Ancient genome of the Chinese Emperor Wu of Northern Zhou.

Emperor Wu (, Wudi) of the Xianbei-led Northern Zhou dynasty, named Yuwen Yong (, 543-578 CE), was a highly influential emperor who reformed the system of regional troops, pacified the Turks, and unified the northern part of the country. His genetic profile and physical characteristics, including his appearance and potential diseases, have garnered significant interest from the academic community and the public. In this study, we have successfully generated a 0.343×-coverage genome of Wudi with 1,011,419 single-nucleotide polymorphisms (SNPs) on the 1240k panel. By analyzing pigmentation-relevant SNPs and conducting cranial CT-based facial reconstruction, we have determined that Wudi possessed a typical East or Northeast Asian appearance. Furthermore, pathogenic SNPs suggest Wudi faced an increased susceptibility to certain diseases, such as stroke. Wudi shared the closest genetic relationship with ancient Khitan and Heishui Mohe samples and modern Daur and Mongolian populations but also showed additional affinity with Yellow River (YR) farmers. We estimated that Wudi derived 61% of his ancestry from ancient Northeast Asians (ANAs) and nearly one-third from YR farmer-related groups. This can likely be attributed to continuous intermarriage between Xianbei royal families, and local Han aristocrats.1,2 Furthermore, our study has revealed genetic diversities among available ancient Xianbei individuals from different regions, suggesting that the formation of the Xianbei was a dynamic process influenced by admixture with surrounding populations.

Effects of the Omicron variant of coronavirus disease 2019 on anaemia treatment for patients undergoing peritoneal dialysis.

AIM: Patients undergoing dialysis are at high risk for coronavirus disease 2019 (COVID-19). Haemoglobin (Hb) levels may be changed in patients infected with the Omicron variant of COVID-19 who are undergoing peritoneal dialysis (PD). Therefore, we aimed to explore the effect of anti-anaemia treatment on such patients. METHODS: This study enrolled patients undergoing PD who were infected with the Omicron variant of COVID-19 at our centre between November 2022 and February 2023. We retrospectively analysed changes in Hb levels and explored the effectiveness of roxadustat and recombinant human erythropoietin (rhEPO) for patients infected with the Omicron variant of COVID-19. RESULTS: Among 125 enrolled patients, 83 (66.4%) were infected with the Omicron variant and 75 (90.4%) patients mainly experienced mild or moderate disease. During infection, C-reactive protein (CRP) levels were higher than those before infection (p < .001). Additionally, their CRP levels were negatively correlated with Hb levels (p = .002). However, Hb levels were decreased 1 month after infection (109.61 ± 10.64 g/L vs. 115.69 ± 12.04 g/L; p < .001). The roxadustat treatment group did not exhibit significantly decreased Hb levels 1 month after infection (114.57 ± 14.11 vs. 117.51 ± 10.74 g/L; p = .225). Conversely, the rhEPO treatment group experienced a mild decrease in Hb levels (108.69 ± 11.20 vs. 115.03 ± 12.23 g/L; p = .001). Ferritin levels increased in both groups during infection (p = .495). Two months after infection, ferritin levels (median, 205.0 ng/mL) were significantly decreased compared with during infection (median, 377.4 ng/mL) (p < .001) in the roxadustat treatment group. CONCLUSION: Roxadustat was effective than rhEPO for treating anaemia in patients undergoing PD who were infected with the Omicron variant of COVID-19.

Conscious sedation anesthesia using different doses of remifentanil combined with dexmedetomidine for peritoneal dialysis catheter implantation.

