Changes of Volatile Organic Compounds of Different Flesh Texture Pears during Shelf Life Based on Headspace Solid-Phase Microextraction with Gas Chromatography-Mass Spectrometry

Aroma is an important sensory factor in evaluating the quality of pear fruits. This study used headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) to analyze the volatile organic compounds (VOCs) of three crispy pears and five soft pears during shelf life, and the changes in soluble solids content (SSC) were analyzed. The results showed that the SSC of the soft pears such as Nanguoli, Jingbaili and Louis was always higher than that of the crispy pears throughout shelf life. A total of 160 VOCs were detected in the eight pear varieties. Orthogonal partial least squares discriminant analysis (OPLS-DA) and hierarchical cluster analysis (HCA) combined with predictor variable importance projection (VIP) showed that the eight pear varieties could be obviously classified into six groups according to the differences in their VOCs, and 31 differential VOCs were screened out, which could be used to differentiate between pears with different flesh textures. The results of clustering heat map analysis showed that, with the extension of shelf life, the content of each different VOC did not change much in crispy pears, whereas the difference in soft pears was larger. This study confirmed the potential of determining the optimal shelf life of different pear varieties about aroma evaluation and studying the mechanism of differences in VOCs in the future.

Interdigitation of Radiation Earlier in the Multimodal Treatment of Patients with Lymphoma: The Effect on Opiate Analgesic Requirements

PURPOSE/OBJECTIVE(S)

Delay in radiation therapy (RT) as part of multimodality therapy in Hodgkin (HL) and non-Hodgkin lymphoma (NHL) is associated with worse pain scores. In a heterogeneous cohort of lymphoma patients, we hypothesize that interdigitating RT before fewer (versus more) lines of chemotherapy (C) will be associated with lower opiate analgesic requirement.

MATERIALS/METHODS

From 2009-2019, patients with HL or NHL received palliative (36.5%) or definitive (63.3%) RT at a single institution. An IRB approved database with baseline treatment/disease characteristics, including oral morphine equivalent (OME) requirement, was reviewed. OME was recorded for a) 3-month period prior to RT, b) the month during RT, and c) 3 months after RT. Post-RT change in OME was calculated as the difference in "b" and "c" such that greater or less OME use post-RT was defined as positive or negative value respectively. We performed one-tailed t-test analyses to determine differences in OME during RT between different cohorts. Correlations between baseline characteristics and OME were performed using Spearman correlations, controlling for lymphoma subtype, stage, tumor volume, relapsed/refractory disease, duration of radiation and bulky disease.

RESULTS

Of 180 patients, 57.8% had NHL, 40.6% were stage IV and 29.4% had bulky disease. At median of 19 days [6-80] from diagnosis, 74% of patients received C with a median of 2 lines [1-4] before RT. The median interval from diagnosis to RT was 11 months [4-36]. Pearson correlation showed a negative association between time from diagnosis to RT and postRT OME in the definitive cohort (R2 = 0.42, F = 4.54, p = 0.002) such that the longer the time to RT, the larger the decrease in OME postRT as compared to during RT. T-test showed higher mean OME during RT for those receiving > 2 lines of C preRT (148.3mg) as compared to those receiving ≤ 2 lines before RT (51.5mg, p = 0.02). In patients receiving definitive RT, the difference remained significant: those receiving >2 lines of C had higher OME during RT as compared to those receiving ≤ 2 lines (207.5mg versus 48.3mg, p = 0.02). The difference in mean OME for patients receiving >2 C lines versus ≤ 2 lines was not significantly different in the palliative cohort (75.6 vs 60.6, p = 0.33). OME use during RT was also found to be higher in patients with bulky disease as compared to non-bulky disease (175.7 versus 52.0, p = 0.04).

CONCLUSION

In our single-center experience, patients who received >2 lines of C prior to RT were found to have a significantly higher mean OME requirement during RT. In patients receiving definitive RT, longer time to receipt of RT was found to be associated with a larger decrease in OME post-RT, likely related to starting with a higher OME. Interdigitation of RT early on, prior to the 3rd line of chemotherapy, may help reduce pain and improve quality of life.

