The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound st...The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered compound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.展开更多
The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine...The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.展开更多
In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of pa...In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of parasite egg colors and markings in detection cues in hosts;however,studies focusing on the effects of egg size and quantity are relatively scarce and have mostly concentrated on the hosts of parasitic cowbirds.Here,we studied the egg recognition behaviors of a potential host of the Common Cuckoo(Cuculus canorus)—the Green-backed Tit(Parus monticolus),to determine:(1)whether the host uses the sizes of parasite eggs and/or the quantity contrast between parasite and host eggs as cues for recognition,(2)whether the host employs the template or discordant recognition mechanism for egg recognition,and(3)whether the size and quantity of parasite eggs affect the egg rejection modes of the hosts.The results indicate that Green-backed Tits did not use parasite egg size as a primary cue for egg recognition.We hypothesized that both visual and tactile detection might be involved in egg recognition by Green-backed Tits and suggest further studies after controlling for nest light conditions.Differences in egg quantity between parasites and hosts were not used as cues for egg recognition because the hosts employed the template mechanism rather than discordance to recognize parasite eggs.However,both the relative sizes and quantity of parasite and host eggs significantly affected the rejection modes of parasite eggs,and larger or more parasite eggs triggered higher probabilities of nest desertion in hosts.展开更多
Background Arterial stiffness and homocysteine are both powerful predictors of cardiovascular disease, especially in older popula tions. Previous studies have investigated the association of homocysteine with arterial...Background Arterial stiffness and homocysteine are both powerful predictors of cardiovascular disease, especially in older popula tions. Previous studies have investigated the association of homocysteine with arterial stiffness in human subjects, while the relationship between homocysteine and arterial stiffness in the elderly is still indefinite. The current study examined the association of homocysteine with arterial stiffness in Chinese community-based elderly persons. Methods We related serum levels of homocysteine to two measures of arte- rial stiffness （carotid-femoral pulse wave velocity （PWV） and carotid-radial PWV） in 780 participants （46.3% men, mean age 71.9 years （ranging 65-96 years old）） from two communities of Beijing, China. Arterial stiffness were measured within two days of the time of bio- marker measurement. Results In multiple-adjusted models, homocysteine levels was strongly associated with the carotid-femoral PWV （standardized 13 = 0.13, P 〈 0.001）, even after adjustment for classical risk factors of cardiovascular disease. The association is also stronger when the carotid-femoral PWV is elevated above normal, whereas no significant association with homocysteine was observed for ca-rotid-radial PWV. Conclusions In Chinese elderly persons, serum homocysteine levels are associated with alterations of aortic stiffness.展开更多
Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodont...Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.展开更多
Hepatitis B virus(HBV)infection is a global public health problem that causes persistent liver diseases such as chronic hepatitis,cirrhosis,and hepatocellular carcinoma.A large amount of people die annually from HBV i...Hepatitis B virus(HBV)infection is a global public health problem that causes persistent liver diseases such as chronic hepatitis,cirrhosis,and hepatocellular carcinoma.A large amount of people die annually from HBV infection.However,the pathogenesises of the HBV-related diseases are ill defined and the therapeutic strategies for the diseases are less than optimum.The recently discovered microRNAs(miRNAs)are tiny noncoding RNAs that regulate gene expression primarily at the post-transcriptional level by binding to mRNAs.miRNAs contribute to a variety of physiological and pathological processes.A number of miRNAs have been found to play a pivotal role in the host-virus interaction including host-HBV interaction.Numerous studies have indicated that HBV infection could change the cellular miRNA expression patterns and different stages of HBV associated disease have displayed distinctive miRNA profiles.Furthermore,the differential expressed miRNAs have been found involved in the progression of HBV-related diseases,for instance some miRNAs are involved in liver tumorigenesis and tumor metastasis.Studies have also shown that the circulating miRNA in serum or plasma might be a very useful biomarker for the diagnosis and prognosis of HBV-related diseases.In addition,miRNA-based therapy strategies have attracted increasing attention,indicating a promising future in the treatment of HBV-related diseases.展开更多
