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Medical therapy for spermatogenic failure

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Asian j.urnal of Andrology 2012年第1期14卷 57-60,176页

作者： Ranj.th Ramasamy peter j.Stahl peter N Schlegel Department of Urology Weill Cornell Medical College New York NY 10065 USA

Medical treatment of men with primary spermatogenic failure remains largely ineffective in contrast to those with secondary testicular failure. Treatment has been attempted with a multitude of agents ranging from hormones to nutritional supplements （antioxidants）. While some studies have demonstrated benefit to some treatments, no treatments have consistently demonstrated efficacy nor has it been possible to reliably identify patients likely to benefit. Idiopathic spermatogenic failure likely results from multiple discrete defects in sperm production that are as yet unidentified. A better understanding of these defects will yield more effective treatment options and appropriate triage of patients to specific therapeutic regimens. This review focuses on the rationale and current evidence for hormonal and antioxidant therapy in medical treatment of male infertility, spermatogenic failure in particular. Although empiric medical therapy for spermatogenic failure has been largely replaced by assisted reproductive techniques, both treatment modalities could play a role, oerhaos as combination therapy.

关键词： antioxidant hormones male infertility sperm spermatogenesis spermatogenic failure testicular failure

On the Applications of the Linear Recurrence Relationships to Pseudoprimes

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j.urnal of Mathematical Research with Applications 2019年第6期39卷 563-574页

作者： Tianxiao HE peter j.-S.SHIUE Department of Mathematics Illinois Wesleyan University Department of Mathematical Sciences University of Nevada Las Vegas

We present here some results on the applications of linear recursive sequences of order 2 to the Fermat pseudoprimes, Fibonacci pseudoprimes, and Dickson pseudoprimes.

关键词： Girard-Waring identities Recursive sequences Fermat’s pseudoprimes Fibonacci numbers Lucas numbers Fibonacci pseudoprimes Dickson numbers Dickson pseudoprimes

New technologies in the gastrointestinal clinic and research: Impedance and high-resolution manometry

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World j.urnal of Gastroenterology 2009年第2期15卷 131-138页

作者： j.hn E Pandolfino peter j.Kahrilas Division of Gastroenterology Department of Medicine Northwestern University Feinberg School of Medicine Suite 1400 Chicago Illinois 60611 United States

The last five years have been an exciting time in the study of esophageal motor disorders due to the recent advances in esophageal function testing. New technologies have emerged, such as intraluminal impedance, while conventional techniques, such as manometry, have enj.yed many improvements due to advances in transducer technology, computerization and graphic data presentation. While these techniques provide more detailed information regarding esophageal function, our understanding of whether they can improve our ability to diagnose and treat patients more effectively is evolving. These techniques are also excellent research tools and they have added substantially to our understanding of esophageal motor function in dysphagia. This review describes the potential benefits that these new technologies may have over conventional techniques for the evaluation of dysphagia.

关键词： Dysphagia, Multichannel intraluminal Impedance Bolus transit High-resolution manometry Esophagogastric j.nction Achalasia

Making the link between ADF and 4D STEM:Resolution,transfer and coherence

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Chinese Physics B 2024年第11期33卷 26-33页

作者： peter D.Nellist Timothy j.Pennycook Department of Materials University of OxfordOxfordUK EMAT University of AntwerpGroenenborgerlaan 1712020 AntwerpBelgium

Steve Pennycook is a pioneer in the application of high-resolution scanning transmission electron microscopy(STEM)and in particular the use of annular dark-field(ADF)*** we show how a general framework for 4D STEM allows clear links to be made between ADF imaging and the emerging methods for reconstructing images from 4D STEM data *** show that both ADF imaging and ptychographical reconstruction can be thought of in terms of integrating over the overlap regions of diffracted discs in the detector *** approach allows the similarities in parts of their transfer functions to be understood,though we note that the transfer functions for ptychographic imaging cannot be used as a measure of information *** also show that conditions of partial spatial and temporal coherence affect ADF imaging and ptychography similarly,showing that achromatic interference can always contribute to the image in both cases,leading to a robustness to partial temporal coherence that has enabled high-resolution imaging.

