ABSTRACT
Polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine (PPA) have various biological activities, but their properties after oral administration are not clear. In this study, the absorption, digestion and fermentation properties of PPA were studied using in vivo fluorescence tracking, in vitro simulated digestion and fecal fermentation experiments. The absorption experiment showed that fluorescence was only observed in the gastrointestinal system, indicating that PPA could not be absorbed. Simulated digestion results showed that there were no significant changes in the molecular weight, Fourier transform infrared spectroscopy (FT-IR) spectrum, monosaccharides and reducing sugar of PPA during the digestion process, showing that the overall structure of PPA was not damaged. However, the carbohydrate gel electrophoresis bands of PPA enzymatic hydrolysates after simulated digestion were significantly changed, indicating that simulated digestion might impact the configuration of PPA. In vitro fermentation showed that PPA could be degraded by microorganisms to produce short chain fatty acids, leading to a decrease in pH value. PPA can promote the proliferation of Bacteroideaceae, Megasphaera, Bacteroideaceae, and Bifidobacteriaceae, and inhibit the growth of Desulfobacteriota and Enterobacteriaceae. The results indicated that PPA could treat diseases by regulating gut microbiota, providing a scientific basis for the application and development of PPA.
Subject(s)
Digestion , Feces , Fermentation , Gastrointestinal Microbiome , Polysaccharides , Gastrointestinal Microbiome/drug effects , Polysaccharides/chemistry , Polysaccharides/pharmacology , Humans , Feces/microbiology , Feces/chemistry , Digestion/drug effects , Pinellia/chemistry , AnimalsABSTRACT
Despite significant progress in diagnosis and treatment, asthma remains a serious public health challenge. The conventional therapeutic drugs for asthma often have side effects and unsatisfactory clinical efficacy. Therefore, it is very urgent to develop new drugs to overcome the shortcomings of conventional drugs. Natural polysaccharides provide enormous resources for the development of drugs or health products, and they are receiving a lot of attention from scientists around the world due to their safety, effective anti-inflammatory and immune regulatory properties. Increasing evidence shows that polysaccharides have favorable biological activities in the respiratory disease, including asthma. This review provides an overview of primary literature on the recent advances of polysaccharides from natural resources in the treatment of asthma. The mechanisms and practicability of polysaccharides, including polysaccharides from plants, fungus, bacteria, alga, animals and others are reviewed. Finally, the further research of polysaccharides in the treatment of asthma are discussed. This review can provide a basis for further study of polysaccharides in the treatment of asthma and provides guidance for the development and clinical application of novel asthma treatment drugs.
Subject(s)
Asthma , Polysaccharides , Animals , Polysaccharides/pharmacology , Polysaccharides/therapeutic use , Bacteria , Natural Resources , Asthma/drug therapyABSTRACT
BACKGROUND Thoracoscopic lobectomy is accompanied by intense trauma and pain due to impaired chest wall integrity. We aimed to introduce a modified ultrasound-guided serratus anterior plane block (MUG-SAPB) for postoperative analgesia in patients who underwent thoracoscopic lobectomy, and to determine whether it could effectively alleviate postoperative pain and improve recovery quality. MATERIAL AND METHODS Overall, 78 patients randomly received either combined MUG-SAPB (0.25% ropivacaine, 10 mg dexamethasone, 40 mL) with patient-controlled intravenous analgesia (PCIA) or received PCIA alone. The primary outcomes were visual analog scale (VAS) scores at rest and during movement at 4, 8, 12, 20, 24, 48, and 72 h postoperatively. The secondary outcomes included use of opioids during surgery, numbers of rescue analgesics (butorphanol), frequency of patient-controlled analgesia (PCA), comfort score within 24 h postoperatively, and postoperative complications within 72 h. RESULTS Compared to the PCIA group, in the MUG-SAPB group, resting VAS scores at 4-24 h (P<0.05) and movement VAS scores at 4-12 h postoperatively (P<0.05) were lower; intraoperative use of sufentanil and frequency of PCA were less, and less rescue analgesia was used (P=0.02, P=0.04 and P=0.03, respectively). Patients in the MUG-SAPB group had faster first mobilization (P=0.04). The MUG-SAPB group had higher comfort scores than the PCIA group (P=0.03). None of the MUG-SAPB patients had any SAPB-related complications. CONCLUSIONS MUG-SAPB effectively relieved postoperative pain, reduced opioid consumption, and accelerated early ambulation in comparison with PCIA alone in patients who underwent thoracoscopic lobectomy.
