ABSTRACT
BACKGROUND: This study aims to explore the characteristics of the epithelial-to-mesenchymal transition (EMT) process and its underlying molecular mechanisms in the period of paraquat (PQ)-induced pulmonary fibrosis (PF). METHODS: Picrosirius red staining and collagen volume fraction were utilized to evaluate the pathological changes of PQ-induced PF in rats. Immunohistochemistry, Western blot, and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) were used to measure the protein and gene expression of EMT markers, EMT-associated transcription factors, and regulators of EMT-related pathways, respectively. RESULTS: The collagen deposition in the alveolar septum and increased PF markers were characteristics of pathological changes in PQ-induced PF, reached a peak on day 14 after PQ poisoning, and then decreased on day 21. The protein and gene expression of the fibrosis marker, EMT markers, transcription factors, and regulators of EMT-related signaling pathways significantly increased at different time points after PQ poisoning compared with corresponding controls (P<0.05), and most of them reached a peak on day 14, followed by a decrease on day 21. The gene expression of EMT markers was significantly correlated with PF markers, transcription factors, and regulators of EMT-related signaling pathways (P<0.05). The mRNA expression of transcription factors was significantly correlated with that of TGF-ß1 and Smad2 (P<0.05 or P<0.01), instead of Wnt2 and ß-catenin (P>0.05). CONCLUSIONS: EMT process plays a role in the PQ-induced PF, in which most PF and EMT markers have a peak phenomenon, and its underlying molecular mechanisms might be determined by further studies.
ABSTRACT
This study evaluated the effects of the transplantation of a tissue-engineered nerve derived from an acellular allogenic nerve graft, combined with autologous bone marrow stromal cells (MSCs), into peripheral nerve defects. In a rhesus monkey model, nerve regeneration was evaluated across a 1-cm lesion in the radial nerve by using an acellular allogenic nerve injected with autologous MSCs. Simple acellular nerve allografts served as control. Eight weeks after surgery, immunofluorescence staining, histologic morphometrical analysis and electrophysiologic evaluation were performed. Fluorescence microscopy revealed that some MSCs were immunopositive to S-100 protein, indicating a Schwann cell (SC) phenotype. The group treated with cultured MSCs showed a statistically higher number of nerve fibers, with well-shaped remyelinated axons. The motor conduction velocities and the peak amplitudes of compound muscle action potentials (CMAP) for the group treated with MSCs were higher than those of the controls. This outcome indicated that MSCs are able to differentiate into Schwann-like cells in vivo and to promote nerve regeneration in primates. Furthermore, the acellular nerves injected with MSCs provided a favorable environment for the growth and myelination of regenerating axons when compared to acellular nerves alone.
Subject(s)
Bone Marrow Transplantation/methods , Nerve Regeneration/physiology , Peripheral Nerve Injuries , Peripheral Nerves/transplantation , Stem Cell Transplantation/methods , Stromal Cells/transplantation , Action Potentials/physiology , Animals , Biomarkers/analysis , Biomarkers/metabolism , Cell Culture Techniques/methods , Cell Differentiation/physiology , Cells, Cultured , Culture Media/pharmacology , Disease Models, Animal , Fluorescent Antibody Technique , Growth Cones/physiology , Growth Cones/ultrastructure , Macaca mulatta , Male , Microscopy, Electron, Transmission , Neural Conduction/physiology , Peripheral Nerves/physiology , Radial Nerve/physiology , Radial Nerve/surgery , Radial Nerve/ultrastructure , S100 Proteins/analysis , S100 Proteins/metabolism , Schwann Cells/metabolism , Schwann Cells/ultrastructure , Stromal Cells/physiology , Stromal Cells/ultrastructure , Transplantation, Homologous/methodsABSTRACT
A new high nitrogen compound hydrazine 3-nitro-1,2,4-triazol-5-one complex (HNTO) was prepared by the reaction of 3-nitro-1,2,4-triazol-5-one with hydrazine hydrate, and its structure was characterized by means of organic elemental analyzer, FT-IR, XRD, (13)C NMR and (15)N NMR. The non-isothermal reaction kinetics of the main exothermic decomposition reaction of HNTO was investigated by means of DSC. The thermodynamic properties of HNTO were calculated. The results showed that the formation of HNTO is achieved by proton transfer of N(4) atom, and it makes a higher nitrogen content and lower acidity. The reaction mechanism of HNTO is classified as nucleation and growth, and the mechanism function is Avramo-Erofeev equation with n=2/5. The kinetic parameters of the reaction are E(a)=195.29 kJ mol(-1), lg(A (s(-1)))=19.37, respectively. The kinetic equation can be expressed as: d(alpha)/d(t) = 10(18.97)(1 - alpha)[-ln(1 - alpha)](3/5) e(-2.35 x 10(4)/T). The safety performances of HNTO were carried out. The critical temperature of thermal explosion are 464.26 and 474.37 K, the adiabatic time-to-explosion is 262s, the impact sensitivity H(50)=45.7 cm, the friction sensitivity P=20% and the electrostatic spark sensitivity E(50)>5.4J (no ignition). It shows that HNTO has an insensitive nature as RDX and NTO, etc.
