检索结果-南通市图书馆

Shuram-Wonoka carbon isotope excursion:ediacaran revolution in the world ocean's meridional overturning circulation

Geoscience Frontiers 2018年第2期9卷 391-402页

作者： George e.Williams Phillip W.schmidt Department of earth Sciences University of Adelaide Magneticearth

The late ediacaran Shuram-Wonoka excursion, with δ^(13)C_(carb) values as low as-12‰(PDB) in marineshelf deposits and spanning up to 10 Myr, is the deepest and most protracted δ^(13)C_(carb) negative anomaly recognised in earth history. The excursion formed on at least four continents in low(≤32°) palaeolatitudes, and in China is associated with a major phosphogenic event. Global and intrabasinal correlation, magnetostratigraphy, isotope conglomerate tests and further geochemical data are consistent with a primary or syn-depositional origin for the excursion. Continental-margin phosphorites are generated by oceanic upwelling driven by surface winds, and δ^(13)C_(carb) negative anomalies are explicable by oceanic upwelling of 13 C-depleted deep oceanic waters, arguing that a feature common to these exceptional ediacaran events was unprecedented perturbation of the world ocean. These events occurred during the transition from an alien Proterozoic world marked by low-palaeolatitude glaciation near sea level and strong seasonality to the familiar Phanerozoic earth with circum-polar glaciation and temperate climate, suggesting that the Shuram-Wonoka excursion is related to this profound change in earth's climate system. Of various hypotheses for Proterozoic low-palaeolatitude glaciation, only the high obliquity(>54°) hypothesis, which posits secular decrease in obliquity to near the present-day value(23.5°) during the ediacaran, predicts an unparalleled revolution in the ediacaran world ocean. The obliquity controls the sense of the world ocean's meridional overturning circulation, which today is driven by the sinking of cold, dense water at the poles and upwelling driven by zonal surface *** the decreasing obliquity passed the critical value of 54° during the ediacaran the meridional temperature gradient reversed, with the equator becoming warmer than the poles and Hadley lowlatitude(eric zonal circulation reversing. This reversal of the temperat

关键词： ediacaran Shuram-Wonoka carbon isotope excursion Oceanic meridional circulation Atmospheric circulation Proterozoic paleoclimate Obliquity of the ecliptic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Long-term survivor of metastatic squamous-cell head and neck carcinoma with occult primary after cetuximab-based chemotherapy:A case report

引用

World Journal of Clinical Cases 2021年第24期9卷 7092-7098页

作者： Christina Große-Thie Claudia Maletzki Christian Junghanss Kathie schmidt Department of Medicine Clinic III-HematologyOncologyPalliative MedicineRostock University Medical CenterRostock 18057Germany

BACKGROUND Cancer of unknown primary(CUP)is a histological proven malignant tumor whose origin cannot be detected despite careful *** cervical lymph node metastases in CUP(80%)will originate from head and neck sites,and 15%show infiltration of squamous carcinoma *** survival rates of CUP are poor:The 5-year-survival rate ranges from 10%to 15%.First-line treatment recommendation for advanced,inoperable squamous cell carcinoma of head/neck(HNSCC)was cetuximab plus platinum-fluorouracil chemotherapy until recently,when checkpoint inhibitors proved clinically beneficial *** SUMMARY Here,we report a case of a 42-year-old female patient with cervical and abdominal lymph node and distant bone metastases of an occult primary of the head and neck(squamous cell carcinoma,human papillomavirus positive).The cancer was diagnosed during pregnancy 10 years ago,and after giving birth,the patient was treated with cetuximab plus platinum-fluorouracil chemotherapy achieving complete remission(CR).CR lasted 26 mo when new metastases(abdominal lymph node,lumbar vertebral body)*** manifestations were *** then on,the patient has not received any further treatment,and her disease has remained *** years after the initial cancer diagnosis,the patient is still alive and in good health,representing an exceptional case of *** This case illustrates the exceptional clinical course and benefits of combined therapy approaches in advanced metastatic HNSCC with occult primary.