Subject(s)
Nerve Block , Humans , Nerve Block/methods , Pain Management , Analgesia, Patient-Controlled , Pain, Postoperative/drug therapy , Pain, Postoperative/etiology , Analgesics, Opioid/therapeutic use , Ultrasonography, Interventional/methodsABSTRACT
INTRODUCTION: Mandibular asymmetry has negative impacts on maxillofacial aesthetics and psychological well-being. This study investigated the effects of unilateral injection of botulinum toxin type A (BTX-A) into the masseter muscle on mandibular symmetry. METHODS: Forty Wistar rats (4-week-old) were divided into 4 groups (n = 10): control, group 1 (1U BTX-A), group 2 (3U BTX-A), and group 3 (1U BTX-A for 3 times). BTX-A was injected into the right masseter of treatment groups. Cone-beam computerized tomography scans were taken before the injection and then at 2 weeks, 4 weeks, and 6 weeks after injection. Histologic and immunohistochemical staining were done for the condylar cartilage. RNA sequencing and quantitative reverse transcription polymerase chain reaction were used to detect gene expression in the angular process. RESULTS: In Groups 2 and 3, the right angular process length and the ramus height were reduced 4 weeks after injection, resulting in the mandibular midline deviating to the right side; the right condylar cartilage had reduced thickness and decreased expression of RUNX2, SOX9, and COL II (P <0.05). Two hundred sixty-one genes were differentially expressed (256 downregulated) in the angular process at 3 days post-BTX-A injection, and the calcium signaling pathway was unveiled through the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Furthermore, TRPC1, Wnt5a, CaMKII, Ctnnb1, and RUNX2 expression were significantly downregulated at 1 and 3 days postinjection. CONCLUSIONS: Unilateral injection of BTX-A into the masseter muscle in adolescent rats induces mandibular asymmetry by suppressing the angular process growth on the injected side.
Subject(s)
Botulinum Toxins, Type A , Rats , Animals , Botulinum Toxins, Type A/pharmacology , Masseter Muscle , Core Binding Factor Alpha 1 Subunit , Rats, Wistar , Esthetics, DentalABSTRACT
BACKGROUND: Early detection of solid pancreatic masses through contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) is important. But CH-EUS is difficult to learn. PURPOSE: To design a deep learning-based CH-EUS diagnosis system (CH-EUS MASTER) for real-time capture and segmentation of solid pancreatic masses and to verify its value in the training of pancreatic mass identification under endoscopic ultrasound (EUS). METHODS: We designed a real-time capture and segmentation model for solid pancreatic masses and then collected 4530 EUS images of pancreatic masses retrospectively, used for training and testing of this model at a ratio of 8:2. The model is loaded into the EUS host computer to establish the CH-EUS MASTER system. A crossover trial was then conducted to evaluate the model's value in EUS trainee training by successfully conducting two groups of EUS trainees in model learning and trainer-guided training. The intersection over union (IoU) and the time to find the lesion were used to evaluate the model performance metrics, and the Mann-Whitney test was used to compare the IoU and the time to find the lesion in different groups of subjects. Paired t-test was used to compare the effects before and after training. When α ≤ 0.05, it is considered to have a significant statistical difference. RESULTS: The model test showed that the model successfully captured and segmented the pancreatic solid mass region in 906 EUS images. The real-time capture and segmentation model had a Dice coefficient of 0.763, a recall rate of 0.941, a precision rate of 0.642, and an accuracy of 0.842 (when the threshold is set to 0.5), and the median IoU of all cases was 0.731. For the AI training effect, the average IoU of eight trainees improved from 0.80 to 0.87 (95% CI, 0.032-0.096; p = 0.002). The average time for identifying lesions in the pancreatic body and tail improved from 22.75 to 17.98 s (95% CI, 3.664-5.886; p < 0.01). The average time for identifying lesions in the pancreatic head and uncinate process improved from 34.21 to 25.92 s (95% CI, 7.661-8.913; p < 0.01). CONCLUSION: CH-EUS MASTER can provide an effect equivalent to trainer guidance in training pancreatic solid mass identification and segmentation under EUS.