Subject(s)
Explosive Agents/chemistry , Hydrazines/chemistry , Nitro Compounds/chemistry , Triazoles/chemistry , Calorimetry, Differential Scanning , Explosions , Kinetics , Magnetic Resonance Spectroscopy , Temperature , Thermodynamics , X-Ray DiffractionABSTRACT
Effects of fullerene soot (FS) on the thermal decomposition and Fourier transform infrared spectrum (FTIR) of polyethylene glycol (PEG, molecular weight= 20,000) were investigated by thermal analysis (TG-DTG) and in-situ FTIR experiments. The results of thermal analytical experiments showed that the addition of FS postponed not only the initial decomposition temperatures but also the temperatures at maximum decomposition rate of PEG. The maximum decomposition peak temperatures increased and the maximum decomposition rates were lowered even with the addition of 0.1%FS. The in-situ FTIR experiments proved that there was no difference between the IR spectra of PEG and PEG with 10%FS. There wasn't any new chemical band formed but Vander waals force between FS and PEG. Although the addition of FS didn't influence the constitution of decomposition products of PEG, it obviously increased the decomposition temperature and the decomposition rate of PEG. Through the researches on condensed phase and gaseous phase FTIR spectrum of PEG and PEG with 10%FS, one could see that the effect of FS on the condensed phase FTIR spectrum of PEG was not obvious, but the addition of FS markedly enhanced the occurrence temperatures of most gaseous decomposition products of PEG. These results showed that the effect of FS on thermal decomposition of PEG was through the absorbance and desorption of gaseous phase decomposition products. With the temperature elevated, the gaseous products were gradually desorbed from the activity centers and the decomposition of PEG continued. The thermal decomposition peak of PEG was moved toward hi gher temperature with the addition of FS than that without FS.
Subject(s)
Fullerenes/chemistry , Polyethylene Glycols/chemistry , Spectroscopy, Fourier Transform Infrared/methods , TemperatureABSTRACT
Hepatitis B virus X (HBx) protein plays a pivotal role in the development of hepatitis B virus (HBV)-associated hepatocellular carcinoma. Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein, the mechanism of HBx protein regulating intracellular calcium level remains poorly understood. The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry (SOCE) components, Orail and stromal interaction molecule 1, and then identified the targets of HBx protein, with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis. By employing co-immunoprecipitation and GST-pull-down assay, we found that Orail protein interacted with HBx protein, and the C-terminus of Orail was implicated in the interaction. Confocal microscopy also revealed that HBx protein could co-localize with full-length Orail protein in HEK293 cells. Moreover, live cell calcium imaging exhibited that HBx protein elevated intracellular calcium, possibly by binding to SOCE components. Our results suggest that HBx protein binds to STIM1-Orail complexes to positively regulate the activity of plasma membrane store-operated calcium channels.
