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Mimicking nature at multiple scales

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Nano Research 2022年第7期15卷 6447-6448页

作者： Helmut cölfen Physical chemistry Department of ChemistryUniversity of KonstanzUniversitätsstraße 10Box 714D-78457 KonstanzGermany

Nacre-like ceramics have received an intense focus from the structural material community because the inherently low damage resistance of ceramics,which is a fatal deficiency of ceramics as reliable load-bearing *** can be improved through nacreinspired structural designs,i.e.,the“brick-and-mortar”structure with alternating soft and hard layers on the *** technologies have been developed to produce nacre-like ceramics,including freeze casting[1],magnetically assisted slip casting[2],laminating[3]and biomimetic mineralization[4].The obtained artificial ceramics can exhibit extraordinary anti-fracture behavior without introducing a high volume fraction of ductile nonceramic components causing a drastic strength decrease of the ***.

关键词： ceramics material. ceramic

clinical management of infertile men with nonobstructive azoospermia

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Asian Journal of Andrology 2015年第3期17卷 459-470页

作者： Sandro c Esteves ANDROFERT Center for Male Reproduction Campinas 13075-460 Brazil

The clinical management of men with nonobstructive azoospermia （NOA） seeking fertility has been a challenge for andrologists, urologists, and reproductive medicine specialists alike. This review presents a personal perspective on the clinical management of NOA, including the lessons learned over 15 years dealing with this male infertility condition. A five-consecutive-step algorithm is proposed to manage such patients. First, a differential diagnosis of azoospermia is made to confirm/establish that NOA is due to spermatogenic failure. Second, genetic testing is carried out not only to detect the males in whom NOA is caused by microdeletions of the long arm of the Y chromosome, but also to counsel the affected patients about their chances of having success in sperm retrieval. Third, it is determined whether any intervention prior to a surgical retrieval attempt may be used to increase sperm production. Fourth, the most effective and efficient retrieval method is selected to search for testicular sperm. Lastly, state-of-art laboratory techniques are applied in the handling of retrieved gametes and cultivating the embryos resulting from sperm injections. A coordinated multidisciplinary effort is key to offer the best possible chance of achieving a biological offspring to males with NOA.

关键词： intracytoplasmic sperm injection male infertility nonobstructive azoospermia pregnancy outcome sperm retrieval spermatogenic failure

Modeling Impacts on Space Situational Awareness PHD Filter Tracking

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computer Modeling in Engineering & Sciences 2016年第2期111卷 171-201页

作者： c.Frueh Purdue University West-LafayetteINUSA.

In recent years,probabilistic tracking methods have been becoming increasingly popular for solving the multi-target tracking problem in Space Situational Awareness(SSA).Bayesian frameworks have been used to describe the objects’of interest states and cardinality as point *** inputs of the Bayesian framework filters are a probabilistic description of the scene at hand,the probability of clutter during the observation,the probability of detection of the objects,the probability of object survival and birth rates,and in the state update,the measurement uncertainty and process noise for the ***,in the filter derivation,the assumptions of Poisson distributions of the object prior and the clutter model are *** the first-order moments of the full Bayesian framework leads to a so-called Probability Hypothesis Density(PHD)*** first moment extraction of the PHD filter process is extremely sensitive to both the input parameters and the *** specifics of the SSA problem and its probabilistic description are illustrated in this paper and compared to the assumptions that the PHD filter is based *** an example,this paper shows the response of a cardinality only PHD filter(only the number of objects is estimated,not their corresponding states)to different input *** very simple cardinality only PHD filter is chosen in order to clearly show the sole effects of the model mismatch that might be blurred with state estimation effects,such as non-linearity in the dynamical model,in a full PHD filter *** simulated multi-target tracking scenario entails the observation of attitude stable and unstable geostationary objects.

关键词： Space Situational Awareness Space Debris Finite set statistics Tracking Modeling

Diagnosis and management of angioedema with abdominal involvement:A gastroenterology perspective

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World Journal of Gastroenterology 2010年第39期16卷 4913-4921页

作者： Ugochukwu c Nzeako Gastroenterology HepatologyGastrointestinal EndoscopyWatson Clinic LLP

Abdominal involvement in angioedema is often a challenge to *** onset abdominal pain is its most common presenting symptom,and misdiagnosis may lead to unnecessary surgical *** with the types and presentations of angioedema can be invaluable to clinicians as they consider the differential diagnoses of a patient presenting with abdominal pain. Detailed personal and family histories,careful physical examination of the patient,combined with knowledge of angioedema types,can help clinicians perform their diagnostic *** accurate diagnosis is essential in order to provide appropriate treatment to patients with *** upon the diagnosis,treatment may be the avoidance of provoking factors(such as allergens or medications),inhibiting histamine-provoked reactions,or treating c1 esterase inhibitor deficiency.

