[System analysis of the ecological distribution of bacteriophages in hospital wastewater]

Phage therapy is one of the most important tools for the treatment of infections with multi-drug resistant bacteria. Such phages are usually isolated from hospital effluents, however, no systematic study on the distribution of phages in hospital effluents has been conducted so far. The aim of this study was to isolate the corresponding phages of common pathogenic bacteria isolated in the clinic as hosts, so as to assess the ecological distribution of phages in hospital wastewater and to provide a reference for the isolation and application of phages of drug-resistant bacteria in the clinic. A cross-sectional study design was used in this study. The 125 pathogenic bacteria (belonging to 16 different strains) isolated from the clinical microbiology laboratory of Qilu Hospital of Shandong University from May to June 2023 were selected as the target strains, and the phages corresponding to these strains were isolated and purified from the hospital wastewater by using the double-layer plate sandwich method. At the same time, the distribution of pathogenic bacteria in the same batch of wastewater was analyzed with the help of mNGS sequencing technology, so as to preliminarily investigate the abundance correspondence between pathogenic bacteria and phages in wastewater. The results showed that a total of 56 phage strains were isolated from 125 clinical pathogens as hosts, corresponding to six pathogens, including Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. All six pathogenic bacteria contained strains with different degrees of drug resistance, with a higher percentage of multi-drug resistant strains in A. baumannii, Escherichia coli and P. aeruginosa. The phage acquisition rates of these six pathogens were, in descending order, Escherichia coli (80%), Stenotrophomonas maltophilia (75%), Pseudomonas aeruginosa (70%), Klebsiella pneumoniae (66.67%), Acinetobacter baumannii (36.36%) and Staphylococcus aureus (12.5%). Preliminary mNGS sequencing results showed that the pathogenic bacteria with higher abundance in the batch of effluent were Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis, Acinetobacter baumannii, Klebsiella aerogenes, Klebsiella michiganensis and Pseudomonas aeruginosa. In conclusion, phages of most common clinical Gram-negative pathogens were isolated from hospital wastewater with high isolation rates; however, phages of Gram-positive pathogens were isolated at lower rates, and only phages corresponding to Staphylococcus aureus were isolated in this study. The corresponding mNGS sequencing results showed that the distribution of Gram-negative pathogens in sewage may had a positive correlation with the ecological distribution of phages.

[Recent advances in the application of TAT, TM, t-PAIC and PIC in thromboembolism]

Thromboembolism is a crucial part of the global disease burden. It has high incidence, high mortality and disability rates, and the mechanism of occurrence and development is extremely complex. It is difficult to detect the disease in the early stage so that we have trouble with clinical prevention and treatment in general. At present, four items of blood coagulation and D-dimer have been widely used in the evaluation and auxiliary diagnosis of thromboembolism, the monitoring of effect for antithrombotic drugs and other fields. The thrombus biomarkers including thrombin-antithrombin complex (TAT), thrombomodulin (TM), tissue plasminogen activator-inhibitor complex (t-PAIC) and α2-plasmin inhibitor-plasmin complex (PIC) fill the gap of laboratory diagnosis before clinical symptoms appear in some degree. This article aims to explain the current application status of TAT, TM, t-PAIC and PIC in thromboembolism and explore their potential application value, so as to provide a reference for selecting appropriate early monitoring indicators for high-risk population of thromboembolism.

Phylogenetic characteristics of Non-SARS human coronavirus in southern Taiwan, 2012-2013

This study characterizes the phylogenetic relatedness of non-SARS human coronaviruses (HCoVs) in southern Taiwan by sequencing the nucleocapsid (N), spike (S), and RNA-dependent RNA polymerase (RdRp) genes directly from ten HCoV PCR-positive respiratory samples collected during 2012-2013. In the N, S1, and RdRp phylogeny, HCoV-OC43 in one and three samples was clustered with genotypes F and G, respectively, and HCoV-OC43 in sample YC101/TWN/2013 represented a recombination event between genotypes F and G. Amino acid substitutions in the S1 protein of HCoV-OC43 were also identified. In the N phylogeny, HCoV-HKU1 in one and two samples clustered with genotypes A and B, respectively, and HCoV-229E in two samples was clustered with genogroup 6. The genotypes and genogroup detected here were in line with the prevalent phylogenetic lineages reported outside of Taiwan during the contemporary period. In summary, three species of non-SARS HCoVs with different genotypes cocirculated in the community, with genetic evolution observed in HCoV-OC43.