Could immune-related hepatitis rapidly progress to immune-related cirrhosis?

BACKGROUND

Immune-related hepatitis is one of the prevalent adverse events associated with immunotherapy, especially immune checkpoint inhibitors (ICIs). For patients without a history of liver disease, autoimmune disease, or alcohol consumption, it is not clear whether immune-related hepatitis could rapid progress to immune-related cirrhosis.

CASE REPORT

We report the case of a 54-year-old female with stage IIIB primary pulmonary lymphoepithelioma-like carcinoma (PLELC) diagnosed with immune-related hepatitis. After 15 months, a liver biopsy demonstrated the rapid progression of liver cirrhosis although systematic corticosteroid administration.

CONCLUSIONS

Long-term immune activation caused by ICIs may exacerbate the process of cirrhosis. Great attention should be paid to the rapid progression to liver cirrhosis of immune-related hepatitis in the clinic.

Genome-wide association study for reproduction-related traits in Chinese domestic goose

1. This study measured six reproduction traits in a Sichuan white goose population (209 individuals), including fertility, qualified egg rate, plasma concentrations of progesterone (P), follicle-stimulating hormone (FSH), prolactin (PRL) and oestrogen (E2).2. Whole-genome resequencing data from the same goose population (209 individuals) were used in a genome-wide association study (GWAS) utilising a mixed linear model to investigate the genes and genetic markers associated with reproduction traits. The frequency of the selected SNPs and haplotypes were determined using the Matrix-Assisted Laser Desorption Ionisation Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) method.3. In total, 42 SNPs significantly associated with these traits were identified. A haplotype block was constructed based on five SNPs that were significantly associated with qualified egg rate, with individuals having the haplotype CCTTAAGGAA having the lowest qualified egg rate.4. In conclusion, these results provided potential markers for marker-assisted selection to improve goose reproductive performance and a basis for elucidating the genetics of goose reproduction.

Monitoring Volatile Organic Compounds in Different Pear Cultivars during Storage Using HS-SPME with GC-MS

Aroma, which plays an essential role in food perception and acceptability, depends on various mixture of volatile organic compounds (VOCs). Meanwhile, as a field of metabolomics, VOC analysis is highly important for aroma improvement and discrimination purposes. In this work, VOCs in pear fruits were determined via headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) to study variations among different cultivars and storage stages. In 12 cultivars of pear fruits, a total of 121 VOCs were quantified, including 40 esters, 32 alcohols, 16 aldehydes, 13 alkenes, 11 ketones, 4 acids, and 5 other compounds. The types and amounts of VOCs in different cultivars varied dramatically, which were in the range of 13-71 and 3.63-55.65 mg/kg FW (fresh weight), respectively. The Dr. Guyot cultivar showed the highest level of VOCs, both in type and amount. After 21 days storage at 4 °C, total concentration of VOCs increased from initial levels of 50.76 to 101.33 mg/kg FW. Storage at 20 °C made a larger contribution to production for VOCs than that at 4 °C, resulting in the maximum content of VOCs (117.96 mg/kg FW) in fruit after 14 days storage at 4 °C plus 7 days at 20 °C. During storage, the content of esters showed a gradual increase, while the content of alcohols and aldehydes decreased. Based on the results presented, related alcohols were recognized as the intermediates of conversion from aldehydes to esters.

Whole-genome sequencing reveals breed-differential CNVs between Tongcheng and Large White pigs