Subject(s)
Deep Learning , Pancreatic Neoplasms , Humans , Pancreatic Neoplasms/diagnostic imaging , Retrospective Studies , Endosonography/methods , Pancreas/diagnostic imagingABSTRACT
Background: Laparoscopic sleeve gastrectomy (LSG) is a sustainable technique that effectively treats morbid obesity. However, the molecular mechanisms underlying the improvement of metabolic health following this process warrants more investigation. This study investigates LSG-related molecules and uses bulk RNA-sequencing high-throughput analysis to unravel their regulatory mechanisms. Methods: Peripheral blood mononuclear cells (PBMC) were collected from ten obese patients with BMI ≥ 32.5 kg/m2 in the Department of General Surgery of Kunming First People's Hospital. After LSG, patients were followed up for one month, and blood samples were retaken. Blood samples from ten patients before and after LSG and bulk RNA-Seq data were analyzed in this study. LSG-associated gene expression was detected by weighted gene coexpression network analysis (WGCNA) and differential analysis. Subsequently, essential signature genes were identified using logistic least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) algorithms. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and single-sample gene set enrichment analysis (ssGSEA) were utilized to reveal the potential functions of the target genes. Furthermore, the Pearson correlation of signature genes with leptin and lipocalin was also explored. Finally, we constructed a robust endogenous RNA (ceRNA) network based on miRWalk and starBase databases. Results: We identified 18 overlapping genes from 91 hub genes, and 165 differentially expressed mRNAs (DE-mRNA), which were revealed to be significantly associated with immune cells, immune response, inflammatory response, lipid storage, and localization upon functional enrichment analysis. Three signature genes, IRF1, NFKBIA, and YRDC, were identified from the 18 overlapping genes by LASSO and SVM-REF algorithms. The logistic regression model based on the three signature genes highlighted how robustly they discriminated between samples. ssGSEA indicated these genes to be involved in lipid metabolism and degradation pathways. Moreover, leptin levels were significantly reduced in patients undergoing LSG, and NFKBIA significantly negatively correlated with leptin. Finally, we identified how the long non-coding RNA (lncRNA) ATP2B1-AS1 regulated the expression of the signature genes by competitively binding to six microRNAs (miRNAs), which were hsa-miR-6509-5p, hsa-miR-330-5P, hsa-miR-154-5P, hsa-miR-145-5P, hsa-miR4726-5P and hsa-miR-134-5P. Conclusion: This study identified three critical regulatory genes significantly differentiated between patients before and after LSG treatment and highlighted their potentially crucial role after bariatric surgery. This provides novel insights to increase our understanding of the underlying mechanisms of weight loss and associated metabolic improvement after bariatric surgery.