关键词： image forming and processing phase retrieval electron microscopy scanning transmission electron microscope(STEM)

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Endoscopic ultrasonography guided celiac plexus neurolysis and celiac plexus block in the management of pain due to pancreatic cancer and chronic pancreatitis

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World j.urnal of Gastroenterology 2007年第26期13卷 3575-3580页

作者： Anthony j.Michaels peter V Draganov University of Florida Department of GastroenterologyHepatology and NutritionUnited States

Pain is a common symptom of pancreatic disease and is frequently difficult to manage. Pain relief provided by narcotics is often suboptimal and is associated with significant side effects. An alternative approach to pain management in pancreatic disease is the use of celiac plexus block (CPB) or neurolysis (CPN). Originally performed by anesthesiologists and radiologists via a posterior approach,recent advances in endoscopic ultrasonography (EUS) have made this technique an attractive alternative. EUS guided celiac plexus block/ neurolysis is simple to perform and avoids serious complications such as paraplegia or pneumothorax that are associated with the posterior approach. EUS guided CPN should be considered first line therapy in patients with pain due to pancreatic cancer. It provides superior pain control compared to traditional management with narcotics. A trend for improved survival in pancreatic cancer patients treated with CPN has been reported,but larger studies are needed to confirm this finding. At this time,the use of EUS guided CPB cannot be recommended as routine therapy for pain in chronic pancreatitis since only one-half of the patients experience pain reduction and the beneficial effect tends to be short lived. EUS guided CPB and CPN should be used as part of a multidisciplinary team approach for pain management.

关键词： Celiac plexus Celiac plexus neurolysis Celiacplexus block Endoscopic ultrasound Pain management

Colonoscopic polypectomy and associated techniques

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World j.urnal of Gastroenterology 2010年第29期16卷 3630-3637页

作者： Christopher j.Fyock peter V Draganov Division of Gastroenterology Hepatology and NutritionUniversity of Florida

Polypectomy of colonic polyps has been shown to reduce the risk of colon cancer development and is considered a fundamental skill for all endoscopists who perform colonoscopy.A variety of polypectomy techniques and devices are available,and their use can vary greatly based on local availability and *** general,cold forceps and cold snare have been the polypectomy methods of choice for smaller polyps,and hot snare has been the method of choice for larger *** use of hot forceps has mostly fallen out of *** for difficult to remove polyps may require the use of special devices and advanced techniques and has continued to *** a result,the vast maj.rity of polyps today can be removed *** electrocautery is frequently used for polypectomy,endoscopists should be thoroughly familiar with the basic principles of electrosurgery as it pertains to *** of a polypectomy site is an important adj.nct to polypectomy and can greatly facilitate future surgery or endoscopic *** two most common post-polypectomy complications are bleeding and *** incidence can be decreased with the use of meticulous polypectomy techniques and the application of some prophylactic *** review will examine the technique of polypectomy and its complications from the perspective of the practicing gastroenterologist.

关键词： Colonic polyp Polypectomy Colonoscopy Polypectomy technique Complications

Those amazing dinoflagellate chromosomes

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Cell Research 2003年第4期13卷 215-217页

作者： peter j.RIZZO Department of Biology Texas A & M University College Station TX 77843 USA

Dinoflagellates are a very large and diverse group of eukaryotic algae that play a maj.r role in aquatic food webs of both fresh water and marine habitats. Moreover, the toxic members of this group pose a health threat in the form of red tides. Finally, dinoflagellates are of great evolutionary importance, because of their taxonomic position, and their unusual chromosome structure and composition. While the cytoplasm of dinoflagellates is typically eukaryotic, the nucleus is unique when compared to the nucleus of other eukaryotes. More specifically, while the chromosomes of all other eukaryotes contain histones, dinoflagellate chromosomes lack histones completely. There are no known exceptions to this observation: all dinoflagellates lack histones, and all other eukaryotes contain histones. Nevertheless, dinoflagellates remain a relatively unstudied group of eukaryotes.

关键词： dinofiagellates chromosomes histones histone-like proteins.

