Background The effectiveness of life skills-based prevention programs to prevent substance addiction has been underexplored in Türkiye,likely in part due to the lack of validated measurement tools developed speci...Background The effectiveness of life skills-based prevention programs to prevent substance addiction has been underexplored in Türkiye,likely in part due to the lack of validated measurement tools developed specifically for that purpose.Therefore,the aim of this study is to develop a tool to measure life skills for middle school students.The present study aims to test the factorial structure,reliability,convergent and discriminant validity,and measurement invariance across gender and age groups of the Green Crescent Life Skills(GCLS)Scale.Methods The study was conducted in Istanbul with two different sample groups.The first sample consisted of 566 and the second sample consisted of 885 middle school students.In the study,exploratory factor analysis(EFA)was applied to the first sample,and confirmatory factor analysis(CFA)was applied to the second sample to test the factorial structure of the scale.Convergent and discriminant validity were examined to provide evidence for construct-based validity.The reliability of the scale was assessed with Cronbach’sα,composite reliability,McDonald’sω,and test-retest.Results The EFA results showed that the scale consisted of four factors(self-awareness,coping with negative emotions,thinking skills,and peer relations).CFA results also confirmed this structure.The results revealed a significant positive correlation(r=0.52,p<0.01)between life skills and avoidance self-efficacy scores,as well as a significant negative correlation(r=−0.53,p<0.01)between life skills and attitude toward drug use scores.Additionally,it was found that measurement invariances based on gender and age groups were provided.It was determined that all sub-dimensions had sufficient reliability levels.Conclusion The findings of this validation study show that the GCLS Scale,which assesses four skills in a self-reported format,is a valid and reliable scale with considerable potential utility in monitoring life skills in Turkish adolescent populations.展开更多
The Crescent Moon Spring is a precious natural heritage. However, the dynamic characteristics of megadunes around the Crescent Moon Spring are not well known. This paper quantitatively studied the character- istics an...The Crescent Moon Spring is a precious natural heritage. However, the dynamic characteristics of megadunes around the Crescent Moon Spring are not well known. This paper quantitatively studied the character- istics and changes of megadunes around the Crescent Moon Spring by interpreting aerial photographs taken in 1985 and 2004 and analysing the dune crestlines and the wind data collected from 2011 to 2012. Results revealed that pyramid dunes were formed by a complex wind regime. The Crescent Moon Spring was not buried by shifting sands because of the stable wind regime and relative stability of pyramid dunes. The crestlines of the dunes around the spring moved northward between 1985 and 2004. The south-facing slip faces were also exposed to wind ero- sion, whereas the other faces were under deposition, thus indicating that the southerly wind was relatively en- hanced. Limiting the scale of tall windbreaks and architectures in the Dunhuang oasis at the north of the spring was necessary to maintain the dynamic equilibrium of the wind regime and sand transport.展开更多
Aerial photographs and 3-D laser scans of a 90-m high star dune at the Crescent Moon Spring scenic spot in Dunhuang,China,are used to investigate the changes in dune morphology on timescales from months to decades.The...Aerial photographs and 3-D laser scans of a 90-m high star dune at the Crescent Moon Spring scenic spot in Dunhuang,China,are used to investigate the changes in dune morphology on timescales from months to decades.The result revealed that relative-equilibrium airflow strength in three wind directions of northeast,west and south was an important condition for the stability of star dunes with limited migration.Transverse and longitudinal airflows exerted a crucial impact on variation processes of star dune morphology.Controlled by transverse airflows,the easterly winds,the east side was dominated by wind erosion;and strong deposition occurred on the south-south-east arm with a maximum deposition rate of 0.44 m/a in the 46-a monitoring period,causing the east side becoming steep and high.Controlled by longitudinal airflows,the westerly winds,the west-north-west side was mainly eroded and the north arm migrated from west to east with a rate of 0.30 m/a,causing the dune slope becoming gentle and elongate.The local air circulation(southerly winds)exerted a significant impact on the development process of the star dune.Due to the influence of human activities,the south side present surface processes from a concave profile to a convex profile in 46 a,which is a potential threat to the Crescent Moon Spring.The results indicate that rehabilitating the airflow field at most is a crucial strategy to the protection of Crescent Moon Spring from burial.Opening up the passage of easterly,westerly and southerly winds through intermediately cutting the protection forest,demolishing the enclosed wall and changing the pavilion into a porous pattern have been suggested to protect the Crescent Moon Spring from burial.展开更多
Although scientists have performed many studies on crescent （barchan） dunes in the Taklimakan Desert,few studies reported the changes in grain size at different development stages of crescent dunes.In order to evalu...Although scientists have performed many studies on crescent （barchan） dunes in the Taklimakan Desert,few studies reported the changes in grain size at different development stages of crescent dunes.In order to evaluate the changing trends of surface sediment grain size with dune development,we investigated the grain size characteristics at four developmental stages （oval sand pile,shield dune,incipient crescent dune and mature crescent dune） of crescent dunes by measuring the morphology of sand dune and observing the near-surface wind regime.The dunes have developed in a wide inter-dune corridor between high compound longitudinal ridges in China＇s Taklimakan Desert.The surface sediments at four developmental stages of the crescent dunes were primarily composed of fine sands,followed by very fine and medium sands.Mean grain sizes ranged from 2.8 to 3.1 φ,with a unimodal distribution.The sands were moderately well-sorted,their distribution varied from platykurtic to very platykurtic,and