Subject(s)
Laparoscopy , MicroRNAs , Obesity, Morbid , Humans , Leptin , Leukocytes, Mononuclear , Transcriptome , East Asian People , Obesity, Morbid/genetics , Obesity, Morbid/surgery , RNA-Binding Proteins , GTP-Binding Proteins , Plasma Membrane Calcium-Transporting ATPasesABSTRACT
The pericarp of Zanthoxylum bungeanum maxim (PZM) is a commonly used spice and herbal medicine in China. In the present study, the structural characteristics of PPZM were investigated by saccharide mapping after enzymatic digestion by using high-performance thin layer chromatography (HPTLC) and polysaccharide analysis by using carbohydrate gel electrophoresis (PACE). The mechanisms of protective effects of PPZM on Aß25-35-induced oxidative damage were explored in PC12 cells. The results showed that PPZM contained 1,4-α-D-galactosidic, 1,4-α-D-galactosiduronic, and (1â4)-ß-D-glucosidic linkages. Pretreatment with PPZM significantly increased the cell viability of Aß25-35-injured PC12 cells. Flow cytometry and Hoechst/PI staining indicated that PPZM gradually relieved the apoptosis of the Aß25-25-treated cells. PPZM markedly decreased the ROS level of PC12 cells and suppressed Aß25-35-induced oxidative stress by increasing the SOD level, and decreasing the level of MDA and LDH. The mRNA expressions of caspase-3 and Bax were significantly downregulated, and Bcl-2 expression was upregulated by treatment with PPZM. PPZM significantly increased the mRNA expression of Nrf2 and HO-1 in Aß25-35 treated cells. The results indicated that PPZM alleviated apoptosis and oxidative stress induced by Aß25-25 through the inhibition of mitochondrial dependent apoptosis and activation of Nrf2/HO-1 pathway. PPZM can be used as a potential protective agent against Aß25-25-induced neurotoxicity.
Subject(s)
Neuroprotective Agents , Zanthoxylum , Animals , Rats , Neuroprotective Agents/pharmacology , Zanthoxylum/metabolism , NF-E2-Related Factor 2/metabolism , Oxidative Stress , Apoptosis , Polysaccharides/chemistry , PC12 Cells , RNA, Messenger/metabolism , Amyloid beta-Peptides/metabolism , Peptide Fragments/metabolismABSTRACT
BACKGROUND AND AIMS: Distinguishing pancreatic cancer from nonneoplastic masses is critical and remains a clinical challenge. The study aims to construct a deep learning-based artificial intelligence system to facilitate pancreatic mass diagnosis, and to guide EUS-guided fine-needle aspiration (EUS-FNA) in real time. METHODS: This is a prospective study. The CH-EUS MASTER system is composed of Model 1 (real-time capture and segmentation) and Model 2 (benign and malignant identification). It was developed using deep convolutional neural networks and Random Forest algorithm. Patients with pancreatic masses undergoing CH-EUS examinations followed by EUS-FNA were recruited. All patients underwent CH-EUS and were diagnosed both by endoscopists and CH-EUS MASTER. After diagnosis, they were randomly assigned to undergo EUS-FNA with or without CH-EUS MASTER guidance. RESULTS: Compared with manual labeling by experts, the average overlap rate of Model 1 was 0.708. In the independent CH-EUS video testing set, Model 2 generated an accuracy of 88.9% in identifying malignant tumors. In clinical trial, the accuracy, sensitivity, and specificity for diagnosing pancreatic masses by CH-EUS MASTER were significantly better than that of endoscopists. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were respectively 93.8%, 90.9%, 100%, 100%, and 83.3% by CH-EUS MASTER guided EUS-FNA, and were not significantly different compared to the control group. CH-EUS MASTER-guided EUS-FNA significantly improved the first-pass diagnostic yield. CONCLUSION: CH-EUS MASTER is a promising artificial intelligence system diagnosing malignant and benign pancreatic masses and may guide FNA in real time. TRIAL REGISTRATION NUMBER: NCT04607720.
Subject(s)
Deep Learning , Pancreatic Neoplasms , Humans , Artificial Intelligence , Endoscopic Ultrasound-Guided Fine Needle Aspiration , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/pathology , Prospective StudiesABSTRACT
BACKGROUND: Except for public health case reports, the incidence of Zika virus (ZIKV), chikungunya virus (CHIKV), and dengue virus (DENV) infection are not available to assess the potential blood transfusion safety threat in Brazil. METHODS: Pools of 6 donation samples (MP6) left over from human immunodeficiency virus, hepatitis B virus, and hepatitis C virus nucleic acid testing were combined to create MP18 pools (3 MP6 pools). Samples were tested using the Grifols triplex ZIKV, CHIKV, and DENV real-time transcription mediated amplification assay to estimate prevalence of RNAemia and incidence, and to compare these results to case reports in São Paulo, Belo Horizonte, Recife, and Rio de Janeiro, from April 2016 through June 2019. RESULTS: ZIKV, CHIKV, and DENV RNAemia were found from donors who donated without overt symptoms of infection that would have led to deferral. The highest RNAemic donation prevalence was 1.2% (95% CI, .8%-1.9%) for DENV in Belo Horizonte in May 2019. Arbovirus infections varied by location and time of year, and were not always aligned with annual arbovirus outbreak seasons in different regions of the country. CONCLUSIONS: Testing donations for arboviruses in Brazil can contribute to public health. Transfusion recipients were likely exposed to ZIKV, CHIKV, and DENV viremic blood components during the study period.