Subject(s)
Calcium Signaling , ORAI1 Protein/metabolism , Trans-Activators/metabolism , Binding Sites , HEK293 Cells , Hep G2 Cells , Humans , ORAI1 Protein/chemistry , Protein Binding , Up-Regulation , Viral Regulatory and Accessory ProteinsABSTRACT
OBJECTIVE: To investigate the protective effects of paeoniflorin against PM2.5-induced damage in BEAS-2B cells and explore the possible mechanism. METHODS: With a factorial design, this study was performed to observe the protective effects of different doses of paeoniflorin against PM2.5-induced BEAS-2B cell growth inhibition and the effects of paeoniflorin on the contents of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS) in the cell cultures. RESULTS: Exposure to increased PM2.5 concentrations caused significant decrease in the cell survival rate (P<0.05) with a clear dose-response relationship (r=-0.759, P<0.05). Treatment of the cells with paeoniflorin significantly attenuated PM2.5-induced inhibition of BEAS-2B cell survival (P<0.05), but the effect of paeoniflorin was not dose-dependent (P>0.05). PM2.5 exposure also significantly increased the contents of MDA and intracellular ROS (P<0.05), and paeoniflorin obviously antagonized these effects of PM2.5. CONCLUSION: Paeoniflorin can protect BEAS-2B cells from PM2.5-induced growth inhibition, and the mechanism might be related to the anti-oxidant effects of paeoniflorin.
Subject(s)
Epithelial Cells/drug effects , Glucosides/pharmacology , Monoterpenes/pharmacology , Particulate Matter/adverse effects , Antioxidants/pharmacology , Cell Line , Cell Survival , Humans , Malondialdehyde/metabolism , Reactive Oxygen Species/metabolismABSTRACT
OBJECTIVE: To screen for serum biomarkers of silicosis and to study their roles using surface-enhanced laser desorption ionization time-of-fly mass spectrometry (SELDI-TOF-MS) techniques. METHODS: The serum protein/peptide profile on the CM10 proteinchip was acquired using SELDI-TOF-MS from workers classified by the Chinese national diagnostic standard for pneumoconiosis. Discriminant analysis was performed to establish a decision tree using protein/peptide peaks. RESULTS: Protein/peptide peaks changed much more in silica-exposed populations than they did in the control. Discriminant analysis using Wilks' lambda method could give high sensitivity and specificity in distinguishing the silica-exposed population from the control; the decision tree could give 100% sensitivity and 95% specificity in distinguishing the silicosis phase among the control group. CONCLUSIONS: Special proteins/peptides may change in silica-exposed workers and these changes may be used to distinguish silica-exposed populations from the control with the proper discriminant analytical method.
Subject(s)
Biomarkers/blood , Decision Trees , Mass Screening , Silicosis/diagnosis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , China , Discriminant Analysis , Humans , Male , Peptides/analysis , Peptides/blood , Silicosis/blood , Silicosis/physiopathologyABSTRACT
OBJECTIVE: To investigate risk factors affecting the survival rate in serious multiple traumatic patients associated with acute lung injure (ALI)/acute respiratory distress syndrome (ARDS). METHODS: The clinical data of 76 serious multiple trauma patients associated with ALI and 95 cases in ARDS, totally 171 patients associated with ALI/ARDS, were retrospectively studied, and stepwise logistic regression analysis was used to analyze 20 possible risk factors affecting survival rate. RESULTS: The risk factors affecting survival rate in the ALI group: included smoking (B = -5.235, OR = 0.005, P = 0.001), sepsis secondary to trauma (B = -2.753, OR = 0.064, P = 0.031), and gastrointestinal hemorrhage (B = -2.876, OR = 0.056, P = 0.033). The risk factors affecting survival rate in the ARDS group included the time of induction factor persisting to attacking (B = 3.524, OR = 33.933, P = 0.008), sepsis secondary to trauma (B = -5.183, OR = 0.006, P = 0.004); renal insufficiency(B = -4.745, OR = 0.009, P = 0.009), and gastrointestinal hemorrhage (B = -6.335, OR = 0.002, P = 0.007). CONCLUSION: Different from the results of study of traditional risk factors affecting survival rate in ALI/ARDS, this study reveals that smoking may be an independent risk factor; the earlier ALI/ARDS appears, the lower the predictable survival rate in condition of serious multiple trauma; MODS is easily induced in the course of complicating renal insufficiency during the time of lung injury; sepsis and gastrointestinal hemorrhage are still the infective factors or infection inducing factors affecting the survival rate after trauma; and the primary disease causing infection must be treated actively.