symmetrical or skewed towards the fine particles.From oval sand piles through shield and incipient crescent dunes to mature crescent dunes,incipient grain size gradually increased,particles became finer,sorting became better,kurtosis and skewness increased.Grain sizes on the surface layer became coarser upwards from the toe of the windward slope and then became finer towards the bottom of the leeward slope.We found that the coarsest particles at different positions at the four developmental stages were different.The coarsest particles were distributed at the top of the oval sand piles and shield dunes,versus at the middle of the windward slope of the incipient and mature crescent dunes.Correlations between the mean grain size and other grain size parameters showed that as mean grain size became finer,sorting became better and kurtosis became wider,but skewness changed only slightly.In addition,grain size variation in the surface sediments correlated with the movement speed of the dunes in the study area.In the open ground among tall-complex longitudinal ridges in the hinterland of the Taklimakan Desert where aeolian environment is characterized by comparatively strong wind and unsaturated sand flow,faster dune movement corresponded to coarser grain size.展开更多
A series of experiments on the instability of steeP water wave trains in water with finite water depths and infinite water depths in a wide wave basin were performed. It was found that under the coupled development of...A series of experiments on the instability of steeP water wave trains in water with finite water depths and infinite water depths in a wide wave basin were performed. It was found that under the coupled development of modulational instability and class-Ⅱ instability, the initial two-dimensional steep wave trains evolved into three＇dimensional crescent waves, followed by the occurrence of disordered water surfaces, and that the wave energy transferred to sidebands in the amplitude spectrum of the water surface elevation. The results also show that water depth has a significant effect on the growth of modulational instability and the evolutiin of crescent waves. The larger the water depth, the more quickly the modulational instability suppresses class-II instability.展开更多
Desert lake, a unique oasis in desert ecosystems, harbours different bacterial communities. Thus, it is considered as a hub of bacterial diversity. In this study, bacterial diversity in the sediment of Crescent Moon S...Desert lake, a unique oasis in desert ecosystems, harbours different bacterial communities. Thus, it is considered as a hub of bacterial diversity. In this study, bacterial diversity in the sediment of Crescent Moon Spring, Kumtag Desert, Northwest China was analyzed using high-throughput amplicon pyrosequencing analysis. The sequences of the most abundant OUTs （Operational Taxonomic Units） in the sediment of Crescent Moon Spring were compared with the sequences of those most abundant OUTs of various origins from NCBI GenBank database to detect the origins of bacteria in the sediment of Crescent Moon Spring. Also, bacterial compositions between sediment of Crescent Moon Spring and other desert and lake ecosystems （including desert lakes） worldwide were compared using cluster analysis to determine the possible factors affecting bacterial compositions. In total, 11,855 sequences were obtained and 30 phyla were identified. At the phylum level, the dominant phylum was Proteobacteria with α-Proteobacteria being the first dominant class and the second dominant phylum was Planctomycetes. Our finding that α-Proteobacteria being the first dominant class of Proteobacteria and Planctomycetes being the second dominant phyla are somewhat contradictory with reports from other desert lake sediments. This difference could be resulted from water hydration and conductivity, as well as oligotrophic conditions of Crescent Moon Spring. At the genus level, Rhodobacter, Caldilinea, Planctomyces, and Porphyrobacterwere the dominant genera in the sediment of Crescent Moon Spring. Comparisons on sequences of the most abundant OUTs （including OTU3615, OTU6535, and OTU6646） between sediment of Crescent Moon Spring and various origins from NCBI GenBank database indicate that the origins of bacteria in the sediment of Crescent Moon Spring are likely from the underground water. Furthermore, cluster analysis on comparisons of bacteria compositions between sediment of Crescent Moon Spring and other desert and lake ecosystems （including desert lakes） worldwide shows that at regional scales, bacterial compositions may be mainly affected by geographical patterns, precipitation amounts, and pH values. Collectively, our results provide new knowledge on the bacterial diversity in desert lake ecosystems.展开更多
Antineutrophil cytoplasmic antibodies(ANCA) are well known to be associated with several types of vasculitis, including pauci-immune crescentic glomerulonephritis, a form of rapid progressive glomerular nephritis(RPGN...Antineutrophil cytoplasmic antibodies(ANCA) are well known to be associated with several types of vasculitis, including pauci-immune crescentic glomerulonephritis, a form of rapid progressive glomerular nephritis(RPGN). ANCA vasculitis has also been reported after administration of propylthiouracil, hydralazine, cocaine(adulterated with levimasole), allopurinol, penicillamine and few other drugs. All previously reported cases of drug-associated ANCA glomerulonephritis were in native kidneys. Sofosbuvir is a new and effective drug for hepatitis C virus infection. Here, we report a case of ANCA vasculitis and RPGN following sofosbuvir administration in a kidney transplant recipient. It also represents the first case of drug-associated ANCA vasculitis in a transplanted kidney. Further drug monitoring is necessary to elucidate the degree of association and possible causal effect of sofosbuvir and perinuclear ANCA vasculitis.展开更多
