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Medical therapy for spermatogenic failure

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Asian journal of Andrology 2012年第1期14卷 57-60,176页

作者： Ranjith 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

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

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World journal of Gastroenterology 2009年第2期15卷 131-138页

作者： john 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 enjoyed 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 junction Achalasia

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 journal 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 journal 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 majority 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 adjunct 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 major 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.

Protective and Regenerative Efficacy of a Plant Oil-Based Day and Night Cream: Investigated by a Novel Approach to Reveal the Impact of Blue Light Irradiation on Epidermal Barrier Integrity and Lipid Matrix

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journal of Cosmetics, Dermatological Sciences and Applications 2024年第3期14卷 227-241页

作者： Dorothee Dähnhardt Stephan Dähnhardt-Pfeiffer Isabel Simon Dana Ditgen Inge Holland Dörte Segger peter Staib Microscopy Services Dhnhardt GmbH Flintbek Germany Research & Development and Regulatory Affairs Kneipp GmbH Wuerzburg Germany SGS INSTITUT FRESENIUS GmbH Hamburg Germany

In recent years, the harmful effects of blue light (400 - 500 nm) as a component of visible light (400 - 700 nm) have increasingly gained attention of science, industry, and consumers. To date, only a few in vivo test methods for measuring the effects of blue light on the skin have been described. A direct measurement method that can detect the immediate effects of blue light on the epidermal permeability barrier (EPB) is still lacking. In this study, we present a new methodological approach that can be used to investigate both the protective and regenerative effects of cosmetic products on the EPB after blue light irradiation. In a study with 14 female volunteers, it was investigated whether the regular application of an O/W emulsion (day cream) can strengthen and protect the epidermal barrier against damaging blue light radiation of 60 j/cm2 (protective study design) and also whether a disruption of the epidermal barrier caused by blue light radiation is restored faster and better by the regular application of another O/W emulsion (night cream) than in product-untreated skin (regenerative study design). The two O/W emulsions are different in plant oil, active ingredient composition and texture. The seven-day treatment with the day cream initially led to a significant increase in the normalized lipid lamellae length in the intercellular space, whereas the irradiation with blue light after 24 hours led to a significant decrease in the lipid lamellae length in the untreated test area, but not in the area previously treated with the product. Regarding the regenerative study design, a two-day treatment with the night cream was able to restore a blue-light-induced decrease in lipid lamellae length in the intercellular space. In summary, with the study designs presented here, the protective and regenerative effect of two cosmetic products could be demonstrated for the first time on the integrity of the EPB after blue light irradiation and the data showed that the Lipbarv

关键词： Skin Care Blue Light Irradiation Skin Barrier Intercellular Lipid Lamellae Electron Microscopy

Phase Transitions for Products of Characteristic Polynomials under Dyson Brownian Motion

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Acta Mathematica Sinica,English Series 2021年第3期37卷 509-524页

作者： peter j.FORRESTER Dang-Zheng LIU ARC Centre of Excellence for Mathematical and Statistical Frontiers School of Mathematics and StatisticsThe University of MelbourneVictoria 3010Australia CAS Key Laboratory of Wu Wen-Tsun Mathematics School of Mathematical SciencesUniversity of Science and Technology of ChinaHefei 230026P.R.China

We study the averaged products of characteristic polynomials for the Gaussian and Laguerre β-ensembles with external source, and prove Pearcey-type phase transitions for particular full rank perturbations of source. The phases are characterised by determining the explicit functional forms of the scaled limits of the averaged products of characteristic polynomials, which are given as certain multidimensional integrals, with dimension equal to the number of products.

关键词： Random matrices Dyson Brownian motion β-ensembles phase transitions

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Adapting the botanical landscape of Melbourne Gardens(Royal Botanic Gardens Victoria)in response to climate change

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Plant Diversity 2017年第6期39卷 338-347页

作者： Timothy j.Entwisle Chris Cole peter Symes Royal Botanic Gardens Victoria

Botanic gardens around the world maintain collections of living plants for science, conservation, education, beauty and more. These collections change over time-in scope and content-but the predicted impacts of climate change will require a more strategic approach to the succession of plant species and their landscapes. Royal Botanic Gardens Victoria has recently published a 'Landscape Succession Strategy'for its Melbourne Gardens, a spectacular botanical landscape established in 1846. The strategy recognizes that with 1.6 million visitors each year, responsibility for a heritage-listed landscape and the need to care for a collection of 8500 plant species of conservation and scientific importance, planting and planning must take into account anticipated changes to rainfall and temperature. The trees we plant today must be suitable for the climate of the twenty-second century. Specifically, the Strategy sets out the steps needed over the next twenty years to transition the botanic garden to one resilient to the climate modelled for2090. The document includes a range of practical measures and achievable(and at times somewhat aspirational) targets. Climate analogues will be used to identify places in Australia and elsewhere with conditions today similar to those predicted for Melbourne in 2090, to help select new species for the collection. Modelling of the natural and cultivated distribution of species will be used to help select suitable growth forms to replace existing species of high value or interest. Improved understanding of temperature gradients within the botanic garden, water holding capacity of soils and plant water use behaviour is already resulting in better targeted planting and irrigation. The goal is to retain a similar diversity of species but transition the collection so that by 2036 at least 75% of the species are suitable for the climate in 2090. Over the next few years we hope to provide 100% of irrigation water from sustainable water sources, and

关键词： Climate change Landscape succession Botanic garden Uving collection

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The effects of gonadal hormones on learning and memory in male mammals： A review

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Current Zoology 2011年第4期57卷 543-558页

作者： Stuart T. LEONARD peter j. WINSAUER Department of Pharmacology and Experimental Therapeutics Louisiana State University Health Sciences Center 1901 Perdido Street New Orleans LA 70112-1393

The primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and processes including cognition, neural development, and neural plasticity. In particular, a number of studies show that estradiol modulates dendritic spine growth and synapse density （synaptic plasticity） in the hippocampus of females, and that increased estradiol levels are generally associated with improvements on a variety of learning and memory tasks. While the majority of research has focused on the beneficial effects of estradiol in females, much less attention has been given to testosterone and its effects on learning and memory in males. Similar to estradiol titers in females, testosterone titers in males decline with age, albeit more gradually, and this decline has been correlated with impairment of certain cognitive tasks. Moreover, studies involving both humans and animals indicate that testosterone and its metabolites can augment responding on certain behavioral tasks, depending on the subject＇s current hormonal state, the response required, and the stimuli involved （e.g., those involving spatial or nonspatial stimuli）. While the exact mechanisms by which testosterone exerts its effects on learning and memory are not fully understood, recent findings suggest that testosterone modulates learning and memory in males through an interaction with the cholinergic system. The overall objective of this review is to discuss studies investigating the role of the gonadal hormones in mediating learning and memory processes in male mammals [Current Zoology 57 （4）： 543-558, 2011].

关键词： Testosterone Learning and memory Cholinergic system Mammals Cognition Androgens