Subject(s)
Lung Diseases/complications , Multiple Trauma/complications , Respiratory Distress Syndrome/complications , Acute Disease , Adult , Female , Gastrointestinal Hemorrhage/etiology , Gastrointestinal Hemorrhage/mortality , Humans , Injury Severity Score , Logistic Models , Lung Diseases/mortality , Male , Multiple Trauma/mortality , Respiratory Distress Syndrome/mortality , Retrospective Studies , Risk Factors , Sepsis/etiology , Sepsis/mortality , Smoking/adverse effects , Survival RateABSTRACT
OBJECTIVE: To investigate the effect of low-selenium diet on the liver and kidneys of rats and explore the role of macrophage polarization into M1 and M2 phenotypes in liver and kidney injuries. METHODS: Twenty-four rats (12 female and 12 male) were randomly divided into control group and low-selenium group and fed with normal chow (dietary selenium of 0.18 mg/kg) and low-selenium diet (dietary selenium of 0.02 mg/kg) for 109 days. After the feeding, the rats were sacrificed for HE staining to observe liver and kidney pathologies, and immunohistochemistry was performed for analyzing CCR7, CD206, CD163-positive cell numbers in the liver and kidneys. RESULTS: The rats in low-selenium group showed severer fibrosis in the liver and kidney than the control group. In either male or female rats in low-selenium group, CCR7 and CD206 expressions in the liver were comparable with those in control group, but CD163 expression was lower than that in the control group (P<0.05 for both female and male rats). In the kidney, the proximal tubule showed a slightly higher while the distal tubule showed a slightly lower CCR7 expression in low selenium group than in the control group (P>0.05). In low-selenium group, a significantly lower CD163 expression in the distal tubule and a significantly higher CD206 expression in the proximal tubule were noted as compared with the control group (P<0.05 in both female and male rats). Compared with the control rats, the male rats in low-selenium group, but not the female rats, showed a significantly lower CD163 expression in the proximal tubule of the kidney (P<0.05); the female but not the male rats in low-selenium group show a higher CD206 expression in the distal tubule (P<0.05). CONCLUSION: Low-selenium diet can cause liver and kidney fibrosis in rats and may inhibit macrophage activation into the M2 phenotype.
Subject(s)
Diet , Kidney/metabolism , Liver/metabolism , Macrophage Activation , Selenium/administration & dosage , Animals , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Female , Fibrosis , Kidney/pathology , Lectins, C-Type/metabolism , Liver/pathology , Male , Mannose Receptor , Mannose-Binding Lectins/metabolism , Rats , Receptors, CCR7/metabolism , Receptors, Cell Surface/metabolismABSTRACT
OBJECTIVE: To investigate the relationship between the expression of COX-2 and liver cancer and construct a recombinant adenovirus encoding human COX-2 antisense RNA, and then to investigate its effects on liver cancer cell proliferation. METHODS: The expression of COX-2 in 34 cases of hepatocellular carcinoma and in SMMC-7402 and SMMC-7721 cell lines was studied by using immunohistochemical techniques. The shuttle plasmid encoding anti-sense COX-2 was constructed by using cloning COX-2 cDNA fragment in the reverse direction into the pHCMVSPIA. Then the plasmid pJM17 and the shuttle plasmid were co-transferred into 293 cells with lipofectamine for homologous recombination to acquire recombinant adenovirus (Ad-AShcox-2), which was confirmed by PCR. Human hepatocellular carcinoma cell lines SMMC-7402 and SMMC-7721 were transduced in vitro. The cell apoptosis and cell cycle were analyzed by flow cytometry. The cell proliferation was determined by colony-forming efficiency. RESULTS: We observed COX-2 expression in 82.4% of the hepatocellular carcinomas and SMMC-7402 cell line, but no COX-2 expression in the SMMC-7721 cell line. In addition, the recombinant adenovirus encoding anti-sense COX-2 fragment Ad-AShcox-2 was obtained with a titer of 1.06 x 10(12) PFU/ml. Ad-AShcox-2 reduced the expression of COX-2 and enhanced the percentage of cells into G1/G0 phase in the SMMC-7402 cell line. The difference of apoptotic index between the Ad-AShcox-2 group and the control group was statistically significant in SMMC-7402 but not in SMMC-7721. Similarly, colony-forming rates of SMMC-7402 and SMMC-7721 cell lines after Ad-AShcox-2 being transferred were (2.7+/-0.94)% and (33.6+/-4.24)%, respectively. CONCLUSION: By reducing the expression of COX-2 in hepatocellular carcinoma cells with the expression of COX-2, the cells could be inhibited.