BACKGROUND: Conscious sedation anesthesia (CSA) is an anesthetic method during peritoneal dialysis catheter implantation. However, lack of optimal CSA strategies for patients with end-stage renal disease (ESRD). This study aimed to evaluate the analgesic effects and safety of CSA using different doses of remifentanil combined with dexmedetomidine during peritoneal dialysis catheter insertion. METHODS: Patients who underwent peritoneal dialysis (PD) catheter placement via open surgical incision were retrospectively analyzed and divided into three groups based on the tertile dose of remifentanil. The bispectral index (BIS) was used to monitor the depth of anesthesia. Data regarding clinical findings, the effects of anesthesia, and the incidence of drug-related adverse effects were collected. RESULTS: In total, 102 patients completed the surgery successfully and safely. The dose of remifentanil was 0.02-0.07 µg/kg/min, 0.08-0.13 µg/kg/min, and 0.14-0.20 µg/kg/min in Groups A, B, and C, respectively. Only seven patients reported mild pain during the surgery. No significant differences were observed among the numeric rating scale scores of the three groups (p > 0.05). Intraoperative hemodynamics were stable. The incidence of respiratory depression was 8.3%, 20.0%, and 41.9% in Groups A, B, and C, respectively (p < 0.01). The incidence of gastrointestinal symptoms in Group C (51.6%) was higher than that in Groups A and B (p < 0.05). CONCLUSION: Low-dose remifentanil (0.02-0.07 µg/kg/min) combined with dexmedetomidine achieved satisfactory anesthetic effects with fewer adverse drug reactions during PD catheter implantation, indicating its potential for use in patients undergoing PD catheter placement.

Evaluation of a two-test strategy for HIV screening in a low-prevalence setting and the indications for optimizing clinical management.

Objectives: To evaluate a two-test strategy for HIV screening in the low-prevalence population and to assess the feasibility of utilizing the optimal signal-to-cutoff (S/CO) threshold on the chemiluminescence immunoassay(CMIA) and an additional rapid test on the gold immune-chromatography assay (GICA) for screening positive patients and optimization of clinical management. Methods: We conducted a retrospective study of samples analyzed by the fourth-generation Architect HIV Ag/Ab combo assay (CMIA) in a large medical center between June 2017 and August 2020. Reactive samples underwent a second screening test using the rapid test GICA, followed by Western blot (WB) as the confirmatory test. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal S/CO. We calculated sensitivity, specificity, and predictive value based on our population. The performance of the single-test strategy (CMIA) was compared with that of the two-test strategy (CMIA and GICA). Logistic regression was used to analyze the factors of clinical characteristics leading to false positive results. Results: A total of 220558 samples were screened by CMIA, and 429 patients met the inclusion criteria. Of these, CMIA produced 199 false-positive results with a median S/CO of 1.93(IQR1.45-3.68) and 230 positive results with a median S/CO of 455.1 (IQR169.3-709.7). The optimal S/CO of the single-test strategy was 8.82, which achieved a sensitivity of 100% and a positive predictive value (PPV) of 90.9%. The two-test strategy (CMIA and GICA) provided a sensitivity of 100% and a PPV of 98.7%, which best correlated with the confirmatory test WB. The combination of S/CO 8.82 on the CMIA assay and additional test results of GICA can be defined as four types used to interpret HIV serostatus. The false positive rate (FPR) was high in the female, the age≤18 group, the pre-operative patients, and the patients from the clinical departments of Pediatrics, Gynecology and Obstetrics, and Oncology, etc. Conclusions: The false positive rate is high in the low-prevalence setting by using CMIA. The two-test strategy (CMIA and GICA) is recommended for HIV screening in hospitals. Hopefully, the clinicians will be able to interpret HIV serostatus and facilitate clinical decision-making while waiting for the confirmatory results.

Mitogenome analysis reveals predominantly ancient Yellow River origin of population inhabiting Datong agro-pastoral ecotone along Great Wall.

The Datong Basin was an important arena for population movement and admixture between the Yellow River Valley and Eastern Steppe. In historical materials, the region was often the setting for a tug-of-war between Han farmers and non-Han nomads. The genetic makeup and population history of this Datong population has, however, remained uncertain. In this study, we analysed 289 mitogenomes from Datong individuals. Our primary findings were: (1) population summary statistics analysis revealed a high level of genetic diversity and strong signals of population expansion in the Datong population; (2) inter-population comparisons (PCA and Fst heatmap) exhibited a close clustering between the Datong population and Northern Han, especially northern frontier groups, such as the Inner Mongolia Han, Heilongjiang Han, Liaoning Han and Tianjin Han; (3) phylogeographic analysis of complete mitogenomes revealed the presence of different components in the maternal gene pools of Datong population-the northern East Asian component was dominant (66.44%), whereas the southern East Asians were the second largest component with 31.49%. We also observed a much reduced west Eurasian (2.07%) component; (4) direct comparisons with ancient groups showed closer relationship between Datong and Yellow River farmers than Eastern Steppe nomads. Despite, therefore, centuries of Eastern Steppe nomadic control over the Datong area, Yellow River farmers had a much more significant impact on the Datong population.