Effect of replacing corn straw by sweet sorghum silage or whole plant corn silage in sheep diets on rumen fermentation and bacterial flora

Sweet sorghum silage (SS; Sorghum dochna 'Dochna') has been extensively studied in recent years as a supplementary forage-to-corn silage (CS; Zea mays L.), but there are still relatively few studies on its effects on the rumen environment of sheep. Determining the short-term impact of converting roughage from corn straws to SS compared to CS on rumen fermentation and bacterial population dynamics was the main goal of the current study. Twelve female thin-tailed Han sheep (29.8 ± 1.34 kg) were randomly divided into one of two treatments: concentrate supplemented with SS or CS, respectively. During the 15-day pretest period, concentrate was fed in two separate feedings at 0800 h and 1800 h, and ensure that the animals were all consumed within an hour of being fed. Thereafter, the animals had free access to corn straw. The feeding procedures during the pretest period were the same as during the measurement period. Rumen fluid was collected via sheep esophageal tube on the last day of adaptation phase (1-7 days) and stabilisation phase (8-30 days), respectively. The results showed that there was a similarity in the total concentration of VFA (volatile fatty acid) and the proportions of acetate, propionate, butyrate, and branched-chain VFA (P > 0.05) and microbial diversity indices (P > 0.05) between the two silage groups throughout the experimental period. The concentration of Ammonia nitrogen (P = 0.001) and proportion of valerate (P = 0.028) decreased in the CS and SS groups, respectively. The abundance and predicted function of rumen bacteria in the SS group did not differ significantly (P > 0.05) between the two measurement phases. However, the abundance of Prevotella_1 (P = 0.038) was higher in the CS group than in the SS group at 7 d. The abundances of Firmicutes (P = 0.005) and Ruminococcaceae_NK4A214_group (P = 0.002) increased, while the abundances of Bacteroidetes (P = 0.044), Proteobacteria (P = 0.046), and Prevotella_1 (P = 0.009) decreased in the CS group at 30 d. Genes related to pyruvate metabolism (P = 0.020) were significantly higher at 30 d than at 7 d, whereas purine metabolism (P = 0.007), pyrimidine metabolism (P = 0.007), and metabolic pathways (P = 0.010) were lower at 30 d in the CS group. In conclusion, this study indicated that SS maintained a steady rumen environment, while CS caused high fluctuations in bacterial abundance and predicted function for sheep.

Species distribution and antifungal susceptibility of clinical Aspergillus isolates: A multicentre study in Taiwan, 2016-2020

BACKGROUND

Epidemiological knowledge is important to guide antifungal therapy.

OBJECTIVE

This multicentre study aimed to investigate the species distribution and antifungal susceptibility of Aspergillus isolates in Taiwan.

METHOD

Four hundred and ninety-two clinical Aspergillus isolates, collected during 2016-2020, were identified by calmodulin sequencing and tested for antifungal susceptibility using CLSI M38-A3. The Cyp51A sequences of azole-resistant Aspergillus fumigatus and Aspergillus flavus isolates were analysed.

RESULTS

This collection comprised 30 species from eight Aspergillus sections-Flavi (33.5%), Nigri (26.0%), Fumigati (24.2%), Terrei (10.0%), Nidulantes (5.1%), Circumdati (0.8%), Restricti (0.2%) and Aspergillus (0.2%). Sections Fumigati, Flavi and Terrei were primarily represented by A. fumigatus (99.2%), A. flavus (95.8%) and A. terreus (100%), respectively. Section Nigri comprised nine species, mostly A. welwitschiae (60.2%), A. niger (12.5%), A. brunneoviolaceus (10.9%) and A. tubingensis (10.2%). A. fumigatus (39.6%) and A. flavus (26.4%) predominated among 53 isolates from lower respiratory samples, whereas section Nigri species (46.2%) and A. terreus (29.2%) predominated among 65 isolates from ear samples. Reduced susceptibility to amphotericin B (minimal inhibitory concentration (MIC) > 1 μg/mL) was noted in A. flavus (7.0%), A. terreus (6.1%), A. nidulans and section Circumdati (A. flocculosus, A. subramanianii and A. westerdijkiae) isolates. Acquired azole resistance was observed in seven A. fumigatus (5.9%), all of which carried TR₃₄ /L98H or TR₃₄ /L98H/S297T/F495I mutation, and three A. flavus (1.9%), one of which carried G441S mutation. Reduced susceptibility to itraconazole (MIC >1 μg/mL) was noted in 55.5% of section Nigri isolates, mainly in A. welwitschiae, A. niger and A. tubingensis, whereas A. brunneoviolaceus, A. aculeatinus and A. japonicus were hypersusceptible to azoles. Anidulafungin was active against all isolates except for one isolate.

