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1.
Proc Natl Acad Sci U S A ; 119(51): e2210601119, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36508660

RESUMEN

Acoustic communication has played a key role in the evolution of a wide variety of vertebrates and insects. However, the reconstruction of ancient acoustic signals is challenging due to the extreme rarity of fossilized organs. Here, we report the earliest tympanal ears and sound-producing system (stridulatory apparatus) found in exceptionally preserved Mesozoic katydids. We present a database of the stridulatory apparatus and wing morphology of Mesozoic katydids and further calculate their probable singing frequencies and analyze the evolution of their acoustic communication. Our suite of analyses demonstrates that katydids evolved complex acoustic communication including mating signals, intermale communication, and directional hearing, at least by the Middle Jurassic. Additionally, katydids evolved a high diversity of singing frequencies including high-frequency musical calls, accompanied by acoustic niche partitioning at least by the Late Triassic, suggesting that acoustic communication might have been an important driver in the early radiation of these insects. The Early-Middle Jurassic katydid transition from Haglidae- to Prophalangopsidae-dominated faunas coincided with the diversification of derived mammalian clades and improvement of hearing in early mammals, supporting the hypothesis of the acoustic coevolution of mammals and katydids. Our findings not only highlight the ecological significance of insects in the Mesozoic soundscape but also contribute to our understanding of how acoustic communication has influenced animal evolution.


Asunto(s)
Ortópteros , Animales , Ortópteros/anatomía & histología , Acústica , Sonido , Audición , Insectos , Mamíferos , Evolución Biológica
2.
Proc Natl Acad Sci U S A ; 116(23): 11345-11350, 2019 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-31085633

RESUMEN

Amber is fossilized tree resin, and inclusions usually comprise terrestrial and, rarely, aquatic organisms. Marine fossils are extremely rare in Cretaceous and Cenozoic ambers. Here, we report a record of an ammonite with marine gastropods, intertidal isopods, and diverse terrestrial arthropods as syninclusions in mid-Cretaceous Burmese amber. We used X-ray-microcomputed tomography (CT) to obtain high-resolution 3D images of the ammonite, including its sutures, which are diagnostically important for ammonites. The ammonite is a juvenile Puzosia (Bhimaites) and provides supporting evidence for a Late Albian-Early Cenomanian age of the amber. There is a diverse assemblage (at least 40 individuals) of arthropods in this amber sample from both terrestrial and marine habitats, including Isopoda, Acari (mites), Araneae (spiders), Diplopoda (millipedes), and representatives of the insect orders Blattodea (cockroaches), Coleoptera (beetles), Diptera (true flies), and Hymenoptera (wasps). The incomplete preservation and lack of soft body of the ammonite and marine gastropods suggest that they were dead and underwent abrasion on the seashore before entombment. It is most likely that the resin fell to the beach from coastal trees, picking up terrestrial arthropods and beach shells and, exceptionally, surviving the high-energy beach environment to be preserved as amber. Our findings not only represent a record of an ammonite in amber but also provide insights into the taphonomy of amber and the paleoecology of Cretaceous amber forests.


Asunto(s)
Ámbar/química , Animales , Ecosistema , Bosques , Fósiles , Gastrópodos/química , Resinas de Plantas/química , Árboles/química , Microtomografía por Rayos X/métodos
3.
Ecotoxicol Environ Saf ; 217: 112274, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33930771

RESUMEN

Canonical ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and complete-nitrifying bacteria (comammox) exist in a variety of ecosystems. However, little is known about AOA, AOB and comammox or their contributions to nitrification in the soils of heavily degraded and acidic mine regions. In the present study, the activity, richness, diversity and distribution patterns of AOA, AOB and comammox in the Siding mine area were investigated. Nemerow's multifactor pollution index (PN) values indicated that the soil in all three areas in the Siding mine area was highly contaminated by Cd, Pb, Zn, Mn and Cu. The AOA, AOB and comammox amoA gene copy numbers exhibited significant positive correlations with Pb and Zn levels and PN values, which indicated that the populations of AOA, AOB and comammox underwent adaptation and reproduction in response to pollution from multiple metals in the Siding mine area. Among them, the abundance of AOA was the highest, and AOA may survive better than AOB and comammox under such severely pollution-stressed and ammonia-limited conditions. The phyla Thaumarchaeota and Crenarchaeota may play vital roles in the soil ammonia oxidation process. Unlike AOA, AOB may use soil available phosphorus to help them compete for NH3 and other limiting nutrients with AOA and heterotrophs. Moreover, soil organic matter was the main factor influencing the species diversity of AOB, the ß-diversity of AOB and comammox, and the community composition of AOA, AOB and comammox. Our research will help to explain the role and importance of AOA, AOB and comammox in the different ecological restoration regions in the Siding mine area.