Large phenotypic differences have been observed between Tongcheng and Large White pigs. However, little is known about their genetic basis. This study performed a genome-wide comparison of CNVs between Tongcheng and Large White pigs using genome sequencing data. By combining the advantages of three different strategies (read depth, paired-end mapping and split read), we detected in total 18 687 CNVs that covered approximately 3.5% of the pig genome length for Tongcheng and Large White pigs. We identified 1864 breed-stratified CNVs (top 10%) by performing V_ST statistics. Functional enrichment analyses for genes located in breed-stratified CNVs were found to be involved in pigmentation, behavior, immune system and reproductive processes, which coincide with phenotypic differences between the two breeds. Using a systematic analysis of the genome and transcriptome data, we further identified four novel breed-differential CNVs on the functional genes (disease-resistant, DCUN1D2 and SPARCL1; lipid metabolism, PLEKHA2 and SLCO1A2). Subsequent PCR validation confirmed their accurate breakpoint positions in 33 Tongcheng pigs and 33 Large White pigs. This study provides essential information on differential CNVs for further research on the genetic basis of phenotypic differences between Tongcheng and Large White pigs.

miR-152 promotes spinal cord injury recovery via c-jun amino terminal kinase pathway

OBJECTIVE

The aim of this research is to explore the possible role of miR-152 in spinal cord injury and its underlying mechanism.

MATERIALS AND METHODS

After a mouse model of spinal cord injury (SCI) was developed, Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was used to detect the expression of miR-152 and c-jun in the mouse. In addition, the expression levels of interleukin-1b (IL-1b), interleukin-18 (IL-18) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). Subsequently, miR-152 was overexpressed and the levels of inflammation and c-jun after spinal cord injury were detected by Western blot. Furthermore, the grip strength of double forelimb, left forelimb or right forelimb of the mice was detected using a grip force test after miR-152 was overexpressed in the injured area of each group.

RESULTS

By constructing a mouse model of spinal cord injury, we found that the expression of miR-152 in the injured area decreased with time; meanwhile, the inflammatory relative genes including IL-1b, IL18, TNF-α, and c-jun were significantly increased. However, miR-152 overexpression significantly reduced the levels of inflammation genes as well as the expression of c-jun. Besides, the strength of the forelimbs in the spinal cord injury mice was restored.

CONCLUSIONS

MiR-152 could inhibit inflammatory responses and promote the recovery of the spinal cord injury through the c-jun N-terminal kinase pathway and it can be a target molecular for treating spinal cord injury.

[Clinicopathological and molecular features of pulmonary enteric adenocarcinoma]

Objective: To investigate the clinicopathological and molecular characteristics of pulmonary enteric adenocarcinoma (PEAC). Methods: The clinical and pathological data of 19 cases of PEAC in the Affiliated Cancer Hospital of Zhengzhou University were retrospectively collected from 2015 to 2019. Immunohistochemistry (IHC) was used to detect the relevant immunophenotypes, amplification refractory mutation system (ARMS) and fluorescence in situ hybridization (FISH) were used to detect the expression of EGFR, KRAS and ALK genes. The patients were followed up, and the relevant literature was reviewed and analyzed. Results: There were 19 cases, including 10 males and 9 females, with a mean age of 58 years (range 33-71 years). Microscopically, the tumors showed moderately to highly differentiated adenoid and/or papillary growth patterns. The tumor cells were highly columnar and sometimes showed pseudostratification. Inflammatory necrosis and scattered nuclear fragmentation were seen in some glandular lumens. IHC showed variable expression of CK7 (19/19), TTF1 (8/19), Napsin A (6/19), villin (17/19), CK20 (16/19) and CDX2 (10/19). Molecular testing showed KRAS mutation in nine cases (9/19), EGFR mutation in one case (1/19), and positive ALK split signal in one case (1/19). In the literature, the reported mutation rate of KRAS in PEAC was much higher than that of EGFR and ALK. All 19 cases underwent surgical resection and 11 cases were subjected to chemotherapy or radiotherapy. Conclusions: PEAC is a rare variant of invasive pulmonary adenocarcinoma, and has similar histological and cytological features to that of colorectal adenocarcinoma. However, detailed medical history, histologic heterogeneity, an IHC combination of CK7(+)/villin(+) and high KRAS mutation rate are the key points of diagnosis. The prognosis needs long-term follow-up and big data statistics.