Objective To investigate the effect of peroxisome proliferator-activated receptor-α(PPARα)and PPARγactivators on tumor necrosis factor-α(TNFα)expression in neonatal rat cardiac myocytes.Methods Primary cultures o...Objective To investigate the effect of peroxisome proliferator-activated receptor-α(PPARα)and PPARγactivators on tumor necrosis factor-α(TNFα)expression in neonatal rat cardiac myocytes.Methods Primary cultures of cardiac myocytes from 1-to 3-day-old Wistar rats were prepared,and myocytes were ex-posed to lipopolysaccharide(LPS)and varying concentrations of PPARαor PPARγactivator(fenofibrate or pioglitazone).RT-PCR and ELISA were used to measure TNFα,PPARα,and PPARγexpression in cultured cardiac myocytes.Transient tr-ansfection of TNFαpromoter with or without nuclear factor-kappaB(NF-κB)binding site to cardiac myocytes was performed.Results Pretreatment of cardiac myocytes with fenofibrate or pioglitazone inhibited LPS-induced TNFαmRNA and protein expression in a dose-dependent manner.However,no significant changes were observed on PPARαor PPARγmRNA expression when cardiac myocytes were pretreated with fenofibrate or pioglitazone.Proportional suppression of TNFαpromoter activity was observed when myocytes was transiently transfected with whole length of TNFαpromoter(-721/+17)after being stimulated with LPS and fenofibrate or pioglitazone,whereas no change of promoter activity was observed with transfection of TNFαreporter construct in deletion of NF-κB binding site(-182/+17).Conclusions PPARαand PPARγactivators may inhibit cardiac TNFαexpression but not accompanied by change of PPARαor PPARγmRNA expression.Therefore PPARαand PPARγactivators appear to play a role in anti-inflammation.The mechanism may partly be involved in suppression of the NF-κB pathway.展开更多
Objective Both decreased glomemlar filtration rate （GFR） and arterial stiffness were considered as risk factors for atherosclerosis. Previous studies have suggested the association between central arterial stiffness...Objective Both decreased glomemlar filtration rate （GFR） and arterial stiffness were considered as risk factors for atherosclerosis. Previous studies have suggested the association between central arterial stiffness and the degree of GFR loss. Whether decreased GFR contributes to peripheral artery stiffness remains controversial. Moreover, data analyzed from a cohort of Chinese women are rare. Our aim was to explore the relationship between GFR and regional arterial stiffness in Chinese women. Methods In this cross-sectional study, we randomly recruited 1131 adult women residents with GFR 〉 60 mL/min per 1.73 m2 estimated by the Chinese Modification of Diet in Renal Disease equation from three large communities. Central and peripheral arterial stiffness were estimated simultaneously by measuring carotid-femoral pulse wave velocity （PWVcf） and carotid-radial PWV （PWVcr） using a validated automatic device. Augmentation Index at heart rate 75 beats/minutes （AIx-75） was measured by pulse wave analysis as a composite parameter reflecting both large and distal arterial properties. Results The mean estimated GFR （eGFR） of the study group was 100.05 ＋ 23.26 mL/minute per 1.73 m2. Subjects were grouped by tertiles of eGFR level. PWVef and AIx-75 increased ongoing from the top to the bottom eGFR tertile, while the values of PWVcr were comparable. Both univariate Pearson correlations and multiple stepwise regression analyses showed that eGFR significantly correlated to PWVcf, but not to PWVcr and AJx-75. Conclusions In Chinese women with normal to mildly impaired renal function, decreased eGFR affected carotid-to-femoral rather than carotid-to-radial stiffening. This provides rational to conduct future prospective studies to investigate predictors of atherosclerosis in this population.展开更多
Tight junctions （TJs） are the most apical intercellular junctions of epithelial cells formed by occludin, claudins, junctional adhesion molecules （JAMs）, and zonula occludens （ZO）. Tight junction proteins can se...Tight junctions （TJs） are the most apical intercellular junctions of epithelial cells formed by occludin, claudins, junctional adhesion molecules （JAMs）, and zonula occludens （ZO）. Tight junction proteins can sense the presence of bacteria and regulate the transcription of target genes that encode effectors and regulators of the immune response. The aim of this study was to determine the impact of TJ proteins in response to Porphyromonas gingivalis （P. gingivalis）, P. gingivalis lipopolysaccharide （P. gingivalis LPS）, and extracellular adenosine triphosphate （ATP） in the oral epithelial cell culture model. Quantified real time- polymerase chain reaction （RT-PCR）, immunoblots, and immunostaining were performed to assess the gene and protein expression in TJs. It was found that P. gingivalis infection led to transient upregulation of the genes encoding occludin, claudin- 1, and claudin-4 but not JAM-A, claudin-15, or ZO-1, while P. gingivalis LPS increased claudin-1, claudin-15, and ZO-1 and decreased occludin, JAM-A, and claudin-4. Tight junction proteins showed significant upregulation in the above two groups when cells were pretreated with ATP for 3 h. The findings indicated that P. gingivalis induced the host defence responses at an early stage. P. gingivalis LPS exerted a more powerful stimulatory effect on the disruption of the epithelial barrier than P. gingivalis. ATP stimulation enhanced the reaction of TJ proteins to P. gingivalis invasion and LPS destruction of the epithelium.展开更多