Asunto(s)
Amoníaco/metabolismo , Biodegradación Ambiental , Minería , Microbiología del Suelo , Archaea/metabolismo , Bacterias/metabolismo , Betaproteobacteria/metabolismo , Biodiversidad , Ecosistema , Nitrificación , Oxidación-Reducción , Fósforo/metabolismo , Filogenia , Suelo , Contaminantes del Suelo
4.
Proc Biol Sci ; 287(1935): 20201661, 2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32933445

RESUMEN

The bivalved crustacean ostracods have the richest fossil record of any arthropod group and display complex reproductive strategies contributing to their evolutionary success. Sexual reproduction involving giant sperm, shared by three superfamilies of living ostracod crustaceans, is among the most fascinating behaviours. However, the origin and evolution of this reproductive mechanism has remained largely unexplored because fossil preservation of such features is extremely rare. Here, we report exceptionally preserved ostracods with soft parts (appendages and reproductive organs) in a single piece of mid-Cretaceous Kachin amber (approximately 100 Myr old). The ostracod assemblage is composed of 39 individuals. Thirty-one individuals belong to a new species and genus, Myanmarcypris hui gen. et sp. nov., exhibiting an ontogenetic sequence from juveniles to adults (male and female). Seven individuals are assigned to Thalassocypria sp. (Cypridoidea, Candonidae, Paracypridinae) and one to Sanyuania sp. (Cytheroidea, Loxoconchidae). Our micro-CT reconstruction provides direct evidence of the male clasper, sperm pumps (Zenker organs), hemipenes, eggs and female seminal receptacles with giant sperm. Our results reveal that the reproduction behavioural repertoire, which is associated with considerable morphological adaptations, has remained unchanged over at least 100 million years-a paramount example of evolutionary stasis. These results also double the age of the oldest unequivocal fossil animal sperm. This discovery highlights the capacity of amber to document invertebrate soft parts that are rarely recorded by other depositional environments.


Asunto(s)
Crustáceos/anatomía & histología , Genitales Masculinos , Espermatozoides , Ámbar , Animales , Artrópodos , Femenino , Fósiles , Genitales , Masculino , Reproducción , Microtomografía por Rayos X
5.
Sensors (Basel) ; 20(17)2020 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-32899244

RESUMEN

The Short-range-controlled communication system (RCC) based on a subscriber identity module (SIM) card is a replacement for the standard near-field communication (NFC) system to support near-field payment applications. The RCC uses both the low-frequency (LF) and high-frequency (HF) wireless communication system. The RCC communication distance is controlled under 10 cm. However, current RCCs suffer from compatibility issues, and the LF communication distance is lower than 0.5 cm in some phones with completely metallic shells. In this paper, we propose an improved LF communication system design, including an LF transmitter circuit, LF receiver chip, and LF-HF communication protocol. The LF receiver chip has a rail-to-rail amplifier and a self-correcting clock recovery differential Manchester decoder, which do not have the limitations of accurate gain and high system clock. The LF receiver chip is fabricated in a 0.18 µm CMOS technology platform, with a die size of 1.05 mm × 0.9 mm and current consumption of 41 µA. The experiments show that the improved RCC has better compatibility, and the communication distance reaches to 4.2 cm in phones with completely metallic shells.