CONCLUSIONS

This study depicted the molecular epidemiology and species-specific characteristics of Aspergillus in Taiwan, which aids in appropriate antifungal therapy and underlines the need of speciation and susceptibility testing of disease-causing Aspergillus.

[Clinical features of vestibular syncope associated with tumarkin attacks in delayed endolymphatic hydrops]

Objective: To analyze the clinical characteristics of vestibular syncope (VS) associated with drop attacks (DA) in delayed endolymphatic hydrops (DEH). Methods: DEH cases with complete data were retrospectively analyzed, including three DEH cases with DA and VS (VS group), and six DEH cases without DA or VS (control group). The clinical profile, the results of neurotological examinations [such as pure tone audiometry, electrocochleography (EcochG), caloric test, vestibular evoked myogenic potentials (VEMP), and video head impulse test (vHIT)] and treatment outcomes were analyzed. Results: (1) In the VS group, there were three cases of ipsilateral DEH; in the control group, there were six cases of ipsilateral type. One case in each group had a history of migraine. (2) The prevalence of abnormal results in caloric test, vHIT, cervical VEMP, and ocular VEMP in the VS group was 3/3, 1/3, 2/2, and 2/2, respectively, and in the control group was 3/6, 0/3, 1/6, and 4/6, respectively. Two cases in each group underwent EcochG, and no identifiable waveform was elicited on the affected side, and-SP/AP ratio of unaffected side was less than 0.4. (3) Patients in both groups were initially treated with conservative medication. Two cases in the VS group subsequently received intratympanic injections of dexamethasone. No DA or VS occurred during a follow-up period lasting over one year. All patients achieved good control of vertigo during the follow-up period. Conclusions: VS may occur in the patients with DEH. The differential diagnosis of syncope in patients with otogenic vertiginous disease can help improve clinical diagnosis and treatment.

P–522 Cervical secretion methylation profile is associated with the success of frozen-thawed embryo transfer - a proof-of-concept study

Study question

Is cervical secretion gene methylation profile different between receptive and non-receptive endometrium and associated with implantation outcome in frozen-embryo transfer (FET) cycle?

Summary answer

The combination of candidate genes methylation profiles obtained from cervical secretion showed significant associations with pregnancy outcomes.

What is known already

Implantation failure remains a black box in reproductive medicine, and the exact mechanism of how endometrial receptivity is regulated is still unknown. Epigenetic modifications play a role in the gene expression pattern and may alter the endometrial receptivity in the human endometrium. Cervical secretion containing various implantation-related cytokines, and the gene methylation change can be used as a non-invasive molecular source that reflects the endometrium condition.

Study design, size, duration

In this retrospective case-control study, sixty-two women who entered the FET cycle (30 pregnant and 32 non-pregnant women) were enrolled.

Participants/materials, setting, methods

Cervical secretion was collected before embryo transfer from women enrolled in multicenter university-affiliated reproductive units. The DNA methylation status of six candidate genes was measured using quantitative methylation-specific PCR (qMSP). The correlation between methylation change and the pregnancy outcome was analyzed.

Main results and the role of chance

The candidate genes were selected from that associated with implantation with literature review and the original genome-wide DNA methylation data from NCBI GEO DataSets (GSE90060) which processed using bioinformatics analysis. Six candidate genes whose CpG-level methylation analysis with β-value statistically higher in receptive endometrium than in a pre-receptive endometrium were selected. All six candidate genes showed different degrees of correlation with the pregnancy outcomes. Among them, PRKAG2 methylation changes showed the highest correlation with the pregnancy outcome. A logistic regression model was used to evaluate the performance of a single gene or a combination of genes for implantation prediction. The results showed a statistically significant association between the methylation status of a combination of genes (PRKAG2, KRS1, HAND2) and the pregnancy outcome (p = 0.008), resulting in an optimal AUC of 0.7 (95% CI: 0.57 - 0.81) for implantation prediction.