The Singing Sand Mountain and Crescent Spring Scenic Spot in Dunhuang,Northwest China is a world-renowned desert attraction that is also an integral component of the Dunhuang UNESCO Global Geopark.This scenic area und...The Singing Sand Mountain and Crescent Spring Scenic Spot in Dunhuang,Northwest China is a world-renowned desert attraction that is also an integral component of the Dunhuang UNESCO Global Geopark.This scenic area underwent a 30-year transformation,i.e.,from a severe sand risk with spring water threatened by sand burial due to dune deformation,to restoration of the original sand flow field and mitigation of the sand burial problem.The current paper summarizes the research on the intensive monitoring of the dynamic change of star dunes near the spring,observation of wind and sand flow movement,and then restoring the harmonic vibration of the sand particles(singing sand)that were previously silenced.The existing and prospective impacts of anthropogenic and natural forces on the deformation of the sand dunes are investigated by integrated methods,guiding the implementation of mitigating measures with significant ameliorative effects.Contrast to common sand control practices that aim to reduce wind speed and stop blown sands,our research highlights the importance of maintaining the natural wind flow field in stabilizing surrounding dunes.These mitigation measures consist of removing excessive vegetation and newly constructed buildings to recover the original wind flow field and sand transport activity.Such research and mitigation efforts ensure the scientific protection and restoration of the special desert landform,and contribute to the mutual enhancement of the conservation and exploitation of this desert scenic spot and similar sites.展开更多
AIM To study the usefulness of orbital ultrasonography in the diagnosis of papilledema.METHODS Fifty patients who were referred to the neurophthalmology clinic and clinically suspected to have papilledema were selecte...AIM To study the usefulness of orbital ultrasonography in the diagnosis of papilledema.METHODS Fifty patients who were referred to the neurophthalmology clinic and clinically suspected to have papilledema were selected. Thorough, clinical examination with slitlamp biomicroscopy and visual acuity assessment was done. These patients underwent ultrasonography to demonstrate the crescent sign. The patients were further evaluated with the neurologist and magnetic resonance imaging(MRI) thus confirming the diagnosis of papilledema. The results of our ultrasonographic evaluation were correlated with final diagnosis after thorough clinical evaluation, imaging and the neurologist's opinion.RESULTS Out of 50 patients diagnosed having papilledema on MRI, 46(92%) showed crescent sign on B scan ultrasonography. Headache was most common presenting complaint in 47(94%) and idiopathic intracranial hypertension was most common underlying cause of papilledema in 30(60%) cases.CONCLUSION"Crescent sign" seen on ultrasonography is a sensitive tool for diagnosis of papilledema. It is cost effective, less cumbersome and effective tool to differentiatebetween papilledema and pseudo papilledema before subjecting the patients to costly investigations like MRI. A positive crescent sign should always be followed by MRI to find out the cause of papilledema.展开更多
This paper studies the evolution of crescent-shaped dune under the influence of injected flux. A scaling law and a wind tunnel experiment are carried out for comparison. The experiment incorporates a novel image proce...This paper studies the evolution of crescent-shaped dune under the influence of injected flux. A scaling law and a wind tunnel experiment are carried out for comparison. The experiment incorporates a novel image processing algorithm to recover the evolutionary process. The theoretical and experimental results agree well in the middle stage of dune evolution, but deviate from each other in the initial and final stages, suggesting that the crescent-shaped dune evolution is intrinsically scale-variant and that the crescent shape breaks down under unsaturated condition.展开更多
The Arab Spring is supposed to be the Arab world’s great changes and turmoil,but Iran has repeatedly become the focus in the following changes.Whether it is in the Syrian civil war,or strikes against ISIS,or the Qata...The Arab Spring is supposed to be the Arab world’s great changes and turmoil,but Iran has repeatedly become the focus in the following changes.Whether it is in the Syrian civil war,or strikes against ISIS,or the Qatar crisis,Iran repeatedly appeared.There are different attitudes towards Iran’s behavior.The Trump administration holds the opinion that Iran is展开更多
Here two cases of renal failure occurring in pregnancy were reported,with biopsy-proven pauci-immune crescentic glomerulonephritis at postpartum.It is most rare that pauci-immune crescentic glomerulonephritis as the c...Here two cases of renal failure occurring in pregnancy were reported,with biopsy-proven pauci-immune crescentic glomerulonephritis at postpartum.It is most rare that pauci-immune crescentic glomerulonephritis as the cause of renal failure in pregnancy.Their renal function could remain stable for some time due to timely and appropriate treatment.Therefore,the pregnant and maternal who have the performance of renal impairment should be closely tracked their blood pressure,urinary protein and renal function,if necessary,execute renal biopsy,for a clear and accurate pathological diagnosis is of great significance to grasp the opportunity of treatment.But the long-term prognosis is still poor.展开更多
Objective To study the significance and distribution of renal infiltrating cells, including monocytes (CD68+ cells), proliferative cell nuclear antigen positive cells (PCNA+ cells), CD4+ and CD8+ cells in diffuse cres...Objective To study the significance and distribution of renal infiltrating cells, including monocytes (CD68+ cells), proliferative cell nuclear antigen positive cells (PCNA+ cells), CD4+ and CD8+ cells in diffuse crescent glomerulonephritis (DCGN). Methods Fifty-six patients with DCGN were studied, including 10 cases of anti-glomerular basement membrane (GBM)-type Ⅰ DCGN, 26 immune complex-type Ⅱ DCGN, and 20 cases of pauci-immune-type Ⅲ DCGN. Glomerular and interstitial infiltrates of CD68+ and PCNA+ cells, and interstitial infiltrates of CD4+ and CD8+ cells were detected by using four-layer PAP methods. Results There was a significant increase of renal infiltrating CD68+, PCNA+, CD4+ and CD8+ cells in patients with DCGN compared with that in normal controls. In patients with type Ⅰ DCGN, there was a higher number of renal infiltrating CD68+ and PCNA+ cells than that in patients with type Ⅱ and Ⅲ DCGN. A glomerular infiltrates of CD68+ and PCNA+ cells correlated with the interstitial infiltrates of CD4+ cells in type Ⅰ or Ⅲ DCGN patients. In lupus DCGN patients, the numbers of renal infiltrating CD68+ and PCNA+ cells were similar to vasculitis or type Ⅲ DCGN patients.Conclusion These findings demonstrate that the renal infiltrates of CD68+ and PCNA+ cells play an important role in patients with DCGN, that the infiltrates of CD4+ cells correlate with the infiltrates of CD68+ and PCNA+ cells may be an active marker of DCGN, and that cell-mediated immunity may contribute to crescent formation in lupus DCGN patients.展开更多