6.
Sensors (Basel) ; 20(17)2020 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-32872600

RESUMEN

The Internet of Things (IoT) is an industry-recognized next intelligent life solution that increases the level of comfort, efficiency, and automation for citizens through numerous sensors, smart devices, and cloud stations connected physically. As an important application scenario of IoT, the Internet of Vehicles (IoV) plays an extremely critical role in the intelligent transportation field. In fact, the In-Vehicle Network of smart vehicles that are recognized as the core roles in intelligent transportation is currently the Controller Area Network (CAN). However, the In-Vehicle CAN bus protocol has several vulnerabilities without any encryption, authentication, or integrity checking, which severely threatens the safety of drivers and passengers. Once malicious attackers hack the vehicular gateway and obtain the access right of the CAN, they may control the vehicle based on the vulnerabilities of the CAN bus protocol. Given the severe security risk of CAN, we proposed the CANsec, a practical In-Vehicle CAN security evaluation tool that simulates malicious attacks according to major attack models to evaluate the security risk of the In-Vehicle CAN. We also show a usage case of the CANsec without knowing any information from the vehicle manufacturer.

7.
Naturwissenschaften ; 103(1-2): 2, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26715353

RESUMEN

Parasitoidism is a key innovation in insect evolution, and parasitoid insects, nowadays, play a significant role in structuring ecological communities. Despite their diversity and ecological impact, little is known about the early evolution and ecology of parasitoid insects, especially parasitoid true flies (Diptera). Here, we describe a bizarre fly, Zhenia xiai gen. et sp. nov., from Late Cretaceous Burmese amber (about 99 million years old) that represents the latest occurrence of the family Eremochaetidae. Z. xiai is an endoparasitoid insect as evidenced by a highly developed, hypodermic-like ovipositor formed by abdominal tergites VIII + IX that was used for injecting eggs into hosts and enlarged tridactylous claws supposedly for clasping hosts. Our results suggest that eremochaetids are among the earliest definite records of parasitoid insects. Our findings reveal an unexpected morphological specialization of flies and broaden our understanding of the evolution and diversity of ancient parasitoid insects.


Asunto(s)
Evolución Biológica , Dípteros/clasificación , Fósiles , Parásitos/clasificación , Ámbar , Animales , Dípteros/anatomía & histología , Parásitos/anatomía & histología
8.
Platelets ; 27(2): 123-7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26083681

RESUMEN

UNLABELLED: The aim of this article is to investigate the megakaryopoyesis and thrombopoiesis in preterm infants born to mothers with preeclampsia and the potential effects mediated by soluble fms-like tyrosine kinase 1 (sFlt1) and thrombopoietin (TPO). A perspective case-control study was performed on 26 cord blood of preterm newborns born to mothers with preeclampsia (PE group) and 26 of preterms born to mothers without preeclampsia (control group). Circulating megakaryocyte count and megakaryocyte colony forming units (CFU-MK) were quantified by whole blood infiltration method and plasma clot culture system, respectively. Platelet activation markers, CD62P and CD63, were estimated by flow cytometry. Immunosorbent assays (ELISA) were employed to estimate plasma levels of sFlt1 and TPO of the two groups. When compared to the controls, infants born to mothers with PE had significantly lower peripheral platelet count (PE vs. CONTROLS: 157.9 [44.6] vs. 239.6 [57.5] × 10(9)/l, p < 0.001), circulating MK count (5.8 [1.0] vs. 7.7 [0.9]/ml, p < 0.001) and CFU-MK (14.1 [2.1] vs. 20.1 [2.8]/1 × 10(5) cell, p < 0.001); greater expressions of CD62P (15.5 [2.3] vs. 11.4 [1.9]% platelets, p < 0.001) and CD63 (12.3 [2.4] vs. 9.0 [1.6]% platelets, p < 0.001); increased plasma Flt level (130.1 [8.0] vs. 97.7 [8.7] pg/ml, p < 0.001) and TPO level (129.5 [17.8] vs. 98.9 [11.8] pg/ml, p < 0.001). In PE group, sFlt instead of TPO showed a significantly negative relationship with platelet counts, CFU-MK and circulating MK count, a positive relationship with CD62P, CD63 expressions. In control group, both sFlt and TPO did not show any relationship with these parameters. sFlt played important role in megakaryocytopoesis and platelet homeostasis in preterm infants born to mothers with PE. Its mechanism maybe the effect of impaired megakaryocyte formation and increased platelet activation.