Subject(s)
Arboviruses , Chikungunya Fever , Chikungunya virus , Dengue Virus , Dengue , Zika Virus Infection , Zika Virus , Humans , Chikungunya Fever/epidemiology , Brazil/epidemiology , Blood Donors , IncidenceABSTRACT
Since glass fiber-reinforced polymer (GFRP) bars have a lower modulus than steel bars, the design of GFRP-reinforced concrete (GFRP-RC) is often governed by the serviceability limit state (deflection and cracking) rather than the ultimate state. A new design method has been proposed in this paper for GFRP-RC beams based on the flexure crack width. The state when the maximum flexure crack width in the tensile zone reaches the limit of 0.5 mm specified by ACI 440.1R-15 was used as the design limit state. The concrete compressive strain at the extreme compression fiber of concrete under the design limit state was obtained by four-point bending tests of eight full-scale GFRP-RC beams and finite element analysis. Based on the concrete compressive strain under the design limit state and cross-sectional analysis, a design method for calculating the longitudinal reinforcement ratio of GFRP-RC beams under the design limit state is proposed. This design method is proven to be feasible by the experimental and the finite element results. In addition, the flexural capacity coefficient was discussed to investigate the safety reserve of the design method.
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Background: Complete resection (CR) serves as the standard of surgical treatment for retroperitoneal liposarcoma (RPLS). Unfortunately, even at referral centers, recurrence rates are high, and CR may not address multifocal diseases, which are a common phenomenon in RPLS. We sought to retrospectively compare the clinical outcomes of RPLS patients treated with total (ipsilateral) retroperitoneal lipectomy (TRL) and CR. Because TRL remove potentially multifocal tumors in the fat, patients may have a better prognosis than CR. Methods: Patients with primary/first-recurrent RPLS who had been treated at 5 referral centers were recruited from December 2014 to June 2018. Multivariable Cox regression analyses were conducted to determine the effects of demographic, operative, and clinicopathological variables on the following primary endpoints: local recurrence (LR), local recurrence-free survival (LRFS), and overall survival (OS). Results: A total of 134 patients were enrolled in this retrospective study, 53 of whom underwent TRL, and 81 of whom underwent CR. The 2 groups were comparable in terms of age, gender, presentation (primary vs. first-recurrent RPLS), number of tumors (unifocal vs. multifocal) at presentation, and Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade. The TRL group had higher levels of preoperative hemoglobin (Hb) (13 vs. 12.5 g/dL; P=0.008) and a lower amount of intraoperative blood loss (400 vs. 500 mL; P=0.034), but there were no significant differences in the length of hospital stay (23 vs. 22 d; P=0.47) or complications (32 vs. 30; P=0.82) between the 2 groups. In a subset of patients with multifocal tumors at initial presentation, OS was more prolonged in those treated with TRL than those treated with CR (P=0.0272). Based on the multivariable analysis, primary liposarcoma and a low FNCLCC grade were associated with decreased LR and improved OS. Conclusions: TRL is a safe procedure that positively affects the OS of patients with multifocal RPLS. This novel strategy deserves further investigation in prospective studies.