Background MicroRNA-29b(miR-29b)has been suggested to possess pro-inflammatory activity,which can partially be explained by the repression of tumor necrosis factor alpha protein three antibody(TNFAIP3).Meanwhile,it al...Background MicroRNA-29b(miR-29b)has been suggested to possess pro-inflammatory activity,which can partially be explained by the repression of tumor necrosis factor alpha protein three antibody(TNFAIP3).Meanwhile,it also promotes thyroid cell proliferation via Smad signaling pathways.The present study aimed to elucidate the role of miR-29b in Henoch Sch(o)nlein purpura nephritis(HSPN)and its underlying molecular mechanism in angiotensinⅡ(AngⅡ)-induced human glomerular mesangial cell(HGMC)activation.Methods We evaluated miR-29b expression in 35 HSPN renal tissues based on crescent formation,glomerular sclerosis,interstitial fibrosis,thrombosis formation and capillary loop necrosis.Meanwhile,HGMCs were cultured,treated with AngⅡand then transfected with LV-hsa-miR-29b-1 to induce miR-29b overexpression or LV-hsa-miR-29b-3p-inhibition to inhibit miR-29b expression.Finally,we examined the effects of miR-29b on cell proliferation and release of inflammatory mediators.Results We observed that miR-29b expression was significantly higher in the crescent group than in the no crescent group.MiR-29b overexpression induced the release of intercellular adhesion molecule-1,interleukin-1β(IL-1β),IL-6,IL-8,the increase of CyclinA2,CyclinD 1,and cell proliferation.It also could inhibit the expressions of TNFAIP3 and NF-kappa-B-repressing factor(NKRF).Correspondingly,miR-29b inhibition produced the opposite effects and increased the expression of TNFAIP3 and NKRF.Conclusion MiR-29b expression is altered in crescent formation of HSPN and accelerates AngⅡ-induced mesangial cell proliferation and release of inflammatory mediators.展开更多
Infective endocarditis （IE） is associated with poor prognosis and higher mortality. IE-induced glomerulonephritis, especially crescentic glomerulonephritis （IE-CGN） with renal dysfunction, is an independent risk f...Infective endocarditis （IE） is associated with poor prognosis and higher mortality. IE-induced glomerulonephritis, especially crescentic glomerulonephritis （IE-CGN） with renal dysfunction, is an independent risk factor for mortality For the treatment of IE-CGN, many therapeutic strategies including antibiotics alone, antibiotics combined with corticosteroid, immunosuppressive agents, plasmapheresis, or cardiac surgery have been applied and obtained various results.C21 Here, we reported a case of CGN with progressive renal failure secondary to IE in which the renal function was dramatically improved by the treatment of surgical valve replacement and antibiotics.展开更多
Objective To investigate retrospectively the incidence, distribution of primary disease and clinicopathologic characteristics of diffuse crescentic glomerulonephritis (DCGN) in Chinese patients.Methods One hundred and...Objective To investigate retrospectively the incidence, distribution of primary disease and clinicopathologic characteristics of diffuse crescentic glomerulonephritis (DCGN) in Chinese patients.Methods One hundred and seventy-two consecutive patients diagnosed as having DCGN out of 9828 cases of non-transplanting renal biopsies over sixteen years, were studied. DCGN is categorized into three types according to immunopathologic characteristics. The incidence of this disease, its primary diseases, clinical characteristics and serum antineutrophil cytoplasmic antibodies (ANCAs) were analyzed.Results The distribution of patients among the three classifications was 8. 7% type Ⅰ , 68. 6% type Ⅱ and 22. 7% type Ⅲ. Clinically, the majority of patients (69.8%) presented rapidly progressive glomerulonephritis (RPGN), but 30. 2% manifested a chronic nephritic syndrome or chronic renal failure. In terms of related conditions, 93% were anemic, 61. 6% had hypertension, 50. 6% oliguria, 45.3% nephrotic syndrome, 43% uremic syndrome and 39.5% displayed gross hematuria. Those patients who were positive in serum for ANCAs had predominantly type Ⅲ DCGN. Two cases with anti-GBM-antibody crescentic glomerulonephritis and three with lupus nephritis were also positive for ANCAs in serum.Conclusion DCGN is not rare in Chinese patients. A majority of patients in our study presented with RPGN, but 30. 2% manifested a chronic renal failure. Lupus patients with DCGN that were positive for ANCAs had more severe vasculitic lesions.展开更多
Objective To evaluate the significance of serum anti neutrophil cytoplasmic antibodies (ANCAs) and the effects of immune suppressive treatments on its activity in patients with pauci immune crescentic glomeruloneph...Objective To evaluate the significance of serum anti neutrophil cytoplasmic antibodies (ANCAs) and the effects of immune suppressive treatments on its activity in patients with pauci immune crescentic glomerulonephritis (PICGN) Methods Serum ANCAs and myeloperoxidase (MPO) ANCA were detected by indirect immunofluorescence and enzyme linked immuno^sorbent assay (ELISA) methods respectively, and the renal tissues infiltrating cells including CD4 +, CD8 +, CD68 + and PCNA + cells were determined by four layer peroxidase antiperoxidase (PAP) method The clinical manifestations, pathologic features and immune pathologic changes in patients with positive ANCAs were compared with that in patients with negative ANCAs The effects of immune suppressive therapy on clinic and pathologic changes as well as ANCAs activity were also investigated in ANCAs positive and ANCAs negative patients Results Both of clinic active manifestations such as the degree of hematuria, rapidly progressive renal failure and pathologic active features including segmental capillary necrosis and vasculitis were much common in patients with positive ANCAs as compared with that in patients with negative ANCAs The number of infiltrating cells in renal tissue, especially CD4 + cells, was markedly higher in ANCAs positive patients than that in ANCAs negative patients The effects of immune suppressive therapy were also much better in patients with positive ANCAs than that in patients with negative ANCAs Conclusion Serum ANCAs is not only a marker for diagnosis of systemic vasculitis, but also a sensitive predictor for evaluation of diseases' activity and treatment in patients with PICGN The good effect of immune suppressive treatments on patients with PICGN is partially associated with the degree of ANCAs activity展开更多
基金supported by the Turkish Green Crescent Society under Grant[41402653-160-6/333].