Asunto(s)
Plaquetas/metabolismo , Megacariocitos/metabolismo , Preeclampsia/sangre , Trombopoyesis , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre , Plaquetas/patología , Estudios de Casos y Controles , Femenino , Expresión Génica , Homeostasis , Humanos , Recién Nacido , Recien Nacido Prematuro , Megacariocitos/patología , Selectina-P/sangre , Selectina-P/genética , Activación Plaquetaria , Preeclampsia/genética , Preeclampsia/patología , Embarazo , Estudios Prospectivos , Tetraspanina 30/sangre , Tetraspanina 30/genética , Trombopoyetina/sangre , Trombopoyetina/genética , Receptor 1 de Factores de Crecimiento Endotelial Vascular/genética
9.
Artículo en Zh | MEDLINE | ID: mdl-26653651

RESUMEN

OBJECTIVE: To explore the value of color doppler ultrasound examination of thyroid in occupational health care of radiation-exposed physicians. METHODS: One hundred and thirty-four radiation-exposed physicians (observation group) and sixty-eight non-radiation-exposed physicians (control group) received color doppler ultrasound examination of thyroid using ALOKA SSD-4000 color doppler ultrasonic diagnostic apparatus, and the results were compared between the two groups. RESULTS: The anteroposterior diameters of the left lobe, right lobe, and isthmus of the thyroid in the observation group were significantly larger than those in the control group (P < 0.01). Compared with the control group, the observation group had significantly larger internal diameters and peak blood flow velocities during systole of the right superior thyroid artery (P < 0.05, P < 0.05). There were no significant differences in detection rates of thyroid nodules and lymph nodes between the observation group and the control group (18.7% vs 13.2%, P > 0.05; 6.7% vs 1.5%, P > 0.05). The radiation-exposed physicians were exposed to low-dose ionizing radiation with a dose between 0.14 and 1.67 mSv/a. CONCLUSION: The color doppler ultrasound examination of the thyroid can detect early changes in the thyroid of radiation-exposed physicians exposed to long-term and low-dose ionizing radiation.


Asunto(s)
Exposición Profesional/análisis , Salud Laboral , Médicos , Exposición a la Radiación/análisis , Glándula Tiroides/diagnóstico por imagen , Ultrasonografía Doppler en Color , Humanos , Ganglios Linfáticos , Radiación Ionizante , Glándula Tiroides/efectos de la radiación
10.
Pediatr Surg Int ; 30(1): 47-53, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24258515

RESUMEN

PURPOSE: To describe the prenatal findings, treatments and outcomes of fetuses with pulmonary sequestrations (PS), which were retrospectively studied. METHODS: From May 2010 to January 2013, 292 women were referred to the Guangdong Women and Children Hospital, Guangzhou because obstetric ultrasound had demonstrated fetal lung lesions. In 68 fetuses, the echogenic lung masses were pulmonary sequestrations deriving arterial blood supply from clearly identifiable systemic arteries rather than the pulmonary artery. We examined records of the 68 fetuses and measured the lesions and congenital cystic adenomatoid malformation volume ratio (CVR), provided prenatal counseling and treatment, documented the CVR, location of lesion, gestational age at diagnosis, need for fetal intervention, perinatal clinical course (including the development of hydrops, effusions, and neonatal respiratory distress), gestational age at delivery, postnatal ultrasound and CT, operation treatment, survival and pathology. RESULTS: There were 68 PS in our study. All of 56 cases with CVR ≤ 1.6, survived without prenatal hydrops or postnatal respiratory symptoms. In 12 cases with CVR >1.6, 7 cases (58.3 %, 7/12) had hydrops, 10 cases (83.3 %, 10/12) survived, 2 cases (16.7 %, 2/12) of induced abortion, 8 cases (66 %, 8/12) were postnatal symptomatic. There was statistical significant difference in the incidence rate of hydrops and postnatal respiratory symptoms between the PS with CVR ≤ 1.6 and that with CVR >1.6. 66 cases postnatal survived, two cases of induced abortion. 64 cases had no prenatal treatment, two cases underwent thoracoamniotic shunt. The mean gestational age at birth was 38 weeks (range 34-40 weeks). 21 asymptomatic cases had no surgery. 45 cases (8 symptomatic and 37 asymptomatic) underwent surgical resections, 43 cases without postoperative complications, two cases of postoperative pneumothorax, no wound infection. Postoperative follow-up showed good growth in all surgery cases. CONCLUSION: PS specific absence of hydrop was a congenital disorder with an excellent prognosis. CVR >1.6 was associated with fetal hydrops and postnatal symptoms. However, absolute CVR value cannot be used to select fetuses for fetal treatment before the development of hydrops. Surgery of PS in neonates or infants presented a good outcome.


