Aroma profiles of green tea made with fresh tea leaves plucked in summer.

There is a claim that fresh tea leaves plucked in summer (FTL-S) are not suitable for green tea processing, but there is no scientific evidence to support this claim. The aroma properties of green tea (GT-S) made with FTL-S were studied by the analysis of volatiles during process, coupled with odor activity value (OAV) determination. The odor profiles of dry tea and tea infusion were investigated by sensory evaluation. The GT-S contained higher proportions of alcohols, alkenes and heterocyclic compounds with strong fragrance and nutty odors as well as moderate floral odor in comparison with FTL-S. ß-Damascenone and 2-ethyl-3,5-dimethylpyrazine with the OAV of 54,290 and 1.15, respectively, were the aroma-active compounds imparting woody and nutty odors in GT-S, respectively. Current study provides an alternative way to use FTL-S for green tea production, and we also found that L-theanine is an important aroma precursor for the formation of green tea aroma.

Effect of the roasting degree on flavor quality of large-leaf yellow tea.

Roasting is crucial for producing large-leaf yellow tea (LYT) as it substantially affects chemical composition and sensory quality. However, the effect of roasting degree on LYT flavor quality is not clear. To investigate the effect of roasting degree on LYT flavor, the odor profiles and sensory evaluations of LYTs produced with small fire, medium fire and old fire roasting (OF) were determined. The OF was essential for the formation of LYT flavor with strong roasted, nutty, woody odors and weak fatty, fruity odors, and retaining high levels of GCG, total volatiles and heterocyclic compounds. Furthermore, the characteristic crispy-rice-like odor was only found in LYT with OF treatment and burnt flavor was missing. 2,3-Diethyl-5-methylpyrazine, trans-ß-ionone with odor activity value above 1600 and 39 respectively offered roasted, floral odors, respectively in LYT. The current results provide a scientific basis for understanding the reactions that occur during the conventional production of LYT.

Changes of volatile compounds and odor profiles in Wuyi rock tea during processing.

Wuyi rock tea (WRT), is one kind of oolong tea and widely appreciated for its typical 'rock flavor'. The odor characteristics of WRT during processing were comprehensive investigated by gas chromatography-mass spectrometry, sensory evaluation and odor activity value (OAV). Alcohols, alkenes and esters were the main volatiles formed during tea processes, but the WRT contained more heterocyclic compounds, among which 15 N-containing volatiles were newly identified in this study, accounting for 60.52% of total amounts of volatiles in WRT. In response, the original green and chemical odors converted to roasted and woody odors, and full fire processing was effective to enhance roasted, floral and woody odors, weaken chemical odor. 2-Ethyl-3,5-dimethylpyrazine (OAV 4.71) was confirmed as the aroma-active compound of WRT with roasted odor by aroma recombination experiment. In addition, strong roasted, floral and moderate woody odors were perceived as the outline of 'rock flavor' in WRT aroma. These results provide theoretical basis for processing and quality control of WRT.

Aroma Characteristics of Lavender Extract and Essential Oil from Lavandula angustifolia Mill.

Lavender and its products have excellent flavor properties. However, most studies focus on the aroma profiles of lavender essential oil (LEO). The volatiles in lavender extracts (LEs), either in volatile compositions or their odor characteristics, have rarely been reported. In this study, the odor characteristics of LEs and LEO were comprehensively investigated by gas chromatography-mass spectrometry (GC-MS), coupled with sensory evaluation and principal chemical analysis (PCA). In addition, the extraction conditions of lavender extracts from inflorescences of Lavandula angustifolia Mill. were optimized. Under the optimal conditions of extraction, twice with 95% edible ethanol as the solvent, the LEs tended to contain the higher intensity of characteristic floral, herbal and clove-like odors as well as higher scores of overall assessment and higher amounts of linalool, linalool oxides I and II, linalyl acetate, lavandulyl acetate and total volatiles than LEO. PCA analysis showed that there were significant differences on the odor characteristics between LEO and LEs. The LEO, which was produced by steam distillation with a yield of 2.21%, had the lower intensity of floral, clove-like, medicine-like, pine-like and hay notes, a lower score of overall assessment and lower levels of linalool oxides I and II, linalyl acetate, lavandulyl acetate and total volatiles compared with LEs, whereas the relative contents of linalool and camphor in LEO were significantly higher than that in LEs. Furthermore, the earthy, green and watery odors were only found in LEO. Concerning the odor characteristics and volatile compositions, the LEs had better odor properties than LEO. These results provided a theoretical basis for the industrial preparation of lavender-related products.