关键词： Squamous cell carcinoma of the head and neck Cancer of unknown primary Long-term survival Cetuximab Metastases Case report

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Strongly seasonal Proterozoic glacial climate in low palaeolatitudes:Radically different climate system on the pre-ediacaran earth

引用

Geoscience Frontiers 2016年第4期7卷 555-571页

作者： George e.Williams Phillip W.schmidt Grant M.Young Department of earth Sciences University of AdelaideSA 5005Australia CSIRO Mineral Resources Flagship PO Box 52North RydeNSW 16FOAustralia Department of earth Sciences University of Western OntarioLondonOntario N6A 5B7Canada

Proterozoic （pre-ediacaran） glaciations occurred under strongly seasonal climates near sea level in low palaeolatitudes. Metre-scale primary sand wedges in Cryogenian periglacial deposits are identical to those actively forming, through the infilling of seasonal （winter） thermal contraction-cracks in perma- frost by windblown sand, in present-day polar regions with a mean monthly air temperature range of 40 ~C and mean annual air temperatures of -20 ~C or lower. Varve-like rhythmites with dropstones in Proterozoic glacial successions are consistent with an active seasonal freeze-thaw cycle. The seasonal （annual） oscillation of sea level recorded by tidal rhythmites in Cryogenian glacial successions indicates a significant seasonal cycle and extensive open seas. Palaeomagnetic data determined directly for Prote- rozoic glacial deposits and closely associated rocks indicate low palaeolatitudes： Cryogenian deposits in South Australia accumulated at 〈10% most other Cryogenian deposits at 〈20~ and Palaeoproterozoic deposits at 〈15~ palaeolatitude. Palaeomagnetic data imply that the Proterozoic geomagnetic field approximated a geocentric axial dipole, hence palaeolatitudes represent geographic latitudes. The Cry- ogenian glacial environment included glacier-flee, continental permafrost regions with ground frozen on a kyr time-scale, aeolian sand-sheets, extensive and long-lived open seas, and an active hydrological cycle. This palaeoenvironment confiicts with the ＇snowball earth＇ and ＇slushball earth＇ hypotheses, which cannot accommodate large seasonal changes of temperature near the equator. Consequently, their proponents have attempted to refute the evidence for strong seasonality by introducing Popperian ＇auxiliary assumptions＇. However, non-actualistic arguments that the Cryogenian sand wedges indicate diurnal or weakly seasonal temperature changes are based on misunderstandings of periglacial pro- cesses. Modelling of a strongly seasonal climate for a frozen-over ear

关键词： Proterozoic Glaciation Periglacial structures Varves Paleoclimate Paleomagetism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thermal evolution of an ancient subduction interface revealed by Lue Hf garnet geochronology, Halilba■? Complex(Anatolia)

引用

Geoscience Frontiers 2019年第1期10卷 127-148页

作者： Amaury Pourteau erik e.Scherer Simon Schorn Rebecca Bast Alexander schmidt Lisa ebert Institut für erd- und Umweltwissenschaften Universit?t Potsdam earth Dynamics Research Group ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS) The Institute for Geoscience Research (TIGeR) School of Earth and Planetary Sciences Curtin University Münster Isotope Research Centre Institut für Mineralogie Westf?lische Wilhelms-Universit?t Münster Department of Geological Sciences University of Cape Town Institut für Geologie und Mineralogie Universit?t zu K?ln