Wind Turbine Condition Monitoring Using the SSA-Optimized Self-Attention BiLSTM Network and Changepoint Detection Algorithm.

Condition-monitoring and anomaly-detection methods used for the assessment of wind turbines are key to reducing operation and maintenance (O&M) cost and improving their reliability. In this study, based on the sparrow search algorithm (SSA), bidirectional long short-term memory networks with a self-attention mechanism (SABiLSTM), and a binary segmentation changepoint detection algorithm (BinSegCPD), a condition-monitoring method (SSA-SABiLSTM-BinSegCPD, SSD) used for wind turbines is proposed. Specifically, the self-attention mechanism, which can mine the nonlinear dynamic characteristics and spatial-temporal features inherent in the SCADA time series, was introduced into a two-layer BiLSTM network to establish a normal-behavior model for wind turbine key components. Then, as a result of the advantages of searching precision and convergence rate methods, the sparrow search algorithm was employed to optimize the constructed SABiLSTM model. Moreover, the BinSegCPD algorithm was applied to the predicted residual sequence to achieve the automatic identification of deterioration conditions for wind turbines. Case studies conducted on multiple wind turbines located in south China showed that the established SSA-SABiLSTM model was superior to other contrast models, achieving a better prediction precision in terms of RMSE, MAE, MAPE, and R2. The MAE, RMSE, and MAPE of SSA-SABiLSTM were 0.2543 °C, 0.3412 °C, and 0.0069, which were 47.23%, 42.19%, and 53.38% lower than those of SABiLSTM, respectively. The R2 of SABiLSTM was 0.9731, which was 4.6% higher than that of SABiLSTM. The proposed SSD method can detect deterioration conditions 47-120 h in advance and trigger fault alarm signals approximately 36 h ahead of the actual failure time.

Preoperative bowel preparation promotes intestinal functional recovery after esophagectomy.

Background: Patients are prone to intestinal dysfunction after esophagectomy. The value of preoperative bowel preparation before esophagectomy is controversial. There is a lack of evidence as to whether preoperative bowel preparation can help patients improve bowel function and shorten the recovery time of bowel function. Objectives: The objectives of this study were to explore whether preoperative bowel preparation can promote the recovery of intestinal function after esophagectomy. Methods: We analysed 139 patients who underwent elective radical esophagectomy in the Department of Thoracic Surgery at the Second Affiliated Hospital of Xi'an Jiaotong University from May 2016 to December 2018. The enrolled patients were divided into the study group (bowel preparation group) and the control group (no bowel preparation group) of 71 cases and 68 cases. Patients in the study group were given dissolved polyethylene glycol electrolyte powder and a cleansing enema the day before surgery. Patients in the control group were neither given polyethylene glycol electrolyte powder nor cleansing enemas before surgery. The postoperative recovery of the two groups were compared. Results: Postoperative bed rest time, bowel function recovery time and the time of first flatus and defecation after surgery were significantly shorter in patients with bowel preparation than in those without bowel preparation, and the differences were statistically significant. (P=0.038, P<0.001, P<0.001, P<0.001; respectively). Conclusions: Preoperative bowel preparation can promote the recovery of patients with esophageal cancer, especially the recovery of bowel function, which can reduce the pain caused by abdominal distension and improve the quality of life of patients.

Cultural and demic co-diffusion of Tubo Empire on Tibetan Plateau.

A high point of Tibetan Plateau (TP) civilization, the expansive Tubo Empire (618-842 AD) wielded great influence across ancient western China. However, whether the Tubo expansion was cultural or demic remains unclear due to sparse ancient DNA sampling. Here, we reported ten ancient genomes at 0.017- to 0.867-fold coverages from the Dulan site with typical Tubo archaeological culture dating to 1308-1130 BP. Nine individuals from three different grave types have close relationship with previously reported ancient highlanders from the southwestern Himalayas and modern core-Tibetan populations. A Dulan-related Tubo ancestry contributed overwhelmingly (95%-100%) to the formation of modern Tibetans. A genetic outlier with dominant Eurasian steppe-related ancestry suggesting a potential population movement into the Tubo-controlled regions from Central Asia. Together with archeological evidence from burial styles and customs, our study suggested the impact of the Tubo empire on the northeast edge of the TP involved both cultural and demic diffusion.