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With the large-scale construction of suburban railway viaducts, the noise problem along the viaducts is becoming more and more prominent. Conventional vertical noise barriers have been widely used to alleviate the noise problem along the suburban railway viaducts. However, conventional vertical noise barriers often have an adverse effect on the urban landscape and also block the view of train drivers and passengers. A type of near-rail low-height noise barrier was planned to install on the viaducts of Wenzhou Rail Transit Line S1 to reduce the impact of noise on residents along the railway lines. To assess the acoustic performance of the near-rail low-height noise barrier, a numerical procedure for railway viaduct comprehensive noise considering wheel-rail noise and structure-borne noise of the bridge and noise barriers was proposed and then verified by a field test. On this basis, numerical models were established to compare the acoustic performances of the near-rail low-height noise barrier and conventional vertical noise barrier. The influences of the height and top shape of the near-rail low-height noise barrier on the acoustic performance were discussed. Based on the numerical analysis results, it is found that both the near-rail low-height noise barrier and conventional vertical noise barrier have good acoustic performances. The noise reduction effect of the near-rail low-height noise barrier is slightly better than that of the conventional vertical noise barrier. The acoustic performance of the near-rail low-height noise barrier gradually improves, but the improvement rate gradually slows down as the height of the noise barrier increases. The noise reduction effects of both the inverted L-shaped and Y-shaped near-rail low-height noise barrier are obviously better than that of the vertical one, while the noise reduction effects of the inverted L-shaped near-rail low-height noise barrier are slightly better than the Y-shaped one.
Subject(s)
Railroads , Acoustics , NoiseABSTRACT
In view of the coal and gas outburst accidents occur frequently caused by blasting in geological structural belt, in order to study the mechanical characteristics of coal rock in tectonic belt disturbance by blasting and blasting vibration effect influenced on the stability of surrounding rock, coal-rock damage and failure characteristics within a reverse fault caused by a blasting stress wave were investigated using numerical analyses and experiments. According to the experimental results, the causes of coal and gas outburst dynamic disasters within a reverse fault during blasting are analyzed. The outcomes indicated that the crushing circle created by the crack propagation near the blasting hole severely damaged the fault plane and floor rocks adjacent to the footwall of the reverse fault. Fractures also extended to the upper and lower coal seams of the reverse fault; this caused the surface of the coal seam to fall off and severe internal damage. According to theoretical analysis, the reflection of the blasting stress wave propagating to the reverse fault intensified the damage to coal and rock. Elastic strain energy accumulation within the reverse fault structural zone was accompanied by high-stress concentration. The reverse fault tectonic region was destroyed by blasting vibration. It increased gas pressure and caused a weak surface, which provided a channel for gas flow and a dynamic basis for the occurrence of coal and gas outburst. The research results have important theoretical value to reveal the mechanism of coal and gas outburst in tectonic belt induced by blasting.
ABSTRACT
In the present work, the working state of the crane leg is analyzed and discussed, and its structure is optimized. SolidWorks software is used for modeling; ANSYS software is used for finite element analysis. First of all, the constrained finite element method (CFEM) is used to analyze the linear eigenvalue buckling and geometric nonlinear buckling of outriggers with different cross-section shapes. Prove that the curved leg has certain advantages in buckling. At the same time, analyzing the leg along a different path of buckling condition and stress changes provide the basis for the design of the subsequent reinforcement. After selecting the best cross-section shape of the outrigger, the agent-based multi-island genetic algorithm is used to optimize the structural parameters of the outrigger under the transverse stiffened plate reinforced structure and the longitudinally stiffened plate reinforced structure respectively. It is proved that the outrigger with the transverse stiffened plate has a significant effect in improving the bearing capacity and in the lightweight of the structure. Finally, the gap between the movable leg and the fixed leg was changed, the stress of different gaps was analyzed by using the finite element method, and the appropriate gap value was selected according to the high-order fitting curve.