文摘Background The effectiveness of life skills-based prevention programs to prevent substance addiction has been underexplored in Türkiye,likely in part due to the lack of validated measurement tools developed specifically for that purpose.Therefore,the aim of this study is to develop a tool to measure life skills for middle school students.The present study aims to test the factorial structure,reliability,convergent and discriminant validity,and measurement invariance across gender and age groups of the Green Crescent Life Skills(GCLS)Scale.Methods The study was conducted in Istanbul with two different sample groups.The first sample consisted of 566 and the second sample consisted of 885 middle school students.In the study,exploratory factor analysis(EFA)was applied to the first sample,and confirmatory factor analysis(CFA)was applied to the second sample to test the factorial structure of the scale.Convergent and discriminant validity were examined to provide evidence for construct-based validity.The reliability of the scale was assessed with Cronbach’sα,composite reliability,McDonald’sω,and test-retest.Results The EFA results showed that the scale consisted of four factors(self-awareness,coping with negative emotions,thinking skills,and peer relations).CFA results also confirmed this structure.The results revealed a significant positive correlation(r=0.52,p<0.01)between life skills and avoidance self-efficacy scores,as well as a significant negative correlation(r=−0.53,p<0.01)between life skills and attitude toward drug use scores.Additionally,it was found that measurement invariances based on gender and age groups were provided.It was determined that all sub-dimensions had sufficient reliability levels.Conclusion The findings of this validation study show that the GCLS Scale,which assesses four skills in a self-reported format,is a valid and reliable scale with considerable potential utility in monitoring life skills in Turkish adolescent populations.
基金funded by the National Key Technology R&D Program of China (2013BAC07B02)the National Natural Science Foundation of China (41071009)the West Light Foundation of Chinese Academy of Sciences (29Y128841)
文摘The Crescent Moon Spring is a precious natural heritage. However, the dynamic characteristics of megadunes around the Crescent Moon Spring are not well known. This paper quantitatively studied the character- istics and changes of megadunes around the Crescent Moon Spring by interpreting aerial photographs taken in 1985 and 2004 and analysing the dune crestlines and the wind data collected from 2011 to 2012. Results revealed that pyramid dunes were formed by a complex wind regime. The Crescent Moon Spring was not buried by shifting sands because of the stable wind regime and relative stability of pyramid dunes. The crestlines of the dunes around the spring moved northward between 1985 and 2004. The south-facing slip faces were also exposed to wind ero- sion, whereas the other faces were under deposition, thus indicating that the southerly wind was relatively en- hanced. Limiting the scale of tall windbreaks and architectures in the Dunhuang oasis at the north of the spring was necessary to maintain the dynamic equilibrium of the wind regime and sand transport.
基金funded by the National Natural Science Foundation of China(41271023)
文摘Aerial photographs and 3-D laser scans of a 90-m high star dune at the Crescent Moon Spring scenic spot in Dunhuang,China,are used to investigate the changes in dune morphology on timescales from months to decades.The result revealed that relative-equilibrium airflow strength in three wind directions of northeast,west and south was an important condition for the stability of star dunes with limited migration.Transverse and longitudinal airflows exerted a crucial impact on variation processes of star dune morphology.Controlled by transverse airflows,the easterly winds,the east side was dominated by wind erosion;and strong deposition occurred on the south-south-east arm with a maximum deposition rate of 0.44 m/a in the 46-a monitoring period,causing the east side becoming steep and high.Controlled by longitudinal airflows,the westerly winds,the west-north-west side was mainly eroded and the north arm migrated from west to east with a rate of 0.30 m/a,causing the dune slope becoming gentle and elongate.The local air circulation(southerly winds)exerted a significant impact on the development process of the star dune.Due to the influence of human activities,the south side present surface processes from a concave profile to a convex profile in 46 a,which is a potential threat to the Crescent Moon Spring.The results indicate that rehabilitating the airflow field at most is a crucial strategy to the protection of Crescent Moon Spring from burial.Opening up the passage of easterly,westerly and southerly winds through intermediately cutting the protection forest,demolishing the enclosed wall and changing the pavilion into a porous pattern have been suggested to protect the Crescent Moon Spring from burial.