Objective The National Natural Science Foundation of China(NSFC)has made great progress in promoting the development of aortic dissection research in recent years.This study aimed to examine the development and resear...Objective The National Natural Science Foundation of China(NSFC)has made great progress in promoting the development of aortic dissection research in recent years.This study aimed to examine the development and research status of aortic dissection research in China so as to provide references for future research.Methods The NSFC projects data from 2008 to 2019 were collected from the Internet-based Science Information System and other websites utilized as search engines.The publications and citations were retrieved by Google Scholar,and the impact factors were checked by the InCite Journal Citation Reports database.The investigator’s degree and department were identified from the institutional faculty profiles.Results A total of 250 grant funds totaling 124.3 million Yuan and resulting in 747 publications were analyzed.The funds in economically developed and densely populated areas were more than those in underdeveloped and sparsely populated areas.There was no significant difference in the amount of funding per grant between different departments’investigators.However,the funding output ratios of the grants for cardiologists were higher than those for basic science investigators.The amount of funding for clinical researchers and basic scientific researchers in aortic dissection was also similar.Clinical researchers were better in terms of the funding output ratio.Conclusion These results suggest that the medical and scientific research level of aortic dissection in China has been greatly improved.However,there are still some problems that urgently need to be solved,such as the unreasonable regional allocation of medical and scientific research resources,and the slow transition from basic science to clinical practice.展开更多
In the coevolutionary interactions between avian brood parasites and their hosts,egg recognition based on color and/or pattern is a common and effective defense to counter parasitism.However,for egg recognition based ...In the coevolutionary interactions between avian brood parasites and their hosts,egg recognition based on color and/or pattern is a common and effective defense to counter parasitism.However,for egg recognition based on size,only a few studies have found affirmative results,and they do not provide unambiguous evidence that egg size recognition in hosts has evolved as an important and specific anti-parasite adaptation against parasite eggs.We studied the brood parasite system between the Asian emerald cuckoo Chrysococcyx maculatus and its host,the chestnut-crowned warbler Phylloscopus castaniceps.The cuckoo parasitizes the warbler using non-mimetic and larger eggs at a parasitism rate of 12.9%.The warbler nests used in this experiment were built in a dark environment with the nest illuminance near 0 lux.Experiments with 2 types of model eggs with colors and patterns resembling cuckoo eggs of different sizes(cuckoo egg size or host egg size)showed that the warblers were able to reject 63.6%of cuckoo model eggs under these dim light conditions.However,model eggs with the same color and pattern similar to the warbler egg size were always accepted.This study provides strong evidence supporting the theory that egg size recognition can be evolved in hosts as a specific anti-parasite adaptation against cuckoos.We suggest that the egg size recognition of the warbler is an outcome of the tradeoff between the costs of violating the parental investment rule and suffering cuckoo parasitism.展开更多
Inspired by the phenomenon of superhydrophobic plants and animals in nature,1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)@copper stearate(CS)core-shell composites with similar properties was prepared.A rough shell layer...Inspired by the phenomenon of superhydrophobic plants and animals in nature,1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)@copper stearate(CS)core-shell composites with similar properties was prepared.A rough shell layer on the surface of the HMX was observed by scanning electron microscopy(SEM),and a series of in-depth characterization confirmed the successful generation of CS and the coreshell structure of the samples.Differential scanning calorimeter(DSC)proves that the crystal transition temperature(204℃)and high temperature decomposition exothermal temperature(284℃)of HMX@CS is almost unchanged compared with pure HMX,which means HMX and CS have good compatibility.Then,the H50 of the samples also increased continuously(16.6 cm→33.7 cm)when the CS shell content increased from 1%to 5%,indicating that the CS shell has a certain buffering performance,and CS will absorb some heat and melt under the stimulation of impact due to its low melting point,which improved impact sensitivity of HMX effectively further.Moreover,HMX@CS has excellent hydrophobic and oleophilic performance,shows excellent wettability with lipid binder,and samples with appropriate CS shell content can continue to combustion stably after covering water.This waterproof and low sensitivity coating provides a new way for the development of multifunctional energetic materials.展开更多
Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a commu- nity-based cohort. The gender differences in these associations were examined. Method...Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a commu- nity-based cohort. The gender differences in these associations were examined. Methods We evaluated the relationship between plasma homocysteine levels to three measures of vascular ftmction [carotid-femoral pulse wave velocity （CF-PWV）, carotid-ankle PWV （CA-PWV） and heart rate corrected augmentation index （AI）] in 1680 participants （mean age： 61.5 years; 709 men, 971 women） from communities of Beijing, China. Results In univariate analysis, plasma homocysteine levels was positively related to the CF-PWV （r = 0.211, P 〈 0.0001） and CA-PWV （r = 0.148, P 〈 0.0001）, whereas inversely associated with AI （r = -0.052, P = 0.016）. In multiple linear regression models adjusting for covariants, plasma homocysteine remained positively related to the CF-PWV （standardized 13 = 0.065, P = 0.007） in total cases. When the groups of men and women were examined separately, plasma homocysteine remained positively associated with the CF-PWV （standardized β = 0.082, P = 0.023） in men, whereas the relations between homocysteine and any of the arterial stiffness indices were not further present in women. Conclusions In Chinese population, plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women.展开更多
Porphyromonas gingivalis （P. gingivalis） has a strong association with the pathogenesis of periodontal disease. Recurrence of periodontal disease following therapy is attributed to numerous factors, and of growing i...Porphyromonas gingivalis （P. gingivalis） has a strong association with the pathogenesis of periodontal disease. Recurrence of periodontal disease following therapy is attributed to numerous factors, and of growing interest is the potential problem of intracellular bacteria that are able to persist and multiply within the host cell, thereby facilitating relapse of infection. The effect of antibiotic therapy in controlling P. gingivalis is questionable. Accordingly, while metronidazole is very effective against anaerobic extracellular P. gingivalis by disrupting the DNA of anaerobic microbial cells, this antibiotic does not effectively penetrate into mammalian cells to inhibit intracellular bacteria. Therefore in the present study, a modified porphyrin-linked metronidazole adducts, developed in our laboratory, was used to kill intracellular P. gingivalis. A series of experiments were performed, including cytotoxicity assays and cellular uptake of adducts by flow cytometry coupled with live cell imaging analysis, P. gingivalis invasion and elimination assays, and the analysis of colocalization of P. gingivalis and porphyrin-linked metronidazole by confocal laser scanning microscopy. Findings indicated that P. gingivalis and porphyrin-linked metronidazole were colocalized in the cytoplasm, and this compound was able to kill P. gingivalis intracellular with a sufficient culture time. This is a novel antimicrobial approach in the elimination of P. gingivalis from the oral cavity.展开更多
Studies on breeding biology enable us to broaden our understanding of the evolution of life history strategies.We studied the breeding biology of the Green-backed Tit(Parus monticolus)to provide comprehensive data on ...Studies on breeding biology enable us to broaden our understanding of the evolution of life history strategies.We studied the breeding biology of the Green-backed Tit(Parus monticolus)to provide comprehensive data on nest and egg characteristics,parental behavior throughout egg laying and nestling periods,and reproductive outcome.Our study reveals adaptive behavioral patterns and reproductive strategies for P.monticolus.展开更多
Objective: To study the significance of detecting au-toantibodies in primary hepatocarcinoma(PHC) pa-tients.Methods: Autoantibodies were detected by indirect im-munofluorescence assay. Antigens and antibodies ofHBV we...Objective: To study the significance of detecting au-toantibodies in primary hepatocarcinoma(PHC) pa-tients.Methods: Autoantibodies were detected by indirect im-munofluorescence assay. Antigens and antibodies ofHBV were determined by enzymeimmune assay. Antibodyto HCV IgG was detected by enzyme-linked immunoab-sorbent assay.Results: The positive rate of autoantibody was 27.3%(38/139) in 139 PHC patients. The main type of au-toantibodies in PHC was anti-nuclear antibody (36/38, 94.7%); others included anti-smooth muscle anti-body(2/38, 5.3% ), anti-mitochondria antibody(1/38, 2.6%), anti-midbody antibody (1/38, 2.6%), andanti-liver cell membrane antibody(2/38, 5.3%).Conclusions: Detecting autoantibodies in PHC patientsis of significance in studying the mechanism of au-toimmune reaction and etiology in PHC. The diversityof autoantibodies might result from a wide variety ofetiological factors involved in PHC development, andfrom a wide variety of overexpressed or mutated pro-teins involved in repeated cycles of necrosis and regen-eration in hepatocarcinoma development.展开更多
基金The authors are very grateful for the support received from the National Natural Science Foundation of China(No.11872121).
文摘The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered compound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.