Subject(s)
Adenoviridae/genetics , Carcinoma, Hepatocellular/pathology , Cyclooxygenase 2/biosynthesis , Liver Neoplasms/pathology , Membrane Proteins/biosynthesis , RNA, Antisense/biosynthesis , Apoptosis/physiology , Cell Line, Tumor , Cell Proliferation , Cyclooxygenase 2/genetics , Humans , Membrane Proteins/genetics , RNA, Antisense/geneticsABSTRACT
BACKGROUND: Osteochondroma is the most common benign bone tumor of the upper limbs that occurs during the developmental phase of children. Solitary epiphyseal enchondromas can be usually found in the humeral capitellum, and the proximal ulna of the elbow. CASE PRESENTATION: Herein, we report the case of a 12-year-old boy of Han ethnicity with a developmental radial head dislocation with a progressive radius deformities, caused by a solitary osteochondroma which originated from the proximal metaphysis of the radius. Obvious complaints and limitations were present. After tumor excision was performed, radial head reduction and deformity correction were achieved through a biplanar shortening osteotomy of the radius. CONCLUSIONS: After a follow-up of 18 months, the child remained asymptomatic and regained a full range of motion. Radiographic study revealed satisfactory reduction of the radial head with no recurrence of the osteochondroma.
Subject(s)
Bone Neoplasms/pathology , Elbow Joint/abnormalities , Joint Dislocations/pathology , Osteochondroma/pathology , Radius/abnormalities , Upper Extremity Deformities, Congenital/pathology , Bone Neoplasms/complications , Bone Neoplasms/diagnostic imaging , Bone Neoplasms/surgery , Child , Elbow Joint/diagnostic imaging , Elbow Joint/surgery , Humans , Joint Dislocations/diagnostic imaging , Joint Dislocations/etiology , Joint Dislocations/surgery , Male , Osteochondroma/complications , Osteochondroma/diagnostic imaging , Osteochondroma/surgery , Osteotomy , Radiography , Radius/diagnostic imaging , Radius/surgery , Range of Motion, Articular , Recovery of Function , Upper Extremity Deformities, Congenital/complications , Upper Extremity Deformities, Congenital/diagnostic imaging , Upper Extremity Deformities, Congenital/surgeryABSTRACT
OBJECTIVE: To study the changes of the contralateral testicular histology and germ cell apoptosis after unilateral testicular torsion (UTT) and to determine whether the contralateral testis is injured or not. METHODS: Sixty SD male rats were divided into control group (12 rats) and experimental group(48 rats). The former underwent sham operation of the left testis under general anaesthesia. The latter underwent left testis torsion(720 degrees) for 6 h, and then 4 of them were sacrificed and the other 44 were subdivided into the torsed testis untwisted group (22 rats) and the torsed testis removal group (22 rats), 7-8 rats were sacrificed and both testes (twisted and untwisted) were removed 1 day, 1 week and 4 weeks after surgery. All testes underwent histological and germ cell apoptosis examination. RESULTS: There were significant histological changes in the contralateral testis, and the germ cell apoptosis was increased greatly in the contralateral testis. CONCLUSIONS: UTT can cause contralateral testicular injury, whose mechanism may be related to reperfusion, and torsed testis removal can prevent or reduce damage to the contralateral testis.