Limitations, reasons for caution

The results obtained from a relatively small cohort size. A larger study and further comprehensive methylome investigations are warranted.

Wider implications of the findings: This study is the first proof-of-concept study that cervical secretion methylation profile is associated with implantation outcome in a FET cycle, and showed potential as a non-invasive method for implantation prediction.

Trial registration number

non applicable

Multicenter Study of Azole-Resistant Aspergillus fumigatus Clinical Isolates, Taiwan1

In a multicenter study, we determined a prevalence rate of 4% for azole-resistant Aspergillus fumigatus in Taiwan. Resistance emerged mainly from the environment (TR₃₄/L98H, TR₃₄/L98H/S297T/F495I, and TR₄₆/Y121F/T289A mutations) but occasionally during azole treatment. A high mortality rate observed for azole-resistant aspergillosis necessitates diagnostic stewardship in healthcare and antifungal stewardship in the environment.

The extra domain A of fibronectin facilitates osteoclastogenesis in radicular cysts through vascular endothelial growth factor

AIM

To analyse the effects of the alternatively spliced fibronectin (FN) gene and its isoforms on osteoclastogenesis in radicular cysts.

METHODOLOGY

Specimens of radicular cysts were collected surgically from 22 patients whose radiolucent periapical areas were measured on digital panoramic radiographs before surgery. The associations between the radiolucent areas and FN isoforms, vascular endothelial growth factor (VEGF) expression or micro-vessel density, as well as the relationships amongst them, were analysed by immunohistochemical staining using the antibodies IST-9, BC-1, P1F11, VEGF and CD34. Fibroblasts isolated from those specimens were used to induce Trap + MNCs, and the effects of induction were assessed by blocking FN containing extra domain A (EDA + FN), COX-2 or VEGF in vitro. The effects of EDA exon knockout using CRISPR/Cas system were also assessed. Quantitative PCR was used to analyse relative expression of FN isoforms and osteoclastogenic genes. Data were analysed using linear regression, Spearman's rank correlation analysis, chi-square test and Student's t-test; P < 0.05 was considered significant.

RESULTS

Micro-vessel density and EDA + FN staining were positively associated with the size of radiolucent periapical areas (mm² ; P < 0.05), consistent with a positive association between Trap + MNCs and VEGF expression in fibroblasts (P < 0.05). Blocking the interaction between EDA + FN and fibroblasts inhibited Trap + MNC formation. In addition, EDA exon knockout decreased VEGF expression and inhibited Trap + MNC formation to the extent of blocking VEGF by bevacizumab, but osteoclastogenic induction was restored by recombinant VEGF. Using retrospective clinicopathological data, VEGF staining was shown to be positively associated with EDA + FN staining, micro-vessel density and the size of radiolucent areas (P < 0.05).

CONCLUSION

In fibrous capsules of radicular cysts, the alternatively spliced isoform EDA + FN generated by fibroblasts stimulated VEGF expression via an autocrine effect and then facilitated osteoclastogenesis. Both blockage of VEGF and EDA exon knockout could be used to inhibit bone destruction.

Azole resistance in Aspergillus species in Southern Taiwan: An epidemiological surveillance study