Parental Psychological Flexibility and Children's Behavior Problems in Rural Areas in Northeast China: The Mediation of Children's Emotion Regulation.

Children's behavior problems are not conducive to their sustainable development. Therefore, it is of great value to explore the mechanism of relevant influencing factors on the behavior problems of rural preschoolers. This study aimed to reveal the direct effect of parental psychological flexibility on children's behavior problems and the mediating effect of children's emotion regulation. Based on simple random sampling, 355 caregivers (male = 31.25 years, SD = 9.78; 74.08% females; 9.01% bachelor degree) were recruited from eight rural kindergartens in three provinces in northeast China. With questionnaires, caregivers reported their parental psychological flexibility and assessed their children's emotion regulation and behavior problems. SPSS 25.0 software was used for statistical data analysis. The results support our hypotheses, suggesting that parental psychological flexibility, emotional stability, and emotional regulation negatively predicted children's externalizing and internalizing behavior problems. Meanwhile, emotional stability and regulation partially mediated the relationship between parental psychological flexibility and children's externalizing and internalizing behavior problems. These findings provide a new perspective for preventing and intervening in preschoolers' behavior problems.

Construction of a ferroptosis-related eight gene signature for predicting the prognosis and immune infiltration of thyroid cancer.

Background: Thyroid cancer is the most common malignant tumor of the endocrine system. Most patients with thyroid cancer have a good prognosis, although a small proportion experience recurrence and metastasis and have a poor prognosis. Ferroptosis is a novel form of regulated cell death (RCD); previous studies have confirmed that ferroptosis was associated with thyroid cancer. The purpose of this study was to investigate the key ferroptosis-related genes in thyroid cancer and their relationship with prognosis and immune cell infiltration. Methods: In this study, 497 thyroid cancer RNA expression datasets were downloaded from the cancer genome atlas (TCGA) cohort and a prognostic risk model for eight ferroptosis-related genes (FRGs) was constructed by Lasso-Cox regression. The prognostic value of the risk model and the correlation of prognostic features with immune scores and tumor immune cell infiltration were systematically analyzed. Results: The prognostic risk model for eight FRGs (DPP4, TYRO3, TIMP1, CDKN2A, SNCA, NR4A1, IL-6 and FABP4) were constructed and validated in training and testing cohorts. Kaplan-Meier curve and receiver operating characteristic (ROC) curve analysis confirmed that that the ferroptosis-related eight gene signature had good predictive value for the prognosis of thyroid cancer (THCA) patients. Multivariate regression analysis further showed that the risk score of the prognostic model could be used as an independent prognostic factor for THCA patients. Functional enrichment analysis showed that DEGs in high risk and low risk groups were involved in immune-related biological processes and that there were significant differences in immune cell infiltration between the two risk groups. Conclusion: We identified eight key genes related to ferroptosis in THCA patients. Further studies are now needed to investigate the mechanisms involved; these genes may represent clinical diagnostic and prognostic biomarkers.

A prognostic model for cervical cancer based on ferroptosis-related genes.

Background: Ferroptosis is widely involved in the occurrence and development of various cancers, but a specific mechanism involving ferroptosis in cervical cancer is still unclear. Methods: Based on the expressions of ferroptosis-related genes, a prognostic model was constructed using lasso regression, and the overall predictive performance of this model was verified. An in-depth analysis of the prognostic model was then conducted. Results: The prognostic model showed good predictive performance in both the validation and test sets. Mechanism analysis indicated that differences in the tumor microenvironment were the basis of the predictive ability of the model. Notably, CA9 mRNA was significantly overexpressed in cervical carcinoma, tissues but not in normal cervix tissues. A pair of ceRNAs (CA9/ULBP2) could be involved in the carcinogenesis and development of cervical cancer, and the potential target might be hsa-miR-34a. In addition, predicted miRNAs and drugs for these DEGs were identified. Conclusions: We constructed a prognostic model with good predictive performance, based on the expression of ferroptosis-related genes. Further research found that the ceRNA pairs of ULBP2/CA9 could regulate cervical cancer through hsa-miR-34a. These results identified the mechanism of ferroptosis in cervical cancer, and might provide novel therapeutics for cervical cancer patients.