Neurological manifestations of patients with COVID-19: potential routes of SARS-CoV-2 neuroinvasion from the periphery to the brain.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), has caused a global pandemic in only 3 months. In addition to major respiratory distress, characteristic neurological manifestations are also described, indicating that SARS-CoV-2 may be an underestimated opportunistic pathogen of the brain. Based on previous studies of neuroinvasive human respiratory coronaviruses, it is proposed that after physical contact with the nasal mucosa, laryngopharynx, trachea, lower respiratory tract, alveoli epithelium, or gastrointestinal mucosa, SARS-CoV-2 can induce intrinsic and innate immune responses in the host involving increased cytokine release, tissue damage, and high neurosusceptibility to COVID-19, especially in the hypoxic conditions caused by lung injury. In some immune-compromised individuals, the virus may invade the brain through multiple routes, such as the vasculature and peripheral nerves. Therefore, in addition to drug treatments, such as pharmaceuticals and traditional Chinese medicine, non-pharmaceutical precautions, including facemasks and hand hygiene, are critically important.

Controlled Synthesis of Tb3+/Eu3+ Co-Doped Gd2O3 Phosphors with Enhanced Red Emission.

(Gd0.93-xTb0.07Eux)2O3 (x = 0⁻0.10) phosphors shows great potential for applications in the lighting and display areas. (Gd0.93-xTb0.07Eux)2O3 phosphors with controlled morphology were prepared by a hydrothermal method, followed by calcination at 1100 °C. XRD, FE-SEM, PL/PLE, luminescent decay analysis and thermal stability have been performed to investigate the Eu3+ content and the effects of hydrothermal conditions on the phase variation, microstructure, luminescent properties and energy transfer. Optimum excitation wavelength at ~308 nm nanometer ascribed to the 4f8-4f75d¹ transition of Tb3+, the (Gd0.93-xTb0.07Eux)2O3 phosphors display both Tb3+and Eu3+ emission with the strongest emission band at ~611 nm. For increasing Eu3+ content, the Eu3+ emission intensity increased as well while the Tb3+ emission intensity decreased owing to Tb3+→Eu3+ energy transfer. The energy transfer efficiencies were calculated and the energy transfer mechanism was discussed in detail. The lifetime for both the Eu3+ and Tb3+ emission decreases with the Eu3+ addition, the former is due to the formation of resonant energy transfer net, and the latter is because of contribution by Tb3+→Eu3+ energy transfer. The phosphor morphology can be controlled by adjusting the hydrothermal condition (reaction pH), and the morphological influence to the luminescent properties (PL/PLE, decay lifetime, etc.) has been studied in detail.

Aroma compositions of large-leaf yellow tea and potential effect of theanine on volatile formation in tea.

Large-leaf yellow tea (LYT) imparting unique toasty flavor is a traditional beverage in China. The volatile composition of LYT after full fire processing (FF-YT) was determined by different extraction methods. Steam distillation (SD), solid-phase microextraction (SPME) and headspace (HS) were applied for analysis of tea body notes, tea infusion and dry tea aroma, respectively. A total of 143 volatile compounds was identified by the three methods, of which SD-FF-YT, SPME-FF-YT, and HS-FF-YT extracts contained 100, 72, and 56 volatiles, respectively. Heterocyclics and aromatic compounds were the main volatile composition of LYT and might be contributors to its crispy-rice-like odor. l-Theanine was demonstrated to contribute to the formation of tea volatiles. N-Ethylacetamide, formed in the l-theanine only model thermal reaction, was probably involved in the LYT volatile formation. The current results provide new insight into l-theanine on aroma formation, although the detailed formation mechanism remains largely unknown.