Poor clinical outcomes for invasive aspergillosis are associated with antifungal resistance. Performing antifungal susceptibility tests on clinically relevant Aspergillus isolates from patients and environmental regions with known azole resistance is recommended. The aim of the study was to assess the presence of azole resistance in clinical Aspergillus spp. isolates and those from hospital environments and farmlands within a 40 km radius of the hospital. Clinical Aspergillus spp. isolates were cultured, as well as environmental Aspergillus spp. isolates obtained from air samples. Samples were subcultured in azole-containing agar plates. Isolates with a positive screening test were subjected to YeastOne methods to determine their minimum inhibitory concentrations of antifungals. Resistance mechanisms were investigated in the azole-resistant Aspergillus spp. isolates. No azole-resistant clinical or environmental A flavus, A oryaze, A niger or A terreus isolates were found in the present study. All A fumigatus clinical isolates were azole-susceptible. Seven A fumigatus environmental isolates were associated with cyp51A mutations, including two that harboured TR₃₄ /L98H mutations with S297T/F495I substitutions, two with TR₃₄ /L98H mutations and three with TR₄₆ /Y121F/T289A mutations. One of these isolates was collected from farmland, one was from A ward and five were from B ward. The proportion of azole-resistant A fumigatus was 10.2% (6/59) and 3.2% (1/31) in the hospital environments and the farmlands near the hospital, respectively. The results showed that azole-resistant A fumigatus existed within hospital environments. This emphasises the importance of periodic surveillance in hospital environments and monitoring for the emergence of azole-resistant A fumigatus clinical isolates.

[Research progress in graphene derivatives promoting bone regeneration]

Graphene derivatives are the new bioactive material with good physical and chemical properties and excellent biocompatibility. It has been found that graphene derivatives can improve the mechanical properties of biomaterials and promote the adhesion, proliferation and differentiation of osteoblast-related cells, so as to promote implant-bone bonding and repair of bone defects. This makes it a research hotpot in the field of bone tissue regeneration. In this paper, the mechanism of graphene derivatives promoting bone regeneration and their application in the oral field were reviewed, so as to provide theoretical basis for their application in basic and clinical research.

[Effects of ketotifen on fractional exhaled nitric oxide in patients with combined allergic rhinitis and asthma syndrome]

Objective:To study effects of ketotifen on fractional exhaled nitric oxide in patients with combined allergic rhinitis and asthma syndrome.Method:One hundred and twelve patients with asthma were selected from department of respiration, Affiliated Hospital of North China University of science and technology from January 2016 to 2017 in March. Eighty-four patients with allergic rhinitis were selected as the subjects, Randomly divided into two groups,including observed group(n=42) and control group(n=42).The control group was treated with antitussive,expectorant and inhaled corticosteroids, while the observed group in the control group combined with ketotifen 1 mg 2/ day oral treatment,the changes of FeNO and IL-17 in the two groups were compared after one month treament.Result:Before treatment, two groups of patients in general IL-17 and fractional exhaled nitric oxide ware no significant difference(P> 0.05).After treatment, compared to the control group, the observed group was significantly more effective,the difference was statistically significant(P <0.05);fractional exhaled nitric oxide in treatment group were lower than those in control group, the difference was statistically significant(P&lt;0.05,P< 0.01).And the observed group was lower than the control group, and the differences were statistically significant,t(P<0.05).Conclusion:Ketotifen significantly reduce the FeNO of allergic rhinitis and asthma syndrome, reduce airway inflammation.

[The effect of monrustet on the exhalation of nitric oxide and inflammatory cytokines in patients with asthma combined with OSAHS]

Objective:To study the effect of monrustet on fractional exhaled nitric oxide and inflammatory cytokines in the elderly with bronchial asthma combined obstructive sleep apnea hypopnea syndrome.Method:150 cases diagnosed as asthma were enrolled in this study. The patients were divided into bronchial asthma combined with OSAHS (n=72)and bronchial asthma (n=78). According to the different treatment methods , patients were divided into observation group and control group. Two groups were given common treatment with inhaled corticosteroids, and the observation group was taken orally montrast 10mg/night additionally. The fractional exhaled nitric oxide was detected before and after treatment. Serum were collected for detection of tumor necrosis factor alpha (TNR-α), Creactive protein (CRP) and interleukin 6 (IL-6), according to the sleep monitoring results, the sleep apnea low ventilation index (AHI) was calculated, and the changes of FeNO level,CRP,TNR-α,IL-6 and AHI were analyzed in the two groups.Result:Before treatment, the gender, age, degree of disease, FeNO level,TNR-α, CRP,IL-6 and AHI differences were not statistically significant in the two groups (P>0.05).After treatment, both groups of FeNO, TNR-α,CRP,IL-6 and AHI decreased before treatment (P < 0.05).The observation group was lower than the control group, and the difference was statistically significant (FeNO level, AHIP< 0.01,TNR-α, CRP,IL-6 P< 0.05).Conclusion::Montelukast can reduce the FeNO level, the expression of TNR-α, CRP, and IL-6 of patients of bronchial asthma combined with OSAHS. Further improvement of the patient's condition, and provide reference value for the clinical medicine of patients with asthma.