Research Progress of Ferroptosis in Adiposity-Based Chronic Disease (ABCD).

Ferroptosis is a multistep regulated cell death process induced by iron accumulation and lipid peroxidation. Classical GPX4-dependent pathway and GPX4-independent pathways can independently and synergistically inhibit ferroptosis and jointly maintain the oxidative balance of the body. WHO defines obesity as "a condition of abnormal or excessive fat accumulation in adipose tissue, to the extent that health may be impaired," and obesity is also defined as an adiposity-based chronic disease (ABCD). Obesity is a systemic disease that leads to metabolic abnormalities in various systems, resulting in a series of complications including obesity cardiomyopathy, atherosclerosis, nonalcoholic fatty liver disease, and diabetes mellitus. Emerging evidence shows that ferroptosis is closely associated with the occurrence and progression of various diseases. In recent years, ferroptosis has been found to play critical roles in obesity and its complications. This review discusses the mechanisms of how ferroptosis is initiated and controlled and discusses the research progress of ferroptosis in obesity and its complications.

Comparative Performance of the MGISEQ-2000 and Illumina X-Ten Sequencing Platforms for Paleogenomics.

The MGISEQ-2000 sequencer is widely used in various omics studies, but the performance of this platform for paleogenomics has not been evaluated. We here compare the performance of MGISEQ-2000 with the Illumina X-Ten on ancient human DNA using four samples from 1750BCE to 60CE. We found there were only slight differences between the two platforms in most parameters (duplication rate, sequencing bias, θ, δS, and λ). MGISEQ-2000 performed well on endogenous rate and library complexity although X-Ten had a higher average base quality and lower error rate. Our results suggest that MGISEQ-2000 and X-Ten have comparable performance, and MGISEQ-2000 can be an alternative platform for paleogenomics sequencing.

[Application of bundle management strategy in early mobility of mechanically ventilated patients].

OBJECTIVE: To explore the effect of bundle management strategy in early mobility of patients with mechanical ventilation. METHODS: Seventy-two mechanically ventilated patients admitted to the respiratory intensive care unit (RICU) of Fenyang Hospital of Shanxi Province from December 2019 to June 2020 were enrolled. The patients were divided into routine nursing control group (routine control group) and early mobility bundle management group (bundle group), with 36 cases in each group. The routine control group received regular nursing, including monitoring vital signs, raising the head of the bed, turning over and buttoning the back every 2 hours, daily awakening, airway humidification, prevention of digestive tract ulcer, analgesia and sedation management, prevention of deep vein embolism, pipeline management, regular monitoring of blood gas analysis and electrolytes according to the changes of the condition, prevention of aspiration, prevention of bacterial colonization, correct hand hygiene, and so on. The bundle group implemented the cluster early mobility strategy based on routine nursing. Firstly, set up a professional team to execute the standards. The team determined the plan and implemented the 4-level mobility plan, companied with psychological intervention, decided the termination standard and quality control. The incidence of intensive care unit acquired weakness (ICU-AW), ventilator-associated pneumonia (VAP), delirium, the duration of mechanical ventilation and the length of intensive care unit (ICU) stay were evaluated. RESULTS: Compared with the routine control group, the incidences of ICU-AW, VAP, and delirium in the bundle group were significantly lower (the incidence of ICU-AW: 36.11% vs. 69.44%, χ2 = 8.025, P = 0.005; the incidence of VAP: 8.33% vs. 30.56%, χ2 = 5.675, P = 0.017; the incidence of delirium: 5.56% vs. 36.11%, χ2 = 10.180, P = 0.001), the duration of mechanical ventilation was significantly shorter (days: 7.13±1.34 vs. 10.46±1.48, t = -10.145, P < 0.001), and the length of ICU stay was also significantly decreased (days: 9.03±2.43 vs. 13.06±3.63, t = -5.535, P < 0.001). CONCLUSIONS: The implementation of bundle management strategy of early mobility can promote the rehabilitation of mechanical ventilated patients, improve the prognosis and the quality of life. The effect is noticeable and it is worth popularizing.