基金supported by the National Natural Science Foundation of China(Grant No.11872121)。
文摘The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.
基金funded by the Education Department of Hainan Province(No.HnjgY,2022–12)the National Natural Science Foundation of China(No.32260127 to C.Y.)Doctoral Start-up Funds of China West Normal University(No.493002 to P.Y.).
文摘In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of parasite egg colors and markings in detection cues in hosts;however,studies focusing on the effects of egg size and quantity are relatively scarce and have mostly concentrated on the hosts of parasitic cowbirds.Here,we studied the egg recognition behaviors of a potential host of the Common Cuckoo(Cuculus canorus)—the Green-backed Tit(Parus monticolus),to determine:(1)whether the host uses the sizes of parasite eggs and/or the quantity contrast between parasite and host eggs as cues for recognition,(2)whether the host employs the template or discordant recognition mechanism for egg recognition,and(3)whether the size and quantity of parasite eggs affect the egg rejection modes of the hosts.The results indicate that Green-backed Tits did not use parasite egg size as a primary cue for egg recognition.We hypothesized that both visual and tactile detection might be involved in egg recognition by Green-backed Tits and suggest further studies after controlling for nest light conditions.Differences in egg quantity between parasites and hosts were not used as cues for egg recognition because the hosts employed the template mechanism rather than discordance to recognize parasite eggs.However,both the relative sizes and quantity of parasite and host eggs significantly affected the rejection modes of parasite eggs,and larger or more parasite eggs triggered higher probabilities of nest desertion in hosts.
基金grants from the Key National Basic Research Program of China，Nature Science Foundation of China (81270941) to Ye P,and the Nature Science Foundation of China，the Beijing Nova Program (Z121107002513124) to Bai Y
文摘Background Arterial stiffness and homocysteine are both powerful predictors of cardiovascular disease, especially in older popula tions. Previous studies have investigated the association of homocysteine with arterial stiffness in human subjects, while the relationship between homocysteine and arterial stiffness in the elderly is still indefinite. The current study examined the association of homocysteine with arterial stiffness in Chinese community-based elderly persons. Methods We related serum levels of homocysteine to two measures of arte- rial stiffness （carotid-femoral pulse wave velocity （PWV） and carotid-radial PWV） in 780 participants （46.3% men, mean age 71.9 years （ranging 65-96 years old）） from two communities of Beijing, China. Arterial stiffness were measured within two days of the time of bio- marker measurement. Results In multiple-adjusted models, homocysteine levels was strongly associated with the carotid-femoral PWV （standardized 13 = 0.13, P 〈 0.001）, even after adjustment for classical risk factors of cardiovascular disease. The association is also stronger when the carotid-femoral PWV is elevated above normal, whereas no significant association with homocysteine was observed for ca-rotid-radial PWV. Conclusions In Chinese elderly persons, serum homocysteine levels are associated with alterations of aortic stiffness.
基金funded by the Priority Academic Program Development of Jiangsu Higher Education Institution(Grant No.2014-37)the Jiangsu Provincial Health and Family Planning Commission(No.H201535)Orofacial Pain and TMD Research Unit,Institute of Stomatology,Affiliated Hospital of Stomatology,Nanjing Medical University,for their support
文摘Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.
基金Supported by The National Natural Science Foundation of China,No. 8127181012-5 state S and T Projects for infectious diseases,No. 2012ZX10002-007+1 种基金Doctoral Fund of Ministry of Education of China,No. 20120101110009the National Basic Research Program,No. 2013CB531405
文摘Hepatitis B virus(HBV)infection is a global public health problem that causes persistent liver diseases such as chronic hepatitis,cirrhosis,and hepatocellular carcinoma.A large amount of people die annually from HBV infection.However,the pathogenesises of the HBV-related diseases are ill defined and the therapeutic strategies for the diseases are less than optimum.The recently discovered microRNAs(miRNAs)are tiny noncoding RNAs that regulate gene expression primarily at the post-transcriptional level by binding to mRNAs.miRNAs contribute to a variety of physiological and pathological processes.A number of miRNAs have been found to play a pivotal role in the host-virus interaction including host-HBV interaction.Numerous studies have indicated that HBV infection could change the cellular miRNA expression patterns and different stages of HBV associated disease have displayed distinctive miRNA profiles.Furthermore,the differential expressed miRNAs have been found involved in the progression of HBV-related diseases,for instance some miRNAs are involved in liver tumorigenesis and tumor metastasis.Studies have also shown that the circulating miRNA in serum or plasma might be a very useful biomarker for the diagnosis and prognosis of HBV-related diseases.In addition,miRNA-based therapy strategies have attracted increasing attention,indicating a promising future in the treatment of HBV-related diseases.
