孟鲁司特联合信必可在重度哮喘中的治疗与干预效果分析

目的对孟鲁司特联合信必可对重度哮喘治疗与干预效果进行探讨。方法研究对象为2015年1月-2017年1月于本院接受治疗的80例重度哮喘患者,将这80例患者随机均分为对照组和观察组。将信必可治疗应用于对照组,将孟鲁司特+信必可治疗应用于观察组,对两组实验数据进行观察对比,对孟鲁司特联合信必可在重度哮喘治疗与干预效果进行分析。结果观察组对于重度哮喘患者的临床治疗效果优于观察组,患者的临床改善状况也是观察组更优,两组对比差异较大,统计学意义明显(P<0.05)。结论将孟鲁司特联合信必可应用于重度哮喘的临床治疗有明显效果,对患者临床症状改善有推动作用,值得临床推广。

利用Picarro测试石笋包裹体水氢、氧同位素的方法

基于当前石笋包裹体水提取测试过程中面临的制约条件,本研究设计了用于提取石笋包裹体水的真空装置,将其与水同位素分析仪Picarro L2140-i相连接组成石笋包裹体水氢、氧同位素(δD、δ18O)测试系统.该系统能够快速地提取石笋包裹体中的水,并对其δD和δ18O的值进行测量.包裹体水真空提取装置使用了以高压气缸为驱动的破碎研磨器,具有良好的破碎效果;在120°C真空条件下破碎获得的包裹体水随后被高纯氮气带入到Picarro L2140-i中进行测量分析.为了验证包裹体水测试系统的可靠性和准确性,本研究分别将石笋包裹体水真空提取装置以及Picarro液态水自动进样器与Picarro L2140-i主机连接,对相同的水样品进行了对比测试.两种方法测得的δ18O和δD值在误差范围内接近.使用该系统对东亚季风区石笋样品进行的测试结果显示:石笋包裹体水的δ18O和δD值分布在全球大气降水线附近,表明测试过程中分馏作用较小;包裹体含水量对测试精度有一定影响,对于水汽浓度为2500~50000 ppm(1 ppm=1μL/L)的样品,δ18O、δD的标准差分别为0.5‰、2‰,与同类型系统相当.研究结果表明该系统能如实测量石笋包裹体水的δ18O和δD值,将为利用水-碳酸钙平衡分馏方程重建古温度提供重要的技术支撑.

Great flood in the middle-lower Yellow River reaches at 4000 a BP inferred from accurately-dated stalagmite records

Recently,Wu et al.[1]suggested an earthquake-induced landslide dam outburst flood on the eastern Tibetan Plateau at 1920BCE(3870 a BP,BP denotes year before 1950 CE)caused the Great Flood in the middle-lower Yellow River reaches,and resulted in the founding of Xia Dynasty at 3850 a BP.This age is$150–300younger than the previously estimated age of the Xia Dynasty[2].While the geological evidence of the outburst flood。

超级大旱与史前丝绸之路上的文化交流

中亚干旱区是丝绸之路的核心区,也是史前人类扩散和东西方文化交流的重要通道.该区气候干旱,植被和生态群落受制于水文因素.由于缺乏精确年代控制的高分辨率古气候记录,中亚地区全新世水文变化及极端干旱事件在史前人口迁移和跨欧亚大陆文化交流中扮演的角色还不清楚.本文基于来自吉尔吉斯斯坦的石笋多指标记录,重建了中亚干旱区目前年代最精确(测年误差~6‰)、分辨率最高(~3年)、涵盖中晚全新世的降水变化序列.结果显示在5820~5180 a BP期间,该区存在一次持续时间为640年的超级干旱事件,主要受西风带北移的影响.这次干旱事件对中亚史前文化的发展产生了重要影响,很可能阻碍了史前东西方文化沿中亚绿洲路线上的相向扩散,使得最早的跨欧亚大陆文化交流在5000~4000 a BP沿着北方草原路线开展.随着大干旱后降水的逐渐增加和生态环境的恢复,中亚绿洲和河谷中增加的定居人口促进了不同绿洲之间的相互联系,进一步在4000~3000 a BP开辟了跨大陆文化交流的史前丝绸之路,为历史时期丝绸之路的最终开通奠定了基础.

Application of Avaatech X-ray fluorescence core-scanning in Sr/Ca analysis of speleothems

Application of X-ray fluorescence core-scanning(XRF-CS) on both marine and lake sediments has achieved remarkable results. However, its application has not been widely extended to the research on speleothems. In this study, we measure the Sr abundance and the Sr/Ca ratios of three stalagmites(two aragonite stalagmites, one calcite stalagmite) using the state-of-the-art fourth-generation Avaatech high-resolution XRF core scanner. Through comparisons among different scan paths and among different scan resolutions, as well as comparisons with inductively coupled plasma optical emission spectrometer(ICP-OES), Itrax XRF, and Artax XRF results, we confirm that the Avaatech XRF core scanner could precisely, quickly, and nondestructively analyze the high-resolution Sr abundance of speleothems. Furthermore, we combine the stalagmite δ^(18)O records to explore the paleoclimatic significance of the measured stalagmite Sr/Ca.

