment analysis showed that these DEGs were significantly enriched in metastasis-related pathways, such as PI3K-Akt and Rap1 signaling pathways. The multi-omics analyses suggested that the epigenetic and genomic features might cause transcriptional differences between two subgroups, which help to characterize the mechanism of gastric cancer metastasis. CONCLUSIONS: The signature could robustly identify patients at high recurrence risk after resection surgery, and the multi-omics analyses might aid in revealing the metastasis-related characteristics of gastric cancer.


Assuntos
Neoplasias Gástricas , Intervalo Livre de Doença , Genômica , Humanos , Fosfatidilinositol 3-Quinases , Neoplasias Gástricas/genética , Neoplasias Gástricas/cirurgia
11.
J Sep Sci ; 44(14): 2856-2861, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33973713

RESUMO

Phytic acid, the principal storage form of phosphorus in wheat, plays both beneficial and antinutrient functions for human being, and its analytical method still needs further development. In this work, we have developed a new method for the determination of phytic acid in wheat products based on derivatization with (trimethylsilyl)diazomethane in combination with liquid chromatography-mass spectrometry analysis. Methyl esterification greatly decreased the polarity and the acidity of phytic acid, and thus the corresponding derivative can be easily analyzed by liquid chromatography-mass spectrometry under common conditions. Furthermore, treatment with cation exchange resin removed the polyvalent metal ions in the solutions, and thus derivatization of phytic acid can be achieved efficiently and completely. The standard curve for phytic acid has been well established in the linear range of 0.5-100 ng/mL with squared correlation coefficient more than 0.999 and the quantification limit of 0.25 ng/mL. The phytic acid content varies greatly in different wheat products, ranging from 153.5 to 17299.0 µg/g.


Assuntos
Ácido Fítico/análise , Triticum/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Esterificação , Fósforo/análise , Extração em Fase Sólida , Espectrometria de Massas em Tandem/métodos
12.
Rapid Commun Mass Spectrom ; 34(19): e8866, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32559337

RESUMO

RATIONALE: In general, ionization of analytes in atmospheric pressure ionization mass spectrometry (API-MS) in positive ion mode results in the formation of protonated molecules ([M + H]+ ) and/or cationized molecules (e.g., [M + Na]+ ). The formation of specific [M - H]+ cations in the API process is of significant interest for further investigation. METHODS: The ionization processes of 2-(diphenylsilyl)-1-phenyl-cyclopropanecarboxylate esters were investigated using electrospray ionization (ESI)-MS and atmospheric pressure chemical ionization-MS in positive ion mode. Theoretical calculations were carried out with the Gaussian 03 program using the density functional theory (DFT) method at the B3LYP/6-311 + G(2d,p) level. RESULTS: The anomalous [M - H]+ ion and the regular [M + Na]+ ion were both observed using ESI-MS. Interestingly, no [M + H]+ ion was obtained in the ESI-MS analysis, and acidification of the ESI solvent accelerated the formation of [M - H]+ rather than [M + H]+ ion. DFT calculations for the typical methyl 2-(diphenylsilyl)-1-phenyl-cyclopropanecarboxylate (1) indicated that the [1 + H]+ ion can thermodynamically and kinetically undergo facile H2 elimination to generate [1 - H]+ . CONCLUSIONS: The favorable formation of [M - H]+ ions in these compounds is attributed to the unique diphenylhydrosilyl group in their structure. The [M + H]+ ion formed easily underwent H2 elimination to produce the [1 - H]+ ion in the API source, and thus, acidification of the ESI solvent apparently accelerates the formation of the [1 - H]+ ion.

13.
Rapid Commun Mass Spectrom ; 34(3): e8576, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31498942

RESUMO

RATIONALE: m-Cresol is listed as a priority controlled contaminant in many countries, but it is very difficult to accurately determine isomeric cresols due to their incomplete chromatographic separation on commercially available chromatographic columns and their nearly identical mass spectra. METHODS: Silylation of isomeric cresols was carried out by treatment with N-methyl-N-(trimethylsilyl)trifluoroacetamide. The formed trimethyl(tolyloxy)silanes were analyzed by gas chromatography/mass spectrometry (GC/MS). Theoretical calculations were carried out with the Gaussian 03 program using the density functional theory (DFT) method at the B3LYP/6-311 + G(2d,p) level. RESULTS: The derivatives of three isomeric cresols and six isomeric xylenols have been completely separated on an HP-5MS capillary column within a GC run of only 10 minutes. In addition, the derivative o-cresol can be very easily differentiated from its isomers due to its characteristic base peak ion at m/z 91 in electron ionization (EI)-MS. DFT calculation results indicated that the formation of the abundant fragment ion at m/z 91 is attributed to a facile dissociation pathway involving the shift of a neighboring phenylmethyl hydrogen atom in EI-MS of trimethyl(o-tolyloxy)silane. CONCLUSIONS: Silylation provides a promising solution for simultaneous determination of isomeric cresols and isomeric xylenols.