Subject(s)
Germ Cells/pathology , Spermatic Cord Torsion/pathology , Testis/pathology , Animals , Apoptosis , Male , Random Allocation , Rats , Rats, Sprague-Dawley , Reperfusion Injury/pathologyABSTRACT
BACKGROUND: Osteosarcoma is the most common primary bone cancer in growing adolescents and young adults. The prognostic role of C-reactive protein (CRP) in patients with osteosarcoma is not fully investigated. The purpose of this study is to perform a meta-analysis and literature review on the role of CRP in osteosarcoma and to assess the potential role of serum CRP as a prognostic factor for patients with osteosarcoma. METHODS: A detailed literature search was made in Medline for related research publications written in English. Methodological quality of the studies was also evaluated. The data were extracted and assessed by two reviewers independently. Analysis of pooled data were performed, risk ratio (RR) and corresponding confidence intervals (CIs) were calculated and summarized respectively. RESULTS: Final analysis of 397 patients from 2 eligible studies was performed. Combined RR of CRP expression suggested that the raised serum CRP level had an adverse prognostic effect on overall survival of patients with osteosarcoma (n = 397 in 2 studies; RR = 0.35; 95% CI: 0.18-0.68; p = 0.002). In the uni- and multivariate survival analysis, response rate and CRP levels were the only independent prognostic variables. CONCLUSIONS: The results of this meta-analysis suggest that CRP expression confers a worse prognosis in patients with osteosarcoma. Large prospective studies are necessary to provide solid data to confirm the prognostic significance of CRP.
Subject(s)
Biomarkers, Tumor/metabolism , C-Reactive Protein/metabolism , Osteosarcoma/blood , HumansABSTRACT
OBJECTIVE: To evaluate the efficacy and safety of the treatment of traumatic hemothorax by closed pleural drainage using a central venous catheter (CVC), compared with using a conventional chest tube. METHODS: A prospective controlled study with the Ethics Committee approval was undertaken. A total of 407 patients with traumatic hemothorax were involved and they were randomly assigned to undergo closed pleural drainage with CVCs (n=214) or conventional chest tubes (n=193). The Seldinger technique was used for drainage by CVC, and the conventional technique for drainage by chest tube. If the residual volume of the hemothorax was less than 200 ml after the daily volume of drainage decreased to below 100 ml for two consecutive days, the treatment was considered successful. The correlative data of efficacy and safety between the two groups were analyzed using t or chi-squared tests with SPSS 13.0. A P value of less than 0.05 was taken as indicating statistical significance. RESULTS: Compared with the chest tube group, the operation time, fraction of analgesic treatment, time of surgical wound healing, and infection rate of surgical wounds were significantly decreased (P<0.05) in the CVC group. There were no significant differences between the two groups in the success rate of treatment and the incidence of serious complications (P>0.05), or in the mean catheter/tube indwelling time and mean medical costs of patients treated successfully (P>0.05). CONCLUSIONS: Management of medium or large traumatic hemothoraxes by closed thoracic drainage using CVC is minimally invasive and as effective as using a conventional large-bore chest tube. Its complications can be prevented and it has the potential to replace the large-bore chest tube.
Subject(s)
Catheterization, Central Venous/methods , Hemothorax/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Catheterization, Central Venous/standards , Chi-Square Distribution , Drainage/instrumentation , Drainage/methods , Female , Humans , Male , Middle Aged , Prospective Studies , Young AdultABSTRACT
A total of 118 patients with schistosomal hepatocirrhosis were divided into an experiment group (62 cases) and a control group (56 cases), and the former received capsule Xinganbao and the latter received conventional medicine for 6 months. The reductions of serum HA, LN and PCIII were more notable in the experiment group than in the control group (P < 0.05). The clinical symptoms, physical signs, and liver function improved in both groups, and there were no significant differences between two groups. In conclusions, capsule Xinganbao has a good effect on hepatic fibrosis.