Orbital-scale Asian summer monsoon variations:Paradox and exploration

The Asian summer monsoon(ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in understanding variations on a wide range of timescales, yet several significant issues remain unresolved. Of note are two long-standing problems concerning orbital-scale variations of the ASM.(1) Chinese loess magnetic susceptibility records show a persistent glacial-interglacial dominated ~100 kyr(thousand years) periodicity, while the cave oxygen-isotope(δ18 O) records reveal periodicity in an almost pure precession band(~20 kyr periodicity)—the "Chinese 100 kyr problem".(2) ASM records from the Arabian Sea and other oceans surrounding the Asian continent show a significant lag of 8–10 kyr to Northern Hemisphere summer insolation(NHSI), whereas the Asian cave δ18 O records follow NHSI without a significant lag—a discrepancy termed the "sea-land precession-phase paradox". How can we reconcile these differences? Recent and more refined model simulations now provide spatial patterns of rainfall and wind across the precession cycle, revealing distinct regional divergences in the ASM domain, which can well explain a large portion of the disparities between the loess, marine, and cave proxy records. Overall, we also find that the loess, marine, and cave records are indeed complementary rather than incompatible, with each record preferentially describing a certain aspect of ASM dynamics. Our study provides new insight into the understanding of different hydroclimatic proxies and largely reconciles the "Chinese 100 kyr problem" and "sea-land precession-phase paradox".

A multiple-proxy stalagmite record reveals historical deforestation in central Shandong, northern China

Evaluating anthropogenic impacts on regional vegetation changes during historical time is not only important for a better understanding of the Anthropocene but also valuable in improving the vegetation-climate models.In this study,we analyzed stable isotopes(δ^18O,δ^13C)and trace elements(Mg/Ca,Sr/Ca)of a stalagmite from Huangchao Cave in central Shandong,northern China.230Th and AMS14C dating results indicate the stalagmite deposited during 174BC and AD1810,with a hiatus between AD638 and 1102.Broad similarities of theδ^18O and trace elements in the stalagmite suggest they are reliable precipitation indexes.Theδ^13C of the stalagmite,a proxy of vegetation change,was generally consistent with local precipitation and temperature variations on a centennial-scale before the 15th century.It typically varied from–9.6‰to–6.3‰,indicating climate controlled C3 type vegetation during this period.However,a persistent and marked increasing trend in theδ^13C record was observed since the 15th century,resulting inδ^13C values from–7.7‰to–1.6‰in the next four centuries.This unprecedentedδ^13C change caused by vegetation deterioration cannot be explained by climate change but is fairly consistent with the dramatically increasing population and farmland in Shandong.We suggest that the increasing deforestation and reclamation in central Shandong began to affect vegetation in the mountain region of central Shandong since the 15th century and severely destroyed or even cleared the forest during the 16th–18th century.

Metal-polyphenol-coordinated nanomedicines for Fe(II) catalyzed photoacoustic-imaging guided mild hyperthermia-assisted ferroustherapy against breast cancer

Ferroustherapy has gained great attention for anti-cancer treatment in recent years. Enlightened by temperature-mediated Fenton reaction in industrial waste water removal, we designed a iron-based polyphenol-coordinated nanomedicines for mild hyperthermia-assisted anti-cancer ferroustherapy. In brief, Fe-GA@BSA nanoparticles was synthesized by self-assembly and sorafenib(SRF) was loaded into Fe-GA@BSA to establish Fe-GA@BSA-SRF nanomedicines. The result nanomedicines can induce ferroptosis in cancer cells by accelerating Fenton reaction. And the photothermal effect of Fe-GA@BSA-SRF was used for mild hyperthermia-assisted ferroustherapy. The nanomedicines performs good anti-cancer therapeutic efficacy by inducing the production of ROS and inhibiting glutathione peroxidase 4(GPX4) expression in vitro and in vivo. Besides, the broad absorption of Fe-GA@BSA-SRF in near infrared region endows it with photoacoustic imaging ability. This study provides ideas about rational design on iron-based nanoparticles for anti-cancer ferroustherapy.

Milankovitch theory and monsoon

The widely accepted“Milankovitch theory”explains insolation-induced waxing and waning of the ice sheets and their effect on the global climate on orbital timescales.In the past half century,however,the theory has often come under scrutiny,especially regarding its“100-ka problem.”Another drawback,but the one that has received less attention,is the“monsoon problem,”which pertains to the exclusion of monsoon dynamics in classic Milankovitch theory even though the monsoon prevails over the vast low-latitude(
30N to
30S)region that covers half of the Earth’s surface and receives the bulk of solar radiation.In this review,we discuss the major issues with the current form of Milankovitch theory and the progress made at the research forefront.