Asunto(s)
Secuestro Broncopulmonar/diagnóstico por imagen , Secuestro Broncopulmonar/cirugía , Enfermedades Fetales/diagnóstico por imagen , Atención Prenatal/métodos , Ultrasonografía Prenatal/métodos , Aborto Inducido , Secuestro Broncopulmonar/complicaciones , China , Malformación Adenomatoide Quística Congénita del Pulmón/complicaciones , Malformación Adenomatoide Quística Congénita del Pulmón/diagnóstico , Femenino , Estudios de Seguimiento , Humanos , Hidropesía Fetal/diagnóstico , Recién Nacido , Pulmón/diagnóstico por imagen , Masculino , Embarazo , Estudios Retrospectivos , Resultado del Tratamiento
11.
Zootaxa ; 3764: 581-6, 2014 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-24870657

RESUMEN

Tianyuprosbole zhengi, a remarkable new genus and species of Tettigarctidae (Insecta, Hemiptera, Cicadoidea), is described based on a whole-bodied fossil from the Middle Jurassic of Daohugou, northeastern China. The new species possesses a tegmen similar to that of Cicadoprosbole, the type genus of Cicadoprosbolinae, and has an exceedingly expanded pronotum as the extant genus Tettigarcta. This specimen provides new insights in the evolution and taxonomy of tettigarctids.


Asunto(s)
Hemípteros/clasificación , Animales , China , Fósiles , Hemípteros/anatomía & histología
12.
J Cardiothorac Surg ; 19(1): 49, 2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-38310253

RESUMEN

BACKGROUND: Right-sided infective endocarditis (RSIE) is a relatively uncommon condition which is difficult to distinguish from thrombus, particularly when the site of infection or the patient's symptoms are atypical. There have been few reports exploring the differential diagnostic and analytical features between RSIE and thrombus. CASE PRESENTATION: Here, we presented two cases of RSIE-one involving the tricuspid valve and the other affecting the pulmonary artery. Notably, the second case was initially misdiagnosed as thrombus based on the findings of by computed tomography angiography(CTA). CONCLUSIONS: Vegetation and thrombus can be distinguished according to the nature of the mass, its attachment location, and the clinical manifestation. Echocardiography can observe both the location and size of the mass, and the dynamic changes in cardiac hemodynamics and cardiac morphology, thereby facilitating an effective distinction between vegetation and thrombus.


Asunto(s)
Endocarditis Bacteriana , Endocarditis , Trombosis , Humanos , Endocarditis/diagnóstico por imagen , Ecocardiografía , Válvula Tricúspide/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Trombosis/diagnóstico por imagen , Endocarditis Bacteriana/diagnóstico por imagen
13.
Nat Commun ; 15(1): 376, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38191461

RESUMEN

Extant cicada (Hemiptera: Cicadoidea) includes widely distributed Cicadidae and relictual Tettigarctidae, with fossils ascribed to these two groups based on several distinct, minimally varying morphological differences that define their extant counterparts. However, directly assigning Mesozoic fossils to modern taxa may overlook the role of unique and transitional features provided by fossils in tracking their early evolutionary paths. Here, based on adult and nymphal fossils from mid-Cretaceous Kachin amber of Myanmar, we explore the phylogenetic relationships and morphological disparities of fossil and extant cicadoids. Our results suggest that Cicadidae and Tettigarctidae might have diverged at or by the Middle Jurassic, with morphological evolution possibly shaped by host plant changes. The discovery of tymbal structures and anatomical analysis of adult fossils indicate that mid-Cretaceous cicadas were silent as modern Tettigarctidae or could have produced faint tymbal-related sounds. The discovery of final-instar nymphal and exuviae cicadoid fossils with fossorial forelegs and piercing-sucking mouthparts indicates that they had most likely adopted a subterranean lifestyle by the mid-Cretaceous, occupying the ecological niche of underground feeding on root. Our study traces the morphological, behavioral, and ecological evolution of Cicadoidea from the Mesozoic, emphasizing their adaptive traits and interactions with their living environments.