Subject(s)
Drugs, Chinese Herbal/administration & dosage , Liver Cirrhosis/drug therapy , Schistosomiasis/drug therapy , Adult , Aged , Capsules , Female , Humans , Liver Cirrhosis/complications , Male , Middle Aged , Phytotherapy , Schistosomiasis/complications , Treatment OutcomeABSTRACT
Aimed to explore the ecological reasons for the difference in nicotine content of flue-cured tobacco planted in different regions of Hunan Province, field experiments were conducted in Sangzhi, Liuyang, and Yongzhou counties, the three typical tobacco regions of Hunan Province, taking tobacco variety K326 as the test object. Simultaneously, pot experiments with local soils and guest soils were carried out. The nicotine content of mid position tobacco leaves was analyzed at harvest time. Field experiments showed that the average nicotine content of tobacco leaves differed significantly among test sites, with that in Sangzhi being the highest, followed by Liuyang, and Yongzhou. Pot experiments showed that climate had significant effects on the average nicotine content of tobacco leaves, while soil and its interaction with climate had less effects. The contribution rate of climate, soil, and their interaction on the variance of the average nicotine content was 60.0%, 12.8% and 27.2%, respectively. The main sub-ecological factors closely related to the average nicotine content of flue-cured tobacco planted in different regions of Hunan Province were in turn the cloud cover at maturing stage, the relative humidity, sunshine hours, diurnal temperature variance, and rainfall at root-extending stage, and the average air temperature at vigorous growth stage. Generally, climate was the main ecological factor that led to the nicotine content difference of flue-cured tobacco planted in different regions of Hunan Province.
Subject(s)
Ecosystem , Nicotiana/chemistry , Nicotiana/growth & development , Nicotine/analysis , Soil/analysis , China , GeographyABSTRACT
A bismuth 3-nitro-1,2,4-triazol-5-one (Bi-NTO) complex was prepared and characterized, and its effects on the thermal behaviors, non-isothermal decomposition reaction kinetics, and burning rates of the double-base (DB) propellant containing the mixed ester of triethyleneglycol dinitrate (TEGDN) and nitroglycerin (NG) with Bi-NTO complex as a ballistic modifier were investigated by thermogravimetry and derivative thermogravimetry (TG-DTG), and differential scanning calorimetry (DSC). The results show that Bi-NTO complex can increase the decomposition heat by 140 J g(-1), and it can change the decomposition reaction mechanism function, the kinetic parameters and kinetic equation of the propellant under 0.1 MPa. Combustion experiment shows that Bi-NTO complex can increase the burning rate and reduce the pressure exponent of the NG/TEGDN/NC propellant effectively, with the increase of the catalysis efficiency by 40%.
Subject(s)
Incineration , Nitro Compounds/chemistry , Thermodynamics , Triazoles/chemistry , Bismuth , Calorimetry, Differential Scanning , Kinetics , Nitrates/chemistry , Nitroglycerin/chemistry , Temperature , ThermogravimetryABSTRACT
A pot experiment with the soils from Yongzhou, Liuyang, and Sangzhi, the high-quality tobacco planting regions of Hunan Province, was conducted to study the effects of climate, soil, and their interaction on some neutral volatile aroma components in flue-cured tobacco leaves. The contents of test neutral volatile aroma components in the flue-cured tobacco leaves were of medium variation, and the variation intensity was decreased in the order of dihydroactinolide, damascenone, furfural, total megastigmatrienone, and beta-ionone. Climate, soil, and their interaction affected the neutral volatile aroma components in different degrees. The furfural content was most affected by climate, the damascenone content was most affected by climate and by soil, the total megastigmatrienone and beta-ionone contents were most affected by the interaction of soil and climate, while the dihydroactinolide content was less affected by soil, climate, and their interaction. The contribution of climate, soil, and their interaction to the contents of the five aroma components was 40.82%, 20.67%, and 38.51%, respectively. During different growth periods of tobacco, different climate factors had different effects on the neutral volatile aroma components. The rainfall, cloudiness, and mean air temperature at rooting stage, the diurnal temperature amplitude, sunshine time, and evaporation at vigorous growth stage, and the rainfall, evaporation, and mean air temperature at maturing stage were the top three climate factors affecting the contents of the neutral volatile aroma components in flue-tobacco leaves. For the soil factors, the available potassium, available phosphorus, and pH were the top three factors affecting the contents of the five components.