Epidemiology and Risk Factors for Carbapenem-Resistant Klebsiella Pneumoniae and Subsequent MALDI-TOF MS as a Tool to Cluster KPC-2-Producing Klebsiella Pneumoniae, a Retrospective Study.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) appeared recently and now presents a particularly critical problem to hospitalized patients worldwide. We aim to investigate the epidemiology and the risk factors for CRKP colonization and infections, and to evaluate the application performance of MALDI-TOF MS in clustering CRKP. Results: CRKP colonization and infections incidence was 2.7 (35/1,319,427) per 100,000 patient-days. Inpatients in CRKP group had higher medical expense than CSKP group. Inpatients with underlying conditions, particularly with pulmonary diseases, and with antimicrobial use prior to culture within 30 days, especially with carbapenem use, were risk factors for CRKP acquisition. All CRKP isolates were detected producing KPC-2. The MALDI-TOF MS system and PFGE system provided similar results, with a good concordance between the two methods (adjusted Rand's coefficient, 0.846) and a high probability of MALDI-TOF MS to predict PFGE results (Wallace coefficient, 0.908). Conclusions: Underlying conditions, particularly pulmonary diseases, and antimicrobial use prior to culture within 30 days, especially carbapenem use, are risk factors for CRKP acquisition. BlaKPC-2 is the mainstream gene of CRKP in our geographic area of analysis. As only simple sample preparation is needed and the results can be obtained in a short time, MALDI-TOF MS may be considered a probable alternative to PFGE in clustering KPC-2-producing CRKP.

Correlation analysis between filamentous fungi and chemical compositions in a pu-erh type tea after a long-term storage.

Storage environment caused the difference between Jinhua Pu-erh tea (JPT) and General Pu-erh tea. In this study, fungal flora and chemical compositions were analyzed. The results showed that storage environment caused significant (p < .05) differences of theaflavins (TF), theabrownins (TB), tea polyphenols (TP), and water-soluble sugars (WSS), and a highly significant (p < .01) difference of thearubigins (TR). Aspergillus niger, Aspergillus pallidofulvus, Aspergillus sesamicola, Penicillium manginii, and Aspergillus tamarii were isolated from Pu-erh teas and identified based on colony characteristics and ITS, ß-tubulin, and calmodulin gene sequences, respectively. A. pallidofulvus, A. sesamicola, and P. manginii were dominant fungi in JPT and generated macroscopic yellow cleistothecia after a long-term storage. Correlation analysis showed that dominant fungi exhibited significantly (p < .05 or p < .01) positive or negative corrections with TF, TB, TP, WSS, TR, and gallic acid. This study revealed dominant fungi including A. pallidofulvus, A. sesamicola, and P. manginii and their effects on given chemical compositions.

LC-MS/MS-based metabolomic analysis of caffeine-degrading fungus Aspergillus sydowii during tea fermentation.

Natural microorganisms involved in solid-state fermentation (SSF) of Pu-erh tea have a significant impact on its chemical components. Aspergillus sydowii is a fungus with a high caffeine-degrading capacity. In this work, A. sydowii was inoculated into sun-dried green tea leaves for SSF. Metabolomic analysis was carried out by using UPLC-QTOF-MS method, and caffeine and related demethylated products were determined by HPLC. The results showed that A. sydowii had a significant (P < 0.05) impact on amino acids, carbohydrates, flavonoids, and caffeine metabolism. Moreover, A. sydowii could promote the production of ketoprofen, baclofen, and tolbutamide. Along with caffeine degradation, theophylline, 3-methylxanthine, 1,7-dimethylxanthine, 1-methylxanthine, and 7-methylxanthine were increased significantly (P < 0.05) during inoculated fermentation, which showed that demethylation was the main pathway of caffeine degradation in A. sydowii secondary metabolism. The absolute quantification analysis showed that caffeine could be demethylated and converted to theophylline and 3-methylxanthine. Particularly, about 93.24% of degraded caffeine was converted to theophylline, 27.92 mg/g of theophylline was produced after fermentation. PRACTICAL APPLICATION: Aspergillus sydowii could cause caffeine degradation in Pu-erh tea solid-state fermentation and produce theophylline through the demethylation route. Using a starter strain to ferment tea leaves offers a more controllable, reproducible, and highly productive alternative for the biosynthesis of theophylline.

Production of theophylline via aerobic fermentation of pu-erh tea using tea-derived fungi.