Participation of CD45,NKR-P1A and ANK61 antigen in rat hepatic NK cell(pit cell)-mediated target cell cytotoxicity

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World j.urnal of Gastroenterology 2000年第4期6卷 546-552页

作者： David Vermiilen Bülent Ahishali Vasilis Triantis Karin Vanderkerken peter j. K.Kuppen Eddie Wisse Laboratory for Cell Biology and Histology. Department of Hematology and immunology Free University of Brussels(VUB)Brussels-JetteBelgium K Vanderkerken is a postdoctoral researcher of the Fund for Scientific Research Flanders. Department of Surgery and Pathology Leiden University Medical CenterLeidenThe Netherlands

AIM Several triggering receptors have beendescribed to be involved in natural killer（NK）cell-mediated target *** these studies,NKcells derived from blood or spleen were *** are liver-specific NK cells that possess ahigher level of natural cytotoxicity and a differentmorphology when compared to blood NK *** aim of this study was to characterize the roleof the NK-triggering molecules NKR-P1A,ANK61antigen,and CD45 in pit cell-mediated killing oftarget *** 51Cr-release and DNA fragmentationwere used to quantify target cell lysis andapoptosis,*** Flow cytometric analysis showed thatpit cells expressed CD45,NKR-P1A,and *** of pit cells with monoclonalantibody（mAb）to CD45（ANK74）not onlyinhibited CC531s or YAC-1 target lysis but alsoapoptosis induced by pit *** mAbs to NKR-P1A（3.2.3）and ANK61 antigen（ANK61）had no effect on pit cell-mediated CC531s or YAC-1 targetcytolysis or apoptosis,while they did increase theFcγ receptor positive（FcγR+）P815 cytolysis *** enhanced cytotoxicity could beinhibited by 3,4-dichloroisocoumarin,an inhibitorof *** These results indicate that CD45participates in pit cell-mediated CC531s and YAC-1target cytolysis and ***-P1A andANK61 antigen on pit cells function as activationstructures against FcγR+ P815 cells,which wasmediated by the perforin/granzyme pathway.

关键词： hepatic NK cells pit cells cytolysis apoptosis perforin/granzyme pathway

Dissolved organic matter tracers reveal contrasting characteristics across high arsenic aquifers in Cambodia:A fluorescence spectroscopy study

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Geoscience Frontiers 2019年第5期10卷 1653-1667页

作者： Laura A. Richards Dan j. Lapworth Daniel Magnone Daren C. Gooddy Lee Chambers peter j. Williams Bart E. van Dongen David A. Polya School of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science The University of ManchesterWilliamson BuildingOxford RoadManchesterM13 9PLUK British Geological Survey Maclean BuildingWallingfordOxfordshireOX10 8BBUK Lancaster Environment Centre Lancaster UniversityLancaster LA1 4YQUK Present address: School of Geography University of LincolnBrayford PoolLincolnLincolnshireLN6 7 TSUK Present address: Department of Civil and Environmental Engineering University of StrathclydeGlasgow G1 1XJUK

Organic matter in the environment is involved in many biogeochemical processes,including the mobilization of geogenic trace elements,such as arsenic,into *** this paper we present the use of fluorescence spectroscopy to characterize the dissolved organic matter (DOM) pool in heavily arsenicaffected groundwaters in Kandal Province,*** fluorescence DOM (fDOM) characteristics between contrasting field areas of differing dominant lithologies were compared and linked to other hydrogeochemical parameters,including arsenic and dissolved methane as well as selected sedimentary ***-corrected fluorescence indices were used to characterize depth profiles and compare field *** fDOM was generally dominated by terrestrial humic and fulvic-like components,with relatively small contributions from microbially-derived,tryptophan-like *** fDOM from sand-dominated sequences typically contained lower tryptophan-like,lower fulvic-like and lower humic-like components,was less bioavailable,and had higher humification index than clay-dominated *** concentrations were strongly correlated with fDOM bioavailability as well as with tryptophan-like components,suggesting that groundwater methane in these arsenic-prone aquifers is likely of biogenic origin.A comparison of fDOM tracers with sedimentary OM tracers is consistent with the hypothesis that external,surface-derived contributions to the aqueous DOM pool are an important control on groundwater hydrogeochemistry.

关键词： Arsenic Fluorescence spectroscopy Organic matter characterization Parallel factor analysis (PARAFAC) Groundwater quality

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