基金Supported by the National Nature Science Foundation of China(30270551)Military"10.5"Foundation(02M012).
文摘Objective To investigate the effect of peroxisome proliferator-activated receptor-α(PPARα)and PPARγactivators on tumor necrosis factor-α(TNFα)expression in neonatal rat cardiac myocytes.Methods Primary cultures of cardiac myocytes from 1-to 3-day-old Wistar rats were prepared,and myocytes were ex-posed to lipopolysaccharide(LPS)and varying concentrations of PPARαor PPARγactivator(fenofibrate or pioglitazone).RT-PCR and ELISA were used to measure TNFα,PPARα,and PPARγexpression in cultured cardiac myocytes.Transient tr-ansfection of TNFαpromoter with or without nuclear factor-kappaB(NF-κB)binding site to cardiac myocytes was performed.Results Pretreatment of cardiac myocytes with fenofibrate or pioglitazone inhibited LPS-induced TNFαmRNA and protein expression in a dose-dependent manner.However,no significant changes were observed on PPARαor PPARγmRNA expression when cardiac myocytes were pretreated with fenofibrate or pioglitazone.Proportional suppression of TNFαpromoter activity was observed when myocytes was transiently transfected with whole length of TNFαpromoter(-721/+17)after being stimulated with LPS and fenofibrate or pioglitazone,whereas no change of promoter activity was observed with transfection of TNFαreporter construct in deletion of NF-κB binding site(-182/+17).Conclusions PPARαand PPARγactivators may inhibit cardiac TNFαexpression but not accompanied by change of PPARαor PPARγmRNA expression.Therefore PPARαand PPARγactivators appear to play a role in anti-inflammation.The mechanism may partly be involved in suppression of the NF-κB pathway.
文摘Objective Both decreased glomemlar filtration rate （GFR） and arterial stiffness were considered as risk factors for atherosclerosis. Previous studies have suggested the association between central arterial stiffness and the degree of GFR loss. Whether decreased GFR contributes to peripheral artery stiffness remains controversial. Moreover, data analyzed from a cohort of Chinese women are rare. Our aim was to explore the relationship between GFR and regional arterial stiffness in Chinese women. Methods In this cross-sectional study, we randomly recruited 1131 adult women residents with GFR 〉 60 mL/min per 1.73 m2 estimated by the Chinese Modification of Diet in Renal Disease equation from three large communities. Central and peripheral arterial stiffness were estimated simultaneously by measuring carotid-femoral pulse wave velocity （PWVcf） and carotid-radial PWV （PWVcr） using a validated automatic device. Augmentation Index at heart rate 75 beats/minutes （AIx-75） was measured by pulse wave analysis as a composite parameter reflecting both large and distal arterial properties. Results The mean estimated GFR （eGFR） of the study group was 100.05 ＋ 23.26 mL/minute per 1.73 m2. Subjects were grouped by tertiles of eGFR level. PWVef and AIx-75 increased ongoing from the top to the bottom eGFR tertile, while the values of PWVcr were comparable. Both univariate Pearson correlations and multiple stepwise regression analyses showed that eGFR significantly correlated to PWVcf, but not to PWVcr and AJx-75. Conclusions In Chinese women with normal to mildly impaired renal function, decreased eGFR affected carotid-to-femoral rather than carotid-to-radial stiffening. This provides rational to conduct future prospective studies to investigate predictors of atherosclerosis in this population.
文摘Tight junctions （TJs） are the most apical intercellular junctions of epithelial cells formed by occludin, claudins, junctional adhesion molecules （JAMs）, and zonula occludens （ZO）. Tight junction proteins can sense the presence of bacteria and regulate the transcription of target genes that encode effectors and regulators of the immune response. The aim of this study was to determine the impact of TJ proteins in response to Porphyromonas gingivalis （P. gingivalis）, P. gingivalis lipopolysaccharide （P. gingivalis LPS）, and extracellular adenosine triphosphate （ATP） in the oral epithelial cell culture model. Quantified real time- polymerase chain reaction （RT-PCR）, immunoblots, and immunostaining were performed to assess the gene and protein expression in TJs. It was found that P. gingivalis infection led to transient upregulation of the genes encoding occludin, claudin- 1, and claudin-4 but not JAM-A, claudin-15, or ZO-1, while P. gingivalis LPS increased claudin-1, claudin-15, and ZO-1 and decreased occludin, JAM-A, and claudin-4. Tight junction proteins showed significant upregulation in the above two groups when cells were pretreated with ATP for 3 h. The findings indicated that P. gingivalis induced the host defence responses at an early stage. P. gingivalis LPS exerted a more powerful stimulatory effect on the disruption of the epithelial barrier than P. gingivalis. ATP stimulation enhanced the reaction of TJ proteins to P. gingivalis invasion and LPS destruction of the epithelium.