Asunto(s)
Hemípteros , Animales , Filogenia , Ámbar , Ecosistema , Miembro Anterior , Ninfa
14.
Zootaxa ; 3736: 387-91, 2013 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-25112637

RESUMEN

A new genus and new species of Saucrosmylinae (Insecta, Neuroptera) is described as Huiyingosmylus bellus gen. et sp. nov., based on a well-preserved forewing from the Middle Jurassic of Daohugou, Inner Mongolia, China. Huiyingosmylus gen. nov. is characterized by the large size of forewing, relatively wide R1 space with several rows of cells, anteriorly bent Rs, dense crossveins over the entire wing and undulate outer margin. A key to the genera of Saucrosymylinae is provided.


Asunto(s)
Insectos/clasificación , Animales , China , Ecosistema , Fósiles , Insectos/anatomía & histología , Alas de Animales/anatomía & histología
15.
Anat Rec (Hoboken) ; 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36641784

RESUMEN

A new Middle Triassic (Ladinian) planthopper of the family Surijokocixiidae (Surijokocixioidea, Fulgoromorpha) from the Tongchuan Formation in Shaanxi, NW China is established as Sinosurijikocixius tongchuanensis gen. et sp. nov. All the known taxa assigned to Surijokocixiidae are reviewed and compared. The palaeogeographic distributional pattern of Surijokocixiidae from the middle Permian to Late Triassic is summarized.

16.
Anat Rec (Hoboken) ; 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37161734

RESUMEN

A complete and well-preserved forewing assigned to the orthopteran insect Parahagla cheni Xu, Fang and Zhang, 2023 is described from the Lower Jurassic Badaowan Formation of the northwestern Junggar Basin (Karamay, Xinjiang, northwestern China), based on which the species is diagnostically revised. It represents the earliest record of the subfamily Chifengiinae under the family Prophalangopsidae. The subfamily Chifengiinae is reviewed and a key to its genera and species is provided in the discussion. A further discuss of the palaeobiogeographic distribution of Chifengiinae shows that the subfamily probably first appeared in the Palaeoarctic in the earliest Jurassic, and later quickly migrated and occupied most areas of eastern Palaeoarctic from the Middle Jurassic to the Early Cretaceous.

17.
Geobiology ; 20(3): 363-376, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35212124

RESUMEN

Fossilized tree resin, or amber, commonly contains fossils of animals, plants and microorganisms. These inclusions have generally been interpreted as hollow moulds or mummified remains coated or filled with carbonaceous material. Here, we provide the first report of calcified and silicified insects in amber from the mid-Cretaceous Kachin (Burmese) amber. Data from light microscopy, scanning electron microscopy (SEM), energy-dispersive and wavelength-dispersive X-ray spectroscopy (EDX and WDX), X-ray micro-computed tomography (Micro-CT) and Raman spectroscopy show that these Kachin fossils owe their preservation to multiple diagenetic mineralization processes. The labile tissues (e.g. eyes, wings and trachea) mainly consist of calcite, chalcedony and quartz with minor amounts of carbonaceous material, pyrite, iron oxide and phyllosilicate minerals. Calcite, quartz and chalcedony also occur in cracks as void-filling cements, indicating that the minerals formed from chemical species that entered the fossil inclusions through cracks in the resin. The results demonstrate that resin and amber are not always closed systems. Fluids (e.g. sediment pore water, diagenetic fluid and ground water) at different burial stages have chances to interact with amber throughout its geological history and affect the preservational quality and morphological fidelity of its fossil inclusions.