Subject(s)
Algorithms , Bone Plates , Finite Element AnalysisABSTRACT
In this paper, a thermal convection-based optofluidic conveyor has been introduced, which can flexibly capture and manipulate multiple 20-120 µm silica particles with utmost accuracy. Near the end face, a fiber-based light source can confine 100 µm silica particles within 100 microns. By switching the light source of the fiber array, centimeter-range transportation of 100 µm SiO2 particles has been successfully achieved, which was not possible in optical trapping devices as we know. Through the comparative experiment with silica, polystyrene, and zirconium dioxide particles, the presented conveyor system is proved to be independent of the particles' dielectric properties. Moreover, sorting of silica and polystyrene particles based on the difference of mass densities has also been achieved. Additionally, the components of this conveyor (fiber array) and chip parts (microfluidic chamber) are freely detachable. Here, instead of expensive laser systems, a non-coherent light source has been utilized, which eventually eliminates the use of optical lens assemblies. All these features lead to making the equipment extremely simple in structure and low in cost. Besides, this optofluidic conveyor can be applied to transmit and sort various objects such as blood/cancer cells and microorganisms.
ABSTRACT
With the continuous development of production technology, the performance of glass-fiber-reinforced polymer (GFRP) bars is also changing, and some design codes are no longer applicable to new materials based on previous research results. In this study, a series of durability tests were carried out on a new generation of GFRP bars in laboratory-simulated seawater and a concrete environment under different temperatures and sustained loads. The durability performance of GFRP bars was investigated by analysing the residual tensile properties. The degradation mechanism of GFRP bars was also analysed by scanning electronic microscopy (SEM). Furthermore, the long-term performance of GFRP bars exposed to concrete pore solution under different stress levels was predicted using Arrhenius theory. The research results show that the degradation rate of GFRP bars was increased significantly at a 40% stress level. By comparing the test results, design limits, and other scholars' research results, it is demonstrated that the GFRP bars used in this test have a good durability performance. It is found that the main degradation mechanism of the GFRP bars is the debonding at the fiber-matrix interface. In the range test, the effects of a 20% stress level on the degradation of GFRP bars were not obvious. However, the long-term performance prediction results show that when the exposure time was long enough, the degradation processes were accelerated by a 20% stress level.
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The intestinal protozoan specie, Cryptosporidium causes serious diarrheal syndrome in humans and animals worldwide. However, limited knowledge is known about the infection caused by this specie in yaks in Naqu. About 950 serum and 150 fecal samples were collected and assayed by using commercial ELISA kits and nPCR detection methods to find the prevalence and molecular characterization of Cryptosporidium spp. in yaks. Results found that 103 out of 950 (10.8%) serums were uncovered against C. parvum antibodies. In different regions, the prevalence of C. parvum in yaks were in a range from 9.1% to 16.7%, with obvious difference among the three areas (P < 0.001). In male and female yaks, the prevalence of C. parvum was found to be 7.2% and 13.3% respectively (P < 0.001); and a significant difference (P < 0.001) with a range of 9.8%-18.2% was observed among different age groups. Out of 150 fecal samples, only 2 (1.3%) positive samples were detected via nPCR. The positive samples were sequenced and identified to be C. bovis. The two isolates were clustered to cattle and yak clade separately. Our results highlight the prevalence and epidemiological status of Cryptosporidium spp. in yaks which may contribute towards the prevention and control of this zoonotic disease in Naqu, China.
Subject(s)
Cattle Diseases/epidemiology , Cattle Diseases/microbiology , Cryptosporidiosis/epidemiology , Cryptosporidium/classification , Cryptosporidium/genetics , Animals , Cattle , China/epidemiology , Cryptosporidium/isolation & purification , Feces/microbiology , Female , Male , Phylogeny , Prevalence , Zoonoses/epidemiology , Zoonoses/microbiologyABSTRACT
Zika virus (ZIKV) infection of pregnant women can cause fetal microcephaly and other neurologic defects. We describe the development of a non-human primate model to better understand fetal pathogenesis. To reliably induce fetal infection at defined times, four pregnant rhesus macaques are inoculated intravenously and intraamniotically with ZIKV at gestational day (GD) 41, 50, 64, or 90, corresponding to first and second trimester of gestation. The GD41-inoculated animal, experiencing fetal death 7 days later, has high virus levels in fetal and placental tissues, implicating ZIKV as cause of death. The other three fetuses are carried to near term and euthanized; while none display gross microcephaly, all show ZIKV RNA in many tissues, especially in the brain, which exhibits calcifications and reduced neural precursor cells. Given that this model consistently recapitulates neurologic defects of human congenital Zika syndrome, it is highly relevant to unravel determinants of fetal neuropathogenesis and to explore interventions.
