Metabolomic insights into the browning inhibition of fresh-cut apple by hydrogen sulfide.

Hydrogen sulfide (H2S) is known to effectively inhibit the browning of fresh-cut apples, but the mechanism at a metabolic level remains unclear. Herein, non-targeted metabolomics was used to analyze metabolic changes in surface and internal tissues of fresh-cut apple after H2S treatment. The results showed that prenol lipids were the most up-accumulated differential metabolites in both surface and inner tissue of fresh-cut apple during browning process, which significantly down-accumulated by H2S treatment. H2S treatment reduced the consumption of amino acid in surface tissue. Regarding inner tissue, H2S activated defense response through accumulation of lysophospholipid signaling and induced the biosynthesis of phenolic compounds. We therefore propose that H2S inhibited the surface browning of fresh-cut apple by reducing the accumulation of prenol lipids, directly delaying amino acid consumption in surface tissue and indirectly regulating defense response in inner tissue, which provides fundamental insights into browning inhibition mechanisms by H2S.

Diffuse uterine leiomyomatosis: A case report and review of literature.

BACKGROUND: Diffuse uterine leiomyomatosis (DUL) is a benign uterine smooth muscle neoplasm with unknown etiology. Since DUL is rarely reported, knowledge regarding it is limited. The rate of early diagnosis is low, and DUL is often misdiagnosed as common multiple uterine leiomyomas before surgery. CASE SUMMARY: A 27-year-old patient with no sexual activity presented to the Emergency Department of our hospital complaining of heavy vaginal bleeding. She had a history of uterine fibroids and menorrhagia. Pelvic examination showed a regularly enlarged uterus, similar in size to that associated with a 4-mo pregnancy. Pelvic magnetic resonance imaging (MRI) revealed numerous multiple uterine fibroids, and a transabdominal myomectomy (TM) was performed. Intraoperative exploration revealed that the myometrium was full of myoma nodules of variable sizes. Over 50 leiomyomas were removed. The pathology report confirmed leiomyoma. The patient was discharged and received a gonadotropin-releasing hormone analog (3.75 mg) for 6 mo. Ten months after surgery, the patient presented to the hospital again for abnormal uterine bleeding. MRI showed an irregular mass with a diameter of 5.2 cm without sharp demarcation in the uterine cavity. Submucosal leiomyoma was considered first, and the patient underwent a hysteroscopic myomectomy plus hymen repair. Intraoperative exploration showed that there were several leiomyomatosis masses in the cavity. Postoperative pathological examination confirmed submucosal leiomyoma and necrotic and generative tissue. Although the menstrual cycle was still irregular, the patient did not have symptoms of menorrhagia for a period of 28 mo after the second surgery. CONCLUSION: Individuals with DUL are easily misdiagnosed due to the lack of specific manifestations of this disease. MRI is helpful for early identification and preoperative evaluation. There is currently no unified method of diagnosis. For women who want to preserve fertility, conservative surgery should be made an option. When TM is chosen, a modified new myomectomy should be considered to avoid the drawbacks of traditional TM.

Atmospheric fate of peroxyacetyl nitrate in suburban Hong Kong and its impact on local ozone pollution.