Asunto(s)
Ámbar , Cuarzo , Ámbar/química , Animales , Carbonato de Calcio , Fósiles , Insectos , Microtomografía por Rayos X
18.
Micromachines (Basel) ; 12(7)2021 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-34202062

RESUMEN

NAND flash memory is widely used in communications, commercial servers, and cloud storage devices with a series of advantages such as high density, low cost, high speed, anti-magnetic, and anti-vibration. However, the reliability is increasingly getting worse while process improvements and technological advancements have brought higher storage densities to NAND flash memory. The degradation of reliability not only reduces the lifetime of the NAND flash memory but also causes the devices to be replaced prematurely based on the nominal value far below the minimum actual value, resulting in a great waste of lifetime. Using machine learning algorithms to accurately predict endurance levels can optimize wear-leveling strategies and warn bad memory blocks, which is of great significance for effectively extending the lifetime of NAND flash memory devices and avoiding serious losses caused by sudden failures. In this work, a multi-class endurance prediction scheme based on the SVM algorithm is proposed, which can predict the remaining P-E cycle level and the raw bit error level after various P-E cycles. Feature analysis based on endurance data is used to determine the basic elements of the model. Based on the error features, we present a variety of targeted optimization strategies, such as extracting the numerical features closely related to the endurance, and reducing the noise interference of transient faults through short-term repeated operations. Besides a high-parallel flash test platform supporting multiple protocols, a feature preprocessing module is constructed based on the ZYNQ-7030 chip. The pipelined module of SVM decision model can complete a single prediction within 37 us.

19.
Sci Adv ; 7(18)2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33931457

RESUMEN

During the Mid-Miocene Climatic Optimum [MMCO, ~14 to 17 million years (Ma) ago], global temperatures were similar to predicted temperatures for the coming century. Limited megathermal paleoclimatic and fossil data are known from this period, despite its potential as an analog for future climate conditions. Here, we report a rich middle Miocene rainforest biome, the Zhangpu biota (~14.7 Ma ago), based on material preserved in amber and associated sedimentary rocks from southeastern China. The record shows that the mid-Miocene rainforest reached at least 24.2°N and was more widespread than previously estimated. Our results not only highlight the role of tropical rainforests acting as evolutionary museums for biodiversity at the generic level but also suggest that the MMCO probably strongly shaped the East Asian biota via the northern expansion of the megathermal rainforest biome. The Zhangpu biota provides an ideal snapshot for biodiversity redistribution during global warming.

20.
Ultrasonography ; 39(4): 356-366, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32407611

RESUMEN

PURPOSE: The purpose of this study was to retrospectively compare the clinical characteristics and imaging features on (CEUS) of combined hepatocellular cholangiocarcinoma (CHC) with those of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). METHODS: The clinical information and CEUS features of 45 patients with CHC from 2015 to 2019 and 1-to-1-matched control subjects with HCC and CC (45 each) were compared. RESULTS: Simultaneous elevation of α-fetoprotein (AFP) and cancer antigen (CA) 19-9 was more common in CHC than in HCC and CC. In the arterial phase, hyperenhancement (homogeneous and heterogeneous) was more common in CHC (73.3%) and HCC (100%), while peripheral rimlike enhancement was more common in CC (55.6%). In the portal phase, marked washout was significantly more frequent in CHC and CC than in HCC (42.2% and 53.3% vs. 6.7%). In the delayed phase, marked washout was more common in CHC (82.2%) and CC (93.3%) than in HCC (40.0%). The washout time (WT) was much shorter in CHC and CC than in HCC (33.8±13.1 seconds and 30.1±11.6 seconds vs. 58.4±23.5 seconds). Using the combination of simultaneous elevation of AFP and CA 19-9 with marked washout in the delayed phase and a WT <38 seconds or arterial hyperenhancement to differentiate CHC from HCC or CC, the accuracy, sensitivity, and specificity were 74.4%, 93.3%, and 55.6% and 71.1%, 80.0%, and 62.2%, respectively. CONCLUSION: Although some CEUS imaging features of CHC, HCC, and CC overlap, the combination of tumor markers and CEUS features can be helpful in differentiating CHC from HCC and CC.

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