14.
Liver Int ; 38(10): 1812-1819, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29682909

RESUMO

BACKGROUND & AIMS: Currently, using biopsy specimens to confirm suspicious liver lesions of early hepatocellular carcinoma are not entirely reliable because of insufficient sampling amount and inaccurate sampling location. It is necessary to develop a signature to aid early hepatocellular carcinoma diagnosis using biopsy specimens even when the sampling location is inaccurate. METHODS: Based on the within-sample relative expression orderings of gene pairs, we identified a simple qualitative signature to distinguish both hepatocellular carcinoma and adjacent non-tumour tissues from cirrhosis tissues of non-hepatocellular carcinoma patients. RESULTS: A signature consisting of 19 gene pairs was identified in the training data sets and validated in 2 large collections of samples from biopsy and surgical resection specimens. For biopsy specimens, 95.7% of 141 hepatocellular carcinoma tissues and all (100%) of 108 cirrhosis tissues of non-hepatocellular carcinoma patients were correctly classified. Especially, all (100%) of 60 hepatocellular carcinoma adjacent normal tissues and 77.5% of 80 hepatocellular carcinoma adjacent cirrhosis tissues were classified to hepatocellular carcinoma. For surgical resection specimens, 99.7% of 733 hepatocellular carcinoma specimens were correctly classified to hepatocellular carcinoma, while 96.1% of 254 hepatocellular carcinoma adjacent cirrhosis tissues and 95.9% of 538 hepatocellular carcinoma adjacent normal tissues were classified to hepatocellular carcinoma. In contrast, 17.0% of 47 cirrhosis from non-hepatocellular carcinoma patients waiting for liver transplantation were classified to hepatocellular carcinoma, indicating that some patients with long-lasting cirrhosis could have already gained hepatocellular carcinoma characteristics. CONCLUSIONS: The signature can distinguish both hepatocellular carcinoma tissues and tumour-adjacent tissues from cirrhosis tissues of non-hepatocellular carcinoma patients even using inaccurately sampled biopsy specimens, which can aid early diagnosis of hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular/genética , Diagnóstico Precoce , Neoplasias Hepáticas/genética , Fígado/patologia , Transcriptoma , Biópsia , Carcinoma Hepatocelular/diagnóstico , Humanos , Cirrose Hepática/complicações , Neoplasias Hepáticas/diagnóstico , Transplante de Fígado , Curva ROC , Listas de Espera
15.
Rapid Commun Mass Spectrom ; 32(4): 342-348, 2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-29226511

RESUMO

RATIONALE: Carcinogenic o-methylaniline is one of the banned aromatic amines in azo dyes, but it is very difficult to distinguish it from its noncarcinogenic isomers due to their identical retention time on chromatography and similar mass spectra. METHODS: Imidization of the isomeric methylanilines was carried out by treatment with benzaldehyde under mild conditions. The formed derivatives were analyzed by gas chromatography/mass spectrometry (GC/MS). Theoretical calculations were carried out on the Gaussian 03 program by using the density functional theory method at the B3LYP/6-311+G(d,p) level. RESULTS: Imidization of methylanilines occurred easily and gave rise to the corresponding N-methylbenzylidene benzenamines. The isomeric derivatives were completely separated by GC, and thus the three isomeric methylanilines could be determined simultaneously. Due to the ortho effect, the derivative from o-methylaniline has a characteristic fragment ion at m/z 118 with a stable bicyclic structure, and it could be easily differentiated from the meta- and para-isomers in electron ionization mass spectrometry. CONCLUSIONS: These results provided a promising solution for simultaneous determination of isomeric methylanilines.

16.
Conserv Biol ; 32(2): 376-389, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29077226

RESUMO

The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species-specific basis. Species-specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999-2001. We randomly selected and genetically identified fin trimmings (n = 4800), produced during fin processing, from the retail market of Hong Kong in 2014-2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one-third of identified species are threatened with extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1-64.2% for blue [Prionace glauca], 0.2-1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, and the most common species in trade, the blue shark, was not among them. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals.


Assuntos
Tubarões , Animais , Teorema de Bayes , China , Conservação dos Recursos Naturais , Hong Kong , Masculino , Inquéritos e Questionários
17.
ScientificWorldJournal ; 2014: 894346, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25386622

RESUMO

We give the simple general principle of studying the relations among fuzzy t-filters on residuated lattices. Using the general principle, we can easily determine the relations among fuzzy t-filters on different logical algebras.