BACKGROUND: Caffeine is one of the most abundant methylxanthines in tea, and it remains stable in processing of general teas. In the secondary metabolism of microorganism, theophylline is the main conversion product in caffeine catabolism through demethylation. Microorganisms, involved in the solid-state fermentation of pu-erh tea, have a certain impact on caffeine level. Inoculating an appropriate starter strain that is able to convert caffeine to theophylline would be an alternative way to obtain theophylline in tea. The purpose of this study was to isolate and identify the effective strain converting caffeine to theophylline in pu-erh tea, and discuss the optimal conditions for theophylline production. RESULTS: Caffeine content was decreased significantly (p < 0.05) and theophylline content was increased significantly (p < 0.05) during the aerobic fermentation of pu-erh tea. Five dominant fungi were isolated from the aerobic fermentation and identified as Aspergillus niger, Aspergillus sydowii, Aspergillus pallidofulvus, Aspergillus sesamicola and Penicillium mangini, respectively. Especially, A. pallidofulvus, A. sesamicola and P. mangini were detected in pu-erh tea for the first time. All isolates except A. sydowii TET-2, enhanced caffeine content and had no significant influence on theophylline content. In the aerobic fermentation of A. sydowii TET-2, 28.8 mg/g of caffeine was degraded, 93.18% of degraded caffeine was converted to theophylline, and 24.60 mg/g of theophylline was produced. A. sydowii PET-2 could convert caffeine to theophylline significantly, and had application potential in the production of theophylline. The optimum conditions of theophylline production in the aerobic fermentation were 1) initial moisture content of 35% (w/w), 2) inoculation quantity of 8%, and 3) incubation temperature at 35 °C. CONCLUSIONS: For the first time, we find that A. sydowii PET-2 could convert caffeine to theophylline, and has the potential value in theophylline production through aerobic fermentation.

Bullying victimization and depression among left-behind children in rural China: Roles of self-compassion and hope.

BACKGROUND: Bullying victimization among school-aged children is an important public health issue that may affect their well-being and mental health. However, few studies have been conducted on left-behind children in rural China, who are defined as the children who stay in rural areas for more than six months and have one or both parents migrating to urban areas for work. The mechanisms through which bullying victimization will influence depression have disproportionally adopted a psychopathological perspective, and the protective factors are understudied. OBJECTIVE: This study aims at investigating the factors that might contribute to breaking up the vicious circle between bullying victimization and developmental problems, focusing on the protective role of self-compassion and hope in the association between bullying victimization and depression. METHODS: Using questionnaires, data were collected from a sample of 1091 school-aged left-behind children from west and central China. RESULTS: Compared with rural children living with their parents, left-behind children reported a higher level of bullying victimization. Bullying victimization was positively associated with depression through decreased self-compassion and hope, and self- compassion played a more crucial role than hope in the linkage between bullying victimization and depression. CONCLUSIONS: Our study's findings suggest that it is necessary to incorporate self-compassion and hope in mental health prevention and intervention programs targeting left-behind children with bullying victimization experiences.

[Determination of neohesperidin dihydrochalcone and naringin dihydrochalcone in feeds by solid phase extraction-high performance liquid chromatography].

A new method was established for the determination of neohesperidin dihydrochalcone (NHDC) and naringin dihydrochalcone (Naringin DC) in feeds by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The samples were extracted by methanol and were purified on an HLB solid-phase extraction column. Chromatographic separation was achieved on an XB-C18 column (150 mm×4.6 mm, 5 µm) by linear gradient elution using methanol/water as the mobile phase. The analytes were detected by the diode array detector (DAD). The results revealed a good linear correlation (r>0.999) between the peak areas and mass concentrations of dihydrochalcone sweeteners in the range of 0.2-49.0 mg/L. The limits of quantification (LOQs) of NHDC and Naringin DC were 0.02 and 0.01 mg/kg, respectively. Intra- and inter-day reproducibilities were 0.7%-4.1% and 0.9%-6.0%, respectively. The spiked recoveries for the samples and relative standard deviations (RSDs) were 86.2%-105.0% and 1.0%-6.3% (n=3), respectively. It is both sensitive and repeatable for the quantitative determination of neohesperidin dihydrochalcone and naringin dihydrochalcone in feeds, and thus, can be used to effectively reduce interference in feeds.