Molecular cloning of the goose GnRH gene and identification of GnRH polymorphisms associated with laying traits

1. Egg-laying traits are important economic characteristics in goose production (Anser cygnoides). The gene GnRH, which encodes gonadotropin-releasing hormone, is a strong candidate gene for egg-laying traits in avian species. 2. In this study, a 3520 bp genomic sequence and a 279 bp mRNA sequence for GnRH, which encoded 92 amino acids, were determined. The GnRH DNA sequence contains four exons and three introns, and the DNA and deduced amino acid sequences were highly conserved across mammals (human, macaque, cow, and sheep) and avians (chicken, fulmar and quail). 3. Using a direct sequencing method, 46 single nucleotide polymorphisms (SNPs) were identified in the GnRH genomic sequence that were shared between two Sichuan White goose populations (217 and 208 individuals). Furthermore, 44 haplotypes were constructed using a sliding window approach. Association analysis between the SNPs and haplotypes and egg-laying traits showed that 10 SNPs affected the first egg weight, average egg weight, egg number at 48 weeks and egg number at 64 weeks. 4. These results lay the foundation for further studies of the function of GnRH in geese and provide a theoretical basis for marker-assisted selection of egg-laying traits in the Sichuan white goose population.

HER2 exon 20 insertions in non-small-cell lung cancer are sensitive to the irreversible pan-HER receptor tyrosine kinase inhibitor pyrotinib

BACKGROUND

Effective targeted therapy for non-small-cell lung cancer (NSCLC) patients with human epidermal growth factor receptor 2 (HER2) mutations remains an unmet need. This study investigated the antitumor effect of an irreversible pan-HER receptor tyrosine kinase inhibitor, pyrotinib.

PATIENTS AND METHODS

Using patient-derived organoids and xenografts established from an HER2-A775_G776YVMA-inserted advanced lung adenocarcinoma patient sample, we investigated the antitumor activity of pyrotinib. Preliminary safety and efficacy of pyrotinib in 15 HER2-mutant NSCLC patients in a phase II clinical trial are also presented.

RESULTS

Pyrotinib showed significant growth inhibition of organoids relative to afatinib in vitro (P = 0.0038). In the PDX model, pyrotinib showed a superior antitumor effect than afatinib (P = 0.0471) and T-DM1 (P = 0.0138). Mice treated with pyrotinib displayed significant tumor burden reduction (mean tumor volume, -52.2%). In contrast, afatinib (25.4%) and T-DM1 (10.9%) showed no obvious reduction. Moreover, pyrotinib showed a robust ability to inhibit pHER2, pERK and pAkt. In the phase II cohort of 15 patients with HER2-mutant NSCLC, pyrotinib 400 mg resulted in a objective response rate of 53.3% and a median progression-free survival of 6.4 months.

CONCLUSION

Pyrotinib showed activity against NSCLC with HER2 exon 20 mutations in both patient-derived organoids and a PDX model. In the clinical trial, pyrotinib showed promising efficacy.

CLINICAL TRIAL REGISTRATION

NCT02535507.

The direct effects of gonadotropin-releasing hormone on proliferation of granulosa cells and development of follicles in goose

1. The study objectives were to determine the direct effects of gonadotropin-releasing hormone (GnRH) on the proliferation of ovarian granulosa cells (GCs) and the development of follicles in geese (Anser cygnoides) by colorimetry and ethynyl-2'-deoxyuridine (EdU) cell proliferation assays, in which primary GCs were treated with different concentrations of GnRH agonist (alarelin acetate) and an antagonist (cetrorelix acetate). Differently expressed genes (DEGs) were identified by RNA-sequencing and validated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting. 2. The EdU assays showed that the proliferation of GCs was affected by the GnRH agonist and antagonist in a dose-dependent manner. The effect of treatment on cell proliferation was statistically significant at the concentrations of 10^-5 mol/l alarelin and 1 mg/l cetrorelix acetate. A total of 134 DEGs (76 downregulated and 58 upregulated for alarelin treatment) and 226 DEGs (90 downregulated and 136 upregulated for cetrorelix) were identified by RNA-sequencing analysis, respectively. Enrichment analysis indicated that DEGs were enriched in the GO terms of cell-cell signalling and cell junctions. The pathways that regulate the development of follicles were identified, including the biological progress of cAMP accumulation, ovulation cycle and vasculature that are essential to follicular selection. 3. The results suggested that GnRH might directly regulate GC proliferation via autocrine or paracrine pathways related to cell junctions. In particular, it was confirmed that the mRNA and protein expression levels of the oestrogen receptor 2 (ESR2) gene, a negative transcription factor involved in follicular maturation and ovulation, were affected by GnRH agonist or antagonist in GCs. 4. In conclusion, GnRH might play an important role in follicular development by changing the expression of genes that participate in cAMP accumulation, ovulation cycle and cell junctions in ovarian GCs.