Contribution of l-theanine to the formation of 2,5-dimethylpyrazine, a key roasted peanutty flavor in Oolong tea during manufacturing processes.

l-Theanine, the most abundant amino acid in tea, is widely believed to be associated with the tea taste, however, its contribution to the formation of tea aroma is still unknown. Volatiles were determined and nitrogen-containing compounds formed during manufacturing processes were quantified. Lower levels of total sugar and l-theanine were detected in the Oolong tea product undergoing full fire processing (FFOT) suggesting that l-theanine probably involved in the volatile formation during manufacturing processes. Methylpyrazine and 2,5-dimethylpyrazine, two newly formed compounds in FFOT, together with other volatiles were successfully detected in a model thermal reaction of d-glucose and l-theanine (GT-MTR) but not detectable in thermal reactions with single d-glucose (G-MTR) or l-theanine (T-MTR). The concentration of 2,5-dimethylpyrazine increased significantly by adding additional l-theanine to 2nd roasted tea. Our study demonstrated that l-theanine, at least partly, contributed to the formation of 2,5-dimethylpyrazine, a key roasted peanutty flavor in Oolong tea.

Low-dose Simvastatin Increases Skeletal Muscle Sensitivity to Caffeine and Halothane.

Objective To determine whether the myotoxic side effects of statin simvastatin affect skeletal muscle's sensitivity to caffeine and halothane.Methods Primary cultured neonate rat skeletal myotubes were treated with 0.01-5.0 µmol/L simvastatin for 48 hours. MTT was used to evaluate cellular viability. The gross morphology and microstructure of the myotubes were observed with a light and electron microscope, respectively. The intracellular calcium concentrations ([Ca2+]i) at rest and in response to caffeine and halothane were investigated by fluorescence calcium imaging. Data were analyzed by analysis of variance (ANOVA) test.Results Simvastatin (0.01-5.0 µmol/L) decreased myotube viability, changed their morphological features and microstructure, and increased the resting [Ca2+]i in a dose-dependent manner. Simvastatin did not change myotube's sensitivity to low doses of caffeine (0.625-2.5 mmol/L) or halothane (1.0-5.0 mmol/L). In response to high-dose caffeine (10.0 mmol/L, 20.0 mmol/L) and halothane (20.0 mmol/L, 40.0 mmol/L), myotubes treated with 0.01 µmol/L simvastatin showed a significant increase in sensitivity, but those treated with 1.0 µmol/L and 5.0 µmol/L simvastatin showed a significant decrease. The sarcoplasmic reticulum Ca2+ storage peaked in the myotubes treated with 0.01 µmol/L simvastatin, but it decreased when cells were treated with higher doses of simvastatin (0.1-5.0 µmol/L).Conclusions The myotoxic side effect of simvastatin was found to change the sensitivity of myotubes in response to high-dose caffeine and halothane. When dose was low, sensitivity increased mainly because of increased Ca2+ content in the sarcoplasmic reticulum, which might explain why some individuals with statin-induced myotoxic symptoms may show positive caffeine-halothane contracture test results. However, when the dose was high and the damage to the myotubes was severer, sensitivity was lower. It is here supposed that the damage itself might put individuals with statin-induced myotoxic symptoms at greater risks of presenting with rhabdomyolysis during surgery or while under anesthesia.

Phospholipid transfer protein (PLTP) deficiency impaired blood-brain barrier integrity by increasing cerebrovascular oxidative stress.

Phospholipid transfer protein (PLTP) regulates lipid metabolism and plays an important role in oxidative stress. PLTP is highly expressed in blood-brain barrier (BBB), but the role of PLTP in BBB integrity is not clear. In this study, BBB permeability was detected with in vivo multiphoton imaging and Evans blue assay. We found that PLTP deficient mice exhibited increased BBB permeability, as well as decreased expression of tight junction proteins occludin, zona occludens-1 (ZO-1) and claudin-5 in brain vessels. Cerebrovascular oxidative stress increased in PLTP deficient mice, including increased levels of reactive oxygen species (ROS) and lipid peroxidation marker 4-hydroxy-2-nonenal (HNE) and reduced superoxide dismutase (SOD) activity. Dietary supplementation of antioxidant vitamin E increased BBB integrity and tight junction proteins expression via reducing cerebrovascular oxidative stress. These findings indicated an essential role of PLTP in maintaining BBB integrity, possibly through its ability to transfer vitamin E, and modulate cerebrovascular oxidative stress.