Assuntos
Lógica Fuzzy , Modelos Teóricos , Reconhecimento Automatizado de Padrão , Algoritmos
18.
Sci Total Environ ; 939: 173592, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-38810745

RESUMO

This study provides a comprehensive analysis of the vacuum drying process for sludge drying, with a focus on optimizing energy efficiency and emission control. The study used both lab-scale static and pilot-scale vacuum drying systems to test various parameters like vacuum levels, heat source temperatures, and sludge thicknesses. The results indicated that optimal drying conditions were achieved at a vacuum level of -0.06 MPa, a heat temperature of 140 °C, and a sludge thickness of 3.4 mm, where the drying rate reaches 0.13278 g·g-1·min-1. The study underscores the significant influence of vacuum level, temperature, and sludge thickness on drying rates. The Page model was used to analyze drying kinetics, elucidating how changes in these parameters affect drying characteristics. Furthermore, the study also examined the pollutant emissions and energy efficiency at the pilot scale. It found that high vacuum environments could efficiently dry sludge using low-temperature heat source, leading to average energy consumption per unit evaporation of 3020.29 kJ/kg, which is lower compared to traditional methods. By harnessing low-grade industrial waste heat, this can be further reduced to 875.76 kJ/kg. This study offers valuable insights for sustainable sludge management systems, highlighting the environmental and economic benefits of vacuum drying technology. The detailed experimental approach and thorough analysis make a significant contribution to the field of the sludge drying.

19.
Polymers (Basel) ; 16(10)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38794526

RESUMO

In this paper, the solid-state shear milling (S3M) strategy featuring a very strong three-dimensional shear stress field was adopted to prepare the high-performance polyoxymethylene (POM)/molybdenum disulfide (MoS2) functional nanocomposite. The transmission electron microscope and Raman measurement results confirmed that the bulk MoS2 particle was successfully exfoliated into few-layer MoS2 nanoplatelets by the above simple S3M physical method. The polarized optical microscope (PLM) observation indicated the pan-milled nanoscale MoS2 particles presented a better dispersion performance in the POM matrix. The results of the tribological test indicated that the incorporation of MoS2 could substantially improve the wear resistance performance of POM. Moreover, the pan-milled exfoliated MoS2 nanosheets could further substantially decrease the friction coefficient of POM. Scanning electron microscope observations on the worn scar revealed the tribological mechanism of the POM/MoS2 nanocomposite prepared by solid-state shear milling. The tensile test results showed that the pan-milled POM/MoS2 nanocomposite has much higher elongation at break than the conventionally melt-compounded material. The solid-state shear milling strategy shows a promising prospect in the preparation of functional nanocomposite with excellent comprehensive performance at a large scale.

20.
J Proteome Res ; 12(6): 2422-38, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-23607740

RESUMO

Sexual dimorphism is initialed by the components of the sex determination pathway and is most evident in gonads and germ cells. Although striking dimorphic expressions have been detected at the transcriptional level between the silkworm larval testis and the ovary, the sex-dimorphic expressions at the protein level have not yet been well characterized. The proteome of silkworm larval gonads was investigated using a shotgun-based identification. A total of 286 and 205 nonredundant proteins were identified from the silkworm testis and ovary, respectively, with a false discovery rate (FDR) lower than 1%. Only 40 and 16 proteins were previously identified, and 246 and 189 proteins were newly identified in the silkworm testis and the ovary, respectively. The gametogenesis mechanism of silkworm was demonstrated using the protein expression profile and bioinformatics analysis. Cellular retinoic acid binding protein (CRABP) showed to be highly abundant in testis, while tubulins were abundant in ovary. Several homologies of Drosophila essential proteins for gametogenesis were identified in silkworm, such as male meiotic arrest gene product ALY and VISMAY in testis, and maternal mRNA localization protein exuperantia and SQUID in ovary. The gene ontology (GO) annotation and pathway analysis provide system-level insights into the sexual dimorphism and gametogenesis.


Assuntos
Bombyx/genética , Gametogênese/genética , Proteínas de Insetos/isolamento & purificação , Ovário/química , Proteoma/isolamento & purificação , Testículo/química , Animais , Mapeamento Cromossômico , Cromossomos de Insetos/química , Drosophila melanogaster/genética , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Proteínas de Insetos/química , Proteínas de Insetos/genética , Larva/genética , Masculino , Anotação de Sequência Molecular , Proteoma/química , Proteoma/genética , Homologia de Sequência de Aminoácidos , Caracteres Sexuais
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