The thermal structure of subduction zones exerts a major influence on deep-seated mechanical and chemical processes controlling arc magmatism, seismicity, and global element cycles. Accretionary complexes exposed inland may comprise tectonic blocks with contrasting pressureetemperature(Pe T)histories, making it possible to investigate the dynamics and thermal evolution of former subduction interfaces. With this aim, we present new Lue Hf geochronological results for mafic rocks of the Halilbag?Complex(Anatolia) that evolved along different thermal gradients. Samples include a lawsoniteeepidote blueschist, a lawsoniteeepidote eclogite, and an epidote eclogite(all with counter-clockwise Pe T paths),a prograde lawsonite blueschist with a "hairpin"-type Pe T path, and a garnet amphibolite from the overlying sub-ophiolitic metamorphic sole. equilibrium phase diagrams suggest that the garnet amphibolite formed at w0.6 -0.7 GPa and 800 -850℃, whereas the prograde lawsonite blueschist records burial from 2.1 GPa and 420℃ to 2.6 GPa and 520℃. Well-defined Lue Hf isochrons were obtained for the epidote eclogite(92.38 ± 0.22 Ma) and the lawsoniteeepidote blueschist(90.19 ± 0.54 Ma),suggesting rapid garnet growth. The lawsoniteeepidote eclogite(87.30 ± 0.39 Ma) and the prograde lawsonite blueschist(ca. 86 Ma) are younger, whereas the garnet amphibolite(104.5 ± 3.5 Ma) is *** data reveal a consistent trend of progressively decreasing geothermal gradient from granulite-facies conditions at ~104 Ma to the epidote-eclogite facies around 92 Ma, and the lawsonite blueschist-facies between 90 Ma and 86 Ma. Three Lue Hf garnet dates(between 92 Ma and 87 Ma) weighted toward the growth of post-peak rims(as indicated by Lu distribution in garnet) suggest that the HP/LT rocks were exhumed continuously and not episodically. We infer that HP/LT metamorphic rocks within the Halilbag?Complex were subjected to continuous return flow, with "warm" rocks being exhumed during the tectonic bur

关键词： Subduction Lu/Hf dating of garnet Metamorphic sole eclogite Blueschist Lawsonite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comparison between the quality and function of sperm after semen processing with two different methods

引用

Asian Journal of Andrology 2001年第2期3卷 125-130页

作者： M.e.Hammadeh P.M.Zavos P.Rosenbaum W.schmidt Dept. of Obs/Gyn University of Saarland 66421 Homburg/Saar GermanyAndrology Insitute of America and Kentucky Center for Reproductive Medicine & IVF Lexington KY USADept. of Obs/Gyn University of Saarland 66421 Homburg/Saar GermanyDept. of Obs/Gyn University of Saarland 66421 Homburg/Saar Germany

Aim: To compare the recovery rate of morphologically normal and chromatin condensed spermatozoa from native se-men samples using the SpermPrep^(TM) filtration columns and Percoll gradient centrifugation and to determine the influenceof the two processing techniques on fertilization and pregnancy rates in an IVF-eT program. Methods: Sixteen se-men samples obtained from patient's husband were included in this study. each was divided into two aliquots. The firstaliquot was processed with SpermPrep^(TM) filtration columns and the second, Percoll gradient centrifugation. Smears weremade before and after semen processing with both methods for the evaluation of chromatin condensation (chromomycineCMA3) as well as morphology (strict criteria) of spermatozoa. One hundred and seventy oocytes were retrieved fromthe patients and the oocytes from each patient were subdivided into two sets : one set was inseminated using spermatozoaprocessed with SpermPrep^(TM) and the other inseminated after semen processing with Percoll gradient centrifugation. Re-sults: The Percoll method yielded a significantly higher percentage of chromatin condensed (90.8 ±6.5% vs 82.3±8.8%, P = 0.017) and morphologically normal spermatozoa (12.9±7.4% vs 6.9±4.8%, P =0.001) in com-parison to SpermPrep^(TM). Whereas, sperm count recovery rate was significantly higher after the use of SpermPrep^(TM) thanafter the Percoll gradient centrifugation. The fertilization rate was similar between the two methods. Conclusion:Semen processing with Percoll should be recommended for intracytoplasmic sperm injection as the natural selection isbypassed and the SpermPrep^(TM) technique could be recommended for IVF and IUI programs as the sperm concentrationplays a more significant role in these procedures.

关键词： sperm semen processing spermPrep^(TM) percoll gradient centrifugation IVF

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

entangled-photons generation with quantum dots

引用

Chinese Physics B 2018年第2期27卷 140-153页

作者：李远丁飞 Oliver G schmidt Institute for Integrative Nanosciences IFW Dresden HelmholtzstraBe 20. 01069 Dresden. Germany Integrative for Solid State Physics. Leibniz University of Hunnover. AppelstBe 2.30 167 Hannovel Germany

entanglement between particles is a crucial resource in quantum information processing, an important example of which is the exploitation of entangled photons in quantum communication protocols. Among the different available sources of entangled photons, semiconductor quantum dots （QDs） excel owing to their deterministic emission properties, potential for electrical injections, and direct compatibility with semiconductor manufacturing techniques. Despite the great promises, QD-based sources at＇e far from being ideal. In particular, such sources present several critical issues, which require the overcoming of challenges pertaining to spectral tunability, entanglement fidelity, photon indistinguishability and brightness. In this article, we will discuss the potential solutions to these problems and review the recent progress in the field.