基金supported by the National Natural Science Foundation of China(No.81800413 and No.81974048).
文摘Objective The National Natural Science Foundation of China(NSFC)has made great progress in promoting the development of aortic dissection research in recent years.This study aimed to examine the development and research status of aortic dissection research in China so as to provide references for future research.Methods The NSFC projects data from 2008 to 2019 were collected from the Internet-based Science Information System and other websites utilized as search engines.The publications and citations were retrieved by Google Scholar,and the impact factors were checked by the InCite Journal Citation Reports database.The investigator’s degree and department were identified from the institutional faculty profiles.Results A total of 250 grant funds totaling 124.3 million Yuan and resulting in 747 publications were analyzed.The funds in economically developed and densely populated areas were more than those in underdeveloped and sparsely populated areas.There was no significant difference in the amount of funding per grant between different departments’investigators.However,the funding output ratios of the grants for cardiologists were higher than those for basic science investigators.The amount of funding for clinical researchers and basic scientific researchers in aortic dissection was also similar.Clinical researchers were better in terms of the funding output ratio.Conclusion These results suggest that the medical and scientific research level of aortic dissection in China has been greatly improved.However,there are still some problems that urgently need to be solved,such as the unreasonable regional allocation of medical and scientific research resources,and the slow transition from basic science to clinical practice.
基金support has been provided by the Hainan Provincial Natural Science Foundation of China(320CXTD437 and 2019RC189)the Education Department of Hainan Province(HnjgY2022-12)+1 种基金C.Y.the National Natural Science Foundation of China(31672303 to C.Y.and 31970427 to W.L.).
文摘In the coevolutionary interactions between avian brood parasites and their hosts,egg recognition based on color and/or pattern is a common and effective defense to counter parasitism.However,for egg recognition based on size,only a few studies have found affirmative results,and they do not provide unambiguous evidence that egg size recognition in hosts has evolved as an important and specific anti-parasite adaptation against parasite eggs.We studied the brood parasite system between the Asian emerald cuckoo Chrysococcyx maculatus and its host,the chestnut-crowned warbler Phylloscopus castaniceps.The cuckoo parasitizes the warbler using non-mimetic and larger eggs at a parasitism rate of 12.9%.The warbler nests used in this experiment were built in a dark environment with the nest illuminance near 0 lux.Experiments with 2 types of model eggs with colors and patterns resembling cuckoo eggs of different sizes(cuckoo egg size or host egg size)showed that the warblers were able to reject 63.6%of cuckoo model eggs under these dim light conditions.However,model eggs with the same color and pattern similar to the warbler egg size were always accepted.This study provides strong evidence supporting the theory that egg size recognition can be evolved in hosts as a specific anti-parasite adaptation against cuckoos.We suggest that the egg size recognition of the warbler is an outcome of the tradeoff between the costs of violating the parental investment rule and suffering cuckoo parasitism.
基金financially supported by the National Natural Science Foundation of China (Grant NO.11702268)Sichuan provincial key S&T Special Projects (Grant NO.19DZX0106)
文摘Inspired by the phenomenon of superhydrophobic plants and animals in nature,1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)@copper stearate(CS)core-shell composites with similar properties was prepared.A rough shell layer on the surface of the HMX was observed by scanning electron microscopy(SEM),and a series of in-depth characterization confirmed the successful generation of CS and the coreshell structure of the samples.Differential scanning calorimeter(DSC)proves that the crystal transition temperature(204℃)and high temperature decomposition exothermal temperature(284℃)of HMX@CS is almost unchanged compared with pure HMX,which means HMX and CS have good compatibility.Then,the H50 of the samples also increased continuously(16.6 cm→33.7 cm)when the CS shell content increased from 1%to 5%,indicating that the CS shell has a certain buffering performance,and CS will absorb some heat and melt under the stimulation of impact due to its low melting point,which improved impact sensitivity of HMX effectively further.Moreover,HMX@CS has excellent hydrophobic and oleophilic performance,shows excellent wettability with lipid binder,and samples with appropriate CS shell content can continue to combustion stably after covering water.This waterproof and low sensitivity coating provides a new way for the development of multifunctional energetic materials.