基金supported by the National Natural Science Foundation of China (41571011,41330746)
文摘Although scientists have performed many studies on crescent （barchan） dunes in the Taklimakan Desert,few studies reported the changes in grain size at different development stages of crescent dunes.In order to evaluate the changing trends of surface sediment grain size with dune development,we investigated the grain size characteristics at four developmental stages （oval sand pile,shield dune,incipient crescent dune and mature crescent dune） of crescent dunes by measuring the morphology of sand dune and observing the near-surface wind regime.The dunes have developed in a wide inter-dune corridor between high compound longitudinal ridges in China＇s Taklimakan Desert.The surface sediments at four developmental stages of the crescent dunes were primarily composed of fine sands,followed by very fine and medium sands.Mean grain sizes ranged from 2.8 to 3.1 φ,with a unimodal distribution.The sands were moderately well-sorted,their distribution varied from platykurtic to very platykurtic,and symmetrical or skewed towards the fine particles.From oval sand piles through shield and incipient crescent dunes to mature crescent dunes,incipient grain size gradually increased,particles became finer,sorting became better,kurtosis and skewness increased.Grain sizes on the surface layer became coarser upwards from the toe of the windward slope and then became finer towards the bottom of the leeward slope.We found that the coarsest particles at different positions at the four developmental stages were different.The coarsest particles were distributed at the top of the oval sand piles and shield dunes,versus at the middle of the windward slope of the incipient and mature crescent dunes.Correlations between the mean grain size and other grain size parameters showed that as mean grain size became finer,sorting became better and kurtosis became wider,but skewness changed only slightly.In addition,grain size variation in the surface sediments correlated with the movement speed of the dunes in the study area.In the open ground among tall-complex longitudinal ridges in the hinterland of the Taklimakan Desert where aeolian environment is characterized by comparatively strong wind and unsaturated sand flow,faster dune movement corresponded to coarser grain size.
基金supported by the National Natural Science Foundation of China(Grant No.51079024)the National Foundation for Creative Research Groups(Grant No.50921001)
文摘A series of experiments on the instability of steeP water wave trains in water with finite water depths and infinite water depths in a wide wave basin were performed. It was found that under the coupled development of modulational instability and class-Ⅱ instability, the initial two-dimensional steep wave trains evolved into three＇dimensional crescent waves, followed by the occurrence of disordered water surfaces, and that the wave energy transferred to sidebands in the amplitude spectrum of the water surface elevation. The results also show that water depth has a significant effect on the growth of modulational instability and the evolutiin of crescent waves. The larger the water depth, the more quickly the modulational instability suppresses class-II instability.
基金supported by the National Natural Science Foundation of China(41271265,31570498,31300411)the Science and Technology Projects in Gansu Province(1304NKCA135)the Foundation of China Scholarship Council
文摘Desert lake, a unique oasis in desert ecosystems, harbours different bacterial communities. Thus, it is considered as a hub of bacterial diversity. In this study, bacterial diversity in the sediment of Crescent Moon Spring, Kumtag Desert, Northwest China was analyzed using high-throughput amplicon pyrosequencing analysis. The sequences of the most abundant OUTs （Operational Taxonomic Units） in the sediment of Crescent Moon Spring were compared with the sequences of those most abundant OUTs of various origins from NCBI GenBank database to detect the origins of bacteria in the sediment of Crescent Moon Spring. Also, bacterial compositions between sediment of Crescent Moon Spring and other desert and lake ecosystems （including desert lakes） worldwide were compared using cluster analysis to determine the possible factors affecting bacterial compositions. In total, 11,855 sequences were obtained and 30 phyla were identified. At the phylum level, the dominant phylum was Proteobacteria with α-Proteobacteria being the first dominant class and the second dominant phylum was Planctomycetes. Our finding that α-Proteobacteria being the first dominant class of Proteobacteria and Planctomycetes being the second dominant phyla are somewhat contradictory with reports from other desert lake sediments. This difference could be resulted from water hydration and conductivity, as well as oligotrophic conditions of Crescent Moon Spring. At the genus level, Rhodobacter, Caldilinea, Planctomyces, and Porphyrobacterwere the dominant genera in the sediment of Crescent Moon Spring. Comparisons on sequences of the most abundant OUTs （including OTU3615, OTU6535, and OTU6646） between sediment of Crescent Moon Spring and various origins from NCBI GenBank database indicate that the origins of bacteria in the sediment of Crescent Moon Spring are likely from the underground water. Furthermore, cluster analysis on comparisons of bacteria compositions between sediment of Crescent Moon Spring and other desert and lake ecosystems （including desert lakes） worldwide shows that at regional scales, bacterial compositions may be mainly affected by geographical patterns, precipitation amounts, and pH values. Collectively, our results provide new knowledge on the bacterial diversity in desert lake ecosystems.
文摘Antineutrophil cytoplasmic antibodies(ANCA) are well known to be associated with several types of vasculitis, including pauci-immune crescentic glomerulonephritis, a form of rapid progressive glomerular nephritis(RPGN). ANCA vasculitis has also been reported after administration of propylthiouracil, hydralazine, cocaine(adulterated with levimasole), allopurinol, penicillamine and few other drugs. All previously reported cases of drug-associated ANCA glomerulonephritis were in native kidneys. Sofosbuvir is a new and effective drug for hepatitis C virus infection. Here, we report a case of ANCA vasculitis and RPGN following sofosbuvir administration in a kidney transplant recipient. It also represents the first case of drug-associated ANCA vasculitis in a transplanted kidney. Further drug monitoring is necessary to elucidate the degree of association and possible causal effect of sofosbuvir and perinuclear ANCA vasculitis.
基金the National Key R&D Program of China(2018YFD1100104)the National Science Foundation of China(42071014)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y202085).