[A case of anesthesia for caesarean section in a late pregnant woman with recurrent femoral osteosarcoma].

Osteosarcoma is the most common malignant tumor primarily originated from bone, yet puerpera with osteosarcoma is exceedingly rare. We present here a case of a 27-year-old woman who was operated for femoral osteosarcoma 2 years ago. With emergency admission to Peking University Third Hospital she was diagnosed with recurrent osteosarcoma during the second trimester of pregnancy. As pregnancy might promote tumor development, the general principle demanded timely termination of pregnancy after diagnosis, but the patient insisted on giving up all her comprehensive cancer treatment. As a result, a well made plan for the protection of mother and child was carries out to perform cesarean delivery at the end of 32 weeks of gestation under general anesthesia. The baby was delivered successfully and the mother's condition was kept stable. This case highlighted the benefits of multidisciplinary cooperation and balanced the needs of the developing fetus with those of the mother.

Screening of differentially expressed genes in the hypothalamus of a rat neuropathic pain model following sciatic nerve injury.

BACKGROUND: Neuropathic pain is induced by injury or disease of the nervous system. Most studies have so far focused only on a few known molecules and signaling pathways among neurons. However, all signal transmissions involved in neuropathic pain appear to be an integral system at different molecular levels. This study was designed to screen the differentially expressed genes of the hypothalamus in chronic constriction injury (CCI) rats and analyze their functions in developing neuropathic pain. METHODS: Ten adult female Sprague-Dawley rats ((200 +/- 10) g) were used in experimental group and sham group (n = 5 in each group). Mechanical allodynia tests were performed to ensure that the CCI rat model was constructed successfully. Total hypothalamus RNAs were isolated from each group. Forward suppression subtractive hybridization (SSH) library of rat hypothalamus was constructed and up-regulated cDNA clones at neuropathic pain states were obtained via suppressed subtractive hybridization technique and the functions of these genes were analyzed bioinformatically. RESULTS: Mechanical allodynia tests showed that the experimental rats had a significantly reduced mechanical allodynia threshold 3 to 13 days after CCI vs sham surgery rats (P < 0.01), indicating that the model was successful. Forward SSH library of the rat hypothalamus was constructed successfully and 26 over-expressed expression sequence tags (ESTs) were obtained from these up-regulated cDNA clones. CONCLUSION: Twenty-six up-regulated genes, involved in the regulation of cell cycle and apoptosis, signal transduction, and neuroprotection, may play key roles in decreasing mechanical withdraw thresholds in CCI rats, which implicates a multidimensional and integrated molecular mechanism at gene level in developing neuropathic pain with the supraspinal contributions.

[Effect of intraoperative using cell saver on blood sparing and its impact on coagulation function].

OBJECTIVE: To observe the effectiveness of using cell saver (CS) during surgery on blood sparing and its impact on patient's hematology and coagulation function. METHODS: One-hundred and thirty-eight patients undergoing elective surgery were recruited for intraoperative blood salvage using CS. Blood routine, blood chemistry and coagulation function were measured before surgery, after infusion of salvaged blood and postoperative day 1, respectively. RESULTS: In total, 112,056 ml of packed red blood cells were collected, with a mean value of 812 ml per patient. The percentage of autologous blood transfusion volume to the total blood transfusion volume was from 48% to 89%. Allogenic blood transfusion rate was from 5% to 100%. Compared with the values before surgery, the hemoglobin concentration, platelet count, plasma total protein and fibrinogen concentration decreased significantly after the transfusion of salvaged blood and the first postoperative day (P < 0.05 or P < 0.01), while the prothrombin time was significantly prolonged (P < 0.05). CONCLUSIONS: The use of CS during surgery can, to a certain extent, reduce the requirement of allogenic blood. However, reinfusion of large amount of salvaged blood may affect coagulation function.

[Use of blood salvage machine in oncologic surgeries: a clinical observation of 13 cases].