关键词： Acquired angioedema Angiotensin-converting enzyme-induced angioedema Gastrointestinal Hereditary angioedema c1 esterase inhibitor deficiency

A classification of induced seismicity

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Geoscience Frontiers 2018年第6期9卷 1903-1909页

作者： c.Doglioni Dipartimento Scienze della Terra UniversitàSapienza di RomaItaly Istituto Nazionale di Geofisica e Vulcanologia RomaItaly

In order to adopt the best safety procedures, man-made earthquakes should be differentiated as a function of their origin. At least four different types of settings can be recognized in which anthropogenic activities may generate seismicity:(I) fluid removal from a stratigraphic reservoir in the underground can trigger the compaction of the voids and the collapse of the overlying volume, i.e., graviquakes; the deeper the reservoir, the bigger the volume and the earthquake magnitude;(II) wastewater or gas reinjection provides the reduction of friction in volumes and along fault planes, allowing creep or sudden activation of tectonic discontinuities, i.e., reinjection quakes;(III) fluid injection at supra-lithostatic pressure generates hydrofracturing and micro-seismicity, i.e., hydrofracturing quakes;(IV) fluid extraction or fluid injection,filling or unfilling of artificial lakes modifies the lithostatic load, which is the maximum principal stress in extensional tectonic settings, the minimum principal stress in contractional tectonic settings, and the intermediate principal stress in strike-slip settings, i.e., load quakes; over given pressure values, the increase of the lithostatic load may favour the activation of normal faults, whereas its decrease may favour thrust faults. For example, the filling of an artificial lake may generate normal fault-related ***, each setting has its peculiarities and the knowledge of the different mechanisms may contribute to the adoption of the appropriate precautions in the various industrial activities.

关键词： Anthropogenic seismicity Graviquakes Reinjection quakes Hydrofracturing quakes Load quakes

Etiology and evaluation of diarrhea in AIDS:a global perspective at the millennium

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World Journal of Gastroenterology 2000年第2期6卷 177-186页

作者： c.MelWilcox Department of Medicine Division of Gastroenterology and HepatologyCenter for AIDS ResearchUniversity of Alabama at BirminghamBirminghamAlabama

INTRODUcTIONIt has now been almost 20 years since the initialdescriptions of a heretofore unrecognized disorderafflicting homosexual men and manifesting asPneumocystis carinii pneumonia and Kaposi’*** the identification of the humanimmunodeficiency virus(HIV) as the etiology ofthis syndrome,there has been exponential growth inour understanding of this devastating

关键词： acquired immunodeficiency syndrome/etiology acquired immunodeficiency syndrome/complications diarrhea HIV immunocompetense endoscopy

REVIEW OF PARTIcLE PHYSIcS Particle Data Group

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chinese Physics c 2016年第10期40卷 1-28页

作者： c. Patrignani (Particle Data Group) Chinese Physics C 40 100001 (2016)

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,062 new measurements from 721 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, cosmology, Particle Detectors, colliders, Probability and Statistics. Among the 117 reviews are many that are new or heavily revised, including new reviews on Pentaquarks and Inflation. The complete Review is published online in a journal and on the website of the Particle Data Group （http：//pdg. lbl. gov）. The printed PDG Book contains the Summary Tables and all review articles but no longer includes the detailed tables from the Particle Listings. A Booklet with the Summary Tables and abbreviated versions of some of the review articles is also available.

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Baryon structure from Lattice QcD

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chinese Physics c 2009年第12期33卷 1093-1101页

作者： c. Alexandrou Department of Physics University of Cyprus P.O. Box 20357 Nicosia CY-1678 Cyprus computation-based Science and Technology Research center Cyprus Institute 20 Kavafi Street Nicosia 2121 Cyprus

We present recent lattice results on the baryon spectrum, nucleon electromagnetic and axial form factors, nucleon to △ transition form factors as well as the △ electromagnetic form factors. The masses of the low lying baryons and the nucleon form factors are calculated using two degenerate flavors of twisted mass fermions down to pion mass of about 270 MeV. We compare to the results of other collaborations. The nucleon to △ transition and △ form factors are calculated in a hybrid scheme, which uses staggered sea quarks and domain wall valence quarks. The dominant magnetic dipole nucleon to △ transition form factor is also evaluated using dynamical domain wall fermions. The momentum frame are extracted using the form factors transverse density distributions of the △ in the infinite determined from lattice QcD.

关键词： lattice QcD hadron spectrum nucleon form factors △ form factors and density distributions

A mechanistic study of cO removal on a small H-saturated platinum cluster

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Science china chemistry 2008年第12期51卷 1187-1196页

作者： FORREY Robert c Department of Physics Pennsylvania State University Berks Campus Reading PA 19610 USA

cO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applications. Using density functional theory (DFT), we performed systematic theoretical calcula-tions to explore the cO removal mechanisms, in the presence of hydrogen, via oxidation by oxygen to form cO2 or reduction by hydrogen to form formaldehyde using a subnano Pt cluster as a model for catalyst nanoparticles. We show that cO oxidation is both thermochemically and kinetically difficult at low H coverage but becomes very exothermic with a moderate activation barrier at high H coverage, suggesting that the oxidation can be carried out readily at elevated temperatures. Doping the Pt cluster with Ru can significantly improve the oxidation thermochemical energy and moderately reduce the activation barrier. The results are consistent with experimental observations. We found that cO reduction by hydrogen to form formaldehyde is moderately endothermic. However, the reaction is predicted to be kinetically difficult due to the relatively high activation barriers associated with the sequential H attacks to the cO molecule.

关键词： cluster Pt-Au alloy full H-saturation cO oxidation cO hydrogenation density functional theory