Subject(s)
Climate , Nicotiana/chemistry , Odorants/analysis , Plant Leaves/chemistry , Soil/analysis , Alkenes/analysis , China , Cyclohexanes/analysis , Cyclohexanones/analysis , Furaldehyde/analysis , Quality Control , VolatilizationABSTRACT
In this study, we aimed to evaluate the potential of tissue-engineered nerve grafts created from acellular allogenic nerve tissues combined with autologous bone marrow stromal cells (BMSCs) for repairing large peripheral nerve lesions. In a rhesus monkey model, a 2.5-cm-long gap was created in the radial nerve, followed by implantation of either autografts or acellular allografts seeded with autologous BMSCs, Schwann cells (SCs), or no cells. Five months after surgery nerve regeneration was assessed functionally, electrophysiologically, and histomorphometrically. Compared to non-cell-laden allografts, BMSC-laden allografts remarkably facilitated the recovery of the grasping functions of the animals. This functional improvement was coupled with increased nerve conduction velocities and peak amplitudes of compound motor action potentials, and greater axon growth, as well as higher target muscle weight. Moreover, the intensities of nerve regeneration in the BMSC-laden group were comparable to those achieved with SC-laden allografts and autografts. Our data highlight the potential of BMSC-seed allografts for the repair of long peripheral nerve lesions, and reveal comparable regeneration intensities achieved by BMSC-, and SC-laden allografts, as well as autografts. Given their wide availability, BMSCs may represent a promising cell source for tissue-engineered nerve grafts.
Subject(s)
Bone Marrow Transplantation , Nerve Regeneration/physiology , Radial Nerve/physiopathology , Schwann Cells/transplantation , Stromal Cells/transplantation , Action Potentials/physiology , Analysis of Variance , Animals , Bone Marrow Cells/physiology , Electrophysiology , Hand Strength/physiology , Macaca mulatta , Male , Recovery of Function , Schwann Cells/physiology , Stromal Cells/physiology , Transplantation, HomologousABSTRACT
The composite modified double base (CMDB) propellants (nos. RB0601 and RB0602) containing 3,6-bis (1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz) without and with the ballistic modifier were prepared and their thermal behaviors, nonisothermal decomposition reaction kinetics, thermal safety and burning rates were investigated. The results show that there are three mass-loss stages in TG curve and two exothermic peaks in DSC curve for the BTATz-CMDB propellant. The first two mass-loss stages occur in succession and the temperature ranges are near apart, and the decomposition peaks of the two stages overlap each other, inducing only one visible exothermic peak appear in DSC curve during 350-550 K. The reaction mechanisms of the main exothermal decomposition processes of RB0601 and RB0602 are all classified as chemical reaction, the mechanism functions are f(alpha)=(1-alpha)(2), and the kinetic equations are dalpha/dt = 10(19.24)(1-alpha)(2)e(-2.32x10(4)/T) and dalpha/dt = 10(20.32)(1-alpha)(2)e(-2.32x10(4)/T). The thermal safety evaluation on the BTATz-CMDB propellants was obtained. With the substitution of 26% RDX by BTATz and with the help of the ballistic modifier in the CMDB propellant formulation, the burning rate can be improved by 89.0% at 8 MPa and 47.1% at 22 MPa, the pressure exponent can be reduced to 0.353 at 14-20 MPa.