Acute nutrient treatment causes alterations in intra-follicular antioxidation and AKT signaling

This study aimed to determine if short-term nutrient alteration affects (1) ovarian morphology, (2) plasma and ovarian antioxidant capability and (3) cell apoptosis and AKT signaling within the ovary. After estrus synchronization, 24 Hu sheep were assigned to three groups based on the nutrient requirement recommended for maintenance (M): 1 × M (Control), 1.5 × M (S) and 0.5 × M (R) during days 7–14 of their estrous cycle. The results indicated that undernourishment significantly increased the counts and volume of follicles <2.5 mm and decreased the counts and volume of follicles ≥2.5 mm (P < 0.05). Feed restriction altered the plasma and follicular redox balance within follicles ≥2.5 mm by inhibiting total antioxidant capacity, increasing malondialdehyde concentration (P < 0.05) and reducing the mRNA expression levels of superoxide dismutase 2 (SOD2) and glutathione peroxidase (GSH-PX), as well as the activities of total SOD and GSH-PX. Feed restriction also attenuated B-cell lymphoma-2 (BCL2) but enhanced Bcl-2-associated X protein (BAX) andBAX/BCL2transcription and translation levels in granulosa cells (P < 0.05). Uniform staining intensities of AKT and P-AKT-Ser473 were observed in each follicle stage, whereas weaker P-AKT-Thr308 staining in the antral follicle than in the pre-antral follicle suggested possible involvement of P-AKT-Thr308 during the beginning of follicle development. P-AKT-Ser473 levels in follicles ≥2.5 mm was significantly reduced in the R group (P < 0.05). The results presented in this study demonstrate that suppressed folliculogenesis caused by feed restriction might be associated with attenuated AKT signaling, reduced follicular antioxidant capacity and enhanced granulosa cells apoptosis.

Prevalence, mechanisms and genetic relatedness of the human pathogenic fungus Aspergillus fumigatus exhibiting resistance to medical azoles in the environment of Taiwan

Emerging azole resistance in Aspergillus fumigatus poses a serious threat to human health. This nationwide surveillance study investigated the prevalence and molecular characteristics of azole-resistant A. fumigatus environmental isolates in Taiwan, an island country with increasing use of azole fungicides. Of the 2760 air and soil samples screened from 2014 to 2016, 451 A. fumigatus isolates were recovered from 266 samples and 34 isolates from 29 samples displayed resistance to medical azoles (itraconazole, voriconazole or posaconazole). The resistance prevalence was 10.9% and 7.5% in A. fumigatus-positive samples and isolates respectively. Most (29, 85.3%) azole-resistant isolates harboured TR₃₄ /L98H mutations, which were widely distributed, clustered genetically with clinical isolates, and had growth rates that were similar to those of the wild-type isolates. Microsatellite genotyping revealed both the global spread of the TR₃₄ /L98H isolates and the occurrence of TR₃₄ /L98H/S297T/F495I isolates belonging to local microsatellite genotypes. AfuMDR3 and atrF, two efflux transporter genes, were constitutively upregulated in two individual resistant isolates without cyp51A mutations, highlighting their potential roles in azole resistance. These results emphasize the need for periodic environmental surveillance at the molecular level in regions in which azole fungicides are applied, and agricultural fungicide management strategies that generate less selective pressure should be investigated.

Application of polarization information to a light-controlling-light technique

Nonlinear effects of photo-induced waveguides based on isomerization photochemistry are investigated. It is found that polarization information of the controlling light can be used to control the propagation of the signal light in all-optical waveguides, and an accurate and convenient light-controlling-light scheme is proposed, that is, controlling propagation of the signal light by synergic use of the intensity information and polarization information of the controlling light. The polarization dependence of optical nonlinearity is expected to enrich the connotation of the optical nonlinear effects and has theoretical significance and practical value.