文摘The Singing Sand Mountain and Crescent Spring Scenic Spot in Dunhuang,Northwest China is a world-renowned desert attraction that is also an integral component of the Dunhuang UNESCO Global Geopark.This scenic area underwent a 30-year transformation,i.e.,from a severe sand risk with spring water threatened by sand burial due to dune deformation,to restoration of the original sand flow field and mitigation of the sand burial problem.The current paper summarizes the research on the intensive monitoring of the dynamic change of star dunes near the spring,observation of wind and sand flow movement,and then restoring the harmonic vibration of the sand particles(singing sand)that were previously silenced.The existing and prospective impacts of anthropogenic and natural forces on the deformation of the sand dunes are investigated by integrated methods,guiding the implementation of mitigating measures with significant ameliorative effects.Contrast to common sand control practices that aim to reduce wind speed and stop blown sands,our research highlights the importance of maintaining the natural wind flow field in stabilizing surrounding dunes.These mitigation measures consist of removing excessive vegetation and newly constructed buildings to recover the original wind flow field and sand transport activity.Such research and mitigation efforts ensure the scientific protection and restoration of the special desert landform,and contribute to the mutual enhancement of the conservation and exploitation of this desert scenic spot and similar sites.
文摘AIM To study the usefulness of orbital ultrasonography in the diagnosis of papilledema.METHODS Fifty patients who were referred to the neurophthalmology clinic and clinically suspected to have papilledema were selected. Thorough, clinical examination with slitlamp biomicroscopy and visual acuity assessment was done. These patients underwent ultrasonography to demonstrate the crescent sign. The patients were further evaluated with the neurologist and magnetic resonance imaging(MRI) thus confirming the diagnosis of papilledema. The results of our ultrasonographic evaluation were correlated with final diagnosis after thorough clinical evaluation, imaging and the neurologist's opinion.RESULTS Out of 50 patients diagnosed having papilledema on MRI, 46(92%) showed crescent sign on B scan ultrasonography. Headache was most common presenting complaint in 47(94%) and idiopathic intracranial hypertension was most common underlying cause of papilledema in 30(60%) cases.CONCLUSION"Crescent sign" seen on ultrasonography is a sensitive tool for diagnosis of papilledema. It is cost effective, less cumbersome and effective tool to differentiatebetween papilledema and pseudo papilledema before subjecting the patients to costly investigations like MRI. A positive crescent sign should always be followed by MRI to find out the cause of papilledema.
基金funded by the National Natural Science Foundation of China(11402190)the China Postdoctoral Science Foundation(2014M552443)the Natural Science Foundation of Shaanxi Province(2013JQ2001)
文摘This paper studies the evolution of crescent-shaped dune under the influence of injected flux. A scaling law and a wind tunnel experiment are carried out for comparison. The experiment incorporates a novel image processing algorithm to recover the evolutionary process. The theoretical and experimental results agree well in the middle stage of dune evolution, but deviate from each other in the initial and final stages, suggesting that the crescent-shaped dune evolution is intrinsically scale-variant and that the crescent shape breaks down under unsaturated condition.
文摘The Arab Spring is supposed to be the Arab world’s great changes and turmoil,but Iran has repeatedly become the focus in the following changes.Whether it is in the Syrian civil war,or strikes against ISIS,or the Qatar crisis,Iran repeatedly appeared.There are different attitudes towards Iran’s behavior.The Trump administration holds the opinion that Iran is
文摘Here two cases of renal failure occurring in pregnancy were reported,with biopsy-proven pauci-immune crescentic glomerulonephritis at postpartum.It is most rare that pauci-immune crescentic glomerulonephritis as the cause of renal failure in pregnancy.Their renal function could remain stable for some time due to timely and appropriate treatment.Therefore,the pregnant and maternal who have the performance of renal impairment should be closely tracked their blood pressure,urinary protein and renal function,if necessary,execute renal biopsy,for a clear and accurate pathological diagnosis is of great significance to grasp the opportunity of treatment.But the long-term prognosis is still poor.
文摘Objective To study the significance and distribution of renal infiltrating cells, including monocytes (CD68+ cells), proliferative cell nuclear antigen positive cells (PCNA+ cells), CD4+ and CD8+ cells in diffuse crescent glomerulonephritis (DCGN). Methods Fifty-six patients with DCGN were studied, including 10 cases of anti-glomerular basement membrane (GBM)-type Ⅰ DCGN, 26 immune complex-type Ⅱ DCGN, and 20 cases of pauci-immune-type Ⅲ DCGN. Glomerular and interstitial infiltrates of CD68+ and PCNA+ cells, and interstitial infiltrates of CD4+ and CD8+ cells were detected by using four-layer PAP methods. Results There was a significant increase of renal infiltrating CD68+, PCNA+, CD4+ and CD8+ cells in patients with DCGN compared with that in normal controls. In patients with type Ⅰ DCGN, there was a higher number of renal infiltrating CD68+ and PCNA+ cells than that in patients with type Ⅱ and Ⅲ DCGN. A glomerular infiltrates of CD68+ and PCNA+ cells correlated with the interstitial infiltrates of CD4+ cells in type Ⅰ or Ⅲ DCGN patients. In lupus DCGN patients, the numbers of renal infiltrating CD68+ and PCNA+ cells were similar to vasculitis or type Ⅲ DCGN patients.Conclusion These findings demonstrate that the renal infiltrates of CD68+ and PCNA+ cells play an important role in patients with DCGN, that the infiltrates of CD4+ cells correlate with the infiltrates of CD68+ and PCNA+ cells may be an active marker of DCGN, and that cell-mediated immunity may contribute to crescent formation in lupus DCGN patients.