关键词： quantum information entangled-photon source quantum dots

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Incorporating shape constraints in generalized additive modelling of the height-diameter relationship for Norway spruce

引用

Forest ecosystems 2016年第2期3卷 112-125页

作者： Natalya Pya Matthias schmidt Department of Mathematics School of Science and TechnologyNazarbayev University The Northwest German Forest Research Station Department of Forest Growth

Background： Measurements of tree heights and diameters are essential in forest assessment and modelling. Tree heights are used for estimating timber volume, site index and other important variables related to forest growth and yield, succession and carbon budget models. However, the diameter at breast height （dbh） can be more accurately obtained and at lower cost, than total tree height. Hence, generalized height-diameter （h-d） models that predict tree height from dbh, age and other covariates are needed. For a more flexible but biologically plausible estimation of covariate effects we use shape constrained generalized additive models as an extension of existing h-d model approaches. We use causal site parameters such as index of aridity to enhance the generality and causality of the models and to enable predictions under projected changeable climatic conditions. Methods： We develop unconstrained generalized additive models （GAM） and shape constrained generalized additive models （SCAM） for investigating the possible effects of tree-specific parameters such as tree age, relative diameter at breast height, and site-specific parameters such as index of aridity and sum of daily mean temperature during vegetation period, on the h-d relationship of forests in Lower Saxony, Germany. Results： Some of the derived effects, e.g. effects of age, index of aridity and sum of daily mean temperature have significantly non-linear pattern. The need for using SCAM results from the fact that some of the model effects show partially implausible patterns especially at the boundaries of data ranges. The derived model predicts monotonically increasing levels of tree height with increasing age and temperature sum and decreasing aridity and social rank of a tree within a stand, The definition of constraints leads only to marginal or minor decline in the model statistics like AIC An observed structured spatial trend in tree height is modelled via 2-dimensional surface fitting. Conclusions： We

关键词： Height-diameter curve Norway spruce Shape constrained additive models Impact of climate change,Varying coefficient models

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development of a mechanism-based pharmacokinetic/pharmacodynamic model to characterize the thermoregulatory effects of serotonergic drugs in mice

引用

Acta Pharmaceutica Sinica B 2016年第5期6卷 492-503页

作者： Xi-Ling Jiang Hong-Wu Shen Donald e.Mager Stephan schmidt Ai-Ming Yu Department of Pharmaceutical Sciences School of Pharmacy and Pharmaceutical SciencesUniversity at BuffaloThe State University of New York Department of Pharmaceutics Center for Pharmacometrics and Systems PharmacologyUniversity of Florida Department of Biochemistry & Molecular Medicine UC Davis School of Medicine2700 Stockton Boulevard

We have shown recently that concurrent harmaline,a monoamine oxidase-A inhibitor(MAOI),potentiates serotonin(5-HT) receptor agonist 5-methoxy-N,N-dimethyltryptamine(5-Me O-DMT)-induced *** objective of this study was to develop an integrated pharmacokinetic/pharmacodynamic(PK/PD) model to characterize and predict the thermoregulatory effects of such serotonergic drugs in *** thermoregulation was described by a mechanism-based indirect-response model with adaptive feedback ***-induced hypothermia and 5-Me O-DMT–elicited hyperthermia were attributable to the loss of heat through the activation of 5-HT1 Areceptor and thermogenesis via the stimulation of 5-HT2 Areceptor,*** serotonergic 5-Me O-DMT–induced hyperthermia was readily distinguished from handling/injection stress-provoked hyperthermic *** PK/PD model was able to simultaneously describe all experimental data including the impact of drug-metabolizing enzyme status on5-Me O-DMT and harmaline PK properties,and drug- and stress-induced simple hypo/hyperthermic and complex biphasic ***,the modeling results revealed a 4-fold decrease of apparent SC_(50) value(1.88–0.496 mmol/L) for 5-Me O-DMT when harmaline was co-administered,providing a quantitative assessment for the impact of concurrent MAOI harmaline on 5-Me ODMT–induced *** addition,the hyperpyrexia caused by toxic dose combinations of harmaline and 5-Me O-DMT were linked to the increased systemic exposure to harmaline rather than5-Me O-DMT,although the body temperature profiles were mispredicted by the *** results indicate that current PK/PD model may be used as a new conceptual framework to define the impact of serotonergic agents and stress factors on thermoregulation.