Absence of Quantum-Confined Stark Effect in GaN Quantum Disks Embedded in (Al,Ga)N Nanowires Grown by Molecular Beam Epitaxy

Several of the key issues of planar (Al,Ga)N-based deep-ultraviolet light-emitting diodes could potentially be overcome by utilizing nanowire heterostructures, exhibiting high structural perfection, and improved light extraction. Here, we study the spontaneous emission of GaN/(Al,Ga)N nanowire ensembles grown on Si(111) by plasma-assisted molecular beam epitaxy. The nanowires contain single GaN quantum disks embedded in long (Al,Ga)N nanowire segments essential for efficient light extraction. These quantum disks are found to exhibit intense light emission at unexpectedly high energies, namely, significantly above the GaN bandgap, and almost independent of the disk thickness. An in-depth investigation of the actual structure and composition of the nanowires reveals a spontaneously formed Al gradient both along and across the nanowire, resulting in a complex core/shell structure with an Al-deficient core and an Al-rich shell with continuously varying Al content along the entire length of the (Al,Ga)N segment. This compositional change along the nanowire growth axis induces a polarization doping of the shell that results in a degenerate electron gas in the disk, thus screening the built-in electric fields. The high carrier density not only results in the unexpectedly high transition energies but also in radiative lifetimes depending only weakly on temperature, leading to a comparatively high internal quantum efficiency of the GaN quantum disks up to room temperature.

Identification of new interferences leached from plastic microcentrifuge tubes in electrospray ionization mass spectrometry

RATIONALE

The incredible sensitivity of the modern mass spectrometry instrument enables scientists to detect a large number of molecules ranging from small organic compounds to biological macromolecules. However, the same sensitivity often throws up challenges with respect to background interferences and contaminants. The identification and source of these contaminants is very important for reducing background contamination and ensuring the accuracy of the analysis results.

METHODS

The interfering compounds were analyzed by high-performance liquid chromatography coupled with a hybrid quadrupole-orbitrap mass spectrometer. The structural analysis was conducted by obtaining the accurate masses of precursors and their fragment ions. The retention time and MS/MS spectrum of one of the interfering compounds (N-lauryldiethanolamine) were compared with an authentic standard to reach an unequivocal structural assignment.

RESULTS

The interferences (m/z 274 and 318 in positive mode) were observed during the analysis of herbicides in tea samples by electrospray ionization mass spectrometry (ESI-MS). Their structures were identified to be N-lauryldiethanolamine and N-(2-hydroxyethyl)-N-(2-(2-hydroxyethoxy)ethyl)dodecylamine by fragmentation interpretation and further confirmed by a standard compound. These interferences were found to be leached from the plastic microcentrifuge tubes used during sample pretreatment. The plastic tubes from two of the five suppliers tested were found to contain these two interferences.

CONCLUSIONS

In this work, we presented an example about the observation, identification and source of interferences in ESI-MS. The N-lauryldiethanolamine and other ethoxylated aliphatic alkylamines are common plastic antistatic agents. They possess high proton affinity so that they show a strong response in ESI positive mode. In order to avoid their interference during mass spectrometric analysis we need to choose plastic tubes (or other plastic materials) that do not contain such antistatic agents.