Peroxyacetyl nitrate (PAN) is an important reservoir of atmospheric nitrogen, modulating reactive nitrogen cycle and ozone (O3) formation. To understand the origins of PAN, a field measurement was conducted at Tung Chung site (TC) in suburban Hong Kong from October to November 2016. The average level of PAN was 0.63 ±â€¯0.05 ppbv, with a maximum of 7.30 ppbv. Higher PAN/O3 ratio (0.043-0.058) was captured on episodes, i.e. when hourly maximum O3 exceeded 80 ppbv, than on non-episodes (0.01), since O3 production was less efficient than PAN when there was an elevation of precursors (i.e. volatile organic compounds (VOCs) and nitrogen oxide (NOx)). Model simulations revealed that oxidations of acetaldehyde (65.3 ±â€¯2.3%), methylglyoxal (MGLY, 12.7 ±â€¯1.2%) and other oxygenated VOCs (OVOCs) (8.0 ±â€¯0.6%), and radical cycling (12.2 ±â€¯0.8%) were the major production pathways of peroxyacetyl (PA) radical, while local PAN formation was controlled by both VOCs and nitrogen dioxide (NO2). Among all VOC species, carbonyls made the highest contribution (59%) to PAN formation, followed by aromatics (26%) and biogenic VOCs (BVOCs) (10%) through direct oxidation/decomposition. Besides, active VOCs (i.e. carbonyls, aromatics, BVOCs and alkenes/alkynes) could stimulate hydroxyl (OH) production, thus indirectly facilitating the PAN formation. Apart from primary emissions, carbonyls were also generated from oxidation of first-generation precursors, i.e., hydrocarbons, of which xylenes contributed the most to PAN production. Furthermore, PAN formation suppressed local O3 formation at a rate of 2.84 ppbv/ppbv, when NO2, OH and hydroperoxy (HO2) levels decreased and nitrogen monoxide (NO) value enhanced. Namely, O3 was reduced by 2.84 ppbv per ppbv PAN formation. Net O3 production rate was weakened (∼36%) due to PAN photochemistry, so as each individual production and loss pathway. The findings advanced our knowledge of atmospheric PAN and its impact on O3 production.

Optimization of Liquid Fermentation Conditions and Protein Nutrition Evaluation of Mycelium from the Caterpillar Medicinal Mushroom, Cordyceps militaris (Ascomycetes).

Cordyceps militaris is a well-known traditional Chinese medicinal mushroom. In this study, the mycelium of C. militaris was cultured using liquid fermentation technology and the culture medium components were optimized by the orthogonal test method. Our results showed that the optimal medium combination for the mycelium growth is 3% glucose, 3% peptone, 0.1% MgSO4, and 0.2% KH2PO4 The international general nutritional assessment method was applied to the overall evaluation of the protein nutrition value of submerged cultivated mycelium and fruit body of C. militaris. The protein contents in C. militaris mycelium and fruit body are 21.10% and 18.47%, respectively. The first limiting amino acids of C. militaris mycelium and fruit bodies are the sulfur-containing amino acids (methionine and cysteine), and the second limiting amino acid is isoleucine. The quality of amino acids from submerged cultivated mycelium and fruit body from C. militaris was also evaluated by amino acid score (AAS), chemical score (CS), essential amino acid index (EAAI), biological value (BV), nutritional index (NI), and score of ratio coefficient of amino acid (SRCAA). Our data demonstrate that AAS, CS, EAAI, BV, NI, and SRCAA scores of the submerged cultivated mycelium proteins are 62.41, 38.74, 88.37, 84.63, 18.61, and 25.57, respectively, whereas the fruit body proteins are 37.11, 34.59, 61.92, 55.79, 11.44, and 68.51, respectively. The protein content of C. militaris mycelium has higher nutrition value than that of fruit body protein, which holds the promise for future further development. Our study provides the optimal culture conditions and the essential nutritional information of medicinal species, C. militaris.

Myocardial protection of early extracorporeal membrane oxygenation (ECMO) support for acute myocardial infarction with cardiogenic shock in pigs.

The aim of this study was to explore myocardial protection of early extracorporeal membrane oxygenation (ECMO) support for acute myocardial infarction with cardiogenic shock in pigs. 24 male pigs (34.6 ± 1.3 kg) were randomly divided into three groups-control group, drug therapy group, and ECMO group. Myocardial infarction model was created in drug therapy group and ECMO group by ligating coronary artery. When cardiogenic shock occurred, drugs were given in drug therapy group and ECMO began to work in ECMO group. The pigs were killed 24 h after cardiogenic shock. Compared with in drug therapy group, left ventricular end-diastolic pressure in ECMO group decreased significantly 6 h after ligation (P < 0.05). At the end of the experiments, LV - dp/dt among three groups was significantly different, drug therapy group < ECMO group < control group. There was no difference in LV + dp/dt between drug therapy group and ECMO group. Compared with drug group, myocardial infarct size of ECMO group did not reduce significantly, but myocardial enzyme and troponin-I decreased significantly. Compared with drug therapy, ECMO improves left ventricular diastolic function, and may improve systolic function. ECMO cannot reduce myocardial infarct size without revascularization, but may have positive effects on ischemic areas by avoiding further injuring.