Subject(s)
Disease Models, Animal , Fetal Diseases/pathology , Macaca mulatta , Nervous System Diseases/pathology , Pregnancy Complications, Infectious/pathology , Zika Virus Infection/pathology , Zika Virus/pathogenicity , Animals , Brain/pathology , Brain/virology , Female , Fetal Diseases/virology , Fetus/pathology , Fetus/virology , Humans , Male , Nervous System Diseases/virology , Pregnancy , Pregnancy Complications, Infectious/virology , RNA, Viral/isolation & purification , Zika Virus/genetics , Zika Virus/isolation & purification , Zika Virus Infection/virologyABSTRACT
BACKGROUND: Because of the potential severe clinical consequences of Zika virus (ZIKV) infection, the large numbers of asymptomatic travelers returning from ZIKV-active areas, the detection of ZIKV nucleic acid in blood, and reports of transmission of ZIKV through transfusion, in 2016 the Food and Drug Administration released recommendations for individual-unit nucleic acid testing to minimize the risk of transmission of ZIKV through blood transfusions. METHODS: The American Red Cross implemented investigational screening of donated blood for ZIKV RNA by means of transcription-mediated amplification (TMA). Confirmatory testing of reactive donations involved repeat TMA, TMA testing in exploratory minipools, real-time reverse-transcriptase polymerase chain reaction, IgM serologic testing, and red-cell TMA. Viral loads in plasma and red cells were estimated by means of end-point TMA. The costs of interdicting a donation that was confirmed to be positive were calculated for the 15-month period between June 2016 and September 2017. RESULTS: Of the 4,325,889 donations that were screened, 393,713 (9%) were initially tested in 24,611 minipools, and no reactive donations were found. Of the 3,932,176 donations that were subsequently tested individually, 160 were initially reactive and 9 were confirmed positive (a 1:480,654 confirmed-positive rate overall; positive predictive value, 5.6%; specificity, 99.997%). Six (67%) of the confirmed-positive donations were reactive on repeat TMA, of which 4 were IgM-negative; of these 4, all 3 that could be tested were reactive on minipool TMA. Two confirmed-positive donors had infections that had been transmitted locally (in Florida), 6 had traveled to ZIKV-active areas, and 1 had received an experimental ZIKV vaccine. ZIKV RNA levels in red cells ranged from 40 to 800,000 copies per milliliter and were detected up to 154 days after donation, as compared with 80 days of detection in plasma at levels of 12 to 20,000 copies per milliliter. On the basis of industry-reported costs of testing and the yield of the tests in our study, the cost of identifying 8 mosquito-borne ZIKV infections through individual-unit nucleic acid testing was $5.3 million per ZIKV RNA-positive donation. CONCLUSIONS: Screening of U.S. blood donations for ZIKV by individual-donation TMA was costly and had a low yield. Among the 9 confirmed ZIKV-positive donations, only 4 were IgM-negative; of these donations, all 3 that were tested were reactive on minipool TMA. (Funded by the American Red Cross and Grifols Diagnostic Solutions.).
Subject(s)
Blood Donors , Blood/virology , Cost-Benefit Analysis , Mass Screening/economics , Zika Virus Infection/diagnosis , Zika Virus/isolation & purification , Adult , Aged , Female , Humans , Immunoglobulin M/blood , Male , Middle Aged , Nucleic Acid Amplification Techniques , RNA, Viral/blood , Red Cross , Sensitivity and Specificity , United States/epidemiology , Viral Load , Young Adult , Zika Virus/genetics , Zika Virus/immunology , Zika Virus Infection/epidemiology , Zika Virus Infection/virologyABSTRACT
A Zika virus disease outbreak occurred in Roatán, Honduras, during September 2015-July 2016. Blood samples and clinical information were obtained from 183 patients given a clinical diagnosis of suspected dengue virus infection. A total of 79 patients were positive for Zika virus, 13 for chikungunya virus, and 6 for dengue virus.