Interfacial reactions during the molecular beam epitaxy of GaN nanowires on Ti/Al2O3

We investigate the occurrence of interfacial reactions during the self-assembled formation of GaN nanowires on Ti/Al₂O₃(0001) substrates in plasma-assisted molecular beam epitaxy. The conditions typical for the synthesis of ensembles of long nanowires (>1 μm) are found to promote several chemical reactions. In particular, the high substrate temperature leads to the interdiffusion of Al and O at the Ti/Al₂O₃ interface resulting in the formation of Al _x Ti _y O_1-x-y and Ti _x O_1-x compounds. Furthermore, O is found to incorporate into the nanowires degrading their luminescence by heavy n-type doping. At the same time, impinging Ga and N species react with the substrate giving rise to the simultaneous formation of single-crystalline TiN and Ga _x Ti _y O_1-x-y compounds. The latter compounds tend to form hillocks at the substrate surface, on top of which nanowires elongate with large tilt angles with respect to the substrate normal. We develop here a specific process in order to mitigate the detrimental effects of these interfacial reactions, while maintaining the low areal density and absence of coalescence which is the strong asset of growing nanowires on Ti/Al₂O₃. We find that the combination of a thick Ti film with an intentional low temperature nitridation step preceding nanowire growth and a limited growth temperature results in ensembles of uncoalesced and well-oriented nanowires with luminescence properties comparable to those of standard GaN nanowires prepared on Si. All these properties, together with the inherent benefits of integrating semiconductors on metals, make the present materials combination a promising platform for the further development of group-III nitride nanowire-based devices.

A method based on precolumn derivatization and ultra high performance liquid chromatography with high-resolution mass spectrometry for the simultaneous determination of phthalimide and phthalic acid in tea

Phthalimide can be formed from either the degradation of folpet and phosmet, or reaction of phthalic anhydride with primary amino groups. Consequently, the sum of phthalimide and folpet, expressed as folpet-residue definition, is highly prone to false-positive levels of folpet in tea. An analytical method is thus urgently needed to investigate the residue level and source of phthalimide in tea. In this work, we developed an accurate method of determining phthalimide and phthalic acid (the indicator of phthalic anhydride) by acetonitrile extraction and 3-bromopropyltrimethylammonium bromide derivatization coupled with ultra high performance liquid chromatography and high-resolution mass spectrometry. The method was validated, and linearity (correlation coefficients > 0.99) was obtained. Satisfactory recoveries at 10, 20, 50, and 100 μg/kg ranged from 76 to 117%, and the intra- and interday accuracies were <23%. The limit of quantification for phthalimide and phthalic acid was 10 μg/kg. The developed method was further successfully used to determine phthalimide and phthalic acid in some tea samples. The positive rate of phthalimide and phthalic acid detected in the tea samples ranged from 30-75 and 50-90%, respectively.

[The analysis of the effect of psycho-intervention combined with diazepam on patients with sudden sensorineural hearing loss and anxiety]

Objective: To investigate the therapeutic effect of psychological intervention combined with diazepam on sudden hearing loss patients with anxiety. Method: 108 cases of sudden hearing loss patients with anxiety were randomly divided into two groups(n=54 in each group): The control group received routine treatment of sudden hearing loss, the study group was given psychological intervention combined with diazepam tablets(2.5 mg once, twice a day) based on the routine treatment. The hearing and HAMA and SAS scores were reviewed after 10 days of treatment. Result: After 10 days of treatment, the average hearing threshold of patients in the control group and the study group were respectively increased by （19.65±7.89）dB and （26.93±9.04）dB (t=4.54, P=0.006), the HAMA score of two groups were respectively decreased by 4.68 and 10.75（t=9.949, P=0.000）and the SAS score of two groups were respectively decreased by 15.93 and 23.39 (t=6.773, P=0.000), and the total efficiency of hearing of two groups were 61.11% and 77.78% (χ²=4.441, P=0.035),respectively. the differences were statistically significant. Conclusion: Psychological intervention combined with diazepam can relieve anxiety in patients with sudden hearing loss effectively, and play a positive role in the development and prognosis of patients with sudden sensorineural hearing loss.