关键词： PK/PD model Thermoregulation Indolealkylamine Serotonin Monoamine oxidase-A inhibitor Stress

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Traceless enzymatic protein synthesis without ligation sites constraint

引用

National Science Review 2022年第5期9卷 108-118页

作者： Ruifeng Li Marcel schmidt Tong Zhu Xinyu Yang Jing Feng Yu'e Tian Yinglu Cui Timo Nuijens Bian Wu CAS Key Laboratory of Microbial Physiological and Metabolic engineering State Key Laboratory of Microbial ResourcesInstitute of Microbiology Chinese Academy of Sciences University of Chinese Academy of Sciences Fresenius Kabi iPSUM I&D Center EnzyPep B.V.

Protein synthesis and semisynthesis offer immense promise for life sciences and have impacted pharmaceutical *** absence of a generally applicable method for traceless peptide conjugation with a flexible choice of junction sites remains a bottleneck for accessing many important synthetic targets,*** we introduce the PALMe(protein activation and ligation with multiple enzymes) platform designed for sequence-unconstrained synthesis and modification of *** upstream activating modules accept and process easily accessible synthetic peptides and recombinant proteins,avoiding the challenges associated with preparation and manipulation of activated peptide ***,the downstream coupling module provides comprehensive solutions for sequential peptide condensation,cyclization and protein N/C-terminal or internal *** practical utility of this methodology is demonstrated by synthesizing a series of bioactive targets ranging from pharmaceutical ingredients to synthetically challenging *** modular PALMe platform exhibits unprecedentedly broad accessibility for traceless protein synthesis and functionalization,and holds enormous potential to extend the scope of protein chemistry and synthetic biology.

关键词： protein synthesis traceless peptide ligation biocatalysis synthetic biology chemical biology

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Low-power emerging memristive designs towards secure hardware systems for applications in internet of things

引用

Nano Materials Science 2021年第2期3卷 186-204页

作者： Nan Du Heidemarie schmidt Ilia Polian Department Nano Device technology Fraunhofer Institute for Electronic Nano SystemsTechnologie-Campus 309126ChemnitzGermany Faculty of electrical engineering and Information technology Chemnitz University of Technology(TU Chemnitz)Straße der Nationen 6209126ChemnitzGermany Department of Quantum Detection Leibniz Institute of Photonic Technology(IPHT)Albert-Einstein-Str.907745JenaGermany Institute for Solid State Physics Friedrich Schiller University JenaFürstengraben 107743JenaGermany Institute of Computer engineering and Computer Architecture(ITI) University of StuttgartPfaffenwaldring 4770569StuttgartGermany

emerging memristive devices offer enormous advantages for applications such as non-volatile memories and inmemory computing(IMC),but there is a rising interest in using memristive technologies for security applications in the era of internet of things(IoT).In this review article,for achieving secure hardware systems in IoT,lowpower design techniques based on emerging memristive technology for hardware security primitives/systems are *** reviewing the state-of-the-art in three highlighted memristive application areas,*** non-volatile memory,memristive reconfigurable logic computing and memristive artificial intelligent computing,their application-level impacts on the novel implementations of secret key generation,crypto functions and machine learning attacks are explored,*** the low-power security applications in IoT,it is essential to understand how to best realize cryptographic circuitry using memristive circuitries,and to assess the implications of memristive crypto implementations on security and to develop novel computing paradigms that will enhance their *** review article aims to help researchers to explore security solutions,to analyze new possible threats and to develop corresponding protections for the secure hardware systems based on low-cost memristive circuit designs.

关键词： Memristive technology Nanoelectronic device Low-power consumption Miniaturization Nonvolatility Reconfigurability In memory computing Artificial intelligence Hardware security primitives Machine learning-related attacks and defenses

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：