基金This work was supported by grants from the Key National Basic Research Program of China （2012CB517503, 2013CB530804） and Nature Science Foundation of China （81270941） to Ye P, and the Nature Science Foundation of China （81100878） and the Beijing Nova Program （Z121107002513124） to Bai Y. The authors have no conflict of interest to declare.
文摘Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a commu- nity-based cohort. The gender differences in these associations were examined. Methods We evaluated the relationship between plasma homocysteine levels to three measures of vascular ftmction [carotid-femoral pulse wave velocity （CF-PWV）, carotid-ankle PWV （CA-PWV） and heart rate corrected augmentation index （AI）] in 1680 participants （mean age： 61.5 years; 709 men, 971 women） from communities of Beijing, China. Results In univariate analysis, plasma homocysteine levels was positively related to the CF-PWV （r = 0.211, P 〈 0.0001） and CA-PWV （r = 0.148, P 〈 0.0001）, whereas inversely associated with AI （r = -0.052, P = 0.016）. In multiple linear regression models adjusting for covariants, plasma homocysteine remained positively related to the CF-PWV （standardized 13 = 0.065, P = 0.007） in total cases. When the groups of men and women were examined separately, plasma homocysteine remained positively associated with the CF-PWV （standardized β = 0.082, P = 0.023） in men, whereas the relations between homocysteine and any of the arterial stiffness indices were not further present in women. Conclusions In Chinese population, plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women.
基金supported by the Postgraduate Research Program from The University of Sydney
文摘Porphyromonas gingivalis （P. gingivalis） has a strong association with the pathogenesis of periodontal disease. Recurrence of periodontal disease following therapy is attributed to numerous factors, and of growing interest is the potential problem of intracellular bacteria that are able to persist and multiply within the host cell, thereby facilitating relapse of infection. The effect of antibiotic therapy in controlling P. gingivalis is questionable. Accordingly, while metronidazole is very effective against anaerobic extracellular P. gingivalis by disrupting the DNA of anaerobic microbial cells, this antibiotic does not effectively penetrate into mammalian cells to inhibit intracellular bacteria. Therefore in the present study, a modified porphyrin-linked metronidazole adducts, developed in our laboratory, was used to kill intracellular P. gingivalis. A series of experiments were performed, including cytotoxicity assays and cellular uptake of adducts by flow cytometry coupled with live cell imaging analysis, P. gingivalis invasion and elimination assays, and the analysis of colocalization of P. gingivalis and porphyrin-linked metronidazole by confocal laser scanning microscopy. Findings indicated that P. gingivalis and porphyrin-linked metronidazole were colocalized in the cytoplasm, and this compound was able to kill P. gingivalis intracellular with a sufficient culture time. This is a novel antimicrobial approach in the elimination of P. gingivalis from the oral cavity.
基金provided by Hainan Provincial Natural Science Foundation of China(320CXTD437 and 2019RC189 to CY)National Natural Science Foundation of China(31672303 to CY)Hainan Provincial Innovative Research Program for Graduates(Hyb2020-48 to PY)。
文摘Studies on breeding biology enable us to broaden our understanding of the evolution of life history strategies.We studied the breeding biology of the Green-backed Tit(Parus monticolus)to provide comprehensive data on nest and egg characteristics,parental behavior throughout egg laying and nestling periods,and reproductive outcome.Our study reveals adaptive behavioral patterns and reproductive strategies for P.monticolus.
文摘Objective: To study the significance of detecting au-toantibodies in primary hepatocarcinoma(PHC) pa-tients.Methods: Autoantibodies were detected by indirect im-munofluorescence assay. Antigens and antibodies ofHBV were determined by enzymeimmune assay. Antibodyto HCV IgG was detected by enzyme-linked immunoab-sorbent assay.Results: The positive rate of autoantibody was 27.3%(38/139) in 139 PHC patients. The main type of au-toantibodies in PHC was anti-nuclear antibody (36/38, 94.7%); others included anti-smooth muscle anti-body(2/38, 5.3% ), anti-mitochondria antibody(1/38, 2.6%), anti-midbody antibody (1/38, 2.6%), andanti-liver cell membrane antibody(2/38, 5.3%).Conclusions: Detecting autoantibodies in PHC patientsis of significance in studying the mechanism of au-toimmune reaction and etiology in PHC. The diversityof autoantibodies might result from a wide variety ofetiological factors involved in PHC development, andfrom a wide variety of overexpressed or mutated pro-teins involved in repeated cycles of necrosis and regen-eration in hepatocarcinoma development.