基金This study was supported by Clinical Medicine Science and Technology Project of Jiangsu Province (BL2014007).
文摘Background MicroRNA-29b(miR-29b)has been suggested to possess pro-inflammatory activity,which can partially be explained by the repression of tumor necrosis factor alpha protein three antibody(TNFAIP3).Meanwhile,it also promotes thyroid cell proliferation via Smad signaling pathways.The present study aimed to elucidate the role of miR-29b in Henoch Sch(o)nlein purpura nephritis(HSPN)and its underlying molecular mechanism in angiotensinⅡ(AngⅡ)-induced human glomerular mesangial cell(HGMC)activation.Methods We evaluated miR-29b expression in 35 HSPN renal tissues based on crescent formation,glomerular sclerosis,interstitial fibrosis,thrombosis formation and capillary loop necrosis.Meanwhile,HGMCs were cultured,treated with AngⅡand then transfected with LV-hsa-miR-29b-1 to induce miR-29b overexpression or LV-hsa-miR-29b-3p-inhibition to inhibit miR-29b expression.Finally,we examined the effects of miR-29b on cell proliferation and release of inflammatory mediators.Results We observed that miR-29b expression was significantly higher in the crescent group than in the no crescent group.MiR-29b overexpression induced the release of intercellular adhesion molecule-1,interleukin-1β(IL-1β),IL-6,IL-8,the increase of CyclinA2,CyclinD 1,and cell proliferation.It also could inhibit the expressions of TNFAIP3 and NF-kappa-B-repressing factor(NKRF).Correspondingly,miR-29b inhibition produced the opposite effects and increased the expression of TNFAIP3 and NKRF.Conclusion MiR-29b expression is altered in crescent formation of HSPN and accelerates AngⅡ-induced mesangial cell proliferation and release of inflammatory mediators.
文摘Infective endocarditis （IE） is associated with poor prognosis and higher mortality. IE-induced glomerulonephritis, especially crescentic glomerulonephritis （IE-CGN） with renal dysfunction, is an independent risk factor for mortality For the treatment of IE-CGN, many therapeutic strategies including antibiotics alone, antibiotics combined with corticosteroid, immunosuppressive agents, plasmapheresis, or cardiac surgery have been applied and obtained various results.C21 Here, we reported a case of CGN with progressive renal failure secondary to IE in which the renal function was dramatically improved by the treatment of surgical valve replacement and antibiotics.
文摘Objective To investigate retrospectively the incidence, distribution of primary disease and clinicopathologic characteristics of diffuse crescentic glomerulonephritis (DCGN) in Chinese patients.Methods One hundred and seventy-two consecutive patients diagnosed as having DCGN out of 9828 cases of non-transplanting renal biopsies over sixteen years, were studied. DCGN is categorized into three types according to immunopathologic characteristics. The incidence of this disease, its primary diseases, clinical characteristics and serum antineutrophil cytoplasmic antibodies (ANCAs) were analyzed.Results The distribution of patients among the three classifications was 8. 7% type Ⅰ , 68. 6% type Ⅱ and 22. 7% type Ⅲ. Clinically, the majority of patients (69.8%) presented rapidly progressive glomerulonephritis (RPGN), but 30. 2% manifested a chronic nephritic syndrome or chronic renal failure. In terms of related conditions, 93% were anemic, 61. 6% had hypertension, 50. 6% oliguria, 45.3% nephrotic syndrome, 43% uremic syndrome and 39.5% displayed gross hematuria. Those patients who were positive in serum for ANCAs had predominantly type Ⅲ DCGN. Two cases with anti-GBM-antibody crescentic glomerulonephritis and three with lupus nephritis were also positive for ANCAs in serum.Conclusion DCGN is not rare in Chinese patients. A majority of patients in our study presented with RPGN, but 30. 2% manifested a chronic renal failure. Lupus patients with DCGN that were positive for ANCAs had more severe vasculitic lesions.
文摘Objective To evaluate the significance of serum anti neutrophil cytoplasmic antibodies (ANCAs) and the effects of immune suppressive treatments on its activity in patients with pauci immune crescentic glomerulonephritis (PICGN) Methods Serum ANCAs and myeloperoxidase (MPO) ANCA were detected by indirect immunofluorescence and enzyme linked immuno^sorbent assay (ELISA) methods respectively, and the renal tissues infiltrating cells including CD4 +, CD8 +, CD68 + and PCNA + cells were determined by four layer peroxidase antiperoxidase (PAP) method The clinical manifestations, pathologic features and immune pathologic changes in patients with positive ANCAs were compared with that in patients with negative ANCAs The effects of immune suppressive therapy on clinic and pathologic changes as well as ANCAs activity were also investigated in ANCAs positive and ANCAs negative patients Results Both of clinic active manifestations such as the degree of hematuria, rapidly progressive renal failure and pathologic active features including segmental capillary necrosis and vasculitis were much common in patients with positive ANCAs as compared with that in patients with negative ANCAs The number of infiltrating cells in renal tissue, especially CD4 + cells, was markedly higher in ANCAs positive patients than that in ANCAs negative patients The effects of immune suppressive therapy were also much better in patients with positive ANCAs than that in patients with negative ANCAs Conclusion Serum ANCAs is not only a marker for diagnosis of systemic vasculitis, but also a sensitive predictor for evaluation of diseases' activity and treatment in patients with PICGN The good effect of immune suppressive treatments on patients with PICGN is partially associated with the degree of ANCAs activity