Cloning of oligopeptide transport carrier PepT1 and comparative analysis of PepT1 messenger ribonucleic acid expression in response to dietary nitrogen levels in yak () and indigenous cattle () on the Qinghai-Tibetan plateau

The gastrointestinal lumen can directly absorb all di- and tripeptide protein degradation products, and oligopeptide absorption depends on the specific peptide transport carriers, which are located in gastrointestinal epithelial cells on the brush border membrane. Yak () use N more efficiently than cattle do, which implies that yak have a specific mechanism of nonprotein utilization including a peptide absorption mechanism. However, this mechanism has not been clarified. Our objective was to explore whether yak possess any adaptive mechanisms of peptide absorption to survive in the harsh foraging environment of the Qinghai-Tibetan plateau. Twelve castrated males of each of 2 genotypes, yak () and indigenous cattle (), were fed diets of various N levels. The yak PepT1 (yPepT1) cDNA was cloned in omasum epithelial tissue. Our results showed that the full-length yPepT1 cDNA contains 2,805 bp, and a 2,121-bp open reading frame encodes a putative protein of 707 AA residues. The yPepT1 AA sequence identified 5 putative extracellular N-glycosylation sites (Asn, Asn, Asn, Asn, and Asn), 2 putative intracellular protein kinase A sites (Ser and Thr), and 3 intracellular putative protein kinase C sites (Ser, Ser, and Ser). The yPepT1 AA sequence was 99, 95, 86, and 83% identical to PepT1 from cattle (), sheep (), pigs (), and humans (), respectively. The relative PepT1 mRNA expression for indigenous cattle was greater than yak in the rumen, omasum, duodenum, ileum, and liver ( < 0.001); however, it was lower in jejunum tissue ( < 0.01). The relative PepT1 mRNA expression in response to increasing dietary N for both genotypes were linear in the rumen and jejunum ( < 0.10); quadratic or cubic in the reticulum ( < 0.01); linear or quadratic in the duodenum, ileum, and liver ( ≤ 0.01); and linear, quadratic, or cubic in the omasum ( < 0.001). Moreover, there were significant interactions between genotype and dietary N in rumen, reticulum, omasum, duodenum, jejunum, ileum, and liver tissues. In conclusion, the PepT1 profile and expression in gastrointestinal epithelial cells of yak varied from those of cattle, implying that yak have evolved a peptide transport mechanism to adapt the environment of the Qinghai-Tibetan plateau.

[Epidemic features of dyslipidemia among Uygur, Kazakh and Han ethnic groups in Urumqi]

Objective: To analyze the epidemic features of dyslipidemia among 39 980 Uygur, Kazak and Han ethnic groups in Urumqi, and to explore the methods of prevention and treatment on dyslipidemia. Methods: The differences of blood total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) of health examination population with different ethnics, genders, and ages were compared, from 2012 to 2014 in the First Affiliated Hospital of Xinjiang Medical University. Results: Among the Uygur, Kazak and Han ethnic groups, the positive rate was respectively 35.0%, 37.0%, 30.3% in TC; 34.5%, 30.1% and 32.0% in TG; 24.9%, 18.3%, and 18.2% in HDL-C; 30.1%, 31.6% and 23.3% in LDL-C. In the same ethnic group, the abnormality rate of blood lipid in the female was lower than that of the male (P<0.001). The blood lipid abnormality rate increased significantly in those with 30-39 years, and reached the highest value in the 50-59 years group, then it decreased in those aged over 60 years (P<0.001). Conclusion: The lipid abnormality rate of the Uygur and Kazak residents was higher than that of the Han nationality, and the abnormal levels of TC and LDL-C were particularly evident in Urumqi.

Two-beam combined 3.36 J, 100 Hz diode-pumped high beam quality Nd:YAG laser system

In this paper, we develop a diode-pumped all-solid-state high-energy and high beam quality Nd:YAG laser system. A master oscillator power amplifier structure is used to provide a high pulse energy laser output with a high repetition rate. In order to decrease the amplifier working current so as to reduce the impact of the thermal effect on the beam quality, a beam splitting-amplifying-combining scheme is adopted. The energy extraction efficiency of the laser system is 50.68%. We achieve 3.36 J pulse energy at a 100 Hz repetition rate with a pulse duration of 7.1 ns, a far-field beam spot 1.71 times the diffraction limit, and 1.07% energy stability (RMS).