OBJECTIVE: To evaluate the effects on blood sparing and risk of hematogenous tumor dissemination of the use of blood salvage machine in oncologic surgeries. METHODS: The clinical data of 13 patients, 6 with malignant tumors and 7 with benign tumors, who received the use of blood salvage machine during oncologic surgeries based on informed consent, were analyzed. RESULTS: In total 42,575 ml of packed red blood cells were collected during surgery with a mean value of 3 275 ml (400 - 1500 ml) per patient. The average amount of allogenic transfusion per patient was 1 530 ml (0 - 8,000 ml). The number of blood salvage machine use in oncologic surgeries accounted for 8.6% (13/152) of the total number of blood salvage machine use in surgeries in that period. The perioperative mortality rate of the oncologic surgeries with the use of blood salvage machine was 7.7% (1/13). The post-operative metastasis rate of liver and lung was 15.4% (2/13). CONCLUSION: The use of blood salvage machine during oncologic surgeries improves the blood sparing effect. However, it cannot be used routinely, since it may result in hematogenous tumor cell dissemination.

[Perioperative melatonin secretion rhyme in patients undergoing coronary artery bypass grafting surgery].

OBJECTIVE: To investigate perioperative patterns of melatonin and cortisol secretion rhyme in patients undergoing coronary artery bypass grafting surgery. METHODS: Eleven male patients scheduled for elective coronary artery bypass grafting surgery (CABG) under hypothermic cardiopulmonary bypass (CPB) were enrolled in the study. Anesthesia was induced and maintained with propofol (3 mg.kg-1.h-1) and supplemented with fentanyl (15 micrograms/kg). Blood samples were taken during surgery at specific time-points and every 3 h in the immediate postoperative period and postoperative day 2 and day 3. Plasma melatonin and cortisol levels were measured by radioimmunoassay and enzyme-linked immunosorbent assay respectively. RESULTS: During surgery, plasma melatonin levels were below the minimum sensitivity level but low levels, without circadian variation, were measured during the immediate postoperative period. During postoperative day 2 and day 3, circadian secretion patterns of melatonin were present in 10 patients and showed an inverse correlation with light intensity exposed (r = -0.480, P = 0.01). Plasma cortisol levels in the immediate postoperative period were significantly higher than those before induction of anesthesia (P < 0.01). During postoperative day 2 and day 3, only 3 patients regained circadian secretion of cortisol. CONCLUSIONS: It is concluded that melatonin and cortisol secretion are disrupted during cardiac surgery and in the immediate postoperative period.

Perioperative melatonin secretion in patients undergoing coronary artery bypass grafting.

UNLABELLED: Melatonin, a neurohormone, plays an important role in adjusting the "biological clock" in humans. We sought to describe perioperative patterns of melatonin secretion in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass (CPB). After IRB approval and written informed consent, 12 male patients scheduled for elective coronary artery bypass grafting under hypothermic CPB were enrolled in the study. During anesthesia, patients' eyes were carefully covered to prevent light effects. Blood samples were taken at specific time points during surgery, every 3 h in the immediate postoperative period, and for 24 h from 6:00 PM of Postoperative Day 2 until 6:00 PM of Postoperative Day 3. Plasma melatonin and cortisol concentrations were measured by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. During surgery, plasma melatonin concentrations were below the minimum sensitivity concentration, yet small concentrations, without circadian variation, were detected during the immediate postoperative period. During Postoperative Days 2 and 3, circadian secretion patterns of melatonin were present in 10 patients and showed an inverse correlation with light intensity (r = 0.480; P < 0.01). Plasma cortisol concentrations in the immediate postoperative period were significantly larger than those before the induction of anesthesia (P < 0.01). Only three patients regained circadian secretion of cortisol. We concluded that melatonin and cortisol secretion was disrupted during cardiac surgery with CPB and in the immediate postoperative period. However, circadian rhythms of melatonin were present in most patients from Postoperative Day 2. Only 30% of the patients regained circadian rhythm of cortisol secretion. IMPLICATIONS: Melatonin is a hormone that plays an important role in adjusting the biological clock in humans and that regulates secretion of various other hormones. We studied melatonin secretion in patients undergoing cardiac surgery with cardiopulmonary bypass. Melatonin secretion was disturbed during and immediately after surgery but had recovered a circadian rhythm 24 h later, raising the question of whether melatonin should be supplemented before cardiac surgery.